EP-4739530-A1 - CONTROL SYSTEM FOR A VEHICLE

EP4739530A1EP 4739530 A1EP4739530 A1EP 4739530A1EP-4739530-A1

Abstract

A vehicle (100) comprises a first propulsion unit (20) comprising an induction motor (22) having a stator (80) and a rotor (90). A control system (50) for the vehicle is configured to operate the induction motor (22) in a first operating mode and in a second operating mode to achieve a first torque value. In the first operating mode, the induction motor (22) is operated with a first stator current and a first rotor current. In the second operating mode, the induction motor (22) is operated with a second stator current and a second rotor current, wherein the second rotor current is less than the first rotor current, and the second stator current is greater than the first stator current. The control system (50) is configured to operate the induction motor (22) in the first operating mode or in the second operating mode in dependence at least in part on a temperature of the rotor (90).

Inventors

GARBO, Francesco
FUCHß, Stefan

Assignees

Jaguar Land Rover Limited

Dates

Publication Date: 20260513
Application Date: 20240705

Claims (15)

1 . A control system for a vehicle, the vehicle comprising a first propulsion unit comprising an induction motor having a stator and a rotor, the control system comprising one or more processors collectively configured to: operate the induction motor in a first operating mode in which, to achieve a first torque value, the induction motor is operated with a first stator current and a first rotor current; and operate the induction motor in a second operating mode in which, to achieve the first torque value, the induction motor is operated with a second stator current and a second rotor current, wherein the second rotor current is less than the first rotor current, the second stator current is greater than the first stator current, wherein the control system is configured to operate the induction motor in the first operating mode or in the second operating mode in dependence at least in part on a temperature of the rotor.
2. The control system of claim 1 wherein the temperature of the rotor is a measured temperature of the rotor or a predicted temperature of the rotor.
3. The control system of claim 1 or 2 configured to determine a required torque for the induction motor and to operate the induction motor in the first operating mode or in the second operating mode in dependence on a magnitude of the required torque.
4. The control system of claim 3 configured to operate the induction motor in the second operating mode when the magnitude of the required torque is above a threshold value of torque.
5. The control system of any one of the preceding claims configured to determine a required torque for the induction motor and to operate the induction motor in the first operating mode or in the second operating mode in dependence on a period of time for which the required torque is continuously needed.
6. The control system of claim 5 configured to operate the induction motor in the second operating mode when the time for which the required torque is needed is above a threshold value of time.
7. The control system of any one of the preceding claims configured to operate the induction motor in the second operating mode in dependence on one or more of: a type of terrain under, or near to, the vehicle; a type of surface under, or near to, the vehicle; a gradient of surface under, or near to, the vehicle; a location of the vehicle; a speed of the vehicle.
8. The control system of claim 7 configured to operate the induction motor in the second operating mode when the type of terrain under, or near to, the vehicle is one or more of: sand; snow; mud.
9. The control system of any one of the preceding claims configured to receive an input selecting a driving mode for the vehicle and to the operate the induction motor in the second operating mode in dependence on the input.
10. The control system of any one of the preceding claims configured to operate the induction motor exclusively in the first operating mode when regenerating electrical energy.
11 . The control system of any one of the preceding claims, wherein the vehicle comprises a second propulsion unit and the control system is configured to: determine an amount of required torque from the first propulsion unit and an amount of required torque from the second propulsion unit; and at least one of: operate the induction motor in the second operating mode when the amount of required torque from the first propulsion unit is above a threshold value of torque; operate the induction motor in the second operating mode when the amount of required torque from the first propulsion unit is more than a percentage of a total of the amount of required torque from the first propulsion unit and the amount of required torque from the second propulsion unit.
12. A propulsion system for a vehicle comprising the first propulsion unit and the control system of any one of the preceding claims.
13. A vehicle comprising the control system of any one of claims 1 to 11 or the propulsion system of claim 12.
14. A method for controlling a vehicle, the vehicle comprising a first propulsion unit comprising an induction motor having a stator and a rotor, the method comprising: operating the induction motor in a first operating mode in which, to achieve a first torque value, the induction motor is operated with a first stator current and a first rotor current; and operating the induction motor in a second operating mode in which, to achieve the first torque value, the induction motor is operated with a second stator current and a second rotor current, wherein the second rotor current is less than the first rotor current, the second stator current is greater than the first stator current, wherein the method operates the induction motor in the first operating mode or in the second operating mode in dependence at least in part on a temperature of the rotor.
15. Computer readable instructions which, when executed by a computer, are arranged to perform the method according to claim 14.

