More Energy Efficient 

When the motors of all household appliances are running, harmonic voltages and currents of different degrees are generated, which makes 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, the most significant is the rotor copper loss.
Because the ordinary AC asynchronous motor rotates at a synchronous speed close to the fundamental frequency, the high-order harmonic voltage cuts the rotor bar with a large slip, which will cause a large rotor loss.
In addition, the additional copper loss due to the skin effect needs to be considered. These losses will cause the motor to generate additional heat, reduce efficiency, and reduce output power. 
However, the energy consumption can be reduced by about 20%-30% if a variable frequency motor is used.

Long Lifetime

When the motor is running, the carrier frequency is about several thousand to more than ten kilohertz, which makes the stator windings of the motor bear a very high voltage rise rate, which is equivalent to applying a very steep impulse voltage to the motor, so that the inter-turn insulation of the motor bears a more severe test. And the variable frequency motor can work in the rectifier filter under the voltage, which can achieve the much stable performance and longer life.

Low Noise 

The vibration and noise caused by electromagnetic, mechanical, ventilation and other factors of ordinary asynchronous motors become more complicated.

The time harmonics in the frequency conversion power supply interfere with the inherent space harmonics in the electromagnetic part of the motor to form various electromagnetic excitation forces.
When the frequency of electromagnetic force wave is consistent with or close to the natural vibration frequency of the motor body, the resonance phenomenon will occur and the noise will be increased. Due to the wide working frequency range and wide speed variation range of the motor, the frequency of various electromagnetic waves is difficult to avoid the natural vibration frequency of each component of the motor. But variable frequency motor can effectively solve these problems.