Control system and method for controlling a thermal management system of an electric vehicle

Abstract

A method for controlling a thermal management system of an electric vehicle includes obtaining, for each operating mode of one or more operating modes of the thermal management system, an energy cost associated with the operating mode; selecting an operating mode based on the one or more obtained energy costs; and providing an output indicating the selected operating mode.

Description

[0001] CONTROL SYSTEM AND METHOD FOR CONTROLLING A THERMAL MANAGEMENT SYSTEM OF AN ELECTRIC VEHICLE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a method and control system for controlling a thermal management system of an electric vehicle. Aspects of the invention relate to a method, to a control system, to computer readable instructions, a computer readable medium, and to a vehicle.

[0004] BACKGROUND

[0005] The temperature of certain components of electric vehicles may have a significant effect on the efficiency of operation of those components. For example, when the temperature is cold, chemical reactions in traction batteries may be inhibited, and in extreme cold the battery electrolyte may freeze, significantly increasing losses in the battery. Conversely, as the temperature of a traction battery increases, resistive losses in the battery may increase. Thus, it may be beneficial to maintain the traction battery of an electric vehicle within a certain range of temperatures Similarly motors, electronics, and other components of the vehicle, along with the vehicle cabin for human comfort, may have desired temperature ranges in which they should ideally be maintained.

[0006] However, managing the temperature of components in the system may draw a significant amount of power from the traction battery, for example when powering a resistive heater, which itself may reduce the efficiency of the use of electrical power provided from the traction battery and therefore reduce the range of the electric vehicle.

[0007] It is an aim of the present invention to address one or more of the disadvantages associated with the prior art.

[0008] SUMMARY OF THE INVENTION

[0009] Aspects and embodiments of the invention provide a method for controlling a thermal management system, and an associated control system, computer readable instructions, computer readable medium, and vehicle, as claimed in the appended claims.

[0010] A disclosed arrangement relates to a control system for controlling a thermal management system of an electric vehicle, the thermal management system having a plurality of operating modes, the control system comprising one or more processors collectively configured to: compare energy costs associated with operating modes of the thermal management system, and select an operating mode from among the operating modes.

[0011] Accordingly, an efficient operating mode may be selected.

[0012] An aspect of the invention provides a control system for controlling a thermal management system of an electric vehicle, the thermal management system having a plurality of operating modes, the control system comprising one or more processors collectively configured to: obtain, for each operating mode of two or more operating modes of the thermal management system, an energy cost associated with the operating mode; select an operating mode based on the obtained energy costs; and provide an output indicating the selected operating mode.

[0013] Accordingly, it is possible to select an operating mode of the thermal management system taking into consideration an energy cost associated with the operating mode. This facilitates energy efficiency, e.g., by allowing an operating mode with a low (or lowest) energy cost to be selected.

[0014] In some examples, the selection of an operating mode comprises selection of an operating mode having a lowest energy cost among the two or more operating modes.

[0015] Accordingly, it is possible to select an operating mode having a low energy cost, improving energy efficiency. The energy cost may indicate one or more of: an energy requirement to transition to the respective operating mode, an energy requirement to operate the thermal management system in the respective operating mode, and heat energy transferred off the vehicle in that operating mode.

[0016] Accordingly, various potential sources of energy cost may be taken into account in the selection of an operating mode.

[0017] In some examples, the one or more processors are collectively configured to: receive thermal energy information fora plurality of components of the electric vehicle, the thermal energy information indicating at least one thermal energy transfer requirement of at least a first component of the plurality of components; and obtain, for each operating mode of the plurality of operating modes of the thermal management system, an indication of compliance of the operating mode with the at least one thermal energy transfer requirement, wherein the selection of an operating mode is based on the obtained energy costs and the indication of compliance of the operating mode with the at least one thermal energy transfer requirement.

[0018] Accordingly, it is possible to select an operating mode of the thermal management system taking into consideration an energy cost associated with the operating mode as well as energy transfer requirements of components of the vehicle. This facilitates energy efficiency, e.g., by allowing an operating mode with a low (or lowest) energy cost to be selected from among operating modes that satisfy the requirements of the components.

[0019] According to disclosed embodiments, a control system for controlling a thermal management system of an electric vehicle is provided, the one or more processors being collectively configured to: receive thermal energy information for a plurality of components of the electric vehicle, the thermal energy information indicating at least one thermal energy transfer requirement of a first component of the plurality of components; obtain, for each operating mode of a plurality of operating modes of the thermal management system, an indication of compliance of the operating mode with the at least one thermal energy transfer requirement; obtain, for one or more operating modes of the thermal management system, an energy cost associated with the operating mode; select an operating mode, wherein the selection is based on the one or more obtained energy costs and the indication of compliance of the operating mode with the at least one thermal energy transfer requirement; and provide an output indicating the selected operating mode.

[0020] Accordingly, it is possible to select an operating mode of the thermal management system taking into consideration an energy cost associated with the operating mode as well as energy transfer requirements of components of the vehicle. This facilitates energy efficiency, e.g., by allowing an operating mode with a low (or lowest) energy cost to be selected from among operating modes that satisfy the requirements of the components.

[0021] In disclosed arrangements, the one or more processors are collectively configured to: receive thermal energy information for a plurality of components of the electric vehicle, the thermal energy information indicating at least one thermal energy transfer requirement of a first component of the plurality of components; assess, for each operating mode of a plurality of operating modes of the thermal management system, an indication of compliance of the operating mode with the at least one thermal energy transfer requirement; obtain, for one or more operating modes of the thermal management system, an energy cost associated with the operating mode; select an operating mode, wherein the selection is based on the one or more obtained energy costs and the indication of compliance of the operating mode with the at least one thermal energy transfer requirement; and provide an output indicating the selected operating mode.

[0022] Accordingly, energy cost associated with the operating mode and energy transfer requirements of components of the vehicle can be taken into account when selecting an operating mode of the thermal management system.

[0023] In disclosed arrangements, there is provided a control system for controlling a thermal management system of an electric vehicle, the one or more processors being collectively configured to: receive thermal energy information for a plurality of components of the electric vehicle, the thermal energy information indicating at least one thermal energy transfer requirement of a first component of the plurality of components; for each operating mode of one or more operating modes of the thermal management system: obtain an energy cost associated with the operating mode, based on the at least one thermal energy transfer requirement; select an operating mode based on the one or more obtained energy costs; and provide an output indicating the selected operating mode.

[0024] Accordingly, an operating mode of the thermal management system can be selected based on an energy cost associated with the operating mode as well as energy transfer requirements of components of the vehicle.

[0025] According to some examples, the selection of an operating mode comprises selection of one or more operating modes from the plurality of operating modes based on the respective indications of compliance

[0026] Accordingly, the energy cost may be determined for operating modes that are determined to comply with the at least one thermal energy transfer requirement.

[0027] In some examples, the one or more processors are collectively configured to obtain, based on the thermal energy information, an indication of one or more components that are requesting thermal energy and one or more components that have excess thermal energy (e.g. are above their target operating temperature ranges and are to be cooled in order to approach their target operating temperature ranges), and determine candidate operating modes, wherein each candidate operating mode is an operating mode of the thermal management system that provides heat to each component that is requesting thermal energy and removes heat from each component that has excess thermal energy, wherein the indication of compliance of an operating mode with the at least one thermal energy transfer requirement is based on whether or not the operating mode is a candidate operating mode.

[0028] Accordingly, an operating mode can be reliably selected that provides appropriate heat transfer (e.g., heating or cooling) to each of the components. In some examples inappropriate operating modes for the current thermal energy transfer requirements can be removed from consideration in simple and reliable manner.

[0029] In some examples the candidate operating modes are determined before the energy costs are obtained, and the candidate operating modes include the two or more operating modes.

[0030] Accordingly, operating modes that are inconsistent with the thermal requirements of the system (e g., in terms of heat flowing to or from components) can be removed from consideration before the energy costs are obtained, reducing the number of modes for which the energy costs are obtained.

[0031] In some examples obtaining an energy cost associated with an operating mode uses more computing resource than determining whether an operating mode is a candidate operating mode.

[0032] Advantageously, determining operating modes before obtaining energy costs may reduce a computation burden associated with selecting an operating mode. For example, compared with determining whether an operating mode is a candidate operating mode, obtaining an energy cost may use more processor time, use more operations, use more memory, or some combination of these.

[0033] In some examples the indication of compliance of an operating mode with the at least one thermal energy transfer requirement is based on the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer in the thermal management system according to the operating mode.

[0034] Accordingly, the selection of the operating mode may take into account whether operating modes are able to satisfy thermal requirements indicated in the received thermal energy information. According to some examples, each operating mode is associated with a respective set of thermal circuits, each thermal circuit comprising a group of the components that are in mutual thermal communication via the thermal management system in the operating mode, the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer in an operating mode comprises the determination, for each thermal circuit in the set of thermal circuits associated with the operating mode, whether an achievable thermal energy transfer in the thermal circuit is consistent with thermal energy transfer requirements of components in the thermal circuit.

