Research on DC side power decoupling control of photovoltaic inverters

Abstract

Inverter is a vital component in photovoltaic power generation system, and it is related to the performance and efficiency of photovoltaic power generation. When the inverter is connected to the grid, the instantaneous power on the DC side and the AC side is unbalanced, and the instantaneous power pulsation of double frequency will be generated on the DC side, which directly affects the current stability and power utilization rate of the inverter on the DC side. This paper proposes a Power Decoupling Circuit (PDC) based on a single-phase photovoltaic inverter. This circuit uses a closed-loop feedforward power decoupling control strategy to compensate for the unbalanced pulsating power on both sides of the inverter. Eliminate low-frequency harmonics on the DC side, achieve the purpose of power decoupling, stabilize the DC side voltage of the photovoltaic inverter, and improve the performance and efficiency of photovoltaic power generation.