高压直流开关是高压直流输电系统中的核心设备之一,其工作状态直接影响直流输电系统的安全稳定运行。为了实时准确地获取高压直流开关的运行状态和各项参数指标,提出了一种非接触式高压直流开关在线检测方法。该方法通过采集高压直流开关振荡回路电流,运用遗传算法计算出振荡回路RLC参数,采用小波理论分析振荡回路电流波形,进一步判断开关燃弧时间及开断过程各阶段工作状态。同时研制出高压直流开关的在线检测系统,通过对实验室模拟平台和士500kV直流换流站进行现场实验,可得其高压直流开关振荡回路电感参数测量误差限定在3.77%以内,电容参数误差限定在2.39%以内,实验结果充分证明了非接触高压直流开关的在线状态检测方法和装置对高压直流开关参数计算的正确性和可靠性。
As one of the core equipment of high-voltage direct-current (HVDC) transmission system, the status of HVDC circuit breakers directly affects the safe and stable operation of power system. Aiming at correctly getting real-time operating status and parameters of HVDC circuit breakers, we proposed a new type of non-contact online condition monitoring method. In this method, after sampling current in an oscillation circuit of HVDC circuit breaker, parameters of the oscillation circuit were calculated by using a genetic algorithm, and the wavelet theory was adopted to analyze the waveform of oscillating current so as to judge the arcing time and operating status in each stage of breaking process. Furthermore, online condition monitoring devices were developed, which were applied in both laboratory simulation and long-lasting field experiments in a ±500 kV converter station. In these cases, the proposed method had computation error of inductance within 3.26 % and computation error of capacitance within 2. 39%. The results prove the correctness and reliability of both the non-contact online condition monitoring technology for HVDC circuit breakers.