The power supply voltage is high, the excitation current is increased, and the motor will distribute heat. Excessive high voltage will insulate the motor and cause it to be broken down. When the power supply voltage is too low, the electromagnetic torque will be greatly reduced. If the load torque is not reduced, the rotor rotation number is too low. At this time, the slip rate is increased, causing the Taicheng motor to be overloaded and heated, which will affect the life of the motor for a long time. .
When the three-phase voltage is asymmetrical, that is, when the voltage of one phase is high or low, it will cause the current of a certain phase to be too large, the motor will heat up, and at the same time, the torque will be "one", and the long time will damage the winding. In short, whether the voltage is too high or too low or the three-phase voltage is asymmetrical will increase the current, and the motor will heat up and damage the motor.
Therefore, according to the national standard, the motor power supply voltage changes within ±5% of the rated value, and the motor output power maintains the rated value. The motor supply voltage must not exceed ±10% of the rated value; the difference between the three-phase supply voltage should not exceed ±5% of the rated value.