Research On Cooperative Control Of Gas Supply System For Fuel Cell-Lithium Battery Hybrid Vehicle And Its Energy Management

PEM Fuel cell-lithium battery hybrid vehicle is considered as the most promising new vehicle solution due to its high efficiency,low noise,non-pollution and long range.However,the frequent load changes of vehicles lead to short life of PEMFC,which hinders the large-scale promotion of Fuel-Li hybrid vehicle.Control of PEMFC system and research on energy management strategy of hybrid vehicle is effective way to solve this problem.This thesis studies the cooperative control of PEMFC system and the Fuel-Li hybrid vehicle energy management strategy.The main contents are as follows:The Fuel-Li hybrid vehicle model is established.First,a control-oriented model of PEMFC system is developed,which includes stack,ejector,compressor,valve and manifold.Then,the powertrain model of hybrid vehicle,hydrogen consumption model and healthy model are established,which formed the Fuel-Li model together with established PEMFC model.This model can accurately predict vehicle energy consumption,efficiency and life under various load conditions.Cooperative control of PEMFC system based on adaptive super-twisting sliding mode control.At first,an adaptive sliding mode controller based on super-twisting algorithm is designed for three control objectives including oxygen/hydrogen excess ratio and pressure difference between the cathode and the anode.Then,the stability of the designed controller is analysis based on Lyapunov method.Finally,simulation verification is conducted for the proposed algorithm.The simulation results show that the designed controller effectively realizes the cooperative control of cathode side and anode side,which ensures that the system works in the optimal status under the premise that the output meets the power demand.Simultaneously,this algorithm can suppress chattering phenomenon of conventional sliding mode controller,which reduce the loss of actuator and extend life of PEMFC system.Energy management strategy of Fuel-Li hybrid vehicle based on receding horizon optimization.Firstly,a Markov based vehicle power demand prediction method is proposed to realize dynamic vehicle power demand prediction.Then,the optimization problem is proposed by taking the sum of hydrogen consumption and the loss of two battery in the predicted time series as objective function.And the PSO algorithm is used to solve the optimization problem,which obtains future the power output sequence of PEMFC and Li-ion battery under the constraint conditions.Finally,simulations are carried on the MATLAB environment.The simulation results show that the developed energy management strategy can meet the demand power of Fuel-Li vehicle and improve economy and durability significantly.