电力系统铁磁谐振消谐方法研究

Research on Harmonic Elimination of Power System Ferroresonance

铁磁谐振的发生导致绝缘事故、设备损坏,影响电网安全运行,为此,需要对铁磁谐振和消谐方法研究。常规方法是在PT二次侧开口三角两端接阻尼电阻,这样可能存在电阻容量不满足要求和影响继电保护的缺点。本文改进了该方法,提出瞬时零阻抗消谐法。利用Matlab/Simulink建立铁磁谐振系统模型,对瞬时零阻抗消谐法仿真验证,结果表明:(1)单相接地故障引起的铁磁谐振性质与线路的长度和故障切除时刻有关;(2)仿真结果表明瞬时零阻抗消谐法能够有效消除系统中发生的铁磁谐振。

Ferroresonance leads to insulation failure,equipment damage and potential risk to the network. In order to prevent accidents above, it is necessary to do some research on ferromagnetic resonance and measures to eliminate harmonic.The conventional method is connecting damping resistor to PT secondary side, but this may result in the disadvantage that the capability of resistor doesn＇t meet requirements and relay protection may be affected. In this article, a better method to eliminate harmonic with instant zero impedance is proposed. To simulate and verify the method, a ferromagnetic resonance model is built.The conclusions are as follows. First, single-phase earth fault caused by ferromagnetic resonance properties is associated with line length and fault removal time. Second, the ferromagnetic resonance in the system can be effectively eliminated by instant zero impedance harmonic elimination method.