final project report01

LABVIEW BASED THREE PHASE INDUCTION MOTOR SPEED CONTROL

CHAPTER 1

INTRODUCTION

Dept. Of Instrumentation (DYPIET)


1.1 LITERATURE SURVEY

Every engineered component has some function. A function can be

described as a transformation of inputs to outputs. For example it could be an

amplifier that accepts a signal from a sensor and amplifies it. Or, consider a

mechanical gear box with an input and output shaft. A manual transmission has an

input shaft from the motor and from the shifter. When analyzing systems we will

often use transfer functions that describe a system as a ratio of output to input.

Feedback control system block diagram figure 1 shows basic elements of a

feedback control system as represented by a block diagram. The functional

relationships between these elements are easily seen. An important factor to

remember is that the block diagram represents flow paths of control signals, but

does not represent flow of energy through the system or process. [2]

Fig no.1.1: Block diagram of feedback control

1.2 INTRODUCTION TO VIRTUAL INSTRUMENTATION

A Virtual instrumentation system is Computer software that a user would

employ to develop a Computerized Test and Measurement system.



Fig no.1.2: Block diagram of virtual instrumentation system.

The Introduction of computer in the field of instrumentation began as a

way to couple an individual instrument to computer and thus the evolution of

virtual instrumentation.[4]

DESCRIPTION:-

Signal is applied to Instrument and from instrument hardware it is connected to

computer via Bus structure.

There are mainly THREE types of buses:-

1.PC Bus.

2.VXI Bus.

3.IEEE Bus.

The computer and display are the heart of virtual instrument system. It

displays the measured reading on computer.

The Software is the Brain of the virtual instrumentation system. Software

defines the functionality of the system.[1]



1.3 What is a virtual instrument and how is it different from a

traditional instrument?

Virtual instruments are defined by the user while traditional instruments have

fixed vendor-defined functionality.

Fig 1.3 Traditional instruments (left) and software based virtual instruments (right) largely share the same architectural components, but radically different philosophies

Every virtual instrument consists of two parts – software and hardware. A virtual

instrument typically has a sticker price comparable to and many times less than a

similar traditional instrument for the current measurement task. However, the

savings compound over time, because virtual instruments are much more flexible

when changing measurement tasks.

By not using vendor-defined, prepackaged software and hardware, engineers and

scientists get maximum user-defined flexibility. A traditional instrument provides

them with all software and measurement circuitry packaged into a product with a

finite list of fixed-functionality using the instrument front panel. A virtual

instrument provides all the software and hardware needed to accomplish the



measurement or control task. In addition, with a virtual instrument, engineers and

scientists can customize the acquisition, analysis, storage, sharing, and

presentation functionality using productive, powerful software.[1]

Here are some examples of this flexibility in practice:

1. One Application Different Devices

For this particular example, an engineer is developing an application using

LabVIEW and an M Series DAQ board on a desktop computer PCI bus in his lab

to create a DC voltage and temperature measurement application. After

completing the system, he needs to deploy the application to a PXI system on the

manufacturing floor to perform the test on new product. Alternatively, he may

need the application to be portable, and so he selects NI USB DAQ products for

the task. In this example, regardless of the choice, he can use virtual

instrumentation in a single program in all three cases with no code change needed.

Fig1.4 Upgrading hardware is easy when using the same application for many devices.

2. Many Applications, One Device

Consider another engineer, who has just completed a project using her new M

Series DAQ device and quadrature encoders to measure motor position. Her next



project is to monitor and log the power drawn by the same motor. She can reuse

the same M Series DAQ device even though the task is significantly different. All

she has to do is develop the new application using virtual instrumentation

software. Additionally, both projects could be combined into a single application

and run on a single M Series DAQ device, if needed.[1]

Fig 1.5 Reduce costs by reusing hardware for many applications.

How do virtual instrumentation hardware capabilities compare

to traditional instrumentation?

An important concept of virtual instrumentation is the strategy that powers the

actual virtual instrumentation software and hardware device acceleration.

National Instruments focuses on adapting or using high-investment technologies

of companies such as Microsoft, Intel, Analog Devices, Xilinx, and others. With

software, National Instruments uses the tremendous Microsoft investment in OSs

and development tools. For hardware, National Instruments builds on the Analog

Devices investment in A/D converters.



Fundamentally, because virtual instrumentation is software-based, if you can

digitize it, you can measure it. Therefore, measurement hardware can be viewed

on two axes, resolutions (bits) and frequency. Refer to the figure below to see

how measurement capabilities of virtual instrumentation hardware compare to

traditional instrumentation. The goal for National Instruments is to push the curve

out in frequency and resolution and to innovate within the curve.[1]

Fig 1.6 Compare virtual instrumentation hardware over time to traditional

instrumentation.

Are virtual instruments and traditional instruments compatible?

Many engineers and scientists have a combination of both virtual and traditional

instruments in their labs. In addition, some traditional instruments provide a

specialized measurement which the engineer or scientist would prefer to have the

vendor define rather than actually defining it themselves. This begs the question,

“Are virtual instruments and traditional instruments compatible?”

Virtual instruments are compatible with traditional instruments almost without

exception. Virtual instrumentation software typically provides libraries for

interfacing with common ordinary instrument buses such as GPIB, serial, or



Ethernet.

In addition to providing libraries, more than 200 instrument vendors have

contributed more than 4,000 instrument drivers to National Instruments

Instrument Driver Library. Instrument drivers provide a set of high-level, human-

readable functions for interfacing with instruments. Each instrument driver is

specifically tailored to a particular model of instrument to provide an interface to

its unique capabilities.

How are virtual instruments and synthetic instruments different?

A fundamental trend in the automated test industry is a heavy shift toward

software-based test systems. For example, the United States Department of

Defense (DoD) is one of the world’s largest customers of automated test

equipment (ATE). In order to reduce the cost of ownership of test systems and

increase reuse, the DoD, through the Navy’s NxTest program, has specified that

future ATE use an architecture built on modular hardware and reconfigurable

software called synthetic instrumentation. The adoption of synthetic

instrumentation represents a significant development in the specification of future

Military ATE systems, and reflects a fundamental shift as reconfigurable software

takes center-stage in future systems. Successful implementation of software-based

test systems, such as synthetic instrumentation, requires an understanding of the

hardware platforms and software tools in the market, as well as an understanding

of the distinction between system-level architectures and instrument-level

architectures.

