High-speed motors have low inductance to allow sufficient current to pass through them at their operating frequency. Therefore, they lack the filtering effect of a standard motor, which reshapes the PWM output of the drive to resemble a sinewave. The PWM switching noise passes through the motor windings without mitigation and heats them up. That can lead to overheating and even destruction of the motor windings.

The usual countermeasure is a sine filter between drive and motor. Our standard sine filters are suitable for output frequencies up to 100 Hz. Custom-made filters will be required for higher motor operation frequencies. In some cases, it may suffice to use AC output reactors instead of expensive sine filters. Please clarify such requirements with the motor manufacturer.