IT in Power Distribution

ENGINEERING STAFF COLLEGE OF INDIAAn Autonomous Organ of the Institution of Engineers (India)

NEED OF THE HOUR Distribution system forms the ultimate link in the

power system between the utility and end user. Customer expectations also have gone up to provide

Reliable and quality power

Timely redressal of complaints

Accurate metering and billing without errors

Facility & Flexibility of payment of bills from home

NEED OF THE HOUR

Many more in the wish list

This can be only possible if the human element at work is replaced to a good extent by automating the operations and use of Information technology becomes indispensable at this juncture

What do we need to do to meet the expectations

Replace still old, conventional, manual systems being continued in most of discoms

With the growth of network and the number of customers adopt newer technologies that provide faster service

NEED OF THE HOUR

Where human intervention is unable to cope up, adopt automation using the available & powerful IT tools

The end result should be that customers are to be provided service levels like in other sectors like banking, communications etc.

All these would improve the image of the utility

NEED OF THE HOUR

The focus areas of IT applications are Quality and reliability of supply Accurate of billing Easy payment mechanisms Better complaints handling

IT is used in energy audit,

Estimation of baseline losses &

Substation /Distribution automation

AREAS OF FOCUS

IT INITIATIVESAims at Improvement of efficiency by way of elimination

of delays, duplication, drudgery in paperwork Reduction in overall expenditure. Provides quick and efficient information systems

like on line billing, collection and on line report generation..

Very fast reconciliation between important activities of metering, billing and collection.

Web based servicing. To attain transparency and gain credibility. Customer satisfaction.

New Trends Automated Meter Reading Web Based Servicing Trouble Call Management System SCADA Consumer Analysis Tool (CAT)

IT IMPLEMENTATION INITIATIVES

IT in System Planning Load forecast is an important parameter for

system planning Requires accurate data of the system like

energy consumption for last 10 years, maximum demand

Methods of load forecast Trends: The trends for the growth in energy and

consumption are computed based on the past data are

To forecast the future demand / energy

IT IN SYSTEM PLANNING

Econometric Approach: Focuses on identification of correlation between demand and variables such as growth in GDP, population and households in the forecast

End-use Approach: Focuses on uses of electricity, takes into account specific consumption of major appliances, degree of saturation of each appliance per customer, number of customer

Using the load forecast developed using appropriate models, appropriate system planning package is to be selected for running the load flows

IT IN SYSTEM PLANNING

SCADA: Supervisory Control And Data Acquisition

It is a system that enables an electric utility to remotely monitor, coordinate and operate distribution components in a real time from remote location.

IT IN SYSTEM OPERATION

The basic components of SCADA system are Control center Controlled plant Communication system SCADA platform uses a master slave

communication principle and controls the remote end equipment through Remote Terminal Unit

IT IN SYSTEM OPERATION

RTU can perform several functions like data

acquisition, switching of circuit breakers /

capacitors, changing of taps etc. based on

the commands received from the control

centre.

IT IN SYSTEM OPERATION

In the later versions of SCADA, RTUs are

being replaced with IEDs (Intelligent

Electronic Devices), which have the

capability of measuring, monitoring, control,

protection and communicating to the local

operator or to the remote host (Ex: Numerical Relays)

IT IN SYSTEM OPERATION

We can build a Distribution Automation system

using the SCADA kernel which can accomplish many functions such as:

Substation Automation Feeder monitoring and control Load Management Automated Meter reading Trouble call management Load Survey & Energy audit and so on

IT IN SYSTEM OPERATION

Feeder Monitoring and Control Trippings and breakdowns in general and in

rural areas in particular is a matter of serious concern which causes prolonged interruptions and consumer unrest and the same can be addressed through feeder monitoring

Automation of the feeder control can be taken up using Auto reclosures near the breakers and sectionalisers in the line

IT IN SYSTEM OPERATION

Feeder Monitoring and Control For any transient fault in the line, the auto

reclosure first trips and then closes after a set time

Sectionalisers help us in isolating the fault during permanent faults and the supply can be restored for the rest of the line

IT IN SYSTEM OPERATION

Operation of SCADA requires a good Communication system for which the options available are

Public switched telephone networks Power line carrier communication Radio frequency (RF) point-to point/ point-to-

multipoint communications

IT IN SYSTEM OPERATION

Optical fibers VSAT Ethernet

Choose a judicious system considering the functionality and costs

IT IN SYSTEM OPERATION

IT in Metering System Metering technologies have evolved over a

period of time starting from electromechanical meters to static meters and later on to the smart meters

The capabilities of meters range from simple recording of energy to communication of recorded energy to either a data collecting device or a billing computer through an appropriate communication system.

