高压直流输电工程噪声滤波器性能评估

Performance Evaluation of Noise Filter for HVDC Transmission Project

近年来高压直流输电系统换流站交流PLC滤波器故障时有发生,为查明故障原因,对±500 kV溪洛渡直流输电工程送端昭通换流站交流PLC滤波器的配置方案、滤波性能和定值计算情况进行了研究。发现对该工程交流PLC滤波器性能研究及参数选型时,应力定值计算仅考虑了电抗器、调谐单元等附属元件承受最大稳态电压和电流应力需求,未考虑在弱交流系统甚至孤岛运行下交流PLC滤波器在直流操作及各类典型故障过程承受的暂态谐波电流电压应力情况,结合该工程某次直流紧急停运过程中发现交流PLC滤波器调谐单元承受的实际谐波电流应力显著超过其设计额定值,说明该设备存在较大安全隐患。针对高压直流换流站交流PLC噪声滤波器的设计选型、隐患设备评估整治等提出了相应的建议措施,具有一定借鉴意义。

In recent years,failures of AC PLC filters in HVDC converter stations have occurred from time to time.In order to find out the causes of these failures,the configuration scheme,filtering performance and constant value calculation of AC PLC filters in Zhaotong converter station of 500 kV Xiluodu HVDC transmission project are studied,it is found that the maximum steady state voltage and current stress of auxiliary components such as reactor and tuning unit are only taken into account in the stress setting calculation when the AC PLC filter is studied and its parameters are selected,not considering the transient harmonic current and voltage stress of AC PLC filter under DC operation and typical fault process in weak AC system or even isolated island.Combined with the DC emergency shutdown process of this project,it is found that the actual harmonic current stress of the AC PLC filter tuning unit is much higher than its design rating,which shows that the equipment has great hidden trouble.Finally,some suggestions are put forward for the design and selection of AC PLC noise filter in HVDC converter station,as well as the renovation of hidden trouble equipment.