Problem Forming Of Peripheral Computer Science Essay

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Symmetrical components are mainly used in the analysis of unsymmetrical fault in the power system. The unsymmetrical faults are mostly occurred on transmission line, generator and transformer which are developed fault current and fault voltage in unbalance. A symmetrical component is widely used in protection of power system components.

( Two digital filtering algorithms for fast estimation of symmetricacomponents in a power system: a static estimation approach). Protection of power system is required exactly identification of symmetrical components of the measured signals. During unbalanced condition, symmetrical components would be changed their values significantly. It was very important to track symmetrical components. The unbalanced currents and voltages are resolved into symmetrical components through positive, negative and zero sequence components. In unbalance, the voltage and current can be measured using static state estimation and dynamic state estimation.

symmetrical components is supported for distance relaying which is calculated by Fourier filers with a short data window giving sufficient voltage and current filtration according to the fault type.

Symmetrical components was introduced in 1918.Unsymmetrical three-phase voltages and currents into three sets of Symmetrical component They are divided three basic components such as positive sequences, negative sequences and zero sequences .The protection method is used certain relations between voltages and currents in a three-phase post-fault power system. The phase voltages and currents are transformed into symmetrical components using by Fourier filters. Initially this transformation method was developed for the manual calculation of fault current and fault voltage using with numerical methods and digital computer then several packages are utilize to transformation of symmetrical components for unbalance fault current estimation.

In transmission line fault may be occurred due to lighting, storm, switch surges, failure insulator and others reason hence the unsymmetrical fault would be developed on transmission line. The unsymmetrical fault can be divided such as line-ground, line-line-ground and line-line.

The line to line fault may be occurred when two Line conductors are in contact with each other.

A single line to ground fault may be occurred between a line conductor and neutral conductor or ground conductor in three phase grounded neutral systems.

Two line to ground fault may be occurred two phase conductors are in contact with the neutral or ground conductor.

During the unsymmetrical condition the negative sequences would be available. When neutral or ground is involved at the fault the zero sequences would be available. During the symmetrical condition the positive sequences would be available including three phase faults.

During the symmetrical condition the symmetrical components has fixed values and positive sequence voltage would be equal to peak line-earth voltage of the a- phase meanwhile negative sequences and zero sequences may be zero but during the fault occurs on symmetrical components these value must be verified.

In this project carried out used by MATLAB software and printed circuit board (PCB) hardware. PCB is measured the voltage and current during the supply which is connected to load. PCB is designed and simulated of Printed Circuit Board using different software packages like ISIS and ARES. In electronics, PCB's are mainly used to provide mechanical support and to connect electronic components electrically by using conductive paths or traces, etched from a copper laminated sheet onto a non-conductive substrate.

Next MATLAB no need give whether voltage or current, the signal is given as a input. The MATLAB simulink simulation tool is provided to calculated faults such as line-ground fault, line-line fault, and line-line-ground fault in the power transmission line. The fault current and fault voltage are calculated with symmetrical components at the fault point which are given both per unit and in real values. The simulation wave form would be observed through the scope. The value of voltage and current are obtained from the scope. The relaying process is not within the scope. The relaying process means trip decision, fault location and fault classification.

PCB, MATLAB

BACKGROUND OF PROJECT

The symmetrical component is mostly applied in transmission line of power system. According to theory the unbalance current and voltage in the transmission line, can be resolved into the three set of symmetrical sequences such as positive sequence, negative sequence and zero sequence. The balance current are known respectively as positive, negative and zero sequence components during the unbalance condition the negative sequence and zero sequence are present. The positive sequence is present in symmetrical condition. The protection relay is used to detect unsymmetrical condition in three phase power system. Negative sequence is important to detect a symmetrical condition. In this project the Fourier filtering is used to estimate the unsymmetrical voltage and current this is this method.

There are many estimation methods for determine to symmetrical components, the Fourier filtering is used to calculated the time of at least one period at one cycle.

