Automotive motor control is a key technology in electric and hybrid vehicles, which mainly involves precise control of the operating state of the motor to achieve power output, energy recovery and efficient operation of the vehicle. The following is a detailed introduction to automotive motor control:

Control Principle

Vector control: by decomposing the stator current of the motor into torque current and excitation current and controlling them separately, it achieves independent regulation of the torque and flux of the motor, thus improving the control accuracy and dynamic performance of the motor. This control method can make the motor maintain high efficiency and power factor under different working conditions.

Direct torque control: Directly control the torque and magnetic chain of the motor by detecting the stator voltage and current of the motor and calculating the torque and magnetic chain of the motor, and then directly regulate the torque and magnetic chain of the motor by controlling the switching state of the inverter according to the given reference values of the torque and magnetic chain. This control method has fast dynamic response and simple control structure.

Main Functions

Drive control: According to the driver's operating intention, such as the position of the accelerator pedal, gear and other information, the motor is controlled to output the corresponding torque and rotational speed, so as to enable the vehicle to achieve acceleration, deceleration, travelling and parking. By precisely controlling the current and voltage of the motor, it ensures that the motor can provide stable and efficient power output under different working conditions.

Energy Recovery: During braking or deceleration of the vehicle, the motor is switched to power generation mode to convert the kinetic energy of the vehicle into electrical energy and return it to the power battery for storage. By reasonably controlling the intensity and timing of energy recovery, it can improve energy utilisation and increase the vehicle's range.

Protection function: real-time monitoring of the motor's operating status, including current, voltage, temperature and other parameters. When abnormal conditions are detected, such as over-current, over-voltage, overheating, etc., timely protective measures are taken, such as cutting off the power supply, limiting power output, etc., in order to prevent the motor and other equipment from being damaged, and to ensure the safe operation of the vehicle.

Motor controller

Hardware components: usually includes power electronics, microcontroller, drive circuit, sensor interface and communication interface and other parts. The power electronics is responsible for converting the DC power from the power battery to the AC power required by the motor and controlling the current and voltage of the motor; the microcontroller is the core of the motor controller, which executes the control algorithm, processes various input signals and outputs the control commands; the driving circuit is used to amplify the control signals of the microcontroller and drive the switching action of the power electronics; the sensor interface is used for connecting various sensors such as the current sensor, voltage sensor, speed sensor and so on. The sensor interface is used to connect various sensors, such as current sensor, voltage sensor, speed sensor, etc., to obtain the operating parameters of the motor in real time; the communication interface is used to interact with other control units of the vehicle, such as vehicle controller, battery management system and so on.

Software system: The software system of the motor controller mainly includes the control algorithm, fault diagnosis and processing procedures, communication protocols and other parts. The control algorithm is the core of the software, according to different control strategies, such as vector control, direct torque control, etc., to achieve accurate control of the motor; fault diagnosis and processing procedures can monitor the real-time operating status of the motor and the controller, and timely detection and treatment of various faults; communication protocols to ensure that the motor controller and the other control units of the data between the communication is accurate and reliable.

Development trend

Highly integrated: integrating the motor controller with other automotive electronic devices, such as inverters and chargers, to reduce system size and weight, and improve system reliability and efficiency.

High efficiency and energy saving: continuously optimise the control algorithm and power electronics to improve the efficiency of the motor controller and reduce energy consumption to meet the requirements of electric vehicles for range.

Intelligent: Combining artificial intelligence, machine learning and other technologies, the motor control can adapt itself to different driving conditions and environments, and realise more intelligent energy management and driver assistance functions.

Multi-motor cooperative control: With the development of electric vehicle technology, more and more vehicles use multi-motor drive systems, which need to realise the cooperative control between multi-motors to improve the power performance and handling of the vehicle.