In order to improve the efficiency of grid-connected photovoltaic power generation,this paper proposes a three-phase LCL-type grid-connected photovoltaic system based on COOT optimization algorithm and improved repetitive PI control.The improved repetitive PI control is used for the back-stage inverter,and the LCL active damping control is designed through the damping factor,taking the sampling calculation delay and PI control into account in the mathematical modeling process,and finally adding the repetitive control.In order to reduce the odd harmonics,a cascaded repetitive PI control structure is used.At the same time,to address the problem that the control effect of the repetitive control strategy decreases when the grid frequency fluctuates,a method based on the frequency adaptive cascade repetitive PI control based on the Lagrangian interpolation principle is used.Based on the proposed control strategy,the Simulink simulation platform is used to model and simulate the system,and the simulation results show the correctness and feasibility of the proposed control strategy.
维普
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