Smart meters not only record energy, display the price signals given by the utility but can also run the appliances in the home as per the programme given by the user to optimise the costs.

Static (Electronic) Energy Meters The static energy meters are micro processor

based. The programmability of micro processor is useful to incorporate different features like tamper data, import-export, time-of day metering, load pattern analysis, remote meter reading.

Tamper Data: Data pertaining to tamper such as missing potential, CT polarity reversal, phase sequence reversal can be detected.

Static Energy Meters (cont.)

Time of day metering: The meters have built in real time clock to record energy usage for different times of the day in different registers in the meter.

Day is divided into different time zones, the duration of each time zone is programmable and the user can define their time zones as per their requirement. The meter records the energy consumed in each of the time zones separately and exhibits accordingly. For all HT &EHT consumers in TN & Kerala this is done.

Static Energy Meters (cont.)

Load Survey Data :The meter has the provision to store the billing and tamper data for 35 days at specified logging interval. This is useful to draw the load curves of KWH, KVAH, KVA, which gives the load pattern of the consumer

Import-export Metering: The meter can measure the energy in both directions.

MRI (Meter Reading Instrument) MRI: This is used for data transfer from/to

meter to/from the system, for analysis of data and billing.

The MRI can be preloaded with meter numbers to be read and optionally the MRI can also have a bar code reader, which will be useful to identify the s.no. of the meter.

In case of HT services with load survey data, MRI is very essential for transfer of data from meter to computer

MRI can also be used for LT energy meters.

Printer also can be attached and a bill can be generated immediately upon reading the meter.

MRI shall contain the meter sno. And the previous reading. The entire data can be off loaded at the end of the day

MRI (Meter Reading Instrument)

Telemetering Transfer of metered data through a communi-

cation network is necessary, to have constant monitoring

The meter shall be connected to a telephone line at the consumer end via a modem.

At the system end also the computer is connected to the telephone via a modem.

Whenever data is to be accessed by the computer. the consumer telephone number to be dialed and the modem connected to the telephone will connect to the meter

.

Remote Metering All 11 kv feeders with predominantly agl.

Loads, major industrial loads and selected high value consumers are equipped with data loggers, which store data, which can be retrieved locally through CMRI .

They have communication port RS232 and are read remotely through dial up modems

This helps in conducting load survey, avoid overloading of conductors and also in reduction of losses.

Cases of tampered meters or meters not recording properly and cases of pilferage can be detected.

Automatic Meter Reading

Automatic Meter Reading is a technique to transfer the Meter data / information to a remote location via suitable communication media and necessary hardware set up.

Electronic Energy Meter

Media Interface device

(Out station)

Data Communication

MediaPSTN / GSM

Media Interface Device

(In station)

Host PC at Meter Reading

Station with compatible

software

AMR uses various Communication technologies as PSTN / GSM

What is AMI

AMI stands for Advanced metering Infrastructure where not only the meter is read but many other functions such as consumer demand management is also done using suitable controller through secure and suitable two way communication

SMART METERS Smart meter is an advanced electrical

metering device that records electricity consumption at regular defined intervals, communicates with utility servers on a real time basis, provides remote connect and disconnect facilities and captures significant events ie., power outage notification, demand side management and power quality monitoring

Smart meters can also run the smart appliances as per the preset programme

Smart meters are equipped with AMI features like LAN, HAN, automatic switching, demand response as well as theft monitoring and control.

The most important features of a smart meter is a 2 way interface between the meter and utility.

This ensures the continuous monitoring and gives alerts in case the meter is subjected to any tampering

SMART METERS

AMI Process

Meter communicates with Meter Data Management System ( MDMS) on one side and the Home Area Network (HAN)

Meter Data Management System

Meter compliant to AMI ( Smart meter)

Home Area network

Zig bee communication

IT to Reduce AT&C Losses IT is an important tool to analyze the total

input into the system by collecting the meter reading data from all the boundary metering points

The billed units and billed demand are collected from the server. The collected amounts are also gathered from the server.

The difference of the collected amount against the billing demand represents the AT&C losses

ENERGY LOSSES IN THE POWER DISTRIBUTION SYSTEM

Technical Losses Commercial Losses11 kV line losses. Theft by direct tapping.Distribution transformer losses (iron and copper losses)

Theft by tampering meters, CTs and PTs.

