厂用6kV系统过电压分析与限制措施

Analysis and Limiting Measures for Over-voltage of 6 kV House-service System

由于真空断路器的灭弧室有独特的灭弧能力,在开断变压器、高压电动机等感性负荷时,因电弧电流在过零点之前就被强行截断,而产生截流过电压,威胁电网的固体绝缘。介绍了北京京能热电股份公司由此导致的多条6 kV交联聚乙烯电缆绝缘损坏,并针对真空断路器的操作过电压采取了有效的限制。

When inductive loads such as transformer and HV motor were cut off, arc current was cut off before zero-crossing for special arc suppressing ability of vacuum circuit breaker, and then voltage surge occurred. This surge is harmful to solid insulation of house-service system. It leads to XLPE insulation berakdown of many 6 kV transmission lines of houes-service system of Beijing Jingneng Thermal Power Co. Ltd. limiting measures were also adopted to suppress the switching surge of vacuum circuit breaker.