并网逆变器LCL型滤波器的设计及有源补偿

Design and Active Compensation of LCL Filter for Grid-Connected Inverter

在并网逆变系统中,LCL型输出滤波器能够很好地抑制功率开关管高频开通与关断产生的大量高次谐波,因此备受关注。针对LCL型输出滤波器,阐述了滤波器电感L及电容C参数取值原则及设计步骤。由于LCL输出滤波器是三阶系统,易引起输出振荡,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1.5 kVA单相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 high frequency switching on and off. The design criterion and calculation procedures of LCL were introduced in detail But the LCL filter is a third order system, which means it is easy to resonate. In order to increase the damping and eliminate the resonance of LCL filter, a method with filter capacitor current feedback was adopted. All the theoretical analysis was verified by experimental results on a single phase 1.5 KVA grid-connected inverters with an LCL filter.