Two-stage Photovoltaic Power Supply Modeling and Simulation Based on Double Closed-loop Control

Abstract

In order to study the operating characteristics of distributed power supply, a photovoltaic power supply model that satisfies grid-connected standards needs to be built first. In this paper, for the two-stage photovoltaic power supply, we first set up the mathematical model of the inverter in the abc coordinate system based on its topological structure. In order to solve the problem that the variables are all of the power frequency AC, the dq rotation coordinate system is transformed; in order to realize the decoupling control, the feedforward compensation is introduced. Then, the mathematical model of the inverter in the complex frequency domain is obtained through Laplace transformation, and then a two-stage photovoltaic power supply model based on double closed-loop control is established. Finally, the RTDS real-time digital simulation platform is used to simulate and analyze the important indicators under normal operation and fault conditions. The results prove that the two-stage photovoltaic power supply model mentioned in this paper satisfies the grid-connected photovoltaic power supply standards and can be applied to the analysis and application of engineering projects.