FR2973298A1 - Method for heat regulation by refrigerant e.g. carbon dioxide, in lithium-ion battery of hybrid vehicle i.e. car, involves adjusting temperature of battery depending on environmental temperature of battery and based on damage of battery - Google Patents

Abstract

The method involves determining phase e.g. usage phase, of life of a high voltage traction battery i.e. lithium-ion battery, and determining a thermal sate e.g. cold state, of the battery from a set of thermal states based on the temperature of the battery. The temperature of the battery is adjusted as function of the phase of the life of the battery and the determined thermal state depending on intra-cell and inter-cell temperature gradients, depending on environmental temperature of the battery and based on damage of the battery.

Description

METHOD FOR THERMALLY REGULATING A HIGH VOLTAGE TENSION BATTERY OF A HYBRID VEHICLE

Field of the invention

The present invention relates to the field of automotive construction. The present invention relates more particularly to a method 1 o thermal regulation of a high voltage traction battery of a hybrid vehicle.

State of the art

15 The economic (fuel price) and environmental (pollutant and greenhouse gas) pressures are driving the current trend towards the development of electric or hybrid powertrain vehicles (in this case using two types of fuel). motors, in series, in parallel or in power bypass: internal combustion thermal engine 20 and electric motor).

Hybrid and electric vehicles comprise a high voltage traction battery, necessary to make the vehicle move: for an electric vehicle, by supplying the electric motor (s) with the only onboard energy source. ; in the case of a hybrid vehicle, apart from the engine to inhibit any polluting emissions or to boost the performance of the engine by providing additional torque or mechanical power.

Such a battery heats up in operation (Joule effect, thermochemistry), in charge, ... according to the conditions of use (current draws, ...). Due to the maximum T ° levels required by the battery, it has its own needs for thermo-management: in fact, the battery can not withstand, for its lifetime and dependability, a T ° beyond above 40 ° C to 45 ° C. Battery protection strategies are commonly implemented by its control and control electronics (hereinafter referred to as a battery computer) in order to protect it from an excessive rise in its temperature. Thus, from a temperature of, for example, 50.degree. C., its performances begin to be reduced as a function of the variation of its temperature and, if the battery reaches a temperature as high as, for example, 60.degree. C., its contactors open and the battery becomes unavailable.

1 o In order to cool the battery in optimal conditions even in extreme life situations, its thermo-management is increasingly using direct refrigerant via a bypass of the air conditioning system of the vehicle. This mode of cooling is justified by the increased solicitation of the battery on full hybrid rechargeable vehicles, 15 which are required in particular: - a long autonomy in ZEV (up to sometimes 50 to 60km or 100km), breaking with respect to vehicles called mid or full-hybrid first-generation non-refillable; longitudinal dynamic performances making it possible to face in electrical mode all the urban situations, even peripheral and extra-urban situations (insertion into the traffic, acceleration, overtaking, etc.) without, in the case of a hybrid vehicle, use the heat engine to maximize the gain in consumption; the provision of thermal comfort (heating and refrigeration of the passenger compartment) equivalent to a conventional vehicle, in particular in all-electric mode, which imposes on the traction battery, in addition to moving the vehicle, supply electric consumers of type electric air heater outside entering the passenger compartment or electric compressor of the air conditioning circuit; A required lifespan of the traction battery that can be as high as that of the vehicle (10 to 15 years and 200 to 300,000 km), which makes it necessary in particular to thermoregulate the battery at the lowest possible temperature (in its optimum operating range) under all conditions of use.

