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Design of Self Sustained DC MicroGrid through

Energy Audit and illumination Level Study in

Substation

Intermediate Project Report – June 2016

Energy Efficiency Research Group

An International Energy Research Foundation

Since 2015

GREEN9

Design of Self Sustained DC MicroGrid through

Energy Audit and illumination Level Study in

Substation

Intermediate Project Report – June 2016

Authors

Ashok Kumar, Chandru Mahto

Member, Energy Efficiency Research Group

Member, MGR Vision 10MW, Dr. M.G.R Educational and Research Institute

Er. R. Regunarayanan

Astt. Executive Engineer TNEB and Member , GREEN9

Dr. L. Ramesh

Chairman (BOT), Energy Efficiency Research Group

Director, MGR Vision 10MW and Professor, Dr.M.G.R Educ., & Research Inst.,

GREEN9 publication 16Ee10- June 2016

ACKNOWLEDGEMENTS

An art of manipulation of electricity power paves the way for modernizing the

world with balanced development in every aspect but the unaccounted and heedless

use of electricity, particularly in the utilization side curtailing the growth rate and

dragging the power world towards the state of energy deficit. This electrical energy

deficit should be overcome necessarily to deliver the determined growth to our mankind.

An electrical energy audit pretence us, by the way of offering technical solution to bridge

the energy deficit gap. India’s substantial and sustained economic growth is placing

enormous demand on its energy resources. The demand and supply imbalance in

energy sources is pervasive requiring serious efforts by Government of India to

augment energy supplies as India faces possible severe energy supply constraints.

Achieving energy security in this strategic sense is of fundamental importance not only

to India’s economic growth but also for the human development objectives that aim at

alleviation of poverty, unemployment and meeting the Millennium Development Goals

(MDGs).The power once generated is distributed via substation where considerable

quantum of energy utilized for lighting purpose in the society. In the proposed project a

detailed analysis was conducted in the substation yards and it’s control room .The DC

source for the protection system is fed from the battery bank interfaced with the charger

rated in ampere hours. This is the normal arrangement universally. The demerit in the

system is in the event of failure of either battery or charger, there will be posture to the

regularity of control supply to the numerical relays etc. The DC distribution to the

numerous circuits in the substation is taken from the DC bus in the distribution panels.

Normally the current taken by every DC circuit will be in mA only. When the protection

system respond to the faults by the way of activation of relays then the rate of current

flow in amps .The substation is widespread in a very large area and there is a huge

scope for the installation of alternative energy sources. Hence the micro grid concept

implemented with the addition of Photo Voltaic panels, Wind turbine, etc with the scope

of no chance to the failure of DC supply to the protection system.

TABLE OF CONTENTS

Ch. No. TITLE PAGE NO.

ABSTRACT

List of Abbreviations

List of Figures

List of Tables

01 INTRODUCTION 1

1.1 Global Perspective on Electricity Generation 1

1.2 National Perspective on Electricity Generation 1

1.3 Tamil Nadu Perspective on Electricity Generation 2

02 LITERATURE REVIEW 3

2.1 Review of Literature

3

2.2 Proposed Methodology to Conduct Audit 7

03 DATA ACQUISTION 9

3.1 Work Execution In Stage 1

9

3.2 Work Execution In Stage 2

10

3.3 University Office Audit Procedure

12

3.4 Substation Audit Procedure

13

3.5 Energy Audit At University office

13

3.6 Energy Audit at Substation’s Switchyard

20

3.7 Control room Data Observation

22

04 RECOMMENDATION 40

4.1 Recommendations on University Office

41

4.2 Recommendations on Substation

46

05 DESIGN OF DC MICRO GRID 62

5.1 Design Calculation of micro grid with PV array and Wind mill

62

5.2 Description of Micro grid

65

5.3 Case study of Proposed Micro grid

67

5.4 Analysis of Micro Grid system

68

5.5 Comparison of Existing DC system with Proposed Micro Grid

System

69

06 CONCLUSION

74

REFERENCES

75

PUBLICATION DETAILS

77

LIST OF ABBREVIATIONS

DG - Distributed Generation

LED - Light Emitting Diode

W - Watts

V - Voltage

A - Ampere

ROI - Return on Investment

ECMs - Energy Conservation Measures

ECOs - Energy Conservation Opportunities

ETAP - Electrical Transient Analysis Program

PDB - Power Distribution Board

LDB - Light Distribution Board

UDB - Ups Distribution Board

LF - Load Flow

LIST OF FIGURES

Page No.

Figure No.2.1 Final Cost Saving of lightning 04

Figure No.2.2 Final Energy Consumption saving 04

Figure No.2.3 Energy Consumption area wise 05

Figure No.2.4 Methodology to Conduct Audit 08

Figure No.3.1 Description of Project 09

Figure No.3.2 Steps Involved in Execution Stage 10

Figure No.3.3 Layout of the Existing area 14

Figure No.3.4 Energy Wastage Percentage Assessment 15

Figure No.3.5 110 KV yard layout 21



Figure No.3.8 Control room layout 22

Figure No.3.9 110KV Visual Analysis 23



Figure No.3.12 Control room Visual Analysis 25

Figure No.3.13 Present live lux level of 110KV Switch yard 25

Figure No.3.14 Present live lux level of 230KV switch yard 26

Figure No.3.15 Present live lux level of 400KV switch yard 26

Figure No.3.16 Analysis of yard lightning 27

Figure No.3.17 Total Existing load Connected(KW) 29

Figure No.3.18 Yard lightning Bus nos. VS current 29

Figure No.3.19 Yard lightning Voltage(%) VS Bus nos 30

Figure No.3.20 Control room SLD 30

Figure No.3.21 Control room Bus no. VS Voltage(%) 31

Figure No.3.22 Control room Bus no. VS Current(%) 33

Figure No.3.23 Analysis of DC SLD 33

Figure No.3.24 Load in Network 1 34

Figure No.3.25 Load in Network 2 36

Figure No.3.26 Load flow report without fault in DC system(Vol. Vs Bus no.) 36

Figure No.3.27 Load flow report without fault in DC system(Vol. Vs Bus no.) 37

Figure No.3.28 Load flow report without fault in DC system(Cur. Vs Bus no.) 37

Figure No.3.29 Load flow report without fault in DC system(Cur. Vs Bus no.) 38

Figure No.3.30 Load flow report with fault in DC system(Vol. Vs Bus no.) 38

Figure No.3.31 Load flow report with fault in DC system(Vol. Vs Bus no.) 39

Figure No.3.32 Load flow report with fault in DC system(Cur. Vs Bus no.) 39

Figure No.3.33 Load flow report with fault in DC system(Cur. Vs Bus no.) 40

Figure No.4.1 Proposed Lighting Design 41

Figure No.4.2 Wastage Audit Saving Analysis 42

Figure No.4.3 Saving with Proposed LED lights 44

Figure No.4.4 Total saving after recommendation 44

Figure No.4.5 Energy Saved with PC and Xerox machine 45

Figure No.4.6 CFL and LED comparison 46

Figure No.4.7 Rearrangement lux level in 110 KV yard 47



Figure No.4.10 110KV Tier 1 lightning 50


Figure No.4.12 110KV Cost Comparison 51

Figure No.4.13 110KV Energy consumption 52









Figure No.4.22 Total Saving of Energy consumption in yard lightning 57

Figure No. 4.23 Analysis of Control room 58

Figure No.4.24 Substation Control room with LED cost analysis 59

Figure No.4.25 Substation Control room Energy Consumption 59

Figure No.4.26 Control room Fan Cost Analysis 66

Figure No.4.27 Control room Fan Energy Consumption 61

Figure No.5.1 Proposed Micro Grid 66

Figure No.5.2 LF report without fault in DC system(Vol. Vs Bus no.) 68

Figure No.5.3 LF report without fault in DC system(Vol. Vs Bus no.) 68

Figure No.5.4 LF report without fault in DC system(Curr. Vs Bus no.) 69

Figure No.5.5 LF report without fault in DC system(Curr. Vs Bus no) 69

Figure No.5.6 Comparison of Existing and proposed(Vol. Vs Bus no.) 70

Figure No.5.7 Comparison of Existing and proposed(Vol. Vs Bus no.) 70

Figure No.5.8 Comparison of Existing and proposed(Cur. Vs Bus no) 70

Figure No.5.9 Comparison of Existing and proposed(Cur. Vs Bus no) 71

Figure No.5.10 EB per year and Cost of PV array 71

Figure No.5.11 Difference in energy consumption of EB and PV 72

Figure No.5.12 EB per year and Cost of Wind Mill 72

Figure No.5.13 Difference in energy consumption of EB and Wind Mill 73

LIST OF TABLES

Page No.

Table No.3.1 Wastage Assessment with Time 15

Table No.3.2 Total Connected load 16

Table No.3.3 Lux value Measurement 17

Table No.3.4 Room Index Calculation 19

Table No.3.5 Total Lamp Connected 28

Table No.3.6 Real time Current rating 28

Table No.3.7 DC Bus Terminals 32

Table No.5.1 Total Connected load to Micro grid 62

Table No.5.2 PV Array Description 63

GREEN 9 Project Outcome Report –16EE10

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I - INTRODUCTION

If you want to save your business energy and money then you are studying

the right report on Energy Conservation by Electrical Energy audit.

Electrical Energy audits can mean different things to different individuals. An

energy audit can be defined as a process to evaluate where a building uses

energy, by identifying the opportunities to reduce consumption as the power

consumers of the modern world start to think about the concept of “Right appliance

to the Right usage”.

1.1 Global perspective on Electricity Generation

Globally now there is an unbridgeable gap between electricity generation capacity

and the ever raising demand. The electrical energy audit is paving the way to

conserve electrical energy by the way of analyzing and adopting of standards

without any major investments. In a world becoming more global, where new

technologies foster bring faster innovations and demand changes in our

behavioural responses, the task of predicting the future becomes harder. Secure,

reliable, affordable, clean and equitable energy supply is fundamental to global

economic growth and human development and presents huge challenges for us.

Future energy supply and demand, future environmental and social contexts are

subject to a knot of uncertainties that are difficult to predict, such as the global

economic and geopolitical situations and new technical innovations[1]. Energy

saving of up to 80% can be achieved by modernizing our lighting system by

installing an intelligent light management system with day light triggered dimming

function and occupancy sensors. sincethere is a direct relationship to the cost of

the audit and how much data will be collected and analysed, and the number of

conservation opportunities identified.

