Abstract：The no-load closing of the high-voltage built-in high-impedance transformer will produce a zero-sequence inrush with high amplitude and slow decay, which will easily cause the misoperation of the zero-sequence IV protection of the line and the whole station to lose voltage in the 220kV substation. At present, there is no literature to propose a corresponding solution. A line zero-sequence IV protection based on amplitude-integration comparison blocking is proposed. The blocking method constructs the blocking curve by using the attenuation characteristic of the zero-sequence inrush. Through the integral comparison of the actual zero-sequence current amplitude curve and the blocking curve, the protection is reliably blocked in the case of zero sequence inrush and can reliably act under the ground fault condition. Moreover, the operation threshold of the blocking criterion is a linear function of the actual zero-sequence current waveform data, which is a floating threshold, without being affected by factors such as voltage closing angle, main transformer remanence, and system operation mode, meaning the blocking criterion has universal applicability.
肖硕霜, 晋龙兴, 王世祥. 基于幅值积分比较闭锁的线路零序IV段保护方法[J]. 电气技术, 2020, 21(2): 56-59.
Xiao Shuoshuang, Jin Longxing, Wang Shixiang. Line zero-sequence IV segment protection based on amplitude score comparison. Electrical Engineering, 2020, 21(2): 56-59.
2020, Vol. 21 