[0035] Accordingly, the indication of compliance with the at least one thermal energy transfer requirement can take into account which components are in thermal communication with each other.

[0036] In some examples each operating mode is associated with a respective set of thermal circuits, each thermal circuit comprising a group of the components that are in mutual thermal communication via the thermal management system in the operating mode, wherein the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer in an operating mode comprises, for each thermal circuit in the operating mode: obtain an indication of achievable thermal energy transfer rate in the thermal circuit, obtain an indication of target thermal energy transfer rate in the thermal circuit, and compare the indicated achievable thermal energy transfer rate with the target thermal energy transfer rate.

[0037] Advantageously, the selection of the operating mode may take into account whether operating modes are able to meet a target rate of transfer of thermal energy.

[0038] In some examples each operating mode is associated with a respective set of thermal circuits, each thermal circuit comprising a group of the components that are in mutual thermal communication via the thermal management system in the operating mode, wherein the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer in an operating mode comprises, for each thermal circuit in the operating mode: obtain an indication of thermal energy availability in the thermal circuit, obtain an indication of thermal energy demand in the thermal circuit, and compare the indicated thermal energy availability with the indicated thermal energy demand

[0039] Advantageously, the selection of the operating mode may take into account whether operating modes are able to transfer an amount of thermal energy to satisfy the thermal requirements.

[0040] In some examples, the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer is performed before the energy costs are obtained, wherein operating modes are accepted or rejected based on the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer, and the accepted operating modes include the two or more operating modes.

[0041] Advantageously, the rejection of operating modes on the basis of their achievable thermal energy transfer may be determined before obtaining the associated energy cost As such, the determination of the energy cost associated with rejected operating modes may be avoided.

[0042] In some examples, the energy cost is not obtained for rejected operating modes.

[0043] Accordingly, the determination of the energy cost is not performed for rejected operating modes, reducing at least one of time or computing workload associated with obtaining the energy cost

[0044] In some examples obtaining an energy cost associated with an operating mode uses more computing resource than determining whether an operating mode is accepted or rejected.

[0045] Accordingly, rejecting operating modes before obtaining energy costs may reduce a computation burden associated with selecting an operating mode. The indication of compliance of the operating mode with the at least one thermal energy transfer requirement may indicate whether or not the at least one thermal energy transfer requirement is satisfied in the operating mode.

[0046] Accordingly, an operating mode may be selected based on whether or not the at least one thermal energy transfer requirement is satisfied

[0047] When the operating mode does not satisfy the at least one thermal energy transfer requirement, the indication of compliance of the operating mode with the at least one thermal energy transfer requirement may indicate a degree to which the operating mode does not satisfy the at least one thermal energy transfer requirement.

[0048] Accordingly, it is possible to take into account a degree to which the operating mode does not satisfy the at least one thermal energy transfer requirement. For example, if none of the operating modes can satisfy the at least one thermal energy transfer requirement, an operating mode may be selected based on how close the operating modes come to satisfying the at least one thermal energy transfer requirement.

[0049] In some examples, when the operating mode does not satisfy the at least one thermal energy transfer requirement, the indication of compliance of the operating mode with the at least one thermal energy transfer requirement may indicate a difference between a target thermal energy transfer rate and an achievable thermal energy transfer rate in the operating mode

[0050] Accordingly, it is possible to take into account a difference between a target thermal energy transfer rate and an energy transfer rate that is achievable in a particular operating mode. For example, if none of the operating modes can satisfy the at least one thermal energy transfer requirement, an operating mode may be selected based on how close the operating modes come to satisfying the at least one thermal energy transfer requirement

[0051] In some examples, when the operating mode does not satisfy the at least one thermal energy transfer requirement, the indication of compliance of the operating mode with the at least one thermal energy transfer requirement may indicate a difference between an amount of energy to be transferred according to the at least one thermal energy transfer requirement and an amount of energy transferred in the operating mode.

[0052] Accordingly, it is possible to take into account a difference between a required thermal energy transfer and an energy transfer that is achievable in a particular operating mode. For example, if none of the operating modes can satisfy the at least one thermal energy transfer requirement, an operating mode may be selected based on how close the operating modes come to satisfying the at least one thermal energy transfer requirement

[0053] The electric vehicle may include a set of components having respective target temperature ranges, with the components in the set of components being thermal customers. The thermal management system may be arranged to control temperatures of the thermal customers, e.g. to cause the thermal customers have respective temperatures that are in respective target temperature ranges As such a thermal customer may also be referred to as a controlled component or control target, as the thermal customers may be viewed as components of the electric vehicle that are ultimately controlled by the thermal management system. In some examples, the thermal customers are not components of the thermal management system, but are in thermal communication with the thermal management system.

[0054] The first component may be a first thermal customer, and the at least one thermal energy transfer requirement may include respective thermal energy transfer requirements for a plurality of thermal customers, the plurality of thermal customers including the first thermal customer. The thermal customers my each have a respective target operating temperature range. The thermal management system may be arranged to control temperatures of the thermal customers, e g., to cause the thermal customers have respective temperatures that are in respective target temperature ranges Accordingly, the thermal management system may provide an energy efficient approach to controlling the temperature of thermal customers.

[0055] The thermal customers may include one or more of: a traction battery; an electric drive unit; and a cabin air conditioning unit.

[0056] Accordingly, the thermal management system may manage the temperature of one or more of a traction battery; an electric drive unit; and a cabin air conditioning unit

[0057] In some examples, the plurality of components of the vehicle comprises one or more of: a traction battery; an electric drive unit; a radiator; an outside heat exchanger; a coolant heater; and a cabin

[0058] Accordingly, an operating mode of the thermal management system may be selected based on the at least one thermal energy transfer requirements for thermal customers present on the vehicle, facilitating selection of an operating mode of the thermal management system that retains thermal energy on the vehicle while meeting the thermal requirements of the components.

[0059] According to some examples, the first component has a target operating temperature range, and the at least one thermal energy transfer requirement indicates that the first component is useable as a source of thermal energy and is useable as a sink of thermal energy when the first component is in its target operating temperature range.

[0060] Accordingly, the first component may be used to store surplus thermal energy, rather than transferring it off of the vehicle.

[0061] In some examples the at least one thermal energy transfer requirement for a component includes at least one of: an indication that thermal energy is to be supplied to the component (e.g., the component is requesting thermal energy); an indication that thermal energy is to be extracted from the component (e.g., the component has excess thermal energy); or an indication that thermal energy may be supplied to or extracted from the component (e.g., the component is within a target operating temperature range).

[0062] Accordingly, the selection of the operating mode may take into account the thermal energy status of the components.

[0063] In some examples the at least one thermal energy transfer requirement for a component includes at least one of an indication of a rate of thermal energy to be supplied to or extracted from the component.

[0064] Accordingly, the rate of thermal energy to be supplied to or extracted from the component can be taken into account when selecting the operating mode

[0065] In some examples the at least one thermal energy transfer requirement for a component includes at least one of an indication of an amount of thermal energy to be supplied to or extracted from the component

[0066] Accordingly, the amount of thermal energy to be supplied to or extracted from the component can be taken into account when selecting the operating mode

[0067] In some examples the at least one thermal energy transfer requirement for a component is based on a difference between a current temperature of the component and a target operating temperature associated with the component.

[0068] Accordingly, the selection of the operating mode may be based on whether a component is too hot or too cool.

[0069] The target operating temperature of a component may be a high temperature point or a low temperature point of a target operating temperature range of the component. The target operating temperature may be whichever of the high temperature point or the low temperature point of a target operating temperature range is closest to a current temperature of the component

[0070] Accordingly, the selection of the operating mode may be based on whether a component is within, above, or below a target operating temperature range. In some examples the energy cost of an operating mode comprises a thermal energy cost value representing an amount of thermal energy transferred off the vehicle in that operating mode and an actuator energy cost value representing an energy cost associated with operating the thermal management system in that operating mode.

[0071] Accordingly, an energy cost for each potential operating mode of the thermal management system of the electric vehicle may be evaluated and a mode may be selected based on this (e.g., having a lowest energy cost, such that the most efficient operating mode to meet the required thermal transfer requirements of the components of the vehicle may be selected) In particular (but not exclusively) , the energy cost may include both the cost of operating the thermal management system, for example energy required to operate a compressor, and also a thermal energy cost value representing an amount of thermal energy lost from the vehicle, e g., via a radiator to the environment. Thus, the method is able to select an operating mode for the thermal management system that retains as much thermal energy as possible while meeting the required cooling and / or heating requirements of the components, leading to increased efficiency overall

[0072] In some examples the actuator energy cost value associated with an operating mode is representative of at least one of: an energy cost of operating a compressor according to that operating mode; a valve actuation energy cost associated with that operating mode; a vehicle drag cost associated with operation of a heat exchanger according to that operating mode; an energy cost of operating a pump according to that operating mode; and an energy cost of operating a fan according to that operating mode.

