Research On Output Series Full-bridge DC Converter Based On Z Source

The use of wind and solar power generation has the advantages of recycling and environmental protection,but these two kinds of energy are generally unstable,therefore,the power generated is generally not directly invested in production and life.The power electronics technology is a technology that supplies power to the load after processing,including boost,inverter,rectification,emergency power supply and other technologies.Z-Source Inverter(ZSI)combines boost and inverter to make up for the traditional voltage source inverter and current source inverter in engineering applications with its own special circuit structure and characteristics.In this paper,a plurality of Z-source full-bridge DC converters are used in combination,and the power-integration system of the series connected in series is built by using the boosting capability of the Z-source inverter and the superposition of the voltage of the series circuit.The system has the advantages of simple structure and easy research.In this paper,the analysis and disturbance equation derivation are made around the working principle and circuit structure of two different power electronic conversion systems with two or more Z-source full-bridge DC converters,which are connected in series or parallel and output in series.Firstly,the transient circuit equivalent transformation and the internal physical quantity relationship are established respectively for the two operating states of the full-bridge DC converter circuit with Z-Source inverter circuit.Then,the state space average method is used to obtain the average state equation in one cycle,and then the disturbance is introduced.The quantity is derived from the dynamic equation,and the mathematical relationship between the control quantity and the output quantity is obtained,and the influence of the internal component parameters on the output stability is analyzed.After discussing the single module,build a modular circuit system,and then analyze the equalization relationship between input power and output power,and obtain the bi-directionality between achieving input power sharing and achieving output power sharing.The relationship between the bidirectionality and the connection mode of the input terminal shows that the input series system can only control the input power equally by the output power sharing.On this basis,the output voltage equalization control strategy and the input series system design input voltage equalization control strategy are designed for the input parallel system.In addition,for the input tandem system,a cross-control strategy is adopted,and the effectiveness of the strategy is verified,and the main factors affecting the power sharing are discussed.Finally,two kinds of circuits are built on the MATLAB/SIMULINK platform,and the simulation is simulated.The final simulation results correspond to the theoretical derivation results.The results show that for the output series system with Z source,not only the high voltage can be stably output,but also the voltage stress of the internal components of a single module can be reduced.