Refrigeration allows high cooling performance of the high-voltage traction battery, with a favorable energy balance thanks to a coefficient of performance generally taking values from 1.8 to 3.5 for the usual refrigeration at 25 to 40 ° C. of external T °, and which can rise to values of 5 to 8 by a clement ambient T ° (5 to 20 ° C) for situations of usual life where the battery high traction tension needs to be cooled. In addition to its favorable energy balance, this mode of thermo-management can also be justified and be preferred to other modes (cooling by outside air or interior air, 1 o water cooling) for the following reasons: - independence from this system of thermo-management to the situation in the passenger compartment (cabin air polluted by cigarette smoke or dust, open windows, air conditioning group settings by the user of the vehicle not always favorable to the thermal of the 15 drums, ...) ; - its isolation from the passenger compartment, for operational safety and security purposes; the absence of acoustic nuisance, a particularly sought-after service in an electric or full hybrid vehicle in electrical running; - its low intrusion into the installation under hood and / or underbody and / or in the passenger compartment of the vehicle: no air ducts large section or air blower to implant, no additional heat exchanger; the additional cost generated, controlled with respect to these other modes of thermo-management.

Thus, more and more hybrid (or even electric) vehicles, with high performances and performances in dynamics or autonomy, adopt as thermo-management mode refrigeration of the direct traction battery by refrigerant fluid. contact with the active cells of the battery. This battery then consists of an assembly of cells (place where the production, storage and release of electrical energy take place) between which may be (or not: in this case the housing or the wall of each cell plays this role) thermal conduction plates, bringing the calories up to one (or more) plate type heat exchanger or flat or cylindrical or coil type, which here plays the same role as the evaporator of the group of air-conditioning of the passenger compartment, absorbing the calories released in each cell by the Joule effect and by the exothermic thermochemical reactions taking place there, thanks to the upstream expansion and the evaporation of a refrigerant (R134a, CO2, HFO -1234yf, ...) within this exchanger, controlled by a dedicated pressure regulator (or a calibrated pressure switch and / or thermostatic orifice type valve). The principle is to absorb, by the evaporation of the refrigerant fluid from a derivation of the circuit 1 o air conditioning of the vehicle, the heat flow released by Joule effect by the cells of the battery during its operation. For this purpose, the calories released by the cells and transmitted by conduction to one side of a wall of the battery evaporator, are absorbed, on the other side of this wall of the battery evaporator, by the forced evaporation of the fluid. refrigerant. The exchange of heat is thus directly in the battery in contact between the cells and the internal evaporator battery. These calories are then transferred to the condenser of the air conditioning circuit of the vehicle, which evacuates them, by conduction and convection, to the flow of outside air passing through it, thanks to the advance of the vehicle, possibly assisted by the rotation of the motor unit. fan (GMV).

The cells, the evaporator, any conduction plates and the battery computer, are enclosed in a housing, all acting as a battery pack. In addition to thermoregulation of the battery, one of the challenges to be overcome is the implantation of such a battery, of large volume conditioned by the high number of cells to be loaded to provide the energy and electrical power required by the performances and performances. expected. The implantation retained is outside the vehicle under the vehicle body, so as not to impact and therefore to maintain the same benefits of habitability and volume trunk as thermal declination (unhybridized ) of the vehicle, but also for safety purposes vis-à-vis the passenger compartment and its occupants, in case of malfunction, short-circuit or thermal runaway of the battery. The difficulty posed is then to install the large volume of the battery (several tens of liters) in a sub-crate environment already loaded by the implantation of the electrical components associated with hybridization of the vehicle (electric motors and their inverters, electronic power, charger), the fuel tank (gasoline, diesel, LPG, ...), the exhaust line, the engine's depollution elements that constitute it (oxidation catalysts, NOx trap, particulate filter , additive tank type SCR or AdBlue, ...) and the silencer, etc. ... while reducing the diversity with the thermal version of the vehicle in order to control the additional costs generated by the hybridization. In particular, in addition to controlling diversity with the non-hybrid version, the functional constraints associated with the escape problem arise. The exhaust duct can not bypass the battery (given its large size) because of the loss of efficiency that it would generate in terms in particular of back pressure (total pressure drop of the exhaust line, directly impacting the performance of the engine) and temperature (efficiency of the pollution control systems). The resolution of this difficult equation requires the installation of the traction battery in transverse position under the vehicle, straddling the exhaust line, and therefore in geometric proximity (deflections of the line) but especially thermal with it. If it is not possible to move the exhaust line far away from the battery (at most a few centimeters), its thermal radiation can be attenuated by the use of insulators or thermal screens, which are expensive and to the relative efficiency given the temperature differences involved: from 80 to 300 ° C along the exhaust line and the lowest possible temperature (at most 40 ° C) for the battery.