Description

CONTROL SYSTEM FOR A VEHICLE TECHNICAL FIELD The present disclosure relates to a control system for a vehicle. Aspects of the invention relate to a control system for a vehicle, a propulsion system for a vehicle, a vehicle comprising the control system, a method for controlling a vehicle and a non-transitory computer readable medium. BACKGROUND Electric vehicles (EVs) comprise an Electric Drive Unit (EDU) which drives wheels of the vehicle. An EDU may use a permanent magnet (PM) motor or an induction motor (IM). IM-based EDUs have some advantages, but also have some challenges, such as periods of operation with high torque demands. It is an aim of the present invention to address one or more of the disadvantages associated with the prior art. SUMMARY OF THE INVENTION Aspects and embodiments of the invention provide a control system for a vehicle. Aspects of the invention relate to a control system for a vehicle, a propulsion system for a vehicle, a vehicle comprising the control system, a method for controlling a vehicle and a non-transitory computer readable medium as claimed in the appended claims. According to an aspect of the present invention there is provided a control system for a vehicle, the vehicle comprising a first propulsion unit comprising an induction motor having a stator and a rotor, the control system comprising one or more processors collectively configured to: operate the induction motor in a first operating mode in which, to achieve a first torque value, the induction motor is operated with a first stator current and a first rotor current; and operate the induction motor in a second operating mode in which, to achieve the first torque value, the induction motor is operated with a second stator current and a second rotor current, wherein the second rotor current is less than the first rotor current, the second stator current is greater than the first stator current, wherein the control system is configured to operate the induction motor in the first operating mode or in the second operating mode in dependence at least in part on a temperature of the rotor. An advantage of the control system is that the induction motor can meet a torque demand for a longer period of time without overheating. The second operating mode has lower rotor conduction (PR) losses to achieve the same torque value and therefore the induction motor generates less heat in the rotor when it is operated in the second operating mode. The first operating mode is more efficient than the second operating mode. Operating in the first operating mode and in the second operating mode in dependence, at least in part, on a temperature of the rotor has an advantage of conserving battery energy. The control system can operate in the more efficient first operating mode until the temperature of the rotor requires the control system to operate in the less efficient second operating mode. The temperature of the rotor may be a measured temperature of the rotor, such as a temperature measured by a temperature sensor. Alternatively, the temperature of the rotor may be a predicted temperature of the rotor, such as a predicted temperature calculated by a thermal model of the induction motor. An advantage of predicting the temperature of the induction motor, rather than measuring an actual temperature of the induction motor, is that is possible to obtain a temperature for a part of the induction motor which it is not possible to reliably measure with a temperature sensor. The control system may operate the induction motor in the first operating mode or in the second operating mode by comparing the temperature of the rotor with a threshold value. Additionally, or alternatively, the control system may operate the induction motor in the first operating mode or in the second operating mode in dependence on an increase or a decrease in temperature over a period of time (i.e. a positive or negative temperature delta). Optionally, the control system is configured to determine a required torque for the induction motor and to operate the induction motor in the first operating mode or in the second operating mode in dependence on a magnitude of the required torque. Optionally, the control system is configured to operate the induction motor in the second operating mode when the magnitude of the required torque is above a threshold value of torque. Optionally, the control system is configured to determine a required torque for the induction motor and to operate the induction motor in the first operating mode or in the second operating mode in dependence on a period of time for which the required torque is continuously needed. Optionally, the control system is configured to operate the induction motor in the second operating mode when the time for which the required torque is needed is above a threshold value of time. Optionally, the control system is configured to operate the induction motor in the second operating mode in dependence on one or more o