What are the advantages of variable frequency motors compared to conventional motors?

Attentive netizens will find that when we look at some refrigerators, air conditioners or washing machine products, we can see keywords with the word "inverter" in the title. Of course, the frequency conversion mentioned here is the product of variable frequency motor. So what are the characteristics of the inverter motor compared to the motor used in our home appliance products before? What special experience can we bring to us? Let us Explore together.

What are the advantages of variable frequency motors compared to conventional motors? "Frequency conversion" is everywhere

What are the advantages of variable frequency motors compared to traditional motors?

·More energy efficient

All household appliances generate different levels of harmonic voltage and current during motor operation, so that the motor operates under non-sinusoidal voltage and current. Higher harmonics cause an increase in the stator copper loss, rotor copper loss, iron loss and additional losses of the motor, most notably the rotor copper loss. Since the conventional AC asynchronous motor rotates at a synchronous speed close to the fundamental frequency, the high-order harmonic voltage will cause a large rotor loss after cutting the rotor bar with a large slip. In addition, the additional copper consumption due to the skin effect needs to be considered. These losses will cause the motor to generate extra heat, reduce efficiency, and reduce output power. However, if a variable frequency motor is used, its energy consumption can be reduced by 20%-30%.

·long lasting

When the motor is running, the carrier frequency is about several thousand to ten kilohertz, which makes the stator winding of the motor to withstand a high voltage rise rate, which is equivalent to applying a steep shock voltage to the motor to insulate the turn of the motor. Bear a more severe test. The variable frequency motor can work under the voltage of the rectification filter, the performance can be more stable, and the life is longer.

·Low noise

Ordinary asynchronous motors are more complicated in vibration and noise caused by electromagnetic, mechanical, ventilation and other factors. Each time harmonic contained in the variable frequency power supply interferes with the inherent spatial harmonics of the electromagnetic part of the motor to form various electromagnetic exciting forces. When the frequency of the electromagnetic force wave is equal to or close to the natural vibration frequency of the motor body, a resonance phenomenon will occur, thereby increasing noise. Since the operating frequency range of the motor is wide and the range of the rotational speed is large, the frequencies of various electromagnetic force waves are difficult to avoid the natural vibration frequency of each component of the motor. However, variable frequency motors can effectively solve these problems.