Patent ID: 7034412

Claim:
A control apparatus for controlling an electric rotating machine for vehicle comprising: an electric rotating machine having an armature coil and a field coil, being connected to an internal combustion engine for vehicle, and functioning as a starter motor as well as a charging generator; an inverter for supplying an alternating current to said armature coil of said electric rotating machine; field current control means for controlling electric current of said field coil; and control means for controlling operation of said electric rotating machine, when said electric rotating machine functions as a charging generator, in such a manner that power is generated in an inverter generation mode in which a phase-controlled alternating current is applied from said inverter to said armature coil and a generated voltage is subject to step-up chopper control in low-speed rotation range, and that power is generated in an alternator generation mode by controlling the electric current of said field coil in high-speed rotation range; wherein said control means establishes a hysteresis between a first rotating speed of said rotating electric machine at which said rotating electric machine is switched from said inverter generation mode to said alternator generation mode by said control means and a second rotating speed of said rotating electric machine at which said rotating electric machine is switched from said alternator generation mode to said inverter generation mode by said control means.