直流换流站出口L-C型辅助防雷滤波装置

为降低直流输电线路遭受雷击后在换流站设备上产生的过电压,对高频谐波进行抑制,提出在±500 kV换流站出口处加装一组L-C型辅助防雷滤波装置.首先,分析了L-C型辅助防雷滤波装置的结构原理和防雷保护特性,并对其进行参数选取.其次,研究了直流侧进线段和换流站各设备的建模方法,在PSCAD/EMTDC中搭建±500 kV换流站直流侧雷电过电压模型进行仿真分析,仿真结果验证了所提方法的有效性和可行性.最后,针对算例分析了雷击故障和换流站直流母线短路这两种情况,提出应该对L-C型辅助防雷滤波装置采用一定的保护措施,以确保其安全.

Study of L-C Type Auxiliary Device at the Bus of DC Converter Station for Lightning Protection and Harmonics Filtering

In order to reduce the overvoltage generated on the converter station equipment after a lightning striking on the HVDC transmission line and suppress the extra-high frequency harmonics, a L-C type auxiliary device was proposed to install at the HVDC bus of the ±500 kV converter station. The structure and the lightning protection characteristics of the auxiliary device were analyzed with parameters selected. Then the DC side incoming transmission line and equipment at the converter station were modeled. In the PSCAD/EMTDC, a lightning source was added at the DC side of a ±500 kV converter station. The simulation results prove that the auxiliary device at the HVDC bus of the DC converter station is effective to limit the lighting overvoltage and high frequency harmonics. Finally, the characteristics of the auxiliary device under lightning strike and a DC bus short circuit fault were analyzed, and the corresponding protection schemes were proposed to ensure the reliable operation of the auxiliary device.