Microcontroller based semiconductor tap changer for power transformer

A prototype of a fully electronic on-load semiconductor tap changer for power transformer has been designed and built. With the emergence of high power semiconductor devices, problems associated with the mechanical on-load tap changer have been properly rectified. In this work, the prototype was constructed with triacs as the switching devices and microcontroller as the triggering circuit. The results obtained from this work show that the prototype has a faster time response of approximately 0.44 s to react to any load changes. It also produces no arching problems as it has no mechanical contacts and requires no maintenance, and can be considered as one of the fast solutions of the voltage sag or voltage swell. The system has been tested for reliability and proven to be reliable in maintaining the output voltage of the system.