A new on-load tap changing system with power electronic elements for power transformers

In order to avoid the disadvantages of conventional mechanical tap changing system and its influence on power system, a new on-load tap changing system with power electronic elements for power transformers is presented in this paper. The system is composed of main circuit, signal detection and triggering circuit design, choice of the thyristor switching, protecting transformer from overvoltage both in case of switching on and switching off no-load transformer. It possesses the inherent attributes of greater efficiency and less maintenance.