Method and apparatus for predictive thermal management of an electric vehicle

Abstract

There is provided a method of determining an operating mode of a thermal management system of an electric vehicle. The method comprises obtaining route information indicative of a predicted route of the electric vehicle, predicting a future operating profile for the electric vehicle based on the route information, predicting, for at least one component of a plurality of components of the electric vehicle, a thermal energy transfer requirement for the component based on the future operating profile, selecting an operating mode of the thermal management system based on the predicted thermal energy transfer requirement for the at least one component, and outputting a signal indicative of the selected operating mode.

Description

[0001] METHOD AND APPARATUS FOR PREDICTIVE THERMAL MANAGEMENT OF AN ELECTRIC VEHICLE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a method and apparatus for determining an operating mode of a thermal management system of an electric vehicle. In particular, the present disclosure relates to a method and apparatus for selecting an operating mode from a plurality of operating modes for the thermal management system based on a predicted operating profile for the vehicle. Aspects of the invention relate to a method, a computer readable medium, computer readable instructions, a control system and 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, 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 desirable 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 leading to reduced 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 an method of determining an operating mode of a thermal management system of an electric vehicle, a computer program, a control system, and a vehicle as claimed in the appended claims.

[0010] According to an aspect of the present invention there is provided a method of determining an operating mode of a thermal management system of an electric vehicle, the method comprising predicting future thermal energy transfer requirements for components of the vehicle and selecting an operating mode based on the future thermal energy transfer requirements. Advantageously, by predicting future requirements, more efficient choices of operating mode may be achieved.

[0011] According to an aspect of the present invention there is provided a method of determining an operating mode of a thermal management system of an electric vehicle, the method comprising obtaining route information indicative of a predicted route of the electric vehicle, predicting a future operating profile for the electric vehicle based on the route information, predicting, for at least one component of a plurality of components of the electric vehicle, a thermal energy transfer requirement for the component based on the future operating profile, selecting an operating mode of the thermal management system based on the predicted thermal energy transfer requirement for the at least one component, and outputting a signal indicative of the selected operating mode.

[0012] Advantageously, the described method obtains information relating to a route that is predicted to be taken by the vehicle and uses that information to predict how the vehicle will be operated, for example highway driving, or approaching congested traffic. Having determined a prediction of how the vehicle will be operated, the thermal energy transfer requirement for components of the vehicle for that operating profile can be predicted, and the predicted thermal energy transfer requirements used to select an operating mode of the thermal energy system to meet the predicted requirements that will be experienced over the expected route to be taken by the vehicle. For example, the operating mode that is expected to be the most efficient for the predicted conditions, i.e. lowest energy cost for the evaluated operating modes, may be selected which may lead to improved overall efficiency for the electric vehicle.

[0013] Optionally, predicting the thermal energy transfer requirement for the component comprises predicting the thermal energy transfer requirement over a predetermined period of time. Uncertainties in a predicted route and also in predicted thermal energy transfer requirements for components may be less certain for times further into the future. Advantageously, the prediction may be performed for a predetermined time period which may be chosen to provide a suitable confidence in the predicted values.

[0014] Optionally, the thermal energy transfer requirement for a component comprises one of: an indication that thermal energy is to be supplied to the component; an indication that thermal energy is to be extracted from the component; or an indication that thermal energy may be supplied to or extracted from the component.

[0015] Advantageously, the thermal energy requirement may be signalled as a request for cooling / heating or an indication that the component is within a tolerable band of temperatures and is therefore able to act as either a source or sink of thermal energy while remaining within the desired range. This information may allow a decision to be made to store thermal energy in a component for later use. In some embodiments, the thermal energy transfer requirement may be an amount of energy, or energy flux, to be transferred to or extract from the component to maintain the component within a desired temperature range. An operating mode may be said to satisfy the thermal energy transfer requirement for a component when it is able to transfer to or extract from that component at least the amount of energy, or energy flux, indicated by the thermal energy transfer requirement.

[0016] Optionally, the thermal energy transfer requirement for a component comprises one of: an amount of thermal energy to be supplied to the component; an amount of thermal energy to be extracted from the component; or an indication that thermal energy may be supplied to or extracted from the component.

[0017] Advantageously, the thermal energy requirement may signal an amount of energy to be supplied or extracted from a component to allow a calculation of an energy balance for the system when determining an operating mode to implement thermal transfers between the components.

[0018] In an embodiment, obtaining the route information comprises receiving the route information from a satellite navigation apparatus.