The prior art knows, by the French patent application No. 2,911,220 (Peugeot Citroën Automobiles), a device and method for heating a hybrid vehicle.

The prior art also knows, by the French patent application No. 2,830,926 (Peugeot Citroën Automobiles), a thermal regulation device for a motor vehicle, in particular of electric or hybrid type.

Presentation of the invention

The present invention intends to overcome the drawbacks of the prior art by proposing a refrigerant thermal regulation method of a high-voltage traction battery of a hybrid vehicle.

To this end, the present invention relates, in its most general sense, to a refrigerant fluid thermal regulation method of a high voltage traction battery of a hybrid vehicle, said battery comprising a plurality of cells, characterized in that what it comprises: a step of determining a life phase of said battery among a plurality of life phases; a step of determining a thermal state of said battery from among a plurality of thermal states, as a function of the temperature of said battery; and a step of adjusting the temperature of said battery as a function of said determined life phase and said thermal state, as a function of thermal gradients within and between cells, as a function of the environmental temperature of the battery and depending on its damage.

According to one embodiment, the said life phases are chosen from the following group: "Use", "Fault management", "Not used" 25 and "Diagnosis".

According to one embodiment, said thermal states are chosen from the following group: "cold battery", "warm battery" and "hot battery".

Preferably, the temperature of said battery is measured every 100 ms to determine the thermal state of said battery.

Advantageously, the method further comprises a step of determining the thermal losses of said battery. Preferably, the determination of the thermal losses of said battery is activated every 10 to 100 ms.

According to one embodiment, said battery is heated by implanted electrical resistances in direct contact with said cells of the battery. The present invention also relates to a battery pack for carrying out the method. Preferably, the battery assembly is located under the body of a vehicle and in proximity with the exhaust line of said vehicle.

The present invention also relates to a hybrid vehicle having a battery pack.

The method according to the present invention thus provides a complete thermomanagement of the high voltage traction battery of a high performance rechargeable hybrid vehicle. Furthermore, it allows the battery to be installed close to the exhaust line while immunizing it if necessary, the temperature of the exhaust line being able, on the contrary, to help accelerate the rise in temperature of the exhaust system. drums. The method according to the present invention also makes it possible to have an optimized energy balance and without compromising on safety, dependability, battery durability and heat exchange performance, this at a negligible cost, both on the price of the battery only on the cost as a guarantee and after-sales.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood by means of the description, given below for purely explanatory purposes, of an embodiment of the invention, with reference to the figures in which: FIG. 1 illustrates the main life phases of the process according to the present invention; - Figure 2 represents the thermal states of the method according to the present invention; - Figure 3 illustrates the determination of thermal losses of the battery; FIG. 4 represents the determination of the set temperature required for the thermal regulation of the battery; - Figure 5 illustrates a correction of the thermal regulation of the battery in the context of a map; - Figure 6 shows the state "Non-use"; Figure 7 illustrates the post-cooling function of the battery; and - Figure 8 shows the "fault management" state of the method according to the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

As a reference, computers in the vehicle and / or GMP perimeter already exist to manage the air-conditioning system: control of the air-conditioning compressor, the GMV and the on / off control valves of the cabin and battery refrigeration branches, regulation of the thermal system cockpit between heating and refrigeration. The principle adopted here is then to communicate the actual temperature and the thermoregulation setpoint of the battery to these computers, as if they were an additional need for them to satisfy, this instruction being elaborated either entirely in the computer battery, either entirely in the coordination computer of the hybrid powertrain (GMPH) (purely thermal mode management, purely electric and hybrid), or by parts in these two computers. The prioritization between the refrigeration of the battery and that of the passenger compartment is managed the computer having already in charge of the air conditioning function, in particular via the on / off control of the cockpit and battery loops and the rotational speed of the compressor. In particular, the control of these on / off valves makes it possible to overcome the risk of icing of the cabin and battery evaporators, allows the deactivation of one of the two refrigeration loops (cockpit or battery) when there is no it does not need and finally avoids the risk of accumulation of the lubricating oil of the compressor in the refrigeration loop of the battery when the latter is inactive.

