Research On Power Distribution Strategy Of Vehicle Dual-stack Fuel Cell System

Fuel cell heavy-duty truck has become the focus of the development of new energy vehicle industry due to its zero pollution,low noise and long endurance.However,at the same time,heavy truck has a large power demand,wide working range,and single stack high-power fuel cell engine has many problems such as frequent starting,high auxiliary consumption and low efficiency.It is very beneficial to improve the efficiency of the power system of the heavy truck and reduce the hydrogen consumption to establish a reasonable power distribution strategy of the dual reactor fuel cell engine by adopting the coordinated control scheme of the dual reactor fuel cell engine.In this paper,the coordinated control strategy of dual-stack fuel cell engine for heavy truck is studiedFirstly,the topology analysis and type selection matching of dual-stack fuel cell are carried out.In view of the connection form,advantages and disadvantages of the components of the dual-stack fuel cell system,the topology of the power system of the heavy-duty truck is selected,and the power battery is defined as the auxiliary power source of the dual-stack fuel cell system.On this basis,the key components are selected and the parameters are calculated.The mathematical model and efficiency analysis of PEMFC system are carried out.The high efficiency power range of fuel cell system is obtained,which is the basis of power distribution strategy.Then,based on the efficiency power curve of the dual stack fuel cell system,the system is divided into different working modes according to the load demand power and the SOC of the power battery.Switch between different modes while driving a heavy truck.In order to improve the efficiency of the system,the working mode of the system is divided according to the load demand power and the SOC of the power battery.The power distribution strategy based on mode switching is proposed to distribute the power inside the dual-stack fuel cell and between the fuel cell and the power cell.According to different power requirements,the working state of the dual-stack fuel cell system is divided into different working modes,and then the working range is set for the fuel cell based on the efficiency curve of the fuel cell.The strategy realizes the reasonable distribution of load power,improves the efficiency of the dual-stack fuel cell system,and reduces the hydrogen consumption of the system.Then,based on the passive control theory,the controller of the dual-stack system is designed,so that the actual output power of the dual-stack system can accurately follow the output reference power of the control strategy in real time.Combining the power allocation strategy with the passive controller,the simulation is carried out according to the transformation of the load demand power to verify the stability of the system output power and the effectiveness of the controller to improve the response speed of the system.Finally,for the dual-stack fuel cell heavy-duty truck,the whole vehicle model is built based on AVL cruise vehicle simulation platform,and the C code generated by the power allocation strategy designed in Simulink is embedded into the whole vehicle model through the DLL interface for joint simulation.The transient cycle condition of C-WTVC heavy commercial vehicle is selected to verify the vehicle dynamic performance and the economy of control strategy.From the simulation results,it can be concluded that the power switching control strategy based on mode switching designed in this paper significantly improves the system efficiency and reduce the hydrogen consumption of the system.The design of the passive controller makes the system improve the response speed and stability on the basis of meeting the power requirements of the drive motor.