The reference a(x) present kalman filtering method which can be provide to extract symmetrical components during the unbalanced in three phase system but magnitude and phase angle are verified with the system. The sampling frequency is involved with the estimated parameters. The estimated parameter is time verified within the window size but the range of variation was small. This estimation method also can be determined harmonics which is to be able to calculate their symmetrical components.

The reference (a fast method for identification of sy.com) present the symmetrical components of unsymmetrical wave form are measured using by a new dynamic technique. This technique is used based on stochastic estimation theory. The algorithm is used to test the simulation data. The algorithm is given very accurate results regardless the initial condition. The bad data have effect on very accurate of result on this estimation. The window had found five samples per cycle at frequency 50Hz.

The reference (two digital filtering algorithm for fast estimation sy.com) estimated the symmetrical components of the power system using by digital filter but two digital filters are working together. The first filter present base on Î±-Î² transformation. This transformation method is carried out from three phase unbalanced system to two phase system which is worked at transformation harmonic of order 3. The second filter transformation is developed by the first filter. From the digital sample the a time domain model is provided to calculated the magnitude and phase angle of each sequence components and the least error square algorithm also is used to calculated the magnitude and phase angle of the sequence components which is shown number of sample and sampling frequency these are effect on the estimation parameters.

The reference (Symmetrical Components Estimation Through

Nonrecursive Newton-Type Numerical Algorithm) presents, the Non recursive Newton type algorithm is used to estimation of symmetrical components which is extended with second stage algorithm to calculate of symmetrical components from the estimated fundamental phases of three phase voltage and current. This algorithm is not satisfied to changes of frequency harmonic distortion in three phase input signals of power system.

Power system is widely used in three phase system and large complex system. During the normal condition, these systems have in balance condition and hence can be made as an equivalent single phase system to become unbalance which is called as unsymmetrical. The unsymmetrical faults are open circuit, line-line, line-ground and line-line-ground.

The method of symmetrical components is developed in 1918 by C.L.Fortescue. This method is used by powerful technique for analyzing unbalance in three phase system. Fortescue is defined a linear transformation method which is developed from phase components to a new set of components these are called as symmetrical components. The liner transformation is representing an unbalance three phase system by a new set of three balanced in three phase system. Fortescue theorem is applied to three unbalance phases in three phase system. The following balanced system sets of components can be resolved. The set of three phase unbalanced voltage and current are designed as a, b and c.

Positive sequence components- consist of three phase displaced from each other by 120Â° in phase, equal in magnitude with the same phase sequence as the original phases.

c1

a1

b1

2. Negative sequences components- consist of three phase displaced from each other by 120Â° in phase, equal in magnitude with the opposite phase sequences as the original phases.

b2

a2

c2

Zero sequences components- consist of three phase equal in magnitude and with zero phase displacement from each others.

ao

bo

co

The original phase voltage is given as Va,Vb and Vc. The subscripts a,b,c and 1,2,3 refer to three phase voltage with positive sequence, negative sequence and zero sequence respectively. The unbalance voltage is shown below with symmetrical components.

Va = Vao+Va1+Va2 [1]

Vb = Vbo+Vb1+Vb2 [2]

Vc = Vco+Vc1+Vc2 [3]

The symmetrical component is displaced from each others by 120 used by a operator. The a operation is developed the relation between the symmetrical components and that phase displacement. The a operator is shown below by complex number.

a = 1< 120 = -0.5+j0.866 [4]

Phase voltage is expressed using by a operator.

Va = Vao+ Va1+ Va2 [5]

Vb = Vao+ aÂ²Va1+ aVa2 [6]

Vc = Vao +aVa1 + aÂ²Va2 [7]

The above equation can be written with matrix form

= [8]

Where A matrix is defined.

A = [9]

The matrix AâŒÂ¹ is defined as

AâŒÂ¹ = [10]

Both side multiply by AâŒÂ¹ at equation (8)

= [11]

Va0 = 1/3 (Va + Vb + Vc) [12]

Va1 = 1/3 (Va + a Vb + aÂ²Vc) [13]

Va2 = 1/3 (Va + aÂ²Vb + a Vc) [14]

Where Vao, Va1 and Va2 are given as positive sequence, negative sequence and zero sequence components of voltage respectively.

