A method for the handling of a malfunction of a battery charger for the recharge of a low voltage battery of a vehicle with an electric powertrain, in particular for the limitation of a rotational speed of one or more circulation pumps of a heat transfer liquid of one or more thermal conditioning circuits

Abstract

A method is described for handling a malfunction of a battery charger for recharging a first battery of a vehicle with an electric powertrain, the electric powertrain comprising one or more electric traction motors each operatively connected to one or more corresponding drive wheels, and a second battery configured to power said one or more electric traction motors, the second battery having a supply voltage higher than the first battery, said battery charger being powered by said second battery for recharging said first battery, the vehicle comprising at least one heat transfer liquid thermal conditioning circuit, and each circuit including at least one heat transfer liquid circulation pump, Thanks to the method according to the invention, it is thus possible to increase the vehicle ' s driving range under battery charger malfunction conditions by maintaining the high-voltage network operational for as long as possible through the limitation of the rotational speed of each of the circulation pumps involved in the intervention.

Description

[0001] A method for the handling of a malfunction of a battery charger for the recharge of a low voltage battery of a vehicle with an electric powertrain , in particular for the limitation of a rotational speed of one or more circulation pumps of a heat transfer liquid of one or more thermal conditioning circuits

[0002] TEXT OF THE DESCRIPTION

[0003] Field of the invention

[0004] The present invention relates to vehicles with an electric powertrain, in particular BEV-type vehicles . The invention was developed with particular reference to the thermal management of the vehicle , speci fically to the management of one or more circulation pumps of a heat trans fer liquid of one or more thermal conditioning circuits onboard the vehicle itsel f .

[0005] Prior art

[0006] In a BEV (Battery Electric Vehicle ) with an electric powertrain, there is a coexistence of electrical supply networks comprising a high-voltage network ( e . g . , 800 V) intended for vehicle propulsion and powered by a high-voltage battery, and a low- voltage network ( e . g . , 12 V) powered by a low-voltage battery that supplies part of the non-propulsive loads , such as one or more circulation pumps of one or more heat trans fer liquid thermal conditioning circuits of the vehicle and one or more electric actuators of high- voltage contactors through which the electrical connection is established between the high-voltage battery and one or more electric traction motors of the vehicle ' s electric powertrain . The high-voltage battery is recharged by the electric traction motors during operation in regeneration conditions and by an external charging network when the vehicle is connected to a charging station . The low-voltage battery can only be recharged through an onboard DC-DC charger powered by the high-voltage battery .

[0007] I f the DC-DC charger intended for recharging the high-voltage battery experiences a mal function condition that makes recharging the low-voltage battery not viable , the functions powered by the low-voltage battery remain available as long as the state of charge of the low-voltage battery allows it . Upon depletion o f the low-voltage battery charge , these functions cease to be available , and as described, this implies the immediate stop of the vehicle with no possibility of restarting regardless of the state of charge of the high-voltage battery, since the depletion of the low- voltage battery charge also causes , i . a . , the loss of power to the actuators of the high-voltage contactors , thereby opening the electrical circuit connecting the high-voltage battery to the one or more electric traction motors .

[0008] Within the prior art , the mal function condition of the DC-DC charger intended for recharging the low- voltage battery is not controlled in the evolution thereof . In other words , the discharge evolution of the low-voltage battery under DC-DC charger mal function conditions is left free to progress without any consideration of the consequences of this choice on vehicle autonomy .

[0009] Obj ect of the invention

[0010] The obj ect of the invention is to solve the technical problem previously described . In particular, the obj ect of the present invention is to provide a method that allows managing a malfunction condition of the DC-DC battery charger of a vehicle with an electric powertrain while maintaining the electrical supply to the one or more electric traction motors by the high- voltage battery for as long as possible . Summary of the invention

[0011] The obj ect of the invention is achieved by a method having the features forming the subj ect of one or more of the claims that follow, which form an integral part of the technical disclosure provided herein in relation to the invention .

[0012] Brief description of the figures

[0013] The invention will now be described with reference to the attached figures , provided purely by way of nonlimiting example , and in which :

[0014] - Figure 1 illustrates an exemplary block diagram of a method according to the invention, with particular reference to a preferred embodiment ,

[0015] Figures 2 to 10 correspond to block diagrams illustrating phases and / or aspects of the method according to the invention .