[0019] Advantageously, route information may be obtained from a satellite navigation apparatus used by a driver of the vehicle to provide routing information to a programmed destination. This may increase confidence in the expected route of the vehicle.

[0020] In an embodiment, obtaining the route information comprises determining a road characteristic for a road being driven by the vehicle, the method further comprising predicting the future operating profile based on the road characteristic.

[0021] Advantageously, route information may be obtained by determining a characteristic of a current road being used and providing predictions based on that characteristic, that is that the road conditions / profile can be expected to be similar to the current road conditions, allowing predictions to be made based on current conditions when accurate information on an intended route is not available.

[0022] In an embodiment, obtaining the route information comprises obtaining an indication of traffic conditions, the method further comprising predicting the future operating profile based on the traffic conditions.

[0023] Advantageously, route information may include traffic conditions, e.g. an indication of congestion ahead on the road, and the future operating profile can be predicted taking into account the traffic conditions. Thus, an operating mode may be selected taking into account upcoming traffic conditions.

[0024] In an embodiment, the method comprises obtaining a model of thermal energy generation during operation of the component for each of the one or more components, and wherein predicting the thermal energy transfer requirement for the component comprises calculating an amount of thermal energy generated based on the expected operating profile using the model.

[0025] Advantageously, generation of thermal energy by each individual component may be modelled for expected conditions and the model used to predict an amount of thermal energy that will be generated by the component while the vehicle follows the predicted route. The predicted thermal energy transfer requirement may then be more accurately determined based on the expected amount of thermal energy generated. In an embodiment, the component comprises an electric drive unit, and predicting the thermal energy transfer requirement for the electric drive unit comprises determining an expected power output from the electric drive unit based on the route information, and calculating a thermal energy value indicative of an amount of thermal energy that will be generated in the electric drive unit based on the expected power output.

[0026] Advantageously, the method may be applied to an electric drive unit to predict an amount of thermal energy that will be generated by the electric drive unit while the vehicle follows the route based on how much motive power is expected to be provided by the drive unit. For example, the route information may be used to predict a vehicle speed, elevation gains, periods of acceleration, etc., that can be used to determine an expected power output while following the predicted route. This expected power output may then be used to more accurately determine the amount of thermal energy that will be generated in the electric drive unit.

[0027] In an embodiment, the component comprises a fraction battery, and predicting the thermal energy transfer requirement for the traction battery comprises predicting a current to be supplied by the battery based on the route information, and calculating a thermal energy value indicative of an amount of thermal energy that will be generated in the traction battery based on the predicted current.

[0028] Advantageously, the method may be applied to a fraction battery to predict an amount of thermal energy that will be generated by the fraction battery while the vehicle follows the route based on how much current is drawn from the battery. For example, the route information may be used to predict a vehicle speed, elevation gains, periods of acceleration, etc. that can be used to determine an expected current supplied by the fraction battery while following the predicted route. This expected current may then be used to more accurately determine the amount of thermal energy generated in the battery.

[0029] In an embodiment, the method further comprises obtaining thermal energy information for the one or more components of the vehicle, the thermal energy information indicating a current state of the component, and wherein predicting the thermal energy transfer requirement for the component is further based on the thermal energy information.

[0030] Advantageously, a current thermal, or temperature, state of the components of the vehicle, for example whether a traction battery is currently within its desired operating temperature range, can be taken into account when predicting the thermal energy transfer requirement for the component so as to select an operating mode that obtains or maintains the desired operating temperature for the components while taking into account predicted operation of the component.

[0031] According to another aspect of the invention, there is provided computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform a method as disclosed herein.

[0032] Optionally, the computer readable instructions may be stored on a computer readable medium.

[0033] According to a further aspect of the invention, there is provided a control system for controlling a thermal management system of a vehicle, the control system comprising one or more processors collectively configured to obtain route information indicative of a predicted route of the vehicle, predict a future operating profile for the electric vehicle based on the route information, predict, for at least one component of a plurality of components of the electric vehicle, a thermal energy transfer requirement for the component based on the expected future operating profile, select an operating mode of the thermal management system based on the predicted thermal energy transfer requirement for each component, and output a signal indicative of the selected operating mode.