[0073] Accordingly, the method is able to take into account a range of energy costs associated with the operation of the thermal management system, including energy costs associated with transitioning the thermal management system from a first operating mode to a second operating mode, e.g. valve actuation costs.

[0074] According to some examples, each of the plurality of operating modes is associated with a configuration of at least two configurations of the thermal management system, and each configuration defines a direction of flow of thermal transfer fluid to at least one component of the plurality of components.

[0075] Accordingly, the method is operable to select an operating mode for a reconfigurable thermal management system in which the route of a coolant circuit through the components of the vehicle may be changed for different operating modes to facilitate transfer of thermal energy in different directions between components to meet the thermal energy transfer requirements of the components.

[0076] Some examples provide a control system for controlling a thermal management system of an electric vehicle, the control system comprising one or more processors collectively configured to: obtain, for each operating mode of one or more operating modes of the thermal management system, an energy cost associated with the operating mode; select an operating mode based on the obtained energy cost; and provide an output indicating the selected operating mode.

[0077] Some examples provide a control system for controlling a thermal management system of an electric vehicle, the control system comprising one or more processors collectively configured to: receive thermal energy information for a plurality of components of the electric vehicle, the thermal energy information indicating at least one thermal energy transfer requirement of at least a first component of the plurality of components; obtain, for each operating mode of a plurality of operating modes of the thermal management system, an indication of compliance of the operating mode with the at least one thermal energy transfer requirement; obtain, for one or more operating modes of the thermal management system, an energy cost associated with the operating mode; select an operating mode, wherein the selection is based on the one or more obtained energy costs and the indication of compliance of the operating mode with the at least one thermal energy transfer requirement; and provide an output indicating the selected operating mode. Some examples provide a control system for controlling a thermal management system of an electric vehicle, the control system comprising one or more processors collectively configured to carry out any of the methods described herein

[0078] Some examples provide computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform any of the methods described herein.

[0079] Some examples provide a computer readable medium comprising computer readable instructions that, when executed by a processor, cause performance any of the methods described herein.

[0080] The computer readable medium may be a non-transitory computer readable medium.

[0081] Some examples provide a vehicle comprising: any of the control systems described herein; and a thermal management system communicatively coupled to the control system.

[0082] Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner.

[0083] BRIEF DESCRIPTION OF THE DRAWINGS

[0084] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0085] FIG 1 illustrates a thermal management system for an electric vehicle in accordance with an embodiment of the invention;

[0086] FIG 2 illustrates a vehicle including the system of FIG 1 and suitable for implementing embodiments of the invention;

[0087] FIG 3 illustrates a schematic representation of a powertrain thermal management system suitable for implementing embodiments of the invention;

[0088] FIG 4A to FIG 4F illustrate example configurations of the thermal management system in accordance with embodiments of the invention;

[0089] FIG 5 illustrates a method for controlling a thermal management system of an electric vehicle according to embodiments of the invention;

[0090] FIG 6 illustrates an example of a method according to embodiments of the invention; and

[0091] FIG 7 illustrates a control system suitable for performing the methods described herein, according to embodiments of the invention.

[0092] DETAILED DESCRIPTION

[0093] A control system may select an operating mode of a thermal management system to meet thermal energy transfer requirements of components of an electric vehicle, such as a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV). The selection of the operating mode may be based on an energy cost associated with the operating mode (e. g , an operating mode having a lowest energy cost). Thus, according to embodiments, an energy based calculation may be performed for each of a plurality of possible operating modes of the thermal management system to determine the energy cost associated with that operating mode. The energy cost may be determined using predictive thermal models of the thermal management system

[0094] By assessing energy costs associated with respective operating modes, the selection of an operating mode can improve energy efficiency compared to temperature based approaches, for example by avoiding operating modes that have a high energy cost. This may reduce the amount of energy that would otherwise be drawn from the traction battery, resulting in increased range and a corresponding improved user experience.

[0095] Further, by determining an energy cost associated with transitioning to and / or maintaining an operating mode, such as energy to be supplied to actuators, heating elements, compressors, etc. it is possible to select an operating mode that helps to avoid unnecessary energy use.

[0096] By taking a whole system energy based approach for multiple components of the vehicle while taking into account thermal requirements of those components, the amount of thermal energy retained on the vehicle for use by other systems and components may be maximised, or at least substantially increased, compared to temperature based approaches, for example by avoiding rejecting (to an external environment) heat generated in a traction battery during operation that could usefully be transferred to another system such as a climate control system. This increase in retained thermal energy may reduce the amount of energy that would otherwise be drawn from the traction battery to provide heat energy for those other systems, increasing efficiency with which energy is used on the electric vehicle, resulting in increased range and a corresponding improved user experience.

[0097] In some examples, selection of an operating mode may take into account the thermal requirements of the vehicle as well as the energy cost associated with the operating mode. For example, an operating mode may be selected that has a lowest energy cost among operating modes that comply with the thermal energy transfer requirements In another example, where it is determined that no operating mode complies with the thermal energy transfer requirements, an operating mode that is closest to meeting the thermal energy transfer requirements may be selected.

[0098] The selected operating mode can be output as a signal to provide an indication of a selected operating mode of the system to meet the current demands being placed on the thermal management system, and the thermal management system may be controlled according to the output signal to place the thermal management system in the selected operating mode.

[0099] By assessing the energy costs associated with various operating modes, it is possible to avoid selection of modes that are associated with unnecessarily high energy costs, providing improved efficiency. Moreover, by determining compliance of various operating modes with thermal energy transfer requirements, the effectiveness of the thermal management system may be maintained.

[0100] With reference to FIG. 1, there is illustrated a thermal management system 100 for an electric vehicle 200 in accordance with an embodiment of the present invention. The thermal management system includes a controller 106 that is communicatively coupled to a powertrain thermal management system (PTM) 102 and a climate control system 104. The climate control system 104 may comprise a heating, ventilation and air conditioning (HVAC) system. The controller 106 is to receive state information and / or sensor readings from one or more components of the powertrain thermal management system 102 and the climate control system 104, e.g , temperature and mass flow rate values (e.g., based on measurements or models). The mass flow rate may indicate, for example, one or more of a mass flow of a coolant of a cooling circuit, a refrigerant of a refrigerant circuit, or air flow in an air conditioning unit.

[0101] In embodiments, the controller 106 may be communicatively coupled to one or more components of the electric vehicle 200, for example via a controller area network (CAN) bus or similar network present on the electric vehicle 200, and operable to obtain thermal energy information from the components, the thermal energy information defining a thermal energy transfer requirement for each of the components of the electric vehicle 200. The controller 106 is further arranged to provide indications of a selected operating mode to the powertrain thermal management system 102 and a climate control system 104 to influence the operation of those systems. In the arrangement of FIG. 1 , the thermal management system 100 comprises one controller 106, although it will be appreciated that this is merely illustrative. The controller comprises processing means (e.g., processor 108) and memory means (e.g., memory device 110) The processing means may be one or more electronic processing device which operably executes computer-readable instructions 112. The memory means may be one or more memory device. The memory means is electrically coupled to the processing means. The memory means is configured to store instructions 112, and the processing means is configured to access the memory means and execute the instructions 112 stored thereon.

[0102] FIG. 2 illustrates an electric vehicle 200, such as an automobile, provided with a controller 106, powertrain thermal management system 102, and climate control system 104, as shown in FIG. 1. A powertrain of the electric vehicle 200 comprises at least one electric drive unit 202 (e.g., front electric drive unit 202a and rear electric drive unit 202b) and a traction battery 204. The electric drive units 202 comprise one or more electric traction motors for propelling the electric vehicle 200 The traction battery 204 is a high voltage (HV) battery and is configured to supply electrical current to the at least one electric drive unit 202. In the present embodiment, the electric vehicle 200 comprises a front electric drive unit 202a for driving the front wheels of the electric vehicle 200; and a rear electric drive unit 202b for driving the rear wheels of the electric vehicle 200. In use, the front electric drive unit 202a and rear electric drive unit 202b are both powered by the traction battery 204. Each electric drive unit 202 may include power electronics, such as an inverter, to convert DC current sourced from the traction battery 204 to AC current to be supplied to the electric traction motors. As illustrated in FIG. 1 , the powertrain thermal management system 102 is coupled to the climate control system 104 of the cabin of the electric vehicle 200 which is able to control a temperature of the vehicle cabin for occupant comfort.

[0103] While the traction battery 204, electric drive units 202 and climate control system 104 may be the most significant generators and / or users of thermal energy supplied by the powertrain thermal management system 102, it will be recognized that other vehicle components may be coupled to the powertrain thermal management system 102 and may have thermal requirements to be met by the powertrain thermal management system 102. For example, in embodiments, the electric vehicle 200 may further include separate power electronics, such as an on-board AC charger, that may be significant generators of thermal energy while requiring cooling to maintain an operating temperature. Similarly, the electric vehicle 200 may be provided with computer processing hardware that requires active cooling.

