A novel thyristor assisted diverter switch for on load transformer tap changer

In this paper, a novel thyristor assisted diverter switch for on load transformer tap changer is presented, which can eliminate excessive conduction losses and suppress the arcing in the diverter switch, which are inherent in traditional on load transformer tap changers. The presented on load transformer tap changer has selector and diverter units. The selector has the same circuit ´configuration and the same operation principle as the traditional tap changer. The proposed novel thyristor assisted diverter switch is described in detail in this paper, which features the thyristor pairs substitute transition resistors. The triggering circuit, the key part of the diverter switch, is designed, which is controlled by single chip processor in this paper. Besides, an experimental thyristor assisted diverter switch is also developed in this paper. Experimental results are presented, showing that the proposed diverter switch is feasible.