A method for the heating with improved energy efficiency of a high-voltage battery of an electric powertrain of a vehicle

Abstract

There is described a method by means of which it is possible to improve the energy efficiency of a vehicle with an electric powertrain, by recovering the thermal power rejected by one or more traction components (TRC) and using it for heating a high-voltage battery (BATT), which in turn reduces the internal electrical resistance and increases the efficiency of the same battery. This enables reducing the energy consumption for cooling the at least one traction component (TRC), since the thermal capacity of the battery (BATT) is used for the absorption of the thermal power rejected by the at least one traction component, i.e. the flow rate of heat transfer liquid returning to the at least one traction component has temperature conditions which favour cooling the at least one traction component, without resorting to the use of a cooling radiator on the branch R1. Ultimately, said improvement of the energy efficiency increases the driving range of the vehicle.

Description

[0001] "A method for the heating with improved energy efficiency of a high-voltage battery of an electric powertrain of a vehicle"

[0002] ★★★★

[0003] TEXT OF THE DESCRIPTION

[0004] Field of the Invention

[0005] The present invention relates to the thermal conditioning, specifically to the heating, of a high- voltage battery of an electric powertrain of a vehicle (specifically of a BEV). The invention was developed with particular reference to a cooling circuit with a heat transfer liquid, which operates in a heat exchange relationship with the high-voltage battery and with one or more traction components of the vehicle, and to the possibility of improving the energy efficiency thereof.

[0006] Prior Art

[0007] The vehicles with an electric powertrain, especially BEVs, need a thermal conditioning system of the traction components and a thermal conditioning system of a high-voltage battery which supplies one or more electric motors of the powertrain, in addition to the traditional thermal conditioning system of the passenger compartment. The phrase "traction components" generally denotes each electric traction motor of the vehicle, and in case the corresponding transmission which connects the motor to the one or more drive wheels operationally connected thereto.

[0008] As regards the cooling of the traction components, this is operated by means of a heat exchange between a heat transfer liquid, circulating in a circuit which is in a heat exchange relationship with the same traction components, and which includes a radiator for dissipating the heat transferred from the traction components to the heat transfer liquid.

[0009] The functions of cooling and heating the passenger compartment are operated respectively by means of an interaction with a refrigeration cycle cooling circuit, traversed by a refrigerant fluid which undergoes phase changes from liquid to gas and from gas to liquid (for cooling), and by means of a direct heat exchange between the heat transfer liquid and the passenger compartment (for heating). The cooling of the high-voltage battery which supplies the one or more electric traction motors is generally operated by means of the same refrigeration cycle cooling circuit dedicated to cooling the passenger compartment, particularly by means of one or more chillers, i.e. evaporation devices being in a heat exchange relationship with a cooling circuit with a liquid which impinges upon the high-voltage battery. The heating of the high-voltage battery is generally operated by means of an electric heater, which heats the heat transfer liquid of the thermal conditioning circuit of the battery, and which is the same heat transfer liquid being in a heat exchange relationship with the one or more evaporation devices of the corresponding chillers. The heating of the high-voltage battery is operated, with reference to Figures 1 and 2, essentially for energy efficiency reasons: the diagram in Figure 1 shows a qualitative evolution of an internal resistance ^Batjnt °f the high-voltage battery as a function of a battery temperature TBat, whereas Figure 2 shows a qualitative evolution of an efficiency EBatof the high- voltage battery as a function of the battery temperature TBat. It is easy to notice that the internal resistance RBat_int °f the battery decreases as the temperature TBatincreases, with a consequent increase of the efficiency thanks to the reduction of Joule losses EBatdue to the reduction of the internal resistance.

[0010] However, in a vehicle with an electric powertrain, the consumption of electric power for heating the high- voltage battery is not negligible. Generally speaking, the consumption of electric power may lead to a reduction of the maximum electric discharge power of the high- voltage battery in some operating conditions of the battery and of the vehicle.

[0011] Therefore, the general need is felt to reduce, as much as possible and when possible, the consumption of electric power by the high-voltage battery, particularly as regards the heating of the high-voltage battery. In other words, notwithstanding the fact that the high- voltage battery anyway requires a heating device, the need is felt of finding an energy-efficient alternative to the electric heater for supplying the thermal heating power, since the heater draws electric power from the high-voltage battery.

[0012] Object of the Invention

[0013] The invention aims at solving the technical problem described in the foregoing. Specifically, the object of the invention is to limit the electric power consumption for the heating of the high-voltage battery, in particular by means of an energy-efficient alternative with respect to the electric heater which heats the heat transfer liquid of the thermal conditioning circuit of the battery by drawing power from the same battery.

[0014] Summary of the Invention

[0015] The object of the invention is achieved by means of a method having the features set forth in the claims that follow, which form an integral part of the technical disclosure provided herein in relation to the invention.

[0016] Brief Description of the Figures

[0017] The invention will now be described with reference to the annexed Figures, which are provided by way of non-limiting example only and wherein:

[0018] - Figure 1 shows a qualitative evolution of an internal resistance RBatjnt ofahigh-voltage battery as a function of a battery temperature TBat, and Figure 2 shows a qualitative evolution of an efficiency EBatof the high-voltage battery as a function of the battery temperature TBat,

[0019] Figure 3 schematically shows a thermal conditioning circuit whereon it is possible to implement a method according to the invention,

[0020] - Figure 4 shows a block diagram exemplifying the method according to the invention,

[0021] Figures 5 to 15 show diagrams exemplifying operations or steps of the method according to the invention.

[0022] Detailed Description

[0023] Reference C in Figure 1 generally denotes a thermal conditioning circuit, specifically a combined circuit for the thermal conditioning of a high-voltage battery of a vehicle with an electric powertrain, and of one or more traction components of the electric powertrain of the vehicle, which is used as an example for describing the implementation of the method according to the invention.

