In a power source system, a high-voltage battery and a low voltage battery are configured to store electric powers to be supplied to a traveling motor and an accessory, respectively. A step-up unit is interposed between the low-voltage battery and the traveling motor, and is configured to step up a voltage of the low-voltage battery and apply the stepped-up voltage to the traveling motor. A controller is configured to perform switching to a normal-time electric power supply circuit, in which the high-voltage battery and the traveling motor are coupled to each other, when the high-voltage battery is in a normal state and perform switching to an abnormal-time electric power supply circuit, in which the low-voltage battery and the traveling motor are coupled to each other via the step-up unit, when the high-voltage battery is in an abnormal state.

A torque-speed curve or data of load that is used as a standard to determine an external condition in which an electric vehicle is operating such as incline or no incline, head wind or no headwind, high temperature or low temperature. The system compares samples of actual torque-speed of load data to the standard. Based on the comparison, the system determines the external condition (going up a hill, traveling into a headwind, operating at high temperature) or an abnormal operation of the vehicle powertrain, for example, low tire pressure, elevated friction, wheels out of alignment. Based on the determination, the system takes an action to govern a maximum torque output of the motor to control temperature of the vehicle battery; to raise a wind deflector; to govern maximum speed of the vehicle to reduce danger resulting from low tire pressure, elevated powertrain friction or out of alignment wheels; or to initiate an indication of abnormal conditions.

A torque-speed curve or data of load that is used as a standard to determine an external condition in which an electric vehicle is operating such as incline or no incline, head wind or no headwind, high temperature or low temperature. The system compares samples of actual torque-speed of load data to the standard. Based on the comparison, the system determines the external condition (going up a hill, traveling into a headwind, operating at high temperature) or an abnormal operation of the vehicle powertrain, for example, low tire pressure, elevated friction, wheels out of alignment. Based on the determination, the system takes an action to govern a maximum torque output of the motor to control temperature of the vehicle battery; to raise a wind deflector; to govern maximum speed of the vehicle to reduce danger resulting from low tire pressure, elevated powertrain friction or out of alignment wheels; or to initiate an indication of abnormal conditions.

An electric motor control system of a vehicle includes a temperature module configured to, based on a motor torque request, (i) determine a plurality of stator current values based on a plurality of temperatures and (ii) generate a maximum stator current based on a lowest value of the plurality of stator current values. A torque module configured to, based on the maximum stator current, the motor torque request, and a maximum allowable flux, generate a maximum torque output. A current command module configured to, based on a speed of a rotor of the electric motor and the maximum torque output, generate a d-axis current adjustment and a q-axis current adjustment. A switching control module configured to, based on the d- and q-axis current adjustments, control switching of an inverter module and apply power to stator windings of the electric motor from an energy storage device.

An electric motor control system of a vehicle includes a temperature module configured to, based on a motor torque request, (i) determine a plurality of stator current values based on a plurality of temperatures and (ii) generate a maximum stator current based on a lowest value of the plurality of stator current values. A torque module configured to, based on the maximum stator current, the motor torque request, and a maximum allowable flux, generate a maximum torque output. A current command module configured to, based on a speed of a rotor of the electric motor and the maximum torque output, generate a d-axis current adjustment and a q-axis current adjustment. A switching control module configured to, based on the d- and q-axis current adjustments, control switching of an inverter module and apply power to stator windings of the electric motor from an energy storage device.

An electric motor control system of a vehicle includes a temperature module configured to, based on a motor torque request, (i) determine a plurality of stator current values based on a plurality of temperatures and (ii) generate a maximum stator current based on a lowest value of the plurality of stator current values. A torque module configured to, based on the maximum stator current, the motor torque request, and a maximum allowable flux, generate a maximum torque output. A current command module configured to, based on a speed of a rotor of the electric motor and the maximum torque output, generate a d-axis current adjustment and a q-axis current adjustment. A switching control module configured to, based on the B- and q-axis current adjustments, control switching of an inverter module and apply power to stator windings of the electric motor from an energy storage device.

An electric motor control system of a vehicle includes a temperature module configured to, based on a motor torque request, (i) determine a plurality of stator current values based on a plurality of temperatures and (ii) generate a maximum stator current based on a lowest value of the plurality of stator current values. A torque module configured to, based on the maximum stator current, the motor torque request, and a maximum allowable flux, generate a maximum torque output. A current command module configured to, based on a speed of a rotor of the electric motor and the maximum torque output, generate a d-axis current adjustment and a q-axis current adjustment. A switching control module configured to, based on the B- and q-axis current adjustments, control switching of an inverter module and apply power to stator windings of the electric motor from an energy storage device.

A control device for a transport vehicle configured to travel with a driving force output from an electric motor is provided. When the transport vehicle is driven by a driving force of the electric motor and a variation rate is equal to or less than a predetermined value while a parameter relating to a traveling speed of the transport vehicle is less than a first predetermined value, the control device sets a threshold value, at which an output limit of the electric motor is started based on a parameter relating to a temperature of the electric motor or a temperature of an electric device for driving the electric motor, to a variable value corresponding to a required driving force to the transport.

A control device for a transport vehicle configured to travel with a driving force output from an electric motor is provided. When the transport vehicle is driven by a driving force of the electric motor and a variation rate is equal to or less than a predetermined value while a parameter relating to a traveling speed of the transport vehicle is less than a first predetermined value, the control device sets a threshold value, at which an output limit of the electric motor is started based on a parameter relating to a temperature of the electric motor or a temperature of an electric device for driving the electric motor, to a variable value corresponding to a required driving force to the transport.