Abstract: A method of diagnosing an open phase fault condition comprising the steps of: determining the q axis motor current in the motor, the motor speed, the q axis motor current demand, and the demanded phase voltage from the controller and outputting a signal indicative of that an open phase fault condition of motor is present when the following conditions are met: (1) the q axis current demand amplitude is above a threshold; (2) the q axis motor current is below a first predefined fraction of the demanded q axis motor current; (3) the demanded phase voltage is greater than a second predefined fraction of the saturated phase voltage value of the motor circuit; and (4) the motor speed is below a threshold speed.

Abstract: An electric motor apparatus having a controller and a torque demand signal modifier. The controller may produce a set signals to a drive stage of the motor where the drive stage applies a voltage to each phase of the motor to cause currents to flow in each phase of the motor corresponding to a current demand signal fed into the controller. The torque demand signal modifier may receive a target torque demand signal representative of a target torque demanded from the motor and outputs an actual torque demand signal which is converted into the current demand signal that is fed to the controller. The actual torque demand increases in value as a function of time towards the target torque demand value following a predefined ramp selected to ensure that the maximum current gradient of the current demand does not exceed a predetermined limit.

Abstract: An apparatus for controlling an electric motor having a controller, a torque demand limit generator, and a drive stage. The controller may be arranged to receive as an input a torque demand signal indicative of the amount of torque demanded from the motor and to produce as an output a set of motor current demand signals. The drive stage may receive the motor current demand signals and is arranged to cause currents to flow in each phase of the motor as required to meet the demanded torque. The torque demand limit generator may be arranged to output a torque demand limit signal indicative of a torque demand limit above which the battery current would exceed one or more limits.

Abstract: A method of diagnosing an open phase fault condition comprising the steps of: determining the q axis motor current in the motor, the motor speed, the q axis motor current demand, and the demanded phase voltage from the controller and outputting a signal indicative of that an open phase fault condition of motor is present when the following conditions are met: (1) the q axis current demand amplitude is above a threshold; (2) the q axis motor current is below a first predefined fraction of the demanded q axis motor current; (3) the demanded phase voltage is greater than a second predefined fraction of the saturated phase voltage value of the motor circuit; and (4) the motor speed is below a threshold speed.

Abstract: An electric motor apparatus having a controller and a torque demand signal modifier. The controller may produce a set signals to a drive stage of the motor where the drive stage applies a voltage to each phase of the motor to cause currents to flow in each phase of the motor corresponding to a current demand signal fed into the controller. The torque demand signal modifier may receive a target torque demand signal representative of a target torque demanded from the motor and outputs an actual torque demand signal which is converted into the current demand signal that is fed to the controller. The actual torque demand increases in value as a function of time towards the target torque demand value following a predefined ramp selected to ensure that the maximum current gradient of the current demand does not exceed a predetermined limit.

Abstract: An apparatus for controlling an electric motor having a controller, a torque demand limit generator, and a drive stage. The controller may be arranged to receive as an input a torque demand signal indicative of the amount of torque demanded from the motor and to produce as an output a set of motor current demand signals. The drive stage may receive the motor current demand signals and is arranged to cause currents to flow in each phase of the motor as required to meet the demanded torque. The torque demand limit generator may be arranged to output a torque demand limit signal indicative of a torque demand limit above which the battery current would exceed one or more limits.