The Research On Several Control Strategy Of Three-phase Photovoltaic Grid-connected Inverter

Energy problem has become an issue of great concern to all countries,every country in the world is now faced with the problem of energy shortage.In the development and utilization of new energy,which has a low-carbon environment clean energy solar energy around the world competing to become the object of intense research.Solar PV is an important form of solar energy utilization,is the use of solar energy is converted to electricity power generation in recent years with advances in power electronics technology,photovoltaic technology will be one of the most promising.This thesis will analysis and research the theory of photovoltaic grid system,quite in-depth research carried out for the main aspects of its hardware circuit,the mathematical model.The design of the three main control strategies were studied: Front grid voltage feed-forward synchronous PI current control strategy,the proportion of quasi-resonant control strategy,direct power grid voltage oriented control strategy,the use of engineering design method before the grid voltage feed synchronous PI current control parameter controls were designed to calculate.Respectively for the above three common control strategies are discussed and adopted the principle of the Matlab simulation was designed after the simulation results are analyzed theoretically,by the above theory content designed and built a three-phase solar photovoltaic grid-connected inverter system,the main circuit structure using a three-phase half-bridge inverter circuit structure,power switching devices produced PM100CL1A120 select Mitsubishi intelligent power module as the power switching device,and the network side of the filter structure using L-type,the overall system is simple and easy to achieve,control STM32F407IGT6 type ARM-based systems from the control panel and LEM voltage and current sensors and other components,control system implementation capabilities for signal acquisition and processing and network control algorithm written in three-phase SPLL,MPPT control and network switching and other functions.On the experimental platform based on experimentally validated before the grid voltage feed synchronous PI current control strategy to achieve the desired results of the design goals,has been more good experimental results.Ultimately,for the design of photovoltaic grid system was conclusive generalization,and envisages the organization of work proposed for the follow-up work,etc.