The Danfoss sine-wave filters are low-pass filters that suppress the switching frequency component from the drive and smooth out the phase-to-phase output voltage of the drive to become sinusoidal. This reduces the motor insulation stress and bearing currents.
By supplying the motor with a sinusoidal voltage waveform, the switching acoustic noise from the motor is also eliminated. At the same time thermal losses in the motor are reduced. Since the motor insulation lifetime is dependent on the motor temperature, the sine-wave filter prolongs the lifetime of the motor.