Control of vehicle thermal managment systems

Abstract

Aspects of the present invention relate to a method for controlling a thermal management system of an electric vehicle. The method includes obtaining thermal energy information for a plurality of components of the electric vehicle, the thermal energy information indicates a thermal energy transfer requirement for at least one respective component. For each of one or more operating modes of the thermal management system, it is determined whether the operating mode is a candidate operating mode. In each candidate operating mode, the thermal management system is arranged to remove thermal energy from components that are indicated by the thermal energy transfer requirement as having excess thermal energy, and is arranged to provide thermal energy to components that are indicated by the thermal energy transfer requirement as requesting thermal energy. A recommended operating mode is selected from among the candidate operating modes, the recommended operating mode to be implemented in the thermal management system. An output indicating the recommended operating mode is provided.

Description

[0001] CONTROL OF VEHICLE THERMAL MANAGEMENT SYSTEMS

[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] Disclosed arrangements provide a method for controlling a thermal management system of an electric vehicle, the method comprising: determining, for each of one or more operating modes of the thermal management system whether, in the operating mode, thermal energy is removed from components that have excess thermal energy, and thermal energy is provided to components that have a thermal energy deficit; and selecting, based on the determining, a recommended operating mode.

[0011] Accordingly, operating modes may be efficiently filtered to remove from consideration operating modes that do not provide heat flow in a desired direction.

[0012] An aspect of the invention provides a method for controlling a thermal management system of an electric vehicle, the method comprising: obtaining thermal energy information for a plurality of components of the electric vehicle, the thermal energy information indicating a thermal energy transfer requirement for at least one respective component; determining, for each of one or more operating modes of the thermal management system, whether the operating mode is a candidate operating mode, wherein, in each candidate operating mode, the thermal management system is arranged to remove thermal energy from components that are indicated by the thermal energy transfer requirement as having excess thermal energy, and is arranged to provide thermal energy to components that are indicated by the thermal energy transfer requirement as requesting thermal energy; selecting a recommended operating mode from among the candidate operating modes, the recommended operating mode to be implemented in the thermal management system; and providing an output indicating the recommended operating mode.

[0013] Accordingly, a selection of candidate operating modes may be performed to reject operating modes that do not provide heat to components that request thermal energy and remove heat from components that have excess thermal energy. This may simplify the selection by reducing the number of operating modes to be considered in the selection.

[0014] In some examples, selecting the recommended operating mode comprises evaluating each operating mode from among the candidate operating modes and selecting the recommended operating mode based on the evaluating.

[0015] Accordingly, evaluating may be unnecessary for rejected operating modes. In some examples, for one or more of the candidate operating modes the evaluating comprises at least one of: evaluating whether the operating mode is compatible with the thermal energy transfer requirements, evaluating a degree to which the operating mode is compatible with the thermal energy transfer requirements, and evaluating an energy cost associated with the operating mode. The energy cost may be based on one or more of: an energy usage associated with the operating mode, and thermal energy transferred to the environment according to the operating mode.

[0016] Accordingly, an operating mode may be selected taking into account suitability for meeting requirements of the system, and / or an energy cost associated with the operating mode.

[0017] In some examples, for one or more of the candidate operating modes the evaluating comprises at least one of: assessing a thermal energy transfer to an environment of the vehicle in the one or more candidate operating mode, assessing an energy cost associated with the one or more candidate operating modes, assessing whether thermal energy transfers requested by components are achievable in the one or more candidate operating modes.

[0018] Accordingly, the selection of an operating mode may take into account one or more energy efficiency factors.

[0019] In some examples, evaluating a candidate operating mode uses more computing resource than determining whether the operating mode is a candidate operating mode.

[0020] Accordingly, the (relatively) computationally demanding evaluation of an operating mode may be avoided for operating modes that do not provide heat to components that request thermal energy and remove heat from components that have excess thermal energy.

[0021] In some examples, selecting the recommended operating mode comprises evaluating each operating mode from among the candidate operating modes and selecting the recommended operating mode based on the evaluating, wherein for one or more of the candidate operating modes the evaluating comprises obtaining an energy cost associated with a respective operating mode of the one or more of the candidate operating modes.

[0022] 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.

[0023] In some examples, the energy cost of an operating mode comprises at least one of a thermal energy cost value representing an amount of thermal energy transferred off the electric 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.

[0024] 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 electric vehicle may be selected). In particular, 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 electric 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.

[0025] 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.

[0026] 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. In some examples, the thermal energy information indicates amounts of thermal energy to be transferred to or from respective components requesting thermal energy transfers, and thermal energy transfers requested by components are achievable in a candidate operating mode if, in the candidate operating mode, amounts of energy transferable to respective components correspond with the respective indicated amounts of thermal energy.

[0027] Accordingly, the selection of the operating mode may be based on whether or not, or how well, the operating mode satisfies the thermal energy transfer requirement.

[0028] In some examples, the thermal energy information indicates rates of thermal energy transfer to or from respective components requesting thermal energy transfers, and thermal energy transfers requested by components are achievable in a candidate operating mode if, in the candidate operating mode, energy is transferable to respective components at rates that correspond with the respective indicated rates of thermal energy transfer.

[0029] Accordingly, the selection of the operating mode may be based on whether or not, or how well, the operating mode satisfies the thermal energy transfer requirement.

[0030] In some examples, the components requesting thermal energy transfers have respective target operating temperature ranges, and thermal energy transfers requested by components are achievable in a candidate operating mode if, in the candidate operating mode, the amounts of energy transferable to respective components result in the respective components having a temperature in their respective target operating temperature ranges.

[0031] Accordingly, the selection of an operating mode may take into account whether an operating mode is appropriate to bring temperatures of components within their respective target temperature ranges.

[0032] In some examples, the thermal energy information indicates target thermal energy transfers of components, and assessing whether thermal energy transfers requested by components are achievable in a candidate operating mode comprises: obtaining a thermal energy balance value based on aggregating the target thermal energy transfers of components in thermal communication in the candidate operating mode, and determining, based on the thermal energy balance value, whether the target thermal energy transfers are satisfied in the candidate operating mode.

[0033] Accordingly, the selection of an operating mode may take into account target thermal energy transfers and whether (or how well) the target thermal energy transfers are achieved by the operating mode.

[0034] In some examples a target thermal energy transfer includes at least one of a target amount of thermal energy to be transferred, or a target rate of thermal energy transfer.