The commonly accepted criterion for the design of the cooling of a high-voltage traction battery for application to a plug-in hybrid vehicle, in particular (but not only) Li-ion technology, is 40 ° C, with possible incursions as far as possible. at 45 ° C for more exceptional life situations and with an impact on the life of the battery, if the T ° battery "out of use" is not reduced to a lower level, the criterion sizing for the life of the battery being primarily its average T °. In addition, a criterion of maximum cell-to-cell gradient (called inter-cell gradient) applies, having to remain below 5 ° C between the coldest cell and the hottest cell of the battery pack. Finally, because of the architecture of the battery pack and the mode of cooling retained (cold cooling by cold plate by the lower base of the cells), this requirement is completed by a criterion of maximum gradient internally of the same cell (dit intra-cell gradient), which should also remain below 5 ° C. Indeed, the Li-ion technology is sensitive to the average T ° and T ° gradients: a heterogeneous cell cooling generates premature aging of the hottest cells, leading to a heterogeneity of performances between cells, accelerating the aging of the cells. the entire battery pack. The battery thus has sensors of T ° cells (on the surface or inside the cells) in adequate number.

Figure 1 illustrates the main life phases of the method according to the present invention, and in particular the transitions between the life phases "use", "out of use", "fault management" and "diagnosis".

As soon as the power-on request (DMST = 1) or the activation of the GMPH is activated, the function switches from an "out-of-use" state to the "use" state, the output of which is effected in the state " out of use "on the condition of DMST = 0 or GMPH inactive, either in the" Fault Management "state, described later, or in the" Diagnosis "state where the various logic tests and the tests of the actuators of the system. In the "out of use" state, when the system is idle, the thermomanagement strategy is very generally inactive. During the entire period when the 1 o battery is in this state of rest, its computer scans at regular intervals of time the T ° of the cells of the battery (at a periodicity and duration adequate according to the technology of the battery, for example every hour), both to estimate the aging of the battery and for security purposes. If the latter measure requires it (for example in case of excessive drift of the T ° of the cells beyond a certain safety threshold) and if the state of the battery and the different computers involved allow it, Active management of the battery can be activated in order to control the rise in temperature, including by waking partially or completely these computers. The life phase "use" of the battery is broken down into three main thermal states depending on the internal temperature of the battery: cold, warm and hot. Figure 2 shows the thermal states of the process according to the present invention. A first "initialization" state makes it possible to initiate the "utilization" state and in particular the acquisition of the temperature of the battery by the thermo-management system as well as the launching of the calculations, detailed below, necessary for the determination of the temperature set point of thermoregulation of the battery. Depending on the T ° values of the battery, the system switches to the "Cold battery" and then "Warm battery" and then "Hot battery" states, from one calculation step to another according to the effective T ° of the battery (By default, each calculation step takes place every 10 to 100 ms), ie the time that its T ° reaches and exceeds the thresholds of T ° associated with "T ° batt_froide" and "T ° batt chaud hot".

The various actions taken by the thermo-management system of the battery in the states "Cold Battery", "Warm Battery" and "Hot Battery" will be described later. The transition of each of these states to the "Fault Management" and "Out of Use" states is enabled by the occurrence of the associated initiating events; in particular, the disappearance of all faults allows the return to the initial thermal state according to the T ° then known by the 1 o battery.

In the "use" state, a first phase consists in determining the thermal losses of the battery. The strategy is thus self-adaptive. All the calculation steps described below will be assumed (unless explicitly stated otherwise) to be at the level of a unit cell. The calibration of the multiplicative factor "Nbre_cells" will, depending on the case and sometimes by language abuse, to move from the scale of the cell or module to that of the complete battery pack.