The Synthetic Instrument Working Group defines synthetic instruments as “a

reconfigurable system that links a series of elemental hardware and software

components with standardized interfaces to generate signals or make

measurements using numeric processing techniques”. This shares many properties



with virtual instrumentation, which is “a software-defined system, where software

based on user requirements defines the functionality of generic measurement

hardware”. Both definitions share the common properties of software-defined

instrumentation running on commercial hardware. By moving the measurement

functionality into user-accessible reconfigurable hardware, those adopting such

architectures benefit by achieving greater flexibility and reconfigurability of

systems, which in turn increases performance capabilities while reducing cost.

1.4 PC based instrumentation:-

Fig 1.7 Virtual instrumentation turns the PC into a data acquisition system

Years ago, this was feverishly setting up his first ever computer-controlled

measurement system. The machine at the heart of the instrumentation set up was

the mother of all mini computers — Digital Equipment Corporation's PDP-8 —

and one of the first desktop computers to come to India. Having linked a

Tektronix oscilloscope and a Hewlett Packard data logger, to some specially

fabricated temperature and pressure sensors, one had to mate this system to the

computer and then laboriously programme it in 8-bit machine code to analyze and

interpret the data.



Today, undergraduate students who need to make measurements for a project, use

a few sensors and transducers, a couple of multiplexing modules and rig a PC-

based instrumentation system in a couple of hours. What makes every lay user a

measurement geek, is Virtual Instrumentation (VI) — one of the most exciting

and cost effective spin offs of the personal computer. [5]

Till the 1990s, programming custom-built measurement systems was strictly for

trained professionals who worked in Basic, C++ or Pascal. Typical set ups ran

into hundreds of lines of coding and the biggest hassle was that the scientist or

expert who wanted to set up the instrumentation, needed constant hand holding by

a computer expert.

The last decade has seen the emergence of Virtual Instrument systems which

place the PC at the epicenter of the task and exploit graphical programming aids,

so that even a relative dummy can drag and drop ready-made instrument panels

which can look like the real multimeter, spectrum analyzer or waveform

generator.

Simple logic

Indeed, Nation Instruments (NI), has made LabView a synonym for the virtual

creation of measurement systems ranging from the simple digital voltage-current

meter to the most complex, multi-sensor data acquisition system.

The logic of LabView is simple: why buy 10 instruments which individually use

displays, pre-amplifiers and data converters? Why not use one such system and let

the PC do the computing? NI now supplies dozens of external measurement

modules, which can be latched to the PC. And so popular has the VI concept

become that hundreds of third-party vendors now offer modular add-ons that are

compatible with LabView's programming environment.



Other creative directions

Other companies like Data Translation and Real Time Innovations (RTI) have

taken the VI concept in other equally creative directions for the more specialist

user. RTI's Scope Tools for example, is angled at the embedded systems

developer.

Adapting VI for the Indian environment is something a few institutions in the

country are attempting. The Indian Institute of Technology, Kanpur, set up the

first Virtual Instrumentation Laboratory in the country in 1999. By 2000 it was

instrumental in publishing a model syllabus in VI for colleges all over India. In a

separate initiative, the Centre for Development of Imaging Technology (CDIT), a

Kerala Government enterprise, has collaborated with a private IT company,

Trinity Infoway, to create a CD-based Virtual Electrical Engineering Laboratory,

where 10 standard and classical experiments on DC machines and transformers

can be virtually performed on the PC, complete with variable running speed,

stunningly realistic meters and controls.

Virtual dissection

The concept has been taken even further to benefit millions of school and college

students albeit in a different direction.

Dissection of animals like frogs and rats at school level is no longer practiced in

India and even at college level; many institutions allow those who have a

conscientious objection to dissection, to go the virtual way. Amazingly realistic

software to virtually dissect a number of animals - even study human anatomy -

has been placed in the public domain.

A Google search will bring up dozens of downloadable resources like NetFrog,

Froguts, and the University of Iowa's awesomely detailed Virtual Hospital.



The message is clear: why waste time and expense on the real thing if the virtual

way goes even half way there? And that applies as much to the child learning

about the insides of an animal body, as to an engineer rigging up a complex chain

of measurement and control.[5]



CHAPTER 2

SYSTEM DESCRIPTION



2.1 BLOCK DIAGRAM OF SYSTEM:

Fig 2.1Block diagram of system

The above shown is the Block Diagram of our system. The first element is the

computer. In Computer we have NI LabVIEW software. We have to design a

program for control of speed of motor (controller used Internal PID) .This

program is Called as VI i.e virtual instrument. The control signal from PC goes to

NI USB 6009.It is data acquisition device by national instruments. Then

according to control signal i.e (voltage) frequency of VFD i.e variable frequency

drive changes. This in turn changes the speed of motor. The feedback is taken

from VFD by sensing motor parameters and this is again applied to Input of DAQ

device and thus our feedback system is completed.



2.2 Specifications of Components Used:

AC MOTORS:

PHASE: Three phase and single phase.

VOLT: 440V.

FREQUENCY: 50 HZ.

HP: 0.5 HP

KW: 0.323

FULL LOAD CURRENT: 1A

NO LOAD CURRENT: 0.3A

POLE: 4 POLE

TORQUE: 2.08 KGM

VFD:

TYPE:VSA23-03

INPUT: AC 1 Phase200-240V,5.4A,48-63Hz

OUTPUT:AC 3 Phase 0-240V,0-200Hz,3.1A

MOTOR RATINGS:0.37kW/0.5HP

MODE: V/F mode

ENCLOSURE:IP 20/UL Open type.



TRANSFORMER:

VOLT: 12V

CURRENT: 1A

TYPE: STEP DOWN

2.3 NI USB 6009:

ANALOG INPUTS: 8 analog inputs (14-bit, 48 kS/s) .

ANALOG OUTPUTS: 2 analog outputs (12-bit, 150 S/s); 12 digital I/O; 32-bit counter.

