Design of microcontroller based Thyristor Controlled three-phase static volt-ampere reactive compensator

To confine on system stability and reliability, the reactive power compensation is the fundamental way for Flexible AC Transmission System (FACTS). The variations of reactive power have an effect on the generating units, lines, circuit breakers, transformers, relays and isolators. Moreover the additional current flow associated with reactive power can be cause to increase losses and excessive voltage sags. Therefore the local Volt-Ampere Reactive (VAR) compensator which is comprised of shunt reactors is used in transmission and distribution system for reactive power compensation. The conventional electro-mechanical reactive power compensator is not suitable for its slow switching action which cannot proportionate with the rapid changing system load. The electronic reactive power compensator uses fast switching action than the conventional relay. The Static VAR Compensator (SVC) is the arrangement of Thyristor Switched Capacitor (TSC) and Thyristor Controlled Reactor (TCR). In this paper, microcontroller based three-phase SVC system is designed using thyristor controlled switch. Microcontroller is used for fast and precise switching of the thyristor which adds a significant feature of this designed SVC.