Control system and method for controlling electrical power consumption by traction motor caused by wheel slip

1 . A control system for controlling electrical power consumption from energy storage means by a traction motor of a vehicle caused by a wheel slip event, the control system comprising one or more electronic controllers, the one or more electronic controllers configured to:

receive a torque request for the traction motor;

determine a prevailing speed value of the traction motor;

determine a maximum allowable increase in speed of the traction motor to occur during a latency period associated with the prevailing speed value of the traction motor, wherein the maximum allowable increase in speed comprises an increase in speed of the traction motor that is feasible during the latency period without wheel slip or including an acceptable amount of wheel slip;

determine an electrical power consumption limit by:

determining a maximum predicted speed by adding the maximum allowable increase in speed to the prevailing speed value of the traction motor;

accessing a data structure using the torque request and the maximum predicted speed to obtain a predicted power consumption; and

setting the electrical power consumption limit based on the predicted power comsumption; and

control torque provision of the traction motor in dependence on the torque request and the electrical power consumption limit.

2 . The control system of claim 1 , wherein the one or more electronic controllers collectively comprise:

at least one electronic processor having an electrical input for receiving information associated with the torque request for the traction motor of the vehicle, determining the prevailing speed value of the traction motor, determining the maximum allowable increase in speed of the traction motor and determining the electrical power consumption limit; and

at least one electronic memory device electrically coupled to the at least one electronic processor and having instructions stored therein;

and wherein the at least one electronic processor is configured to access the at least one electronic memory device and execute the instructions thereon so as to cause the control system to determine the prevailing speed value of the traction motor, determine the maximum allowable increase in speed of the traction motor, determine the electrical power consumption limit and control torque provision of the traction motor.

3 . The control system of claim 1 , wherein determining the maximum allowable increase in speed of the traction motor comprises determining a prevailing speed of the vehicle and determining the maximum allowable increase in speed of the traction motor in dependence on the prevailing speed of the vehicle.

4 . The control system of claim 3 , wherein determining the maximum allowable increase in speed of the traction motor comprises accessing at least one data structure in dependence on the prevailing speed of the vehicle.

5 . The control system of claim 1 , wherein determining the electrical power consumption limit comprises accessing at least one data structure in dependence on the torque request, the prevailing speed value of the traction motor and the maximum allowable increase in speed of the traction motor.

6 . The control system of claim 5 , wherein the at least one data structure accounts for efficiencies in provision of torque by the traction motor.

7 . The control system of claim 1 , wherein the electrical power consumption limit comprises a limit in terms of electrical current and/or power to be supplied to the traction motor.

8 . The control system of claim 1 , wherein the electrical power consumption limit comprises a limit in terms of electrical current and/or power to be drawn from the energy storage means by the traction motor.

9 . The control system of claim 1 , wherein the latency period of the prevailing speed value of the traction motor is approximately 50 to 100 milliseconds.

10 . The control system of claim 1 , wherein controlling torque provision comprises transmitting the torque request and electrical power consumption limit to control torque provision.

11 . The control system of claim 1 , wherein controlling torque provision comprises determining a speed value of the traction motor having a lower associated latency and determining a torque limit in dependence on a lower latency speed value of the traction motor, the torque request and the electrical power consumption limit.

12 . A vehicle system comprising the control system as claimed in claim 1 , a traction motor and energy storage means.

13 . A vehicle comprising the control system as claimed in claim 1 .

14 . A method for controlling electrical power consumption from energy storage means by a traction motor of a vehicle caused by a wheel slip event, the method comprising:

receiving a torque request for the traction motor of the vehicle;

determining a prevailing speed value of the traction motor;

determining a maximum allowable increase in speed of the traction motor to occur during a latency period associated with the prevailing speed value of the traction motor, wherein the maximum allowable increase in speed comprises an increase in speed of the traction motor that is feasible during the latency period without wheel slip or including an acceptable amount of wheel slip;

determining an electrical power consumption limit by:

determining a maximum predicted speed by adding the maximum allowable increase in speed to the prevailing speed value of the traction motor;

accessing a data structure using the torque request and the maximum predicted speed to obtain a predicted power consumption; and

setting the electrical power consumption limit based on the predicted power consumption; and

controlling torque provision of the traction motor in dependence on the torque request and the electrical power consumption limit.

15 . A non-transitory computer readable medium comprising computer readable instructions that, when executed by a processor, perform the method of one or more of claim 14 .

16 . A vehicle comprising the vehicle system as claimed in claim 12 .