Vehicle Control Unit (VCU) for New Energy Vehicles
Although electric vehicles (EVs) and traditional internal combustion engine vehicles (ICEVs) have completely different powertrain components, they can still be divided into two parts: energy storage unit and drive unit from the perspective of powertrain architecture. EVs use power battery systems instead of fuel tanks to store energy, so a battery management system (BMS) is added. At the same time, EVs use motors instead of internal combustion engines to drive vehicles, so motor controllers (MCUs) replace engine control units (ECUs). So why does EV need to add a vehicle control unit (VCU) more than ICEVs? Therefore, this article mainly discusses the role of VCU in electric vehicles.
The vehicle control unit (VCU), or powertrain controller, is the core control component of new energy vehicles. It must have high reliability and good fault tolerance, electromagnetic compatibility and environmental adaptability to ensure the safe and stable operation of new energy vehicles.
The vehicle control unit can collect accelerator pedal position signals, brake pedal signals and other component signals and make corresponding judgments, control the actions of the control units of the lower components, and then realize the corresponding functions. At the same time, the vehicle controller can also manage and dispatch the vehicle's operating status through the CAN bus.
Composition and Principle
Mainly divided into two schemes: centralized control and distributed control
The basic idea of the centralized control system is that the vehicle controller completes the acquisition of input signals alone, analyzes and processes the data according to the control strategy, and then directly issues control instructions to each actuator to drive the normal driving of the pure electric vehicle.
The advantages of the centralized control system are centralized processing, fast response and low cost; the disadvantages are complex circuits and difficult heat dissipation.
The basic idea of the distributed control system is that the vehicle controller collects some driver signals and communicates with the motor controller and battery management system through the CAN bus. The motor controller and the battery management system transmit the collected vehicle signals to the vehicle controller through the CAN bus. The vehicle controller analyzes and processes the data according to the vehicle information and combined with the control strategy. After receiving the control instructions, the motor controller and the battery management system control the motor operation and battery discharge according to the current status information of the motor and battery.
The advantages of the distributed control system are modularization and low complexity; the disadvantage is relatively high cost.
