两端接地断路器分、合闸时间测试方法研究

高压断路器的分、合闸时间测试能够评估断路器的机械特性以及三相同期性能。安全规程要求对断路器进行维护和测试时,必须将断路器两端接地,防止过高的感应电压对人员和设备造成损害。传统的断路器分、合闸时间测试方法由于受到大地电阻回路的影响,无法在两端接地的情况下进行。文中首先分析了断路器仅一端接地时存在的风险;然后又介绍了一些常见的新方法,如动态电阻测试(DRM)和两种高频测试法的原理以及可能存在的问题。经过理论分析、试验和现场实测,提出了一种基于变频谐振的动态电容测试(DCM)的两端接地测试技术。这种方法不仅得到的分、合闸时间结果与传统的单端接地方法得到的结果完全一致,而且还能够高效、安全地完成对GIS等封闭式断路器的测试。

Research of Timing Testing Method on Circuit Breakers with Both Sides Grounded

Timing test for high voltage circuit breaker is used to evaluate the condition of mechanical components of circuit breakers and phase synchronizations. Safety regulation requires the circuit breaker under maintenance must be grounded on both sides to avoid the damage caused by high induced voltage. However, one grounded side has to be removed before carrying out conventional timing test due to low resistance of ground circuit. In this paper, the risk of testing one side grounded circuit breaker is analyzed. Then some commonly used new technology, the dynamic resistance measurement (DRM), as well as two high frequency technologies are introduced. After theoretical analysis, experiment and field testing, the dynamic capacitance measurement (DCM) technology which is based on the variable frequency resonance is the most reliable dual ground testing method. It is able to give timing results highly consistent with that from the conventional method. Meanwhile, the DCM method can be used to test the GIS breakers safely and efficiently.