Research of Multi-inverter Group Control for Photovoltaic Generation Under Partial Shading Conditions

When the photovoltaic array is under weak illumination conditions, the output power is often far less than the rated power of inverters, which makes the power conversion efficiency of the inverters greatly reduced. In order to improve the overall power conversion efficiency of photovoltaic generation, this paper proposes to replace a high-power inverter with several low-power inverters in parallel by group control of multi-inverter. To begin with, different photovoltaic grid-connected topologies and multi-inverter group control strategies are discussed, and an improved multi-inverter equivalent power operation group control strategy is proposed. Then, using the power generation data of a photovoltaic power plant with a capacity of 30kW for half a year, the proposed method was simulated and analyzed. The result shows that the proposed group control strategy can greatly increase the power generation efficiency of photovoltaic plants.