Design and Implementation of Hardware Reconfigurable Three-Mode Automatic Change-Over System

Abstract

Automatic change over system is a technique that ensures uninterrupted power supply in a building. It can also be designed to optimize the cost of electricity usage. Two-mode automatic change over system is common. Given the rising cost of electricity in recent times especially in developing country like Nigeria, many individuals and cooperate organizations now have three independent sources of power: photo voltaic, grid and generator power supplies, in attempt to optimize the cost of electricity. There is therefore a need to have an automatic change over system that is both configurable and maintainable to meet user’s needs. This work designed, simulated and implemented a hardware reconfigurable three-mode automatic change-over system. The mathematical models of the considered independent sources were considered before developing a state matrix that can be used to reconfigure the input sources to match user’s priority when installing the change-over system. The state diagram of the system was developed before simulating the system using Simulink in MATLAB. Relay logic was used to implement the state matric while AC contactors and relays were used to implement the physical system. The system showed optimal performance after testing and exhibited a near zero response time. It is expected that availability of this system will be optimal given that the system components can be locally sourced in case of component failures.