[0024] The circuit C comprises: at least one traction component TRC of the powertrain traversed by a first flow rate of heat transfer liquid mTrcin a first flow direction Fl, wherein the at least one traction component includes - alternatively or in combination, depending on whether they undergo interactions with the flow rate mTrc- an electric traction motor, an inverter operationally connected to the electric traction motor, a transmission which connects an electric traction motor with one or more corresponding drive wheels of the vehicle, thereby meaning that the components under consideration comprise a cooling jacket within which the heat transfer liquid of the circuit C flows, or else they comprise an operating fluid - for example an oil for the transmission - which is in a heat exchange relationship with the flow rate mTrcby means of a heat exchanger which is traversed, in a heat exchange relationship (only), by the flow rate mTrcor by a fraction thereof, as a function of the branches of the circuit and of the flow rate of operating fluid;

[0025] - a first circulation pump TP having a delivery port arranged upstream of the at least one traction component TRC with respect of the first flow direction Fl of the heat transfer liquid. The first circulation pump TP supplies the first flow rate mTrcto the at least one traction component TRC;

[0026] - a first recirculation branch R1 which connects an outlet of the at least one traction component TRC with a suction port of the first circulation pump TP. The recirculation branch R1 is traversed by a first recirculation flow rate mR1; a heat exchange device CHL, specifically a chiller, traversed by a second flow rate 'rhBatof heat transfer liquid in a second flow direction F2, wherein the heat exchange device includes a thermal conditioning circuit BTC (schematically represented as a coil with dashed-line contours) of a battery BATT of the powertrain, specifically a high-voltage battery configured to supply one or more electric traction motors of the powertrain of the vehicle, wherein the thermal conditioning circuit BTC is traversed by the flow rate mBat°f heat transfer liquid, and moreover includes an evaporation device supplied with refrigerant fluid and being in operational relationship with, in particular being part of, a refrigeration cycle circuit wherein said refrigerant fluid flows, wherein the evaporation device is in a heat exchange relationship with the thermal conditioning circuit BTC. The refrigerant fluid traversing the evaporation device of the chiller CHL (flow rates mRFRCHLIN, inlet, and mRFRCHL0UT, outlet), circulates thanks to the action of an electrically operated compressor (which is not shown as it is known per se);

[0027] - a second circulation pump BP having a delivery port arranged upstream of the heat exchange device CHL with respect to the second flow direction F2 of said heat transfer liquid. The second circulation pump BP supplies the second flow rate mBatto the heat exchange device CHL, thus to the thermal conditioning circuit BTC,

[0028] - a second recirculation branch R2 which connects an output of the thermal conditioning circuit BTC with a suction port of the second circulation pump BP, the second recirculation branch being traversed by a second recirculation flow rate mR2,

[0029] - a first branch Bl configured for a transit of a spill flow rate from the first recirculation branch R1 towards the second recirculation branch R2, specifically towards the suction port of the second circulation pump BP,

[0030] - a second branch B2 configured for a transit of the spill flow rate from the second recirculation branch R2 to the first recirculation branch Rl, wherein a spill valve VI is arranged upstream of the second branch B2 to regulate the transit of the spill flow rate fiispjit from the second recirculation branch R2 to the first recirculation branch Rl (the phrase "regulate the transit of the spill flow rate ThSpnt" indicates that the valve VI is configured to deliver a flow rate of an amount which varies continuously - by varying the throttling degree of the same valve - between a zero flow rate and a maximum flow rate admitted by the valve VI, which may be equal to 'rhBat). As a general premise, every reference to a "flow rate" in the present description must be construed with reference to a mass flow rate, as attested by the choice of the notation m for all flow rates.

[0031] Always referring to Figure 3, the recirculation branch R1 and the recirculation branch R2 substantially define a return path for the heat transfer liquid towards the suction of the pumps TP and BP, respectively. Moreover, it is possible to notice, in the circuit C, the presence of some circuit nodes, denoted by the references Nl, N2, N3. The circuit node N1 is arranged at the intersection of the first recirculation branch R1 with the branch Bl, and upstream of the circuit node N2 along the branch Rl, wherein the node N2 is in turn arranged upstream of the suction of the pump TP. Between the nodes Nl and N2 there extends a fraction of the recirculation branch Rl denoted by the reference RIA, which is located downstream of the branch Bl.

[0032] The branch Bl extends from the node Nl to the node N3, which is arranged upstream of the suction port of the pump BP. The arrangement "upstream" is herein defined with respect to the only flow direction admissible in the branch Bl, which goes from the node Nl towards the suction of the pump BP, thus towards the node N3. The flow direction is not necessarily dictated by the presence of a one-way valve along the branch Bl itself between the nodes Nl and N3 (the presence whereof is not excluded), but it is dictated by the flow directions Fl, F2 and by the components in the vicinity of the node Nl and the node N3.

[0033] The node N2 is arranged upstream of the suction of the pump TP and downstream of the valve VI. The valve VI is preferably a three-port, continuous-positioning valve, comprising a first port Vl / 1, a second port Vl / 2 and a third port Vl / 3, wherein the ports Vl / 1 and Vl / 2 are always in fluid communication with each other (with the exception of the instance wherein the flow rate is equal to the flow rate hiBatracase which may possibly enable excluding the mutual fluid communication whereof) in order to allow for the recirculation of the flow rate mBat towards the suction of the pump BP, whereas the port Vl / 3 is in fluid communication with the ports Vl / 1 and Vl / 2 in a variable amount (including the absence of fluid communication) dependent on the amount of the spill flow rate to be delivered towards the node N3 and the recirculation branch R1.

[0034] The second branch B2 extends from the valve VI - specifically, from the port Vl / 3 - to the node N2. The arrangements "upstream" and "downstream" are defined by the unique function of the suction port of the pump TP (which admits one flow direction only) and by the need to return the spill flow rate from the branch R2 (which extends from an outlet of the circuit BTC to the suction port of the pump BP, passing through the valve VI, ports Vl / 1 and Vl / 2. Between the port Vl / 2 and the node N3 a fraction of the recirculation branch R2 extends which is denoted by the reference R2A, which is located downstream of the same valve VI.

[0035] As can be observed in the circuit diagram of Figure 1, the flow rate m^p^ is spilled from the flow rate mTrcaccording to a fashion described in the following, and is sent to the suction of the pump BP directly through the branch Bl. Since the flow rate is required for the cooling of the at least one traction component, it must return to the suction of the pump TP, and this is achieved through the branch R2 and the valve VI. The flow rate recirculating in the branch RIA is therefore equal to the flow rate (which is generally equal to mTrc) minus the flow rate ihspiitr the latter flow rate being reintegrated at the node N2. The circuit C moreover includes a plurality of temperature sensors, which comprise:

[0036] - a first temperature sensor TS_A, configured to detect a temperature TRadInof the heat transfer liquid coming from (i.e. leaving) the at least one traction component TRC,

[0037] - a second temperature sensor TS_B, configured to detect a temperature TBatctntInof the heat transfer liquid entering the circuit BTC, and

[0038] - a third temperature sensor TS_C, configured to detect a temperature TBatCintOutof the heat transfer liquid leaving the circuit BTC.

[0039] This being said, the invention defines a method for managing a thermal conditioning circuit C of a vehicle with an electric powertrain which enables determining - and, in the affirmative case, implementing - whether the conditions exist for heating the battery BATT by supplying to the circuit BTC a flow rate of heat transfer liquid coming from the at least one traction component TRC, moreover achieving the effect of cooling the at least one traction component TRC by means of the heat transfer liquid coming from (i.e., leaving) the same circuit BTC downstream of the battery heating, thus a heat transfer liquid having a temperature TBat ctnt Out< TBat_cint_inr without using a radiator for cooling the at least one traction component TRC.

