The grid-connected inverter with LCL filter in the distributed power generation system (DPGS) has the ability of attenuating high frequency current harmonics. However

the resonance of LCL filter will lead to instability of the system. In order to avoid stability problems

some active damping techniques for voltage or current feedback are adopted. But these methods need extra sensors and increase control complexity. A notch filter provides an effective solution and can ensure the stability. A new designed notch filter is proposed to neutralize the resonance of LCL filter and a proportional-integral (PI) controller is employed to increase the gain of fundamental frequency for reducing steady-state errors and improving the dynamic response. The analysis is validated by simulation and experiment. This work is supported by National Natural Science Foundation of China (No. 61473145)

Jiangsu Provincial Graduate Education Innovation Project (No. KYLX_0279) and Fundamental Research Funds for the Central Universities.