When a motor is controlled by a frequency converter, resonance noise will be heard from the motor. This noise, which is the result of the design of the motor,

arises every time an inverter switch in the frequency converter is activated. The frequency of the resonance noise thus corresponds to the switching frequency

of the frequency converter.

and the ripple current ΔI to the motor, which means that current and voltage become

The filter reduces the accel time of the voltage, the peak load voltage U

PEAK

almost sinusoidal. Consequently, the acoustic motor noise is reduced to a minimum.

The ripple current in the Sine-wave Filter coils, will also cause some noise. Solve the problem by integrating the filter in a cabinet or similar.

180

Table of Contents