Research and Application of Current Output Type Additional Controller in Photovoltaic Grid-connected Power Generation System

Aiming at the undesirable distribution network dynamic processes caused by the access of distributed generations, electric vehicles, and distributed energy storage systems, this paper proposes a current output type additional controller for improving the dynamic characteristics of the distribution network. Firstly, this paper models the photovoltaic grid-connected system and then describes the principle of the additional controller based on the model. The proposed current output type additional controller mainly fine-tunes the inverter sampling loop current by outputting three-phase additional control current to improve system stability. Secondly, the proposed additional controller is simulated and verified based on the photovoltaic grid-connected system. Finally, according to the coupling condition of the current sampling loop of the inverter control unit, the hardware circuit of the output current source of the additional controller is designed and implemented.