[0035] In some examples, the thermal energy transfer requirement for a respective component comprises at least one of: an indication that thermal energy is requested by the respective component; an indication that the respective component has excess thermal energy; an indication that the respective component is able to either receive or supply thermal energy; or an indication that no thermal energy is to be transferred from or to the respective component.

[0036] Accordingly, the selection of the operating mode may take into account the thermal energy status of the components, and may allow for components that have capacity to act as either a source or a sink. Further, changes in temperature may be avoided for components that are at their target operating temperature (e.g. in their target operating temperature range). As such, in some examples, a component may have a target operating temperature range, and the thermal energy transfer requirement may indicate that the component is useable as a source of thermal energy and is useable as a sink of thermal energy when the component is in its target operating temperature range. Put another way, when the component is in its target operating temperature range it may be indicated as both a potential source and a potential sink for thermal energy.

[0037] In some examples, an indication that the respective component is requesting thermal energy corresponds with a state in which thermal energy is to be supplied to the respective component; an indication that the respective component has excess thermal energy corresponds with a state in which thermal energy is to be extracted from the respective component; and an indication that the respective component is able to either receive or supply thermal energy corresponds with a state in which the respective component is within a target operating temperature range. Accordingly, the indication may provide information regarding a thermal energy transfer that is to be performed to improve the operating condition of the respective component. In addition, the indication may indicate that the respective component has capacity to act as either a source or a sink of thermal energy. Taking this capacity into account may facilitate selection of an energy efficient operating mode.

[0038] In some examples, an indication that the respective component is requesting thermal energy corresponds with a state in which the respective component is below a target operating temperature range; an indication that the respective component has excess thermal energy corresponds with a state in which the respective component is above the target operating temperature range; and an indication that thermal energy may be supplied to or extracted from the respective component may correspond with a state in which the respective component is within the target operating temperature range.

[0039] Accordingly, the indication may allow a determination that the respective component is too hot or too cold. Further, when the respective component is in its target operating temperature range, it is able to receive excess thermal energy from other components, or to supply thermal energy to other components.

[0040] 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.

[0041] In some examples, the respective component may be a first thermal customer, and the thermal energy transfer requirement may comprise thermal energy transfer requirements for a plurality of thermal customers, the plurality of thermal customers comprising the first thermal customer. The thermal customers may 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.

[0042] Accordingly, the thermal management system may provide an energy efficient approach to controlling the temperature of thermal customers.

[0043] In examples, the thermal energy transfer requirement indicates, for each thermal customer, whether: thermal energy is to be removed from the thermal customer, the thermal customer has excess thermal energy, or the thermal customer does not request transfer of energy (e.g. if the thermal customer is operating within an associated target temperature range).

[0044] The thermal customers may comprise one or more of: a traction battery; an electric drive unit; and a cabin of the vehicle.

[0045] Accordingly, the heat management system may manage the temperature of one or more of a traction battery; an electric drive unit; and a cabin.

[0046] In some examples, when the respective component is in its target operating temperature range, the thermal energy transfer requirement comprises the indication that the respective component is able to either receive or supply thermal energy.

[0047] Accordingly, when the respective component is in its target operating temperature range, it may be used to store excess thermal energy, or may be used as a source of thermal energy.

[0048] The respective component may be designated as a thermal storage component, where a thermal storage component is a component that has an associated operating temperature range, and that is to be used to store excess thermal energy when the thermal storage component is within its target operating temperature range.

[0049] Accordingly, the respective component may be used as a reservoir of thermal energy. Thus, excess thermal energy in the system may be stored by the respective component. When another component of the system has a deficit of thermal energy, some of the stored thermal energy may be provided from the respective component to the other component. This provides efficiency, by storing excess energy until it is needed. Storing excess thermal energy in the respective component and supplying thermal energy from the respective component may be carried out such that the respective component remains within its target operating temperature range.

[0050] The respective component may be selected from a traction battery or an electric drive unit.

[0051] A traction battery or an electric drive unit may have sufficient heat capacity and a sufficiently broad target operating temperature range to allow thermal energy to be stored until requested by other components of the system without degrading the performance of the traction battery or electric drive unit.

[0052] In some examples, when the respective component is in its target operating temperature range, the thermal energy transfer requirement comprises the indication that no thermal energy is to be transferred from or to the respective component. For example, when the component is not designated as a thermal storage component.

[0053] Accordingly, examples allow for a component having a target operating temperature range that is not to be used to store excess thermal energy.

[0054] In some examples, an indication that the respective component is requesting thermal energy corresponds with a state in which thermal energy is to be supplied to the respective component; an indication that the respective component has excess thermal energy corresponds with a state in which thermal energy is to be extracted from the respective component; and an indication that no thermal energy is to be transferred from or to the respective component corresponds with a state in which the respective component is within a target operating temperature range.

[0055] Accordingly, the indication may provide information regarding a thermal energy transfer that is to be performed to improve the operating condition of the respective component. In addition, the indication may indicate that the respective component is not to act as either a source or a sink of thermal energy. This allows for components (e.g. thermal customers) that are not used to store excess thermal energy.

[0056] In some examples, an indication that the respective component is requesting thermal energy corresponds with a state in which the respective component is below a target operating temperature range; an indication that the respective component has excess thermal energy corresponds with a state in which the respective component is above the target operating temperature range; and an indication that no thermal energy is to be transferred from or to the respective component may correspond with a state in which the respective component is within the target operating temperature range.

[0057] Accordingly, the indication may allow a determination that the respective component is too hot or too cold. Further, when the respective component is in its target operating temperature range, it can be indicated as not able to receive excess thermal energy from other components, or to supply thermal energy to other components. This allows for components (e.g. thermal customers) that are not used to store excess thermal energy.

[0058] In examples, the respective component is not designated as a thermal storage component.

[0059] Accordingly, not all components are treated as thermal storage components. This provides flexibility in designing the thermal management system.

[0060] The respective component may be a cabin, such that the cabin is not designated as a thermal storage component.

[0061] Accordingly, temperature fluctuations resulting from using the cabin to store thermal energy may be avoided.

[0062] In some examples, the thermal energy transfer requirement for the respective component comprises a field, the field has one of: a first value to indicate that thermal energy is requested by the respective component, a second value to indicate that the respective component has excess thermal energy, a third value to indicate, when the respective component is useable to store excess thermal energy, that the respective component is able to either receive or supply thermal energy, and the third value to indicate, when the respective component is not to be used to store excess thermal energy, that no thermal energy is to be transferred from or to the respective component. In some examples, the thermal energy transfer requirement for the respective component comprises a field, the field has one of: a first value to indicate that the respective component is below its target operating temperature range, a second value to indicate that the respective component is above its target operating temperature range, or a third value to indicate that the respective component is within its target operating temperature range.

