Patent ID: 8896275

Claim:
A rotary electric machine for a vehicle comprising: a multi-phase armature winding including a plurality of phase windings that are out of phase with each other; a plurality of pairs of upper-arm and lower-arm switching elements that form a bridge rectification circuit together with the multi-phase armature winding to rectify a voltage induced in the multi-phase armature winding, the plurality of pairs corresponding one-to-one to the plurality of phase windings, each switching element of the plurality of pairs of upper-arm and lower-arm switching elements being electrically connected in parallel with a diode; an on/off-timing setter for each pair of the plurality of pairs of upper-arm and lower-arm switching elements, the on/off timing setter being configured to set, for each switching element of the pair of upper-arm and lower-arm switching elements, on and off timings at which the switching element is to be turned on and off, respectively; a pair of first and second switching element drivers for each pair of the plurality of pairs of upper-arm and lower-arm switching elements, the first switching element driver being configured to turn on and off the upper-arm switching element of the pair of upper-arm and lower-arm switching elements at the on and off timings set by the on/off-timing setter, respectively, and the second switching element driver being configured to turn on and off the lower-arm switching element driver of the pair of upper-arm and lower-arm switching elements at the on and off timings set by the on/off-timing setter, respectively; and a synchronous control start determiner for each pair of the plurality of pairs of upper-arm and lower-arm switching elements, the synchronous control start determiner being configured to determine whether or not an upper-arm on-period and a lower-arm on-period occur in alternating order, and when the upper-arm on-period and the lower-arm on-period occur in alternating order, then determine that it is time to start synchronous rectification in which the pair of upper-arm and lower-arm switching elements are on/off controlled by the on/off-timing setter and the pair of first and second switching element drivers, the upper-arm on-period being an energization period for the upper-arm switching element from when a phase voltage of a corresponding phase winding that is the phase winding corresponding to the pair of upper-arm and lower-arm switching elements reaches a first threshold to when the phase voltage of the corresponding phase winding reaches a second threshold, and the lower-arm on-period being an energization period for the lower-arm switching element from when the phase voltage of the corresponding phase winding reaches a third threshold to when the phase voltage of the corresponding phase winding reaches a fourth threshold.