The susceptibility of the microprocessor-based relay of high voltage substations to EMP

Abstract

Based on the transient electric field measurement in the 500 kV substations, the authors measured the EMP susceptibility of a set of microprocessor-based protection relay of high voltage substations to electromagnetic field pulse (EMP). The results of measurement show that the field suppression effect of shielding box of protection relay and the ability of relay to resist interference like as EMP are enough to be compatible in the maximal transient switching electric field in substations