If the determination of the thermal losses of the battery (at the level of the unit cell, of a module or of the complete pack) is already carried out autonomously by the computer of the battery, then part of the function described here is not necessary since already accomplished. It is then only necessary to carry out a filter over time, according to the process defined below. The filter implemented can be of sliding average type over a window of appropriately selected width (20 to 60 seconds) improved by a low-pass filter or hysteresis, or preferably one or more first-order or second-order filters of which the time range is judiciously chosen (20 to 60 seconds), or any combination of at least two of these filters. Otherwise, and if the instantaneous internal resistance of a cell is not already known by its computation or extrapolation of a mapping by the computer of the battery, then a first table determines, as a function of the temperature of the cell considered. T ° cell_i, the SOC and the nature (in discharge or charge) and the duration (pulse time) of the solicitation of the battery, the instantaneous internal resistance in BOL of the cell, by direct reading and / or by interpolation within the same map or between at least two maps. The internal resistance of the battery in BOL is then obtained by performing the same operation for all the cells and summing on the number of cells. As this internal resistance increases with the aging or the damage of the battery, the extrapolation is corrected by a factor representative of the aging and the damage of the battery (= 1 in BOL and> 1 in EOL), either already present and used by the battery calculator for other functions (determination of the SOH), is indicated by a function

1 o dedicated hosted in the strategy of thermo-management. The function determining the damage factor uses, in particular, the battery temperature, the depth of discharge, the number of recharges from the external electrical network and the use made by the customer of the vehicle (driver typing, nature of the rolling, etc.). distance traveled, rolling distribution /

15 storage). The instantaneous thermal losses of the battery are then determined by Joule effect according to the formula Qbatt_i = (Rint_batt_BOL + Rcontact) x age_factor x (Ibatt) 2 in which:

2o - Rint_batt_BOL is the internal resistance at the beginning of life of the complete battery pack according to the following formula: Number _ cells R int_ batt _ BOL = R int_ cell _ i _ BOL l = 1

where Nbre_cells denotes, according to the information available at the level of the first table, the number of cells or modules of the battery (assuming them

25 associated in series). If the internal resistance values manipulated above are at the scale of the battery and not of its cells or of its constituent modules, then the factor Nbre_cells will be taken equal to 1. For example, for a battery consisting of 4 modules of 16 cells each, Nbre_cells can then be worth 64 or 4 or 1 according to the adopted point of view.

3o - Rcontact is an additional term designating a contact resistance, representative for example of the ohmic resistance of the internal wiring to the battery. This term can take a value: o zero if the contact resistance is already integrated in the internal resistance of the complete battery pack o or constant over the entire temperature field of the battery o or variable depending on the T ° and the SOC of the battery - Ageing_factor is the multiplicative term representative of the aging and the damage of the cells of the battery in use. For example, the internal resistance of the battery increases over time, which implies an increase in losses by Joule effect since the necessary current remains constant until the voltage limits are reached, as well as 1 o voltage variations. much more important. - Ibatt is the current effectively delivered by the battery and takes a positive or negative value depending on whether the battery is loaded (receives current) or discharged (provides current). The filtered thermal losses are determined from the evolution of the instantaneous thermal losses of the battery over a number of samples T. For example, in the case of a realized average of the sliding type, the new value of instantaneous thermal loss Qbatt_i is added to the calculation of the average and the oldest Qbatt_i in the number of samples allowing this calculation is subtracted, according to the formula: n Qbatt _ moy = - Qbatt Z j = n_z where T, mean window, is for example set at 30s. A low-pass type filter is then applied at the end of the sliding average calculation process in order to smooth the variations of Qbatt_i. In the case where other filters, as explained above, are used instead of the sliding average, implemented alone or in combination, the filtering process is executed in a conventional manner. Figure 3 illustrates the determination of thermal losses of the battery. The function of determining the thermal losses of the battery will be activated every 10 to 100 ms in the thermal states "cold battery", "warm battery" and "hot battery" and the transition from one of these thermal states to the next has no effect on the calculations of Qbatt_i and Qbatt_filtered. If necessary and relevant, for the T first Qbatt_i calculations, the values of Qbatt_i will be initialized to zero, then replaced progressively by the values of Qbatt_i calculated. When a fault is detected and the thermo-management system of the battery switches to the "Fault Management" state, the function is suspended and the last calculated values are retained. When the system returns to the "Use" state, the function is again requested and uses as input data the last values retained. When DMST = 0 or of passage 1 o of the system in the state "Not used", the values Qbatt_i and Qbatt_filtered are not memorized. The operation of the battery is optimal over a fixed range of its temperature, for example ranging from a low temperature of between 15 and 25 ° C, up to 40 ° C. Indeed, the current delivered by the battery is strongly limited by its temperature from below 15 ° C and up to -20 to -40 ° C in Li-ion, or even up to 0 ° C in Li -polymer, temperatures below which the battery is unavailable because no longer able to provide current. Below 15 to 25 ° C and in particular in order to maximize the availability of the ZEV mode and the services then offered for a low outside T °, below 10 ° C and up to 0 ° C, - 20 ° C or -10 ° C, a reheating function (preferably by additional electrical resistances in direct contact with the cells or implanted in the refrigerant or in contact with the internal heat exchanger, but also by operation of the refrigerant circuit heat pump, by adaptation of the charging profile from the domestic or public electricity grid via the charger, by Joule self-heating of the battery by adaptation of the discharge profile, by deliberate and temporary degradation of the efficiency of the power train via a increasing the load on electric motors and via the regenerative braking system, etc.) makes it possible to overcome two problems superimposed on cold: 3o Resistive temperatures increase as the temperature of the cell is low; - Available powers are lower by limiting the current delivered by each cell at these temperatures.

