Research On Isolated Single-stage Dual Sepic Inverter Topolopy Based On Integrated Magnetics

Single-stage inverter has been widely used in the solar photovoltaic power system.An isolated single-stage dual Sepic inverter is better able to reduce the complexity of thesystem, reduce the cost, improve system reliability and increase power density. The paperpresents an isolated single-stage dual Sepic inverter based on integrated magnetics whichcould boost or buck the voltage. It has two realizable boost and buck output voltageisolated Sepic DC/DC converter topologies which could realize DC/AC single-phaseinverter through the output parallel. For the design of the inverter system, the paper hasresearched on integrated magnetics of inductors and transformers.At first, the paper introduces the basic principles and working conditions of isolatedSepic converter in detail, detailedly analysises the main circuit topology of the proposed,introduces the various working state, and has given the open-loop simulation waveform,and calculates the relevant parameters of the main circuit.The paper also furthers on the reseach of the main circuit topology integratedmagnetics, and presents three integration magnetic strategies, and systematically analyzedrespectively. Through gyrator-capacitance model, the paper simulates the integratedmagnetic system and analyzes the simulation waveform of the inductor current in thecoupling case.Afterwards, for the main circuit structure, the paper uses two control strategies: one isone-cycle nonlinear control strategy, the other is the voltage closd-loop linear controlstrategy. It describes the two working principle of the control system apart, and appliesPsim simulation software got system simulation results.At last, a prototype is produced based on theoretical analysis and simulation results.The paper has completed the hardware design of the main circuit topology, and verify thecorrectness and feasibility of the system by experiment.