利用两端电气量实现T型高压线路相间故障定位方法

采用分布参数建模，提出了一种利用2端电气量实现T型高压线路相间故障定位的方法。该方法利用保护测量到的电气量计算故障点电压，并在此基础上构造了故障定位函数，根据故障定位函数相位特性判断故障支路。在故障支路的故障点前后变化时，故障定位函数相位会发生唯一1次突变，相位突变点所对应位置即为故障点。采用分布参数建模，克服了分布电容的影响；算法设计中考虑了故障电压的影响，克服了负荷电流的影响；利用故障定位函数相位突变特性进行定位，克服了过渡电阻的影响。PSCAD /EMTDC仿真结果表明，该方法受故障位置、过渡电阻和负荷电流的影响很小，具有很高的测距精度。

New Location Method for Phase-to-phase Fault on Three-terminal HV Transmission Line Using Electric Data at Terminals

Based on distributed parameters, a new location method is presented for phase-to-phase fault on three-terminal HV transmission line by using electric data at terminals. The fault voltage is calculated by the voltage and current data measured from the protection. The fault location function is provided, of which the phase characteristics are applied to decide the fault section. The only step point for the phase of fault location function corresponds to the fault position. As a result, the method avoids the distributed capacity effect by modeling with distributed parameters, the load current effect by considering fault voltage, and the transition impedance effect by phase step of fault location function. It is shown from the simulation by PSCAD/EMTDC that the method is of high range accuracy, regardless of fault location, transition impedance and load current.