[0016] Detailed description

[0017] As a general premise , the method according to the invention is applicable to a vehicle with an electric powertrain comprising one or more electric traction motors each operatively connected to one or more corresponding drive wheels and a high-voltage battery ( e . g . , 800 V) dedicated to vehicle propulsion and configured to power the one or more electric traction motors . Onboard the vehicle , in accordance with what was described at the beginning of this description, there is a low-voltage battery ( e . g . , 12 V) dedicated to powering non-propulsive loads . In general , the low- voltage battery ( also referred to as the " first battery" hereafter ) has a supply voltage lower ( signi ficantly lower ) than the high-voltage battery ( also referred to as the " second battery" hereafter ) . The first battery is also rechargeable only via a DC-DC charger that is powered by the second battery, thus drawing electrical power for recharging the first battery from the second battery . The second battery, on the other hand, is rechargeable both by the one or more electric traction motors during operation in regeneration mode and — in a manner per se known — by connecting the vehicle to a charging station .

[0018] The vehicle in question thus comprises a high- voltage network dedicated to vehicle propulsion and powered by the second battery, and a low-voltage network powered by the first battery and dedicated to powering part of the non-propulsive loads , including electric actuators of the high-voltage contactors through which electrical current flow from the second battery is enabled .

[0019] The vehicle further comprises one or more heat trans fer liquid thermal conditioning circuits , each comprising one or more circulation pumps of the heat trans fer liquidheat trans fer liquid itsel f .

[0020] Examples of vehicles with such configuration are described, for instance , in Italian patent applications 102024000003928 , 102024000015349 , 102024000016162 .

[0021] That said, a method is defined according to the invention for handling a malfunction of the battery charger for recharging the first battery of a vehicle of the type in question, the method comprising, upon occurrence of a mal function condition of the battery charger that prevents recharging of the first battery and for each thermal conditioning circuit :

[0022] - determining a state of charge ( SoC - State of Charge ) of the first battery,

[0023] - determining a temperature of an environment in heat exchange relationship with the heat trans fer liquid of the thermal conditioning circuit ,

[0024] - determining a limit value of rotational speed for each circulation pump of the thermal conditioning circuit as a function of the state of charge ( SoC ) o f the first battery and the temperature of the environment in heat exchange relationship with the heat trans fer liquid of the thermal conditioning circuit .

[0025] Once each limit value of rotational speed is determined, the method comprises controlling each circulation pump as a function of the corresponding limit value of rotational speed . In particular, thi s includes limiting the rotational speed of each circulation pump to the corresponding limit value o f rotational speed .

[0026] The method according to the invention is highly flexible as it is applicable to a generic configuration of a vehicle with an electric powertrain, regardless o f the number and type of thermal conditioning circuits and regardless of the number of circulation pumps within each circuit . In general , it is preferable that in the case of multiple circulation pumps within the same thermal conditioning circuit , the limit value of rotational speed is applied identically to all circulation pumps .

[0027] By way of example , Figure 1 illustrates a multiple block diagram wherein which reference 1 generally indicates the implementation of the method according to the invention, while the additional references indicate :

[0028] - the implementation of the method according to the invention with respect to a thermal conditioning circuit of the second battery ( reference 1A) , wherein the environment in heat exchange relation with the heat trans fer liquid comprises the second battery itsel f ,

[0029] - the implementation of the method according to the invention with respect to a thermal conditioning circuit of one or more traction units ( reference IB ) , wherein the thermal conditioning circuit of the one or more traction units includes at least a second circulation pump, wherein each traction unit comprises an electric traction motor, an inverter operatively associated with the electric traction motor, and a transmission connecting the electric traction motor to one or more corresponding drive wheels , the transmission comprising a transmission lubricant , and wherein the environment in heat exchange relationship with the heat trans fer liquid comprises - for each traction unit , the inverter, the electric traction motor, and the transmission, in particular the transmission lubricant ( there is , in particular, a radiator for the transmission lubricant traversed - in addition to the transmission lubricant - by the thermovector liquid) ;

[0030] - the implementation of the method according to the invention with respect to a thermal heating circuit of a vehicle cabin ( reference 1C ) , wherein the thermal heating circuit of a vehicle cabin comprises a cabin heater through which the heat trans fer liquid circulates and at least a third circulation pump . In this case , the environment in heat exchange relationship with the heat trans fer liquid is the external environment , given that a cabin air flow that impinges upon the heater originates from the external environment .

