누전차단기와 CT1 서지방호장치의 서지협조의 분석

Abstract

The objective of this paper is to present whether the surge coordination between connection type 1(CT1) surge protective devices(SPDs) and built-in varistors of residual current device(RCD) for application to energy storage system is established. L-N mode surge coordination characteristics of CT1 SPD connected in parallel with RCD were investigated. The test voltage was supplied by a combination generator, capable of outputting a 10kV voltage, 5kA current into a 2Ω load. BR As a result, the built-in varistors of all sample RCDs against incoming surges were conducted. Most of the incoming impulse currents flows into the built-in varistor of RCD, and some RCDs was damaged at the impulse current of more than 2.5kA. Surge coordination between RCD and CT1 SPDs was not achieved. In addition, the minimum value of continuous operating voltage(Uc) for SPD connected between phase conductor and ground in TT grounding system should be a value of 1.5USUB0/SUB, where USUB0/SUB is the voltage to ground. Some SPDs used in this work are not acceptable to the above requirement.