[0040] According to the invention, and with reference to the Figures 4, 5, the method includes enabling (Bat_Trc_Cnct_En = 1), via the spill valve VI, a transit of spill flow rate of heat transfer liquid from an outlet of the thermal conditioning circuit (BCT) of the battery (BATT) through the second branch (B2) to a suction of the first circulation pump (TP) if each (block 2A, "AND") of the following conditions is met:

[0041] - a thermal power rejected by the at least one traction component TRC is not used by one or more receiving users having higher priority for the use of the rejected thermal power (block 2, Figure 4 and letter

[0042] A, Trc_Heat_Rej_HP_Act = 0, Figure 5), in particular for energy efficiency purposes,

[0043] - the thermal power rejected by the at least one traction component TRC is not reserved for one or more receiving users having higher priority for the use of the rejected thermal power (block 2, Figure 4 and letter

[0044] B, Trc_Heat_Rej_HP_Res = 0, Figure 5), in particular for energy efficiency purposes,

[0045] - the possibility exists (block 2, Figure 4 and letter C, Trc_Heat_Rej_Bat_Usbl = 1, Figure 5) of transferring said thermal power rejected by the at least one traction component TRC to the battery BATT,

[0046] - a critical temperature of the battery BATT has not been reached (block 2, Figure 4 and letter D, Crit_Bat_Temp = 0, Figure 5),

[0047] - it is not expected to incur the need for battery cooling during a corresponding mission of the vehicle (E, No_Bat_Clg_Exp = 1)

[0048] - there are no faults (block 2, Figure 4 and letter F, No_Comp_Fault = 1, Figure 5) in the thermal conditioning circuit (C).

[0049] If the determination has a positive outcome, i.e. the transit of the spill flow rate is enabled, the method further includes determining (block 4, Figure 4) a target value ThSputTgt of the spill flow rate ThSpiit, and operating a heating of the battery BATT by means of a flow rate of heat transfer liquid coming from the at least one traction component (thus coming from the outlet of the at least one traction component) by enabling, by means of the spill valve VI, a transit of the spill flow rate 'rhSpntTgt from the outlet of the thermal conditioning circuit BTC of the battery BATT through the second branch R2 to a suction of the first circulation pump TP.

[0050] In preferred embodiments of the method, verifying the conditions as per letters A and B depends on the determinations operated in control methods being external to the extent of the invention, but being a part of the general thermal management of the vehicle and of the powertrain of the vehicle. In more detail, the circumstance which corresponds to the condition as per letter A is represented by a state variable Trc_Heat_Rej_HP_Act, which acquires the logic state "0" (FALSE) when the condition A is met, thus when the thermal power rejected by the at least one traction component TRC is not used by one or more receiving users having higher priority for the use of the rejected thermal power (in the diagram of Figure 5, this is represented by a block N corresponding to a logical negation operator - NOT - upstream of the input of the variable Trc_Heat_Rej_HP_Act into the block AND 2A), and the logic state "1" (TRUE) when the condition A is not met, thus when the thermal power rejected by the at least one traction component TRC is used by one or more receiving users having higher priority for the use of the rejected thermal power.

[0051] The circumstance corresponding to the condition as per letter B is represented by a state variable Trc_Heat_Rej_HP_Res, which acquires the logic state "0" (FALSE) when the condition B is met, i.e. when the thermal power rejected by the at least one traction component TRC is not reserved for one or more receiving users having higher priority for the use of the rejected thermal power (in the diagram of Figure 5, this is represented by a block N corresponding to a logical negation operator - NOT - upstream of the input of the variable Trc_Heat_Rej_HP_Res in the block AND 2A), and the logic state "1" (TRUE) when the condition B is not met, i.e. when the thermal power rejected by the at least one traction component TRC is reserved for one or more receiving users having higher priority for the use of the rejected thermal power. It is a further condition with respect to the condition A: the latter is the expression of an actual use of the thermal power rejected from the at least one traction component by one or more receiving users having higher priority of use, whereas the condition B is the expression of a reserve (thus of a lack of current use) of the thermal power rejected by the at least one traction component in favour of one or more receiving users having higher priority of use.

[0052] With reference to the Figures 6 to 15, there will now be described the determinations operated in the method according to the invention with respect to the verifications C, D, E, F.

[0053] With reference to Figure 6, the diagram 10 is a functional representation of a diagram for deducing the possibility of transferring the thermal power rejected by the at least one traction component to the battery BATT, specifically to the thermal conditioning circuit BTC of the battery BATT.

[0054] The possibility of transferring the thermal power rejected by the at least one traction component to the battery BATT, specifically to the thermal conditioning circuit BTC of the battery BATT, is associated with a variable Trc_Heat_Rej_Bat_Usbl, which acquires the logic state "0" (FALSE) when there is no possibility of transferring the thermal power rejected by the at least one traction component to the battery BATT, and the logic state "1" (TRUE) when there is a possibility of transferring the thermal power rejected by the at least one traction component to the battery BATT. The diagram 10 illustrates, in this regard, the procedure for determining the logic state of the variable Trc_Heat_Rej_Bat_Usbl, i.e. the fashion for ascertaining the presence or the absence of such a possibility.

[0055] The input data item for determining the logic state of the variable Trc_Heat_Rej_Bat_Usbl is a difference (block 12) between a temperature TTrcCintOutof the heat transfer liquid leaving the at least one traction component TRC (i.e. the temperature of the hottest point of the circuit of heat transfer liquid dedicated to the at least one traction component) and a temperature TBat ctnt Outof the heat transfer liquid leaving the thermal conditioning circuit BTC of the battery BATT (i.e., the temperature of the coldest point of the circuit of heat transfer liquid dedicated to the battery BATT). The difference 12 is processed by means of an anti-hysteresis logic represented by a set-reset flip-flop block 14 having an output Q, a set input S and a reset input R. The output Q corresponds to the state Trc_Heat_Rej_Bat_Usbl = 1 (TRUE) when the condition associated to the input S is met, whereas it corresponds to the condition Trc_Heat_Rej_Bat_Usbl = 0 when the condition associated with the input R is met.

[0056] The condition associated with the input S corresponds to a physical condition wherein the difference TTrc clnt Out- TBat clnt Outis greater than, specifically greater than or equal to (block 16) a first threshold value ^TTrcHeatUsbt Hi, whereas the condition associated with the input R corresponds to a physical condition wherein the difference TTrc Cint Out- TBat Cint Outis less than, specifically less than or equal to (block 18), a second threshold value TTrcHeatUsbi Lo.