[0034] Advantageously, the control system obtains information relating to a route that is predicted to be taken by the vehicle and uses that information to predict how the vehicle will be operated, for example highway driving, or approaching congested traffic. Having determined a prediction of how the vehicle will be operated, the thermal energy transfer requirement for components of the vehicle for that operating profile can be predicted, and the predicted thermal energy transfer requirements used to select an operating mode of the thermal energy system to meet the predicted requirements that will be experienced over the expected route to be taken by the vehicle. For example, the operating mode that is expected to be the most efficient for the predicted conditions, i.e. lowest energy cost for the evaluated operating modes, may be selected which may lead to improved overall efficiency for the electric vehicle. According to an embodiment, the control system for controlling a thermal management system comprises one or more controllers collectively comprising at least one electronic processor having an electrical input for receiving an input signal; and at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to perform any of the methods as described herein.

[0035] In an embodiment, the one or more processors are collectively configured to predict the thermal energy transfer requirement for the component by predicting the thermal energy transfer requirement over a predetermined period of time.

[0036] Optionally, the thermal energy transfer requirement for a component comprises one of an amount of thermal energy to be supplied to the component, an amount of thermal energy to be extracted from the component, or an indication that thermal energy may be supplied to or extracted from the component.

[0037] In an embodiment, the one or more processors are further collectively configured to obtain a model of thermal energy generation during operation of the component for each of the one or more components, and wherein predicting the thermal energy transfer requirement for the component comprises calculating an amount of thermal energy generated based on the expected operating profile using the model.

[0038] In an embodiment, the component comprises an electric drive unit, and the one or more processors are further collectively configured to predict the thermal energy transfer requirement for the electric drive unit by determining an expected torque output from the electric drive unit based on the route information, and calculating a thermal energy value indicative of an amount of thermal energy that will be generated in the electric drive unit based on the expected torque output.

[0039] In an embodiment, the component comprises a fraction battery, and the one or more processors are further collectively configured to predict the thermal energy transfer requirement for the fraction battery by predicting a current to be supplied by the battery based on the route information, and calculating a thermal energy value indicative of an amount of thermal energy that will be generated in the fraction battery based on the predicted current.

[0040] According to an aspect of the present invention there is provided a vehicle comprising a control system as described herein.

[0041] 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.

[0042] BRIEF DESCRIPTION OF THE DRAWINGS

[0043] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0044] Figure 1 shows a system suitable for implementing embodiments of the invention;

[0045] Figure 2 illustrates a vehicle including the system of Figure 1 and suitable for implementing embodiments of the invention;

[0046] Figure 3 illustrates a schematic representation of a powertrain thermal management system suitable for implementing embodiments of the invention;

[0047] Figure 4 illustrates a method of selecting an operating mode of a vehicle thermal management system according to embodiments of the invention;

[0048] Figure 5 illustrates another method of selecting an operating mode of a vehicle thermal management system according to embodiments of the invention; and

[0049] Figure 6 illustrates a control system suitable for performing the method of Figure 4 or 5. DETAILED DESCRIPTION

[0050] According to embodiments of the invention, a control system may select an operating mode of a thermal management system to meet predicted thermal transfer requirements of one or more components of an electric vehicle, such as a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV). By obtaining route information that indicates an expected, or predicted, route that the vehicle will travel, it is possible to predict the expected demands placed on the component of the vehicle when navigating the predicted route. These demands may include an estimated power to be delivered by a traction battery or a torque or power to be supplied by one or more traction motors of the vehicle. Thermal energy transfer requirements for the one or more components may thus be based on the predicted demands of navigating the route.

[0051] The control system may use the predicted thermal energy transfer requirements for the components to estimate energy cost values associated with respective operating modes of the thermal management system to meet those predicted thermal energy transfer requirements.

[0052] Based on the predicted energy cost values, an operating mode associated with a lowest determined energy cost can be identified. The identified operating mode may then be provided as an output signal indicating an operating mode of the thermal management system to meet the predicted thermal energy demands of the components of the electric vehicle.

[0053] By taking a whole system energy based approach for multiple components of the vehicle while meeting the predicted thermal requirements of those components, the amount of thermal energy retained on the vehicle for use by other systems and components may be maximised, or at least substantially increased, compared to temperature based approaches, for example by avoiding rejecting to an external environment heat generated in a traction battery during operation that could usefully be transferred to another system such as a climate control system. This increase in retained thermal energy may reduce the amount of energy that would otherwise be drawn from the traction battery to provide heat energy for those other systems, increasing efficiency with which energy is used on the electric vehicle, resulting in increased range and a corresponding improved user experience.

