Motor controllers are in full bloom in the hot new energy vehicle market
As the new energy vehicle market will continue to improve in the next few years, the market potential in this field will gradually be released, and the market size of the motor controller will gradually increase. Comprehensive technology and market trend analysis, in the future, the three technological development directions of automotive drive motor systems are permanent magnetization, digitization and integration.
In this article we will continue to analyze another important area of the core components of new energy vehicles - motor controllers.
Battery technology, motor drive and its control technology, energy management technology and electric vehicle technology are the four key technologies of electric vehicles. The electronic control system is used to control components such as batteries and motors. Its functions include: battery management, engine and motor energy management. The electronic control system is composed of a control system such as an ECU, a sensing system such as a sensor, and a driver's intention identification system. The material cost of the electronic control system is not high, but it takes a lot of trials to master the key algorithms. Especially the hybrid vehicle involves the control strategy of oil and electricity mixing, and the technical barriers are high.
As the power conversion unit connecting the battery and the motor in the new energy vehicle, the motor controller is the core of the motor drive and control system. It mainly includes the hardware parts such as the IGBT power semiconductor module and its associated circuit, as well as the software part of the motor control algorithm and logic protection.
The motor drive control system (including the drive motor and motor controller) is the main execution structure in the operation of new energy vehicles. The control and drive characteristics determine the main performance indicators of the vehicle.
Generally speaking, the motor controller is mainly composed of the following parts:
1. The electronic control module (ElectronicController) includes hardware circuits and corresponding control software. The hardware circuit mainly includes the microprocessor and its minimum system, the monitoring circuit for the state of the motor current, voltage, speed, temperature, etc., various hardware protection circuits, and the data interaction with the external control unit such as the vehicle controller and the battery management system. Communication circuit. The control software implements the corresponding control algorithm according to the characteristics of different types of motors.
2. The driver converts the control signal of the microcontroller to the motor to drive the driving signal of the power converter, and isolates the power signal and the control signal.
3. The power converter module (PowerConverter) controls the motor current. Power devices often used in electric vehicles include high-power transistors, gate turn-off thyristors, power FETs, insulated gate bipolar transistors, and smart power modules.
At present, the electric motor controllers of the electric vehicles mostly adopt three-phase full-bridge voltage-type inverter circuit topology, and some products have pre-directional bidirectional DC/DC converters to increase the input AC voltage of the motor end, increase the output power at high speed, and reduce the motor. Design and production costs. In the conventional controller, the DC supporting capacitor is bulky and has poor high temperature resistance. In order to reduce the volume of DC supporting capacitors and even eliminate DC supporting capacitors, the new converter circuit topology and control method have become a new hotspot in electric vehicle application research, but it is still in the stage of practical exploration. At present, the research and development focus of converters for electric vehicles is still concentrated on power electronics integration.
Comprehensive technology and market trend analysis, in the future, the three technological development directions of automotive drive motor systems are permanent magnetization, digitization and integration.
1. Permanent magnetization means that the permanent magnet motor has the advantages of high power density and torque density, high efficiency and easy maintenance. At present, the trend of permanent magnetization of the motor is prominent. According to the consultation data, the permanent magnet synchronous motor has accounted for more than 90% of the use of new energy vehicles in China.
2. Digitization includes digitization of drive control, digitization of drive to CNC system interface, and digitization of measurement unit. The software replaces the hardware to the greatest extent, with other functions such as protection, fault monitoring, and self-diagnosis.
3, integration is mainly reflected in two aspects: 1) motor: motor and engine assembly, motor and gearbox assembly integration; 2) controller: power electronics assembly (power devices, drive, control, Integration of sensors, power supplies, etc.) In the future, the integration of motors, reducers and controllers is a trend that not only reduces the size, but also makes the products more standardized.