[0031] Each of the implementations 1A, IB, 1C is detailed in the subsequent figures 2 to 10 . It should be noted that the implementation of the method according to the invention may involve any selection of the thermal conditioning circuits listed above ( even j ust one o f them) and / or may include implementation on additional thermal conditioning circuits present onboard the vehicle , provided they comprise a heat trans fer liquid circulation pump or an operative machine powered by the first battery ( low voltage ) . It should also be noted that in some vehicle configurations , the thermal conditioning circuits may be communicating or made communicating for reasons unrelated to the method according to the invention, thus the heat trans fer liquid may be shared between two or more of the thermal conditioning circuits .

[0032] With reference to figure 2 , diagram 10 , in the case of implementation on a thermal conditioning circuit of the second battery (high voltage ) including at least a first heat trans fer liquid circulation pump , a first limit value of rotational speed nP umpspd Batt Lim is defined, corresponding to the output of a switch SW10 . The switch SW10 is subj ect to a control variable DCDC_Critical_Error that assumes a logical state " 1" ( TRUE ) when a mal function of the battery charger assigned to recharging the first battery occurs , and " 0" ( FALSE ) when no mal function o f the battery charger assigned to recharging the first battery occurs . The reference SWC indicates the condition dependent on the logical state of the variable DCDC_Critical_Error that governs the switch SW10 ( in this case SWC : DCDC_Critical_Error = TRUE ) .

[0033] In the event of a mal function, thus the event relevant for the purposes of the method of the invention, the output of the switch SW 10 corresponds to what is visible in figure 2 , wherein the limit value npumpspd Batt Lim applicable to the one or more circulation pumps of the high-voltage battery thermal conditioning circuit is assumed equal to the output value nP umpspd_Batt_LimRaw of a map M10 , corresponding to a limit value of rotational speed determined as a function of a state of charge SOCLv Batt of the first battery ( low voltage ) , and a temperature THv Batt of the second battery, given that the environment in heat exchange relation with the heat trans fer liquid corresponds to the second battery itsel f . The map MI O provides the limit value nPumpSpd_Batt_LimRaw through curves that are a function of the state of charge SOCLv Batt and parameteri zed with respect to the value of the temperature THv Batt • By way of example , the map MI O in figure 2 shows the qualitative trend of four curves npumpspd— Batt— LimRaw- S OCLv_ Batt parameteri zed as a function of temperature values of the second battery THv Batt i , THv_Batt_2 , THV_ Batt- 3 , THv_Batt_4 listed in increasing order o f temperature ( thus THv_Batt_i < THv_Batt_2 < THv_Batt_3 < THV_ Batt_ 4 ) • Qualitatively, the limit value nPumpSpd_Batt_LimRaw decreases as the state of charge SOCLv Batt of the first battery decreases , because for low state of charge values it is necessary to limit the electrical power draw from the first battery, thus reducing the rotational speed of the one or more circulation pumps , and increases as the temperature THv Batt rises so as to progressively raise the rotational speed limit as the temperature increases and avoid damage to the high- voltage battery . Figure 2 even illustrates , for the temperature THv_Batt_4 , the case of a limit nPumpSpd_Batt_LimRaw invariant with respect to SOCLv Batt , thereby representing the case of a battery temperature so high as to make limitation impractical even at very low state of charge levels S OCLv Batt -

[0034] In the opposite event , where no mal function occurs , the output of the switch SW 10 corresponds to the alternative to what shown in figure 2 , wherein the limit value nPumpSpd Batt Lim applicable to the one or more circulation pumps of the high-voltage battery thermal conditioning circuit is assumed equal to a limit value Battery_PumpSpd_NoLim of rotational speed independent of S OCLV Batt and THv Batt , but - on the contrary constant and available as such on the vehicle ' s onboard data network . With reference to figure 3 , diagram 20 , in case of implementation on a thermal conditioning circuit of one or more traction units of the electric powertrain including at least a second circulation pump, and wherein each traction unit comprises an electric traction motor, an inverter operatively associated with the electric traction motor, and a transmission connecting the electric traction motor to one or more corresponding drive wheels , the transmission comprising a transmission lubricant , a second limit value of rotational speed nPumpspd ire Lim is defined, corresponding to the output of a switch SW20 . The switch SW20 i s subj ect , like the switch SW10 , to the control variable DCDC_Critical_Error that assumes a logical state " 1" ( TRUE ) when a mal function of the battery charger intended for recharging the first battery occurs , and " 0" ( FALSE ) when no mal function o f the battery charger intended for recharging the first battery occurs . Again, the reference SWC indicates the condition dependent on the logical state of the variable DCDC_Critical_Error that governs the switch SW20 ( in this case SWC : DCDC_Critical_Error = TRUE ) .