[0104] The components of the electric vehicle 200 may have target operating temperature ranges, and operating the components outside of an associated temperature range may lead to increased power consumption by the component or by the electric vehicle 200 as a whole For example, when the temperature of the traction battery 204 increases, internal resistive losses within the traction battery 204 may also be expected to increase, while chemical reactions in the traction battery 204 may be inhibited when cold, similarly leading to increased losses in the battery 204 Such losses may result in reduced range for the electric vehicle 200 when the powertrain components are not maintained within the desired operating temperature range.

[0105] The thermal management system 100 is operable as a source (supply) or sink of thermal energy to components of the vehicle 2OO.The powertrain thermal management system 102 is thermally coupled to the traction battery 204 and electric drive units 202 and is able to extract or supply thermal energy to satisfy thermal energy transfer requirements of these components Similarly, thermal energy may be transferred between the cabin and the climate control system 104. For example, energy may be supplied to the traction battery 204 and electric drive units 202 when beginning operation of the electric vehicle 200 from cold to more quickly bring the components to the desired operating temperature range. During operation of the electric vehicle 200, heat may be generated in the traction battery 204 and electric drive units 202, for example due to internal resistance of the cells of the traction battery 204 To maintain the temperature of the powertrain components within the desired temperature range, heat generated in the powertrain components of the electric vehicle 200 may be extracted by the thermal management system 100 The extracted thermal energy may be transferred between components of the electric vehicle 200 or may be transferred off the electric vehicle 200, for example via a low temperature radiator, to transfer the thermal energy to the outside environment.

[0106] The thermal management system 100 may be operable in a large number of different modes of operation to meet the various thermal transfer requirements of the components. Identifying a most efficient operating mode for the thermal management system 100, based on the current thermal requirements of the vehicle’s components may be difficult and may depend on a range of factors. Some of those factors may be external to the vehicle, such as an ambient temperature.

[0107] A schematic representation of an example powertrain thermal management system 102 is shown in FIG 3 A control valve apparatus 302 is configured to control the circulation of thermal transfer fluid, or coolant, to manage a thermal load of the front electric drive unit 202a, the rear electric drive unit 202b, the battery 204 and the climate control system 104 of the vehicle cabin for occupant comfort. The powertrain thermal management system 102 comprises a coolant heater 304; a first heat exchanger 306; and a second heat exchanger 308. The coolant heater 304 is configured to heat the coolant, for example to provide fast warm-up of traction battery 204 when initially operating the electric vehicle 200 The coolant heater 304 may be a high voltage (HV) heater that draws electrical power directly from traction battery 204.

[0108] The first heat exchanger 306 can be configured selectively to cool the coolant of the powertrain thermal management system 102. A refrigerant circuit of the climate control system 104 is coupled to a refrigerant side of the first heat exchanger 306 to cause the first heat exchanger 306 to operate as a chiller. Thus, the first heat exchanger 306 enables the transfer of heat energy extracted from the coolant to the refrigerant of the climate control system 104 In this way, thermal energy may be transferred from powertrain components for use in heating the cabin of the vehicle, e g. when the powertrain components are above a lower bound of their target operating temperatures. In some embodiments, the first heat exchanger 306 may be bidirectional and allow the transfer of thermal energy from the refrigerant of the climate control system 104 to the coolant of the powertrain thermal management system 102, for example to allow for the supply heat from the outside environment via an outside heat exchanger of the climate control system 104 to heat the coolant. The refrigerant circuit may be coupled to an outside heat exchanger operable to transfer heat between the refrigerant and the outside environment. The supply of refrigerant can be halted to reduce or prevent heat exchange in the first heat exchanger 306. The second heat exchanger 308 is a low temperature heat exchanger (or a low temperature radiator) and is operative to reject heat from the coolant to the outside environment.

[0109] The control valve apparatus 302 comprises a first pump 310 and a second pump 312. The powertrain thermal management system 102 comprises a first coolant circulation loop 314; and a second coolant circulation loop 316. A liquid coolant, or thermal transfer fluid, is circulated through the first coolant circulation loop 314 and second coolant circulation loop 316 to perform supply or sink of thermal energy to the front electric drive unit 202a and rear electric drive unit 202b and the battery 204. At least one coolant temperature sensor 318 may be provided for measuring the temperature of the coolant In the illustrated example, the coolant temperature sensor 318 is provided at an inlet to the second pump 312. The coolant temperature sensor 318 measures the temperature of the coolant supplied to the second pump 312. An electric fan (not shown) may optionally be provided to circulate air over the second heat exchanger 308 to promote cooling of the coolant.

[0110] The first coolant circulation loop 314 is configured to supply coolant to the traction battery 204. The coolant heater 304 and the first heat exchanger 306 are provided in the first coolant circulation loop 314. The coolant heater 304 is provided downstream of the traction battery 204 and, in use, is operative to heat the coolant The first heat exchanger 306 is disposed upstream of the traction battery 204 and, in use, can be configured to cool the coolant prior to introduction into the traction battery 204. As described herein, the first coolant circulation loop 314 and second coolant circulation loop 316 may be selectively connected to each other to enable the supply of coolant from the first heat exchanger 306 to the front electric drive unit 202a and rear electric drive unit 202b.

[0111] The first coolant circulation loop 314 comprises a battery supply conduit 320, and a battery bypass conduit 322. The battery supply conduit 320 is configured to supply coolant to the battery 204. The battery bypass conduit 322 can be selectively opened and closed to control the supply of coolant to perform cooling of the battery 204.

[0112] The second coolant circulation loop 316 is configured to supply coolant to the front electric drive unit 202a and rear electric drive unit 202b. The second heat exchanger 308 is provided in the second coolant circulation loop 316 downstream of the front electric drive unit 202a and rear electric drive unit 202b.

[0113] In use, the second heat exchanger 308 rejects thermal energy from the coolant to the external environment. The second coolant circulation loop 316 comprises a heat exchanger coolant conduit 324 for supplying coolant to the second heat exchanger 308; and a heat exchanger bypass conduit 326 for selectively bypassing the second heat exchanger 308. The control valve apparatus 302 may provide proportional control of the coolant flow rate through the heat exchanger bypass conduit 326, thereby controllably increasing or decreasing the flow through the second heat exchanger 308.

[0114] Control valve apparatus 302 includes crossflow valves 328 that are arranged to couple or decouple the first coolant circulation loop 314 (battery coolant circulation loop) and second coolant circulation loop 316 (electric drive unit coolant circulation loop) In addition, the crossflow valves 328 determine whether the first heat exchanger 306 is coupled in a coolant circulation loop with the battery 204 or the electric drive units 202. In other words, the crossflow valves 328 determine whether the first heat exchanger 306 is coupled in the first coolant circulation loop 314 or the second coolant circulation loop 316, or both when the first 314 and second 316 coolant circulation loops are coupled. The coupling and decoupling of the first coolant circulation loop 314, second coolant circulation loop 316 and first heat exchanger 306, as well as a state (on or off) of the first heat exchanger 306 defines the configuration of the thermal management system 100.

[0115] The first heat exchanger 306, when activated, couples the coolant circulation loop that it is in with the refrigerant circuit. As such, the first heat exchanger 306 is an example of a thermal link component of the powertrain thermal management system 102. A thermal link component is a component that is switchable between a first state, in which the thermal link component provides thermal communication between the cooling system and the refrigerant system, and a second state, in which the thermal link component does not provide thermal communication between the cooling system and the refrigerant system.

[0116] Herein coupling between the first coolant circulation loop 314, second coolant circulation loop 316 and / or the refrigerant circuit indicates that the first coolant circulation loop 314, second coolant circulation loop 316 and / or refrigerant circuit are in thermal communication, such that thermal energy may be transferred between them. Similarly, when they are decoupled, they are not in thermal communication, and no thermal energy (or a negligible amount of thermal energy) is transferred between them.

[0117] The control valve apparatus 302 allows the thermal management system 100 to be controlled to selectively bypass certain components of the powertrain thermal management system 102, such as the second heat exchanger 308, as well as to selectively couple the first coolant circulation loop 314 and second coolant circulation loop 316 together to allow transfer of thermal energy between the components served by the different coolant circulation loops. This means that there may exist a large number of possible arrangements of the thermal management system 100. For each arrangement, one or more components may be controlled to different states, for example the first heat exchanger 306 may be on or off depending on whether refrigerant is provided to the first heat exchanger 306, the second heat exchanger 308 may be selectively bypassed, etc. As such, there may be multiple operating modes of the thermal management system 100 for each of the configurations of the thermal management system 100, resulting in a large total number of possible operating modes for the thermal management system 100 from which an operating mode is to be selected by the controller 106. In embodiments, climate control system 104 includes the refrigerant circuit, the refrigerant circuit including a compressor, at least one internal evaporator operable to extract thermal energy from air in the cabin, at least one internal condenser operable to supply thermal energy to the air in the cabin and an outside heat exchanger for exchanging thermal energy with an outside environment. As discussed above, refrigerant of the climate control system 104 may be selectively provided to first heat exchanger 306 to allow heat energy to be transferred between the coolant of the powertrain thermal management system 102 and the refrigerant of the climate control system 104. Thus, climate control system 104 may be operable in multiple modes. In some embodiments, selection of an operating mode for the climate control system 104 may be coordinated with a selected operating mode for powertrain thermal management system 102 to further improve overall efficiency of the vehicle thermal management system 100.

