Abstract：Grid-connected inverter system with LCL filter is a third-ordersystem, which has a gain peak at its resonant frequency, and hence lower stability margin and involved complicated design of current regulators. In order to solve these problems, this paper proposes a novel control strategy with the combination of the grid (or inverter side) current feedback and another state variable feedforward, which can degrade the system order from the third to the first. Therefore, not only the stability margin is enlarged, but also the gain peak is eliminated and the current regulator design is greatly simplified. Besides, additional controls are also developed to attenuate the effects of grid voltage distortion or local load disturbance on the grid current, and the grid current waveforms can be further improved. Theoretical analysis, simulation and experimental results verified the proposition.
白志红, 阮新波, 徐林. 基于LCL滤波器的并网逆变器的控制策略[J]. 电工技术学报, 2011, 26(1增): 118-124.
Bai Zhihong, Ruan Xinbo, Xu Lin. Control Strategies for the Grid-Connected Inverter with LCL Filter. Transactions of China Electrotechnical Society, 2011, 26(1增): 118-124.
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2011, Vol. 26 