[0063] In some examples, the field may store a high indicator when the respective component is above its target operating temperature range, a low indicator when the respective component is below its target operating temperature range, or an in-range indicator when the respective component is within its target operating temperature range.

[0064] Accordingly, a thermal energy transfer requirement associated with a component may be efficiently communicated within the system.

[0065] In some examples, the respective component is designated as a thermal storage component or not a thermal storage component. When the respective component is designated as a thermal storage component, the thermal energy transfer requirement for the respective component may comprise: an indication that thermal energy is requested by the respective component; an indication that the respective component has excess thermal energy; an indication that the respective component is able to either receive or supply thermal energy; and when the respective component is designated as not a thermal storage component, the thermal energy transfer requirement for the respective component comprises: an indication that thermal energy is requested by the respective component; an indication that the respective component has excess thermal energy; or an indication that no thermal energy is to be transferred from or to the respective component.

[0066] Accordingly, a thermal energy transfer requirement in an efficient manner in a system that can include components designated as thermal storage components and components not designated as thermal storage components.

[0067] In some examples, the thermal energy transfer requirement for a component comprises at least one of: an indication of an amount of thermal energy to be supplied to or extracted from the component.

[0068] 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.

[0069] In some examples, the thermal energy transfer requirement for a component comprises at least one of: an indication of a rate at which thermal energy is to be supplied to or extracted from the component.

[0070] Accordingly, the rate at which thermal energy is to be supplied to or extracted from the component can be taken into account when selecting the operating mode.

[0071] In some examples, the 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.

[0072] Accordingly, the selection of the operating mode may be based on whether a component is too hot or too cool in order to correct the temperature of the component. In some examples, an amount or rate of thermal energy to be transferred to / from a component according to the thermal energy transfer requirement may be based on the difference between the current temperature of the component and its target operating temperature range.

[0073] In some examples, each operating mode is associated with: a respective coolant configuration of a cooling system of the thermal management system, wherein each coolant configuration defines a direction of flow of thermal transfer fluid to at least one component of the cooling system; and a respective refrigerant configuration of a refrigerant system of the thermal management system, wherein each refrigerant configuration defines a direction of flow of thermal transfer fluid to at least one component of the refrigerant system.

[0074] Accordingly, thermal communication between the components may be controlled differently in different modes, to provide flexibility in meeting the thermal requirements of the system.

[0075] In some examples, the thermal management system comprises a cooling system and a refrigerant system, the cooling system is operable in a plurality of coolant configurations, each coolant configuration defining a direction of flow of thermal transfer fluid to at least one component of the cooling system, the refrigerant system is operable in a plurality of refrigerant configurations, each refrigerant configuration defining a direction of flow of thermal transfer fluid to at least one component of the refrigerant system, each operating mode is associated with a respective coolant configuration and a respective refrigerant configuration.

[0076] Accordingly, it is possible to take into account various combinations of cooling system configurations and refrigerant system configurations. According to embodiments, it is possible to efficiently assess each operating mode, even when the number of possible combinations of coolant and refrigerant configurations becomes large.

[0077] The cooling system may comprise, or be in thermal communication with, at least one of a traction battery; an electric drive unit; a radiator; and a coolant heater. The refrigerant system may comprise, or be in thermal communication with, at least one of a cabin air conditioning unit; an outside heat exchanger; a condenser; and one or more internal evaporators.

[0078] In some examples, each operating mode is further associated with a respective state of a thermal link component of the thermal management system, the thermal link component being 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.

[0079] Accordingly, the state (e.g. on or off) of a thermal link component, such as a chiller, may be taken into account in addition to combinations of cooling system configurations and refrigerant system configurations. According to embodiments, it is possible to efficiently assess each operating mode taking into account the state of a thermal link component, even where this leads to the number of operating modes becoming large.

[0080] 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.

[0081] Accordingly, an operating mode of the thermal management system may be selected based on the 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.

[0082] In some examples, the method may include obtaining mode information for the operating modes, the mode information comprising, for each operating mode, a thermal criterion for at least a first component of the plurality of components, the thermal criterion indicating whether the operating mode is compatible with the first component being above, below, or within its target operating temperature range. The thermal energy information may comprise, for at least the first component, a thermal indicator indicative of whether the component is above, below or within a target operating temperature range of the first component. Determining whether the operating mode is a candidate operating mode may comprise comparing the mode information with the thermal indicator. For example, comparing the thermal criterion corresponding with a thermal customer with the thermal indicator of the thermal customer.

[0083] Accordingly, it is possible to efficiently determine whether the operating mode is a candidate operating mode.

[0084] The first component may be the respective component described above.

[0085] 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 determine, for each of one or more operating modes of the thermal management system whether, in the operating mode, thermal energy is removed from components that have excess thermal energy, and thermal energy is provided to components that have a thermal energy deficit; and select, based on the determining, a recommended operating mode.

[0086] 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 thermal energy information for a plurality of components of the electric vehicle, the thermal energy information indicating a thermal energy transfer requirement for at least one respective component; determine, for each of one or more operating modes of the thermal management system, whether the operating mode is a candidate operating mode, wherein, in each candidate operating mode, the thermal management system is arranged to remove thermal energy from components that are indicated by the thermal energy transfer requirement as having excess thermal energy, and is arranged to provide thermal energy to components that are indicated by the thermal energy transfer requirement as requesting thermal energy; select a recommended operating mode from among the candidate operating modes, the recommended operating mode to be implemented in the thermal management system; and provide an output indicating the recommended operating mode.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] The computer readable medium may be a non-transitory computer readable medium.

[0091] Some examples provide a vehicle comprising: any of the control systems described herein; and a thermal management system communicatively coupled to the control system.

[0092] In some examples, the thermal management system comprises a cooling system and a refrigerant system, the cooling system is operable in a plurality of coolant configurations, each coolant configuration defining a direction of flow of thermal transfer fluid to at least one component of the cooling system, the refrigerant system is operable in a plurality of refrigerant configurations, each refrigerant configuration defining a direction of flow of thermal transfer fluid to at least one component of the refrigerant system.

[0093] In some examples, each operating mode is associated with a respective coolant configuration and a respective refrigerant configuration.

[0094] In some examples, the cooling system comprises, or is in thermal communication with, at least one of a traction battery; an electric drive unit; a radiator; and a coolant heater, the refrigerant system comprises at least one of a cabin air conditioning unit; an outside heat exchanger; a condenser; and one or more internal evaporators.