[0118] The components of the vehicle may include one or more thermal customers. Each thermal customer may have a respective target operating temperature range, or a target operating temperature (for example where the upper and lower limits of the target operating temperature range may be considered to be the same). The thermal management system 100 may be arranged to control temperatures of the thermal customers, e.g., to cause the thermal customers have respective temperatures that are in respective target operating temperature ranges. The traction battery 204; electric drive units 202; and vehicle cabin are examples of thermal customers.

[0119] FIG. 4A to FIG. 4F show examples of configurations of a thermal management system that includes the powertrain thermal management system of FIG 3. Here, the first coolant circulation loop 314 includes the battery 204 and the coolant heater 304, the second coolant circulation loop 316 includes the electric drive units 202 and the second heat exchanger 308 The first coolant circulation loop 314 and second coolant circulation loop 316 may be selectively coupled or decoupled by the crossflow valves 328. Further the first heat exchanger 306 may be coupled with either of the first coolant circulation loop 314 or the second coolant circulation loop 316 (or both when the first coolant circulation loop 314 and the second coolant circulation loop 316 are coupled with each other) by the crossflow valves 328. As shown in FIG 3, the valves 328 in the first and second coolant circulation loops 314, 316 may be arranged in multiple operational positions interconnecting their respective ports 1-4 and 5-8 In FIGS. 4A-4F they have the following arrangements, as will become evident from the description below of the circulation loops resulting when the valves are so arranged:

[0120] FIGS 4A and 4B: as shown in FIG. 3, with ports 1 and 3, 2 and 4, 5 and 7 and 6 and 8 being interconnected;

[0121] FIGS 4C and 4D: different from FIG 3 and 4A, having ports 5 and 8 interconnected and ports 6 and 7 interconnected; and

[0122] FIG. 4E and 4F: as for FIGS. 4C and 4D, except ports 1 and 4 are interconnected, as are ports 2 and 3.

[0123] In FIG 4A the first coolant circulation loop 314 and second coolant circulation loop 316 are decoupled, and the first heat exchanger 306 is in the first coolant circulation loop 314. The first heat exchanger 306 is not active, such that the first coolant circulation loop 314 is decoupled from the CCS 104 that comprises a refrigerant circuit 408. This leads to three thermal circuits being formed The first thermal circuit 402a corresponds with the first coolant circulation loop 314 and includes the battery 204 and coolant heater 304. The second thermal circuit 402b corresponds with the second coolant circulation loop 316 and includes the electric drive units 202 and the second heat exchanger 308. The third thermal circuit 402c corresponds with the refrigerant circuit 408 and includes the internal evaporator 404 and the outside heat exchanger 406.

[0124] FIG. 4B shows the same configuration as FIG. 4A, with the first coolant circulation loop 314 and second coolant circulation loop 316 being decoupled and the first heat exchanger 306 being in the first coolant circulation loop 314. However, in FIG. 4B the first heat exchanger 306 is active, and so the first coolant circulation loop 314 is coupled with the refrigerant circuit 408 This leads to two thermal circuits. A first thermal circuit 402a includes battery 204, coolant heater 304, first heat exchanger 306, internal evaporator 404 and outside heat exchanger 406 The second thermal circuit 402b includes the electric drive units 202 and the second heat exchanger 308.

[0125] In FIG. 4C the first coolant circulation loop 314 and second coolant circulation loop 316 are coupled. The first heat exchanger 306 is also coupled in the first coolant circulation loop 314 and the second coolant circulation loop 316. The first heat exchanger 306 is not active, such that the first coolant circulation loop 314 and second coolant circulation loop 316 are decoupled from the refrigerant circuit 408 This leads to two thermal circuits being formed. The first thermal circuit 402a corresponds with the combined first coolant circulation loop 314 and second coolant circulation loop 316, and includes the battery 204, coolant heater 304, electric drive units 202, and second heat exchanger 308. The second thermal circuit 402b corresponds with refrigerant circuit 408

[0126] FIG. 4D shows the same configuration as FIG. 4C, with the first coolant circulation loop 314 and second coolant circulation loop 316 being coupled However, in FIG. 4D the first heat exchanger 306 is active, and so the first coolant circulation loop 314 and second coolant circulation loop 316 are coupled with the refrigerant circuit 408. This leads to an arrangement with one thermal circuit 402a that includes all of the illustrated components.

[0127] In FIG. 4E the first coolant circulation loop 314 and second coolant circulation loop 316 are decoupled, as in FIG. 4A, but now the first heat exchanger 306 is in the second coolant circulation loop 316. The first heat exchanger 306 is not active, such that the second coolant circulation loop 316 is decoupled from the refrigerant circuit 408. This leads to three thermal circuits being formed. These thermal circuits are the same as in FIG. 4A, except that the first heat exchanger 306 is in the second coolant circulation loop 316. As such, the thermal transfer in this arrangement is the same or similar to the arrangement of FIG. 4A However, these modes of operation are not necessarily equivalent. For example, an energy cost to transition to the mode of FIG. 4A may be less than the energy cost to transition to the mode of FIG. 4E, for example, and so the mode of FIG. 4A may be a better selection than the mode of FIG. 4E in that case. The energy cost of transitioning may be associated with driving actuators to control the crossflow valves 328, for example.

[0128] FIG. 4F shows the same configuration as FIG. 4E, with the first coolant circulation loop 314 and second coolant circulation loop 316 being decoupled and the first heat exchanger 306 being in the second coolant circulation loop 316. However, in FIG 4F the first heat exchanger 306 is active, and so the second coolant circulation loop 316 is coupled with the refrigerant circuit 408. This leads to two thermal circuits. A first thermal circuit 402a includes battery 204 and coolant heater 304. The second thermal circuit 402b includes the electric drive units 202, the second heat exchanger 308, the first heat exchanger 306, the internal evaporator 404, and outside heat exchanger 406

[0129] Arrangements, such as those shown in FIG. 3 and FIG. 4A to FIG. 4F, lead to a significant number of possible operating modes for the thermal management system 100. In each of the configurations, components such as the second heat exchanger 308, coolant heater 304 and outside heat exchanger 406 may each be active or inactive. Similarly, one or more components may be bypassed in the thermal transfer fluid loop, such that bypassed components do not exchange thermal energy via that thermal management system 100. In some examples the number of modes may exceed one hundred. In some examples, the number of modes may exceed two hundred.

[0130] Where a system is capable of fewer configurations, a smaller number of potential operating modes exist and there are fewer options for heat transfer among the components of a vehicle. In such systems, the selection of an operating mode may be straightforward, e.g., using a lookup table that indicates a mode based on temperatures of components of the vehicle (e.g., taking into account the temperatures of three or fewer components) However, the reduced options of transferring heat between components may limit the achievable energy efficiency. In some systems that provide a range of configurations of the thermal management system 100 that are comparable to the examples in FIG. 3 and FIG. 4A to FIG. 4F, the full benefit of these configurations may not be achieved where the system significantly limits selectable combinations of configurations with operation states of components (such as a heater on / off or radiator used / bypassed). In such systems, only a small subset of the potential modes is selectable. Similarly to the case where few configurations are available, in such systems, a mode of the thermal system may be selected based on relative temperatures of the components according to a table of selectable modes. In such systems, the number of selectable modes may be fewer than 20 or fewer than 15, for example. Accordingly, these systems provide limited flexibility in controlling heat transfer between components, potentially losing opportunities for energy efficiency.

[0131] As noted above, in systems having a relatively small number of selectable operating modes (e.g. , 20 or fewer), an operating mode may be selected in a relatively straightforward way, e.g. from a table based on temperatures of the components. The table (or other mode selection method) may be defined in advance based on engineer intuition. Expanding such temperaturebased approaches by considering heat availability or heat demand in specific components in the selection of particular modes does not address the limitations of a system with few selectable operating modes, and does not take efficiency of the operating modes into consideration when selecting an operating mode.

[0132] Where the number of selectable operating modes significantly increases, a selection of a mode based on engineer intuition becomes impractical, and reliably selecting an appropriate operating mode becomes increasingly difficult using a simple tablebased, rules-based, or similar, approach.