[0057] This means, from a physical point of view, that as soon as the temperature of the heat transfer liquid in the hottest point of the circuit of heat transfer liquid dedicated to the at least one traction component is higher (by an amount equal to the value ^TTrcHeatUsbt Hi) than the temperature of the coldest point of the circuit of heat transfer liquid dedicated to the battery BATT, it is possible to transfer the thermal power from the one (TRC) to the other (BTC) circuit.

[0058] Therefore, in the method according to the invention, condition C, there is the possibility (Trc_Heat_Rej_Bat_Usbl = 1) of transferring the thermal power rejected by the at least one traction component TRC to the battery BATT when the difference TTrcCintOut— TBat_cint_out is greater than, specifically greater than or equal to, the first threshold value ^TTrcHeatUsbt Hi, and there is no possibility (Trc_Heat_Rej_Bat_Usbl = 0) of transferring the thermal power rejected by the at least one traction component TRC to the battery BATT when the difference TTrc clnt Out- TBat clnt Outis less than, specifically less than or equal to, the second threshold value TTrcHeatUsbi Lo. The first and the second threshold values are selected in such a way as to avoid toggling events between the two states of the variable Trc_Heat_Rej_Bat_Usbl and to avoid thermal power leakages.

[0059] Referring to Figure 7, diagram 20, it represents, from a functional point of view, a diagram for deducing the achievement of the critical temperature of the battery BATT.

[0060] The event of reaching the critical temperature of the battery BATT is associated with a variable Crit_Bat_Temp which acquires the logic state "0" (FALSE) when the critical temperature of the battery BATT is not reached, and the logic state "1" (TRUE) when the critical temperature of the battery BATT is reached. The diagram 20 shows, in this regard, the procedure for determining the logic state of the variable Crit_Bat_Temp, i.e. the procedure for ascertaining the achievement of the critical temperature of the battery BATT.

[0061] The input data item for determining the logic state of the variable Crit_Bat_Temp is a value of maximum cell temperature TBat_ceii_Max of the battery BATT, which corresponds to a limit operational value to avoid fire events of the battery BATT.

[0062] The maximum cell temperature TBat_ceii_Max is processed by means of an anti-hysteresis logic represented by a set-reset flip-flop block 22 having an output Q, a set input S and a reset input R. The output Q corresponds to the state Crit_Bat_Temp = 1 (TRUE) when the condition associated with the input S is met, whereas it corresponds to the condition Crit_Bat_Temp = 0 when the condition associated with the input R is met.

[0063] The condition associated with the input S corresponds to a physical condition wherein the maximum cell temperature TBat CeU Maxis greater than, specifically greater than or equal to (block 24), a third threshold value TBat CenLim Hi, whereas the condition associated with the input R corresponds to a physical condition wherein the maximum cell temperature TBat CeU Maxis less than, specifically less than or equal to (block 26), a fourth threshold value TBat CeU Lim Lo. Generally speaking, TBat_ceii_Lim_Hi> TBa[Beniimi0holds true.

[0064] The third and the fourth threshold values are chosen in such a way as to avoid toggling events between the two states of the variable Crit_Bat_Temp.

[0065] In the method according to the invention, the critical temperature of the battery (Crit_Bat_Temp = 1) is considered as reached when the maximum cell temperature TBat_ceii_Max of the battery is greater than, specifically greater than or equal to, TBat CeuLimHi, and the critical temperature of the battery is considered as not reached (D, Crit_Bat_Temp = 0) when the maximum cell temperature CTBat_ceii_Max') of the battery BATT is less than, specifically less than or equal to, TBca CeU LimLo.

[0066] With reference to Figure 8, diagram 30, it shows, from the functional point of view, a diagram for deducing the need to cool the battery BATT during a corresponding mission of the vehicle.

[0067] The prediction of the need to cool the battery BATT during a mission of the vehicle is associated with a variable No_Bat_Clg_Exp, which acquires the logic state "0" (FALSE) when there is the need to cool the battery BATT during a corresponding mission of the vehicle, and the logic state "1" (TRUE) when there is no need to cool the battery BATT during a corresponding mission of the vehicle. The purpose of verifying said condition (E) is the following: if it is expected that during the mission of the vehicle a condition will be incurred of needing a cooling of the battery BATT (No_Bat_Clg_Exp = 0), it is useless to recover the thermal power rejected by the at least one traction component for the heating the same battery BATT, since the energy consumption for the following cooling is greater than the energy saving obtained by recovering the thermal power rejected by the at least one traction component TRC.

[0068] The diagram 30 shows, in this regard, the procedure for determining the logic state of the variable No_Bat_Clg_Exp, i.e. the procedure for ascertaining the prediction of incurring (or not incurring) the need to cool the battery BATT.

[0069] The input data item for determining the logic state of the variable No_Bat_Clg_Exp is a difference TBat Befcig (block 32) between a target value TBat CeuMaXTgt °f the maximum cell temperature of the battery BATT and a predicted cell temperature value of the battery at the end of the mission TBatCenEndMission.

[0070] The difference 32, i.e. the value ETstBefcig / is processed by means of an anti-hysteresis logic represented by a set-reset flip-flop block 34 having an output Q, a set input S and a reset input R. The output Q corresponds to the state No_Bat_Clg_Exp = 1 (TRUE) when the condition associated with the input S is met, whereas it corresponds to the state No_Bat_Clg_Exp = 0 when the condition associated with the input R is met.

[0071] The condition associated with the input S corresponds to a physical condition wherein the residual temperature difference ETBat Befcig(at the end of the mission) before the intervention of the battery cooling BATT is greater than, specifically greater than or equal to (block 36) a fifth threshold value &TBat CeuHi, whereas the condition associated with the input R corresponds to a physical condition wherein the residual temperature difference ATBat Befagis less than, specifically less than or equal to (block 38), a sixth threshold value ^TBatCell_Lo•

[0072] Therefore, in the method according to the invention, condition E, it is not expected to incur the need to cool the battery during a corresponding mission of the vehicle (No_Bat_Clg_Exp = 1) when the difference &TBat_BefCig is greater than, specifically greater than or equal to, the fifth threshold value &TBat CeuHi, and it is expected to incur the need to cool the battery BATT during a corresponding mission of the vehicle (No_Bat_Clg_Exp = 0) when the difference &TBat Befcigis less than, specifically less than or equal to, the sixth threshold value &TBatCeuLo. The fifth and the sixth threshold values are selected in such a way as to avoid toggling events between the two states of the variable No_Bat_Clg_Exp , and in such a way as to maintain a safety margin with respect to the intervention of a cooling of the battery BATT.

[0073] Always referring to Figure 8, the value of the cell temperature of the battery BATT predicted at the end of the mission TBat CenEndMissioncomprises a sum (block 39) of the maximum cell temperature TBat CeU Maxand of a predicted temperature increase ATBat Incrdependent on the mission of the vehicle.

