|Sinusoidal output filters for frequency converters are three-phase filters that are installed at the output of the converters, at the output to the motor, as close as possible to the drive in order to eliminate possible problems derived from the generation of pulses.
These filters eliminate the voltage peaks that originate when switching the power modules at high dV/dt. These peaks can reach high voltage values if the connection cables between the drive and the motor are long. The power electronics of the drives generates current and voltage pulses that, when they reach the motor, are converted mainly into three-phase sinusoidal current and voltage with variable frequency. The filters convert the pulse output of the drive into a sinusoidal voltage without any high-frequency pulse. , thus it is possible to increase the distances of the cables from the drive to the motor without the appearance of the dreaded voltage peaks, since these constant voltage values affect the motor causing aging and perforation of winding insulation, pitting and wear of bearings, unnecessary heating and noise, interference emissions through the cables…Sinusoidal filters composed of special inductances and capacitors are low-pass filters that reduce dV/dt by converting the output voltage into a sine wave, thus eliminating all the above mentioned problems.
In these IP00 filters, the capacitors are attached to the inductance.
These filters allow to achieve:
• Reduction of surges.
• dV/dt limitation.
• Reduction of electromagnetic interfaces.