[0133] According to examples herein, energy costs associated with different operating modes are determined and used in the selection of an operating mode to be implemented. This may allow for more reliable selection of an energy efficient operating mode Moreover, the selection of the operating mode may better take into account the current state of the components of the vehicle compared with simple temperature-based, table-based, or rules-based approaches.

[0134] FIG. 5 illustrates a method 500 for controlling a thermal management system 100 of an electric vehicle. At block 502 one or more energy costs are obtained, respectively associated with one or more operating modes of the thermal management system 100.

[0135] At block 504 an operating mode is selected based on the one or more obtained energy costs. For example, the operating mode having the lowest energy cost may be selected.

[0136] At block 506 an output is provided indicating the selected operating mode The output may be provided as a signal to components of the thermal management system 100 to provide an indication of a selected operating mode of the system In some examples, the output causes the thermal management system 100 to transition to the selected operating mode.

[0137] The energy cost may indicate one or more of: an energy requirement to transition to the respective operating mode, an energy requirement to operate the thermal management system 100 system in the respective operating mode, and / or heat energy transferred off the vehicle in that operating mode. For example, the energy cost associated with an operating mode may comprise one or more of a thermal energy cost value representing an amount of thermal energy transferred off the vehicle in that operating mode and an actuator energy cost value representing an energy cost associated with operating the thermal management system 100 in that operating mode.

[0138] The actuator energy cost value associated with an operating mode may be representative of at least one of: an energy cost of operating a compressor according to that operating mode; a valve actuation energy cost associated with that operating mode; a vehicle drag cost associated with operation of a heat exchanger according to that operating mode (e.g., vehicle drag associated with active vane management); an energy cost of operating a pump according to that operating mode; and an energy cost of operating a fan according to that operating mode

[0139] The energy cost may, for example, be obtained from a lookup table, or by using a model of the thermal management system 100.

[0140] In some examples, the actuator energy cost may include any energy associated with operating the thermal management system 100, for example an energy cost required to operate the compressor of the refrigerant circuit 408 to provide refrigerant to the first heat exchanger 306, or a drag cost associated with providing airflow to the outside heat exchanger Examples of actuator energy costs associated with an operating mode may include: an energy cost of operating a compressor according to that operating mode; a valve actuation energy cost associated with that operating mode; a vehicle drag cost associated with operation of a heat exchanger according to that operating mode; an energy cost of operating a pump according to that operating mode; and an energy cost of operating a fan according to that operating mode. Certain actuators in the thermal management system 100, for example pumps, compressors, fans, etc., may have an associated duty cycle or activation level setting to satisfy the thermal energy transfer requirements of the components when the thermal management system 100 is operating in a particular operating mode. Energy costs for actuators may be further calculated based on the duty cycle to provide a more accurate determination of the energy associated with operating the actuator.

[0141] The energy cost for each operating mode may be determined using a predictive model of the thermal management system 100. In embodiments, the predictive model of the thermal management system 100 may comprise a plurality of predictive models each associated with a respective sub-component of the thermal management system 100. Thus, each actuator energy cost may be calculated using a model of the respective actuator that defines a relationship between one or more operating parameters of the thermal management system 100 and an energy cost associated with the actuator. For example, a predictive model for the compressor of the refrigerant circuit 408 may allow an energy cost of operating the compressor to be determined based on certain operating parameters, such as the duty cycle Each model may be determined empirically or through simulation of the thermal management system 100 and climate control system 104. In some embodiments, a model for each actuator may be stored as a look up table (LUT) associating one or more operating parameters of the actuator with an associated actuator energy cost.

[0142] Similarly, predictive models may be provided for the first and second heat exchangers and for an outer heat exchanger of the refrigerant circuit 408 to allow the thermal energy to be transferred off the vehicle to the outside environment to be determined based on one or more measured parameters. For example, heat rejected to the outside environment by the second heat exchanger 308 may be predicted based on one or more of: an ambient temperature of the outside environment; a flow rate and / or temperature of coolant through the second heat exchanger 308; an operating state of a fan associated with the second heat exchanger 308, etc.

[0143] In embodiments, the actuator energy cost for an operating mode may be determined by summing all of the actuator energy costs associated with operating the thermal management system 100 in that operating mode to meet the thermal transfer requirements of the components. The energy cost associated with the operating mode may then be calculated by summing the actuator energy cost with the total amount of thermal energy transferred off the vehicle via the second heat exchanger 208 and the outside heat exchanger of the refrigerant circuit 408.

[0144] In some examples, compliance of an operating mode with one or more thermal energy transfer requirements may be a factor in the selection of the operating mode. Thermal energy information may be received for a plurality of components of the electric vehicle, the thermal energy information indicating at least one thermal energy transfer requirement of at least a first component of the plurality of components. In some examples the thermal energy information may also describe thermal transfer capabilities of components.

[0145] The first component is a component having a target operating temperature range, and may be a thermal customer. A component having a single target temperature may be considered to have a target operating temperature range of width zero, such that the upper and lower limits of the temperature range are the same.

[0146] The method may include obtaining, for each operating mode of a plurality of operating modes of the thermal management system 100, an indication of compliance of the operating mode with the at least one thermal energy transfer requirement Further, the selection of an operating mode may be based on the one or more obtained energy costs and the indication of compliance of the operating mode with the at least one thermal energy transfer requirement.

[0147] Obtaining an indication of compliance of the operating mode with the at least one thermal energy transfer requirement may include assessing compliance of the operating mode with the at least one thermal energy transfer requirement and providing the indication of compliance.

[0148] The thermal energy information may include a plurality of thermal energy transfer requirements, for example associated with respective thermal customers.

[0149] FIG. 6 shows an example of a method according to some examples. Thermal energy information is received at block 602, and at block 604 an indication of compliance of an operating mode under consideration with the thermal energy transfer requirement(s) is received. At block 606 the compliance of the operating mode with the thermal energy transfer requirement(s) is checked and, if the operating mode is indicated as complying with the thermal energy transfer requirement(s) the method proceeds to block 608, where the energy cost associated with the operating mode is determined, as described previously, and the method proceeds to block 610. Alternatively, if the operating mode does not comply with the thermal energy transfer requirements) the method proceeds from block 606 to block 610. At block 610 it is determined whether there are any more operating modes to consider. If there are no more operating modes to considers, the method stops at block 614. On the other hand, if there are more operating modes to consider, the method proceeds from block 610 to block 612. At block 612 the information on the next operating mode is obtained, and the method returns to block 604, with the new operating mode (received at block 612) being the operating mode under consideration.

[0150] An operating mode may be selected at block 614, based on the energy costs associated with operating modes that comply with the thermal energy transfer requirement(s). Note that in the arrangement of FIG 6, energy costs are only obtained for operating modes that comply with the thermal energy transfer requirement(s), and so the selection is also based on the compliance of the operating modes with the thermal energy transfer requirement(s). Put another way, in the arrangement of FIG. 6, the selecting an operating mode includes selecting, based on the indication(s) of compliance, the one or more operating modes for which an energy cost is to be obtained.

[0151] Where there is more than one thermal energy transfer requirement an operating mode may be considered to comply with the thermal energy transfer requirements if the operating modes complies with all of the thermal energy transfer requirements.

[0152] According to the arrangement of FIG. 6, the energy cost need not be obtained for operating modes that do not comply with the at least one thermal energy transfer requirements. This may lead to improved computational efficiency, particularly where obtaining the energy cost uses more computing resource than obtaining an indication of compliance with the thermal energy transfer requirements.

[0153] Where a large number of operating modes are considered, obtaining energy costs for every operating mode may be computationally prohibitive, and this may be ameliorated by removing non-compliant operating modes from consideration without obtaining associated energy costs. Computational efficiency may be important where computational resources are limited, such as in some on-board controllers in vehicles. In addition, in some implementations, interfaces with other elements of the vehicle control system may place strict time constraints on the selection of the operating mode, and for this reason also, computational efficiency may be important when implementing the selection of the operating mode.

[0154] In some examples, the indication of compliance of an operating mode may be based on a determination of whether the operating mode provides a flow of thermal energy to each component that has a thermal energy deficit, and the operating mode provides a flow of thermal energy away from each component that has excess thermal energy. Put another way, the indication of compliance may be based on determining whether the operating mode heats all thermal customers that are too cool (i.e have a temperature below their target operating temperature range) and cools all thermal customers that are too hot (i e. have a temperature above their target operating temperature range).

[0155] Accordingly, it can be readily determined whether the direction of flow of thermal energy in the operating mode corresponds with the demand in the system. This determination can generally be performed with relatively few computational resources, and in such cases, selection of modes for further consideration (e.g., by determining respective energy costs) may reduce a computational burden associated with the method.

