基于参数识别的并联电抗器保护

Shunt Reactor Protection Based on the Parameter Identification

针对目前并联电抗器保护性能的不足,提出了基于参数识别的并联电抗器保护新原理,即通过求取参数L和R,利用并联电抗器内、外部故障时的参数方向关系和阻抗幅值关系来判别故障方向。由于参数L,R和系统频率无关,且该方法为解微分方程法,因此该方法从原理上不受系统频率变化、振荡等影响,且受非周期分量的影响相当小。动模实验验证表明,该方法能克服传统电抗器保护中存在的不足,尤其是能有效地解决在轻微匝间故障时存在的动作死区问题,用该方法实现的保护简单、可靠、动作迅速。

A new shunt reactor protection principle is proposed based on the parameter identification method. The values of resistance and inductance are calculated firstly. Then according to the relationships between the parameter directions and the magnitudes of impedances in the internal and external faults respectively, the direction of faults are determined. Because the values of resistance and inductance are not related to the system frequency, and the method is of differential equation, it is not affected by the system frequency change or oscillations, and the non-periodical components have little influence on the results. Dynamic simulation results demonstrate that the method can overcome the shortcomings of the traditional reactor protection, especially the problem of operating dead zone when internal turn-to-turn fault occurs. The method features simplicity, high reliability and fast reaction speed. This work is supported by the National Natural Science Foundation of China （No. 50677051）, the Key Project of National Science and Technology （No. 2005BA208C） and the Science and Technology Project of Northwest Power Grid Company （No. 07-DD05）.