A method for operating a motor vehicle comprising at least one first electric machine and at least one second electric machine, which are electrically interconnected to each other, wherein the first electric machine is operated at a first operating point and the second electric machine is operated at a second operating point, wherein the reactive power generated or taken up by the first electric machine at the first operating point is at least partly compensated by the second electric machine operating at the second operating point.

An alternating-current (AC) motor control device that is capable of suppressing current harmonic components flowing through an AC motor and reducing a loss generated in the AC motor can be achieved. The AC motor control device 10 includes a power converter 3 that performs power conversion from direct current (DC) power to AC power, and a control unit 2 that performs synchronous PWM control on the AC motor 1. The control unit 2 includes carrier wave generation units 221, 231, and 232 that generate carrier waves, and PWM pulse generation units 22 and 23 that generate PWM pulses based on the carrier waves and a voltage command value 21A. The carrier wave generation units 221, 231, and 232 each change a cycle of the carrier wave so that harmonic components in d-q orthogonal coordinates of the AC motor 1 are concentrated on a side of either a d axis or a q axis having a larger inductance, the harmonic components being included in the PWM pulse.