[0095] In some examples, the thermal management system comprises a thermal link component, the thermal link component is switchable between a first state and a second state, in the first state the thermal link component is configured to provide thermal communication between the cooling system and the refrigerant system, in the second state the thermal link component is configured not to provide thermal communication between the cooling system and the refrigerant system, and each operating mode is associated with a respective state of the thermal link component.

[0096] 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.

[0097] BRIEF DESCRIPTION OF THE DRAWINGS

[0098] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which, in accordance with embodiments of the invention:

[0099] FIG. 1 illustrates a thermal management system for an electric vehicle;

[0100] FIG. 2 illustrates a vehicle including the system of FIG. 1 ;

[0101] FIG. 3 illustrates a schematic representation of a powertrain thermal management system;

[0102] FIG. 4A to FIG. 4F illustrate example configurations of the thermal management;

[0103] FIG. 5 illustrates a method for controlling a thermal management system of an electric vehicle;

[0104] FIG. 6 illustrates a method for controlling a thermal management system of an electric vehicle; and

[0105] FIG. 7 illustrates a control system suitable for performing the methods described herein. DETAILED DESCRIPTION

[0106] 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). Prior to selection of the operating mode, it may be determined for one or more operating modes whether the operating mode removes thermal energy from components that have excess thermal energy and provides thermal energy to components that request thermal energy (have a thermal energy deficit). Accordingly, candidate operating modes may be determined efficiently.

[0107] In some examples, an operating mode may be selected based on an energy cost associated with the operating mode (e.g . , an operating mode having a lowest energy cost). Thus, an energy based calculation may be performed for at least some candidate 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. The determination of an energy cost associated with modes that are not candidate operating modes may be avoided, providing computational efficiency when selecting an operating mode.

[0108] The selected operating mode can be output as a signal to provide an indication of a selected, or recommended, 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.

[0109] 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 100 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 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.

[0110] 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.

[0111] 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 110. The memory means is electrically coupled to the processing means. The memory means is configured to store instructions 1 12, and the processing means is configured to access the memory means and execute the instructions 112 stored thereon.

[0112] 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. 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.

[0113] The components of the electric vehicle 200 may have target operating temperature ranges, and operating a component outside of an associated target operating temperature range may lead to increased power consumption by the component or by the electric vehicle 200. 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.

[0114] The thermal management system 100 is operable as a source (supply) or sink of thermal energy to components of the vehicle 200. 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.

[0115] 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.

[0116] 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. In some examples the cooling system comprises, or is in thermal communication with, at least one of a traction battery; an electric drive unit; a radiator (second heat exchanger 308); and a coolant heater.

[0117] 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, excess thermal energy may be transferred from powertrain components for use in heating the cabin of the vehicle. In some embodiments, the first heat exchanger 306 may be bi-directional 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 reduced 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.

[0118] 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.

[0119] 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.

[0120] Bypass conduits may be provided for one or more components of the first 314 or second 316 coolant loops. A bypass conduit may controllably opened or closed by a valve to control the supply of coolant to the respective component. For example, 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.

[0121] 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. In some examples, the front 202a and rear 202b electric drive units may each be provided with a respective bypass conduit (not shown) to selectively bypass the respective electric drive unit 202a, 202b, accordingly, transfer of thermal energy to or from the front 202a and rear 202b electric drive units may be permitted when the respective electric drive unit 202 is not bypassed and may be avoided when the respective electric drive unit 202 is bypassed.

[0122] 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.

[0123] 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.

[0124] 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 I ink 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. For example, the thermal link component may be placed in the first state by including the thermal link component in both the coolant circulation loop and the refrigerant circuit (e g., by not bypassing the thermal link component in the cooling system and not bypassing the thermal link component in the refrigerant system). Similarly, the thermal link component may be placed in the second state by bypassing the thermal link component in one or both of the cooling system and the refrigerant system.

[0125] 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.

[0126] 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.

[0127] 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. In some examples, the refrigerant system may have a plurality of refrigerant configurations, and each refrigerant configuration defines a direction of flow of thermal transfer fluid to at least one component of the refrigerant system.

[0128] In examples, the thermal management system 100 may include a cooling system and a refrigerant system. The cooling system may be operable in a plurality of coolant configurations, each coolant configuration defining a direction of flow of thermal transfer fluid to at least one component of the cooling system, and each operating mode may be associated with a respective coolant configuration. In some examples, the refrigerant system may be operable in a plurality of refrigerant configurations, each refrigerant configuration defining a direction of flow of thermal transfer fluid to at least one component of the refrigerant system, where each operating mode is associated with a respective refrigerant configuration. In some examples, each operating mode may be associated with a respective coolant configuration and a respective refrigerant configuration. In some examples, each operating mode may further be associated with a respective state of a thermal link component of the thermal management system 100, such that the operating mode depends on whether or not a coolant circulation loop is in thermal communication with a refrigerant circuit via the thermal link component.

[0129] 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.

[0130] 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. For illustration purposes, the refrigerant circuit 408 is shown as having an internal evaporator 404 and an outside heat exchanger 406, but the refrigerant circuit 408 may include other additional or alternative components.

[0131] 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:

[0132] 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;

[0133] FIGS. 4C and 4D: different from FIG 3 and 4A, having ports 5 and 8 interconnected and ports 6 and 7 interconnected; and FIG. 4E and 4F: as for FIGS. 4C and 4D, except ports 1 and 4 are interconnected, as are ports 2 and 3.

[0134] 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 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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, 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. Other energy costs may be considered in selecting an operating mode, as described in more detail below. 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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 table-based, rules- based, or similar, approach.

[0144] Where a large number of operating modes are to be considered, detailed consideration of each operating mode (e.g., by obtaining energy costs for every operating mode) may be computationally prohibitive. 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.

[0145] According to examples herein, candidate operating modes are determined. Candidate operating modes are operating modes in which thermal energy is removed from components that have excess thermal energy, and thermal energy is provided to components that have a thermal energy deficit. A recommended operating mode is then selected based on the determination of candidate operating modes. Accordingly, the candidate operating modes may form a shortlist of operating modes from which a recommended operating mode may be selected.

[0146] This may be more computationally efficient than directly selecting a single operating mode from among the full set of operating modes. This approach may be particularly beneficial, albeit not necessarily essential, where there are a large number of operating modes, e.g., by reducing the number of operating modes that are to be assessed in detail when selecting a recommended operating mode. In some examples, 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 temperature-based, table-based, or rules-based approaches.

