Transients and Transient Suppressors for Power Conversion Equipment

Transient protection for electronic equipment is becoming an important issue. This paper will discuss the nature of transients, maximum voltage, and maximum currents available at different locations in ac distribution systems, as well as the frequency of occurrence of such transients based on IEEE Std. 587. The important role of the ac distribution system in connection with transient suppressors is defined and explained. The various shunting type transient suppressor technologies are mentioned, and some of their most important characteristics are shown. Some combinations of hybrid suppressors are shown, and their advantages and short-comings are explained. The zinc oxide varistor, the most popular of the shunt type suppressor, is treated in great detail, and its important parameters are explained.