[0035] In the event of a mal function, thus the event relevant for the purposes of the method of the invention, the output of the switch SW20 corresponds to what is visible in figure 3 , wherein the limit value npumpspd ire Lim applicable to the one or more circulation pumps of the thermal conditioning circuit of the one or more traction units is assumed equal to a limit value npUmpspd Trc LimRaw corresponding to the greater value (block 22 , MAX ) between a first limit value of rotational speed numpSpd inv Lim that is a function of the state o f charge SOCLv Batt of the first battery and an inverter temperature TInv, a second limit value of rotational speed numpSpd Mot Lim that is a function of the state o f charge SOCLv Batt of the first battery and an electric traction motor temperature TMot, and a third limit value of rotational speed nPumpSpd Trnsmoii Lim that is a function of the state of charge SOCLv Batt of the first battery and a transmission lubricant temperature TTrnsmOii . This means that the limit value nPumpSpd ire LimRaw is chosen to be equal to the limit value resulting from the most severe conditions , so as to ensure the required thermal conditioning .

[0036] The dependence on the temperatures TInv, TMot, TTrnsmoii is j usti fied by the fact that the environment in heat exchange relation with the heat trans fer liquid of the thermal conditioning circuit of the one or more traction units comprises the inverter, the transmission lubricant , and the electric traction motor .

[0037] In the opposite event , where no mal function occurs , the output of the switch SW20 corresponds to the alternative to what shown in figure 3 , wherein the limit value nPumpSpd ire Lim applicable to the one or more circulation pumps of the thermal conditioning circuit of the one or more traction components is assumed equal to a limit value of rotational speed Traction_PumpSpd_NoLim independent of SOCLv Batt and THV Batt t but - on the contrary - constant and available as such on the vehicle ' s onboard data network .

[0038] The subsequent figures 4 to 6 illustrate the determination of the limit values nPumpSpd inv Lim, nPumpSpd_ Mot_ Lim, nP ump3pd Trnsmoii— Lim as a function of the temperatures TInv, TMot, TTrnsmoii ( respectively) and the state of charge SOCLv Batt -

[0039] With reference to figure 4 , diagram 30 , the limit value nPumpSpd inv Lim corresponds to the output data of a map M30 that provides the value nPumpSpd inv Lim as a function of the state of charge SOCLv Batt of the first battery ( low voltage ) , and the inverter temperature TInv. For the purposes of the method according to the invention, the inverter temperature value TInvused as input data for map M30 corresponds to the highest (block 32 , MAX ) among the inverter temperature values detected for each inverter of the powertrain . By way o f example , figure 4 refers to a vehicle with a quad-motor powertrain comprising four traction units each including an inverter, an electric traction motor and a transmission with transmission lubricant . The indices A, B, C, D associated with the references in figure 4 individually designate the traction units and their respective components , therefore the temperature TInvis equal to the highest among the values TInv A, TInv B, Tinv c, TInv Dof the four inverters .

[0040] The map M30 provides the limit value nP ump Spd inv Lim through curves that are a function of the state of charge SOCLv Batt and parameteri zed with respect to the value of the inverter temperature TInv. By way of example , the map M30 in figure 4 shows the qualitative trend of four curves nP ump Spd inv Lim_SOCLv Batt parameteri zed as a function of inverter temperature values TInv p, T inv T inv 3 , T inv4 listed in increasing order of temperature ( thus Tmv_i < Tmv_2 < Tmv_3 < Tmvj ) . Qualitatively, the limit value nPumpSpd inv Lim decreases as the state of charge SOCLv Batt o f the first battery decreases , because for low state o f charge values it i s necessary to limit the electrical power draw from the first battery, thus reducing the rotational speed o f the one or more circulation pumps , and increases as the temperature Tinvrises so as to progressively raise the rotational speed limit as the inverter temperature increases and avoid damage to the inverter itself .

[0041] With reference to figure 5 , diagram 40 , the limit value nP ump Spd Mot Lim corresponds to the output data of a map M40 that provides the value nP ump Spd Mot Lim as a function of the state of charge SOCLv Batt of the first battery ( low voltage ) , and the electric traction motor temperature TMot. The map M40 provides the limit value npumpspd Mot Lim through curves that are a function of the state of charge SOCLv Batt and parameteri zed with respect to the value of the electric traction motor temperature TMOL •

[0042] For the purposes of the method according to the invention, the electric traction motor temperature value TMotused as input data for map M40 corresponds to the highest (block 42 , MAX ) among the electric traction motor temperature values detected for each electric traction motor of the powertrain . By way of example , figure 5 again refers to a vehicle with a quad-motor powertrain comprising four traction units each including an inverter, an electric traction motor and a transmission with transmission lubricant . The indices A, B, C, D associated with the references in figure 4 individually designate the traction units and their respective components , therefore the temperature TMotis equal to the highest among the values TMotA, TMotB , TMot c , TMotD of the four electric traction motors .