[0054] With reference to Figure 1 , there is illustrated a vehicle thermal management system 100 for an electric vehicle in accordance with an embodiment of the present invention. The vehicle thermal management system 100 includes at least one controller 106 that is communicatively coupled to a powertrain thermal management system (PTM) 102 and a climate control system (CCS) 104 that comprises a heating, ventilation and air conditioning (HVAC) system, to receive state information and / or sensor readings from one or more components of the PTM 102 and HVAC, e.g. coolant or refrigerant temperature and mass flow rate measurements.

[0055] In embodiments, the controller 106 may be communicatively coupled to one or more components of the electric vehicle, for example via a (Controller Area Network (CAN) bus or similar network present on the vehicle 200, and is operable to obtain thermal energy information from the components. The thermal energy information defines a thermal energy transfer requirement for each of the components of the electric vehicle. The controller 106 is further arranged to provide indications of a selected operating mode to the PTM 102 and CCS 104 to influence the operation of those sub-systems.

[0056] The vehicle thermal management system 100 as illustrated in Figure 1 comprises one controller 106, although it will be appreciated that this is merely illustrative. The controller 106 comprises processing means 108 and memory means 110. The processing means 108 may be one or more electronic processing device 108 which operably executes computer-readable instructions. The memory means 110 may be one or more memory device 110. The memory means 110 is electrically coupled to the processing means 108. The memory means 110 is configured to store instructions, and the processing means 108 is configured to access the memory means 110 and execute the instructions stored thereon.

[0057] In Figure 2, controller 106, PTM 102, and CCS 104 are provided in electric vehicle 200, such as an automobile. A powertrain of the vehicle 200 comprises at least one electric drive unit 202a / b and a traction battery 204. The or each electric drive unit 202a / b comprises one or more electric fraction motors for propelling the vehicle 200. The fraction battery 204 is a high voltage (HV) battery and is configured to supply electrical current to the at least one drive unit 202a / b. In the present embodiment, the vehicle 200 comprises a front electric drive unit 202a for driving the front wheels of the vehicle 200; and a rear electric drive unit 202b for driving the rear wheels of the vehicle 200. In use, the front and rear electric drive units 202a, 202b are both powered by the fraction battery 204. Each electric drive unit 202a / b 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 Figure 1 , the PTM 102 is coupled to the CCS 104 of the cabin of the vehicle which is able to control a temperature of the vehicle cabin for occupant comfort.

[0058] While the traction battery 204, electric drive units 202a / b and HVAC may be the most significant generators and / or users of thermal energy supplied by the PTM 102, it will be recognized that other vehicle components may be coupled to the PTM 102 and may have thermal requirements to be met by the PTM. For example, in embodiments, the 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, in embodiments, the electrical vehicle 200 may be provided with computer processing hardware that requires active cooling.

[0059] The components of the vehicle may have a target operating temperature range or respective ranges, and operating the components outside of that range may lead to increased power consumption of the component or for the vehicle 200 as a whole. For example, when the temperature of the fraction battery 204 increases, internal resistive losses within the fraction battery 204 may also be expected to increase, while chemical reactions in the fraction battery 204 may be inhibited when cold, similarly leading to increased losses in the battery. Such losses, when the powertrain components are not maintained within the desired operating temperature range, will result in reduced range for the vehicle 200.

[0060] The vehicle thermal management system 100 is operable as a supply or sink of thermal energy to components of the vehicle 200, and in particular PTM 102 is thermally coupled to the fraction battery 204 and electric drive units 202a / b and able to extract or supply thermal energy to these components to satisfy thermal energy transfer requirements of these components.

[0061] In an illustrative example of operation of the vehicle, thermal energy may be supplied via the PTM 102 to the fraction battery 204 and electric drive units when beginning operation of the vehicle 200 from cold to more quickly bring the components to the desired operating temperature range. During further operation of the vehicle 200, heat may be generated in the fraction battery 204 and electric drive units 202a / b, for example due to internal resistance of the cells of the fraction battery 204. To maintain the temperature of the powertrain components within the desired temperature range, heat generated in the powertrain components of the vehicle 200 may be extracted by the thermal management system 102. The extracted thermal energy may be transferred between components of the vehicle 200, for example thermal energy extracted from the battery 204 may be supplied to CCS 104 for use in heating the cabin of the vehicle 200, or may be transferred off the vehicle 200, for example via a low temperature radiator to transfer the thermal energy to the outside environment.

[0062] The vehicle 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 an operating mode having a lowest, or at least reduced, energy cost for operation of the vehicle thermal management system 100 to meet the current thermal energy transfer requirements of the vehicle 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.

