Research on the Power-on and Power-Off Control and Propulsion Control Method in Hybrid and Electric Vehicles 2024-01-2787

The traditional car's power-up and power-down sequence is only designed for 12V low-voltage system, which is harmless to human body and does not involve the functional safety of the vehicle. The existing power-up and power-down technologies for high-voltage systems (above 220V) are mostly designed for pure electric vehicles, plug-in hybrid electric vehicle, and non-plug-in hybrid electric vehicle. There is no one process that is applicable to EV, PHEV, and HEV, and it rarely involves the power-up and power-down sequence of one-key start and remote start, and for the power-down delay problem when there is battery cooling and motor cooling request, the battery failure, DCDC failure, collision, low battery SOC, the active power-down sequence problem when the external charging gun is connected, and the sequence problem when the controller resets the fault. The seven states of the power-up and power-down sequence control defined in this paper are: state 1 is the initial state, state 2 is the CPSR relay disconnection, state 3: the CPSR relay is closed, state 4: the high-voltage relay is closed, state 5: the DCDC is closed, state 6: the initial state of the collision, and state 7: the collision state. Compared with other technologies, the timing definition of the collision state is added. The control logic modeling and simulation analysis of the vehicle's power-up, power-down and motor management system faults are conducted by Simulink, and the verification is carried out under the real vehicle test. The test results show that the power on and the power off treatment accord with the control logic, the failure power off treatment ensures the high voltage safety, and the power on and off control logic is more conducive to the vehicle energy control.