Grid-connected Photovoltaic Systems Power Generation Systems Based On The Quasi-Z Source Inverter

Energy is the ladder of the progress of human society, so to realize the sustainable development of human society to solve the increasingly serious energy crisis in the first place.Traditional fossil fuels because irrefragable increasingly in danger of drying up, and the application of a series of environmental problems, so it can predict the future will be replaced by new sources of energy. Compared with other energy, solar energy green environmental protection, cheap and plentiful, unlimited, so the development and utilization of solar energy has become an important strategic decision for the sustainable development of many countries in the world, and photovoltaic power generation as a way of using solar energy, with its unique advantage has been widely used.However photovoltaic grid power generation also exist some obvious deficiencies, such as the volume of the inverter is too large, the system cost is high, the start impact current is big, filter resonant, etc, so the key to solve these problems become a photovoltaic power generation technology application. First of all, this paper introduces two kinds of commonly used grid inverter, the voltage type inverter and the current type inverter, although the two can achieve photovoltaic grid inverter, but there are a lot of shortcomings, for its shortage, put forward in recent years the Z source inverter is very good solution to the shortage of the traditional inverter, but Z source inverter also there is insufficient, therefore some scholars in the Z source inverter is proposed on the basis of Quasi-Z source inverter, this paper analyzes the working principle of the Quasi-Z source inverter and the relative advantages of Z source inverter.Second, in the static coordinate system to establish the mathematical model of three-phase grid inverter, through coordinate transform the static coordinate system of three-phase symmetrical communication quantity for synchronous coordinates straight flow, current astatic control was achieved by PI regulator, also realizes the decoupling control of active and reactive power.In addition is analyzed based on the basic principle of voltage oriented vector control and deficiency, based on this. advances an improved virtual flux vector control.Finally in the Matlab/Simulink to build simulation module and simulation, validation theory is feasible...