[0063] Furthermore, selecting an operating mode based only on a current state of the vehicle component may not allow changes in the generation of heat in the vehicle to be taken into account. For example, for an electric vehicle 200 being driven on a clear highway, the power supplied by the battery may be relatively high, leading to significant heat generation within the traction battery 204 due to internal resistance. At the same time, significant airflow may be expected over a low temperature radiator of the vehicle. An operating mode for the vehicle thermal management system 100 may be selected to extract heat generated within the traction battery 204 and reject that heat through the low temperature radiator to the environment, while providing a portion of the heat energy to the CCS 104 for cabin heating . The electric vehicle 200 may then slow, for example due to congestion on the highway or leaving the highway for a local road, resulting in reduced heat generation in the traction battery 102 which may now be insufficient for cabin heating. In order to maintain a comfortable temperature for the cabin occupants, thermal energy may be supplied from another source, such as a heater drawing power from the traction battery 204, which undesirably uses power drawn from the fraction battery.

[0064] According to embodiments of the invention, route information indicating a predicted route of the vehicle may be received and analysed to determine a predicted operating profile for the vehicle 200. In the case of the above example, it may be recognized that the vehicle 200 will be required to slow in the near future, for example due to congestion or a change in road conditions, and the predicted thermal transfer requirements for the fraction battery can be calculated based on this change in operating profile. Based on the predicted thermal transfer requirements, a different operating mode may be selected for the vehicle thermal management system 100 that retains more thermal energy on the vehicle 200, for example by temporarily allowing the temperature of the traction battery 204 and electric drive units 202a / b to rise rather than rejecting the heat to the outside environment. The retained thermal energy may then be supplied to CCS 104 for cabin heating once the electric vehicle slows, reducing electrical power drawn from the fraction battery 204 for cabin heating.

[0065] A schematic representation of an example PTM 102 is shown in Figure 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 units 202a, the rear electric drive unit 202b, the battery unit 204 and the climate control system, or climate control unit 104 of the vehicle cabin for occupant comfort. The PTM 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 vehicle 200. The coolant heater 304 may be a high voltage (HV) heater that draws electrical power directly from fraction battery 204.

[0066] The first heat exchanger 306 may be configured selectively to cool the coolant of the PTM 102. A refrigerant circuit of the CCS 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 CCS 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 CCS 104 to the coolant of the PTM 102, for example to allow for the supply heat sourced from the outside environment via an outside heat exchanger of the CCS 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.

[0067] The control valve apparatus 302 comprises a first pump 310 and a second pump 312. The PTM 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 and second coolant circulation loops 314, 316 to perform supply or sinking of thermal energy to the front and rear electric drive units 202a, 202b and the fraction 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.

[0068] 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 fraction 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 and second coolant circulation loops 314, 316 may be selectively connected to each other to enable the supply of coolant from the first heat exchanger 304 to the front and rear electric drive units 202a / b.

[0069] 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 fraction 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 unit 204.

[0070] The second coolant circulation loop 316 is configured to supply coolant to the front and rear electric drive units 202a / b. The second heat exchanger 308 is provided in the second coolant circulation loop 316 downstream of the front and rear electric drive units 202a / b. 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. 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.

[0071] 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 102. When the first heat exchanger 306 is active, it couples the coolant circuit it is in with the refrigerant circuit.

[0072] Herein coupling between the first coolant circulation loop 314, second coolant circulation loop 316 and / or 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.

[0073] Thus, control valve apparatus 302 allows the configuration of the thermal management system 102 to be controlled to selectively bypass certain components of the thermal management system, such as the second heat exchanger 308, and / or to selectively couple the first and second coolant circulation loops 314, 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 configurations of the PTM 102. For each configuration, one or more components may be controlled to different states, for example first heat exchanger 306 may be on or off depending on whether refrigerant is provided to the first heat exchanger 306, second heat exchanger 308 may be selectively bypassed, etc. As such, there may be multiple operating modes of the PTM 102 for each of the configurations of the PTM , resulting in a large total number of possible operating modes for the PTM 102 from which an operating mode is to be selected by the controller 106 to meet current requirements of the various components of the electric vehicle 200.

[0074] In embodiments, CCS 104 may include a refrigerant circuit including a compressor, at least one internal evaporator operable to extract heat energy from air in the cabin, at least one internal condenser operable to supply heat 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 PTM 102 and the refrigerant of the HVAC . Thus, CCS 104 may be operable in multiple modes. In some embodiments, selection of an operating mode for the CCS 104 may be coordinated with a selected operating mode for PTM 102 to further improve overall efficiency of the vehicle thermal management system 100.