Hence positive sequence, negative sequence and zero sequence components of three phase voltage can be determined with original phase voltage.

The current is also written similar to the voltage equation.

The original phase current are given as Ia,Ib and Ic. The subscripts a,b,c and 1,2,3 refer to three phase current with positive sequence, negative sequence and zero sequence respectively

Ia = Iao + Ia1 + Ia2 [15]

Ib = Ibo + Ib1 + Ib2 [16]

Ic = Ico + Ic1 + Ic2 [17]

Here Ia, Ib, Ic are given as phase current and Ia0, Ia1 and Ia2 are given as positive sequence, negative sequence and zero sequence components of currents respectively.

= [18]

Symmetrical components is defined as

= [19]

Ia0 = 1/3 (Ia + Ib + Ic) [20]

Ia1 = 1/3 (Ia + a Ib + aÂ²Ic) [21]

Ia2 = 1/3 (Ia + aÂ²Ib + a Ic) [22]

PROBLEM ANALYSIS

During the unbalance condition on transmission line, the fault current and fault voltage must be developed. This condition can be called unsymmetrical condition. These fault present between line-line-xxxxxxx. during these kind of fault occur on the transmission line, need to calculated what are the line-line fault current and fault voltage xxxxxxxxxxxxxxxxx using by hardware and software.

The hardware is carried out by printed circuit board (PCB) as well as software is carried out by MATLAB designing. This chapter deals with problems that might occur in design and simulation of PCB layout circuit similar matlab design and simulation. The design of the PCB layout is be carried out by using the Proteus software. At firstly using with of ISIS software the circuit which is to be designed is made in it and is stimulated. Before design the pcb layout through Proteus software, components had to identified so what kind of components are needed for pcb designing.

In this project, transmission line voltage and current are needed to measure but transmission line contains high voltage so unable to measure with the pcb because pcb might be burn due to high voltage. the high voltage must be step-down to low voltage hence the voltage transformer can be used for this process. The voltage transformer present whether from high voltage to low voltage (step down) or from low voltage to high voltage (step-up), therefore During the pcb design assemble, single phase (230V) can be used as a input voltage source because transmission line has high voltage so difficult to measure that. When the fault occurs of this system, the voltage and current can be measured this process is to be carried out using by electronic devices.

When the fault occurs on the three-phase line, the voltage might be increased; here auto transformer would be used for changing voltage from system voltage therefore if whether increased or reduced system voltage using autotransformer the fault might be develop on the system hence fault current and voltage can be measured.

The input voltage was 230 voltages (AC) which is to be step-down to low voltage then converted direct current (DC) because mainly using microcontroller which is needed DC input. Dc voltage is as a analogue wave form which is converted analogue to digital converter (A/D converter). The microcontroller connected with LCD display which is shown out put result according to the programme.

The microcontroller can be programmed to operate with the assembly codes were to be written using PIC C language.

The input voltage (AC) step-down to low voltage using by voltage transformer as well as input current step-down using by current transformer. Those transformers called as instrument transformer which is mostly used protection device such as relay, circuit breaker.

Next Alternative Voltage (AC) is converted to Direct current (DC) using by rectifier. Normal rectifier has diode which is allowed maximum voltage 0.7V but if needs to get more than 0.7V this rectifier unable to use. so precision rectifier can be used which is allowed the voltage. Precision rectifier contain operational amplifier which is needed to DC power supply as well as microcontroller and LCD display those would be given DC power supply. Mostly electronics device is worked at DC voltage. DC power supply would be getting from DC power generator or rectifier.

Precision rectifier contains resistor, capacitor, operational amplifier and diode which can be useful for high-precision signal processing. Shunt resistor is used for current converted as a voltage. PCB is to be construction by those electronic devices such as resistor, capacitor, operational amplifier, diode, shunt resistor, current transformer, voltage transformer and micro controller.

