交流滤波器保护装置误动分析及其改进

Analysis on the Mal-operation of AC Filter Protection and Its Improvement

针对云广直流输电工程试验过程中出现的交流滤波器保护误动作事件,分析保护装置和故障录波器的故障录波,指出采样过程中的频率混叠是导致保护误动的原因,且由于不同保护装置采样的相对时差导致采样结果中频率混叠程度有差异,从而造成了双套保护动作行为的不一致。对保护装置提出了两项改进措施,进行了效果验证,并做了多种工况下RTDS仿真试验和现场故障波形回放试验。试验结果表明,保护装置经改进后可以有效地避免功率调整过程造成的保护误动。

Aiming at the AC filter mal-protection trip in testing processing of Yunnan-Guangdong HVDC transmission project,this paper analyses the waveform of protection device and transient fault recorder,points out that frequency aliasing in sampling is the root cause of mal-operation,also,as to the relative time difference in sampling,the frequency aliasing level is different in disparate protection device,which lead to different action result of bi-protection.Improvement measures on frequency aliasing is proposed and validated according to test on protection device.Moreover,this paper makes simulation test in most situations with RTDS testing system and playbacks the fault recording on protection device.The simulation result shows that the improvement measure could avoid the mal-operation caused by power adjusting effectively.