Design and Construction of an Automatic Transfer Switch for a Single Phase Power Generator

An Automatic Transfer Switch (ATS) for a single phase power generator has been designed to enable the automatic operation and transfer of power supply between a public utility supply and a power generator. The ATS, which is a switchgear control system, provides a functional system that provides an automatic switching of power supply between a primary source (public utility) and a secondary power source (generator). The methods employed in designing the ATS involve the use of electromechanical type relays, contactors, voltage monitoring relays and delay timer relays as main components of the system. Incorporated in the ATS is a digital multimeter (DMM) made up of a 12V d.c and a 5V d.c power supply unit, precision rectifier unit, current transformer and Microcontroller (PIC 16F877) to convert the measured analogue alternating current(a.c). voltage and current quantities to digital values for display on the liquid crystal display (LCD). The result of the automatic transfer switch demonstrates its ability to perform automatic power change over activities easily and with little or no human interactio