Patent ID: 8604730

Claim:
An electric power converter for a three-phase rotary electric machine, which includes two groups of winding wires for each phase of the rotary electric machine, the electric power converter comprising: two inverter units respectively including bridge circuits provided in correspondence to the two groups of winding wires, each bridge circuit including a high voltage side switching element and a low voltage side switching element for each phase of the two groups of winding wires; a capacitor connected to a power supply side and a ground side of each of the two inverter units; and a control unit configured to control ON-OFF switching of the high voltage side switching elements and the low voltage side switching elements by comparing a voltage instruction signal, which indicates voltages respectively applied to the two groups of winding wires, with a predetermined PWM reference signal, wherein the control unit is configured to perform in each of the two inverter units a modulation process that modulates the voltage instruction signal regarding the voltages respectively applied to the two groups of winding wires, the modulation process modulates the voltage instruction signal by controlling an effective voltage vector generation period for each of the two inverter units, as being non-overlapping with each other, where the effective voltage vector generation period is when (a) one phase or two phases of one of the high voltage side switching elements and the low voltage side switching elements are being turned on and (b) the remaining two phases or the remaining one phase of the other one of the high voltage side switching elements and the low voltage side switching elements are being turned off, and wherein the control unit is configured to shift respective phases of the voltage instruction signals regarding the voltages applied to the two groups of winding wires by 30+120×n degrees, where “n” represents an integer number, and wherein the voltage instruction signal for each of the two groups of winding wires attains a maximum value at every interval of 60 degrees.