1.2 National Perspective On Electricity Generation

India’s substantial and sustained economic growth is placing enormous demand

on its energy resources. The demand and supply imbalance in energy sources is

pervasive requiring serious efforts by Government of India to augment energy


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supplies as India faces possible severe energy supply constraints. Energy

requirement in our country is increasing at a very rapid rate. Holistic planning for

achieving these objectives requires quality energy statistics that is able to address

the issues related to energy demand, energy poverty and environmental effects of

energy growth.[2]

1.3 Tamil Nadu Energy Perspective

For an industrialized State like Tamil Nadu, the demand for quality power

increases exponentially and moves in tandem with the rate of economic and

population growth. As a result, the demand-supply gap is bound to persist. The

overall power situation in the State during the year 2012-13 was challenging,

eventhough the installed capacity rose from 10365 MW during 2011-12 to 10515

MW during 2012-13. Coupled with the rise in the number of consumers and their

consumption, the demand for power also steadily increased. The peak demand

for power during the year had crossed the mark of 11000 MW. The average

availability of power during the year stood at 8,500 MW. The State faced power

shortage due to the increased demand to rectify this gap the State is taking

several steps to improve uninterrupted quality power to the consumers; despite the

fact that it had faced a number of difficulties – growing number of consumers and

their consumption pattern, delay in commissioning of project, acute corridor

constraint for transmission of power and inadequate tie up with long-term sources

of power generation. Apart from this the State’s initiatives by way of effecting short

term (tenure less than 1 year) purchase of power from the local generators in

Tamil Nadu had paid rich dividends in quick time[3]. This electrical energy deficit

should be overcome necessarily to deliver the determined growth to our mankind.

An electrical energy audit pretence us the way

of offering technical solution to bridge the energy deficit gap. Energy audits are

severely undervalued. While they may be thought of as unnecessary and

ineffective, that could not be further from the truth. [4]. To cope up up this situation

local generation plays a very important role so a brief concept of Micro grid is also

discussed. Microgrid demonstrations and deployments are expanding in power

systems all around the world. Although goals are specific to each site, these

microgrids have demonstrated the ability to provide higher reliability and higher

power quality than utility power systems and improved energy utilization. [5]


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2. LITERATURE REVIEW

2.1 REVIEW OF LITERATURE

This chapter will review the various approaches to energy auditing and outline a

standard approach to organizing and conducting an energy audit. An energy audit

can be simply defined as a process to evaluate where a building or plant uses

energy, and identify opportunities to reduce consumption. There is a direct

relationship to the cost of the audit, how much data will be collected and analysed,

and the number of conservation opportunities identified. Thus, a first distinction is

made between costs of the audit which determines the type of audit to be

performed. The second distinctions made between the types of facility. In

connection to the energy conservation, audit and management, the views of the

selected researchers are presented as below.

In a paper M.Singh [6] out lined

‘electrical energy audit’ outcome of an industrial class load. According to his work

the New generation innovation and tremendous improvement in the field of

lightning has given rise to numbers of energy saving opportunities. According to

him lighting is an area which has major scope of saving energy while conducting

audit. According to his recommendation electronics chokes can be used in place

of electromagnetic chokes .they can be replaced one by one as they became

defective. metal halide lamp can be used in place of halogen and mercury lamps.

The indicating lamps also recommended to be replaced in a phased manner to

LED when existing lamps became defective. The tubes are not required during

day and should be switched off and better arrangement for the use of natural

daylight should be availed. The Right way to achieve energy efficiency is to start

planning at the design stage, use of modern efficient lamp , luminaries and gears

are also important apart from good practice. An industrial unit has been

undertaken as a case study as they are the major consumers of the power. After

case study the author has provided data in the paper which shows the different

ways of saving energy by incorporating certain changes and installation in the

present structure can make the present system more energy efficient.


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The author has also out lined that an energy auditor should see all possibilities

available in and around the proposed area. Energy conservation and exploring

new methods to reduce the demand and to save more energy can fulfill the

growing industrial demand in future. The author has also advocated that the

implementation of suggestion of energy audit can improve efficiency and thus

reduces the wastage.

Mr.S.Pramanik [7] working in the electrical engineering

department, Kalyani Government Engineering College also conducted energy

audit with similar audit recommendations. In his paper he presented very simple

ideas on energy conservation. In order to verify the ideas described in his paper, a

room size (25’x30`) belongs to the faculty members of the Electrical Engineering

has been considered as a case study. He envisaged that, the modern society is

strongly based on the energy for their economics.

Fig 2.2 Final Energy consumption saving

Fig 2.1 Final Cost Saving of lightning


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Production and supply of goods and energy consumption exercising strong effect

environmentally in local and global level which requires equitable balance

between the energy usage for the development of social welfare and the

environmental preservation. The misuse of energy and lavish handling may leads

to negative environmental impacts. The author has also stressed the need of the

energy management which is indeed the need of the hour. The conventional

resources beyond our limits might have been exhausted within some decades.

The paper has explored solutions for the energy reduction. The author has

recommended to use energy efficient appliances and implementation of

microcontroller based system along with power electronics based system which

can reduce the energy consumption. With these microcontroller based system

included in the control system of air conditioner, the percentage saving in energy

could have proven better.

A.K.Ahuja [8] along with his team conducted electrical

energy audit in the IIT Roorkee Campus and the data collected during May-

June‘09. They have conducted audit to find the new opportunities to improve the

energy efficiency of the campus. The audit was not only done to identify the

energy consumption pattern but also to find most energy efficient appliances.

Moreover, some daily practices relating to common appliances have been

provided which help them in reducing the energy consumption. The report gives a

detailed information regarding the energy consumption pattern of the academic

area , central facilities and bhawans , based on actual survey and detailed

analysis during the audit. The work comprises the area wise consumption traced ,

using suitable equipments.

Fig 2.3 Energy consumption area wise


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The ELEKTRA software was used for their audit purpose. The report compiles a

list of possible actions to conserve and efficiently access the available scarce

resources and identifying to save the potentials. The author has looked forward

towards optimization for adoption of set of mission for the authorities , students

and staff should follow the recommendation in the best possible way.The report is

based on certain generalizations and approximations wherever they found it

necessary.

According to the TS 317: Substation Design – Indoor and outdoor

lighting standard Issued in September 2014[] the technical standard is applicable

for all parties involved in the design and construction of substations. The Electricity

Act 1996 and Electricity (General) Regulations 2012, other statutory authority

requirements and relevant AS/NZS standards are the basis of TS 317[9]. For any

situation that is not covered in this standard, the requirements of current standards

including the Building Code of Australia apply. There may be additional

requirements and specifications which are project specific.

The purpose of indoor lighting is to provide sufficient light within the substation

building for normal work activities. However, for specific activities eg working in

panels, additional directional lighting may be required. The following general

design principles shall apply:

Lighting within substation buildings shall provide an average luminance of 100 to

160 lux at floor level

Typically indoor light fittings shall consist of standard single or double fluorescent

tubes light fittings.

Light fittings should be positioned such that the illuminance is spread evenly

across the building.Outdoor lighting of any SA Networks substation must fulfil the

following objectives:

Provide area lighting illumination in substation switchyard access areas

Provide illumination levels of sufficient intensity and clarity for safe movement of

personnel and their vehicles.

According to the Tennessee Valley Authority

Substation Lighting Guidelines[10] Permanent substation lighting advocated with

two-stage design. In his paper he envisaged the substation lighting system in

stages .


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The list could go on almost indefinitely, but the bottom line is that energy

management helps improve environmental quality. “Research on building energy

consumption audit and energy-saving measures for the starting point for any

lighting energy audit would be existing lighting scheme. With this input the audit

provides detailed information on retrofitting or replacing of existing luminaries, with

complete cost of project, annual energy savings and payback calculations. After

the calculations and necessary modifications, it is important to verify the luminance

levels on the task planes before and after changeover to make sure that ample

levels are maintained after the lighting system is modified. Business, industry and

government organizations have all been under tremendous economic and

Environmental pressures in the last few years. Being economically competitive in

the global marketplace and meeting increasing environmental standards to reduce

air and water pollution have been the major driving factors in most of the recent

operational cost and capital cost investment decisions for all organizations. Energy

management has been an important tool to help organizations meet these critical

objectives for their short term survival and long-term success. The measures

identified are electricity related and involve efficient lighting, power factor

improvement and control equipment besides the optimization of the contracts with

the electricity supplier. The identification of energy efficient measures that can be

implemented in a particular building requires the analysis of the energy flow in the

building, which is one of the main objectives of an energy audit. Researchers have

recommended methodology to appraise the performance of lighting systems in

terms of energy usage and optimization of energy use. If implemented during the

design stage the methodology can help in optimizing the performance of the

lighting system. It is important to think ways to manage energy intelligently and

reduce energy costs at the same time maintain required quality understanding the

opportunities and risks involved. This will help in planned decision making.

2.2 Proposed Methodology to Conduct Audit

There are many different types of energy audit methodologies that are used to

conduct the audit in an effective manner to reduce the power consumption in an

effective manner. MGR Vision 10MW is an energy awareness initiative forum that

was inaugurated in our university on 08/03/2014 this was inaugurated for reducing


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10MW generation of electrical energy. A purposed methodology is given in a flow

chart to conduct the audits in residential, commercial and in industries.

Fig.2.4. Methodology to Conduct Audit

The blocks shown above give the general steps involved in conducting the

Electrical energy audit keeping this as prime objective the work was started and

targets were fixed where collection of data was the main target so data collection

was initiated as explained in the next section of data acquisition.

Pre Site Review

Post Site Review

Data Collection

Single Line Diagram

Wastage study

Energy Management

Recommendations

Result

Outcome


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3 – DATA ACQUISTION

The power once generated is distributed via substation where considerable

quantum of energy utilized for lighting purpose in the society. The overall project

was subdivided into three stages :-

Stage 1 - “Illumination Level Study and Energy Assessment Analysis at

University Office”

Stage 2 - “ Analysis of Existing Dc System In ETAP”

Stage 3 – “ Design Of Self Sustained DC Micro Grid”

Fig 3.1 Description of project

3.1 – Work Execution In Stage 1 :-

The first phase of an energy audit started with site inspection work. The

measurements in all aspects have been taken for reckoning actual value of

prevailing luminous intensity level of the office. In this paper the details of possible

technical viability are analyzed and scope of saving both energy and cost has

been done through auditing in the university office. The first initiative is for going

for pre-site work, in this first we decide the location were to conduct this energy

audit in home, industry, schools etc. In this paper the first initiative we done is

doing auditing in university office and giving them a appropriate results and


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recommendation and suggestion regarding their usage of electricity and also

making an assumption to reduce the tariff of electricity bill. To create energy

awareness to the general public, Dr. M.G.R Educational & Research Institute,

University Chennai has taken initiative called ‘MGR Vision 10 MW’ under

leadership of Dr. L Ramesh to save 10 MW in 10 years. This work is the pilot

study work of Vision 10 MW. This study covers the waste audit analysis and

recommendation for the University office in the first stage.

