DESIGN AND IMPLEMENTATION OF A THREE PHASE 6KVA AUTOMATIC PHASE SELECTOR IN A THREE PHASE SUPPLY CIRCUIT
Lawal, Abdur-Raheem O., Jimoh, Adeyemi A., Lawal, Olatunji A., Tiamiyu, Ahmed. K on 06/01/2017
The variation in voltage level per phase in a three phase supply circuit posed challenges in industrial power system. In this regard, this project was designed and implemented to check the availability of any live phase, and connects the load to the available live phase only. This feat was achieved with microcontroller (PIC16F628). This controller continuously checks for which of the three phases is having supply at any point in time and the load is connected to an active phase relay by the controller. The relay is driven with a transistor. This project monitors the availability and level of voltage on the three phases and selects the most suitable one. The phase is switched to the output and automatically transferred to the next available phase in the event of failure of the previously selected phase through the electromechanical switches used in the circuit. If the voltage supply on all the phases is low(less than 180v) or is high (above 220V), the device will go into the delay mode until there is a phase with voltage between 180V and 220V. This device switches between phases within fraction of a second. This is required for continuous power supply to appliances and loads. An LCD (Liquid Crystal Display) is provided to display the status of the phase.