However, for purposes of degraded mode management and operational safety, the thermal power installed for reheating will preferably be lower than the cooling potential of the battery, so that in the event of failure of the heating device, it is possible to more than offsetting the calories generated by reheating by those absorbed by the refrigeration system of the battery.

The preference given to reheating by additional electrical resistances implanted in direct contact with the cells means that, in use, the electrical power consumed for heating the battery is done by soliciting the battery itself. This presents a second advantage (in addition to its effective heating): this additional discharge of current also contributes to the self-heating of the battery. The autonomy in ZEV is not reduced, even on the contrary: this consumption of electrical power by the battery to heat up and self-heat counterbalances the reduced performance of the battery that would have required starting the engine to provide the wheel torque required by the user if the battery was not warmed up.

Note that in the area of use that requires a reheating of the battery, the consequence is not an attack on the life of the battery or its reliability but a reduction in the power available in charge and discharge.

In the "Cold battery" state (with T ° batt_cold constant value set in the zone [-40 ° C; + 25 ° C]), the battery is not in its optimal operating temperature range and therefore a reheating, complementary to its self-heating generated by its use, is necessary regardless of the T ° batt <T ° batt_froide. In this state, no cooling of the battery is required; the determination of the filtered thermal losses is nevertheless undertaken according to the procedure explained above. On the contrary, it is required to heat it, by default to 100% of the installed thermal power (preferentially of electrical origin by electrical resistances in contact with the cells), until the average temperature of the battery reaches the threshold T ° cold beats beyond which the system switches to the "warm battery" state. It is assumed that the self-heating of the battery associated with its load and discharge load is sufficient to maintain it in the optimum operating range, until it becomes necessary to refrigerate it.

This value of 100% of order will be corrected by possible limitations for the diagnosis of the order: thus, the value actually applied is a maximum RCO that takes this into account. Indeed, if the diagnosis of the command can be done only if the range of variation of the command is between 2 min and max values, then the effective command is saturated by these values. Otherwise (if the diagnosis of the order can be made whatever its value), the order is actually applied without corrections.

In addition to the average beat, the inter- and intra-cell gradients explained above are also monitored in the "cold battery" state. To do this, the local temperatures at the cell level (distributed within and / or along the same cell and from one cell to the other of the pack) are therefore scrutinized by the thermo-management function. If either of these criteria is no longer met (or both at the same time) during the actual reheating of the battery by the electrical resistors controlled at a maximum RCO (eg 100% or a slightly lower control taking into account limitations for diagnostic purposes), with reference to the RCO controlling the electrical resistances heating the cells with the highest T ° will be reduced to a maximum RCO value ensuring compliance with both criteria at the same time.