[0043] By way of example , the map M40 in figure 5 shows the qualitative trend of four curves nP ump Spd Mot Lim- S OCLV Batt parameteri zed as a function of electric traction motor temperature values TMoti, TMot2, TMot3, TMot4 listed in increasing order of temperature ( thus TMot_i < TMo t_2 < TMo t-3< TMo t-4) • Qualitatively, the limit value nP ump Spd Mot Lim decreases as the state of charge S OCLV Batt of the first battery decreases , because for low state of charge values it is necessary to limit the electrical power draw from the first battery, thus reducing the rotational speed of the one or more circulation pumps , and increases as the temperature TMotincreases so as to progressively increase the rotational speed limit as the electric traction motor temperature increases and avoid damage to the electric traction motor of the traction unit .

[0044] With reference to figure 6 , diagram 50 , the limit value nPumpspd imsmoii Lim corresponds to the output data o f a map M50 that provides the value nP ump Spd imsmoii Lim as a function of the state of charge SOCLv Batt of the first battery ( low voltage ) , and the transmission lubricant temperature TTrnsmOii.

[0045] For the purposes of the method according to the invention, the electric traction motor temperature value TTrnsmOii used as input data for map M50 corresponds to the highest (block 52 , MAX ) among the transmission lubricant temperature values detected for each transmission . By way of example , figure 6 again refers to a vehicle with a quad-motor powertrain comprising four traction units each including an inverter, an electric traction motor and a transmission with transmission lubricant . The indices A, B, C, D associated with the references in figure 4 individually designate the traction units and their respective components , therefore the temperature TMotis equal to the highest among the values TTrnsmOii_A, TTrnsmOii_B, TTrnsmOii c, TT rnsmoii D of the transmission lubricants of the four transmissions .

[0046] The map M50 provides the limit value nPumpspd Trnsmoii Lim through curves that are a function of the state of charge SOCLv Batt and parameteri zed with respect to the value of the transmission lubricant temperature TTrnsmoii • By way of example , the map M50 in figure 6 shows the qualitative trend of four curves nP umpspd_Trnsmoii_Lim- S OCLv_Batt parameteri zed as a function of transmission lubricant temperature values TTrnsmoii i, TTrnsm0ii_2 , TT rnsmoii_3 , TT rnsmoii_4 listed in increasing order Of temperature ( thUS TT rnsmOil_l < TT rnsm0il_2 < TT rnsm0il_3 < Timsmoii 4 ) • Qualitatively, the limit value npUmpspd_Trnsmoii_Lim decreases as the state of charge SOCLV Batt of the first battery decreases , because for low state of charge values it is necessary to limit the electrical power draw from the first battery, thus reducing the rotational speed of the one or more circulation pumps , and increases as the temperature Irrnsmoii increases so as to progressively raise the rotational speed limit as the transmission lubricant temperature increases and avoid damage to the transmission itsel f .

[0047] With reference to figure 7 , diagram 60 , in the case of implementation of the method according to the invention on a vehicle cabin heating circuit comprising a cabin heater through which the heat trans fer liquid circulates and at least a third circulation pump, a third limit value of rotational speed nPumpSpd cabHtr Lim is defined, corresponding to the output of a switch SW60 . The switch SW60 is subj ect , like switches SW10 , SW20 , to the control variable DCDC_Critical_Error that assumes a logical state " 1" ( TRUE ) when a mal function of the battery charger intended for recharging the first battery occurs , and " 0" ( FALSE ) when no mal function of the battery charger intended for recharging the first battery occurs . Again, the reference SWC indicates the condition dependent on the logical state of the variable DCDC_Critical_Error that governs the switch SW60 ( in this case SWC : DCDC_Critical_Error = TRUE ) .

[0048] In the event of a mal function, thus the event relevant for the purposes of the method of the invention, the output of the switch SW60 corresponds to what is visible in figure 7 , wherein the limit value npumpspd cabHtr Lim applicable to the at least one third circulation pump of the vehicle cabin heating circuit is assumed equal to a raw limit value nP ump Spd_cabHtr_LimRaw .