[0074] The following Figure 9, diagram 40, shows a functional diagram representative of the determination of the predicted temperature increase ATBat lncr. The predicted temperature increase ATBat Incrdependent on the mission of the vehicle is calculated (block 41) as a ratio CQBatTotX End Mission) / h.rm Bat / wherein:

[0075] - QBat_Tot isatotal thermal power generated by the battery BATT,

[0076] - AtEnd Missionis a time remaining before the end of the mission (specifically the corresponding mission, with respect to which the method according to the invention is implemented). From an operational point of view, the time AtEnd Missionmay be extracted from the navigation data (if the driver has set a destination on the on-board navigator) or else by means of predictive algorithms based on learning the driving habits, or else by means of predictive algorithms based on a combination of learning the driving habits from the previous missions and learning in real time based on the current driving conditions .

[0077] - CThrm Batis a thermal capacity of the battery BATT.

[0078] The total thermal power QBat_Tot generated by the battery BATT is calculated as a difference (block 42) between a thermal power QBat_Hrj rejected by the battery BATT and a thermal power QBatAmb_Exg transferred by the battery BATT to the external environment, as a function of a temperature difference ATBatAmbbetween the battery BATT and the external environment. On an operational level, the value QsatAmbExg is extracted from a map 43 which uses, as input data item, the temperature difference ATBatAmb.

[0079] In turn, the temperature difference ATBatAmbbetween the battery BATT and the external environment is calculated as a difference (block 44) between an average cell temperature value TBat Ceii_MidMission of the battery BATT and a temperature of the external environment TAmb. The average cell temperature value TBat Ceii_MidMission is calculated (block 45) as a ratio

[0080] CellMaxTgt~ ATBadcell_Hi+ ^Batt_CeW_Max) / 2r wherein

[0081] TsaitceilMaxTgt is the maximum cell temperature target value of the battery BATT, &TBat CeiiHiis the fifth threshold value, TBatt CeuMaxis the current maximum cell temperature of the battery (BATT). The numerator of the ratio which defines the value TBat Ceii_MidMission is determined by mathematical operators at the blocks 46 and 47, wherein the block 46 determines the difference TBatt Ceii_Max_Tgt~ ^TBatceilHI and the block 47 determines the sum of the difference TBatt CeiiMax Tgt- &TBat Cell Hiand of the value TBatt_ceii_Max• The denominator of the ratio defining the value TBat CeuMidMissionis determined by a block 48 which provides the value "2" input into the block 45.

[0082] Physically, the temperature TBat Ceii_MidMission corresponds to an arithmetic average between the current value TBattceilMax and the value of the end of the mission TBatt_Cell_Max_Tgt~ &TBatceii_Hi' which in turn corresponds to the maximum cell temperature target value reduced by the safety margin &TBat CeiiHI which, as stated in the foregoing, also represents a safety margin, in addition to a threshold value for the operation of the flip-flop block 34.

[0083] Figure 10, diagram 50, functionally represents a diagram for deducing the absence of faults as per condition F, in this case with particular reference to the preferred embodiment shown in the Figures. The absence of faults in the thermal conditioning circuit C is associated with a variable No_Comp_Fault, which acquires the logic state "0" (FALSE) when there is (at least) a failure in the circuit C, and the logic state "1" (TRUE) when there is no fault in the circuit C, specifically no fault in the components which are monitored in order to define the condition F itself. The diagram 50 shows, in this regard, the procedure for determining the logic state of the variable No_Comp_Fault, i.e. the procedure for ascertaining the presence or the absence of a fault in the circuit C.

[0084] In the preferred embodiment shown in the Figures, according to the method there are no faults (F, No_Comp_Fault = 1) in the thermal conditioning circuit (C) if an absence of faults (No_Fault) is ascertained for each (block 51, AND) of said spill valve VI (block 52, Three_Ways_Valve_Status = No_Fault'), first temperature sensor TS_A (block 53, Coolant_Temperature_Sensor_A_Status = No_Fault), second temperature sensor TS_B (block 54, Coolant_Temperature_Sensor_B_Status = No_Fault'), third temperature sensor TS_C (block 55,

[0085] Coolant_Temperature_Sensor_C_Status = No_Fault'), second circulation pump BP (block 56, Battery_Pump_Status = No_Fault), and first circulation pump TP (block 57, Traction_Pump_Status = No_Fault'), whereas there are faults if at least one of the conditions as per blocks 52- 57 is not met, which leads to switching the logical state of the variable No_Comp_Fault from 1 to 0 based on the truth table of the block 51 (AND). Generally speaking, the invention focuses on the detection of faults in components used for defining and calculating the spill flow rate rii-spiit and in the components used for (physically) obtaining the spill flow rate rii-spiit•

[0086] The following Figures 11 to 15 show the calculation steps performed for determining the target value 'rhspiitTgt of the spill flow rate mSpiit.

[0087] Figure 11, diagram 60, functionally represents a diagram for calculating a maximum spill flow rate value ThsputMaxi i.e. an upper limit for the flow rate mSpiit. The value riiSputMax is the output data item of a switch SW60 which is controlled by the logic state of the variable Bat_Trc_Cnct_En, determined by the operator AND as per block 2A, and corresponding to the value "1" (TRUE) when all conditions A-F are met, and to the value "0" (FALSE) when at least one of the conditions A-F is not met. The variable Bat_Trc_Cnct_En expresses enabling (or not enabling) the transit of the spill flow rate riispiitr i-e. enabling the hydraulic connection between the circuit dedicated to the at least one traction component TRC and the circuit dedicated to the thermal conditioning of the battery BATT.

[0088] This being said, in the condition shown in Figure 11, corresponding to the case wherein Bat_Trc_Cnct_En = 1, the value riiSpiit Maxis equal to the lower (block 62, MIN) out of a target value of the first flow rate mTrcTgtand a target value of the second flow rate riiBatTgt, both coming from control methods external to the extent of the invention. In the opposite case, i.e. in the absence of the enablement of the transit of the spill flow rate mspiit (Bat_Trc_Cnct_En = 0), the value 'rhspiitMax is equal to the zero value (block 64).

[0089] Figure 12, diagram 70, functionally represents a diagram for determining the target value 'rhspiitTgt of the spill flow rate ThSpiit. The target value Thspitt_Tgt is determined as the lower (block 71, MIN) out of the value rhspiitMax and the greater (block 74, MAX) out of a sum (block 76) of a target value of spill flow rate determined by means of an open-loop calculation mSpiit 0L Tgtand a target value of spill flow rate determined by means of a closed loop calculation mSpiit CL Tgtand the zero value (block 78). In other words, the target value ThSpiit Tgtis determined as a sum of the values riT-spiitOLTgt and ThsputcL_Tgti being limited superiorly (block 71) to the value ThSpiit Maxand inferiorly to the zero value (block 74), so as to prevent the flow rate riispiit from having negative values corresponding to an inadmissible inversion of the flow direction thereof.

