The Benefits Of Variable Frequency Motors
The characteristic of the variable frequency motor is that the frequency can be adjusted according to the load to change the speed. Where the voltage is low, the variable frequency motor can reduce the frequency, allowing the motor to start reliably. Where the load is light, the variable frequency motor can be used to reduce the frequency to reduce the speed and current to save energy. Variable frequency motors can also be used in places where the voltage is normal and often at full load, but it is of little significance. It is better to use a cheap ordinary motor.
The frequency conversion motor can meet the required speed requirements by changing the frequency of the motor according to the work needs. Of course, a strong cooling fan is added to ensure the cooling of the motor at low speed.
What are the benefits of using a variable frequency motor?
1. Frequency conversion motor is more energy-saving
All household appliances generate different levels of harmonic voltages and currents during motor operation, so that the motors run under non-sinusoidal voltages and currents. High-order harmonics will cause the increase of stator copper loss, rotor copper loss, iron loss and additional loss of the motor, the most significant is the copper loss of the team. Because the common AC asynchronous motor rotates at a synchronous speed close to the fundamental frequency, the rotor bar will be cut by the high-order harmonic voltage with a large slip, which will cause a large loss of the rotor. In addition to this, additional copper losses due to the skin effect need to be considered. These losses will be suitable for the extra heat of the motor, the efficiency is reduced, and the output power is reduced, but if a variable frequency motor is used, its energy consumption can be reduced by about 20%-30%.
2, the frequency conversion motor harmonic electromagnetic noise and vibration are smaller
The vibration and noise of ordinary asynchronous motors have become more complex due to electromagnetic, mechanical, ventilation and other factors. The time harmonics contained in the variable frequency power supply interfere with the inherent space harmonics of the electromagnetic part of the motor to form various electromagnetic excitation forces. When the frequency of the electromagnetic force wave is consistent with or close to the natural vibration frequency of the motor body, a resonance phenomenon will occur, thereby increasing the noise. Due to the wide operating frequency range of the motor and the wide range of rotational speed variation, it is difficult for the frequencies of various electromagnetic force waves to avoid the natural vibration frequency of each component of the motor. But the frequency conversion motor can effectively solve these problems.
3. The frequency conversion motor can deal with frequent starting and braking
The frequency conversion motor can solve the problems of the efficiency, temperature rise, insulation strength, noise and vibration and cooling of ordinary asynchronous motors, as well as the fatigue and accelerated aging of the mechanical structure and insulation structure caused by frequent starting and braking. instantaneous voltage. The variable frequency motor can be infinitely variable. The infinitely variable speed is from stop to the fastest speed, or from the fastest speed to the stop, there is no gear, it is gradually faster or slower. In addition, the full DC variable frequency motor can divide the motor speed gear into many gears through the inverter to control the motor speed and actual demand, while the maximum number of gears of the AC brush motor is only 3 gears, and the wind speed adjustment cannot achieve the effect of frequency conversion.
4, the inverter motor has a longer service life
When the motor is running, the carrier frequency is about several thousand to ten kilohertz, which makes the stator winding of the motor bear a high voltage rise rate, which is equivalent to applying a steep impulse voltage to the motor, which makes the inter-turn insulation of the motor more severe. The test of the frequency conversion motor can work under the voltage under the rectification filter, the performance can be more stable, and the life is longer.
5. Variable frequency motor can be infinitely variable speed
Stepless speed regulation is from stop to the fastest speed, or from the fastest speed to stop, there is no gear, it is gradually faster or slower, in addition, the full DC variable frequency motor can divide the motor speed gear into many gears through the frequency converter To control the speed and actual demand of the motor, the maximum number of gears of the AC brush motor is only 3 gears, and the wind speed adjustment cannot achieve the effect of frequency conversion.
