Study On Quasi-Z Source Bidirectional Full Bridge

Bidirectional converter is a converter that can flow in two directions of energy.With the rapid development of the bidirectional power supply system, the performance of the converter is put forward higher requirements, and the research and development of the bidirectional converter has become a hot topic. In this paper,based on the principle of quasi-Z source full bridge DC-DC converter, according to the demand of two-way energy flowing improved a new DC-DC converter—quasi-Z source bidirectional full bridge DC-DC converter. The bidirectional converter is coupled with the quasi-Z source impedance network and the full bridge sub circuit by both sides of the circuit topology to realize the bidirectional flow of energy.Compared to the traditional bidirectional DC-DC converter, this type of boost ability is more prominent, higher output power quality, meet the two-way demand for power supply systems.In this thesis, the working principle and detailed topological structure of quasi-Z source bidirectional full bridge DC-DC converter, The boost capability and other properties of the Z source impedance network and the quasi-Z source impedance network are discussed and compared. Then a detailed analysis of the quasi Z source bidirectional full bridge DC-DC converter working principle and control strategy, and several control strategies of the MATLAB simulation experiment, so as to have a more comprehensive understanding of the characteristics of its. The further study quasi Z-source bi-directional full bridge DC-DC converter mathematical model, based on the state space average method and the small signal model are established on the basis of the quasi Z-source impedance network and full bridge circuit model, and adetailed analysis of the influence of network impedance variation of main parameters on the dynamic performance of the system.Based on the analysis of the system, the PID and fuzzy controller are designed respectively. Then based on the theoretical basis for the design of the system simulation platform, the correctness and validity of the established through MATLAB / Simulink simulation model of the system and the proposed control scheme, quasi-Z source bi-directional full bridge DC-DC converter capable of under the proposed control strategy and shows good steady-state and transient.