基于故障电压序分量的超高压线路T接测距新算法

Fault locating based on fault voltage sequence components for T -type connection EHV lines

提出了一种基于集中参数线路模型的高压/超高压T接线路测距新算法。该算法在考虑线路分布电容的前提下,仅采用故障电压序分量进行故障测距,具有不受故障后电流互感器饱和影响的优点。对于对称类故障,用电压正序故障分量进行测距;对于非对称类故障,用电压负序故障分量进行测距。对该算法分别就单回线-单回线T接线路、单回线-双回线T接线路、双回线-双回线T接线路接线方式下测距做了详细讨论,并提出了新的故障分支判据,依次计算每个分支的故障距离,比较后即可准确判断故障分支。ATP仿真验证表明,对于三端同步及不同步采样电压量数据,测距精度都在1%以内。

A fault locating algorithm based on the transmission line model with lumped parameters is presented for HV / EHV T- type connection transmission lines,which considers the distributed capacitance of lines and uses the sequence components of fault voltage in fault locating to avoid the influence of saturated CT after fault. Positive sequence component of fault voltage is used for symmetric faults and negative sequence component for non-symmetric faults. Different conditions are discussed in detail：single-line to single-line T-type connection,single-line to parallel-line T-type connection and parallel- line to parallel- line T- type connection. A new faulty branch criterion is proposed. The fault distance of each branch is calculated and compared to accurately determine which the faulty one is. ATP simulation indicates that the locating precision is within 1% with the synchronously or asynchronously sampled voltages at three terminals.