The Application of Supercapacitors for Limitation of Switching Overvoltage in dc Auxiliary Installations of Power Plants and Substations

Abstract

The operation experience of DC auxiliary installations in power plants and substations testifies about periodically occurred failures, [1], [2]. According to statistics, [3], 70% of failures of relay protection operation occur as a result of overvoltage caused by: working of lightning rod, and internal switching in DC circuits, for example, short circuit clearing or switching of circuit breakers electromagnetic drives or DC motors. Previously, relay protection based on electromechanical relays and pole-to-pole overvoltage didn't cause such negative effects. With implementation of microprocessor technics, more sensitive to overvoltage, risk of failures and false tripping of relay protection and supervisory control devices in power plants and substations [4], [5] grew significantly.