Research On The Integrated Converter And Control Strategy Of Fuel Cell Hybrid Vehicle

In terms of the development direction of new energy vehicles,fuel cell vehicles are new energy vehicles with long range and green emission products.Unlike pure electric vehicles,fuel cell vehicles are generally equipped with two energy sources or even multiple energy sources as the source of driving power.They require independent power converters connected to the high-voltage DC bus or load,which often results in large electrical system size,high cost,low power density and complex control strategies,among other disadvantages.Today,power converters in automotive multi-energy source systems are mainly designed around improved performance characteristics such as integration,high efficiency,high ratio and multiple operating conditions.It is clear that an integrated power converter that enables energy management of multiple energy sources with high efficiency and a wide range of gain outputs is important for the advancement of fuel cell hybrid vehicle technology.Firstly,this paper introduces the research background of fuel cell hybrid vehicles and analyses two hybrid system structures for hybrid vehicles.The research objective is to optimise the converter structure of a parallel two energy source system and to review and compare the current research status of integrated multi-port technology.A non-isolated integrated multiport is chosen as the integration solution for the converter and the integration mechanism of the converter is analysed and illustrated.A new non-isolated two-energy source integrated converter is constructed using parallel combination and multiplexed devices,and the five operating modes of the converter topology are analysed according to the period-inverting pulse timing waveform.Volt-second balance analysis is used to derive the individual gain functions and to calculate the expressions for the power distribution between the two energy sources in the derivation of the principle for the hybrid two-input source operation.The average value of the inductor current is derived and analysed using the law of power conservation.Secondly,to achieve the dynamic responsiveness and stability of the integrated converter,this paper designs an intelligent algorithmic fuzzy controller to be applied to the two energy source system.The state space averaging and small signal modelling methods are used to construct a mathematical model of the two-energy integrated converter system and to obtain a closed-loop PID controller and a fuzzy PID controller.Through comparative analysis,this paper improves the quantization and scaling factors of the fuzzy rules based on Particle Swarm Optimization(PSO)algorithm to obtain a PSO fuzzy PID control method to improve the system dynamic control effect.Then,the hardware framework of the converter system is established,the electronic components of the converter such as inductors and capacitors and power switches and diodes are calculated and selected,the main power circuit,control circuit,sampling circuit and driver circuit are designed,and the system initialization and driver are developed.Finally,the model was built on Matlab/Simulink simulation software for simulation verification;the experimental prototype was built for theoretical verification and analysis of the five operating modes of the converter,and the results showed that the experiments conformed to the theoretical calculations,and the system could achieve power distribution and stable high gain output well,and the energy input current ripple was low,meeting the design requirements.