基于电压相位波动特征的单相永久性故障识别方法

Identification of single phase permanent fault based on voltage phase fluctuation characteristics

研究了带并联电抗器的超高压输电线路发生单相接地故障时跳开相电压的自由振荡分量频率的影响因素,分析了带并联电抗器的超高压输电线路发生单相接地故障时跳开相电压的相位特征,揭示了恢复电压相位周期性波动的原因,并考虑了傅氏算法处理含非基频量信号时的误差对跳开相电压相位计算的影响。引入健全相电压相量和作为极化电压,以极化电压为基准区分发生瞬时性故障与永久性故障时的跳开相电压相位,提出了识别永久性故障的跳开相电压相位波动判据。EMTP仿真结果表明,该判据计算简单,判定准确,且不受过渡电阻影响,可有效适用于带并联电抗器的输电线路单相故障性质的识别。

The factors affecting the frequency of the free oscillation component of the tripping phase voltage when a single-phase grounding fault occurs in an EHV transmission line with shunt reactors are studied. The phase characteristics of the tripping phase voltage during transient single-phase grounding fault of EHV transmission line with shunt reactors are analyzed,and the reason for the phase periodic fluctuation of recovery voltage is revealed. With the consideration of the influence of the error of Fourier algorithm when processing the signals with non-based frequency components on tripping phase voltage calculation,the sum of healthy phase voltages is introduced as the polarization voltage,the phases of tripping phase voltage in transient faults and permanent faults are differentiated based on the polarization voltage,and a criterion of phase fluctuation of tripping phase to identify permanent faults is proposed.EMTP simulation shows that the proposed criterion is simple,accurate and immune to the transition resistance,and can be effectively applied to the fault nature identification of single-phase adaptive reclosing of EHV/UHV transmission lines with shunt reactors.