POWER SOURCE: Bus-powered for high mobility; built-in signal connectivity. [3]

Device Pinout:

NI USB-6009

Fig no.. 2.2



Analog Input:

Absolute accuracy, single-ended

Range Typical at 25 °C (mV) Maximum (0 to 55 °C) (mV)

±10 14.7 138

Absolute accuracy at full scale, differential

Range Typical at 25 °C (mV) Maximum (0 to 55 °C) (mV)

±20 14.7 138

±10 7.73 84.8

±5 4.28 58.4

±4 3.59 53.1

±2.5 2.56 45.1

±2 2.21 42.5

±1.25 1.70 38.9

±1 1.53 37.5

Number of channels............................ 8 single-ended/4 differential

Type of ADC ........................................ Successive approximation

ADC resolution (bits)

Module Differential Single-Ended

USB-6008 12 11

USB-6009 14 13



Analog Output:

Absolute accuracy (no load) ............... 7 mV typical, 36.4 mV maximum

at full scale

Number of channels............................ 2

Type of DAC ........................................ Successive approximation

DAC resolution.................................... 12 bits

Maximum update rate ........................ 150 Hz, software-timed

Output range ....................................... 0 to +5 V

Output impedance............................... 50 Ω

Output current drive............................ 5 mA

Power-on state.................................... 0 V

Slew rate............................................. 1 V/μs

Short-circuit current............................ 50 Ma

2.4TEST PANEL:



Digital I/O:

Number of channels............................ 12 total: 8 (P0.<0..7>), 4 (P1.<0..3>)

Direction control ................................. Each channel individually programmable as input or output

Output driver type

USB-6008........................................ Open-drain

USB-6009........................................ Each channel individually programmable

as push-pull or open-drain

Compatibility ....................................... CMOS, TTL, LVTTL

Internal pull-up resistor ...................... 4.7 kΩ to +5 V

Power-on state.................................... Input (high impedance)

Absolute maximum voltage range...... -0.5 to +5.8 V

Digital logic levels

Level Min Max Units

Input low voltage -0.3 0.8 V

Input high voltage 2.0 5.8 V[3]



CHAPTER 3

PID CONTROLLER



Proportional-Integral-Derivative (PID) control is the most common control

algorithm used in industry and has been universally accepted in industrial control.

The popularity of PID controllers can be attributed partly to their robust

performance in a wide range of operating conditions and partly to their functional

simplicity, which allows engineers to operate them in a simple, straightforward

manner.

As the name suggests, PID algorithm consists of three basic coefficients;

proportional, integral and derivative which are varied to get optimal response.

Closed loop systems, the theory of classical PID and the effects of tuning a closed

loop control system are discussed in this paper. The PID toolset in LabVIEW and

the ease of use of these VIs is also discussed.[5]

3.1Control System:

The basic idea behind a PID controller is to read a sensor, then compute the

desired actuator output by calculating proportional, integral, and derivative

responses and summing those three components to compute the output. Before we

start to define the parameters of a PID controller, we shall see what a closed loop

system is and some of the terminologies associated with it.

Fig3.1: Block diagram of a typical closed loop system.



3.2. Definition of Terminologies:-

The control design process begins by defining the performance requirements.

Control system performance is often measured by applying a step function as the

set point command variable, and then measuring the response of the process

variable. Commonly, the response is quantified by measuring defined waveform

characteristics. Rise Time is the amount of time the system takes to go from 10%

to 90% of the steady-state, or final, value. Percent Overshoot is the amount that

the process variable overshoots the final value, expressed as a percentage of the

final value. Settling time is the time required for the process variable to settle to

within a certain percentage (commonly 5%) of the final value. Steady-State Error

is the final difference between the process variable and set point. Note that the

exact definition of these quantities will vary in industry and academia.

Fig 3.2: Response of a typical PID closed loop system.

After using one or all of these quantities to define the performance requirements

for a control system, it is useful to define the worst case conditions in which the

control system will be expected to meet these design requirements. Often times,

there is a disturbance in the system that affects the process variable or the

measurement of the process variable. It is important to design a control system



that performs satisfactorily during worst case conditions. The measure of how

well the control system is able to overcome the effects of disturbances is referred

to as the disturbance rejection of the control system.

In some cases, the response of the system to a given control output may change

over time or in relation to some variable. A nonlinear system is a system in which

the control parameters that produce a desired response at one operating point

might not produce a satisfactory response at another operating point. For instance,

a chamber partially filled with fluid will exhibit a much faster response to heater

output when nearly empty than it will when nearly full of fluid. The measure of

how well the control system will tolerate disturbances and nonlinearities is

referred to as the robustness of the control system.

Some systems exhibit an undesirable behavior called deadtime. Deadtime is a

delay between when a process variable changes, and when that change can be

observed. For instance, if a temperature sensor is placed far away from a cold

water fluid inlet valve, it will not measure a change in temperature immediately if

the valve is opened or closed. Dead time can also be caused by a system or output

actuator that is slow to respond to the control command, for instance, a valve that

is slow to open or close. A common source of dead time in chemical plants is the

delay caused by the flow of fluid through pipes.

Loop cycle is also an important parameter of a closed loop system. The interval of

time between calls to a control algorithm is the loop cycle time. Systems that

change quickly or have complex behavior require faster control loop rates.



Fig 3.3: Response of a closed loop system with deadtime.

Once the performance requirements have been specified, it is time to examine the

system and select an appropriate control scheme. In the vast majority of

applications, a PID control will provide the required results.[5]

3.3 PID Responses:

1. Proportional Response

The proportional component depends only on the difference between the set

point and the process variable. This difference is referred to as the Error term.

The proportional gain (Kc) determines the ratio of output response to the error

signal. For instance, if the error term has a magnitude of 10, a proportional

gain of 5 would produce a proportional response of 50. In general, increasing

the proportional gain will increase the speed of the control system response.

However, if the proportional gain is too large, the process variable will begin

to oscillate. If Kc is increased further, the oscillations will become larger and

the system will become unstable and may even oscillate out of control.



Fig 3.4: Block diagram of a basic PID control algorithm.

2. Integral Response

The integral component sums the error term over time. The result is that even a

small error term will cause the integral component to increase slowly. The

integral response will continually increase over time unless the error is zero, so

the effect is to drive the Steady-State error to zero. Steady-State error is the final

difference between the process variable and set point. A phenomenon called

integral windup results when integral action saturates a controller without the

controller driving the error signal toward zero.

3. Derivative Response

The derivative component causes the output to decrease if the process variable is

increasing rapidly. The derivative response is proportional to the rate of change of

the process variable. Increasing the derivative time (Td) parameter will cause the

control system to react more strongly to changes in the error term and will

increase the speed of the overall control system response. Most practical control

systems use very small derivative time (Td), because the Derivative Response is

highly sensitive to noise in the process variable signal. If the sensor feedback



signal is noisy or if the control loop rate is too slow, the derivative response can

make the control system unstable

3.4TUNNING:-

The process of setting the optimal gains for P, I and D to get an ideal response

from a control system is called tuning. There are different methods of tuning of

which the “guess and check” method and the Ziegler Nichols method will be

discussed.