[0156] In some examples, the method includes obtaining, based on the thermal energy information, an indication of one or more components that are requesting thermal energy (e.g , that have a thermal energy deficit) and one or more components that have excess thermal energy. Components that are requesting thermal energy may correspond with thermal customers that have a temperature below their target operating temperature range Components that have excess thermal energy may correspond with thermal customers that have a temperature above their target operating temperature range. Some components or thermal customers may be indicated as requesting no thermal energy transfer (e.g., if they are at their target operating temperature or in their target operating temperature range). In some examples, if a thermal customer is within its target operating temperature range and can increase or decrease its temperature (i.e., receive or provide thermal energy) while remaining within its target operating temperature range, the thermal customer may be indicated as available to act as a source or a sink for thermal energy. As such, in some examples, the first component may have a relatively broad target operating temperature range, and the thermal energy transfer requirement may operate the first component as a source or a sink of thermal energy while the first component remains in its target operating temperature range.

[0157] In some examples the thermal energy transfer requirement for a component, such as the first component, includes at least one of: an indication that thermal energy is to be supplied to the component (e.g. the component is requesting thermal energy, this may correspond with the component being below its target operating temperature range); an indication that thermal energy is to be extracted from the component (e.g. the component has excess thermal energy, this may correspond with the component being above its target operating temperature range); or an indication that thermal energy may be supplied to or extracted from the component (e.g the component is within a target operating temperature range, in particular where the component has capacity to receive or provide thermal energy and remain in its target operating temperature range).

[0158] The method may further include determining candidate operating modes, wherein each candidate operating mode is an operating mode of the thermal management system that provides heat to each component that is requesting thermal energy and removes heat from each component that has excess thermal energy, “excess” here indicating that the component is above its target operating temperature range.

[0159] The indication of compliance of an operating mode with the at least one thermal energy transfer requirement is based on whether or not the operating mode is a candidate operating mode For example, if it is determined that an operating mode is not a candidate operating mode, the indication of compliance may indicate that the operating mode is not compliant with the thermal energy transfer requirements.

[0160] In some examples, the candidate operating modes are determined before the energy costs are obtained, and the candidate operating modes include the one or more operating modes for which energy costs are to be determined. Accordingly, energy costs may be obtained only for operating modes that are candidate operating modes, which may improve computational efficiency, particularly where obtaining an energy cost associated with an operating mode uses more computing resource than determining whether an operating mode is a candidate operating mode.

[0161] In some examples, the indication of compliance of an operating mode with the thermal energy transfer requirement is based on comparing the thermal energy transfer requirement with an achievable thermal energy transfer in the thermal management system according to the operating mode.

[0162] In some examples, comparing the thermal energy transfer requirement with an achievable thermal energy transfer may include assessing thermal energy transfer requirement and achievable thermal energy transfer separately for each thermal circuit of the operating mode.

[0163] As described in relation to FIG. 4A to FIG. 4F, each operating mode may be associated with a respective set of thermal circuits, each thermal circuit comprising a group of the components that are in mutual thermal communication via the thermal management system in the operating mode. Comparing the thermal energy transfer requirement with an achievable thermal energy transfer in an operating mode may include determining, for each thermal circuit in the set of thermal circuits associated with the operating mode, whether an achievable thermal energy transfer in the thermal circuit is consistent with thermal energy transfer requirements of components in the thermal circuit. For example, in the mode illustrated in FIG. 4A the achievable thermal energy transfer in the first thermal circuit 402a is compared with the thermal energy transfer requirements associated with the first thermal circuit 402a, the achievable thermal energy transfer in the second thermal circuit 402b is compared with the thermal energy transfer requirements associated with the second thermal circuit 402b, and the achievable thermal energy transfer in the third thermal circuit 402c is compared with the thermal energy transfer requirements associated with the third thermal circuit 402c In some examples, the operating mode may be determined to comply with the thermal energy transfer requirement if it is determined that the achievable thermal energy transfer in each thermal circuit of the operating mode is consistent with the thermal energy transfer requirements in each respective thermal circuit. In some examples, the operating mode may be determined not to comply with the thermal energy transfer requirement if it is determined that, for any thermal circuit of the operating mode the achievable thermal energy transfer in that thermal circuit of the operating mode is not consistent with the thermal energy transfer requirements in that thermal circuit.

[0164] The thermal energy transfer requirements may include one or more of an amount of thermal energy transfer requested by the first component, and a rate of transfer of thermal energy requested by the first component. Accordingly, the thermal energy transfer requirement for a component may include at least one of: an indication of a rate of thermal energy to be supplied to the component, a rate of thermal energy to be extracted from the component, an indication of an amount of thermal energy to be supplied to the component, or an indication of an amount of thermal energy to be extracted from the component.

[0165] Where the thermal energy transfer requirements indicate target rates for thermal energy transfers, a thermal energy transfer requirement may indicate a target rate of heating or cooling of a thermal customer in order for the operating mode to be considered satisfactory. Accordingly, comparing the thermal energy transfer requirement with an achievable thermal energy transfer in an operating mode may comprise, for each thermal circuit in the operating mode: obtaining an indication of achievable thermal energy transfer rate in the thermal circuit, obtaining an indication of target thermal energy transfer rate in the thermal circuit, and comparing the indicated achievable thermal energy transfer rate with the target thermal energy transfer rate In some examples the target thermal energy transfer rate of a thermal customer may be determined based on a temperature of the thermal customer and a target operating temperature range of the thermal customer In some examples the target thermal energy transfer rate may be based on a model of the component. In some examples, the target thermal energy transfer rate may be obtained from a lookup table. In some examples, the thermal energy transfer requirement for a component may be based on a difference between a current temperature of the component and a target operating temperature or target operating temperature range associated with the component.

[0166] Where a component has a target operating temperature range, the target operating temperature of the component may be a high temperature point or a low temperature point of a target operating temperature range of the component. The target operating temperature may be whichever of the high temperature point or the low temperature point of a target operating temperature range is closest to a current temperature of the component, assuming the current temperature of the component is presently outside the target range.

[0167] Where the thermal energy transfer requirements indicate amounts of thermal energy to be transferred, a thermal energy transfer requirement may indicate an amount of thermal energy to be provided to or removed from a thermal customer to bring the thermal customer within its target operating temperature range. Accordingly, comparing the thermal energy transfer requirement with an achievable thermal energy transfer in an operating mode may comprise, for each thermal circuit in the operating mode: obtaining an indication of thermal energy availability in the thermal circuit, obtaining an indication of thermal energy demand in the thermal circuit, and comparing the indicated thermal energy availability with the indicated thermal energy demand.

[0168] Comparing the thermal energy transfer requirement with an achievable thermal energy transfer may be performed before the energy costs are obtained, and operating modes indicated as accepted or rejected based on the comparing the thermal energy transfer requirement with an achievable thermal energy transfer. In this case, the accepted operating modes include the one or more operating modes for which energy costs are to be determined. Accordingly, the rejection of operating modes on the basis of their achievable thermal energy transfer may be determined before obtaining the associated energy cost, and so the determination of the energy cost associated with rejected operating modes may be avoided This may improve computational efficiency, particularly where obtaining an energy cost associated with an operating mode uses more computing resource than determining whether an operating mode is accepted or rejected. In some examples, the energy cost is not obtained for rejected operating modes.

[0169] The indication of compliance of the operating mode with the thermal energy transfer requirement may indicate whether or not the thermal energy transfer requirement is satisfied in the operating mode. In some examples, when the operating mode does not satisfy the thermal energy transfer requirement, the indication of compliance of the operating mode with the thermal energy transfer requirement may indicate a degree to which the operating mode does not satisfy the thermal energy transfer requirement. The information regarding the degree to which the operating mode does not satisfy the thermal energy transfer requirement may be used in selecting an operating mode. For example, if it is determined that none of the operating modes satisfy the thermal energy transfer requirement, an operating mode that comes closest to satisfying the thermal energy transfer requirement may be selected

[0170] In some examples, where the operating mode does not satisfy the thermal energy transfer requirements, the indication of compliance of the operating mode with the thermal energy transfer requirement may indicate a difference between a target thermal energy transfer rate and an achievable thermal energy transfer rate in the operating mode In some examples, where the operating mode does not satisfy the thermal energy transfer requirements, the indication of compliance of the operating mode with the thermal energy transfer requirement may indicate a difference between an amount of energy to be transferred according to the thermal energy transfer requirement and an amount of energy transferred (or transferrable) in the operating mode.

[0171] As described above, the indication of compliance may indicate whether or not a particular operating mode is consistent with thermal energy flow directions indicated by one or more thermal energy transfer requirements (e.g., whether the mode provides thermal energy to components that have a thermal energy deficit, and removes thermal energy from components that have excess thermal energy) Alternatively, or additionally, the indication of compliance may indicate whether or not one or more target thermal energy transfer requirements, in terms of thermal energy transfer amounts / rates, are met in the operating mode Alternatively, or additionally, the indication of compliance may indicate a degree to which one or more target thermal energy transfer requirements are met in the operating mode.