The design of the PCB layout is being carried out by using the Proteus software. At first with use of ISIS software the circuit which is to be designed is made in it and is stimulated. This software gives the idea of expected output. Errors might occur due to improper connections which can be rectified. Then the circuit is designed in ARES software which gives the designed layout and the designed layout is being sent for printing on a laminated sheets. The design layout which is made in ARES software must code the pads and traces. If these pads and traces are not properly notified to technician making the circuit on laminated sheets then the problem occurs as their might be improper connections which leads to improper or not functioning of the circuit. The pcb has a two side such as components side and soldering side.

Other problem that might occur in designing of printed circuit board is drilling. Drilling is to be carried out carefully as even a scratch on any part of the circuit may disconnect the connection between the components. Soldering plays a major role in PCB design as the circuit is a single sided one and the soldering is to be performed on the side where printing is being done. It should be kept in mind to place the correct components at the correct place or else one mistake can make the circuit won't work and if soldering is done badly then getting the required output becomes difficult.

Next the circuit layout is to be designed using by proper software. In electrical power system mostly used two kind of software one is MATLAB software another one is Power World Simulator. In matlab software contain so many function.

The Matlab software can be get simulation wave form,

PROBLEM SOLUTION

This chapter deals with answers for the problems discussed. In this project, the circuit is designed by hardware and software. Previous chapter analysis what are requirement needed to make hardware and software circuit, this chapter going to present how to make hardware and software circuit.

Hardware design

The hardware circuit is designed on printed circuit board (PCB).

The design of PCB layout is carried on Proteus software. First the design of PCB layout is to be carried out in ISIS software where it is being made and tested. By careful design of the circuit errors can be erased and the circuit can be stimulated. After completion of design and stimulation, the circuit is now being made in ARES software as this circuit can be code into a format and can be handed forward to technicians makes the software designed circuit on the hardware. The circuit which is being designed should be error free. This can be done by clearly indicating the pads and traces which makes the design understandable and helps the placing of component at the right place. The PCB has two side components side, components are fitted at components side as well as solder would be made at soldering side.

The aim of this project, current and voltage are measured in fault condition of the transmission line but domestic supply or single phase is used instead of transmission line because not possible to transmission line due to high voltage therefore single phase supply is connected to PCB circuit. When Single phased connected with load meanwhile that voltage can be verified used by whether autotransformer or voltage regulator to make fault. During the fault, the voltage and current are to be measured. The single phase voltage is 230V (AC) so need to reduced as a 5V the voltage transformer is best to done this. The voltage transformer present whether step-up or step-down current and voltage transformer characteristics need here.

These transformers are given low voltage with AC voltage. The microcontroller is needed DC voltage as input therefore AC voltage is converted to DC voltage using by precision rectifier which has resistor, capacitor, operational amplifier, and diode. The full wave precision rectifier is the combination of half wave precision rectifier and summing amplifier. The resistor value are given depend on the circuit. Operational amplifier

MPLAB-ICD-2

Mp-lab-2 is connected between PC and PCB. PC and MP-LAB-2 are connected with six connector cable as well as Mp-lab-2 and PCB is connected with USB cable. The c programme is transferred from PC to PCB through MPLAB-ICD-2. The C programme is written on PC with MPLAB-IDE. Â MPLAB ICD 2 can be used to program the Flash-based microcontroller.

MP-LAB-2

PCB

PC

Microchip pins Name

RJ 12 Jack pin out

VPP/MCLR

1

VDD

2

VSS

3

PGD

4

PGC

5

No Use

6

MPLAB ICD 2 pins connected with RJ12 of PCB

MPLAB-IDE

MPLAB-IDE Integrated Development Environment (IDE) Software is used to microcontroller. This is mostly used in embedded applications. The C programme is written on MOLAB-IDE window at PC which is transferred to microcontroller through MPLAB-ICD-2. MPLAB IDE has components called as debuggers. This software simulator was for all devices to help test the code. Even if the hardware is not yet completed, that can be beginning testing the code with the simulator, a software program that simulates the carrying out of the microcontroller. The simulator can be measured code Execution time, single step through code to observe variables and peripherals, and trace the code to produce a detailed record of how the program ran. Once the hardware was in a prototype stage, a hardware debugger, such as MPLAB ICE or MPLAB ICD-2 can be used. The MPLAB ICE actually replaces the microcontroller in the target using a high-speed probe to give you full control over the PCB. The MPLAB ICD 2 can be stop and start program implementation, allowing testing the code with the microcontroller in place on the application.