The gains of a PID controller can be obtained by trial and error method. Once an

engineer understands the significance of each gain parameter, this method

becomes relatively easy. In this method, the I and D terms are set to zero first and

the proportional gain is increased until the output of the loop oscillates. As one

increases the proportional gain, the system becomes faster, but care must be taken

not make the system unstable. Once P has been set to obtain a desired fast

response, the integral term is increased to stop the oscillations. The integral term

reduces the steady state error, but increases overshoot. Some amount of overshoot

is always necessary for a fast system so that it could respond to changes

immediately. The integral term is tweaked to achieve a minimal steady state error.

Once the P and I have been set to get the desired fast control system with minimal

steady state error, the derivative term is increased until the loop is acceptably

quick to its set point. Increasing derivative term decreases overshoot and yields

higher gain with stability but would cause the system to be highly sensitive to

noise. Often times, engineers need to tradeoff one characteristic of a control

system for another to better meet their requirements.

The Ziegler-Nichols method is another popular method of tuning a PID

controller. It is very similar to the trial and error method wherein I and D are set

to zero and P is increased until the loop starts to oscillate. Once oscillation starts,



the critical gain Kc and the period of oscillations Pc are noted. The P, I and D are

then adjusted as per the tabular column shown below.

Control P Ti Td

P 0.5Kc - -

PI 0.45Kc Pc/1.2 -

PID 0.60Kc 0.5Pc Pc/8

Table 3.5:- Ziegler-Nichols tuning, using the oscillation method.

3.5 NI LABVIEW AND PID:

LabVIEW PID toolset features a wide array of VIs that greatly help in the design

of a PID based control system. Control output range limiting, integrator anti-

windup and bumpless controller output for PID gain changes are some of the

salient features of the PID VI. The PID Advanced VI includes all the features of

the PID VI along with non-linear integral action, two degree of freedom control

and error-squared control.

Fig 3.6.1: VIs from the PID controls palette of LabVIEW

PID palette also features some advanced VIs like the PID Autotuning VI and the

PID Gain Schedule VI. The PID Autotuning VI helps in refining the PID

parameters of a control system. Once an educated guess about the values of P, I

and D have been made, the PID Autotuning VI helps in refining the PID

parameters to obtain better response from the control system.[3]



Fig 3.6.2: Advanced VIs from the PID controls palette of LabVIEW

The reliability of the controls system is greatly improved by using the LabVIEW

Real Time module running on a real time target. National Instruments provides

the new M Series Data Acquisition boards which provide higher accuracy and

better performance than an average control system.

3.6 Variable Frequency Drive:

what is a VFD?

You can divide the world of electronic motor drives into two categories: AC and

DC. A motor drive controls the speed, torque, direction and resulting horsepower

of a motor. A DC drive typically controls a shunt wound DC motor, which has

separate armature and field circuits. AC drives control AC induction motors, and-

like their DC counterparts-control speed, torque, and horsepower.

Application as an Example:

Let's take a brief look at a drive application. In Fig. 1, you can see a simple

application with a fixed speed fan using a motor starter. You could replace the 3-

phase motor starter with Variable Frequency Drive (VFD) to operate the fan at

variable speed. Since you can operate the fan at any speed below its maximum,

you can vary airflow by controlling the motor speed instead of the air outlet

damper.[5]



Fig3.7, Fixed Speed Fan Application

A drive can control two main elements of a 3-phase induction motor: speed and

torque. To understand how a drive controls these two elements, we will take a

short review of AC induction motors. Fig. 2 shows the construction of an

induction motor. The two basic parts of the motor, the rotor and stator, work

through magnetic interaction. A motor contains pole pairs. These are iron pieces

in the stator, wound in a specific pattern to provide a north to south magnetic

field.[5]

Figure 3.8, Basic Induction Motor Construction



Fig 3.9 Operating Principles of Induction Motor

With one pole pair isolated in a motor, the rotor (shaft) rotates at a specific speed:

the base speed. The number of poles and the frequency applied determine this

speed (Fig. 4). This formula includes an effect called "slip." Slip is the difference

between the rotor speed and the rotating magnetic field in the stator. When a

magnetic field passes through the conductors of the rotor, the rotor takes on

magnetic fields of its own. These rotor magnetic fields will try to catch up to the

rotating fields of the stator. However, it never does -- this difference is slip. Think

of slip as the distance between the greyhounds and the hare they are chasing

around the track. As long as they don't catch up to the hare, they will continue to

revolve around the track. Slip is what allows a motor to turn.[5]

Motor Slip:

Shaft Speed =120 X F

P- Slip

Slip for NEMA B Motor = 3 to 5% of Base Speed which is



1800 RPM at Full Load

F = Frequency applied to the motor

P = Number of motor poles

Example:

Shaft Speed =120 X60Hz

4- Slip

Induction Motor Slip Calculation

We can conveniently adjust the speed of a motor by changing the frequency

applied to the motor. You could adjust motor speed by adjusting the number of

poles, but this is a physical change to the motor. It would require rewinding, and

result in a step change to the speed. So, for convenience, cost-efficiency, and

precision, we change the frequency. Fig. 5 shows the torque-developing

characteristic of every motor: the Volts per Hertz ratio (V/Hz). We change this

ratio to change motor torque. An induction motor connected to a 460V, 60 Hz

source has a ratio of 7.67. As long as this ratio stays in proportion, the motor will

develop rated torque. A drive provides many different frequency outputs. At any

given frequency output of the drive, you get a new torque curve.

3.7 How Drive Changes Motor Speed:

Just how does a drive provide the frequency and voltage output necessary to

change the speed of a motor? That's what we'll look at next. All PWM drives

contain these main parts, with subtle differences in hardware and software

components. Although some drives accept single-phase input power, we'll focus

on the 3-phase drive. But to simplify illustrations, the waveforms in the following

drive figures show only one phase of input and output.



The input section of the drive is the converter. It contains six diodes, arranged in

an electrical bridge. These diodes convert AC power to DC power. The next

section-the DC bus section-sees a fixed DC voltage.

The DC Bus section filters and smoothens out the waveform. The diodes actually

reconstruct the negative halves of the waveform onto the positive half. In a 460V

unit, you'd measure an average DC bus voltage of about 650V to 680V. You can

calculate this as line voltage times 1.414. The inductor (L) and the capacitor (C)

works together to filter out any AC component of the DC waveform. The

smoother the DC waveform, the cleaner the output waveform from the drive.

