高压直流换流器差动保护抗干扰性能研究

以高压直流换流器差动保护干扰故障为例，详细分析故障发生过程、原因和改进措施。通过对故障录波进行深入的分析，深入研究换流器保护原理和抗干扰性能，发现高压直流母线测量信号波形畸变是引起保护误动的主要原因。提出将换流器差动保护延时功能由快充慢放的积分模式更改为固定延时方式来提高保护可靠性。数字仿真和现场运行验证改进后保护性能满足运行要求。

Study on Anti-jamming Performance of Differential Protection in HVDC Converter

A differential protection fault of an HVDC converter is analyzed in detail, including the course and cause of fault and the improvement measures. The analysis of the fault record and further study on the protection principle and anti-jamming performance of the converter show that the main cause of protection mis-operation is distortion of measurement signal wave of the HVDC bus. It is proposed that the delay function of the converter differential protection should be changed from the integral mode to fixed time delay mode, so as to improve the reliability of the protection. The digital simulation and field test validated that the improvement of the protection meets the operational requirements.