[0049] In the opposite event , where no mal function occurs , the output of the switch SW60 corresponds to the alternative to what shown in figure 7 , wherein the limit value nPumpSpd cabHtr Lim applicable to the one or more circulation pumps of the vehicle cabin heating circuit is assumed equal to a rotational speed limit value CabinHeater_PumpSpd_NoLim independent of SOCLv Batt , nor of an external ambient temperature TAmb, but - on the contrary - constant and available as such on the vehicle onboard data network .

[0050] The subsequent figure 8 , diagram 70 , is representative of the determination of the raw value nPumpsPd_cabHtr_LimRaw which, as described, comes into play when a mal function of the battery charger occurs . In detail , the raw value nPumpSpd_cabHtr_LimRaw (which becomes the third limit value nPumpSpd_cabHtr_Lim in case of mal function) comprises :

[0051] - a nominal limit value nPumpSpd_cabHtr_LimNorm that is a function of the state of charge SOCLv Batt of the first battery and the external ambient temperature TAmb i f there is no request for thermal conditioning of the vehicle cabin that requires priority ful fillment,

[0052] - a priority limit value nPumpSpd_cabHtr_Limspec that is a function of the state of charge SOCLv Batt of the first battery and the external ambient temperature TAmb i f there is at least one request for thermal conditioning of the vehicle cabin that requires priority ful fillment . The priority limit value nPumpSpd_cabHtr_Limspec is always higher than the nominal limit value nP umpspd_cabHtr_LimNorm for the same state of charge S OCLV_Batt of the first battery and external ambient temperature TAmb •

[0053] This is exempli fied in figure 8 by a switch SW70 subj ect to a control variable Special_Cabin_Conditioning_Active that assumes a logical state " 1" ( TRUE ) when there is at least one request for thermal conditioning of the vehicle cabin that requires priority ful fillment , and " 0" ( FALSE ) when there is no request for thermal conditioning of the vehicle cabin that requires priority ful fillment . The reference SWC70 indicates the condition dependent on the logical state of the variable Special_Cabin_Conditioning_Active that governs the switch SW70 ( in this case SWC70 :

[0054] Special_Cabin_Conditioning_Active = TRUE ) .

[0055] In the event that there is at least one request for thermal conditioning of the vehicle cabin that requires priority ful fillment

[0056] ( Special_Cabin_Conditioning_Active = TRUE ) , the output of the switch SW70 corresponds to what is visible in figure 8 , wherein the limit value nPumpSpd_cabHtr_LimRaw is assumed equal to the value nPump Spd_cabHtr_LimsPec .

[0057] In the opposite event , where there is no request for thermal conditioning of the vehicle cabin that requires priority ful fillment

[0058] ( Special_Cabin_Conditioning_Active = FALSE ) , the output of the switch SW70 corresponds to the alternative to what shown in figure 8 , wherein the limit value nPumpsPd_cabHtr_LimRaw applicable to the one or more circulation pumps of the vehicle cabin heating circuit is assumed equal to the value nPump Spd_cabHtr_LimNorm .

[0059] For the purposes of the method according to the invention, the at least one request for thermal conditioning of the vehicle cabin that requires priority ful fillment comprises :

[0060] - a request for heating of the vehicle cabin under external temperature conditions below a threshold value , preferably below 10 ° C, even more preferably in combination with a request for internal cabin temperature of at least 30 ° C ( corresponding, generally, to the issuance of a "HI" temperature command on the control panel of the cabin thermal conditioning system) , a circumstance that is typically associated with management aimed at minimi zing the time required to ful fill the request by the control unit dedicated to managing the cabin thermal conditioning system;

[0061] - a request for defogging of a glass surface of the vehicle , preferably of a vehicle windshield . Again, this is a circumstance that is typically associated with management aimed at minimi zing the time required to ful fill the request by the control unit dedicated to managing the cabin thermal conditioning system .

[0062] For requests for thermal conditioning of the vehicle cabin that require priority ful fillment , it is therefore planned to request the maximum possible flow rate from the circulation pump ( s ) of the cabin thermal conditioning circuit , for delivery to the cabin heater , since their ful fillment is considered critical in terms of comfort and / or vehicle driving safety . In this perspective , a limitation of the performance of the one or more circulation pumps is generally not compatible with the needs related to comfort and / or driving safety .