LT line losses. Non-performing meters.Losses due to loose jumper connections.

Under-performing meters.

Short circuit and earth fault losses.

Meters not read.

Losses in service mains and energy meters.

Mistakes in billing, etc.

DETERMINATION OF TECHNICAL LOSSES ON THE 11 KV FEEDER

Technical losses on the 11 kV feeder are assessed by conducting load flow analysis of the individual 11 kV feeders including distribution transformer and LT distribution losses.

  Steady state model of the network is used to find technical losses

DETERMINATION OF TECHNICAL LOSSES ON THE 11 KV FEEDER

The loads are considered to be of constant impedance.

Load Factor of a transformer is evaluated by computing the energy input to the transformer and the peak load on the transformer and the hours for which the transformer is in service

ENERGY LOSSES IN THE POWER DISTRIBUTION SYSTEM

Loss Load Factor is computed by using the formula LLF = 0.3 (LF) + 0.7 (LF)²

Commercial losses are assessed by deducting technical losses from the total losses of the feeder, i.e. the difference between energy sent out and the energy sold.

Commercial loss in the feeder = Energy loss – Technical loss.

The following activities are undertaken to record these losses:The meter reading schedules of meter readers are revised and made coterminous with distribution transformers.The distribution transformer meter is also read and comparison is made between distribution transformer meter reading and sum total of consumption recorded in all other consumer meters coming under that distribution transformer. The difference is noted. If the losses are found to be high, action is initiated to trace the installation causing losses.

DETERMINING COMMERCIAL LOSSES

Actions Recommended for Reducing Technical Losses

Reconfiguration; Reconductoring; Employing Shunt Capacitors; Conversion from Single Circuit to Double

Circuit; Setting up of more substations; Changeover from Low Voltage Distribution

System (LVDS) to High Voltage distribution System (HVDS).

Actions Recommended for Reducing Commercial Losses

Changeover to static meters with tamper proof data and remote metering facility;

Replacing all burnt, stuck up, non-performing and underperforming meters;

Calibrating the existing meters; Flying squads and Special task force for

detection of pilferage of energy; AMR for online energy recording.

IT in Energy Accounting and Energy Audit

Energy accounting and energy audit is an important tool for the utility, which provides the means to identify the areas of leakage, wastage or inefficient use of energy

It helps in identifying measures suitable for reduction of T&D losses and can lead to significant cost and energy savings

ENERGY AUDITING IN A POWER UTILITY INVOLVES

Identifying energy losses and quantifying them;

Segregating the losses into technical and commercial losses;

Estimating the energy conservation potential of a system; and

Proposing economically viable and attractive solutions.

PROCEDURE FOR CONDUCTING AN ENERGY AUDIT

1. Gathering and collecting information in a specially designed, “Energy Systems Questionnaire” format, for the Utility under study,

2. Inter-and – intra-utility comparison of the collected data.

3. Assessment of present efficiency index for energy consumption in the utility/transformation.

4. In-depth study of utility operation, equipment and system for a general review of the energy systems to assess the operational efficiency and potential for economising.

5. Evaluation of the detailed recommendations for energy conservation,

6. Formulation of detailed action plans / strategies in consultation with plant management for implementation of the identified energy saving measures.

7. Training operating personnel in the specifics of energy conservation to enable them to implement the recommendations and also to monitor the progress on a periodic basis.

PROCEDURE FOR CONDUCTING AN ENERGY AUDIT

Successful Projects All the utilities of AP have implemented the

following IT applications, which are working satisfactorily providing better customer service

Web based applications for bill enquiry and bill payment to provide ease of payments

Centralized trouble call centre for fuse off call complaints

Spot billing using Hand held computersConsumer analysis tool to identify high risk class

of customersMonitoring and tracking system for pilferage of

energy cases.Transformer information and management system

MSEDCL implementing photo metering for metering of the LT consumers.

Photo Metering: Data entry software embedded in the digital camera. Image of the meter is uploaded to the computer which also captures the meter reading and then the bill is generated.

Photographs are processed through software and converted into an MSEDCL defined format

The company reports 40% increase in consumption after introduction of this method.

Successful Projects

It is left to your ingenuity to look for more IT applications to improve the Distribution system efficiency at large to make the power sector

A REALLY POWERFUL SECTOR

THE FINAL WORD

THANK YOU