Research On The Semi-physical Simulation Platform For The Photovotaic Grid-connected Inverter

Photovoltaic grid-connected inverter is the key part of photovoltaic grid-connected power generation system.It can iComplete PV array maximum power point tracking control function and photovoltaic grid connected inverter control function.and make photovoltaic grid-connected generation system more secure and available.Therefore,in order to ensure the stability of power grid and the safety of users,it is necessary to conduct relevant performance tests for photovoltaic grid-connected inverters.Photovoltaic grid-connected inverter field test is expensive,difficult and easy to be restricted by natural conditions such as light and temperature.But the hardware in the loop simulation system is accurate,efficient,cost-savings and can be completed indoors.It is essential to establish a semi-physical simulation platform for photovoltaic grid-connected inverter,and the semi-physical simulation platform is applied to complete performance standard tests of photovoltaic grid-connected inverter.First of all,the working principle of the semi-physical simulation platform for photovoltaic grid-connected inverter is systematically illustrated,and the solution of the semi-physical simulation platform for photovoltaic grid-connected inverter is analyzed in detail.The final design scheme used in this project is determined,and the hardware system and the software simulation are overall designed.Then,the simulation model of photovoltaic grid-connected inverter system is studied in depth.Mainly including: Research on model-building and simulation of the photovoltaic arrays,and the output characteristics of the photovoltaic arrays is analyzed;Research on maximum power point tracking of photovoltaic arrays,and the conductance increment method is applied to maximum power point tracking of photovoltaic array and its related simulation is carried out;Research on topological structure and SVPWM modulation technology of photovoltaic grid-connected inverter;Research on control strategy for photovoltaic grid-connected inverter,and a control strategy based on synchronous PI control for photovoltaic grid-connected inverters is proposed and the control strategysimulation is studied.Finally,based on the in-depth analysis of theoretical analysis and simulation experiments of photovoltaic power generation system,a simulation model of photovoltaic grid-connected inverter system is built under the Matlab/Simulink simulation tool.Using digital signal processor(DSP)to build photovoltaic grid connected inverter controller and with the help of RT-LAB simulation platform,the system simulation model is applied to the semi-physical simulation system,and the semi-physical simulation platform for photovoltaic grid-connected inverter is established.The semi-physical simulation platform finished photovoltaic inverter semi-physical simulation low voltage ride through tests,and the test results indicate that the semi-physical simulation results is accordant with the field test results,which validate the feasibility and accuracy of the semi-physical simulation platform.The establishment of this platform makes the performance standard test of photovoltaic grid-connected inverter can be carried out indoors,which saves the test cost,improves the test efficiency and can complete the performance standard test of photovoltaic grid-connected inverter quickly and conveniently.The semi-physical simulation platform for photovoltaic grid-connected inverter has great significance and good engineering application value.