Working Principle and Function Introduction
The controller, as a key power component in electric vehicles, interacts with the vehicle through the CAN network to exchange commands and status information. The controller collects motor current, speed, and position signals, integrates system status and vehicle control commands, and converts the DC power from the vehicle’s high-voltage distribution into AC power to drive the motor.
MCU Main Circuit Schematic
The main circuit of the controller is shown in the figure above. It consists of a DC current sensor Is, voltage acquisition circuit V1 (integrated on the control board), discharge resistor R3, support capacitor C4, motor controller conversion module V1 to V6, AC current sensors ISV and ISW, Y capacitors C2 to C3, X capacitor C1, intermediate resistors R1 to R2, and electrical connection lines and busbars.
Function Descriptions of Various Components and Circuits
Discharge Resistor
After the high-voltage DC power supply is disconnected, the discharge resistor releases the charge on the support capacitor to prevent electric shock. The DC support capacitor stabilizes the DC voltage and provides reactive power to the motor.
DC Current Sensor
Detects the value of the DC current flowing into the controller. The AC current sensor detects the current of the V and W phase lines of the motor.
Introduction to the Working Principle of the Cooling System
1. Water Pump Start/Stop Strategy:
The motor controller starts at 45°C and stops at 38°C; the drive motor starts at 85°C and stops at 70°C.
2. Fan Start/Stop Strategy:
The motor controller starts at 58°C and stops at 46°C; the drive motor starts at 95°C and stops at 85°C.
Fault Codes: 1641: Motor controller (limp mode) reaches reduced power temperature threshold of 75°C 1642: Motor controller (stop mode) reaches reduced power temperature threshold of 80°C 1644: Drive motor (limp mode) reaches reduced power temperature threshold of 135°C 1645: Drive motor (stop mode) reaches reduced power temperature threshold of 165°CTroubleshooting Ideas: 1. Insufficient coolant, wiring harness, connector faults 2. Water pump or fan not working, water pump performance degradation
3. Motor temperature sensor failure
4. Integrated controller failure
5. Residual air or debris blocking the water circulation channel
Working Principle:The motor controller connects to the motor’s resolver windings through a resolver line. First, the motor controller outputs a fixed sine waveform to the excitation winding of the resolver. The change in the motor rotor position affects the amplitude and phase of the cosine and sine groups. The resolver decoding chip decodes the sine and cosine waveforms to calculate the motor angle, position, speed, and other data; real-time monitoring and data transmission.
51: Resolver fault in the motor,
The motor controller detects a significant deviation in the initial positioning angle of the resolver (exceeding 15°)
99: Resolver fault, motor overspeed;
Troubleshooting Ideas: 1. Motor angle deviation; 2. Resolver winding fault; 3. Signal line misconnection; 4. Excitation line misconnection; 5. Motor body fault; 6. Program mismatch with the motorIntroduction to the Motor Temperature Sensor
1679, 1680: Motor sensor fault, motor temperature sensor short circuit or open circuit fault
Troubleshooting: 1. Check if the motor sensor contact line is normal; 2. Check if the motor sensor resistance value is around 120Ω (NTC sensor resistance value should be around 10KΩ) 3. Check the integrated controller end, low-voltage harness X2 connector, for pin retraction
4. Check if the program matches the motor
Control Logic and Pin Definitions
Motor Controller Signal Definitions
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