Research on Harmonic Compensation Control Strategy Considering Capacity Limitation of PV Grid-connected Inverter

In this paper, a harmonic compensation control strategy based on a PV inverter is proposed to implement in PV inverter with active filtering functions. In addition, the strategy considers the capacity limitation of the inverter, simplifies the control system design, and optimizes the implementation of a PV grid-connected inverter with an integrated active filtering function. Firstly, the theoretical basis for the integration of active filtering function in PV grid-connected inverters is clarified, and the performance differences of different harmonic detection methods and the tracking performance differences between quasi proportional resonant (QPR) control and vector resonant (VR) control for specific harmonics are compared and analyzed. Secondly, the harmonic compensation strategy considering the inverter capacity limit is proposed for the problem of inverter capacity exceeding the limit, and the command current synthesis method and the control loop design scheme are further proposed. The proposed harmonic compensation strategy effectively suppresses harmonics while ensuring the safe and stable operation of the inverter. Finally, the effect of the proposed harmonic compensation control strategy on harmonic current suppression is verified by simulation in Matlab/Simulink, and the simulation results prove the effectiveness of the proposed control strategy.