DEVELOPMENT AND TESTING OF THREE-PHASE AUTOMATIC PHASE DISCRIMINATOR

Abstract

Power supply in Nigeria has degraded to a level that many residential buildings now have three or two power supply lines connected to each building(big or small) at the usual nominal 240V a.c supply. The standard practice in a developed country where there is stable and reliable power is to have one single phase line in a typical small building. Usually, a Nigerian consumer in this setting connected to three phase manually transfers the fuse to an active line or phase where there is quality power. This manual engagement, though unacceptable is dangerous to life and property. It is also time-wasting. A better work can be done by using a three phase automatic phase discriminator. The device displays the voltage level available on each of the phases connected to the house and then switches on to the one with high quality power output. A programmed intelligent microcontroller PIC16F877A was used. The device was also subjected to continuity test during which contactors and relay coils showed low resistances at their terminals. Finally, the circuit was simulated on Proteus and Electronics Software to further confirm its workability and efficiency. The overall performance was very good.