How to troubleshoot the drive motor? As the ‘heart’ of a new energy vehicle, the drive motor should follow the logic of ‘from the surface to the inside’ and ‘from simple to complex’, combining the electrical characteristics and mechanical principles to carry out systematic diagnosis. The following is an analysis of the classification of fault phenomena, troubleshooting process, key detection means and typical cases:
Sudden loss of power while the vehicle is travelling, and the instrument displays ‘Drive Motor Failure’ or ‘High Voltage System Disconnection’. High-voltage contactor sticking/false connection motor controller IGBT module breakdown, rotary transformer signal loss (speed feedback error > 2% resulting in controller shutdown).
High-frequency whistling (>80dB), bearing noise, body resonance during motor operation. Failure of rotor dynamic balancing (the amount of imbalance >5g-cm triggers 120Hz vibration), the range is shortened by more than 20%, the maximum speed is reduced under full charge, and the temperature of the motor is abnormally high.
How to troubleshoot the drive motor?Using a portable dynamic balancer, the amount of unevenness should be <1g-cm. Identify the characteristic frequency of bearing failure (BPFO/BPFI) through vibration spectrum analysis. Use Tesla meter to measure the surface magnetic field strength (e.g. N38UH magnet steel remanent magnetism should be >1.2T).
How should drive motor faults be investigated? Through systematic fault tree analysis combined with professional testing equipment, accurate positioning of drive motor faults can be achieved. It is recommended that maintenance personnel master the CAN bus communication protocol, motor control algorithms and other underlying knowledge, and regularly participate in manufacturers’ technical training to cope with the new challenges brought about by the iteration of new energy vehicle technology.
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