The Research On Multi-module AC/DC Parallel Converter Based On Phase-shift Full-bridge

With the rapid development of electric power and electron technic and the increasingrequirement of volume, power, reliability to switch source, high frequency, modularity anddigitization have been its main developing direction. The technology of phase-shifting switchshows its advantage in the process of improving and developing. In the meantime, in order torealize the modularity and digitization, ARM controllers are fully made use of. Furthermore,as the capacity of appliances increases, the needs of high-power source module becomesurgent. Since it’s difficult to increase singly the power of single source module, thetechnology of multi-source parallel appeared.This thesis mainly concerns about the PS-FB-ZVS converter.Firstly, this thesis begins with the principle,analyses the working process of thePS-FB-ZVS converter and sums up its advantages and disadvantages. Then this thesis bringforth an improving way: improving it with saturable inductor. On the basis, a detailed analysisof the design and calculation of each parameter of the converter is conducted, includingtransformer voltage ratio, parallel capacity, time of blind spots, saturable inductor andinductance electric capacity of output electric wave etc..Secondly, this thesis introduces the importance and meaning of switch source parallelsystem and deeply discusses various ways of current sharing and confirms the current sharingmeasures of this system. The signal model of PS-FB converter with saturable inductor and thesimulation model based on Matlab/Simulink were established and single module open-loopsimulation and voltage and current double closed-loop simulation were conducted.Based onthe maximum current flow method principle, a two-module parallel system simulation modelwas built and this design which uses the feasibility of current measures was proved.Thirdly, according to system performance indicators, the types of each device in thecircuit were decided and the control circuit of the system was designed and phase shift controlstrategy was achieved with STM32F103ZE processor. The incremental PI digital controlalgorithm software programming was finished and the whole procedural framework of thesystem was given out.Finally, this thesis builds a systematic experiment platform, that is, PS-FB-ZVS-PWMconverter with saturable inductor hardware circuit and a large number of experiments were carried on to prove the rationality and feasibility of the design.