[0075] 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 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 and / or CCS 104 are examples of thermal customers.

[0076] Figure 4 illustrates a method 400 of determining an operating mode of a thermal management system, such as the vehicle thermal management system 100, of an electric vehicle 200 that can be performed by the controller 106 illustrated in Figure 1 . According to the illustrated method 400, route information indicative of a predicted route of the vehicle 200 can be obtained 402. For example, route information may be obtained from a satellite navigation system or infotainment system of the vehicle 200, or other source. Route information may be explicitly set by a user of a vehicle, for example a user may set a destination and a corresponding route determined. In some embodiments, route information may be determined implicitly, for example a vehicle travelling on a highway may be implicitly determined to be expected to continue along the highway until at least a next junction. Route information may include a road characteristic, such as type of road, traffic data indicating a level of traffic, congestion, etc. that may be experienced along a predicted route. Furthermore, route information may include gradient or elevation data.

[0077] Based on the route information, a future operating profile for the electric vehicle 200 may be predicted at block 404. The future operating profile may include indications of predicted velocities of the vehicle, whether the vehicle may be expected to brake for a junction, changes in elevation, etc. relating to operation of the vehicle while traversing the predicted route. This information is then used to predict 406 for at least one component of the electric vehicle 200 a predicted thermal energy transfer requirement for that component while the vehicle traverses the route. This may be based on a predictive model of the component that can be used to predict an amount of thermal energy, or rate of heat energy, generated in a component according to the expected future operating profile of the vehicle.

[0078] For example, the future operating profile may be used to predict an amount and / or rate of electrical energy (i.e. electrical power) to be supplied from the traction battery 204 while the vehicle traverses the predicted route with an expected speed profile, allowing for elevation changes, etc. A predictive model of the traction battery 204 can then be used to predict the heat energy that will be generated in the fraction battery 204 to supply the required electrical energy, and a thermal transfer requirement for the traction battery 204 indicating an amount of thermal energy to be transferred to or from the battery 204 to maintain the fraction battery 204 within a target temperature range determined. Similarly, heat generation in other components, such as electric drive units 202a / b, may be predicted based on the expected future operating profile, such as predicted power output, and corresponding predicted thermal energy transfer requirements for those components determined.

[0079] In block 408 an operating mode for the vehicle thermal management system 100, for example an operating mode of the PTM 102 and / or CCS 104, can be selected based on the predicted thermal energy transfer requirement for the at least one component. The selected operating mode may be selected from a plurality of operating modes that are operable to meet the predicted thermal energy transfer requirements of one or more components of the electric vehicle. In some embodiments, an energy cost associated with each the plurality of operating modes may be determined and an operating mode having a lowest respective energy cost selected. A signal indicative of the selected operating mode is then output, e.g. by controller 106 to PTM 102 and / or CCS 104. The method then outputs 410 a signal indicating the selected operating mode.

[0080] The predicted thermal energy transfer requirement for a component may indicate that thermal energy is to be supplied to the component or extracted from the component. The thermal energy information may indicate an amount of thermal energy, for example a number of Joules, to be transferred to or from that component to change its temperature to a desired operating range. In some embodiments, the thermal energy transfer requirement may indicate a rate, or flux, of thermal energy to be transferred to / from the component. In embodiments, the thermal energy transfer requirement may be determined based on a temperature difference between a current temperature of the component and a desired temperature range combined with a heat capacity of the component. The heat capacity of the component may be determined empirically or calculated based on a specific heat capacity of the material of the component and a mass. In the case that the temperature of the component is already within the desired temperature range, the thermal energy information may provide an indication that thermal energy may be transferred to or extracted from the component. For example, a component, such as the fraction battery 204, that is predicted to be within a target temperature range may be used as a source of thermal energy that may be transferred by the vehicle thermal management system 100 to another component e.g. to avoid use of the heater for as long as the traction battery 204 is able to supply heat energy while remaining within the desired temperature range.

[0081] In embodiments, the method may further include obtaining current thermal energy information for the one or more components defining a current state of the component, e.g. a current temperature or thermal energy transfer requirement of the component. The current thermal energy information may be combined with the future operating profile of the vehicle to determine the predicted thermal energy requirement, e.g. in the case that the traction battery 204 is current operating below an associated target temperature range, the predicted thermal energy transfer requirement for the traction battery may be determined to allow an amount of heat energy expected based on the future operating profile to be generated in the traction battery to be retained to cause the temperature of the battery to rise to the target temperature range.

