基于并联电容参数识别的VSC-HVDC输电线路纵联保护  

Pilot Protection for VSC-HVDC Transmission Lines Based on Shunt Capacitance Parameter Identification

作　　者：宋国兵[1] 靳幸福[1] 冉孟兵[1] 高淑萍[2] 索南加乐[1] 

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049 [2]西安科技大学电气与控制工程学院,陕西省西安市710054

出　　处：《电力系统自动化》2013年第15期76-82,102,共8页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51037005;51177128);教育部博士点基金资助项目(20110201110056)~~

摘　　要：电压源换流器型高压直流(VSC-HVDC)输电线路两端并联有大电容,在故障发生瞬间,大电容迅速向故障点放电,对高频故障分量系统侧可等效为并联大电容。根据VSC-HVDC这种特有的系统结构,提出了一种基于并联电容参数识别的VSC-HVDC输电线路纵联保护新原理。该保护原理采用时域算法,通过识别VSC-HVDC输电线路两侧的电容值来区分区内、区外故障。当直流输电线路发生区内故障时,能同时准确识别出线路两端的电容值;当直流输电线路发生区外故障时,不能同时准确识别出线路两端电容值。根据此特征,构造纵联保护判据。理论分析和仿真结果表明,该原理不受过渡电阻、故障类型、故障位置、控制方式和线路类型的影响,在各种工况下均能快速可靠地区分区内、区外故障,而且该方法计算简单,易于实现,具有一定的实用价值。The shunt large capacitances on both sides of voltage source converter based high voltage direct current（VSC-HVDC） transmission lines,will rapidly discharge to the fault point when a fault occurs,and the system side reactance can be equivalent to the shunt large capacitance in the model of high frequency fault component.According to this characteristic of VSC-HVDC system,a novel principle of pilot protection for VSC-HVDC transmission lines based on shunt capacitance parameter identification method is proposed.The protection principle using time-domain algorithm can distinguish internal and external faults by identifying the capacitance parameters at both ends of transmission line.The capacitances at both ends can be accurately identified simultaneously when an internal single pole ground fault occurs.But the capacitances at both ends cannot be accurately identified simultaneously when an external fault occurs.According to this characteristic,a pilot protection criterion is constructed.The theory analysis and simulation results show that the method is not affected by transition resistance,fault type,fault location,control mode and line type,and it can identify internal faults and external faults reliably and rapidly in various situation.In addition,the method can be implemented easily with simple computation,having certain practical value.

关 键 词：电压源换流器型高压直流 直流输电线路 参数识别 纵联保护 故障分量 

分 类 号：TM773[电气工程—电力系统及自动化]