Research On Control Of Photovoltaic Power Generation System Based On Virtual Synchronous Generator Technology

With the rapid development of social economy and culture, human being is consuming a lot of fossil energy, coal, oil, natural gas and other non-renewable energy is about to run out of. The energy crisis and the ecological environment pollution problems have become increasingly prominent, which makes changing the structure of energy consumption and promoting the development and utilization of renewable energy sources gradually develop into the consensus of government all over the world. Therefore, the development of new energy sources is imminent.With the background of advocating using new energy nationally, and with its characteristics like renewable, non-polluting, and large reserves, solar is making the rise of developing photovoltaic power generation all over the word. As an integral part of photovoltaic power generation system,research on the control algorithms of inverter will have a very important practical significance on application of photovoltaic technology with the continuous development of photovoltaic technology.This paper firstly introduced the background of solar photovoltaic power generation,development status at home and abroad and the development of virtual synchronous generator technology. Secondly, analyzed mathematical model of photovoltaic cell, according to the analysis of the mathematical model to build a simulation model in Matlab / Simulink and carried valid verification of the correctness of the simulation model. Thirdly, described working principle of the preceding stage Boost boost circuit as well as three-phase full-bridge inverter circuit in detail and briefly analyzed several common controlling methods of the tracking of maximum power point, analyzed and compared the advantages and disadvantages, then build a simulation model of MPPT.This key content of this article is based on the traditional principle of droop control, to conduct deep analysis and research of Photovoltaic power system of voltage control type inverter circuit. Analyze the affection of harmonic in the output voltage and current waveforms of the inverter under normal operating conditions and the moment of network, since the system is shocked by current, there is a short sudden increase problem of active output power. We introduced a novel method for improving the droop control based on disturbance observer.Through conducting mathematical model derivation of the improved control strategy, buildingsimulation model in Matlab / Simulink and effectively verifying the correctness of the simulation model.Finally, we set up a hardware platform based on MC56F8346 DSP host controller to verify off-grid and grid load test of Photovoltaic power generation system, including hardware parameters design of main circuit of the system and control circuit, software design of flow chart of the main program and interrupt subroutine.