[0090] The flow rate rii-spiitTgt has the function of recovering as much thermal power as possible, while at the same time respecting a maximum admissible temperature value of the heat transfer liquid entering the circuit BTC ^BatClntInTgt•

[0091] Referring to Figure 13, diagram 80, a target temperature value TBat ctnt In Tgtof the heat transfer liquid entering the thermal conditioning circuit of the battery BATT is therefore determined as a difference (block 82) between a maximum admissible temperature value of the heat transfer liquid entering the circuit BTC TBat ctnt In Max(determined by means of a method external to the extent of the invention) and a temperature interval &TBat ctnt Maxwhich defines a safety margin with respect to the maximum value.

[0092] The following Figure 14, diagram 90, shows the steps for determining the target value of the spill flow rate determined by means of an open-loop calculation ThSpiitoL_Tgt• In more detail, the calculation of the value mSpiit_OLTgt comprises: i) determining a raw target value of spill flow rate by means of an open-loop calculation ThSpiit 0L Raw Tgt, . ,,i . ™BatTgtx[TBatClntInTat~TBatClntOut) as a ratio (block 91) - - ,

[0093] V Trc_Clnt_Out ^BatClntOut) wherein:

[0094] TTrccintout is the temperature value of the heat transfer liquid leaving the at least one traction component (TRC), read by the sensor TS_A,

[0095] TBat_cint_in_Tgt isatarget value for the temperature of the heat transfer liquid entering the thermal conditioning circuit BTC of the battery BATT,

[0096] TBat_cint_out is the temperature value of the heat transfer liquid leaving the thermal conditioning circuit BTC of the battery BATT, read by the sensor TS_C, riiBat_Tgt is a target value of the second flow rate of the heat transfer liquid mBat.

[0097] The numerator of the ratio defining the value riispiitoL_Tgt is determined by mathematical operators at the blocks 92 and 93, wherein the block 93 calculates the difference TBat clnt In Tgt- TTrccintout and the block 92 multiplies mBatTgtby the difference TBat ctnt In Tgt- TTrc_cint_out output by the block 93. The denominator of the ratio defining the value rii-spiLtOLTgt is determined by a subtraction operator of a block 94; ii) determining a saturated value of the spill flow rate by means of an open loop calculation mSpiit 0L Sat Tgtas the lower (block 95, MIN) out of the maximum value of the spill flow rate mSpiit Maxand the greater (block 96, MA) out of the raw target value of the spill flow rate determined by means of an open-loop calculation ^spiit_OL_Raw_Tgt and the zero value (block 98); iii) adopting the saturated value of the spill flow rate by means of an open-loop calculation mSpiit 0L Sat Tgtas the target value of the spill flow rate determined by an open-loop calculation mSpiit 0L Tgtif a transit of the spill flow rate irtspiit is enabled (Bat_Trc_Cnct_En = 1): this corresponds to the condition shown in Figure 14 and represented by a switch SW90 which uses the variable Bat_Trc_Cnct_En as a control variable. Indeed, the case shown in Figure 14 corresponds to the condition Bat_Trc_Cnct_En = 1; iv) adopting the zero value (block 99) as the target value of the spill flow rate determined by an open-loop calculation mSpiit 0L Tgtif a transit of the spill flow rate msplit is not enabled (Bat_Trc_Cnct_En = 0): it is the opposite case with respect to the case shown in Figure 14.

[0098] Finally, Figure 15, diagram 100, schematically shows the determination of the target value of the spill flow rate determined by means of a closed-loop calculation mSpiitCLTgt. Such a determination comprises: i) calculating the target value of the spill flow rate determined by a closed-loop calculation mSpiit CL Tgtby means of a proportional-integral controller 101 as a function of a difference (block 102) TBat clnt ln Tgt-TBat clnt lnbetween the target value TBat ctnt In Tgtof the temperature of the heat transfer liquid entering the thermal conditioning circuit BTC of the battery BATT and a current value TBatctntInof the temperature of the heat transfer liquid entering the thermal conditioning circuit BTC of the battery BATT (read by the sensor TS_B) if a transit of a spill flow rate rii-spiit is enabled 'Bat_Trc_Cnct_En = 1), wherein the proportional-integral controller 101 includes an upper saturation limit 103 and a lower saturation limit 104. The upper saturation limit corresponds to a difference (block 105) riiSpiitMax— thsputOLTgt between the maximum spill flow rate value ThsputMax and the target spill flow rate value determined by an open-loop calculation Thspitt_OL_Tgt (thus it corresponds to the residual margin available for the closed-loop calculation, considering the intervention of the open-loop calculation), whereas the lower saturation limit 104 corresponds to the opposite —riiSpiit0LTgtof the target spill flow rate value determined by an open-loop calculation mSpiit 0L Tgt(in this way, the result of the combination of the values mSpUt0LTgt+ mSpiitCLTgtfi.e. the result downstream of the closed-loop correction, may be at the limit equal to 0, without acquiring negative values). What is being described corresponds to the condition shown in Figure 15 and represented by a switch SW90, which uses the variable Bat_Trc_Cnct_En as a control variable. The case shown in Figure 14, indeed, corresponds to the condition Bat_Trc_Cnct_En = 1; - adopting the zero value (block 106) as the target value of the spill flow rate determined by a closed-loop calculation mSpiit CL Tgtif a transit of the spill flow rate spiit is not enabled (Bat_Trc_Cnct_En = 0). What is being described corresponds to the condition opposite to the case shown in Figure 15, wherein the condition Bat_Trc_Cnct_En = 0 holds true.

[0099] Moreover, when the condition Bat_Trc_Cnct_En = 0 is met, the result of the closed-loop calculation of the proportional-integral controller 101 is reset: in Figure 15, this is represented by a block 108 of logical negation of the condition Bat_Trc_Cnct_En = 1 (thus Bat_Trc_Cnct_En = 0), which corresponds to a reset input 109 of the controller 101.

[0100] It is easy to observe that the determinations illustrated in Figures 11, 14, 15 (and, indirectly, the determinations as per Figures 12, 13) all depend on the logic state of the variable Bat_Trc_Cnct_En output from block 2, which depends on the outcome of the verification of the conditions A-F. In other words, said determinations are operated if the transit of the flow rate 'rhspiit is enabled; otherwise, according to the fashion described in the Figures, the value zero is adopted.

