微电网中电压型逆变器滤波器研究

Research on Filter of Voltage Inverter in Microgrid

微电网并网电流谐波问题一直是研究热点。目前主要采用LC型滤波器来抑制电流谐波。LCL型滤波器结构上只比LC型滤波器增加了一个电感,但应用于电压型逆变器其谐波抑制效果更加明显,并且控制策略有着明显区别。此外,LCL滤波器又存在谐振频率出易发生谐振问题。通过无源阻尼法和有源阻尼法研究LCL滤波器的谐振抑制问题和通过计算选取参数比较2种滤波器的谐波抑制能力。得出了LCL滤波器使用阻尼法的谐波抑制能力高于LC型滤波器。

Grid current harmonics of micro-grid has been the research focus. At present, the LC filters are used to suppress current harmonics. LCL filter only increases one inductor than LC filter on the structure, but the harmonic suppression effect is more obvious, and there is a clear difference between the control strategies when applied in voltage inverter. In addition, LCL filters are easy to resonate at resonant frequeney. In this paper, passive and active damping methods are used to research on the problem of resonance suppression in LCL filters and through comparison parameters to calculate the harmonic suppression of two kinds of filter. It is obtained that LCL filters with damping methods have better ability of suppressing current harmonics than LC filter.