摘要 |
The invention relates to converters (inverters, pulse or frequency converters) and to driving magnetically active operating means. According to one embodiment, a circuit arrangement for feeding the operating means 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. |