Snubber Design for Transformer Protection

Abstract

Historically, failures of distribution transformers due to transient overvoltage phenomena have led to the development of resistor–capacitor snubber circuits for the protection of the transformer and winding insulation. These transients are most often observed when dry-type transformers are close coupled to vacuum switching devices. Typically, snubber circuit design has been specific for the particular application, and complex engineering studies were required. However, the design of a snubber circuit itself may be performed without these detailed studies. If snubber studies are required, the procedures for system modeling and simulation are explained in a step-by-step manner.