A novel thyristor-assisted tap changer scheme

On-load tap-changing power transformers are an essential part of any modern power system, since they allow voltages to be maintained at desired levels despite load changes. This paper describes a new thyristor-assisted tap changing scheme which has selector and divertor units, as in a traditional tap changer, but these need not be in separate compartments. The scheme is shown and its operation is explained in detail. The constituent parts of the tap changer are also described.