3.2 Work Execution In Stage 2 :-

Fig no.-3.2 Steps involved

An innovative analysis of illumination level in the substation’s yard and control

room has been taken as a part of electrical energy audit and also the DC system

interfacing with the micro grid ,carried out with purpose oriented. In 400 / 230-110

KV substation, widespread in 83.33 acres comprising 3 yards of 400KV, 230 KV

and 110 KV and one control room with external bifurcation for battery room, LVAC

room, cable room, PLCC room , this project study undertaken. The substation


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switch yard spread over 60 acres approximately and is divided in to separate bays

for respective feeder control and some left for transformers associated with switch

gears . The EHV outdoor substation like 400 KV is subjected to high

electromagnetic radiation due to which the metal members are inducted with

mutual and self induction. The lighting in the substation yard requires special

design and study in such a way that illumination system should be adequate to

carryout emergency and night patrolling work without hindrance in the operational

point of view and make comfort to replace the failed equipment. The erection of

lighting fittings needs safer distance from the live equipments and bus, considering

all aspects of electrical safety too. The proposed paper dealt with an attempt

exercised with efficacy keeping an eye towards possible merits oriented energy

conservation. The method of two tier lighting in the yards, a new concept is taken

for analysis. This two tier lighting control is an innovative step to illumination

control where minimum lux value is maintained when no physical activity in the

any of the switch yard. That is referred as first tier of lighting system which is dim

level lighting. In the second tier lighting system is proposed when there will be

activity in the yards either routine or emergency, then adequate luminous intensity

will be maintained by other set of lighting system prescribing standards of

stipulations. The electricity generation power houses and substations are the

primary origins where judicial way of utilization of electricity should be started with,

and it shows a good sign to the consumers. Even the concepts of energy audit is

basically similar, but while adoption in the detailed audit, the methodology varies

industry to industry and concern to concern, and all basically depends upon the

energy auditor’s high profile in his discipline dealt with. The energy conservation is

partially depends psychological attitude of the society too. The proper awareness

and imparting knowledge through possible social means necessarily to reach

every common man to do energy conservation through his or her attitudinal

change with the energy related appliance right usage to practicable extent. In the

EHV substation audit study, the the present provision of lighting fitting on the

gantries which supports the connecting jumpers to the feeders etc, creates

inflexibility for maintenance personnel during replacement. And in safety point, this

method of light fittings spread in gantries not technically supportive. Instead of

studying uniform luminous level, the fittings are installed in random wherever

possible. This analysis, supported through the modern software, reveals the fact


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that the extent of possibility to make the lux level moreover uniforms without any

investment, just by relocating the fittings in the gantries itself. And in the analysis

‘with investment’ new system of lighting called ‘ Two tier system’ in which only

LEDs proposed to be installed. Another concept of poly vinyl chloride wrapping of

metal post from bottom to top are proposed to enhance the life of the lamp post

and prevent it against the soil corrosion and miscellaneous induction etc. As

already illustrated normal steel pole when exposed to environment subjected to

corrosion, that too the rate of corrosion is of higher magnitude where the metal

joins with earth. The corrosion rate still more stimulated due to the higher rate of

stray induction by the external field. In order to prevent the corrosion, an external

wrapping of polyvinyl chloride over the steel pole, both externally and internally. In

addition it adds mechanical strength.

3.3 University Office Audit Procedure

The data collected revealed the possibility of energy saving in the office envelope

of total area of approximately 225 square meters. This paper projects with energy

audit recommendations in the later part. The steps involved in the execution of

electrical energy audit are as below.

level calculation for the proposed area


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3.4 Substation Audit Procedure

To conduct substation audit the first work is to design the layout to conduct the

audit as shown in the chart given below in which the procedure how to conduct an

audit and to the manage it in an effective manner

A step by step procedure is adopted to carry out the audit. The steps involved are

1. Preliminary and detailed study in the control room area and all switch yards

2. Design and analysis of existing lighting system in VISUAL software.

3. Practical live lux level calculation.

4. Analysis of power flow to the luminary fixtures via SLD in ETAP

5. Design and analysis of proposed system in VISUAL software.

6. Analysis of the DC system in ETAP

7. Designing of Micro Grid for new system

8. Recommendations

3.5 Energy Audit At University office

I. DATA OBSERVATION

The first phase of an energy audit started with site inspection work. The

measurements in all aspects have been taken for reckoning actual value of

prevailing luminous intensity level of the office. In this paper the details of possible

technical viability are analyzed and scope of saving both energy and cost has

been done through auditing in the university office. The theoretical level of

illumination required as per the standards which studied with the actual level.

Every appliance has been subjected to audit and aggregate load details were

prepared. The room index for every partition was calculated and LUX levels were

recorded. The analysis of energy wastage in the university office was also done

on the merits of data collected by visiting different timing over the span of a week.

The data collected revealed the possibility of energy saving in the office envelope


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of total area of approximately 225 square meters. This paper projects with energy

audit recommendations in the later part.

1. Preliminary study about the prospective area

The following layout shows the university office and the way of spread of lighting

system. The load details with respect to room also explained further. The office

was subjected to electrical energy audit and solutions devised. The overall area

was divided into various segments named from A-K.

Fig3.3: layout of the existing area

Here mainly seating arrangement for most of the staff is in ‘K’ segment. The

prospective auditable area was calculated both in sq.feet and square meters. The

total area of the office comprises of 2470 sq feets with a staff strength of 40. Out

of that the major area is covered by the area “K” which is around 903 sq feets. “A”

is of 121sq feets , “B” is of 110 sq feets, “C” is of 130 sq feets, ‘D” is of 100 sq

feets, ‘E” is of 110sq feets, ‘F” is of 120sq feets, “G” is of 80 sq feets, “H” is of

264 sq feets, “I” is of 121 sq feets, “J” is of 33 sq feets, “L” is of 378 sq feets.

II. . WASTAGE AUDIT

This step is to ascertain the scope of the possible saving of energy during the

working hours of office. As to acquire reliable data, periodical visits have been

paid in different time slots and observed the nature of load running waste and

accounted its ratings. The computed consumption also worked out. An

independent enquiry also conducted without revealing the purpose among the


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staff to ascertain their style of functioning with energy equipments and also

collected the factors influencing the wastage of energy particularly in respect of

the operation of Photostat , personal computers etc. The average pattern of

energy running waste is tabulated below.

Table 3.1 : Wastage Assessment with Time

Time Fans Lights Rating (watts)

9:15 - 10:15AM 3 10 1260

10:30 - 11:15AM 2 12 1416

11:15 - 12:15PM 2 10 1200

12:15 - 1:15PM 3 12 1476

01:30 - 2:30PM 2 11 1308

02:30 - 4:00PM 1 10 1140

04:00 - 05:00PM 2 10 1200

05:00 - 06:00PM 2 8 984

Fig3.4: Energy Wastage Percentage Assessment

The graphical representation of the wastage audit with the data collected from the

university office has shown. From the table it can be vividly seen that the

maximum wastage occurs during 9.15 to 10.15 Hours, in the morning which is

being because of the college work starts from 9:30 but the equipments are

switched on by 9:00 hours and there is only one person who is switching on and

off all the lights and fans regularly. Considerable wastage occurs during 12:30 to

1:30 which is lunch time, while most of the equipments left in switched on state


II-16

but less staff were found in the office. So here it can be seen that just due to

unawareness and ignorance precious energy is being wasted which can be

minimized by taking proper care. It is estimated that, by the way of effective

utilization around 10 kWh per day can be saved which roughly works out to the

figure of 3000 kWh units per annum. If the cost per unit is Rs 7 then estimated

saving of Rs 21000 per annum which reminds the proverb ‘ Little drop makes an

ocean’ . Already the office enclave is air-conditioned fully, hence under normal

conditions fans are not necessary. But considering extra ordinary occurrence in

the event of air-conditioning failure, the usage of fans can be opted. However

such a view not taken in to account in this audit study for calculation of saving

aspect. But reiterating to keep fans in off when office enclave in air conditioned

mode. Then the estimated saving will be higher.

Connected load

The table given below shows the total connected load of the office. From the

graph shown it can be easily depicts that the max energy consumption is due to

the UPS, The lightning on a whole adds a total load of 3KW in addition with fans,

computers the minimum consumption by the printers

Table 3.2: total connected load

Sl

No

Description Total

nos

Wastage Total

Load

1 CFL fitting

16 36 576

2 Sq. fitting

19 108 2052

3 Doom fitting

3 120 360

4 Photostat machine

1 300 300

5 Ceiling fan

20 60 1200


II-17

6 Split A/c machine

3 2500 7500

7 Desk top computers

8 250 2000

8 Water purifier

1 300 300

9 UPS system 1 7.5KVA -

-

1 7.5 KVA ----

TOTAL LOAD

14.288 KW

C. Practical lux level

In fact it was conducted adopting two methodologies.

1. Measurement of actual level of lux at the center of the every working surface and

Tabulated. The lux level is measured at every working table. Among these

measurements it was noticed that the lux measurement level was below the

required value in a8 and b5 working table.

.

2. Measurement carried out in each cabin and hall, corridor etc as per the calculated

room Index and analyzed.

The available luminous intensity level of the corridor is more than the prescribed

level.

The illumination level of the office is non–uniform which can be improved by the

way of installing distributed illumination rather the single, single fixture or using

louvers.


II-18

Table 3.3 Lux value measured

Room index: According to the bureau of energy efficiency ‘room index’ is the

number that describes the ratio factor of the room length, width and height.

SEGMENT AREA LUX LEVEL MEASURED AT WORKING

SURFACE

A ROOM 104

B ROOM 101

C ROOM 132

D ROOM 250

E ROOM 233

F ROOM 205

G ROOM 214

H ROOM 140

I ROOM 198

J ROOM 255

K OFFICE

HALL

a1: 124 b1 125 c 1 176

a 2 122 b 2 141 c 2 160

a 3 142 b 3 127 c 3 160

a 4 129 b 4 106 c 4 138

a 5 115 b 5 95 c 5 150

a6 135 b 6 110 c 6 155

a 7 110 b 7 127 c 7 164

a 8 92 b 8 150 c 8 155

L CORRIDO

R

NO WOKING TABLE


II-19

Room index= (LxW) / (Hm(LxW))

L= length of the room , W= width of room , Hm= mounting height.

It doesn’t matters whether the dimensions are in meters or not, but the unit should

be same for all. The minimum number of measurement point can be ascertained

from the table shown below

Table 3.4 Room Index Calculation

Segment Description Prescribed

Level of Lux.

(advocated

Value)

Room

index

Meas. Reqd.

A ROOM 100 to 200 0.50 9

B ROOM 100 to 200 0.48 9

C ROOM 100 to 200 0.51 9

D ROOM 100 to 200 0.45 9

E ROOM 100 to 200 0.48 9

F ROOM 100 to 200 0.50 9

G ROOM 100 to 200 0.40 9

H ROOM 100 to 200 0.69 9

I ROOM 100 to 200 0.50 9

J ROOM 40 to 60 0.21 9

K OFFICE 100 to 200 1.28 16

L CORRIDOR 50 to 75 0.56 9


II-20

As per the Code of practice of interior illumination – IS 3646-1 (1992) room index

is required to get the numbers of reading required to measure the theoretical lux

level of the proposed area. Using the above facts the required numbers of

reading are taken and tabulated as shown above.

Measurement carried out in each

cabin and hall, corridor etc as per the calculated room index and analyzed. Lux

level measured at every working table. In such measurement it was noticed that

the lux measurement level was below the stipulated value in a8 and b5 table.

