Functions and Principles of The Main Drive Motor Controller Function of the Main Drive Motor Controller is a device that controls the operating status of the drive motor, and its motor drive system, which is composed of the drive motor, is the heart of the electric vehicle. It obtains the power demand of the whole vehicle from the vehicle controller, obtains the DC power input from the power battery, through the calculation of its own control circuit and the conversion of the converter, outputs the AC current and voltage required to drive the motor, so that the torque and speed of the motor meet the requirements of the whole vehicle. In addition, the kinetic energy of the vehicle can in turn be recovered through the motor system to charge the power battery. The functional block diagram of the main drive motor controller is shown as the following figure.
The main drive motor controller should have the following basic functions in automotive applications:
(1) Status detection function The rotor position, temperature, phase current and other state parameters of the motor are detected by the sensor in real time, and the bus voltage, bus current, temperature and other status parameters of the controller are detected in real time. (2) Communication function Communicates with the vehicle controller, receives the operating instructions it issues, and reports the status of the motor system to it.
(3) Motor control function According to the vehicle instructions and combined with the motor system status, the driving signal of the power semiconductor device is calculated, and the drive motor runs in the desired working state of the vehicle. (4) Diagnostic and protection function According to the real-time monitoring of the motor system status diagnosis of motor system failure, and the implementation of the corresponding fault protection measures. The above functions are only required to control the motor, while the main drive motor controller is also available in automotive applications.
There are basic functions under: (1) has a variety of control modes In automotive applications, the drive motor system mainly works in torque control mode; But also has speed control mode, used for shift speed adjustment, anti-slip slope and other conditions; There is also a fast discharge mode for high-voltage power processes throughout the vehicle. (2) With four quadrant operating capacity The motor controller can control the operation of the drive motor in all four quadrants (forward electric, forward power generation, reverse electric power, reverse power generation four working states) and can be switched quickly, so as to meet the vehicle in the process of forwarding, regression, driving, braking and other different operating needs. In particular, almost all electric vehicles today require a motor controller with energy recovery (running in a power generation state) to increase range. (3) Has perfect software functions In order to meet the general requirements of the automobile controller, the main drive motor controller generally has CAN communication, diagnosis (UDS), boot loader (Bootloader), calibration and other software-related functions. In addition to the basic functions of the above electric vehicle applications, the main drive motor controller may have more functions for different vehicle design requirements, such as high-voltage interlocking function, CAN wake-up function, anti-slip slope function, active damping function, active short circuit function, etc. The main drive motor controller is mainly composed of power circuits and thermal systems (power semiconductor devices such as IGBT or MOSFET, support capacitors, copper rows, thermal systems, etc.), drive and protection circuits (drive chip, gate drive, protection circuit, etc.), control circuits and control software (microcontrollers, peripheral circuits, control software, etc.), and structural components (box, mounts, plug-ins, etc.). Figures 5-32 give an example of the basic composition of the main drive motor controller.
The motor controller was originally connected to the motor, the power battery and the vehicle controller as a stand-alone unit via an external harness. With the increase of system power density, cost and electromagnetic compatibility, motor controllers are increasingly integrated with other related components, as shown in the following Figures. Among them, the motor controller and motor and reducer three-in-one integration, motor controller and DC/DC converter, DC AC inverter and other electronic control integration program is more common, there are a few only motor controller and motor two-in-one integration, such as 48V motor system.
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