Research on fuzzy control based distributed photovoltaic grid-connected active support scheme

With the rapid growth of distributed photovoltaic (PV) installed capacity, traditional distribution networks face many challenges in the process of transitioning to active distribution networks. In this paper, a study is carried out on the grid connection of PV inverters, focusing on analyzing their grid connection characteristics and the deficiencies of existing control strategies, such as the steady state fluctuation and control speed problems of MPPT technology. On this basis, an active support scheme based on joint reactive and active voltage regulation is proposed, where the inverter can adaptively adjust the active and reactive outputs according to the grid voltage state. In addition, fuzzy control techniques are introduced for the adaptive tuning of the PI parameters of the voltage loop of the Boost circuit as well as the automatic adjustment of the control step of the active power curtailment, thus enhancing the control performance. The proposed method’s effectiveness is validated through a simulation model built in MATLAB/Simulink and tested under varying light intensity conditions. The results demonstrate that the approach effectively reduces fluctuations in PV output active power, accelerates active power curtailment, improves voltage regulation capabilities, and achieves a balance between maximizing PV output and managing voltage issues, offering a practical solution for distributed PV grid connection challenges.