The invention relates to
converters (inverters, pulse or frequency
converters) and to the driving of “magnetically active” operating means. An effective
switching frequency of the converter is not to be reduced, but nevertheless a reduction in cooling requirements is to be achieved A
noise level produced in the operating means is to be kept low as well. The invention proposes, for this purpose, a circuit arrangement for feeding the operating means (electrically operated
machine (M)) having at least one winding (L1, L2, L3), which circuit arrangement, in at least one first winding phase (S1), comprises a first
branch (Z1) of a frequency converter (WR1) adapted for and operable at a
switching frequency of not higher than 5 kHz for outputting a main
alternating current generated at said
switching frequency and having a substantially lower
operating frequency (f1) to a winding (L1). A second
branch (z1) of another frequency converter (WR2) is adapted for and operable at a second switching frequency of more than 5 kHz for outputting a supplementary
alternating current generated at said switching frequency to the same winding (L1). In the at least one winding (L1), the two alternating currents (iA(t); iB(t)) of the two branches (Z1, z1) are superimposed to form a sum current, namely during parallel operation of the first and second branches (Z1, z1) of the two non-identical inverters.