Hence both the seat may be rearranged accordingly The available luminous

intensity level of the corridor is more than the prescribed level.The illumination

level of the office is not uniform which can be eliminated by intelligent lighting

system

C. Constraints for optimal lighting

The wall with brown wooden coverage even though appears good not supporting

for effective lighting spread due to more rate of diffusion and not supporting gross

illumination. The lights are provided above the two fans in ‘K’ segment may be

rearranged to improve shadowing effect which will be quiet annoying. In spite of

its technological merits in all aspects , it seems impractical to suggest all lighting

fittings by light emitting diode lamps owing to the initial high cost

3.6 Energy Audit At substation’s Switchyard

Preliminary study in the prospective area

A substation is an indigenous system normally before the electrical power left to

the consumer’s choice of utilisation. Substations do the function of

transform voltage level from higher to lower or vice versa to carry out specific or

generalized purpose oriented activity. Here the EHV substation comprises 400 KV,

230 KV, 110 KV switch yards with a control room. The switch yards are

geographically spread facilitating the drawl of feeders to other substations and the

switch yard of the generating stations.

https://en.wikipedia.org/wiki/Voltage


II-21

a. SWITCH YARDS LAYOUT

Among the switch yards of different voltage level, in the 110 KV yard comprises

twelve bays with the equal width of 9.18 meters and the last bay in south and north

side of 110 KV yard are at a distance of 16.76 meters and 19.8 meters

respectively from the bilateral roads.

Fig-3.5 110 KV yard layout

Fig: 3.6 230 KV yard lay out


II-22

Fig 3.7 400KV YARD layout

There are 26 sodium vapour lamps each rated 250 watts are provided on the top

of the gantries. The location of lamps is marked with circular point and the

numbers of light fittings are shown in figure 1.1.The 110 KV yard is spread in

16060 square meters. The 110 KV switch yard is designed for double bus with bus

coupler and single breaker system .The 230KV yard comprises 12 bays each bay

is of 14m length the distance between first bay and the outer boundary is of 7.6m

and the last bay to outer boundary is 12meters.The 230 KV yard consists of total

52 sodium vapor lamp provisions. The lamp location and the area layout is as

shown above in the fig.1.2. The extent of 230KV yard is around 20116 sq meters.

The arrangement of switch gear is as like 110 KV yard. The design of 400 KV

yard is double bus one and half breaker system arrangement. The total spread of

400 KV yard alone is 110336 sq.meters. In the 400 KV yards the are numbers of

mercury vapor lamp fittings and numbers of sodium vapour lamps. The illumination

level in the three yards are not uniform in our vision and also the fittings are

provided in groups where ever easy possibility at a height of about 8 meters. The

low tension supply to the switch yards connected from the 500 KVA station

transformers from the local 110 KV substation with back feeding arrangement.

3.7 Control room Data Observation :

Control room is widespread into 515 square meters. All the control & relay panels,

RTCC panels, GPS system, SCADA system , communication panels, RTU, fire

protection annunciation panel etc are housed inside the control room logically in


II-23

operation point of view. The control lightning design was done by one lead

concern in early 2000 with the spread of 65 twin lamps fittings of 40 watts

fluorescent 4 feet tube light. Thus total FTL lights in operation are 130 numbers

.

Fig3.8- CONTROL ROOM LAYOUT

I. Design and analysis of existing lightning system using Visual software.

a) Analysis of Yards

The diagram shown below is the illumination level analysis of 110KV, 230KV &

400KV yard done in VISUAL Software.

FIG-3.9 110KVVISUAL ANALYSIS


II-24

FIG-3.10 230KV VISUAL ANALYSIS

FIG-3.11 400KV VISUAL ANALYSIS

On Analyzing the three Yards in the software it was found that the value of lux

obtained in the yards are not as per the prescribed value on par with the standards

the value of lux for the outdoor yard lighting which around 30 lux but the maximum

value of lux obtained is 20 lux below the lights and on an average value in each

yard is only 14lux. This lighting system not supporting the purpose for which these

are erected and annoy the working environment. In the figures also it was evident

due to dark patches. So it is recommended to change the fittings with higher

lumen value or on the other way reducing the height and it is better to go for

rearrangement of fittings so that the lux value obtained would be fair to carry out

operations even at night.


II-25

b) Control Room

The picture shown below gives the illumination level analysis of Control Room via

VISUAL Software. Fig 2.7 shows the value of lux obtained in the control room.

However the average lux value obtained the control room is around the prescribed

value but the FTL fitting used in the control room becoming generation old model

and each fittings consists of twin lamps consuming of around 80W of power. The

same value of lumens can be obtained with less consumption of electrical power

by the presently available lights in the market. So in the recommendations it is

proposed to change the fittings with LED lamps where each fitting will consumes

below 40W of power consumption with long lasting life span about 50000 burning

hours without appreciable reduction in its luminous output. As in the control room

activities will go ahead in shifts, hence the lights are operating round the clock.

That will a reason, that the cost incurred for replacement will be got back within

short payback period.

FIG-3.12 CONTROL ROOM VISUAL ANALYSIS

II. Practical live lux level calculation –

a) Yards live lux calculation

The value of lux was calculated by the application of user friendly software. In fact

many equipments and devices are spread in, both at yards and the control room

which pose obstructions for ground level lighting, however that aspect was not

accounted while analyzing the lux level through VISUAL software. So a manual


II-26

calculation was also carried out using the lux meter and the output obtained are

shown in layout diagram.

Fig3.13- Present live lux level of 110KV switch yard

Fig: 3.14-Present live lux level at 230 KV switch yard

Fig 3.15.Present live Lux level at 400 KV switch yard


II-27

Data collection for the manual analysis of luminary fixtures started from the

measurement of 400 KV, 230 KV and 110 KV yards. In the twelve bays in 110 KV

yard comprises of twelve numbers of bays where the average values of lux

measurements seen as 14 lux. In the 230 KV yard also measured average lux

value will be 16 lux only. In the 400 KV yard the illumination level in average

accounted less than 20 lux. Either due to the present way of spread of lighting

fittings not supporting to attain the standards of outdoor lighting of switch yards of

minimum 50 lux level. The actual measurements of lux in the switch yard using the

digital lux meter have been taken after 20 hours for reliable values.

b) Control Room live lux level calculation

The control room is a centralized air conditioned hall with an area of 515 square

meters and distributed with the numbers of twin fluorescent lamps designed

optimally and the lux level is adequate. The twin FTL fittings fixed in false ceiling of

control room. The lighting design inside the control room with measurement of

luminous intensity is as per room index . The room index of the control room

worked out as approximately 3.

Room index: According to the bureau of energy efficiency ‘room index’ is the

number that describes the ratio factor of the room length, width and height.

Room index= (LxW) / (Hm (L+W)) = 3 for control room.

L= Length of the room , W= Width of room , Hm= Mounting height.

It doesn’t matters whether the dimensions are in meters or not, but the unit should

be same for all As per the Code of practice of interior illumination – IS 3646-1

(1992) room index is required to get the numbers of reading required to measure

the theoretical lux level of the proposed area.


II-28

Analysis of luminary fixtures via SLD in ETAP –

[1] Yard lightning

Fig 3.16 Analysis of yard lightning

The SLD shown above gives the complete connection of lights in the yard here we

can easily identify that the main bus is overloaded and also the cables are

overloaded in 400 KV Yard there is no seprate switch connected so when the

lights ar eon all are on at the same time even if not on use this leads to heavy loss

also for the safety point of view it is not tolerable. Th Real time reading obtained

from the meter connected is tabulated in the coloumb below.

Table -3.5 Lamp connected

In 400KV yard 77 sodium vapor lamp are used and 19 metal halide lamps are

used and all the lights are in function. In 230KV yard 35 SVL are used and in

110KV yard 15 SVL are used. In 110KV and 230KV yards no metal halide lamps

are used. Single line diagram of the present connection of lightning fixtures was

drawn and analyzed in ETAP software. It was found that the controlling switches

for the entire outdoor lighting system provided in two locations. In the given single


II-29

line diagram analysis it is found that the 110KV yard consumes 5KW of power ,

230KV yard consumes 12KW of power and 400KV yard uses 16KW of net power

being consumed in lightning. There is no separate arrangement of switch in 400KV

yard all the lights will glow together whether in use or not. In 110KV yard and in

230KV yard a single switch control given for complete yard. The Measurement of

ampere at night at two locations is furnished below.

Table-3.6 Real time current rating

Here it can be noticeable that the three phases are not equally loaded which

needs rearrangement in connection with similarity in loading.

Fig 3.17 Total Existing load Connected(KW)

The above graph shows the net connected load on the system. The major

consumption of load is by DC system then FTL consumes 23% of total load and

then the minimum consumption of power is by fan as there are only three fans

each of 100 Watts.

23%

2%

75%

FTL

Fan

DC load System


II-30

Graph of yard lights and voltage

The existing system of yard lightning was analysed in the etap and the value of

voltage abd current obtained in response to the bus numbers are as shown below.

Fig. 3.18 Yard lightning Bus nos. VS current

The graph shown above gives the complete detailed analysis of yard current Vs

the buses number here we can easily identify that the current used by different

buses are not equal as load distribution is not equal. Here bus 33 and bus 3 is

heavily loaded.

Fig. 3.19 Voltage(%) VS Bus nos.

0

10

20

30

40

50

60

Am

ps

85

85.5

86

86.5

87

87.5

88

88.5

89

89.5

90

1 3 5 6 10 11 12 15 16 17 18 19 20 28 34

Vo

ltag

e(%

mag

)

No, of buses


II-31

The graph shown above gives the graph of bus number Vs Voltage. Here the

variation in the value of the voltage is around +/- 5% ehich isn under the specified

value.

[2] Control room lightning

Fig 3.20 Control room SLD

The above SLD is of Control lightning Here each light connected is of 36 watts the

light used is FTL lamps. The graph of voltage and current obtained is as shown

below.

Control room graph for voltage and current

Fig. 3.21 Bus no. VS voltage(%)

99.5084

99.5086

99.5088

99.509

99.5092

99.5094

99.5096

99.5098

99.51

99.5102

BU

S93

BU

S96

BU

S99

BU

S10

2

BU

S11

6

BU

S11

9

BU

S12

2

BU

S19

2

BU

S19

5

BU

S19

8

BU

S20

1

BU

S21

5

BU

S21

8

BU

S22

1

BU

S22

4

BU

S24

9

BU

S25

2

BU

S25

5

Vo

ltag

e(%

Mag

).


II-32

The above graph gives the value of bus number Vs voltage here almost the value

of voltage obtained is constant.This gives that the system is well connected and

properly loaded.

[3] DC Measurement

The power without protection is a useless’ is technical proverb normally spoken

among the power engineers. In every sub station, two battery system associated

with charger so called the main-1 protection system and main-2 protection system

are the normal systems used exclusively for protection circuits. Both the circuits

are separated and provided with the intension if any one system fails other

protection will act in event of fault. The operation of circuit breakers through the

tripping and closing coils are done by DC supply. The indication and annunciation

circuitry also being operated by direct current supply. Except the power flow in

alternating current transmission towers, the complex circuitry for the protection is

powered by direct current circuitry. In 400 KV substation, there are two sets of

batteries connected to independent system of charger normally 220 Volts, 600

ampere hour rating. During normal condition the batteries left in the state of

‘Floating’. The D.C system bus bar is used for pairing number of direct current

connections for the different protection schemes like overload protection , distance

protection, differential protection , over voltage or over flux protection, fire

emulsifier protection etc. Normal condition the D.C supply is used for the

operating voltage for the numerical relays. During fault conditions the respective

operating circuits energized by the other set of D.C supply causing to execute

desired protection related operation. Audible alarm and SCADA operations are

also being done by DC power extracted from battery and charger. The operation of

transducers , the power transformer protective system are based on D.C supply.

