THREE PHSE AUTO CONVERSION SYSTEM

INDEX

This is a picture showing the connection of the project here the sensing circuit gives the 8051 command used to detect the phase presence. Also as the m.p detects the phases it gives outputs and takes inputs from the ports. Which provide signal to uln2803 and then the ic gets activated and relay gets activated. As relay gets activated the it shifts its position and gets to another position which is connected to the other phase. When phase comes back uln 2803 is signaled and then it signals relay and relay gets back to its previous position.h

LIST OF ITEMS USED:

items details pricetransformer 800 ma 12+12 65 each * 3470 uf capacitor 50 volt 7 each *347 uf capacitor 50 volt 5 each * 37805 12 to 5 volt 12 each *4Bridge rectifier ic 15 each *320 diodes 2 amp 2 * 208 wire connectors 5 5 *25Fuse + socket 5 amp 15 *35 yards copper wire High amperage 10 *5Extra wiring Scavenged =20 approxLeds 10 *1resistors 15 *1Pcb board 130 * 1Ferric chloride powder 2 *20Soldering wire 120Wire holder 10 *1Uln2803 ic 8 transistor 30 *1Max 232 30 *1At89c51 microcontroller 80 *1Ic sockets 15relays 6 relays 25 *6Screws + nuts 20 20Zif socket 40 pin 150100 uf capacitor 747 uf +10 uf 15Pico farad capacitor 41 uf capaicitor 5 *48 resistor bridge 8Db 9 female 30project case 110Buttons spst 10 10 * 5Button reset 10 10 *5lcd 250keypad 150Drill bits 5 5 *5

Total:

PROJECT DESCRIPTION:

Main idea:

In this project we have attempted to make a three phase auto conversion system which when detects that a phase had gone off. After it detects that a phase had gone off it directly tells the microcontroller that the phase is off and the microcontroller after detecting the no of phases that are off converts the active phase( in which electricity is coming) to the corresponding phase e.g if ‘Y’ goes it gets the current from the ‘B’ phase and if ‘B’ goes it gets current from ‘R’ and vise versa.

Phase sensing circuit:

In this project we have used three transformers that convert the coming ac to the 220-12 volt range and then there is a filter circuit(capacitor and bridge rectifier circuit) that works as to remove ripples and convert the ac to dc then 7805 regulator is connected which outputs the voltage to 5 volts which can be read by the microprocessor.

Relay operated delta connection:

one of the main features of this circuit is that the circuit is controlled through microcontroller and in controlling the flow of the current , relay is used and uln 2803 ic is used as the current amplifier. When one phase gets , respective relay gets on which switches its path and connects it to the other phase and in that respect of connection , single phase provides to the load off the two phase combined.

Current protection circuit: (fuse)

I this project for the safety purposes fuses are used having a rating of 5 amp. When the load exceeds the 5 ampere range then the fuses burn out and protect the system from over amperage. This is basically required as a safety standard so that in any case the current shorts the fuses will blow out stopping the conducting path thus providing safety to short circuits.

Proteus simulation diagram:

XTAL218

XTAL119

ALE30

EA31

PSEN29

RST9

P0.0/AD039

P0.1/AD138

P0.2/AD237

P0.3/AD336

P0.4/AD435

P0.5/AD534

P0.6/AD633

P0.7/AD732

P1.01

P1.12

P1.23

P1.34

P1.45

P1.56

P1.67

P1.78

P3.0/RXD10

P3.1/TXD11

P3.2/INT012

P3.3/INT113

P3.4/T014

P3.7/RD17

P3.6/WR16

P3.5/T115

P2.7/A1528

P2.0/A821

P2.1/A922

P2.2/A1023

P2.3/A1124

P2.4/A1225

P2.5/A1326

P2.6/A1427

U1

AT89C51

D7

14D6

13D5

12D4

11D3

10D2

9D1

8D0

7

E6

RW

5RS

4

VSS

1

VDD

2

VEE

3

LCD1LM016L

R110k

R210k

R310k

The program reprocesses continuously that if there is load shed eg sensor detects no voltage then it turns on the relay and it gets to the other terminal relay. Thus if r phase is load shed then it connects to the y phase and there is electricity in r phase if now electricity come in the r phase then relay is switched off and the relay returns to normal state. This process is automatic and requires no attention from the user and it also checks wether the phases are in coming and indicates it through the leds.

Block diagram of the process of programming:

Pcb design: