EMTR理论在电力系统线路故障测距中的应用基础Ⅱ:仿真部分

Application Basis of EMTR Theory for Line Fault Location in Power System Ⅱ: Simulation Part

根据基于电磁时间反转(electromagnetic time reversal,EMTR)的线路故障测距理论部分,可得到3种不同的故障测距方法,分别为时域电流法、频域前行电流法和频域前行电流补偿法。时域电流法仅利用线路两侧的故障电流分解量,在时域中求无损镜像线路中的假设故障电流有效值最大处;频域前行电流法利用单一参数线路两侧的频域暂态前行电流的共轭量,在有损镜像线路中求得假设故障电流有效值最小处;频域前行电流补偿法利用线路两侧频域暂态前行电流的共轭量,在无损镜像线路中求得假设故障电流有效值最大处,再利用故障距离偏差数据库对故障距离进行补偿。建立了双端交流输电系统(包括单一参数线路和混合参数线路),对3种方法进行了大量仿真验证。

Three fault-location methods are generated with EMTR-based fault location theory,respectively called the method of current in time domain,the method of forward current in frequency domain,and the method of forward current in frequency domain with compensation.The first method utilizes the decomposed transient currents in time-domain to calculate the RMS values of assumed fault current in lossless mirror line and select the peak value from all RMS values.The second method uses the forward current in frequency domain to calculate the RMS values of assumed fault current in lossy mirror line and select the smallest RMS values.The third method calculate the RMS values of assumed fault current in lossless mirror line and select the peak value from those values,and the final fault location is compensated with the pre-calculated errors of fault location.A two-terminal AC transmission system is established for testing these three methods,and the single and mixed parameter lines are respectively taken into the simulated system for large amount of tests.