DEVELOPMENT AND PERFORMANCE EVALUATION OF AN INTELLIGENT ELECTRIC POWER SWITCH BETWEEN THREE SOURCES

Abstract

Power supply failure does not promote development to public and the private sector. Processes such as surgery operation in hospitals, research activities and even communication at airports are so important that their interruption can be calamitous. As electric power sources are limited and unstable in Nigeria, there is the need to manage available sources to provide uninterrupted electric power. This research had focused on the design and construction of an intelligent electric power switch that is able to feed a load from three sources (mains, power-inverter and gasoline generator) with very good load transfer time lag. This switch transfers the load to the inverter immediately there is mains supply failure and continues to monitor the battery voltage level. Any voltage below the preset threshold voltage of the battery would automatically startup the standby generator. The generator output voltage stability is first monitored before transferring to the load. If the main is restored or the inverter battery is fully charged, the system automatically transfers the load to either of the available source and turns OFF the generator. All switching and control system was achieved using a microcontroller (Arduino Uno) with LEDs to indicate which of the sources is available.