PIC

The microcontroller has been used for this project was from PIC series. PIC microcontroller was the first RISC based microcontroller fabricated in CMOS (complimentary metal oxide semiconductor) that used separate bus for instruction and data allowing simultaneous access of program and data memory. The main advantage of CMOS and RISC combination was low power consumption resulting in a very small chip size with a small pin count. The main advantage of CMOS was that it had immunity to noise than other fabrication techniques.

Various microcontrollers offer different kinds of memories. EEPROM, EPROM, FLASH etc. and were some of the memories of which FLASH was the most recently developed. Technology that is used in pic16F877 was flash technology, so that data is retained even when the power is switched off. Easy Programming and Erasing were other features of PIC 16F877.

CORE FEATURES:

1. High-performance RISC CPU

2. Only 35 single word instructions to learn

3 All single cycle instructions except for program branches which are two cycle

4. Operating speed-DC - 20 MHz clock input,

DC - 200 ns instruction cycle

5. Up to 8K x 14 words of Flash Program Memory,

Up to 368 x 8 bytes of Data Memory (RAM)

Up to 256 x 8 bytes of EEPROM data memory

6.Pin out compatible to the PIC16C73/74/76/77

7. Interrupt capability (up to 14 internal/external

8.Eight level deep hardware stack

9.Direct, indirect, and relative addressing modes

10. Power-on Reset (POR)

11. Power-up Timer (PWRT) and Oscillator Start-up Timer (OST)

12. Watchdog Timer (WDT) with its own on-chip RC Oscillator for reliable operation

13. Programmable code-protection

15. Power saving SLEEP mode

16. Selectable oscillator options

17.Low-power, high-speed CMOS EPROM/EEPROM technology

18. Fully static design

19. In-Circuit Serial Programming (ICSP) via two pins

20.Only single 5V source needed for programming capability

21. In-Circuit Debugging via two pins

23.Wide operating voltage range: 2.5V to 5.5V

24. High Sink/Source Current: 25 mA

25. Commercial and Industrial temperature ranges

26. Low-power consumption:

2mA typical at 5V, 4 MHz

20mA typical at 3V, 32 kHz

1mA typical standby current

PERIPHERAL FEATURES:

â€¢ Timer0: 8-bit timer/counter with 8-bit prescaler

â€¢ Timer1: 16-bit timer/counter with prescaler, can be incremented during sleep

Via external crystal/clock

â€¢ Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler

â€¢ Two Capture, Compare, PWM modules

Capture is 16-bit, max resolution is 12.5 ns,

Compare is 16-bit, max resolution is 200 ns,

PWM max. Resolution is 10-bit

â€¢ 10-bit multi-channel Analog-to-Digital converter

â€¢ Synchronous Serial Port (SSP) with SPI. (Master Mode) and I2C. (Master/Slave)

â€¢ Universal Synchronous Asynchronous Receiver Transmitter (USART/SCI) with

â€¢ Brown-out detection circuitry for Brown-out Reset (BOR)

PROBLEM IMPLEMENTATION

The focus of this project determines the voltage and current during the unbalanced condition. These are carried out hardware and software. Hard ware is developed by printed circuit board (PCB) similar software is developed by MATLAB/SIMULINK. The hardware was designed at project laboratory using by some electronic devices and software was designed through the computer at computer laboratory.

