| With the development of modern industry,the global energy crisis and air pollution problems have become increasingly serious and solar energy as an ideal renewable energy has been the attention of many countries.In recent decades,the photovoltaic use of solar energy is rapidly developing;Grid-connected inverter is the core component of the photovoltaic grid.This paper takes the photovoltaic grid-connected inverter system as the research object,deeply studies the topology structure of the inverter,the control strategy,the maximum power point tracking,and on this basis,designs a 1KW inverter prototype.The main contents are as follows: Firstly,the principle of maximum power tracking for wide power generation and battery characteristics are introduced in detail to build a simulation model for photovoltaic cells.The maximum power point tracking simulation experiment in this paper adopts interference observation method,and completes the modeling and simulation of interference observation method..Then two-level micro grid-connected inverter topology,basic working principle,modulation method,voltage and current double closed-loop control strategy;simulation with MATLAB,verify the accuracy of the algorithm;elaborated the design of the hardware circuit and software The control flow includes the power-on procedure,sampling procedure,etc.;the MC56F8013 DSP is used as the central controller to set up the hardware circuit,and experiments are carried out on the two-stage micro grid-connected inverter and its control method.The experimental results verify the control scheme of the two-level micro grid-connected inverter designed in this paper and the correctness of the theoretical analysis.The test results show that the use of current inner loop hysteresis control can make the two-level micro grid-connected inverter achieve fast current follow-up,fast dynamic response and excellent control characteristics. |
