Patent ID: 8274247

Claim:
A rotary electric machine control system, which switches over a control mode of a rotary electric machine from a sinusoidal wave current control mode to an overmodulation current control mode and from the overmodulation current control mode to a rectangular voltage phase control mode, the rotary electric control system comprising: first current command means for performing a first current command in the sinusoidal wave current control mode or the overmodulation current control mode by using a d-axis current and a q-axis current defined by a maximum efficiency characteristic line formed on a d-q plane defined by a d-axis and a q-axis, which are orthogonal to each other, by connecting each current pair of a d-axis current and a q-axis current, by which the rotary electric machine is driven at a maximum efficiency; second current command means for performing a second current command in the overmodulation current control mode by using the pair of the d-axis current and the q-axis current defined by an early switching characteristic line different from the maximum efficiency characteristic line on the d-q plane until the control mode is switched to the rectangular wave voltage phase control mode, the early switching characteristic line being set at a q-axis side relative to the maximum efficiency characteristic line by connecting current pairs of a d-axis current and a q-axis current; and change means for changing a current command from the first current command to the second current command in a course of switching over the control mode from the sinusoidal wave current control mode to the rectangular wave voltage control mode through the overmodulation current control mode.