[0172] In some examples, the indication of compliance may include both the indication regarding a direction of thermal energy flow and an indication based on energy transfer amounts / rates. In some examples, the determination of compliance based on direction of thermal energy flow may be performed before the determination based on thermal energy transfer amounts / rates In some examples, candidate operating modes may be determined based on direction of thermal energy flow, and the determination based on thermal energy transfer amounts / rates may be performed for the candidate operating modes (e.g., the determination based on thermal energy transfer amounts / rates may be performed only for the candidate operating modes, such that the determination based on thermal energy transfer amounts / rates is not performed for operating modes that are not determined to be candidate operating modes). This may improve computational efficiency In particular, where the assessment of compliance based on energy transfer amounts / rates requires more computational resource than the assessment of compliance based on direction of thermal energy flow, the more computationally costly assessment may be avoided for operating modes that do not meet the requirements according to the less computationally costly assessment.

[0173] The method 600 shown in FIG. 6 is suitable for rapidly considering a large number of operating modes in order to select an operating mode to be implemented. This may be particularly beneficial for real-time use in a vehicle with limited on-board computing resources, but other possibilities are contemplated. For example, an assessment of compliance could be based on energy transfer rates / amounts before or instead of an assessment based on direction of thermal energy flow In some examples a first assessment of compliance could be carried out (e.g., with regard to directions of thermal energy flow), an energy cost could be calculated (e g., for modes that are determined to have compliant directions of thermal energy flow), and a further assessment of compliance could be carried out (e.g., based on the amount / rate of thermal energy transfer). In some examples, an energy cost may be obtained for all available operating modes, and compatibility with thermal energy transfer requirements may be determined after the energy costs are obtained. In some examples, an operating mode may be chosen based on the energy cost, and the chosen operating mode may then be assessed against the thermal energy transfer requirements. If the chosen mode is determined to comply with the thermal energy transfer requirements, it may then be selected as the operating mode to be implemented. However, if the operating mode is determined not to comply with the thermal energy transfer requirements, a next mode may be selected based on the energy costs, and that operating mode may then be assessed for compliance with the thermal energy transfer requirements. This process may be repeated until a compliant operating mode is found or until all modes have been determined to be non-complaint. If all modes are non-compliant an operating mode to be implemented may be selected based on an energy cost, a degree of compliance with the thermal energy transfer requirements, or some combination of these.

[0174] In some examples, each stage may happen in turn. For example, in an arrangement that produces a list of candidate operating modes based on direction of transfer of thermal energy, followed by acceptance or rejection of operating modes based on an amount / rate of thermal energy transfer, followed by a selection of an operating mode based on energy costs, each stage may complete before the next begins, such that the list of candidate operating modes is determined before carrying out the assessment based on amount / rate of thermal energy transfer This assessment may be completed before the energy costs associated with the operating modes are determined.

[0175] Alternatively, the stages may be performed in parallel. For example, when a mode is determined to be a candidate operating mode the assessment based on amount / rate of thermal energy transfer may be performed immediately, while other operating modes continue to be assessed with regard to direction of transfer of thermal energy Similarly, when an operating mode is determined to comply with the amount / rate of thermal energy transfer, the energy cost associated with that operating mode may be calculated immediately, while the assessment of other operating modes with regard to amount / rate of thermal energy transfer continues to be assessed.

[0176] In some examples the method may include determining one or more unavailable operating modes and excluding these from consideration. For example, the outside heat exchanger may not function below a certain temperature. In such a case, when it is determined that the outside heat exchanger does not function, e.g., due to very a low temperature, operating modes that use the outside heat exchanger may be omitted from consideration. More generally, if a condition is met that is determined to render an operating mode unavailable, the operating mode may be removed from consideration. In some examples, the determination of unavailable operating modes may be performed before obtaining an indication of compliance of the operating mode with thermal energy transfer requirements and / or before obtaining an energy cost associated with the operating mode However, the order of these operations may be changed in some examples.

[0177] Certain methods and systems as described herein may be implemented by one or more processors that process program code that is retrieved from a storage medium, such as non-transitory storage medium. FIG. 7 shows an example of a device 700 comprising a computer-readable storage medium (e.g. memory device 110) coupled to at least one processor 108. The computer-readable medium 110 can be any media that can contain, store, or maintain programs and data for use by or in connection with an instruction execution system Computer-readable medium 110 can comprise any one of many physical media such as, for example, electronic, magnetic, optical, electromagnetic, or semiconductor media. More specific examples of suitable machine-readable media include, but are not limited to, a hard drive, a random-access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory, or a portable disc.

[0178] In FIG. 7, the computer-readable storage medium 110 comprises program code 112 to perform a method 500 corresponding to the embodiment shown in FIG. 5, that is: obtaining 502 one or more energy costs, respectively associated with one or more operating modes of the thermal management system 100; selecting 504 an operating mode based on the one or more obtained energy costs; and providing 506 an output indicating the selected operating mode.

[0179] The device 700 may be included in controller 106 of an electric vehicle 200, as illustrated in FIG. 2, for example

[0180] It will be appreciated that various changes and modifications can be made to the embodiments of the present invention without departing from the scope of the present application.

Claims

CLAIMS1 An electric vehicle thermal management system control system for controlling a thermal management system of an electric vehicle, the thermal management system having a plurality of operating modes, the control system comprising one or more processors collectively configured to: obtain, for each operating mode of two or more operating modes of the thermal management system, an energy cost associated with the operating mode; select an operating mode based on the obtained energy costs; and provide an output indicating the selected operating mode.2 The control system of claim 1 , wherein the selection of an operating mode comprises selection of an operating mode having a lowest energy cost among the two or more operating modes.3 The control system of claim 1 or 2, wherein the one or more processors are collectively configured to: receive thermal energy information for a plurality of components of the electric vehicle, the thermal energy information indicating at least one thermal energy transfer reguirement of at least a first component of the plurality of components; and obtain, for each operating mode of the plurality of operating modes of the thermal management system, an indication of compliance of the operating mode with the at least one thermal energy transfer requirement, wherein the selection of an operating mode is based on the obtained energy costs and the indication of compliance of the operating mode with the at least one thermal energy transfer requirement.4 The control system of claim 3, wherein the selection of an operating mode comprises selecting one or more operating modes from the plurality of operating modes based on the respective indications of compliance.5 The control system of claim 3 or 4, wherein the one or more processors are collectively configured to: obtain, based on the thermal energy information, an indication of one or more components that are requesting thermal energy and one or more components that have excess thermal energy, and determine candidate operating modes, wherein each candidate operating mode is an operating mode of the thermal management system that provides heat to each component that is requesting thermal energy and removes heat from each component that has excess thermal energy, wherein the indication of compliance of an operating mode with the at least one thermal energy transfer requirement is based on whether or not the operating mode is a candidate operating mode.6 The control system of claim 5, wherein the candidate operating modes are determined before the energy costs are obtained, and the candidate operating modes include the two or more operating modes.7 The control system of any one of claims 3 to 6, wherein the indication of compliance of an operating mode with the at least one thermal energy transfer requirement is based on the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer in the thermal management system according to the operating mode.8 The control system of claim 7, wherein: each operating mode is associated with a respective set of thermal circuits, each thermal circuit comprising a group of the components that are in mutual thermal communication via the thermal management system in the operating mode, and the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer in an operating mode comprises the determination, for each thermal circuit in the set of thermal circuits associated with the operating mode, whether an achievable thermal energy transfer in the thermal circuit is consistent with at least one thermal energy transfer requirement of components in the thermal circuit.9 The control system of claim 7 or 8, wherein the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer is performed before the energy costs are obtained, wherein operating modes are accepted or rejected based on the comparison of the at least one thermal energy transfer requirement with an achievable thermal energy transfer, and the accepted operating modes include the two or more operating modes10 The control system of any one of claims 1 to 9, wherein the energy cost of an operating mode comprises a thermal energy cost value representing an amount of thermal energy transferred off the vehicle in that operating mode and an actuator energy cost value representing an energy cost associated with operating the thermal management system in that operating mode.11 The control system of claim 10, wherein the actuator energy cost value associated with an operating mode is representative of at least one of: an energy cost of operating a compressor according to that operating mode; a valve actuation energy cost associated with that operating mode; a vehicle drag cost associated with operation of a heat exchanger according to that operating mode; an energy cost of operating a pump according to that operating mode; and an energy cost of operating a fan according to that operating mode.12 A method for operating a control system for controlling a thermal management system of an electric vehicle, the thermal management system having a plurality of operating modes, the method comprising: obtaining, for each operating mode of two or more operating modes of the thermal management system, an energy cost associated with the operating mode; selecting an operating mode based on the obtained energy costs; and providing an output indicating the selected operating mode.13 Computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform the method of claim 12.14 A computer readable medium comprising computer readable instructions that, when executed by a processor, cause performance of the method of claim 12.15 A vehicle comprising: the control system, of any one of claims 1 to 11; and a thermal management system communicatively coupled to the control system.

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