一种无须求解谐波转移阻抗的分散式多谐波源责任量化方法

A Responsibility Quantification Method of Distributed Multiple Harmonic Sources Without Solving Harmonic Transfer Impedance

现有分散式多谐波源责任量化方法均采用谐波源等值电路(常用诺顿等效模型)的外部端口电流(统称为“谐波源端口电流”)来计算该谐波源对关注母线的谐波贡献度。由于谐波源端口电流受基尔霍夫定律约束,只要电网中某谐波源端口电流发生变化,所有谐波源对关注母线的谐波贡献度会随之改变,但该电流通常是谐波源和背景谐波耦合作用的结果,由此计算的谐波贡献度不能真实反映该谐波源的发射水平。基于此,文中运用谐波源电流本身而非谐波源端口电流来计算谐波贡献度,所提方法直接计算各谐波源对关注母线的谐波电压矢量贡献,而无须求解各谐波源对关注母线的谐波转移阻抗,减少了误差累积效应,可更为公平合理地反映各谐波源责任。仿真和实验算例验证了所提方法的有效性和准确性。

All the existing quantification methods of harmonic responsibility of distributed multiple harmonic sources use the external port current(hereinafter referred to as the harmonic source port current)of the harmonic source equivalent circuit(Norton equivalent model in common use)to calculate the harmonic contribution of the harmonic source to the concerned bus.Since the harmonic source port current is constrained by the Kirchhoff’s law,as long as the harmonic source port current changes in the power grid,the harmonic contributions of all harmonic sources to the concerned bus will change accordingly.However,the harmonic source port current usually is the result of the coupling of harmonic source and background harmonic,so the harmonic contributions calculated by this current cannot truly reflect the harmonic emission level of the harmonic source.Therefore,this paper quantifies the harmonic responsibility of each harmonic source to the concerned bus by harmonic source current itself rather than harmonic source port current.The proposed method directly calculates the complex harmonic voltage contribution of each harmonic source to the concerned bus,and it does not need to solve the harmonic transfer impedance of the harmonic source to the concerned bus,which reduces the effect of cumulative errors and can more fairly and reasonably reflect the harmonic responsibility of each harmonic source.The effectiveness and accuracy of the proposed method are verified by simulation and experimental cases.