Active Damping Method Based on State-Feedback for Grid-Connected Inverter with LCL Filter
Zhang Qi1,2, Li Rui1, Zhang Yongping1, Ren Biying1, Sun Xiangdong1,2
1. Department of Electric Engineering Xi’an University of Technology Xi’an 710048 China;; 2. Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi’an University of Technology Xi’an 710048 China;
Abstract Based on discrete state space model analysis for LCL grid-connected inverter, an active damping method is proposed to settle down the stability problems caused by the grid impedance variation and the digital time delay. The common coupling point voltage vpcc is used as a system state, and its feedback characteristics is studied to reveal its damping effect. In addition, the states feedback characteristics of inverter current ii and grid current ig are evaluated respectively. Consequently, a state reconstruction method is provided, which relies on the sampling values of vpcc and ig. Meanwhile, the order of the space model is virtually enlarged to improve the system stability. The feasibility and effectiveness of the proposed control method are verified by Matlab/Simulink simulations and experiments.
Zhang Qi,Li Rui,Zhang Yongping等. Active Damping Method Based on State-Feedback for Grid-Connected Inverter with LCL Filter[J]. Transactions of China Electrotechnical Society, 2019, 34(8): 1698-1707.
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2019, Vol. 34 
