基于回路模态分析法的串联谐波谐振评估

串联谐波谐振发生时会造成系统过电压,损坏电力设备,影响系统正常工作。为了解决此问题,需获得准确的串联谐波谐振频率,从而控制谐波源产生与此相应的谐波。由于串联谐振的发生与回路密切相关,不能用节点阻抗矩阵来分析串联谐振问题,据此提出一种分析网络回路阻抗矩阵以获得串联谐振频率及相关支路信息的模态分析方法。仿真分析所得串联谐波谐振频率与频谱分析的比较结果证明此方法正确。理论分析和算例研究证明,该方法是电力系统谐波谐振分析的有效工具。

A Loop Modal Analysis Method for Series Harmonic Resonance Assessment

Under the effect of harmonic,series resonance and parallel resonance may occur in the local circuit of electric power system. Parallel resonance and series resonance are the two important parts of harmonic resonance problem. Although parallel resonance accounts for the highest proportion in the power system,series resonance's harm is also noticeable. When series harmonic resonance occurs,it will bring about system overvoltage and damage the power equipment. In order to solve this problem,it is necessary to get the exact frequency of the series harmonic resonance,so that the harmonic generated by harmonic source can be controlled. Due to the affinity between series resonance and loop,series resonance problem can not be solved by analyzing node impedance matrix. This paper first analyzed the characteristics of series resonance,then proposed a mode analysis method to obtain series harmonic resonance frequency and corresponding branch information through analyzing loop impedance matrix. Compared with the frequency scan analysis,it demonstrates the series harmonic resonance frequency obtained by using the method proposed in this paper for simulation is correct. Analytical and case study results have confirmed that the proposed method is a valuable tool for power system harmonic resonance analysis.