摘要
为了解决500 kV西百乙线串补无熔丝电容器组电容器不平衡保护错误动作的问题,通过对动作时刻波形的理论分析,确认由于电容器不平衡电流中的高次谐波电流分量造成电容器不平衡保护错误动作。研究过程中,通过PSCAD仿真,对比分析了6种工况下的电容器不平衡电流,发现由于电容器电流中含有了谐波分量,在杂散电感和电容器分支电流互感器的共同作用下,导致保护装置采到的电容器不平衡电流被放大。为了解决上述问题,考虑到可行性,提出了在采样二次回路中串入椭圆低通滤波器的方案,该滤波器的截止频率为400 Hz,经过试验验证,该方案可滤除电容器不平衡电流中的高次谐波分量,解决不平衡保护误动的问题。
For solving the problem of the mal-operation of unbalanced operation of capacitor of 500 kV Xibai FSC non-fuse capacitor bank,the mal-operation of unbalanced protection of capacitor due to higher harmonic current component in the unbalanced current of capacitor is confirmed by the theoretical analysis of waveform at the time of operation.During the study,the unbalance current of capacitor under 6 conditions is compared and analyzed through PSCAD simulation,finding that the unbalanced current of capacitor picked up by the protection device is enlarged due to.harmonic contents in the capacitor current and under the action of both stray inductance and the branch current transformer of capacitor.For solving the problem and also considering the feasibility,the proposal of connecting ellipse low pass filter in series in the sampling secondary circuit is put forward.The cut-off frequency of the filter is 400 Hz.It is proved by the test that the proposal can eliminate higher harmonic component in the unbalance current of capacitor and solve themal-operation problem of unbalanced protection.
作者
陈远俊
梁兴海
周启文
王德昌
周小鹏
CHEN Yuanjun;LIANG Xinghai;ZHOU Qiwen;WANG Dechang;ZHOU Xiaopeng(NR Electric Co.,Ltd.,Nanjing 211102,China;EHV Power Transmission Company of CSG,Guangxi Baise 533000,China)
出处
《电力电容器与无功补偿》
北大核心
2019年第6期12-17,共6页
Power Capacitor & Reactive Power Compensation
关键词
低通滤波器
高次谐波
电容器不平衡电流
串联补偿
low pass filter
higher harmonic
capacitor unbalance current
series compensation
