Research On A Novel Soft-switching Micro Photovoltaic Inverter

In this thesis,small power single-phase photovoltaic inverter is studied,this kind of inverter is mainly suitable for low input voltage systems,such us photovoltaic panels,batteries,fuel cells.Through the comparison of the topologies of single-phase photovoltaic,a micro inverter is proposed,which is consisted of a novel isolated CUK soft-switching DC-DC converter and a voltage source full bridge inverter.Through the theoretical calculation and simulation with Matlab/Simulink,the topological parameters of the system are selected and the working process of the system are completed.Then,corresponding experimental platform is built in the laboratory,and the test results are in agreement with the simulation results.Firstly,the typical structure,main advantages and key technologies of the micro photovoltaic inverter are analyzed.Then,the developments and advantages of the CUK Converter are introduced,so does the evolution of isolated CUK Converter.And then,a novel soft-switching CUK Converter with voltage doubling rectifier function is proposed,and analysis the working process of the circuit in detail.Through the simulation analysis and mathematical calculation,the main topology of the system and the output filter parameters are calculated.Then,the principle analysis and hardware circuit design of DC-DC and DC-AC are carried out respectively.The design ideas of the main circuit,driving circuit,sampling circuit,power supply circuit and others are introduced in this paper.Then,the software design is analyzed,and the modeling,the overall control strategy and the software flow chart are introduced.Finally,the building and debugging of the system experiment platform are finished,The platform is based on TMS320F28335,which is the chip of TI company,in CCS software development environment,we finished the debugging of the experimental platform.The key waveforms of the system are tested and analyzed,and the experimental results and simulation results are compared and analyzed,then the corresponding conclusions are given.