HARDWARE DESIGNING

The voltage and current measurement was important of focus this project. These measurements are carried out through the hardware. The hardware is designed as a printed circuit board (PCB). Initially PCB was designed through the Proteus software. The PCB layout was first designed using ISIS software and simulated in order to know whether the circuit which was designed properly working or not. After checking was carried out, the circuit in as ISIS software the next step is converted into a PCB layout using ARES (Advanced Routing and Editing Software). The ARES software layout was sent to printed circuit designer who would be made the design on laminated sheets. After receiving the printed circuit board on a laminated sheet, the circuit was checked for similarity whether it was similar to one which had been given for construction.

The PCB had two sides one was soldering side another one was components side, the soldering side had one with copper tracks only on one side of the PCB. During the PCB designing the copper tracks should not cross over the each others. The components are fitted on components side similar soldering is soldered on soldering side. Next step was drilling the circuit board is to be taking all the precautions as mentioned earlier. The all components are fitted only one side. The drilling is carried out on components side and same side components are inserted as directed. Soldering is carried out each by each components inserted. Drilling must be performed with all precautionary measures had been taken such as wearing the safety glass and covering nose with mask in order to avoid the small dust particles going on eyes and nose. Drilling is carried out using a 0.8mm, 0.9mm and 1 mm needle placing in the drilling machine and screw should be tightened after adjusting the position. During the drilling the holes was kept in mind to drill the holes wherever required and mostly avoids getting the needle scratches on the PCB which might be made the circuit mistake.

PCB construction needed components list below

Voltage transformer/ potential Transformer

Current Transformer

PIC

Resistors

Capacitors

Operational Amplifier

Diode

LCD

Variable resistor

Shunt resistance

RJ connector

Power pins

When each component inserted on printed circuit board with carefully because if make any mistake components might be damaged similar PCB copper tracker might be damaged.

The project goal was determined the fault current and voltage during the unbalance condition in transmission line but PCB is carried out with during the single phase supply because the transmission line fault current and voltage unable to measure with PCB circuit. The single phase supply is used as input source to PCB hardware. The voltage and current value are needed to measure the from this PCB hardware. Single phase voltage was 220V/240V AC that was reduced to as 5V using voltage transformer which is provided from 220V/240V AC to 5V.

The voltage transformer had primary (input) terminals and secondary (output) terminals respectively. The primary terminal is connected across the load the secondary terminal is connected to precision rectifier which is converted from alternative voltage to direct voltage similar current transformer had primary (input) terminals and secondary (output) terminals respectively.

The current transformer is connected as series between input source and load. The phase current was flow through current transformer primary terminal. The secondary terminal is connected to shunt resistance then following to precision rectifier. The precision rectifier is developed from alternative current to direct current. The shunt resistance is used for the current is converted as voltage.

V = I R [1]

Where V-voltage

I-Current

R- Shunt Resistance

Hence the current is converted as voltage according to the equation [1]. The analogue digital converter (ADC) is operated from analogue signal to digital signal. But current signal could not convert as an analogue signal therefore current is needed to convert as voltage.

CURRENT MEASUREMENT

230V AC

R5

R1 R2 R3 R4

CT SR U1 D1 U2

R8

R6 D2 R7 To PIC

Block Diagram-

Where

R1, 2, 3, 4, 5, 6, 7, 8-Resistors

VR1- Variable Resistor

C1-Capacitor

U1 &U2- Operational Amplifier

D1 & D2- Diode

SR-Shunt Resistor

CT- Current Transformer

This circuit is designed to measure the current. The current has to monitor was step down by the current transformer. The step down current was converted by the voltage with the help of shunt resistor. Then the converted voltage is rectified by the precision rectifier. The precision rectifier was a configuration obtained with an operational amplifier in order to have a circuit behaving like an ideal diode or rectifier. The full wave rectifier is the combination of half wave precision rectifier and summing amplifier.

The input voltage is operated as a negative the diode, there was a negative voltage on the diode. Hence which is worked as a open circuit. The current was not in the load the output voltage was zero. The input voltage operated as a positive which was amplified by the operational amplifier and diode function was ON. There was in the load and due to feedback hence output voltage was to the input.

