基于电压内积的带并联电抗器输电线路单相自适应重合闸

针对带并联电抗器的超高压输电线路,提出一种基于电压内积的单相自适应重合闸实现方案。在线路发生单相接地故障且故障相两端断路器跳开后,求出健全相电压和与故障相端电压的内积为始化内积,健全相电压和与故障相端电压一阶导数电压的内积为补偿内积。对于永久性故障,经短暂态后,始化内积小于补偿内积,两内积曲线不会出现交点。对于瞬时性故障,在二次电弧初始阶段,始化内积小于补偿内积;随着电弧电阻增加,始化内积逐渐增加,补偿内积逐渐减小,两内积曲线出现交点;在恢复电压阶段,两内积呈低频振荡曲线且相位相差90°,并相互交错再次出现交点。基于上述现象,通过两内积曲线是否出现交点来区别永久性和瞬时性故障,并当出现第二个交点时可以确定瞬时性故障已进入恢复电压阶段。该方法不需要整定,在断路器单相跳开后启动判据,实现简便,不需要频域计算、不受低频振荡分量的影响。EMTP仿真和实际录波数据验证了其正确性和可行性。

A Voltage Inner Product Based Approach for Single-Phase Adaptive Reclosure on Transmission Line with Shunt Reactors

In this paper, a single phase adaptive reclosure method for high voltage (HV) transmission lines with shunt reactors which based on inner products of voltage is proposed.Healthy phases voltage and fault phase voltage inner product are treated as initialization inner product, inner products of healthy phase voltage and derivative of fault phase voltage as compensation inner product when single-phase grounding fault appear and the fault phase ends of circuit breaker tripping.To permanent fault, the initialization inner product will keep smaller than compensation inner product in a short transient state, therefore, two inner product curve won't appear intersection.As for transient fault, in the second arc initial stage, the initialization inner product is smaller than the compensation inner product;with the increase of arc resistance, the initialization inner product increase while the compensation inner product decrease, they would have a point of intersection.After arc extinction, low-frequency oscillation is observed in two curves of voltage inner products which have 90° phase differences;they would also have points of intersection.According to this phenomenon, the point of intersection of voltage inner products are used to identify permanent and transient faults and to determine the transient fault has entered the stage of recovery voltage when the second intersection appears.The proposed algorithm needs no threshold which can easily operate and start when the circuit breaker single-phase tripping appears.It does not need to be calculated in frequency domain and not affected by low frequency oscillation component.The EMTP simulations and field data verified its correctness and effectiveness.