The function of an electric vehicle motor controller: The motor controller is the control unit that operates the motor to drive the entire vehicle, and is a crucial component of an electric vehicle. The motor controller features CAN communication, overcurrent protection, overvoltage protection, undervoltage and overvoltage protection, phase loss protection, energy feedback, power limiting, high-voltage interlock, and fault reporting. Motor controller technology is currently quite mature, possessing characteristics such as high processing speed, high power, long service life, and stable output.
I. Electric Vehicle Motor Controller - Function Introduction
The motor controller features IGBT junction temperature calculation, variable carrier frequency, and overmodulation technology, resulting in high system efficiency, strong power, and high stability. It also includes CAN wake-up and sleep modes to reduce static power loss and prevent battery depletion. The motor controller has regenerative braking; when the vehicle brakes, it stores energy in the battery to improve range. The anti-rollback ramp is designed to prevent the vehicle from rolling backward during incline starts. Upon detecting backward movement, the controller automatically adjusts the torque output to counteract the vehicle's backward movement caused by gravity.
The motor controller also features cruise control. When the accelerator is not pressed, the motor controller automatically outputs torque according to the speed set by the VCU, maintaining the vehicle at a constant speed to save driver effort and improve the driving experience. Idle speed function enables vehicle creeping, effectively outputting torque based on the motor's rated power to keep the motor's rated power within a small speed range. Anti-shake function can be enhanced according to customer requirements to improve overall vehicle vibration reduction and ensure safe and comfortable driving. Active discharge function: after the vehicle stops running and the battery is disconnected from the motor controller, the motor controller should have the function of releasing the charge on the bus capacitor, reducing the phase voltage to a safe level. UDS protocol: UDS is mainly used for vehicle manufacturing and after-sales maintenance. Based on the UDS protocol, diagnostic tools can accurately identify the cause of common faults, improving repair efficiency.
II. Electric Vehicle Motor Controller – Operating Environment
The motor controller operates within a temperature range of -40 to 85℃, and will output power above 65℃. Regarding ambient humidity, the controller can operate normally when the air humidity does not exceed 95%, and it can also operate normally when its surface temperature is below zero and condensation forms on the surface. It can operate normally at altitudes below 3000 meters, and its anti-fouling and waterproof rating is IP67.
III. Electric Vehicle Motor Controller – Common Parameters of Motor Controllers
The motor controller has an input operating voltage of 336V and 540VDC. In addition to voltage, it also has specifications such as rated current, maximum output current, peak operating time, variable load frequency range, maximum efficiency, and maximum output frequency.
IV. Summary
The reliability of the motor controller determines the overall vehicle handling stability, driving force, reliability, and safety factor. Therefore, when selecting and designing the controller model, it is essential to consider factors such as rational installation space, sufficient power, rational current curve, and smooth braking energy feedback.
