Patent ID: 8680796

Claim:
A control device for a power converter to be used by being connected to a polyphase AC generator-motor including an armature winding and a field winding, the polyphase AC generator-motor comprising: a power conversion section; and a control device for controlling ON/OFF of switching elements of the power conversion section, the power conversion section comprising: a bridge circuit including positive-arm switching elements and negative-arm switching elements, for controlling energization of the armature winding; and a field circuit for controlling energization of the field winding by using a field switching element, the control device comprising: a B-terminal voltage detection section for detecting a B-terminal voltage generated between a B-terminal and a reference potential, the B-terminal being an input/output terminal for power of the polyphase AC generator-motor; a field current detection section for detecting a field current flowing through the field winding; a rotation speed calculation section for detecting a rotation speed of the polyphase AC generator-motor; a generated voltage control section for controlling the field current so that the B-terminal voltage of the polyphase AC generator-motor coincides with a generated voltage command; a generated torque control section for controlling, based on the B-terminal voltage and the rotation speed, the field current so that generated torque of the polyphase AC generator-motor coincides with a generated torque command; a control selection section for choosing any one of a control output of the generated voltage control section and a control output of the generated torque control section; and a field current control section for controlling the field current so that the field current coincides with an output of the control selection section, wherein the control selection section comprises a minimum value selection section for choosing and outputting a minimum value between the control output of the generated voltage control section and the control output of the generated torque control section.