Protecting Medium-voltage Transformers From Electrical Transients

摘要

Protecting medium-voltage transformers from electrical transients is vital in the designing and commissioning of electrical distribution and protection systems. This article details how transients are produced and describes a mitigation method using snubbers. Asnubber is a resistor-capacitor (RC) network that is designed for the system. Snubbers are a cost-effective method of reducing switching-induced transients. At many installations that use medium-voltage switching, transformer damage is often attributed to lighting. However, this damage is likely caused by transients induced by switching. In a facility with on-site power generation and switching at medium-voltage levels, a power outage results in either a transfer between power sources or a transfer to the generators. The result could induce a transient that could damage the transformer; a snubber network can provide additional protection against damage.