The DC bus feeds the final section of the drive: the inverter. As the name implies,

this section inverts the DC voltage back to AC. But, it does so in a variable

voltage and frequency output. How does it do this? That depends on what kind of

power devices your drive uses. If you have many SCR (Silicon Controlled

Rectifier)-based drives in your facility, see the Sidebar. Bipolar Transistor

technology began superceding SCRs in drives in the mid-1970s. In the early

1990s, those gave way to using Insulated Gate Bipolar Transistor (IGBT)

technology, which will form the basis for our discussion.

Switching Bus With IGBTs

Today's inverters use Insulated Gate Bipolar Transistors (IGBTs) to switch the

DC bus on and off at specific intervals. In doing so, the inverter actually creates a

variable AC voltage and frequency output. As shown in Fig. 7, the output of the

drive doesn't provide an exact replica of the AC input sine waveform. Instead, it

provides voltage pulses that are at a constant magnitude.


http://www.joliettech.com/igbt-insulated_gate_bipolar_transistors.htm


Fig 3.9.1 Drive Output Waveform

The drive's control board signals the power device's control circuits to turn "on"

the waveform positive half or negative half of the power device. This alternating

of positive and negative switches recreates the 3 phase output. The longer the

power device remains on, the higher the output voltage. The less time the power

device is on, the lower the output voltage (shown in Fig.8). Conversely, the longer

the power device is off, the lower the output frequency.

Fig 3.9.2 Drive Output Waveform Components



The speed at which power devices switch on and off is the carrier frequency, also

known as the switch frequency. The higher the switch frequency, the more

resolution each PWM pulse contains. Typical switch frequencies are 3,000 to

4,000 times per second (3 KHz to 4 KHz). (With an older, SCR-based drive,

switch frequencies are 250 to 500 times per second). As you can imagine, the

higher the switch frequency, the smoother the output waveform and the higher the

resolution. However, higher switch frequencies decrease the efficiency of the

drive because of increased heat in the power devices.[5]



CHAPTER 4

HARDWARE & SOFTWARE DETAILS OF

SYSTEM



(PART A HARDWARE)

4.1 COMPONENTS USED:

1. Personal Computer

2. Optocoupler(MCT2E)

3. ULN 2803

4. Electro-mechanical Relay

5. Transformer(12V,1A)

6. Voltage Regulator 7805

7. Diode(IN4007), Resistors, capacitors

8. Heat Sink.

4.2 POWER SUPPLY:

REGULATOR IC (7805)

It is a three pin IC used as a voltage regulator. It converts unregulated DC current

into regulated DC current.

BRIDGE RECTIFIER

A bridge rectifier makes use of four diodes in a bridge arrangement to achieve

full-wave rectification. This is a widely used configuration, both with individual

diodes wired as shown and with single component bridges where the diode bridge

is wired internally.[5]



Fig no.4.1: Connection diagram of system

4.3 OPTOCOUPLER:

There are many situations where signals and data need to be transferred from one

subsystem to another within a piece of electronics equipment, or from one piece

of equipment to another, without making a direct ohmic contact electrical

connection. Often this is because the source and destination are (or may be at

times) at very different voltage levels, like a microprocessor which is operating

from 5V DC but being used to control a triac which is switching 240V AC. In

such situations the link between the two must be an isolated one, to protect the

microprocessor from over-voltage damage.[5]



Fig no .4.2 Optocoupler

4.4 HIGH VOLTAGE HIGH CURRENT DARLINGTON

TRANSISTOR ARRAY (ULN2803):

The eight NPN Darlington connected transistors in this family of arrays are

ideally suited for interfacing between low logic level digital circuitry (such as

TTL, CMOS or PMOS/NMOS) and the higher current/voltage requirements of

lamps, relays, printer hammers or other similar loads for a broad range of

computer, industrial, and consumer applications. All devices feature open–

collector outputs and free wheeling clamp diodes for transient suppression.

The ULN2803 is designed to be compatible with standard TTL families while the

ULN2804 is optimized for 6 to 15 volt high level CMOS or PMOS



Fig.4.3 ULN 2803

4.5 RELAY:

A relay is an electrical switch that opens and closes under the control of another

electrical circuit. In the original form, the switch is operated by an electromagnet

to open or close one or many sets of contacts. It was invented by Joseph Henry in

1835. Because a relay is able to control an output circuit of higher power than the

input circuit, it can be considered to be, in a broad sense, a form of an electrical

amplifier.[5]



Fig no 4.4 Relay

Here relay is used for the isolation of various heavy appliances to the PC. Since

the PC operates on very low current, but the current in various appliances is in

Amperes therefore isolation is necessary and relay is required. Here we have used

single pole dual through relay for the purpose. [5]



(PART B SOFTWARE)

4.6 INTRODUCTION TO LABVIEW:-

Labview is basically a computer software to develope the Virtual

Instrumentation systems.

Labview(Laboratory Virtual Instrument Engg Workbench) is a graphical

programming Language that uses icons instead of lines of text to create

application.

Labview programs are called virtual instruments because their appearance

and operation imitate physical instruments.[3]

LabVIEW programs are called virtual instruments, or VIs, because their

appearance and operation imitate physical instruments, such as oscilloscopes and

multimeters. LabVIEW contains a comprehensive set of tools for acquiring,

analyzing, displaying, and storing data, as well as tools to help you troubleshoot

code you write.

In LabVIEW, you build a user interface, or front panel, with controls and indicators.

