Control device for an AC motor

摘要

A control device for an AC motor, containing an electrically coupled unit (2) for adjusting phase currents, a unit (6) of phase regulators, a memory unit (10), a control unit (13), a three-phase invertor (14) in a bridge circuit, which is connected to a DC voltage source (15) and to an AC motor (1). The present invention also has current sensors (17, 18), for two phases, which are connected to a function converter (16) for harmonics of the phase currents, which function converter (16) is coupled to feedback inputs (19, 20) of the unit (6) of the phase regulator and to a shaping device (22) for a current feedback signal of the third phase. The output of the shaping device (22) for a current feedback signal of the third phase is connected to a feedback input (21) of the unit (6) of phase regulators. The device also contains a unit (11) for analysis of the states of the phase regulators, which unit (11) is coupled to the memory unit (10) and to the unit (6) of phase regulators.