Electric motor control apparatus

An electric motor control apparatus for a multiphase AC electric motor by comprising:

• a current detecting circuit which detects currents flowing through respective phases of the electric motor;
• current control means for determining a multiphase voltage command in accordance with a torque current command corresponding to a target value of a torque to be generated by the electric motor and detected currents flowing through the respective phases and detected by the current detecting circuit, the current control means including
• normal-state current controlling means for controlling current in a normal state,
• abnormal-state current controlling means for controlling current in an abnormal state,
• abnormal-state determining means for detecting as an abnormal phase an abnormal state of any of a wire of the electric motor, a wire of an inverter, and a wire connecting the electric motor to, the inverter, and
• abnormal phase disconnecting means, wherein
• the abnormal phase disconnecting means disconnects at least one abnormal phase detected by the abnormal-state determining means from the circuit, and
• the abnormal-state current controlling means generates an abnormal-state voltage command corresponding to the abnormal phase detected by the abnormal-state determining means and uses phases, other than a disconnected phase, of the inverter to control currents of the phases, with the abnormal-state voltage command used as the multiphase voltage command;
• and
• a switching element driving circuit which commands the inverter which includes switching elements, through switching manipulation signals, based on the multiphase voltage command from the current control means, to control the switching elements of the inverter, thereby controlling currents fed to the respective phases of the electric motor.