Controls are knobs, push buttons, dials, and other input mechanisms. Indicators are

graphs, LEDs, and other output displays. After you build the user interface, you add

code using VIs and structures to control the front panel objects. The block diagram

contains this code.[3]



You can use LabVIEW to communicate with hardware such as data acquisition,

vision, and motion control devices, as well as GPIB, PXI, VXI, RS232, and RS485

instruments.[2]

Fig no.4.5 Front Panel of VI system

LabVIEW (short for Laboratory Virtual Instrumentation Engineering Workbench)

is a platform and development environment for a visual programming language

from National Instruments. The graphical language is named "G". Originally

released for the Apple Macintosh in 1986, LabVIEW is commonly used for data

acquisition, instrument control, and industrial automation on a variety of

platforms including Microsoft Windows, various flavors of UNIX, Linux, and

Mac OS. The latest version of LabVIEW is version 8.6.1, released in February of

2009.[3]



4.7 Dataflow programming

The programming language used in LabVIEW, also referred to as G, is a dataflow

programming language. Execution is determined by the structure of a graphical

block diagram (the LV-source code) on which the programmer connects different

function-nodes by drawing wires. These wires propagate variables and any node

can execute as soon as all its input data become available. Since this might be the

case for multiple nodes simultaneously, G is inherently capable of parallel

execution. Multi-processing and multi-threading hardware is automatically

exploited by the built-in scheduler, which multiplexes multiple OS threads over

the nodes ready for execution.[3]

4.8 Graphical programming

LabVIEW ties the creation of user interfaces (called front panels) into the

development cycle. LabVIEW programs/subroutines are called virtual instruments

(VIs). Each VI has three components: a block diagram, a front panel, and a

connector panel. The last is used to represent the VI in the block diagrams of

other, calling VIs. Controls and indicators on the front panel allow an operator to

input data into or extract data from a running virtual instrument. However, the

front panel can also serve as a programmatic interface. Thus a virtual instrument

can either be run as a program, with the front panel serving as a user interface, or,

when dropped as a node onto the block diagram, the front panel defines the inputs

and outputs for the given node through the connector pane. This implies each VI

can be easily tested before being embedded as a subroutine into a larger program.

The graphical approach also allows non-programmers to build programs simply

by dragging and dropping virtual representations of lab equipment with which

they are already familiar. The LabVIEW programming environment, with the

included examples and the documentation, makes it simple to create small

applications. This is a benefit on one side, but there is also a certain danger of



underestimating the expertise needed for good quality "G" programming. For

complex algorithms or large-scale code, it is important that the programmer

possesses an extensive knowledge of the special LabVIEW syntax and the

topology of its memory management. The most advanced LabVIEW development

systems offer the possibility of building stand-alone applications. Furthermore, it

is possible to create distributed applications, which communicate by a

client/server scheme, and are therefore easier to implement due to the inherently

parallel nature of G-code.[3]

4.9 Benefits

One benefit of LabVIEW over other development environments is the extensive

support for accessing instrumentation hardware. Drivers and abstraction layers for

many different types of instruments and buses are included or are available for

inclusion. These present themselves as graphical nodes. The abstraction layers

offer standard software interfaces to communicate with hardware devices. The

provided driver interfaces save program development time. The sales pitch of

National Instruments is, therefore, that even people with limited coding

experience can write programs and deploy test solutions in a reduced time frame

when compared to more conventional or competing systems. A new hardware

driver topology (DAQmxBase), which consists mainly of G-coded components

with only a few register calls through NI Measurement Hardware DDK (Driver

Development Kit) functions, provides platform independent hardware access to

numerous data acquisition and instrumentation devices. The DAQmxBase driver

is available for LabVIEW on Windows, Mac OS X and Linux platforms.

In terms of performance, LabVIEW includes a compiler that produces native code

for the CPU platform. The graphical code is translated into executable machine

code by interpreting the syntax and by compilation. The LabVIEW syntax is

strictly enforced during the editing process and compiled into the executable



machine code when requested to run or upon saving. In the latter case, the

executable and the source code are merged into a single file. The executable runs

with the help of the LabVIEW run-time engine, which contains some precompiled

code to perform common tasks that are defined by the G language. The run-time

engine reduces compile time and also provides a consistent interface to various

operating systems, graphic systems, hardware components, etc. The run-time

environment makes the code portable across platforms. Generally, LV code can

be slower than equivalent compiled C code, although the differences often lie

more with program optimization than inherent execution speed.

Many libraries with a large number of functions for data acquisition, signal

generation, mathematics, statistics, signal conditioning, analysis, etc., along with

numerous graphical interface elements are provided in several LabVIEW package

options. The number of advanced mathematic blocks for functions such as

integration, filters, and other specialized capabilities usually associated with data

capture from hardware sensors is immense. In addition, LabVIEW includes a text-

based programming component called MathScript with additional functionality

for signal processing, analysis and mathematics. MathScript can be integrated

with graphical programming using "script nodes" and uses .m file script syntax

that is generally compatible with Matlab.

The fully object-oriented character of LabVIEW code allows code reuse without

modifications: as long as the data types of input and output are consistent, two sub

VIs are interchangeable.

The LabVIEW Professional Development System allows creating stand-alone

executables and the resultant executable can be distributed an unlimited number

of times. The run-time engine and its libraries can be provided freely along with

the executable.


http://en.wikipedia.org/wiki/Matlab


A benefit of the LabVIEW environment is the platform independent nature of the

G code, which is (with the exception of a few platform-specific functions)

portable between the different LabVIEW systems for different operating systems

(Windows, Mac OS X and Linux). National Instruments is increasingly focusing

on the capability of deploying LabVIEW code onto an increasing number of

targets including devices like Phar Lap OS based LabVIEW real-time controllers,

PocketPCs, PDAs, FieldPoint modules and into FPGAs on special boards.

There is a low cost LabVIEW Student Edition aimed at educational institutions

for learning purposes. There is also an active community of LabVIEW users who

communicate through several e-mail groups and Internet forums.

Criticism

LabVIEW is a proprietary product of National Instruments. Unlike common

programming languages such as C or FORTRAN, LabVIEW is not managed or

specified by a third party standards committee such as ANSI.

In addition, as of version 8, all LabVIEW installations on Windows computers

require customers to contact National Instruments by Internet or phone to

"activate" the product. Macintosh users are not subject to this requirement. The

increasing dependence on the vendor suggests a possible threat to privacy and

data security. For example, although National Instruments claims the process is

"secure and anonymous" the immediate implication is that a legal but privately

installed instance of LabVIEW seems no longer possible.

Building a stand-alone application with LabVIEW requires the Application

Builder component which is included with the Professional Development System

but requires a separate purchase if using the Base Package or Full Development

System. Compiled executables produced by the Application Builder are not truly

standalone in that they also require that the LabVIEW run-time engine be


http://en.wikipedia.org/w/index.php?title=FieldPoint&action=edit&redlink=1


installed on any target computer on which users run the application.[3] The use of

standard controls requires a runtime library for any language and all major

operating system suppliers supply the required libraries for common languages

such as 'C'. However, the runtime required for LabVIEW is not supplied with any

operating system and is required to be specifically installed by the administrator

or user. This requirement can cause problems if an application is distributed to a

user who may be prepared to run the application but does not have the inclination

or permission to install additional files on the host system prior to running the

executable.

