Variable Frequency Motor

Variable frequency motor refers to the motor that operates continuously at 100% rated load and 10% ~ 100% rated speed under standard environmental conditions, and the temperature rise will not exceed the rated allowable value of the motor.

When the slip rate of induction motor changes little, the speed is directly proportional to the frequency. It can be seen that changing the power frequency can change the speed of induction motor. In frequency conversion speed regulation, it is always hoped that the main flux remains unchanged. If the main magnetic flux is greater than the magnetic flux in normal operation, the magnetic circuit is over saturated, which increases the excitation current and reduces the power factor; If the main magnetic flux is less than the magnetic flux during normal operation, the motor torque decreases.

With the rapid development of power electronic technology and new semiconductor devices, AC speed regulation technology has been continuously improved and improved. The gradually improved frequency converter has been widely used in AC motor with its good output waveform and excellent performance price ratio. For example, AC variable frequency speed regulation motors have been successively used in large motors, medium and small roller table motors, traction motors for railway and urban rail transit, elevator motors, lifting motors for container lifting equipment, motors for water pumps and fans, compressors, motors for household appliances, etc. in steel mills, and good results have been achieved. AC variable frequency speed regulation motor has significant advantages over DC speed regulation motor:

1. Easy speed regulation and energy saving.

2. The AC motor has the advantages of simple structure, small volume, small inertia, low cost, easy maintenance and durability.

3. It can expand the capacity and realize high speed and high voltage operation.

4. Soft start and fast braking can be realized.

5. No spark, explosion-proof, strong environmental adaptability.