LCL滤波器无源阻尼和有源阻尼对多逆变器并网谐振影响对比分析

Comparative Analysis on Influence of Passive Damping and Active Damping of LCL Filter on Multi － inverter Grid － connected Ｒesonance

摘要:

多并网逆变器系统谐振是由滤波器输出谐波与电网谐波共同作用的结果。LCL滤波器谐振是滤波器输出谐波的主要因素之一,因此提出LCL滤波器谐振阻尼方法对多并网逆变器系统谐振的影响进行分析。首先,分析多并网逆变器系统谐波交互的机理;其次,建立无源阻尼和有源阻尼的多并网逆变器系统阻抗模型,对比分析2种阻尼方法对低频谐振和超高次谐振的影响;最后,采用3台并网逆变器进行仿真实验验证所提理论的有效性。

Abstract:

The resonance of grid － connected multi － inverter system is the result of the joint action of filter output harmonic and grid harmonic． The resonance of LCL filter is one of the main factors of harmonic output of filter． Therefore，the influence of the resonance damping method of LCL filter on the resonance of grid － connected multi － inverter system is analyzed． Firstly，the mechanism of harmonic interaction in grid － connected multi － inverter system is analyzed． Secondly，the impedance model of grid － connected multi － inverter system with passive damping and active damping is established． Then，the influence of two damping methods on low frequency resonance and supraharmonic resonance is compared and analyzed． Finally，3 grid － connected inverters are used for simulation experiment to verify the effectiveness of the above － mentioned theory．