长距离输电线路中间带并联电抗器的双端非同步故障定位算法

针对线路中间带并联电抗器的长距离输电线路提出了基于双端工频量的非同步故障定位算法。对于等值阻抗固定的并联电抗器,采用故障前的双端相量估计并联电抗器的实际等值阻抗,从而基于故障后正序网络得到故障点位置。对于可控并联电抗器或故障前数据无法获取的情况,还提出了一种与并联电抗器模型无关的故障定位算法,根据不同故障类型的故障边界条件,利用故障点电压电流相位特性构造定位函数,分析表明该函数在相应定位区间具有单调变化特性,因而各定位区间不存在伪根,求解快速。所提算法均基于分布参数模型,双端数据不同步角采用故障前或故障后测量相量进行补偿。基于PSCAD/EMTDC和MATLAB的仿真结果表明,所提方法计算简单、精度高,对不同步角、故障类型、过渡电阻、故障位置均有较好的适用性。

Dual-terminal asynchronous fault location algorithm for long transmission line with shunt reactor in middle

An asynchronous fault location algorithm based on the power-frequency measurements at two terminals is proposed for long transmission line with shunt reactor in middle. For the shunt reactor with fixed equivalent impedance, its equivalent impedance is estimated with the pre-fault phasors of two terminals and the fault is located based on post-fault positive-sequence network. For the controllable shunt reactor or that without pre-fault data, a fault location algorithm irrelative to the shunt reactor model is proposed, which exploits the characteristics of voltage and current phasors at fault point to construct the fault location function according to the boundary conditions of different fault types. Analysis shows that, the fault location function has monotonicity in the corresponding location sections, which means it can be quickly solved because there is no false root in a location section. The proposed algorithms are both based on the distributed-parameter line model and the asynchronous phasor of two terminal data is compensated by pre-or post-fault measurements. The simulative results based on PSCAD/EMTDC and MATLAB show that, the proposed algorithms are simple, accurate and suitable for different asynchronization angles, fault types, fault locations and transition resistances.