[0101] Thanks to the method according to the invention, it is possible to improve the efficiency of a vehicle with an electric powertrain by recovering the thermal power rejected by the at least one traction component and using it for heating the battery, which in turn decreases the internal electrical resistance and increases the efficiency of the battery. Moreover, this enables reducing the energy consumed for cooling the at least one traction component TRC, since the thermal capacity of the battery BATT is employed for the absorption of the thermal power rejected by the at least one traction component; thus, the flow rate of the heat transfer liquid which returns towards the at least one traction component has temperature conditions which favour cooling the at least one traction component without resorting to the use of a cooling radiator on the branch R1. Ultimately, such an improvement of the energy efficiency increases the driving range of the vehicle.

[0102] Of course, the implementation details and the embodiments may amply vary with respect to what has been described and illustrated herein without departing from the extent of the present invention, as defined by the annexed claims.

Claims

1. CLAIMS1. A method of operating a thermal conditioning circuit (C) of a vehicle with an electric powertrain, the circuit including:- at least one traction component (TRC) of said powertrain traversed by a first flow rate of heat transfer liquid ('rhTrc') in a first flow direction (Fl), said at least one traction component (TRC) including an electric traction motor and / or a transmission connecting an electric traction motor to one or more corresponding drive wheels of the vehicle,- a first circulation pump (TP) having a delivery port upstream of said at least one traction component (TRC) with respect to the first flow direction (Fl) of said heat transfer liquid, the first circulation pump (TP) supplying said first flow rate mTrc) to the at least one traction component (TRC),- a first recirculation branch (Rl) connecting an outlet of the at least one traction component (TRC) with a suction port of the first circulation pump (TP), the first recirculation branch (Rl) being traversed by a first recirculation flow rate (TTIRI),- a heat exchange device (CHL) traversed by a second flow rate mBat) of heat transfer liquid in a second flow direction (F2), wherein the heat exchange device includes a thermal conditioning circuit (BTC) of a battery (BATT) configured to supply one or more electric traction motors of the vehicle's powertrain, wherein the thermal conditioning circuit (BTC) of the battery (BATT) is traversed by said second flow rate mBat') of heat transfer liquid, and further includes an evaporation device supplied with refrigerant fluid and in an operational relationship with, in particular, part of, a refrigeration cycle circuit wherein said refrigerant fluid flows, wherein the evaporation device is in a heatexchange relationship with the thermal conditioning circuit (BTC) of the battery (BATT),- a second circulation pump (BP) having a delivery port upstream of said heat exchange device (CHL) with respect to the second flow direction (F2) of said heat transfer liquid, the second circulation pump (CP) supplying said second flow rate (?iiBat) to said thermal conditioning circuit (BCL) of the battery (BATT),- a second recirculation branch (R2) connecting an output of the thermal conditioning circuit (BCL) of the battery (BATT) with a suction port of the second circulation pump (BP), the second recirculation branch (R2) being traversed by a second recirculation flow rate (mR2),- a first branch (Bl) configured for a transit of a spill flow rate (?iiSpijt) from said first recirculation branch (Rl) towards the suction port of the second circulation pump (BP),- a second branch (B2) configured for a transit of the spill flow rate (^Lspzit) from said second recirculation branch (R2) to said first recirculation branch (Rl), wherein a spill valve (VI) is arranged upstream of the second branch (B2) to regulate the transit of the spill flow rate ('rhspiit') from said second recirculation branch (R2) to said first recirculation branch (Rl), the method includes enabling (Bat_Trc_Cnct_En = 1), through said spill valve (VI), a transit of the spill flow rate i'rhspiit') from an outlet of the conditioning circuit (BTC) of the battery (BATT) through the second branch (R2) to a suction port of the first circulation pump (TP) if each of the following conditions is met:- a thermal power rejected by said at least one traction component (TRC) is not used by one or more receiving users having higher priority for the use ofsaid rejected thermal power (A, Trc_Heat_Rej_HP_Act = 0), in particular for energy efficiency purposes,- the thermal power rejected by said at least one traction component (TRC) is not reserved for one or more receiving users having higher priority for the use of said rejected thermal power (B, Trc_Heat_Rej_HP_Res = 0), in particular for energy efficiency purposes,- the possibility exists (C, Trc_Heat_Rej_Bat_Usbl = 1) of transferring said thermal power rejected by the at least one traction component (TRC) to said battery (BATT),- a critical temperature of said battery has not been reached (D, Crit_Bat_Temp = 0),- it is not expected to incur the need for battery cooling during a corresponding vehicle mission (E, No_Bat_Clg_Exp = 1)- there are no faults (F, No_Comp_Fault =1) in the thermal conditioning circuit (C).

2. The method of claim 1, further including, when the transit of the spill flow rate (?iiSpijt) is enabled, determining a target value (wispzitpgt) of said spill flow rate and heating the battery (BATT) by means of the target value (rii-spiitTgt} of the spill flow rate coming from said at least one traction component (TRC), said determining a target value (rii-spiitTgt} of said tapping flow rate (?iispjit) includes determining the target value as sum of a target value of spill flow rate determined by openloop calculation (riiSpiit 0L Tgt) and a target value of spill flow rate determined by closed-loop calculation ^ spiit_a_Tgt')i the sum being limited superiorly to a maximum value (ritSpiit Max} of said spill flow rate ('rhspiit')and being limited inferiorly to a zero value.

3. The method of claim 1 or claim 2, wherein a possibility exists (Trc_Heat_Rej_Bat_Usbl = 1) of transferring said thermal power rejected by the at leastone traction component (TRC) to said battery (BATT) when a difference (12) between a temperature (TTrcCintOut) of the heat transfer liquid leaving the at least one traction component and a temperature (TBat ctnt Out) of the heat transfer liquid leaving said thermal conditioning circuit (BTC) of the battery (BATT) is greater than, in particular, greater than or equal to (16), a first threshold value (hTTrcHeatUsbt Hi), and wherein no possibility exists (Trc_Heat_Rej_Bat_Usbl = 0) of transferring that thermal power rejected by the at least one traction component (TRC) to said battery (BATT) when the difference (12) between the temperature (TTrcCintOut) of the heat transfer liquid leaving the at least one traction component and the temperature (TBat ctnt Out) of the heat transfer liquid leaving said thermal conditioning circuit (BTC) of the battery (BATT) is less than, in particular less than or equal to (18), a second threshold value (&TTrcHeatUsbi Lo).

