基于时变相量的配电网PT铁磁谐振研究与措施分析

The Study on ferroresonance and measure analysis of distributed network based on time-dependent vector theory

利用相模变换理论,建立了配电网发生绝缘放电时的故障分析模型,分析了配电网PT发生铁磁谐振的原因及稳态谐振的发生机理.根据系统的0模网络的ΔI(φL)曲线提出了加装零序PT抑制铁磁谐振的方法,以避免系统发生工频铁磁谐振.

The model of ungrounded neutral distributed power system for ferroresonance analysis is established by employing phase-mode transform. Based on the time-various phasor theorem, the time various phasor model of nonlinear resonance is established as well. The reason causeing to the steady resonance is that there exists more than one steady state point. The ultimate working point depends on the disturbance size. Finally, the harmonic elimination measure of adding 0-mode PT is analyzed according to the curve of△Ⅰ（φL） and the efficient condition of elimination power harmonic measure is put forward.