Research On Novel DC/AC Boost Photovoltaic Converter Without Leakage Current

In recent years,the depletion of fossil fuels and the formulation of new carbon dioxide emission regulations have greatly promoted the world’s attention to distributed renewable energy.Among all kinds of new environmental protection energy,solar energy has become one of the most important environmental protection energy in today’s society,because it has the characteristics of green,pollution-free and unlimited reserves.As the interface between photovoltaic system and load,photovoltaic inverter has become an indispensable part of photovoltaic power generation system.Therefore,the research on high-performance photovoltaic inverter has a very important application value and theoretical significance.Because the single photovoltaic panel has a low output voltage range,two stage boost inverter topology is often used to meet the demand of grid or AC load supply.The former stage employ DC/DC circuit to boost input voltage,and the latter stage use DC/AC circuit to realize inverter.But this method uses more components,and the two-stage structure is easy to cause the increase of system efficiency loss.The single-stage boost inverter not only simplifies the circuit structure,but also reduces the power level transmission,which can effectively improve the system efficiency.Therefore,this paper proposes a single-stage single-source leakage current free boost photovoltaic inverter after comprehensively describing the structural characteristics of various single-stage boost inverters.The inverter can not only realize the functions of boost and inverter at the same time,but also has the ability of restraining leakage current,which improves the security of the system.In addition,a dual power supply leakage free boost photovoltaic inverter is proposed.The type and voltage level of the proposed inverter topology power can be same or different,which can realize multi energy hybrid utilization and system flexibility.Firstly,the paper introduces the operation principle and steady-state performance of single power DC/AC boost converter topology and dual power DC/AC boost converter topology.At the same time,the voltage gain,voltage and current stress and system loss are calculated.Furthermore,the small signal modeling and analysis of the proposed boost inverter topology are carried out.The fuzzy self-adjusting controller is also designed and compared with the conventional controller.The proposed inverter topology is simulated in Matlab/Simulink,and the results are given.Based on the operation principle,the power switches,diodes,boost inductor and bus capacitance are selected,and the control and sampling circuit of the proposed inverter topology are also designed.The proposed topology use TMS320F2812 DSP as a core.Some main program and it’s flow chart are given.At the last time,theoretical analysis is tested by experiments.