Filters - Reactances

Filter for harmonic distortion reducing

The inverters causes some harmonic distortions; the confomity to CEI EN 61000-3-2 (In<=16A, if it is directly connected to low voltage public network) and CEI EN 61000-3-12 (16A<In<=75A, if it is directly connected to low voltage public network) in the final work system should be estimated by the utilizer; Rowan Elettronica provides the following filter types to reduce that distortion.

DV/DT reduction filters for motors

The voltage supplying the motor connected to the inverter is generated by PWM technique, this voltage is therefore formed by a variable lengths of impulses sequence. The high speed of voltage increasing on these dV/dt impulses, can cause high stray currents through the motor power cables, through the actual motor windings and from them to their housings. The high dV/dt also causes, by the intrinsic inductance of the connecting cables, high voltage peaks on the motor windings.
With the aim of reducing all problems caused by dispersion currents and high overvoltages on the windings a range of dV/dt reduction filters has been developed. Their codes and relevant power sizes, in addition to dimensions, are given in the table below.