Research Of Distributed Photovoltaic Micro Inverter Control And Modulation Strategy

With increasingly decrease of the fossil energy and environmental pollution,people's demand for renewable energy increases fast.Among the various kinds of renewable energy such as solar,wind and bioenergy,solar with the abundant,easy to obtain,pollution free characters receives people's favor.In the commercial electric power market,photovoltaic power generation system is applied more and more widely and it prompts its rapid development.As the core part of the photovoltaic power generation system,the choices of photovoltaic grid-connected inverter's topology,control strategy and modulation strategy are closely related to the performance of photovoltaic power generation system.Suitable control and modulation strategy can improve the electric power quality.This paper firstly illustrates basic principles of photovoltaic power generation system,and at the same time introduces the commonly used control and modulation strategy like feedback linearization,SPWM and so on.Especially,it emphasizes analysis and discussion of feedback linearization technology.Then,it determines Boost circuit and full bridge circuit as the research objects.Furthermore,it puts up two-stage photovoltaic inverter simulation model of different control and modulation strategy,and then verifies the control and modulation strategy which have been mentioned above.The simulation result indicates that at the same power level,THD of modified SPWM modulation strategy is much less than it of SPWM modulation strategy.Comparing modified SPWM modulation strategy based on feedback linearization control strategy with modified SPWM modulation strategy based on PI regulation,the response speed and steady precision of former one are much better.