[0082] Figure 5 illustrates a method 500 of selecting an operating mode of the thermal management system based on a predicted thermal energy transfer requirement of at least one component of a plurality of components of an electric vehicle 200. According to the illustrated method 500, thermal energy information for a plurality of components of the electric vehicle 200 is obtained 502, the thermal energy information defining a thermal energy transfer requirement for each component. For at least some of the components, the obtained thermal energy information comprises a predicted thermal energy transfer requirement as described above.

[0083] Information defining a plurality of operating modes of the vehicle thermal management system 100 is obtained in block 504. The plurality of operating modes defined by the obtained information may be a subset of the total number of operating modes of the vehicle thermal management system 100 that are able to satisfy the thermal energy transfer requirements, including predicted thermal energy transfer requirements, of each component. For example, if the predicted thermal energy information indicates that the traction battery 204 is expected to generate a certain amount of thermal energy that should transferred away from the battery to avoid exceeding a target operating temperature range, only those operating modes capable of extracting heat energy from the fraction battery 204 may be defined in the information obtained in block 504. For each operating mode of the operating modes defined in block 504, an energy cost value may be determined 506 for operating the thermal energy system 100 in that operating mode. The energy cost value may represent an actuator energy cost associated with the operation of the PTM 102 and CCS 104, and also an amount of thermal energy to be transferred off the electric vehicle 200. The energy cost for each operating mode may be determined using a predictive model of the vehicle thermal management system 100 and / or of the PTM 102 and CCS 104.

[0084] Heat energy may be transferred off the vehicle via the second heat exchanger 308, or low temperature radiator, or by transferring heat to the refrigerant circuit of the CCS 104 via the first heat exchanger 306 and then to the outside environment via an outside heat exchanger of the refrigerant circuit. The total amount of heat transferred off the electric vehicle 200 using the vehicle thermal management system 100 is determined to calculate the thermal energy transferred off the vehicle.

[0085] The actuator energy cost may include any energy associated with operating the vehicle thermal management system 100, for example an energy cost required to operate the compressor of the refrigerant circuit 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 PTM 102 and CCS 104, 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.

[0086] As discussed above, the energy cost for each operating mode may be determined using a predictive model of the vehicle thermal management system 100. In embodiments, the predictive model of the thermal management system may comprise a plurality of predictive models each associated with a respective sub-component of the thermal management system. 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 vehicle thermal management system and an energy cost associated with the actuator. For example, a predictive model for the compressor of the refrigerant circuit may allow an energy cost of operating the compressor to be determined based on certain operating parameters, such as a duty cycle of the compressor. Each model may be determined empirically or through simulation of the thermal management system 102 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.

[0087] Similarly, predictive models may be provided for the first and second heat exchangers and for an outer heat exchanger of the refrigerant circuit 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.

[0088] 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 vehicle 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. Based on the calculated energy costs for each of the plurality of operating modes, the operating mode having the lowest calculated energy cost is selected at block 508. An output including an indication of the selected operating mode is then provided as discussed above.

[0089] Thus, the method 500 is able to identify which of the operating modes of the vehicle thermal management system 100 is able to most efficiently meet the predicted thermal transfer requirements of the components of the electric vehicle 200, leading to an increase in the achievable range from the charge available in the fraction battery 204.

[0090] In embodiments, the thermal energy transfer requirement may be predicted for a certain period of time, for example a predefined number of minutes. The energy cost associated with each operating mode may be calculated for the same period of time, allowing for dynamic effects such as predicted changes in the operating regime of the vehicle (e.g. highway driving; around town; parked) to be taken into accountwhen selecting a lowest energy cost operating mode for the thermal management system.

[0091] In embodiments, an indication of a target temperature associated with a temperature sensor of the PTM 102 may be obtained and the energy cost associated with each operating mode may be further based on the target temperature. The temperature sensor may measure a temperature of the heat transfer fluid, such as the coolant, flowing in a coolant circulation loop, or may be arranged to measure a temperature of one of the components thermally coupled to the PTM 102. Each operating mode may have an associated target temperature value used to determined energy costs values for that operating mode.

[0092] Certain methods and systems as described herein may be implemented by one or more processors that process program code that is retrieved from a non-fransitory storage medium. Figure 6 shows an example 600 of a device comprising a computer-readable storage medium 620 coupled to at least one processor 610. The computer-readable media 620 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 media 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.