Hence maintenance of batteries are important as per the manufacturers directives

and the condition of battery charger should be taken care by selecting the mode of

‘boost’ and ‘ float’ which has to be decided as per values of specific gravity and

individual voltage per cell.


II-33

DC SLD

The data taken for the drawing of SLD in ETAP is as given below

Table no.3.7 DC Bus terminals

No. of

Ferrules

DC Bus terminal

Number

Ope rating

Voltage(V)

Net current

consumed

(mA)

Total power

consumed(kw

)

84 DC Bus Terminals 1 220 37480 8.2456

84 DC Bus Terminals 2 220 28240 6.2128

As observed in the DC system there are total of 188 connections the overall

connection was placed in a two DC bus system in first system there are total of 84

connections as in the bus two. The operating volatege is found to be fixed at 220V

and the net current consumed by the susyem is around 65720mA. The net power

consumed by the DC system itself is around 15KW. This existing system is

analysed in ETAP software and the complete dtails is explained in next sections.

Etap Analysis of complete DC system

Fig 3.22 DC SLD


II-34

As shown above the net load connected to the DC system is bifurcated in two

networks network 1 and network 2. The load connected in the network one and

network two is as shown below:-

Network one

Fig 3.23 load in network 1

Network two

Fig 3.24 load in network 2


II-35

On analysizing the above system following draw backs in the present system :

1. The source for charging will be only through charger . In case if there ll be very

long interruption of input supply then the battery supply may be drooped which will

leave the protection system in to peril.

2. In the absence of standby charger, if any serious fault happened in the charger

then there ll be question for power system protection.

3. In the DC protection system in the major EHV substation , there will be more than

35 to 40 pairs of different tapping from the DC distribution bus for the various

scope of function and each pair normal requirement in milli amperage will also

different from each other.

4. During the device or numerical relays operations the DC burden requirement will

be manifold.

5. In even of operation of ‘bus bar protection scheme’ or ‘ local back up protection’

(LBB)

6. The amperage burden dragging from the DC source will be in quantum of amperes

only

7. In the proposed scheme taken for discussion in the paper , an Direct current micro

grid has been formulated and micro wind turbine , PV panels, DG generator all

incorporated within the micro grid along with the battery set interfacing with

conventional chargers connected with AC source.

8. The purpose will be strong DC source for the protection system in the event of any

black out or brown out happening in the transmission system. The main sources

to be wind mill or solar energy.

9. In this paper, it is taken for discussion that in so called DC micro grid the analysis

of absence of one source after other and also the requirement of burden during

the operation of protection system in every possible aspects.

10. The proposal of operation of DC lighting in the control room from the DC micro grid

also taken for simulation.


II-36

11. In the 400 KV substation control room calculated with 65 twin 4 feet LED tube

lights taken for the simulation . The DC regulator also proposed to be provided for

continuous supply.

12. The graph obtained for the voltage and current Vs bus number is as shown below.

Graph of dc system for voltage and current

The complete analysis of the DC system was done in two stages in first stage only

those loads were taken into account which are static to the system further faults

were applied and a again the system was analysed.

1. First analysis dc bus voltage VS no. of buses

Fig. 3.25 Load flow report of DC load system without fault

The Graph shown above gives the Variation of voltage VS bus numbers of first

network. The variation was found to be within the prescribed limit of +/- 5%. This

demonstrates that the system is working properly with connections provided.

218.9

218.95

219

219.05

219.1

219.15

219.2

219.25

14 18 22 24 26 29 31 33 35 37 39 41 43 46 48 50 52 55 57 60

Vo

ltag

e(V

)

No. of buses


II-37


The Graph shown above gives the Variation of voltage VS bus numbers of first

network in continuation to the first graph second graph gives the variation in

second network. The variation found in the above graph is within the +/-5% which

is under the given specified value.

2. Analysis bus current VS nos. of buses


The graph shown above gives the variation of current VS number of buses. The

load shown above gives the network one.

218.85

218.9

218.95

219

219.05

219.1

219.15

219.2

219.25

219.3

219.35

62 64 66 113 115 117 119 121 123 125 127 129 131 133 135 137 139 141 143 145 150

Vo

ltag

e(V

)

No. of buses

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

18 22 24 26 29 31 33 35 38 40 42 45 47 49 51 55 57 60 62 64

Cu

rre

nt(

amp

s)

No. of buses


II-38


In continuation to the graph one of network one second graph gives the variation

for second network . The output graph is shown in the above diagram and the

variation obtained in the existing system is shown.

3. Third analysis bus voltage VS nos. of buses during five fault

Fig. 3.29 Load flow report of DC load system with fault in five bus

The above graph shows the variation of current VS numbers of buses for

connection in network one.

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1

65 112 114 116 118 120 122 124 126 128 130 131 133 135 137 139 141 143 145

Cu

rre

nt(

amp

s)

No. of buses

0

1

2

3

4

5

6

7

8

18 21 22 23 24 25 26 28 29 30 31 32 33 34 35 37 38 39 40 41 42 43 45 46 47 48 49 50 51 52 55 56 57 58 60 61 62

Cu

rre

nt(

amp

s)

No. of buses


II-39


The above graph shows the variation of current VS numbers of buses for

connection in network two. It is clear from the above two graph that the 21 ,120

,126 , 124 and 137 are loaded heavily then the other buses which leads to the

higher current consumption in the system.

4. Third analysis bus voltage VS nos. of buses during five fault


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

63 65 112 114 116 118 120 122 124 126 128 130 131 133 135 137 139 141 143 145

Cu

rre

nt(

amp

s)

No. of buses

218.9 218.95

219 219.05

219.1 219.15

219.2 219.25

14 18 22 24 26 29 31 33 35 37 39 41 43 46 48 50 52 55 57 60 62 64

Vo

ltag

e (

volt

s)

NO. of buses


II-40

Fig.3.32 Load flow report of DC system with fault in five buse

The above graph shows the variation of voltage VS numbers of buses for network

one and network two. In network one the voltage varies from 219.2 to 218.9 which

not of much difference but in network 2 there is a sudden drop from 220 to 208V

this may be due to improper cable connection to the system. Based on the data

observed in the above sections new methodologies were advised to adopt in the

further section of recommendations.

200 202 204 206 208 210 212 214 216 218 220 222

65 112 114 116 118 120 122 124 126 128 130 132 134 136 138 140 142 144 146 152 167 169 171

Vo

ltag

e (

V)

No. of buses


II-41

4 – RECOMMENDATIONS

Recommendation is an act of suggestion or proposal as to the best of course of

action , especially one put forward by an authoritive body[6].In this methodology

the data aqua station is done by collecting data in a residential house, commercial

building and industries the data collection i.e. is collected gives the layout of usage

of electrical energy. The wastage of energy can be easily monitored and the

recommendation ideas with new forms of implementation of renewable energy in

effective manner to reduce the power demand and also motivating people to

undergo renewable energy resources. In these methods the tariff details, wattage

of each appliance, daily utilization chart, single line diagram and real time load

analysis etc. The details of these charts are given below with brief explanations.

The recommendation are designed in three manner and they are given below as

follows

Recommendation Without Investment

Recommendation With Investment

Recommendation with DG

These are some general tips to save energy at University and Substation.

1. Proper dusting and cleaning of exhaust fan should be done.

2. Instead of two fans you can replace it to one which you use frequently.

3. Instead of three CFL used in hall only one CFL can be used as the other two are

not necessary.

4. Decoration light should be especially used only occasionally

5. Use timer facility to save energy

6. Orient fan is placed in the room but the distance of light from the wall is not

proper.

7. You can use table fan as the room size is 25sqft only.

8. Instead of CFL used outside you can install LED bulb as it consume less energy.


II-42

9. For air conditioner use windows with sun films and curtains

10. Don’t set your thermostat at a colder setting than normal when you turn on your air

conditioner. It will not cool your home any faster and could result in excessive

cooling.

11. Seal the door and windows properly.

4.1 Recommendations on University Office

A. Proposed Layout

:

Instead of recommending all lamps to be replaced by the present modern

technology energy star rated LED lamps which possess long span of life up to

50000 hours and environmental friendly, but due to the factor of cost ,it is

suggested the first phase of conversion for k segment, the main staff working area

and for the corridor as shown replacing 36x3 ( 108 w ) fluorescent fitting by

24x3(72w) . By these replacement, the luminous level will be more over same with

lesser involvement of cost. The system of LED can also provided with presently

available electronic control gear. The use of modern concept of lightning including

the use of daylight offers up to 75% potential to save energy.

Fig 4.1: Proposed Lighting Design


II-43

B. Recommendation without investment:

1. Wastage Recommendation: The wastage audit reveals the fact that the

practice should be imparted that when leaving working table everyone should be

bound to switch off the lights and fans. There is considerable saving in long run. In

this audit, there will be estimated saving of 3000 kWh per annum which is roughly

saving of Rs 21000 per annum. Briefly to say that

All the equipment should be switched off when not in use.

Fans should be switched off when the AC is ON. It is advocated to keep a slogan

display on energy conservation in every one’s view with a advice of keeping fans

off when air condition system is operative.

Usage of minimum lights in the segment C, D, E , F ,G during day time because of

sunlight availability.

Fig.4.2 : Wastage Audit Saving Analysis

2. Rearrangement Recommendation:

It is seen that two lights are connected above the fans in segment ‘K’ and should

be rearranged to improve illumination and avoiding possible rotational shading

while the fan is rotating.

0

10000

20000

30000

40000

50000

Before wastage audit After Wastage audit

Wat

t H

ou

r

Energy wastage in watt Energy saved in watt

y y y y y


II-44

a) Matching the proper lamp type to the respective work task , consistent with

color , brightness control and other requirements..

b) Establishing adequate light level without compromising objective and safety.

c) The decorating lighting fitting (TL-3nos) of 120 watt in the corridor normally

recommended to be kept off, except on special occasions

.

3. Recommendation with PC and Photostat Machine: According to the survey

of the wastage audit conducted by the energy audit team, it is noticed that most of

the system and the Photostat machines are left in the sleep mode. Hence, energy

is wastage in the form of no load loss. So the additional energy saved is used to

shut down the unit when there will be no work with it for longer period. The

computer systems, printers and Photostat machine are used effectively for 6 hours

in a day in the university office and left two hours in sleep mode as observed in

audit study then the energy loss will be more than 80 units per month.

Audit Observation: The energy saving per annum by avoiding sleep mode in PC

and Photostat machine is 960 units.

C. Recommendation with investment:

1. Recommendation with LED light:

In any energy audit report, if it fails to envisage to adopt modern efficient system at

least at its preliminary level in the area of the audit, then the suggestions and

directives are not up to the present technological yard stick. Hence it is

recommended to replace the existing 9 florescent lamp fitting of 108 watts in to 72

w in ‘K’ segment and 1 number in ‘G’ segment. These lamps are environment

friendly as it does not possess mercury and energy efficient. The life of the star

rated LED lamps will be more than 50000 hours. By this replacement using LED

lamps, estimated energy saving will be 1290 kWh per year. Considering the cost


II-45

implication for conversion to LED lamps apparently thrice of other fittings, first

phase of conversion is suggested only for main staff working segment.

