Abstract: Apparatus for the transfer of electric power produced by at least one multi-phase alternating-current generator (1) or generator unit into at least one multi-phase alternating-current power network (Uu,Uv,Uw), said apparatus comprising at least one control unit (4), at least one non-controlled rectifier bridge (2), a direct-current intermediate circuit and at least one controlled inverter bridge (3) for supplying d.c.

Abstract: A multi-phase voltage-controlled PWM frequency converter, comprising at least one control unit (23), at least one rectifier bridge (20) designed to be connected to a multi-phase supply network (UU, UV, UW), a direct-voltage intermediate circuit and at least one controlled inverter bridge (21) for feeding at least one multi-phase load (22) with an alternating voltage (US, UR, UT) of varying magnitude and frequency. The inverter bridge has pulse width modulation-controlled semiconductor switches (V11-V16) and, in parallel with these, inverse-parallel connected diodes (D11-D16). The rectifier bridge has fully controllable semiconductor switches (V1-V6) and, in parallel with these, inverse-parallel connected diodes (D1-D6).