4. The method of any of the preceding claims, wherein the critical temperature of said battery (Crit_Bat_Temp = 1) has been reached when a maximum cell temperature (TBat CeuMax} of said battery is greater than, in particular greater than or equal to (24), a third threshold value (TBat CenLim Hi), and wherein the critical temperature of said battery has not been reached (D, Crit_Bat_Temp = 0) when the maximum cell temperature CTBat_ceii_Max') of said battery is less than, in particular less than or equal to (26), a fourth threshold value (TBat_Cell_Lim_Lo)•5. The method of any of the preceding claims, wherein it is not expected to incur the need for battery cooling during a corresponding vehicle mission (No_Bat_Clg_Exp = 1) when a difference (32, &TBat BefCig) between a target value (TBat CeuMax Tgt} of maximum cell temperature of the battery (BATT) and a predicted celltemperature value of the battery at the end of the mission (TBat CeuEndMission) in the absence of cooling is greater than, in particular greater than or equal to (36), a fifth threshold value (&TBat CeU Hi), and wherein it is expected to incur the need for battery cooling during a corresponding vehicle mission (No_Bat_Clg_Exp = 0) when the differenceBefCig) between the target value of maximum cell temperature (TBatCeuMaxTgt') of the battery (BATT) and the predicted cell temperature value of the battery at the end of the mission (TBat CenEndMission) in the absence of cooling is less than, in particular less than or equal to (38), a sixth threshold value (^TBatCeuLo).

6. The method of claim 5, wherein the predicted cell temperature value of the battery at the end of the mission (TBat Cell EndMission) includes a sum (39) of said maximum cell temperature (TBat CeuMax} of the battery and a predicted temperature increase (&TBat Incr) dependent on the mission of the vehicle.

7. The method of claim 6, wherein the predicted temperature increase (&TBat Incr) dependent on the vehicle mission is calculated (41) as a ratio (.QBat_TotX EtEnd Mission)I^Thrm Batr wherein:- QBat_Tot isatotal thermal power generated by said battery (BATT),- AtEnd Mission is a time remaining before the end of the mission,- CThrmBatis a thermal capacity of said battery (BATT), and wherein furthermore:- the total thermal power QBat_Tot generated by the battery (BATT) is calculated as the difference (42) between a thermal power QBat_Hrj rejected by the battery (BATT) and a thermal power QBatAmb_Exg transferred by the battery (BATT) to the external environment as a function(43) of a temperature difference &TBatAmbbetween the battery (BATT) and the external environment,- the temperature difference &TBatAmbbetween the battery (BATT) and the external environment is calculated as the difference (44) between an average cell temperature value TBat CeuMidMissionof the battery (BATT) and an external ambient temperature,^^- the average cell temperature value TBat CenMidMissionis calculated (45, 46, 47, 48) as a ratioBattCellMaxTgt~ ^TBa.t_Cell_Hi~ TBatt_Cell_Max^ / ^r whereinTgattceilMaxTgt is said maximum cell temperature target value of the battery (BATT), &TBat CeuHiis said fifth threshold value, TBatt CeU Maxis said maximum cell temperature of the battery (BATT).

8. The method of any of the preceding claims, wherein said thermal conditioning circuit (C) further includes a plurality of temperature sensors including:- a first temperature sensor (TS_A) configured to detect a temperature (TTrc ctnt Out) of the heat transfer liquid leaving at least one traction component (TRC),- a second temperature sensor (TS_B) configured to detect a temperature (TBatctntIn) of the heat transfer liquid entering the thermal conditioning circuit (BTC) of the battery (BATT), and- a third temperature sensor (TS_C) configured to detect a temperature (TBat ctnt Out) of the heat transfer liquid leaving the thermal conditioning circuit (BTC) of the battery (BATT), wherein there are no faults (F, No_Comp_Fault =) in the thermal conditioning circuit (C) if there are no faults (No_Fault, 52, 53, 54, 55, 56, 57) with each of said first temperature sensor (TS_A), second temperature sensor (TS_B), third temperature sensor (TS_C), spill valve (VI), first circulation pump (TP), and second circulation pump (BP).

9. The method of any of claims 2 to 8, including calculating the target value of the spill flow rate determined by open loop calculation (Thspiit_OL_Tgt) according to the following steps:- determining (91, 92, 93, 94) a raw target value of spill flow rate by means of an open-loop calculation ,• . ,. ™BatTqt*(TBatClntInTat~^BatClntOut)^ SplltOLRawTgUaS a ratio - -7- -- - -y- ,VTrc_Clnt_Out1Bat_Clnt_Out) wherein:TTrccintout isatemperature value of the heat transfer liquid leaving the at least one traction component (TRC),TBat_cint_in_Tgt isatarget value for the temperature of the heat transfer liquid entering the thermal conditioning circuit (BTC) of the battery (BATT),TBat_cint_out isatemperature value of the heat transfer liquid leaving the thermal conditioning circuit (BTC) of the battery (BATT), riiBat_Tgt isatarget value of the second flow rate of heat transfer liquid,- determining a saturated value of the spill flow rate by means of an open-loop calculation (mSpiit 0L Sat Tgt) as the lower (95) of a maximum value of the spill flow rate (riispiit_Max) and the greater among the higher of said raw target value of the spill flow rate determined by an open-loop calculation (ThSpiit 0L Raw Tgt) and the zero value (98),- adopting (SW90) said saturated value of the spill flow rate by means of an open-loop calculation (™spiit_OL_sat_Tgt)asthe target value of the spill flow rate determined by an open-loop calculation0L Tgt) if a transit of a spill flow rate (m-spitt') is enabled (Bat_Trc_Cnct_En = 1),- adopting (SW90) the zero value (99) as the target value of the spill flow rate determined by open loop calculation (riispiit_OL_Tgt} ifatransit of the spill flowrate (Bat_Trc_Cnct_En = 0) is not enabled ('I'hspiit')•10. The method of claim 9, including:- calculating the target value of the spill flow rate determined by closed-loop calculation (riispiit_CL_Tgt') by means of a proportional-integral controller (101) as a function of a difference TBat ctnt InTgt- TBatcintIn(102) between a target value TBat ctnt In Tgtof the temperature of the heat transfer liquid entering the thermal conditioning circuit (BTC) of the battery (BATT) and a current value TBatctntInof the temperature of the heat transfer liquid entering the thermal conditioning circuit (BTC) of the battery (BATT) if a transit of a spill flow rate (I'hspiit') is enabled (Bat_Trc_Cnct_En = 1), wherein the proportional-integral controller (101) includes an upper saturation limit (103) corresponding to a difference mSpUt Max- mSpUt 0L Tgt(105) between the maximum spill flow rate value rii-spiitMax and the target spill flow rate value determined by open-loop calculation riiSpiit 0LTgt, and a lower saturation limit (104) corresponding to the opposite —Thspiit_OL_Tgt °f the target spill flow rate value determined by open-loop calculation mSpUt 0L Tgt- adopting the zero value (109) as the target value of the spill flow rate determined by means of a closed- loop calculation (i’hspiit_CL_Tgt') if a transit of the spill flow rate (I'hspiit') isn°t enabled (Bat_Trc_Cnct_En = 0).

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