When buying and using motors, it is often recommended to buy VFD electric motors. So what is the difference between a VFD electric motor and an ordinary motor?
VFD electric motors are generally divided into constant-torque special motors, special motors with speed measuring devices for feedback vector control, and intermediate-frequency motors. Changing motor rotation on a VFD is one of its functions. In practical applications, we find that there is still a big difference between a VFD electric motor and ordinary motor. For example, the stability and service life of VFD electric motors and ordinary motors are different. VFD electric motors are more power-saving, and VFD electric motors can be used in a wider range.
1. Under the frequency conversion drive, the efficiency of the electrical control equipment will be about 10% higher, and the temperature rise will be about 20% lower, especially in the low frequency area of vector control or direct torque control.
2. VFD electric motors are better than ordinary motors for occasions that require frequent starting, frequent speed adjustment and frequent braking.
3. In terms of electromagnetic noise and vibration, a VFD electric motor has lower noise and smaller electromagnetic vibration than ordinary motor when it is driven by frequency conversion.
4. The insulation strength of the motor. Since the VFD electric motor is specially designed for frequency converter drive, it can withstand a larger du/dt, the insulation strength of VFD electric motor should be high. Especially in the DTC control mode, the insulation strength of the motor is a great test.
5. The main difference is that the VFD electric motor has additional heat dissipation (using independent axial fan forced ventilation). The heat dissipation in low frequency, DC braking and some special applications is much better than that of ordinary AC asynchronous motors.