There is some debate as to whether LabVIEW is really a general purpose

programming language (or in some cases whether it is really a programming

language at all) as opposed to an application-specific development environment

for measurement and automation.[4] Critics point to a lack of features, common in

most other programming languages, such as native recursion and, until version

8.20, object oriented features.

Also, for a environment heavily targeted for test, LabVIEW includes no built-in

functions for formally testing limits, reading a limits file, and conveniently

tracking the passing or failing results. Companies tend to build their own

proprietary functions for this basic feature if they choose not to use TestStand.

Simplifying the development process:-

Virtual instrumentation has led to a simpler way of looking at measurement

systems. Instead of using several stand-alone instruments for multiple

measurement types and performing rudimentary analysis by hand, engineers now

can quickly and cost-effectively create a system equipped with analysis software

and a single measurement device that has the capabilities of a multitude of

instruments.


http://en.wikipedia.org/wiki/LabVIEW#cite_note-3%23cite_note-3

http://en.wikipedia.org/wiki/LabVIEW#cite_note-Using_the_LabVIEW_Run-Time_Engine-2%23cite_note-Using_the_LabVIEW_Run-Time_Engine-2


Powerful off-the-shelf software, such as our own company's LabVIEW,

automates the entire process, delivering an easy way to acquire, analyse, and

present data from a personal computer without sacrificing performance or

functionality. The software integrates tightly with hardware, making it easy to

automate measurements and control, while taking advantage of the personal

computer for processing, display, and networking capabilities.

The expectations of performance and flexibility in measurement and control

applications continue to rise in the industry, growing the importance of software

design. By investing in intuitive engineering software tools that run at best

possible performance, companies can dramatically reduce development time and

increase individual productivity, giving themselves a powerful weapon to wield in

competitive situations.

Preparing investments for the future

Measurement systems have historically been 'islands of automation', in which you

design a system to meet the needs of a specific application. With virtual

instrumentation, modular hardware components and open engineering software

make it easy to adapt a single system to a variety of measurement requirements.

To meet the changing needs of your testing system, open platforms such as PXI

(PCI extensions for Instrumentation) make it simple to integrate measurement

devices from different vendors into a single system that is easy to modify or

expand, as new technologies emerge or your application needs change. With a

PXI system, you can quickly integrate common measurements such as machine

vision, motion control, and data acquisition to create multifunction systems

without spending valuable engineering hours making the hardware work together.

The open PXI platform combines industry-standard technologies, such as

CompactPCI and Windows operating systems, with built-in triggering to provide

a rugged, more deterministic system than desktop PCs.



BeyondPC

The internet has ushered in a new age of data sharing, and has spurred new

networking and remote computing capabilities of virtual instrumentation that was

simply not possible with their stand-alone propriety counterparts. Virtual

instrumentation takes advantage of the internet, so you can easily publish data to

the web direct from the measurement control device, and read data on a handheld

personal digital assistant, or even on a cellular phone.

This level of connectivity will progress even further, bringing a new meaning to

modularity. With advances in internet and wireless technologies, engineers will be

able to reuse modular components, and also more easily share their knowledge

and experiences across global enterprises - consolidating engineering efforts

across every stage of development.

The wave of commercial technology advances will continue. The performance

advances will be easier to implement, saving valuable development time and

integration time while reducing costs over traditional instrumentation solutions.

No one can predict exactly where the future will take virtual instrumentation,

but one thing is clear - the PC and its related technologies will be at the centre,

and you will be more successful as a result.[3]

4.9.1 FEATURES:-

Productive Software (Real Time)

National Instruments increases the productivity of engineers

and scientists in developing test, control, and design systems by providing

software products for a wide range of functionality. NI LabVIEW is the graphical

development environment for creating flexible and scalable test, measurement,

and control applications rapidly and at minimal cost. With LabVIEW, engineers



and scientists interface with real-world signals, analyze data for meaningful

information, and share results and applications. Intuitive block diagrams in NI

LabVIEW make it easy to develop custom applications while taking advantage of

the PC for processing, display, and device connectivity.

Modular Hardware

By integrating commercially available silicon and bus technologies with

innovative designs, NI data acquisition (DAQ) products continue to improve

measurement speed and accuracy while reducing costs for engineers and

scientists. NI multifunction DAQ devices are available on the most widely used

buses, including PCI, PCI Express, PXI, IEEE 1394 (FireWire), and USB, and

work with the industry's most popular operating systems such as Windows, Linux,

and Mac OS X.

For measurements that require higher performance, resolution, or speeds,

engineers use NI modular instruments, which combine stand-alone instrument

quality and measurement capabilities with the flexibility and scalability of NI data

acquisition products, to offer integrated timing and synchronization resources, as

well as the latest commercial technologies such as ADCs, DACs, FPGAs, and PC

buses. Using NI modular instruments with powerful NI LabVIEW software, test

and design engineers can create user-defined measurement systems that deliver

greater flexibility, accuracy, throughput, and synchronization .[3]



4.9.2 IMPLEMENTING VI SYSTEMS USING LABVIEW:

FRONT PANEL:-

Fig no. 4.6: Front panel of VI system

Adding a Control to the Front Panel:-

1.Controls on the front panel simulate the input mechanisms on a physical

instrument and supply data to the block diagram of the VI. Many physical

instruments have knobs you can turn to change an input value

Fig no. 4.7: Control palette of VI system



2. If you are a new LabVIEW user, the Controls palette opens with the Express

subpalette visible by default. If you do not see the Express subpalette, click

Express on the Controls palette to display the Express subpalette.

3. Move the cursor over the icons on the Express subpalette to locate the Numeric

Controls palette.

When you move the cursor over icons on the Controls palette, the name of the

subpalette, control, or indicator appears in a tip strip below the icon.[5]

Fig no.4.8 Function palette of VI system

4. Click the Numeric Controls icon to display the Numeric Controls palette.

5. Click the knob control on the Numeric Controls palette to attach the control to the

cursor, then place the knob on the front panel to the left of the waveform graph.[2]

Wiring Objects on the Block Diagram:-

1. On the block diagram, move the cursor over the Knob terminal, shown at left.

The cursor becomes an arrow, or the Positioning tool, shown at left. Use the

Positioning tool to select, position, and resize objects.

2. Use the Positioning tool to select the Knob terminal and make sure it is to the left



of the Simulate Signal Express VI and inside the gray loop, shown at left.

The terminals inside the loop are representations of front panel controls and

indicators. Terminals are entry and exit ports that exchange information between

the front panel and block diagram.