Fig 4.3 :Saving with Proposed LED lights

The given chart stresses that if we properly switch on and off the lights and avoid

using lights during day time will save the load of 1124 watt without any investment.

Audit observation:

Cost equivalent of 1290 unit per annum can be saved by the LED lamp

replacement.

2.Recommendation with Fan:

The energy audit team found that the fan installed in the in office is not star rated.

Available fan is consuming 60 W. It is recommended for replacement with energy

efficient star rated fan which will be available for 50 watts per fan. If the fans are

replaced by star rated fans in a pace manner the savings in that aspect will be:

Fig. 4.4 Total saving after recommendation

3300

2100

0

500

1000

1500

2000

2500

3000

3500

Existing CFL Proposed LED Light

Y

X

0

1000

2000

3000

4000

5000

wastage audit Reaarangement PC and xerox Total

kWh

r/Y

ear

Y


II-46

Difference in watt = 10 watt

Saving =700 kwh per annum

.

Audit Observation: From the above data analysis, the possible saving of 700

units per annum is achieved, by

Replacing the old fans by new fans.

3.Recommendation with PC and Xerox machine:

The graph shown below gives the quantum of saving if the staff not preferred the

sleep mode in personal computers and Photostat machine.

Fig. 4.5 : Energy saved with pc and Xerox machine

Audit Observation: From the above data analysis, the possible saving of 900

units per annum is benefited, if the operator of PCs and Photostat machines are

not preferring sleep mode.

0

200

400

600

800

1000

1200

1400

1600

Energy Saving in PC Energy Saving in Xerox

Machine

Total

Wh

/Da

y

Y


II-47

Fig. 4.6 : CFL and LED comparison

As the economic rises day by day so the use power also rises which puts a

tremendous stress on power utilities to increase the generation of the energy so as

to meet the demand .Taking this in mind an initiative “VISION 10MW” was started

with the aim of saving 10MW of energy within 10 years pilot project a case study in

University office was initiated because here it is possible to imbibe the energy

conservation knowledge and to use the equipments at its best way with minimum

wastage. The data provided in the paper gives a detailed information regarding the

saving of energy by incorporating changes in our personal habits as well as by

using more energy efficient equipments in continuation to this in phase 2 a

detailed analysis of the Substaion is done which explained in the next sections.

4.2 Recommendations on Substaion

Recommendation is an act of technical proposal for prospective implementation

to get the yield of the energy audit by the best course of action []. Basically there is

two modes of recommendations on fiscal basis, those are, without investment and

with investment

a) Without investment:

As such in the switch yards the light fittings provided in groups, with three to

seven fittings in a group facing different directions, not yielding even output.

Instead, the analysis with the software shows if the available sodium vapour and

mercury vapour fittings are evenly placed there will be prospective improvement in

the luminous level throughout the yard. The possible arrangement is as below in

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Exiting CFL Proposed LED Light

kWh

r

Y


II-48

400 KV , 230 KV , and 110 KV switch yard. The study reveals that the control room

luminous intensity is optimum only.

Fig 4.7.Rearragement lux level in 110 KV yard

Fig 4.8 Rearrangement without investment in 230 KV switch yard


II-49

Fig 4.9 Rearrangement in 400 KV switch yard

Hence under the clause of recommendation on without investment the

rearrangement of the available lights should be placed in modified distribution form

to yield optimum result. The outcome of analysis of the existing system is shown in

the diagram, Fig 5.1 gives the rearrangement suggested in 110KV yard. On

rearranging the lights the output obtained is analyzed in VISUAL here minimum

value of lux obtained is 0.1 and maximum value obtained is 28.1 however the value

of lux is not constant that can be seen clearly from dark spots obtained in the

proposed layout similarly Fig 5.2 shows the rearrangement of 230KV switch yard ,

and Fig5.3 depicts the rearrangement of 400 KV switch yard.

b. With Investment:

1. As the sub-station yard is the special class of lighting area which is neither a

continuous process industrial area nor like a crowded public area. Hence concept

of keeping adequate lighting throughout the night hours do not serve any purpose.

By virtue of the nature of working, the’Two tier system ‘of lighting suggested

through this paper. This will be appropriate rather than keeping the required lux

level throughout the night. The advantage of the proposed scheme is manifold. The

two tier lighting system involves the stages of dim level lighting in the first stage and

standard luminous lighting in the Second level. During normal power flow occasion

it is advisable to keep yard with dim or low level lighting.


II-50

2. In the second tier of adequate luminous system adequate luminous intensity

should be made available in the yard area to carry out patrolling, execution of

unforeseen works up to certain height from the yard ground etc. Separate design

factors have been taken up for discussion.

3. In this system of lighting the height of the lighting pole should be lesser than the

height of the isolators. Hence any arc in the isolators contacts and jumper

loosening faults can be visible to the operational staff in the first tier of lighting. The

first tier of lighting poles normally suggested to erect at the corners and

recommended to operate automatically by pre set timers.

4. In the second tier of lighting is preferred with manual switching of all lights when

it needed and the system holds the illumination level as per the standards. The

second tier lighting system that the consecutive poles suggested to be erected

just 10 meters a part.

5. The concept of wrapping the pole by poly vinyl chloride is recommended with the

practical touch to the paper to avoid deterioration of poles due to soil corrosion and

increase in the rate due to the stray induction in the EHV electro magnetic

induction. The height of the lighting poles may be 10 to 12 feets above the ground

level. This recommendation will enhance the life of the lighting pole manifold also

reduction of charge carriers.

6. The merit of the two tier system as like the sub-station yard fetch considerable

cost savings and longer the life of the costly lamps.

7. Replacement of SVL into LED : According to the survey of the energy audit

team it was observed that in the sub-station ,there are three yards of 400KV,

230KV,110KV . In 400KV yard, 77 sodium vapor lamps of 250W and 19 mercury

vapor lamps of same rating are connected. In 230 KV yard, 35 sodium vapor

lamps of 250W are connected. Similarly, in 110kv yard there are 28 sodium vapor

lamps of 250W are connected. SVL and MHL are gaseous discharge lamps lesser

efficient than LEDs light So ,if the 250W of sodium vapor lamp and mercury vapor

lamps are replaced by the 60W of LEDs light , can save the more energy. The

lumens output/lamp of SVL is 27100 of 250W which will be equated by the LED

with new design.


II-51

8. The substitution of 4 feet 20 / 18 Watts LED lamp is recommended in place of 40

Watts FTL in all the 65 twin FTL provision bye passing ballasts.

a. 110KV Yard Analysis In VISUAL and cost comparison:

Fig4.10 . 110KV Tier1 lightning

Fig4.11 110KV Tier 2 lightning

1. Total no. of SVL in 110KV yards = 28 , Wattage of the one SVL = 250 W

Total Power Consumption in KW = (250 × 28) /1000 = 7KW ,

Duration of use in a year= 12×365 = 4380 hr/yr

Total power consumption in KWH = 7 × 4380 = 30660 KWH

Wattage of proposed LED light = 150 W , Total no of LED lights = 36


II-52

Total Power Consumption in KW = 150 × 36= 5.4 KW ,

Duration of use in a year= 12×365 = 4380 hr/yr

Total power consumption in KWH = 5.4 × 4380 = 23652 KWH

The difference in power of lamps = 100W

Total energy consumption = (100 × 4380 × 36) / 1000 = 15768 KWH

Saving i.e. difference in energy bill ::

Cost / Unit @ Rs.7/- (1 unit = 1 KWh) = 7 × 15768=Rs- 1,10,376 /-

Cost of the existing SVL = 4570 /- ,

Total Cost of existing lamps = (4570 × 28) = 127960/-

Cost of the proposed LED Light = 23000/- , Total Cost = 36 × 23000 = 828000/-

The additional expense to the exchequer:= 828000 – 127960 = 700040/-

Pay Back Period: =700040 / 127960 = 5 years and 6 months.

Fig. 4.12 110KV Cost Comparison

0 100000 200000 300000 400000 500000 600000 700000 800000 900000

Existing SVL(250W)

Proposed LED(150W)

In R

up

ee

s


II-53

Fig 4.13 Energy consumption

Audit Observation: : Life of SVL is approx 3 to 4 years. And life of LED of

standard brand comes around 50000 operating hours. The additional cost incurred

towards the replacement will be paid back in 5 and half year time period and eco

friendly too

b. 230KV Yard Analysis In VISUAL and cost comparison:

Fig: 4.14 ( 230 KV yard , Tier-1 )

0

5000

10000

15000

20000

25000

30000

35000

Existing SVL(250W)

Proposed LED(150W)

KW

H/Y

EAR


II-54

Fig : 4.15 . ( 230 yard, Tier.2 )

Total no. of SVL in 110KV yards = 35 , Wattage of the one SVL = 250 W

Total Power Consumption in KW = (250 × 35) /1000 = 8.75kw , Duration of use

per year= 12×365 = 4380 hr/yr

Total power consumption in KWH = 8.75 × 4380= 38325 KWH


Total Power Consumption in KW = 150 × 36= 5.4 KW , Duration of use per year=

12×365 = 4380 hr/yr


The difference in energy consumption = 100w , Total energy consumption =

(100×4380× 36)/1000 = 15768kwh

Saving i.e. difference in energy bill ::

Cost / Unit @ Rs.7/- (1 unit = 1 KWh) = 7 × 15768 =Rs- 110376 /-

Cost of the existing SVL = 4570 /-

Total Cost of existing lamps = (4570 × 35) = 159950/-



Pay Back Period: = 668050/ 110376 = 6.05 years

Audit Observation: : Life of SVL is approx 3 to 4 years. The additional cost

incurred towards the replacement will be paid back in 6.05 years time period.


II-55

Fig. 4.16 230KV Cost Analysis

Fig. 4.17 Energy Consumption

0

100000

200000

300000

400000

500000

600000

700000

800000

900000

Existing SVL(250W) Proposed LED(150W)

Pri

ce in

ru

pe

es

Cost Comparison

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

Existing SVL Proposed LED

Ene

rgy

con

sum

pti

on

in K

WH


II-56

c. 400KV Yard Analysis In VISUAL and cost comparison:

Fig4.18 230KV Tier1 lightning

Fig 4.19 230KV Tier2 lightning

Total no. of SVL & MHL in 400KV yards = 77+19= 96 , Wattage of the one SVL&

MHL = 250 W

Total Power Consumption in KW = (250 × 96) /1000 = 24kw , Duration of use per

year= 12×365 = 4380 hr/yr

Total power consumption in KWH = 24 × 4380 = 105120 KWH


Total Power Consumption in KW = 150 × 96= 14.4 KW , Duration of use per year=

12×365 = 4380 hr/yr


The difference in energy consumption = 100w

Total energy consumption = (100 × 4380 × 96) / 1000= 42048 KWH


II-57

Saving i.e. difference in energy bill :Cost / Unit @ Rs.7/- (1 unit = 1 KWh) = 7 ×

42048 =Rs- 294336 /-

Cost of the existing SVL = 4570 /- , Cost of the existing MHL = 4650 /-

Total Cost of existing lamps = (4570 × 77 +4650 × 19) = 440240/-



Pay Back Period:= 2208000 / 294336 = 7.5 years

Audit Observation: : Life of SVL is approx 3 to 4 years. The additional cost

incurred towards the replacement will be paid back in 7 and half year time period.