The "warm battery" status corresponds to a transient thermal situation where T ° beats E [T ° batt_froide; T ° beat_high [(range T ° batt_froide defined previously; T ° batt_chaude e [27 ° C; 33 ° C]) and where the battery, with regard to the values of its T ° in this area, does not need anymore to be warmed (if necessary - because the battery is at a T ° such that its maximum performance is accessible and is no longer limited by its T ° too low) and not yet need to be cooled. Therefore the thermo-management function requires in this thermal state neither heating nor refrigeration of the battery. The determination of the filtered heat losses is nevertheless undertaken according to the procedure explained above.

In this state as well, the inter and intra-cell gradients explained above are also monitored, in addition to the average T °. Thus, in addition to the average temperature of the battery, the local temperatures at the cell level are thus in this state also scanned. In this thermal state, since the battery is neither heated nor refrigerated, the thermal gradients mentioned above are therefore only due to the self-heating of the cells involved. Thus, this thermal state should therefore see the lowest thermal gradients by AT, due to thermo-management, zero and therefore should not a priori need corrective action as mentioned above for heating the battery or more far for its refrigeration.

The following paragraph details the thermo-management of the battery in the state "hot battery" according to the nominal strategy; will then be explained the corrections implemented possibly. The controller switches to the state "Hot battery" as soon as T ° beats reaches or exceeds T ° hot beacon. In this state, the function uses a table search with the input, the value of the thermal losses Qbatt_filtered battery and output a variable T ° cons_i representing an instantaneous temperature set temperature regulation of the battery. This variable T ° cons_i is compared to the variable 25 representing the temperature of the battery. As long as T ° batt is lower than T ° cons_i, the set temperature required for the thermal regulation of the battery T ° batt_req is equal to the constant T ° cons_maxi and then the effective refrigeration of the battery is not yet required since T ° batt is not yet high enough. As soon as T ° batt reaches or exceeds 30 T ° cons_i, the system sets the target temperature T ° batt_req required for the thermal regulation of the battery at the T ° instant set T ° cons_i. Figure 4 shows the determination of the desired temperature T ° batt_req required for the thermal regulation of the battery.

By way of example, the table T ° cons_i = f (Qbatt_filtered) rests on 4 points calibrable support (values below indicated for information and by way of illustrative and not limiting example): - T ° cons_i_min: minimum value taken by the instruction T ° cons_i: 28 ° C to 30 ° C - T ° cons_i_max: maximum value taken by the instruction T ° cons_i 35 ° C - Qbatt_filtré_min: minimum value saturated by the Qbatt_filtré: 400W - Qbatt_filtré_max: minimum value saturated by the Qbatt_filtered: 800W The filtration of the Qbatt on a fairly wide window (typical value: 30s) contributes to strongly smooth the evolutions of Tbatt_req: therefore, this strategy does not implement additional hysteresis. However, if a hysteresis is used by the control unit managing the air conditioning to guarantee the stability of the regulation and the functioning of the refrigeration loop, this hysteresis must not be too high so as not to have too much impact on the electrical consumption related to the cooling the battery. A hysteresis of 2 to 3 ° C on the T ° batt seems a good compromise between these 2 aspects.

When a fault is detected, the system switches to the "Fault management" state: this operation is suspended and the value T ° cons_i is retained. At the disappearance of all the defects, the function is again solicited and uses in data of entries, the last conserved values.

T ° batt having been able to evolve, a new value of T ° batt_req is calculated. In case of transition to the "Out of use" state, the values T ° cons_i and T ° batt_req are not memorized.

In order to establish the setpoint finally applied, the variable T ° batt_req will be corrected according to the following three processes detailed below: taking into account - criteria of thermal gradients inter- and intra-cell; - the ambient temperature under the box in the area where the battery is installed above the exhaust line; - the damage factor explained above.

