Modeling And Simulation Of Photovoltaic Systems Based On FPG

With the development of power electronic technology,its application in power system is more and more extensive.The scale of power electronic system is increasingly large,the structure is more and more complex,and the frequency also tends to be high-frequency,which puts forward higher requirements for real-time simulation technology,and the rapidity and real-time performance of real-time simulation requires the underlying hardware to have strong computing performance.Field programmable gate array FPGA has excellent parallel computing capability and deep pipelined architecture,which has attracted much attention in recent years,providing a new idea for real-time simulation of power electronic systems.In this paper,the CPU-FPGA co-real-time simulation platform is built with FPGA and CPU as the underlying hardware,and the photovoltaic grid-connected system is taken as an example to verify the co-simulation platform.The specific work of the paper is as follows:(1)The research background of this paper is introduced,and the topological structure of the grid-connected photovoltaic system of the research object is analyzed,as well as the working principle,topological structure and mathematical model of DC/DC converter and DC/AC inverter,which lays a theoretical foundation for the following.(2)The model of photovoltaic grid-connected system is divided into two parts:big step primogeniture system and small step primogeniture system.The small step primogeniture system is the switching high-frequency circuit.An equivalent model of switching high frequency circuit was established by using L/C binary method of switching modeling.The off-line simulation results were compared with Simulink simulation results to verify the effectiveness of the modeling method.In order to reduce the influence of communication errors on simulation accuracy,the equivalent averaging algorithm of high frequency pulse signal and Lagrange interpolation method were proposed to compensate the errors caused by data interaction between the size and step after model segmentation.(3)The real-time simulation algorithm of switching high-frequency circuit based on FPGA is designed.The mathematical model of HDL Coder for switching highfrequency circuit is established by using HDL Coder module library.The HDL Coder tool is used to automatically realize code conversion without manual coding,which improves the working efficiency.(4)The CPU-FPGA co-simulation platform was built,the structure and data interaction mode of the co-simulation platform were analyzed,and the co-simulation platform was verified by photovoltaic grid-connected system.The hardware resource consumption of FPGA before and after optimization was compared,and the results show that the optimized algorithm has a lower hardware resource occupancy rate.It is proved that the co-simulation platform has the advantages of saving hardware resources and improving simulation efficiency.