Fig. 4.20 400KV Cost Analysis

Fig. 4.21 400KV Energy Consumption

0

5

10

15

20

25

Existing SVL(250W) Proposed LED(150W)

Pri

ce in

lakh

s

0

20000

40000

60000

80000

100000

120000

Existing SVL Proposed LED

Ene

rgy

con

sum

pti

on

in K

WH


II-58

Fig.4.22 Saving of Energy consumption in KWH/year

The above graph shows the net energy saving in different switchyard for the

lightning system.From the graoh it is very clearly understood that a net saving of

around 69000 KWh/Year can be done on replacement of existing lights to

prescribed LED lights.

d. Control Room Analysis In VISUAL and cost comparison:

Replacement of FTL into LED: There are totally 130 FTLs (4 feet) are connected in

the control room. The present technology in the lighting system is progressive with

LED. The LED possess its merits like eco friendly due to the absence of mercury

and lesser consumption of power for the same lumen output. The lumens

output/lamp of the FTL of 40 W is approximately 1700 ,but the lumens output/lamp

of 20 W LED is also approximately1700 .So the wattage difference is

20W.Suppose the usage hours is 24 hours and number of working days is 365.The

working sheet for the simple payback period is as follows. Here the proposal will be

merely replacing the existing fluorescent tube lights and provision of same

dimension LED disabling the ballast.

0

10000

20000

30000

40000

50000

60000

70000

110KV Yard light 230KV Yard light 400KV Yard light Total Saving

Un

it C

on

sum

pti

on

in

KW

H/y

ear


II-59

Fig.4.23 control room

Total no. of FTL lights = 130 , Wattage of the one FTL= 40 W

Total Power Consumption in KW = 36 × 130=5.200 KW , Duration of use in a year=

24×365 = 8760 hr/yr

Total power consumption in KWH = 5.200 × 8760= 45,552 KWH

Wattage of proposed LED light = 20 W, Total no of LED lights = 130

Total Power Consumption in KW = 20 × 130= 2.6 KW , Duration of use in a year=

24×365 = 8760 hr/yr


The difference in energy consumption = 20 W,

Total energy consumption = (20×8760×130) /1000 =22776 KWH

Saving i.e. difference in energy bill ,

Cost / Unit @ Rs.7/- (1 unit = 1 KWh) = 7 × 22776 =Rs- 159432 /-

Cost of the existing 4 feet FTL = 50 /- , Total Cost = 50 × 130 = 6500/-

Cost of the proposed 4 feet LED Light = 900/- ,Total Cost = 130 × 900 = 1,17,000 /-

The additional expense to the exchequer: = 117000 – 6500 = Rs- 110500 /-

Pay Back Period:= 110500 / 159432= Within 9 months

Audit Observation: : Life of FTL is approx 10,000 hours but the life of the LEDs

are 5 times more than the FTL i,e 50000 hours. The additional cost incurred

towards the replacement will be paid back well within 9 months span.


II-60

fig 4.24 sub station control room with LED cost analysis

Fig 4.25 substation control room

RECOMMENDATION WITH FAN: According to the survey of the energy audit

team regarding the ceiling fans , the three ceiling fans connected in the control

room are not star rated fans. The wattage of the existing fan is 100 W. So, it is

recommended to replace the old fan into star rated fan of 50W in place of 100W

fan.

Total no. of fans in connected = 3 , Wattage of one fan = 100W

0 20000 40000 60000 80000

100000 120000 140000

Existing FTL(36W)

Proposed LED(20W)

Ru

pe

es

Cost Comparision

0 5000

10000 15000 20000 25000 30000 35000 40000 45000

Existing FTL(36W)

Proposed LED(20W)

KW

H\Y

EAR


II-61

Total Power Consumption in KW = (100× 3) /1000 = 0.3KW

Duration of use per year= 24×365 = 8760 hr/yr


Wattage of proposed star rated fan = 50 W , Total no of star rated fan = 3

Total Power Consumption in KW = 50 × 3= 0.150 KW

Duration of use per year= 24×365 = 8760 hr/yr


The difference in energy consumption = 50W

Total energy consumption = (50 × 8760 × 3) / 1000 = 1314 KWH

Saving i.e. difference in energy bill :Cost / Unit @ Rs.7/- (1 unit = 1 KWh) = 7 ×

1314 =Rs- 9198 /-

Cost of the existing fan = 700 /-

Total Cost of existing fan = (700 × 3) = 2100/-

Cost of the proposed star rated fan = 2000/-

Total Cost = 3 × 2000 = 6000/-

The additional expense to the exchequer: = 6000 – 2100 = Rs-3900/-

Pay Back Period: = 3900 / 9198 = approximately 5 months

Fig. 4.26 Control Room Fan Cost Analysis

0 1000 2000 3000 4000 5000 6000 7000

Existing fan(100 W)

Proposed fan (50W)

In R

up

ee

s


II-62

Fig. 4.27 Control Room Fan Energy Consumption

Audit Observation: : Life of FAN is approx 10,000 hours but the life of the

proposed are 5 times more than the FAN i,e 50000 hours. The additional cost

incurred towards the replacement will be paid back well within 5 months span.

0

500

1000

1500

2000

2500

3000

Existing fan(100 W)

Proposed fan (50W)

KW

H\Y

EAR


II-63

5. Design of DC Micro Grid

A microgrid is a localised groping of electricity resources and loads that normally

operates connected to and synchronous with the traditional centralised grid but

can disconnect and function autonoumously as physicall and economic condition

dictates as per the CIGRE states ( Council international des grands reseaux

electriques states) Microgrids are electricity distribution system containing loads

and distributed energy resources ( such as distributed generators storage device ,

or controllable loads) that can be operated in a controlled , coordinated way either

while connected to the main power network.

5.1 Design Calculation of micro grid with PV array and Wind mill:

The total proposed load connected in the control room is:-

Name of equipment Total Rating in KW

LED 4 feet(130 nos of each 20 watt) 2.6

Fan (3 nos of each 50 watt) 0.15

AC (1 AC of 1700 watt) ------

DC Load System 15.11

Charger Load --------

Battery --------

Total Load 18

Table 5.1 Connected load to Microgrid

All loads are operated for24 hours = 18 × 24 = 428.64 KWH\DAY

For one year = 428.64 × 365 = 156453.6KWH\year

Electricity bill @ Rs- 7 per KWH unit per year = 7 × 156453.6 = Rs-1095175.2/-

DC current are measured obtained from manual ferrule.

Actual output power of PV panel = 285 × 0.75

=213.8 WP

Power used at end = Actual power × Combined effi.


II-64

= 213.8 × 0.9 = 192.42 w

Energy produced /panel/day by PV panel = Actual power × sun ray \hr\day

= 192.42 × 6

=15588 Whr\day

No. of PV panel needed = 428000 / 15588

= 28 panels

Actual requirement is 28 panels for 8KW.

Description of each PV array

Watt/panel 285

No. of panel in series 7

No. of panel in parallel 4

Total no. of panels 28

Volts.dc 262

Amps.dc 30

KW .dc 8

Type of PV array Poly-crystalline

No. of cells in each panel 60

Table 5.2 PV Array Description

Each PV array generates 8KW using 28 panels of 285 Watts each , So here we

used 3 numbers of 8KW PV array{8*3=24KW). Hence required numbers of

panels is 28*3=84 panels

Cost of one 285w PV panel = Rs-15000/-

Total cost = 84 × 15000 = Rs-1260000/-

Payback period = 1260000 /1095175.2 = 1.15 years


II-65

Government subsidiary = 30 %

= (1260000 × 30)/100

= Rs-378000/- = 1260000-378000= 882000

Payback period after subsidiary = 882000/1095175.2 = 0.845 years

1. Size of PV array:

Size of the PV panel:-

Length= 77.01 inch

Width =39.06 inch

Time zone - UTC + 05:30, Chennai

Declinator =17.407 degree ; solar altitude =3.47 degree

2. Wind Turbine generator:

All loads are operated for24 hours = 18 × 24 = 428.64 KWH\DAY

For one year = 428.64 × 365 = 156453.6KWH\year

Electricity bill @ Rs- 7 per KWH unit = 7 × 156453.6 = Rs-1095175.2/-

Actual energy consumption = 428.64 × 365 = 156453.6 KWH

Cost of performance = 0.41

Wind speed =10m/s

Density of air = 1.225 kg/m2

Capacity factor = 0.30

No, of hour/year = 8760 hr/year

Power density of wind = 0.5 × 1.225 × 103 = 612.5 w/m

Overall losses = Cp × Trans. Loss × Generation loss= 0.4 × 0.9 × 0.9 = 0.324

Actual power density = 612.5 × 0.325 = 199 w/m2

Actual power density useful = 199 × 8760 =1743240 wh/m2 = 1743.24 kwh/m2


II-66

Rotor size = Total available energy / useful energy density = 156453.6 /1743.24 =

90 m2

Radius of rotor blade

3.14 × R2 = 90

R = (90/3.14)0.5 = 5.3 m

Power rating of turbine = Actual power × area of rotor density= 199 × 90 = 18 KW

Actual power rated of actual turbine rating = Power rating / Capacity factor

= 18 / 0.7 = 26KW

Cost of 1KW wind turbine generator = Rs-23000/-

Total cost of 26KW wind turbine generator = 26 × 23000 = Rs-598000/- = 6 lakhs

Payback period = 600000 / 1065175.2 = 0.56 years

5.2 Description of Micro grid

The Microgrid shown above Consists of PV panels and Wind mills Supplying the

whole load of the system. The designed Microgrid is a DC microgrid here the

supply from EB is taken as an optional which will supply if in case there is an error

in the system. The net supply received is sent to an intelligent block system this

block is used to provide intelligent decision to the system. Here Dc Microgrid is

proposed because the maximum load consumed is by the switch yard which

consumes a net of 15KW of DC supply. Here solar and wind is used as alternative

supply whose installation cost will be around 18.6 lacks which will be reimbursed

against the electricity bill within 3 years. Here EB supply is completely removed

and all loads are connected directly to the PV and turbine.A new DC bus system is

installed where supply from EB and Genset is used as backup source or as

compensating source in case of low output from the alternative sources.

An intelligent block of

system is also discussed in the sytem which can be used to trip the system under

fault condition. Under normal condition if the supply obtained from anyone of the

source is not enough then the intelligent block will compensate the power from

other source.


II-67

Fig 5.1 Proposed microgrid

1. In the proposed scheme taken for discussion in the project , an Direct current

micro grid has been formulated and micro wind turbine , PV panels, DG generator

all incorporated within the micro grid along with the battery set interfacing with

conventional chargers connected with AC source.

2. The purpose will be strong DC source for the protection system in the event of any

black out or brown out happening in the transmission system. The main sources

to be wind mill or solar energy.

3. In this paper, it is taken for discussion that in so called DC micro grid the analysis

of absence of one source after other and also the requirement of burden during

the operation of protection system in every possible aspects.

4. The proposal of operation of DC lighting in the control room from the DC micro grid

also taken for simulation.


II-68

5. In the 400 KV substation control room calculated with 65 twin 4 feet LED tube

lights taken for the simulation . The DC regulator also proposed to be provided for

continuous supply.