[0147] FIG. 5 illustrates a method 500 for controlling a thermal management system 100 of an electric vehicle 200. At operation 502 thermal energy information is obtained. The thermal energy information relates to a plurality of components of the electric vehicle 200. The thermal energy information indicates respective thermal energy transfer requirements for one or more respective components of the plurality of components (e.g . , thermal energy transfer requests / demands by thermal customers).

[0148] Candidate operating modes are determined at operation 504 from among one or more of the operating modes. An operating mode is a candidate operating mode if, in that operating mode, the thermal management system 100 is arranged to remove thermal energy from components that are indicated by the thermal energy transfer requirement as having excess thermal energy, and is arranged to provide thermal energy to components that are indicated by the thermal energy transfer requirement as requesting thermal energy (i.e. components that are indicated by the thermal energy transfer requirement as having a thermal energy deficit). Accordingly, candidate operating modes may be considered to be operating modes that have thermal energy transfer directions (i.e., providing thermal energy to, or removing thermal energy from components) that are consistent with the thermal energy transfer requirements. Accordingly, determining candidate operating modes 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).

[0149] In some examples, a candidate operating mode may be an operating mode that additionally does not transfer thermal energy to or from a component that is not to provide or receive thermal energy, according to an associated indication of the thermal energy transfer requirement. For example, if a component is in its target operating temperature range (or at its target operating temperature) and is not designated as a component that is to act as a store for excess thermal energy, the associated thermal energy transfer requirement may indicate that the component is not to receive or provide thermal energy.

[0150] At operation 506 a recommended operating mode may be selected from among the candidate operating modes. The selection may be based on an energy cost associated with the operating mode, for example.

[0151] At operation 508 an output is provided indicating the recommended operating mode (also referred to herein as selected operating mode) . The output may be provided as a signal to a module of the controller 106 to provide an indication of a recommended operating mode of the system. In some examples, the output causes the thermal management system 100 to transition to the selected operating mode. In some examples, the module of the controller 106 may be a hardware module, a software module, a routine, etc.

[0152] The thermal energy transfer requirement for at least a first component of the plurality of components, such as the respective component referred to above, comprises an indication of at least one of: that thermal energy is requested by the first component (e.g., the component has a deficit of thermal energy, is too cold, or is below its target operating temperature range); and an indication that the first component has excess thermal energy (e.g., the component is too hot, or is above its target operating temperature range).

[0153] In some examples, other thermal states of the component may be indicated by the thermal energy transfer requirement. For example, the thermal energy transfer requirement may indicate that the first component is able to either receive or supply thermal energy (e.g., the first component is available to act as either a source or a sink of thermal energy). For example, when the first component is within its target operating temperature range and has capacity to either provide thermal energy to other components, or to store excess thermal energy. In some examples, the thermal energy transfer requirement may indicate that the component is not to transfer thermal energy, for example where it is in its target operating temperature range but is not to be used as a store of excess thermal energy.

[0154] An indication that the first component is requesting thermal energy may correspond with a state in which thermal energy is to be supplied to the first component; an indication that the first component has excess thermal energy may correspond with a state in which thermal energy is to be extracted from the first component; and an indication that the first component is able to either receive or supply thermal energy corresponds with a state in which the first component is within a target operating temperature range (e.g., a target operating temperature range associated with the first component) but has capacity to either receive or shed thermal energy while staying in its target operating range.

[0155] An indication that the first component is requesting thermal energy may correspond with a state in which the first component is below its target operating temperature range; an indication that the first component has excess thermal energy corresponds with a state in which the first component is above its target operating temperature range; and an indication that thermal energy may be supplied to or extracted from the first component may correspond with a state in which the first component is within its target operating temperature range and again, with capacity to either receive or shed thermal energy while staying in its target operating range.

[0156] In some examples, the thermal energy transfer requirement of a component may indicate whether the component is above, below or within its target operating temperature range.

[0157] In addition to the thermal energy transfer requirements, the thermal energy information may describe the status of components of the electric vehicle 200. For example, the thermal energy information may indicate or describe one or more of temperatures of one or more of the components, an amount of thermal energy to be supplied to or extracted from one or more of the components, or a rate at which thermal energy is to be supplied to or extracted from one or more of the components. The one or more of the components may be the respective component. 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 associated with the component.

[0158] In some examples the thermal energy information may indicate temperatures of components, for example, and the thermal energy transfer requirements may be derived from the indicated temperatures and other information about the system, such as a lookup table storing target operating temperature ranges associated with the components, and / or information indicating whether a component is usable to store excess thermal energy. In this way, the thermal energy transfer requirements may be indicated by the thermal energy information without being explicitly included in the thermal energy information. In other examples, the thermal energy transfer requirements may be explicitly included in the thermal energy information.

[0159] The respective component may be a first thermal customer, and the thermal energy transfer requirement may comprise thermal energy transfer requirements for a plurality of thermal customers, the plurality of thermal customers comprising the first thermal customer. That is, the components having thermal energy transfer requirements in the thermal energy information may be thermal customers.

[0160] In some examples, the thermal energy transfer requirement indicates, for each thermal customer, whether: thermal energy is to be removed from the thermal customer, the thermal customer has excess thermal energy, or the thermal customer does not request transfer of energy (e.g. if the thermal customer is operating within an associated target temperature range).

[0161] Thermal customers may include one or more of: a traction battery; an electric drive unit; and a cabin air conditioning unit, for example.

[0162] In some examples, the respective component may be designated as a thermal storage component. A thermal storage component may be a component that has an associated operating temperature range, and that is to be used to store excess thermal energy when the thermal storage component is within its target operating temperature range. This may reduce the transfer of thermal energy off of the electric vehicle 200, instead retaining the thermal energy on the electric vehicle 200 for possible future use. Accordingly, if a component has a subsequent deficit in thermal energy, the previously stored excess thermal energy may be extracted from the thermal storage component and provided to a component having the deficit. This may, for example, avoid or reduce usage of the coolant heater 304 to address the thermal energy deficit, leading to a corresponding reduction in electrical energy drawn from the traction battery 204 to power the coolant heater 304.

[0163] One or both of a traction battery or an electric drive unit may be designated as a thermal storage component, for example.

[0164] In some examples, the respective component may be designated as not to be used as a thermal storage component. In that case, when the respective component is in its target operating temperature range, the thermal energy transfer requirement may comprise the indication that no thermal energy is to be transferred from or to the respective component.