[0063] The subsequent figures 9 and 10 , diagrams 80 , 90 illustrate a preferred mode of determining the limit values nPumpspd_ CabHtr_LimNorm and nP umpspd_ _CabHtr_LimSpec f respectively . Both values are extracted from a corresponding map M8 0 ( nP ump Spd_cabHtr_LimNorm ) , M90

[0064] ( nP umpSpd_cabHtr_Limspec ) as a function of the state of charge SOCLV Batt of the first battery ( low voltage ) , and the external ambient temperature TAmb . Both maps M80 , M90 provide the respective limit values nPumpSpd_cabHtr_LimNorm and nPumpSpd_cabHtr_Limspec through curves that are a function of the state of charge SOCLv Batt and parameteri zed with respect to the value of the external ambient temperature TAmb - By way of example , the maps M80 , M90 in figures 9 , 10 show the qualitative trend of four CUrVe S npLirrpppj cabH _rpprrjjc r rr—SOCLV_ Batt and npumpSpd_ CabHtr_ LimSpec- SOCLV Batt parameteri zed as a function of external ambient temperature values TAmb_i , TAmb-2, TAmb-3, TAmb-4listed in increasing order of temperature ( thus TAmb I < TAmb 2 < TAmb 3 < TAmb 4 ) • Qualitatively, the limit values n PumpSpd CabHtr LimNorm- S OCLV Batt and npumpSpd CabHtr LimSpec - SOCLV_ Batt decrease as the state of charge SOCLv Batt of the first battery decreases , because for low state of charge values it is necessary to limit the electrical power draw from the first battery, thus reducing the rotational speed of the one or more circulation pumps , and increases as the temperature TAmb decreases so as to always satis fy a cabin heating requirement in the event of low temperatures . The compari son between maps M80 and M90 is immediately visible as previously observed, namely that the priority limit value npumpspd_cabHtr_LimsPec is always higher than the nominal limit value npumpspd_cabHtr_LimNorm for the same state of charge S OCLV_Batt of the first battery and external ambient temperature TAmb, so as to have a greater heat trans fer liquid flow rate in the presence of a vehicle cabin thermal conditioning request requiring priority ful fillment .

[0065] From the preceding description, the flexibility and modularity of the method according to the invention is also evident : for each thermal conditioning circuit to be involved in limiting the rotational speed of the respective ( one or more ) circulation pump ( s ) , it is suf ficient to acquire the temperature ( one or more depending on the circuit characteristics ) of the environment in heat exchange relation with the thermovector liquid, in addition to the SOCLv Batt data and the logical state of the variable DCDC_Critical_Error .

[0066] Thanks to the method according to the invention, it is thus possible to increase the vehicle ' s driving range under battery charger mal function conditions by maintaining the high-voltage network operational for as long as possible through the limitation of the rotational speed of each of the circulation pumps involved in the intervention - here preferably by enforcing the limits npump5pj npumpppj pr:Limz npumpspd_CabHtr_Lim •

[0067] Naturally, the implementation details and embodiments may be widely varied with respect to what has been described and illustrated without thereby departing from the scope of the present invention as defined by the attached claims .

