Effect of Voltage Fluctuation on Motor
According to the national standard, the motor power supply voltage can change within +-5% of the rated value, while the motor output power must keep the rated value. The motor power supply voltage should not exceed +-10%the rated value.
If the power supply voltage is too high, the exciting current will increase, and so the motor will overheat, which will endanger the insulation of the motor and make it easy to breakdown.
When the power supply voltage is too low, the electromagnetic torque will be greatly reduced. If the load torque does not reduce accordingly, the increased torque difference between load torque needed and motor able to supply will cause the motor to overload and overheat, which will affect the life of the motor for a long time.
In short, no matter the voltage is too high or too low, the current will increase, and the motor will be damaged by heat.
For the permanent magnet direct drive motor system, its special frequency converter has perfect protection functions such as under-voltage, over-voltage and over-current protection, so as to avoid the influence of the power grid voltage on the life of the motor.