The analysis shows that the measured impedance at the head of the line is not proportional to the fault distance when a three-phase fault occurs at the end of the line.
分析表明，线路末端三相故障时，线路首端的测量阻抗不与故障距离成正比。
2
Because the impedancefault location method is easily influenced by the factor such as fault resistance, transformer error and asymmetrical line configuration, the fault location accuracy is lower.
由于阻抗法易受过渡电阻、互感器误差、线路结构不对称等因素的影响，所以测距精度不高。
3
Especially it solves the identification problem of high impedancefault well.