[0165] Accordingly, where the respective component is designated as not to be used as a thermal storage component, an indication that the respective component is requesting thermal energy (e.g., it is below its target operating temperature range) may correspond with a state in which thermal energy is to be supplied to the respective component; an indication that the respective component has excess thermal energy (e.g., is above its target operating temperature range) may correspond with a state in which thermal energy is to be extracted from the respective component; and an indication that no thermal energy is to be transferred from or to the respective component may correspond with a state in which the respective component is within its target operating temperature range.

[0166] In some examples, where the respective component is designated as not to be used as a thermal storage component, an indication that the respective component is requesting thermal energy may correspond with a state in which the respective component is below a target operating temperature range; an indication that the respective component has excess thermal energy may correspond with a state in which the respective component is above its target operating temperature range; and an indication that no thermal energy is to be transferred from or to the respective component may correspond with a state in which the respective component is within a target operating temperature range.

[0167] In some examples a cabin of the electric vehicle 200 may be designated as not usable as a thermal storage component. This may help to avoid unwanted temperature changes in the cabin, for example.

[0168] Selecting the recommended operating mode may comprise evaluating each operating mode from among the candidate operating modes and selecting the recommended operating mode based on the evaluation. The evaluating may include one or more of: evaluating whether the operating mode is compatible with the thermal energy transfer requirements (e.g., with magnitudes of thermal energy transfers indicated by the thermal energy transfer requirements), evaluating a degree to which the operating mode is compatible with the thermal energy transfer requirements, and evaluating an energy cost associated with the operating mode. The energy cost may be based on one or more of: an energy usage associated with the operating mode, and thermal energy transferred to the environment according to the operating mode, for example.

[0169] In some examples, the evaluation may include assessing a thermal energy transfer to an environment of the vehicle in the one or more candidate operating mode, assessing an energy cost associated with the one or more candidate operating modes, assessing whether thermal energy transfers requested by components are achievable in the one or more candidate operating modes.

[0170] Where it is determined whether an operating mode is a candidate operating mode before performing an evaluation of the operating mode, the evaluating may be avoided for operating modes that are not candidate operating modes. Put another way, in some examples the evaluating may be carried out only for operating modes that are determined to be candidate operating modes.

[0171] In some examples, evaluating a candidate operating mode may use more computing resource (e.g., memory, processor cycles, etc.) than determining whether the operating mode is a candidate operating mode. Accordingly, the (relatively) computationally demanding evaluation of an operating mode may be avoided for operating modes that do not provide heat to components that request thermal energy and remove heat from components that have excess thermal energy.

[0172] In some examples, selecting the recommended operating mode comprises evaluating each operating mode from among the candidate operating modes and selecting the recommended operating mode based on the evaluation. For one or more of the candidate operating modes the evaluating may comprise obtaining an energy cost associated with a respective operating mode of the one or more of the candidate operating modes.

[0173] The method 500 shown in FIG. 5 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 also contemplated. In some examples, the method 500 may be repeated during operation of the electric vehicle 200 (e.g., while the electric vehicle 200 is driving) in order to reassess whether the current operating mode is still a desired operating mode. For example, method 500 may be repeated at regular intervals (e.g., intervals corresponding with a time step of the vehicle control system) to select an operating mode. In some examples, the method 500 may be performed in response to other triggers instead of, or in addition to, periodically. For example, the method 500 may be performed in response to a change in situation of the electric vehicle 200, such as a change in driving mode, or based on a change in average driving speed, etc. Similarly, the selecting may be performed, for example, if it is determined that the battery 204 is to be preconditioned, that is, heated in preparation for charging. In some examples, the selection of an operating mode as a recommended operating mode is based on comparing the thermal energy transfer requirements with an achievable thermal energy transfer in the thermal management system according to the operating mode.

[0174] In some examples, assessing whether thermal energy transfers requested by components are achievable in the one or more candidate operating modes may include assessing the thermal energy transfer requirement and the achievable thermal energy transfer separately for each thermal circuit of the operating mode.

[0175] 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.

[0176] The thermal energy transfer requirements may indicate one or more of respective amounts of thermal energy transfer requested by respective components requesting thermal energy transfers, and respective rates of transfer of thermal energy requested by respective components requesting thermal energy transfers. 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.

[0177] In some examples, thermal energy transfers requested by components are achievable in a candidate operating mode if, in the candidate operating mode, amounts of energy transferable to respective components correspond with the respective indicated amounts of thermal energy. In some examples, thermal energy transfers requested by components are achievable in a candidate operating mode if, in the candidate operating mode, energy is transferable to respective components at rates that correspond with the respective indicated rates of thermal energy transfer.

[0178] 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.

[0179] 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.

[0180] 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.

[0181] 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 mode complies with all of the thermal energy transfer requirements.

[0182] 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 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.

[0183] In some examples, selecting a recommended operating mode may include determining 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, a degree to which the operating mode does not satisfy the thermal energy transfer requirement may be determined. The information regarding the degree to which the operating mode does not satisfy the thermal energy transfer requirement may be used in selecting a recommended 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.

[0184] In some examples, selecting a recommended operating mode may include, where the operating mode does not satisfy the thermal energy transfer requirements, determining a difference between a target thermal energy transfer rate and an achievable thermal energy transfer rate in the operating mode. In some examples, selecting a recommended operating mode may include, where the operating mode does not satisfy the thermal energy transfer requirements, determining a difference between an amount (or rate) of energy to be transferred according to the thermal energy transfer requirement and an amount (or rate) of energy transferred (or transferrable) in the operating mode.

[0185] 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. 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 in that operating mode.

[0186] 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.

[0187] The energy cost may, for example, be obtained from a lookup table, or by using a model of the thermal management system 100. 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 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.

[0188] 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.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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 104. This increase in retained thermal energy may reduce the amount of electrical 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. 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.

[0194] 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 100 may be maintained.

[0195] FIG. 6 illustrates a method 600 according to some examples. Thermal energy information is received at operation 602 and at operation 604 a first operating mode is selected as the current operating mode. At operation 606 it is determined whether the current operating mode is a candidate operating mode. If the operating mode is a candidate operating mode the method proceeds to operation 608, where it is determined whether the current operating mode satisfies one or more thermal energy transfer requirements. If the current operating mode is determined to satisfy the one or more thermal energy transfer requirements, the method proceeds to 610, where an energy cost for the current operating mode is determined. The method then proceeds to 612. The method also proceeds to 612 if it is determined at operation 606 that the current operating mode is not a candidate operating mode. Similarly, the method proceeds to 612 if is determined at operation 608 that the current operating mode does not satisfy the one or more thermal energy transfer requirements. At 612 it is determined whether there are any further operating modes. If there are further operating modes to consider the method proceeds to 614, where the next operating mode is selected as the current operating mode, and the method returns to operation 606. If, at 612, it is determined that all operating modes that are to be considered have been considered, the method proceeds to 616, where a recommended operating mode is selected. The recommended operating mode may be selected from among the operating modes for which an energy cost was determined. In some examples, the operating mode having the lowest cost may be selected as the recommended operating mode. In some examples, the recommended operating mode may be selected based on a cost function, where the cost function is based on the energy cost of the operating mode and possibly other factors.