3. Deselect the Knob terminal by clicking a blank space on the block diagram. If

you want to use a different tool with an object, you must deselect the object to

switch the tool.

4. Move the cursor over the arrow on the Knob terminal, shown at left. The cursor

becomes a wire spool, or the Wiring tool, shown at left. Use the Wiring tool to wire

objects together on the block diagram. [5]

Fig no 4.9 Block diagram VI system

5. When the Wiring tool appears, click the arrow on the Knob terminal and then

click the arrow on the Amplitude input of the Simulate Signal Express VI, shown at

left, to wire the two objects together.

A wire appears and connects the two objects. Data flows along this wire from the

Knob terminal to the Express VI.



6. Select File»Save to save the VI. [2]

Changing a Signal Type:-

The block diagram has a blue icon labeled Simulate Signal. This icon represents the

Simulate Signal Express VI. The Simulate Signal Express VI simulates a sine wave

by default.

1. Display the block diagram by pressing the <Ctrl-E> keys or by clicking the block

diagram. Locate the Simulate Signal Express VI, shown at left. An Express VI is a

component of the block diagram that you can configure to perform common

measurement tasks. The Simulate Signal Express VI simulates a signal based on the

configuration that you specify.

2. Right-click the Simulate Signal Express VI and select Properties from the

shortcut menu to display the Configure Simulate Signal dialog box. (Mac OS) Press

<Command>-click to perform the same action as right-click.

You also can double-click the Express VI to display the Configure Simulate Signal

dialog box. If you wire data to an Express VI and run it, the Express VI displays

real data in the configuration dialog box. If you close and reopen the Express VI,

the VI displays sample data in the configuration dialog box until you run the VI

again[2].

3. Select Sawtooth from the Signal type pull-down menu. The waveform on the

graph in the Result Preview section changes to a sawtooth wave.



Types of Graphs :-

LabVIEW includes the following types of graphs and charts: Waveform Graphs

and Charts—Display data typically acquired at a constant rate. XY Graphs—

Display data acquired at a non-constant rate and data for multivalued functions.

Intensity Graphs and Charts—Display 3D data on a 2D plot by using color to

display the values of the third dimension. Digital Waveform Graphs—Display data

as pulses or groups of digital lines. (Windows) 3D Graphs—Display 3D data on a

3D plot in an ActiveX .[2]

3D Graphs:-

A Surface plot uses x,y and z data to plot points on graph. The surface plot then

connects these points, forming a three dimensional surface view of data. For

example you could use a surface plot for terrain mapping. The following figure

shows 3D surface graph and 3D parametric surface graph.

Fig no. 4.10: 3D graph

The 3D graphs use ActiveX technology and VIs that handle 3D representation.



When you select a 3D graph LabVIEW places an ActiveX container on the front

panel that contains a 3D graph control. LabVIEW also places a reference to the

3D graph control on the block diagram. LabVIEW wires this reference to one of

the three 3D Graph VIs.[3]



CHAPTER 5

OPERATIONAL DETAILS

5.1PROCEDURE:-



1. Switch ON the computer.

2. Open the LabVIEW 8.6 software.

3. Then go to File menu and open the VI i.e. virtual instrument for speed

control.

4. Connect the DAQ NI USB 6009 to PC.

5. Switch ON the power supply for VFD.

6. Do the connection between VFD and NI USB 6009.

7. Do the connection between VFD and Three phase induction motor.

8. Then Run the VI.

9. After that motor shaft will start rotating irregularly.

10. Then Tune the internal PID in LabVIEW.

11. Give the desired set point.

12. Now, the motor speed is controlled to desired set point.

13. See the graph for PID response.

14. See the result in which process variable is achieving set point.

15. Now stop the VI.

16. Disconnect DAQ card from VFD.

17. Disconnect connection between VFD and motor.

18. Switch off the supply of VFD.

19. Then turn off the computer.



20. Switch off computer supply.

EXPLORING THE APPLICATIONS

1. Data Acquisition.

2. Instrument control.

3. Automation Test.

4. Signal processing & Analysis.

5. Embedded Design.

6. Process control.

7. Dynamic simulation.[5]

5.2 REAL TIME APPLICATION AREAS:-

Test and Validation:-

1. Integrated test and control

2. Destructive testing

3. Endurance testing

4. Autonomous operation

5.3 Industrial Control

1. Process Control

2. Environmental control

3. Predictive maintenance



4. Industrial inspection

5.4 Control Design

1. Rapid control prototyping

2. Hardware in the loop testing

3. Model based design.

5.5 INDUSTRIAL APPLICATION:

1. Stable Control of Water Supply.

2. In Steel Plant For Controlling the speed of conveyor to keep the good

quality of steel.[5]



CHAPTER 6

RESULT AND ANALYSIS



Fig no.6.1 Front Panel of VI



Fig no.6.2 Block Diagram of VI for Closed loop Control.



Fig no.6.3 Block Diagram of VI for Manual Control.



Fig no.6.4 Result with PID Response.



CONCLUSION

We Used LABVIEW for Controlling Parameters like Speed and Direction of

motor Using Inbuilt PID, DAQ, VFD and other Mathematical modules.

The greatest learning experience in this project comes from the design and

construction of LabVIEW based Graphical Programming and the real

implementation of embedded system, Electro-mechanical relays and Opto-couper,

ULN 2803.

During the development of our project we studied and analyzed many real world

applications of Electronics and Software Engineering. Some of the theoretical

knowledge that was inculcated in us within our engineering program, which we

have applied practically.

We developed LABVIEW based Experimental trainer for controlling the speed of

Three Phase Induction Motor successfully.



BILLS OF MATERIAL

SR NO. EQUIPMENT QTN Approx. cost

1 Three Phase Induction Motor. 1 1,000/-

2 Single Phase Induction Motor 1 5,00/-

3 VFD 1 9,000/-

4 Driver Circuit For VFD 1 1,500/-

5 Fabrication Work 1 500/-

TOTAL 12,500/-



BIBLIOGRAPHY

[1] Darren kwock and Coombs ,Electronic Instrumentation

Handbook , 1999,3rd edition, McGraw-Hill.

[2] Bela G Liptak ,Process Control ,volume 2,3rd edition,

Chilton Book company.

[3] Lab view 8.6 Manuals,NI publications.

[4] Shenvi,Electronic Instrument and Product

Design,4thedition,ctc publications.

[5] Internet, www.ni.com,www.wikipedia.com.



Appendix


final project report01

Documents