Abstract：Neutral shift protection of ultra high voltage direct current transmission is an important direct current protection after charging the converter transformer and before de-blocking the direct current system. During the direct current system commissioning of Jinbei converter station and Guanggu converter station, the voltage on valve side of converter transformer is abnormal after charging the converter transformer, but the neutral shift protection is not effectively detected, which brings hidden danger for direct current system de-blocking. This paper elaborates the project application of neutral shift protection, Analyses the reasons for the failure of neutral shift protection when the voltage on valve side of converter transformer is abnormal, studies the function and setting value of neutral shift protection, the optimization strategy of neutral shift protection logic, and more reasonable protection setting value suggestions are proposed. Through the real time digital simulation test, when the valve side voltage is abnormal, the optimized strategy can effectively detect and identify, and can improve the reliability of neutral shift protection in engineering application.
罗磊, 艾红杰. 特高压直流输电中性点偏移保护的研究[J]. 电气技术, 2020, 21(11): 71-75.
Luo Lei, Ai Hongjie. Study of neutral shift protection for ultra high voltage direct current. Electrical Engineering, 2020, 21(11): 71-75.
2020, Vol. 21 