[0196] In some examples, where no energy costs are determined, for example where none of the operating modes are determined at operation 608 to satisfy the one or more thermal energy transfer requirements, an operating mode may be selected at 616 based on the performance of the operating modes with respect to the one or more thermal energy transfer requirements. For example, an operating mode that best meets (e.g. comes closest to satisfying) the one or more thermal energy transfer requirements may be selected as the recommended operating mode.

[0197] According to the example of FIG. 6, determining whether the operating mode satisfies the one or more thermal energy transfer requirements may be avoided for operating modes that are not candidate operating modes. Similarly, the energy cost determination may be avoided for operating modes that do not satisfy the one or more thermal energy transfer requirements. This leads to an efficient selection of a recommended operating mode based on various considerations, such as a suitability of the operating mode and an energy cost associated with the operating mode.

[0198] In some examples, the determination of an energy cost associated with an operating mode may require more computing resource (on average) than determining whether the operating mode satisfies the one or more thermal energy transfer requirements. Similarly, determining whether the operating mode satisfies the one or more thermal energy transfer requirements may require more computing resource (on average) than determining whether an operating mode is a candidate operating mode. In such a case, the method 600 of FIG. 6 may be particularly efficient.

[0199] In alternative arrangements, an assessment of energy transfer rates / amounts may be carried out before determining candidate operating modes, such that rejected modes are determined before candidate operating modes, and the candidate operating modes are selected from modes that are not rejected. The selection of a recommended operating mode may then be performed, for example, on the basis of energy costs associated with the candidate operating modes. In other examples, a set of operating modes may be selected on the basis of energy costs of the operating modes and candidate operating modes selected from the set of operating modes. A recommended operating mode may then be selected from the candidate operating modes, e.g., based on energy transfer rates / amounts. In some examples, each stage may happen in turn. For example, in the method 600 of FIG. 6, a list of candidate operating modes may be determined, 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 complete 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. 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 (or may be immediately queued for performance), while other operating modes continue to be assessed with regard whether or not they are candidate operating modes. 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 determined immediately (or may be immediately queued for determination), while the assessment of other operating modes with regard to amount / rate of thermal energy transfer continues to be assessed.

[0200] 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 to absorb heat 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 determining candidate operating modes. However, other possibilities are also envisaged.

[0201] In some examples, the thermal energy transfer requirement for the respective component comprises a field that has one of a first, second or third value. The first value indicates that the component is below its target operating temperature range, the second value indicates that the component is above its target operating temperature range, and the third value indicates that the component is within its target operating temperature range. The values may be mutually exclusive, such that a component is associated with a no more than one of the values at any particular time.

[0202] The first value may be -1 , the second value may be +1 , and the third value may be 0. However, other values or symbols may be used. In some examples, the first value may be a negative number, the second value may be a positive number, and the third value may be 0 (here, 0 is considered to be unsigned, and neither positive nor negative, such that neither of the first or second values are zero). In some examples, the negative or positive number representing the first and second values may correspond with an amount of thermal energy to be transferred to or from the component, or a rate at which thermal energy is to be transferred to or from the component. In some examples, the number may indicate a temperature difference between the current temperature of the component and a target operating temperature (or target operating temperature range) of the component.

[0203] The first and second value may be considered indicative of a required, or obligatory transfer of thermal energy: the transfer is required in order to bring the component (e.g., a thermal customer) closer to its target operating temperature.

[0204] Where the component is designated as a thermal storage component, the third value may indicate that the component is usable as a source or sink of thermal energy. In this case, the third value may be considered indicative of an optional transfer of thermal energy. A transfer of thermal energy to or from the component is possible, but not required, for the component to be in its target operating temperature range. The third value would also be consistent with operating modes in which there is no transfer of thermal energy to or from the component.

[0205] Where the component is not designated as a thermal storage component, the third value may indicate that the component is not to transfer thermal energy to or from the thermal management system 100.

[0206] Whether the component is a thermal storage component may be a predetermined state that is fixed for the component, or may be included in the thermal energy information.

[0207] Accordingly, when the respective component is designated as a thermal storage component, the thermal energy transfer requirement for the respective component comprises: an indication that thermal energy is requested by the respective component; an indication that the respective component has excess thermal energy; an indication that the respective component is able to either receive or supply thermal energy. Each of these indications may be associated with a respective value of the field (e g., -1 . +1 , or 0).

[0208] When the respective component is designated as not a thermal storage component, the thermal energy transfer requirement for the respective component comprises: an indication that thermal energy is requested by the respective component; an indication that the respective component has excess thermal energy; or an indication that no thermal energy is to be transferred from or to the respective component. Each of these indications may be associated with a respective value of the field (e g., -1 . +1 , or 0).

[0209] Accordingly, it is possible to efficiently and intuitively indicate whether a component is (i) to act as a sink, (ii) to act as a source, (iii) available to act as either a sink or a source, or (iv) is available to act as neither a sink nor a source of thermal energy.

[0210] According to some examples, mode information for the operating modes may be obtained, the mode information comprising, for each operating mode, a thermal criterion for at least a first component of the plurality of components, the thermal criterion indicating whether the operating mode is compatible with the respective component being above, below, or within its target operating temperature range. The thermal criterion may be represented by a field of the mode information. The field may store one of first, second, or third states, respectively corresponding with the operating mode being compatible when the respective component is below, above, or within its target operating temperature range. The first, second and third states may be referred to as a high criterion, low criterion, and inrange criterion, respectively.

[0211] The first, second and third states may be mutually exclusive, such that for a given operating mode, a thermal criterion is associated with no more than one of the first, second and third states.

[0212] The high and low criteria may be numbers having opposite signs, and the in-range criterion may be zero. For example, the high and low criteria may be positive and negative, respectively. In some examples, the high and low criteria are “+1 ” and “-1 ”, respectively.

