单相并网逆变器输出LCL型滤波器的设计

Design of LCL Filter for Single phase Grid-Connected Inverter

采用PwM方案的并网逆变器，在功率开关管的高频开通与关断时会产生大量的高次谐波，从而给电网注入谐波污染，LCL型输出滤波器能够很好的抑制高频谐波，因而备受关注。本文首先阐述了LCL型滤波器电感L及电容C参数取值原则及设计步骤。针对LCL型滤波器易引起输出振荡的特性，为增大阻尼，消除振荡，详细分析了一种基于电容电流反馈的有源阻尼法。最后通过仿真及一台以DSP2812为核心控制器件的1．5kVA并网逆变器装置对理论分析做了实验验证，实验结果表明了所提设计方法的有效性。

Grid connected inverter with an LCL filter can attenuate high frequency harmonics generated by the pulse width modulatec （PWM）inverter. But LCL filter is a third order system which means it is easy to resonate. In order to damp resonance of LCL filter ,a method with filter capacitor current feedback was proposed in this paper. This paper also introduced the design criterion and calculation procedures of LCL in detail. All the theoret-ical analyses presented in the paper were verified by experimental results on a single phase 1.5 kVA prototype of grid-connected inverters with an LCL filter.