Design of 1KW Single-Stage Photovoltaic Grid-Connected Generation System

Abstract

The small power photovoltaic(PV) grid-connected generation system with two-stage structure has a shortcoming that is low efficiency, the paper designs a 1kW PV grid-connected generation system with single-stage structure, and designs bus bar capacitance's parameter and filter's parameters. The system with single-stage structure must not only control bus bar voltage, but also control grid-connected current, however, single loop control cannot satisfy demand So the paper adopts double loop control strategy to realize grid-connected, and builds mathematical models for grid-connected current inter-loop and voltage outer-loop respectively. The simulation results with Simulink software show that inverter's output grid-connected current can track the grid voltage exactly, the system can connect to the grid with high efficiency.