[0213] The thermal energy information may comprise, for at least a first component of the plurality of components, a thermal indicator indicative of whether the component is above, below, or within a target operating temperature range of the first component. The thermal indicator may be indicated by a field of the thermal energy transfer requirement, as described above. Determining whether the operating mode is a candidate operating mode may comprise comparing the mode information with the thermal indicator.

[0214] An operating mode may be a candidate operating mode if for each component of a set of components, the thermal criterion associated with that component in that mode matches the thermal indicator associated with that component. The set of components may be the set of thermal customers, for example, such that an operating mode is a candidate operating mode if, for each thermal customer, there is a match between the respective thermal indicator and the respective thermal criterion of that operating mode. In some examples, the set of components includes at least one thermal customer. In some examples, the set of components is a subset of the thermal customers. In some examples, each component of the set of components is a thermal customer.

[0215] There is a match between a thermal criterion and a thermal indicator if the thermal indicator indicates that the corresponding component has an excess of thermal energy and the thermal criterion indicates that, in the operating mode, the component acts as a source of thermal energy. Similarly, there is a match if the thermal indicator indicates that the corresponding component has a deficit of thermal energy and the thermal criterion indicates that, in the operating mode, the component acts as a sink of thermal energy.

[0216] In some examples, there is a match between a thermal criterion and a thermal indicator if the thermal indicator indicates that the component is below its target operating temperature range and the thermal criterion indicates that the corresponding operating mode is compatible with the respective component being below its target operating temperature range. Similarly, there is a match between a thermal criterion and a thermal indicator if the thermal indicator indicates that the component is above its target operating temperature range and the thermal criterion indicates that the corresponding operating mode is compatible with the respective component being above its target operating temperature range. Further, there is a match between a thermal criterion and a thermal indicator if the thermal indicator indicates that the component is within its target operating temperature range and the thermal criterion indicates that the corresponding operating mode is compatible with the respective component being within its target operating temperature range. In some examples, where the thermal indicator and thermal criterion have values of -1 , +1 , and 0, as described above, there may be a match between the thermal indicator and the thermal criterion if they have the same value. This may facilitate efficient determination of whether an operating mode is a candidate operating mode.

[0217] Other representations are possible for the thermal indicator and thermal criterion, and embodiments are not restricted to the particular examples herein.

[0218] 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 1 10) 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.

[0219] 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 thermal energy information (operation 502), determining (operation 504) whether operating modes of the thermal management system 100 are candidate operating modes, selecting (operation 506) a recommended operating mode from among the candidate operating modes, and providing an output (operation 508) indicating the recommended operating mode.

[0220] The device 700 may be included in controller 106 of an electric vehicle 200, as illustrated in FIG. 2, for example.

[0221] 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 . A method for controlling a thermal management system of an electric vehicle, the method comprising: obtaining thermal energy information for a plurality of components of the electric vehicle, the thermal energy information indicating a thermal energy transfer requirement for at least one respective component; determining, for each of one or more operating modes of the thermal management system, whether the operating mode is a candidate operating mode, wherein, in each candidate operating mode, the thermal management system is arranged to remove thermal energy from components that are indicated by the thermal energy transfer requirement as having excess thermal energy, and is arranged to provide thermal energy to components that are indicated by the thermal energy transfer requirement as requesting thermal energy; selecting a recommended operating mode from among the candidate operating modes, the recommended operating mode to be implemented in the thermal management system; and providing an output indicating the recommended operating mode.

2. The method of claim 1 , wherein selecting the recommended operating mode comprises evaluating each operating mode from among the candidate operating modes and selecting the recommended operating mode based on the evaluation.

3. The method of claim 2, wherein for one or more of the candidate operating modes the evaluation comprises at least one of: assessing a thermal energy transfer to an environment of the electric vehicle in the one or more candidate operating modes, assessing an energy cost associated with the one or more candidate operating modes, and assessing whether thermal energy transfers requested by components are achievable in the one or more candidate operating modes.

4. The method of claim 3, wherein the energy cost of an operating mode comprises at least one of a thermal energy cost value representing an amount of thermal energy transferred off the electric 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.

5. The method of any one of claims 1 to 4, wherein the thermal energy transfer requirement for a respective component comprises at least one of: an indication that thermal energy is requested by the respective component; an indication that the respective component has excess thermal energy; an indication that the respective component is able to either receive or supply thermal energy; or an indication that no thermal energy is to be transferred from or to the respective component.

6. The method of claim 5, wherein when the respective component is in a target operating temperature range associated with the respective component, the thermal energy transfer requirement comprises the indication that the respective component is able to either receive or supply thermal energy.

7. The method of claim 5, wherein when the respective component is in the associated target operating temperature range, the thermal energy transfer requirement comprises the indication that no thermal energy is to be transferred from or to the respective component.

8. The method of claim 5, wherein the thermal energy transfer requirement for the respective component comprises a field, the field has one of: a first value to indicate that thermal energy is requested by the respective component, a second value to indicate that the respective component has excess thermal energy, a third value to indicate, when the respective component is useable to store excess thermal energy, that the respective component is able to either receive or supply thermal energy, and the third value to indicate, when the respective component is not to be used to store excess thermal energy, that no thermal energy is to be transferred from or to the respective component.

9. The method of any one of claims 1 to 8, wherein each operating mode is associated with: a respective coolant configuration of a cooling system of the thermal management system, wherein each coolant configuration defines a direction of flow of thermal transfer fluid to at least one component of the cooling system; and a respective refrigerant configuration of a refrigerant system of the thermal management system, wherein each refrigerant configuration defines a direction of flow of thermal transfer fluid to at least one component of the refrigerant system.

10. The method of claim 9, wherein each operating mode is further associated with a respective state of a thermal link component of the thermal management system, the thermal link component being 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.11 . The method of any one of claims 1 to 10, comprising obtaining mode information for the operating modes, the mode information comprising, for each operating mode, a thermal criterion for at least a first component of the plurality of components, the thermal criterion indicating whether the operating mode is compatible with the first component being above, below, or within its target operating temperature range, wherein: the thermal energy information comprises, for at least the first component, a thermal indicator indicative of whether the component is above, below or within a target operating temperature range of the first component, and determining whether the operating mode is a candidate operating mode comprises comparing the mode information with the thermal indicator.

12. 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 the method of any one of claims 1 to 11 .

13. Computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform the method of any one of claims 1 to 11 .

14. A computer readable medium comprising computer readable instructions that, when executed by a processor, cause performance of the method of any one of claims 1 to 11 .

15. A vehicle comprising: the control system, of claim 12; and a thermal management system communicatively coupled to the control system.

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