[0093] In Figure 6, the computer-readable storage medium comprises program code to perform a method corresponding to the embodiment shown in Figure 4, that is: obtaining 402 route information indicative of a predicted route of the vehicle; predicting 404 a future operating profile of the electric vehicle based on the route information; predicting 406 a thermal energy transfer requirement or at least one component of the electric vehicle based on the future operating profile; selecting 408 an operating mode for the vehicle thermal management system based on the predicted thermal energy transfer requirement; and outputting 410 a signal indicating the selected operating mode.

[0094] In embodiments, the computer-readable storage medium may comprise program code to perform a method corresponding to the embodiment of Figure 5.

[0095] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

CLAIMS1 . A method of determining an operating mode of a thermal management system of an electric vehicle, the method comprising: obtaining route information indicative of a predicted route of the electric vehicle; predicting a future operating profile for the electric vehicle based on the route information; predicting, for at least one component of a plurality of components of the electric vehicle, a thermal energy transfer requirement for the component based on the future operating profile; selecting an operating mode of the thermal management system based on the predicted thermal energy transfer requirement for the at least one component; and outputting a signal indicative of the selected operating mode.

2. The method of claim 1 , wherein predicting the thermal energy transfer requirement for the component comprises predicting the thermal energy transfer requirement over a predetermined period of time.

3. The method of claim 1 or claim 2, wherein the thermal energy transfer requirement for a component comprises one of: an amount of thermal energy to be supplied to the component; an amount of thermal energy to be extracted from the component; or an indication that thermal energy may be supplied to or extracted from the component.

4. The method of any preceding claim, the method further comprising: obtaining a model of thermal energy generation during operation of the component for each of the one or more components; and wherein predicting the thermal energy transfer requirement for the component comprises calculating an amount of thermal energy generated based on the expected operating profile using the model.

5. The method of any preceding claim, wherein the component comprises an electric drive unit, and wherein predicting the thermal energy transfer requirement for the electric drive unit comprises: determining an expected power output from the electric drive unit based on the route information; and calculating a thermal energy value indicative of an amount of thermal energy that will be generated in the electric drive unit based on the expected power output.

6. The method of any preceding claim, wherein the component comprises a traction battery, and wherein predicting the thermal energy transfer requirement for the traction battery comprises: predicting a current to be supplied by the battery based on the route information; and calculating a thermal energy value indicative of an amount of thermal energy that will be generated in the traction battery based on the predicted current.

7. The method of any preceding claim, the method further comprising: obtaining thermal energy information for the one or more components of the vehicle, the thermal energy information indicating a current state of the component; and wherein predicting the thermal energy transfer requirement for the component is further based on the thermal energy information.

8. Computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform the method according to any of claims 1 to 7.

9. 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 route information indicative of a predicted route of the electric vehicle;predict a future operating profile for the electric vehicle based on the route information; predict, for at least one component of a plurality of components of the electric vehicle, a thermal energy transfer requirement for the component based on the expected future operating profile; select an operating mode of the thermal management system based on the predicted thermal energy transfer requirement for each component; and output a signal indicative of the selected operating mode.

10. The control system of claim 9, wherein the one or more processors are collectively configured to predict the thermal energy transfer requirement for the component by predicting the thermal energy transfer requirement over a predetermined period of time.

11. The control system of claim 9 or claim 10, wherein the thermal energy transfer requirement for a component comprises one of: an amount of thermal energy to be supplied to the component; an amount of thermal energy to be extracted from the component; or an indication that thermal energy may be supplied to or extracted from the component.

12. The control system of any of claims 9 to 11 , wherein the one or more processors are further collectively configured to: obtain a model of thermal energy generation during operation of the component for each of the one or more components; and wherein predicting the thermal energy transfer requirement for the component comprises calculating an amount of thermal energy generated based on the expected operating profile using the model.

13. The control system of any of claims 9 to 12 , wherein the component comprises an electric drive unit, and the one or more processors are further collectively configured to predict the thermal energy transfer requirement for the electric drive unit by: determining an expected power output from the electric drive unit based on the route information; and calculating a thermal energy value indicative of an amount of thermal energy that will be generated in the electric drive unit based on the expected power output.

14. The control system of any of claims 9 to 13, wherein the component comprises a traction battery, and the one or more processors are further collectively configured to predict the thermal energy transfer requirement for the traction battery by: predicting a current to be supplied by the battery based on the route information; and calculating a thermal energy value indicative of an amount of thermal energy that will be generated in the traction battery based on the predicted current.

15. A vehicle comprising the control system of any of claims 9 to 14.

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