Claims

CLAIMS1 . A method for the handling of a mal function of a battery charger for the recharge of a first battery of a vehicle with an electric powertrain, the electric powertrain comprising one or more electric traction motors , each operatively connected to one or more corresponding drive wheels , and a second battery configured to power said one or more electric traction motors , the second battery having a higher supply voltage than the first battery, said battery charger being powered by said second battery for the recharge of said first battery, the vehicle comprising at least one heat trans fer liquid thermal conditioning circuit , and each circuit including at least one heat transfer fluid circulation pump, the method including, upon the occurrence of a mal function condition of said battery charger ( DCDC_Critical_Error = 1 ) such as to impede the recharge of said first battery, and for each thermal conditioning circuit :- determining a state of charge ( SOCLv Batt ) of the first battery,- determining a temperature ( THv Batt , TInv A, TInv B,T lnv C , T lnv D , TMot TMOB B , Twot C , TMOB D , TprnsmOil A,TTmsmoii_B , TTrnsmoii_c, TTrnsmOii_D, Twith ) of an environment in heat exchange relationship with the heat trans fer liquid of the thermal conditioning circuit ,- determining a limit value of rotational speed ( npumpSpd_Batt_Lim, npumpspd_Trc_Lim, npumpspd_CabHtr_Lim ) for each circulation pump of the thermal conditioning circuitaccording to the state of charge of the first battery ( SOCLV Batt ) and of said temperature ( THVBatt , TInv A, TInv B,T lnv C , T jnvp , Twot A, Twot B , Twot C , TMOB ThrnsmOil ArTTrnsmOil B , ThrnsmOil C , ThrnsmOil D r Twith ) of the environment in heat exchange relationship with the heat trans fer liquid of the thermal conditioning circuit .2 . The method of claim 1 , including controlling each circulation pump as a function of the corresponding limit value of rotational speed( npumpSpd— Batt— Lim, n PumpSpd— Trc_ Lim, npumpSpd_ CabHtr_ Lim ) •3. The method of claim 1 or claim 2 , wherein at least one thermal conditioning circuit includes a thermal conditioning circuit of said second battery including at least one first circulation pump for said heat trans fer liquid, said environment including said second battery, so that said temperature includes a temperature of said second battery ( THv Batt ) •4 . The method of any of the foregoing claims , wherein said at least one thermal conditioning circuit includes a thermal conditioning circuit of one or more traction units of said electric powertrain including at least one second circulation pump, each traction unit comprising an electric traction motor, an inverter operatively associated with the electric traction motor and a transmission connecting the electric traction motor traction to one or more corresponding drive wheels , the transmission including a transmission lubricant , wherein said environment comprises the inverter, the transmission and the electric traction motor, so that that temperature comprises an inverter temperature(Tinv) , a transmission lubricant temperature (TTrnsmOii) and an electric traction motor temperature (TMot) , and wherein said limit value of rotational speed (nPumpspd ire Lim) is the highest value (22) of a first limit value of rotational speed (nPumpSpd_Trc_inv_Lim) function of the state of charge of the first battery (SOCLV Batt) and of the inverter temperature (TInv) , a second limit value of rotational speed (nPumpSpd ire Mot Lim) function of the state of charge of the first battery (SOCLV Batt) and the electric traction motor temperature (TMot) , and a third limit value of rotational speed ( nPumpspd_Trc_Trnsmoii_Lim) function of the state of charge of the first battery (SOCLVBatt) and the transmission lubricant temperature (TTrnsmOii) .

5. The method of claim 4, wherein:- the inverter temperature (TInv) is the highest (32) of the inverter temperature values (TInv A, TInv B, Tinv c, Tinv D) detected for each inverter of the powertrain,- the electric traction motor temperature (TMot) is the highest of the electric motor temperature values (TMot A, TMotBz TMotc, TMotD) detected for each electric traction motor of the powertrain,- the transmission lubricant temperature (TTrnSmoii) is the highest of the transmission lubricant temperature values ( TTrnSmoii_A, TTrnSmoii_B, TTrnSmoii_c, Tirnsmoii D) detected for each transmission of the powertrain .

6. The method of any of the foregoing claims, wherein the at least one thermal conditioning circuit includes a heating circuit of a vehicle cabin includinga cabin heater through which said heat transfer liquid circulates and at least one third circulation pump, wherein said limit value of rotational speed (nPumpspd cabHtr Lim) for the at least one third circulation pump includes: a nominal limit value (nPumpSpd_cabHtr_Lim_Norm) depending on the state of charge of the first battery (SOCLV Batt) and an external ambient temperature (TAmb) if there is no requirement for thermal conditioning of the vehicle cabin ( Special_Cabin_Conditioning_Active = 0) that requires priority fulfilment, a priority limit value (nPumpSpd_cabHtr_Lim_spec) depending on the state of charge of the first battery (SOCLV Batt) and the temperature of the external environment (TAmb) if there is at least one requirement for thermal conditioning( Special_Cabin_Conditioning_Active = 1) of the vehicle cabin that requires priority fulfilment, the priority limit value (nPumpSpd_cabHtr_Lim_spec) being higher than the nominal limit value (nPumpSpd_cabHtr_Lim_Norm) with the same state of charge of the first battery (SOCLV Batt) and with the same external ambient temperature (TAmb) •7. The method of claim 6, wherein said at least one request for thermal conditioning of the vehicle passenger compartment requiring priority performance includes :- a request for heating of the vehicle cabin under conditions where the outside temperature is below a threshold value, preferably below 10 °C, even more preferably in combination with a demand for an interiortemperature of at least 30 °C,- a request for defogging of a glass surface of the vehicle, preferably a windshield of the vehicle.

8. The method of claim 2, wherein controlling each circulation pump according to the corresponding limit value of rotational speed (npumpspd_npumpspd_ prcL±m, npUmpspd cabHtr Lim) includes limiting the rotational speed of each circulation pump to the corresponding limit value of rotational speed.

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