特高压直流单极接地故障时极间耦合电压对顺控逻辑的影响  

Influence of Coupling Voltage on Sequential Control Logic During UHVDC Unipolar Grounding Fault

作　　者：张春亮 宋佳信 ZHANG Chunliang;SONG Jiaxin(State Grid East Inner Mongolia Electric Power Co.,Ltd.,Hohhot 010010,China;State Grid East Inner Mongolia Ultra High Voltage Company,Xilinhot 026000,China)

机构地区：[1]国网内蒙古东部电力公司,呼和浩特010010 [2]国网内蒙古东部电力有限公司内蒙古超特高压分公司,内蒙古锡林浩特026000

出　　处：《内蒙古电力技术》2025年第1期90-95,共6页Inner Mongolia Electric Power

摘　　要：针对某特高压直流输电系统在单极接地故障极隔离过程中双极保护误动作问题进行分析,指出故障极在极隔离时由于线路耦合,受在运极影响产生感应电压,造成分中性母线高速接地开关电压判据不满足,无法执行分闸命令,站内接地极过流保护动作闭锁在运极。为此,建立特高压直流输电线路模型,分析故障时的直流电压电流波形特征。通过分析可知,故障极感应电压大小与运行极电压大小呈正相关,方向与运行极电压方向相同。针对中性母线开关故障顺控操作中故障极线路耦合电压引起双极闭锁的问题,可以通过修改控制判据的方式规避。The paper makes analysis of bipolar protection misoperation occurred in the process of unipolar fault pole isolation in a Ultra⁃High Voltage Direct Current(UHVDC)transmission system.It is pointed out that when the fault pole is isolated from the line,due to the coupling of the line,the induced voltage is generated by the influence of the operating pole,which makes the voltage criterion of the neutral bus high⁃speed grounding switch cannot meet the requirements,and the disconnection command cannot be executed.The overcurrent protection action of the grounding pole in the station is locked at the operating pole.In this paper,a UHVDC transmission line model is established,the waveform characteristics of DC voltage and current during the faults are analyzed.It is derived that the magnitude of the induced voltage at the fault pole is positively correlated with the magnitude of the operating pole voltage,and the direction is the same as that of the operating pole voltage.The problem of bipolar interlocking caused by the coupling voltage of the fault pole line in the sequential control operation of neutral busbar switch faults can be avoided by modifying the control criteria.

关 键 词：特高压直流系统 中性母线开关 直流控制保护系统 单极接地故障 耦合电压 

分 类 号：TM721.1[电气工程—电力系统及自动化]