In this block diagram (x) input is operated as greater than zero, diode 2(D2) was ON meanwhile diode 1(D1) OFF hence output was zero. Input is operated as less than zero diode2 (D2) was OFF and diode 1(D1) was ON, and the output was similar the input with an amplification of -R2/R1. The full wave rectifier is developed that half wave rectifier and the summing amplifier were precision circuits.

Then the output of the rectified voltage is adjusted to 0-5v with the help of variable resistor VR1. Then given to ripples are filtered by the C1 capacitor. After the filtration the corresponding DC voltage is given to analogue to digital converter (ADC).

VOLTAGE MEASUREMENT

230V AC

R5

R1 R2 R3 R4

VT U1 D1 U2

R8

R6 D2 R7 To PIC

Block Diagram-

Where

R1, 2, 3, 4, 5, 6, 7, 8-Resistors

VR1- Variable Resistor

C1-Capacitor

U1 &U2- Operational Amplifier

D1 & D2- Diode

VT- Voltage Transformer

This circuit was designed to measure the voltage. The voltage had to monitor was step down by the voltage/potential transformer. The transformer secondary voltage was as 0-5V. The step down voltage was rectified by the precision rectifier. The precision rectifier was a configuration obtained with an operational amplifier in order to have a circuit behaving like an ideal diode or rectifier. The full wave rectifier is the combination of half wave precision rectifier and summing amplifier. The input voltage is operated as a negative the diode, there was a negative voltage on the diode. Hence which is worked as a open circuit. The current was not in the load the output voltage was zero. The input voltage operated as a positive which was amplified by the operational amplifier and diode function was ON. There was in the load and due to feedback hence output voltage was to the input.

In this block diagram (x) input is operated as greater than zero, diode 2(D2) was ON meanwhile diode 1(D1) OFF hence output was zero. Input is operated as less than zero diode2 (D2) was OFF and diode 1(D1) was ON, and the output was similar the input with an amplification of -R2/R1. The full wave rectifier is developed that half wave rectifier and the summing amplifier were precision circuits.

Then the output of the rectified voltage is adjusted to 0-5v with the help of variable resistor VR1. Then given to ripples are filtered by the C1 capacitor. After the filtration the corresponding DC voltage is given to analogue to digital converter (ADC).

The precision rectifier contain operational amplifier which is needed to power supply to operate. The requirement power supply was 15V DC which is obtained regulator power supply equipment from the laboratory as well as PIC and LCD had to need power supply (DC). The PIC and LCD the requirement power supply were 5V DC which is obtained regulator power supply equipment from the laboratory.

The PIC contain 8 bit analogue digital converter (ADC) which is developed from analogue signal is converted as digital signal. The PIC microcontroller 16F877 is used as the programme memory. This microcontroller is provided data and instruction.

The PIC microcontroller 16F877 was used as the program memory with . The main purpose of this micro controller was to provide data and instructions as per the request of the central processing unit. The PIC 16F877 had forty pins but thirteen pins are used for this implementation such as pins were 1,15,16,19,20,21,22,27,28,29,30,39,40

Pin-15 is connected with voltage measurement circuit output terminal

Pin-16 is connected with current measurement circuit output terminal

Pin- 19, 20, 21,27,28,29 and 30 are connected with LCD

Pin-11 and 32 are connected with DC power supply at positive point

Pin-12 and 31 are connected with Ground.

Those pin are connected respectively.

RJ12 Connector is operated as bridge between PIC and Computer. The programmes written by C language then send the data to the microchip through the MPLAB ICD2. The PIC C program is developed and implemented for the current and voltage measurement. The MPLAB IDE is used to compile and simulated the PIC C codes help with PC. The Mp-lab-2 is connected between PC and PCB. PC and MP-LAB-2 are connected with six connector cable as well as Mp-lab-2 and PCB is connected with USB cable.

Screen shot of the selected PIC

Screen shot of the Program file

Screen shot of program file on the window

LCD Designing

LCD display is connected with PIC and power supply. The LCD would be shown measurement of current and voltage value.