6. The wind generator discussed in this paper is a micro one which is designed for

low cut in speed and can be set in to operation even 3 to 4 m/sec velocity of wind

speed onwards.

7. The PV panels erection can be done at the top of the control room. The erection of

wind mill should be away from the normal data transmission system normally

provided on the terrace of the control room. The preventive measures like

overcharging and overvoltage should be incorporated for successful

implementation of the system primly for protection.

5.3 Case study of the proposed micro grid

Here Dc Microgrid is proposed because the maximum load consumed is by

the switch yard which consumes a net of 15KW of DC supply.

Here solar and wind is used as alternative supply whose installation cost

will be around 18.6 lacks which will be reimbursed against the electricity bill

within 3 years.

Here EB supply is completely removed and all loads are connected directly

to the PV and turbine.A new DC bus system is installed where supply from

EB and Genset is used as backup source or as compensating source in

case of low output from the alternative sources.

In sevre case such as heavy rain or flood where it is difficult to obtain

supply from EB , Solar and Wind then a bidirectional structure of supply

from gensate is provided

The Gensate supplies to the same DC bus where input from solar and wind

is provided in continuation with that a seprate bus system is also provided

which directly feeds the main load bus this will be used in case of fault.


II-69

5.4 Analysis of Microgrid system

The proposed Microgrid system is analyswd in ETAP and the report obtained is

explained in the graphical format as shown below

Fig. 5.2 Load flow report without fault in DC system


The Graph shown above gives the no of buses VS voltage , the voltage obtained

above is from solar and wind which is found to be as per the gives prescribed

value. Here variation is less then the range of +/-2 % which demonstrates that the

proposed model is perfect to take care of connectes load.

221.15 221.2

221.25 221.3

221.35 221.4

221.45 221.5

221.55 221.6

221.65

16 18 21 22 23 24 25 26 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 45 46 47 48 49 50 51 52 53 55 56 57 58

Vo

ltag

e(v

olt

s)

No. of buses

221.15

221.2

221.25

221.3

221.35

221.4

221.45

221.5

221.55

221.6

221.65

60 62 64 66 113 115 117 119 121 123 125 127 129 131 133 135 137 139 141 143 145 150

Vo

ltag

e(v

olt

s)

No. of buses


II-70

Fig 5.4 Load flow report without fault in DC system


The Graph shown above gives the no of buses VS current , the current obtained

above is from solar and wind which is found to be as per the gives prescribed

value. Here variation is less then the range of +/-2 % which demonstrates that the

proposed model is perfect to take care of connectes load.

5.5 Comparision of Existing DC system with Proposed Micro Grid

System

The proposed system of DC and Existing system of DC is compared for voltage

and current with bus numbers and the complete analysis is as shown below.

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

18 21 22 23 24 25 26 28 29 30 31 32 33 34 35 37 38 39 40 41 42 43 45 46 47 48 49 50 51 52 55 56 57 58 60 61

curr

en

t(am

ps)

No. of buses

0

0.2

0.4

0.6

0.8

1

1.2

62 64 66 113 115 117 119 121 123 125 127 129 152 132 134 136 138 140 142 144 146

Cu

rre

nt(

amp

s)

No. of buses


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Fig.5.6 Comparision of Existing and proposed


The graph shown above gives the comparision of voltage between existing and

proposed system in existing system the variation was from 219.5V to 220.5V that

means the net deviation is of +/-0.5V. In the proposed system the variation

obtained from 220.50V to 221.58V So the variation is around +/- 1.5V which is

within the given prescribed value.


217

218

219

220

221

222

16 21 23 25 28 30 32 34 36 38 40 42 45 47 49 51 53 56 58 61

Vo

ltag

e(v

olt

s)

No. of buses

Existing

Proposed

217

218

219

220

221

222

62 64 66 113 115 117 119 121 123 125 127 129 131 133 135 137 139 141 143 145 150

Vo

ltag

e(v

olt

s)

No. of buses

Existing

Proposed

0

0.2

0.4

0.6

0.8

1

1.2

18 22 24 26 29 31 33 35 38 40 42 45 47 49 51 55 57 60

Cu

rre

nt(

amp

s)

No. of buses

Existing

Proposed


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The graph shown above gives the variation of current in existing and proposed

system. The variation Obtained is found to be within the prescribed value.The

variation obtained is +/- 0.2amps.

Fig.5.10 EB per year and Cost of PV array

The graph shown above gives cost comparision of Proposed PV with the existing

EB power supply. Here it can be seen that after government subsidiary the cost is

around 8.82L which is less then EB electricity bill/year.

0

0.2

0.4

0.6

0.8

1

1.2

62 64 66 113 115 117 119 121 123 125 127 129 152 132 134 136 138 141 143 145

Cu

rre

nt(

amp

s)

No. of buses

Existing

Proposed

0

200000

400000

600000

800000

1000000

1200000

1400000

Electricity bill per year Cost of PV array After Government subsidary

Pri

ce in

ru

pe

es


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Fig.5.11 Difference in energy consumption

The above system shows the difference in energy consumotion of power grid and

proposed system. There is a net saving of 3.5KWh/year.

Fig.5.12 EB per year and cost of WTG

The graph shown above gives cost comparision of Proposed WTG with the

existing EB power supply. Here it can be seen that after government subsidiary

the cost is around 5.82L which is less then EB electricity bill/year.

16.5

17

17.5

18

18.5

19

19.5

20

20.5

Existing Power grid Proposed PV array MG

Un

it c

on

sum

pti

on

KW

/ye

ar

0

200000

400000

600000

800000

1000000

1200000

EB per year Cost of WTG

Pri

ce in

ru

pe

es


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Fig.5.13 Difference in energy consumption

The above system shows the difference in energy consumotion of power grid and

proposed system. There is a net saving of 2.5KWh/year.

16.5

17

17.5

18

18.5

19

19.5

20

20.5

Existing Power Grid Proposed Wind MG

Un

it C

osu

mp

tio

n in

KW

/ye

ar


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6. CONCLUSION

A famous quote “Energy saved is Energy generated”[10]. This shows that

apart from increasing the generation capacity with investment, one must go for the

energy audit to save the electricity at lower cost[9]. As the economic rises day by

day so the use power also rises which puts a tremendous stress on power utilities

to increase the generation of the energy so as to meet the demand .Taking this in

mind an initiative “VISION 10MW” was started with the aim of saving 10MW of

energy within 10 years and as a pilot project a case study in University office was

initiated and in next step the detailed analysis of substation was carried out along

with the establishment of new microgrid system.

In stage one of the work electrical

energy audit of the lightning system was done and new methodologies were

proposed. Here Instead of recommending all lamps to be replaced by the present

modern technology energy star rated LED lamps By these replacement, the

luminous level will be more over same with lesser involvement of cost. The system

of LED can also provided with presently available electronic control gear. Here

without investmentt includes reducing the wastage by reducing thw wastage a net

of 726 Units can be saved annually. With replacement of FTL with new modern

LED lamp a net saving of 1290 units can be saved annually. The installation cost

can be recovered within 2.5 years.

In second stage of work illumination

level analysis of of the switch yard was carried out. Here rearrangement is

proposed with the existing luminaries fixtures to achieve optimal Lux level and with

investment includes converting existing fixtures to high performance LED lamps

which gives an anual saving of 63918 units the investment can be recovered

within 4.56 years.

In third stage of work a new

system of DC Micro Grid is proposed. The DC Micro Grid proposed consists of

various alternative energy sources ranging from PV panels to Wind turbine. The

installation cost involved for setting up of MG is around 18.58 L which can be

recope against the electricity bill within 2 years.


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REFERENCES

[1] Report on “World Energy Scenarios” Composing energy futures to 2050

published in “World Energy Council 2013” pp - 1

[2] Report on “CENTRAL STATISTICS OFFICE NATIONAL STATISTICAL

ORGANISATION” published by “MINISTRY OF STATISTICS AND PROGRAMME

IMPLEMENTATION GOVERNMENT OF INDIA” website- www.mospi.gov.in pp-1

[3] Report on “Statistics at a Glance, 2012-13, Tamil Nadu Generation and

Distribution Corporation Limited, Chennai – 2” published by Tamil Nadu

Government. Pp-1 - 2

[4] Online Report published on website

“https://en.wikipedia.org/wiki/Energy_audit” by BEE pp-2

[5] Paper published on “DC Microgrids Scoping Study—Estimate of Technical and

Economic Benefits” published on March 2015 New Mexico 87185 and Livermore,

California 94550. SAND2009-135192. Pp 2-3

[6] Paper published on “http://www.innovativejournal.in/index.php” Ajcsit paper

published by M. SINGH during may 2014. Pp3-4

[7] Report published by A.K.Ahuja © Energy Audit Team, IIT Roorkee during

august 2013.pp 4-5

[8] Paper published by S. Pramanik on electrical energy audit of institutional area

in “International Journal of Advanced Research in Electrical, Electronics and

Instrumentation Engineering “ during September 2008. Pp-5-6

[9] Report published on energy audit in “Code of practice of interior illumination” –

IS 3646-1 (1992) in feb 2009. Pp 6

[10] Workbook published by Washington State University on “Energy Program via

Energy Audit “ on website “http://www.gogle.com/searchjournal.aspx”. During May

-2015. Pp-6-7

[11] V.Salehi, A.Mazloomzadeh, and O.Mohammed, “Development and

Implementation of a Phasor Measurement Unit for Real-Time Monitoring, Control

http://www.mospi.gov.in/

https://en.wikipedia.org/wiki/Energy_audit


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and Protection of Power Systems,” in IEEE Power Engg. Society .General

Meeting, Jul.24-29,2011. Pp-10-11

[12] International Journal of Engineering Research and Technology. ISSN 0974-

3154 Volume 6, Number 5 (2013), pp. 619-624 © International Research

Publication House http://www.irphouse.com. Pp - 11

[13] International Journal of Engineering and Applied Sciences

© 2012 EAAS & ARF. All rights reserved, www.eaas-journal.org. Pp- 11-12

[14] Paper published on website “http://www.ijifr.com/searchjournal.aspx” Volume -

1 Issue -4, December 2013. ID: IJIFR/V1/E4/035. Pp-15

[15] Zhenyu Huang and Jeff Dagle, SynchroPhasor Measurements: System

Architecture and Performance Evaluation in Supporting Wide-Area Applications.

PA:IEEE Power Engineering Society General Meeting 2008 .Pp-48-49

[16] “ETAP Microgrid Integrated Power System Simulation, Planning, Protection &

RealTime Microgrid Master Controller” book published on “http:// www.

Etap.com” Pp- 62

[17] Paper Published on “Smart DC Micro-grid for Effective Utilization of Solar

Energy” in “International Journal of Scientific & Engineering Research Volume 3,

Issue 12, December-2012 ISSN 2229-5518. Pp-67

http://www.irphouse.com/

http://www.eaas-journal.org/


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PAPER PUBLICATION DETAILS

“Illumination Level Study and Energy Assessment Analysis at University Office” at 2nd International Conference on Intelligent Computing and Applications (ICICA 2015) February 5 – 6th, 2016 ( SPRINGER)

design of self sustained dc microgrid through energy audit ... report/16ee10.pdf · design of self...

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