In addition to the average T ° beat, the inter and intra-cell thermal gradients are also monitored in the "hot battery" state, as in the other thermal states of the battery (cold and warm). To do this, in addition to the average temperature of the battery, the local temperatures at the level of the cells (distributed within and / or along the same cell and from one cell to another of the pack) are therefore scanned by the thermomanagement function. If one or other of these criteria (or both at the same time) is no longer respected during the cooling of the battery according to the strategy 1 o nominal explained above and if at the same time, a margin exists on the average T ° beat compared to the criterion of 40 ° C, two strategies are possible. A first approach is to reduce or even stop the cooling of the battery to reduce or cancel these thermal gradients. Beyond an average T ° beat of 38 ° C (with a margin reduced compared to the criterion of 40 ° C), this approach will preferably be inhibited (and therefore the cooling of the battery maintained) to maintain the T ° average beat below 40 ° C at the expense of these thermal gradients, rather than maintained to favor the respect of these criteria of inter and intra-cell gradients at the expense of the average T ° beat; If the electrical resistances in contact with the cells are present and controllable (in particular with respect to the criterion of 40 ° C.), either independently of one another or in groups according to their implantation along the cells, a second approach consists, depending on the nature of the unmet thermal gradient: 25 - If it is the internal thermal gradient cell that is no longer respected, to warm locally the areas of the cells closest to their base in contact with the evaporator all maintaining or reducing the cooling capacity implemented by the refrigeration circuit, this in order to reduce the temperature difference between the base 30 of the cell in contact with the evaporator (thus cold) and the rest of the cell, by heating it one by one or by group of electric heaters - If it is the cell-to-cell thermal gradient that is no longer respected, warming the coldest cells n maintaining or reducing the cooling capacity implemented by the refrigeration circuit, in order to homogenize the temperature of the cells of the battery pack. From a perspective of energy balance and dependability, the first approach is favored compared to the second. However, and with reference, the internal exchanger (evaporator in the context of refrigeration of the high-voltage traction battery) will be designed so as to have the least possible use of this strategy.

1 o Given the installation of the traction battery outside the vehicle, under the body and in proximity with the exhaust line, and despite the installation of insulators and heat shields, the battery must be isolated from the resulting heat radiation. If it is not possible to totally isolate the battery from the additional thermal flux generated by the undercounter thermal environment (exhaust, external T °, ...), the thermo-thermal system of the battery must be able to take it account to inhibit the effects on the thermal cells of the battery. Thus, a specific strategy based on maps or a calculation model coupling the thermal and aaulic underbody and taking into account in particular the external T ° 20, the vehicle speed, operating parameters of the internal combustion engine,. .. is included in the thermo-management strategy of the battery and determines, in addition to the cooling and post-cooling strategies, the relevance of correcting the thermal regulation regulation of the battery in case of thermal radiation from the exhaust 25 important and / or dissipation under sufficient funds. On the other hand, when the battery is cold, this heat radiation of the exhaust contributes, when running in hybrid mode (heat engine with fire), to warm up the battery a little bit.

The input data of such maps or of such a calculation model are: the speed of the vehicle, the outside air temperature, the gas measured or estimated by calculation, accessible in the multi-function computer of the engine thermal, as close as possible to the location of the battery or to build from the regime, the motor load, the flag indicating the ongoing realization of a regeneration of the FAP and dissipation along and through the exhaust line and its various constituents (catalyst, ...) - the gas flow (if available, otherwise to build from the engine speed and torque) In the case of a calculation model, are also taken into account. consider the 1 o convective exchange coefficients between the various media (battery, exhaust line, ambient air, heat shield, insulation, ground), the associated exchange surfaces, the thermal conductivities of the materials and media used, Emissivities and the thicknesses of the components, as well as the distances between the different constituents. Figure 5 describes this correction in the context of using maps. These constituents are to be adapted according to the actual location of implantation of the battery on the exhaust line; Thus, the term FAP below may in fact designate, in certain cases, an oxidation catalyst and the associated correction take into account the generated exotherm, in the case where the heat engine is not equipped with it or whatever its energy (gasoline, diesel, LPG, ...).

The thermal power released or radiated by the exhaust line is estimated from the flow and temperature of the exhaust gas and the presence or absence of a regeneration of the FAP. In particular, rather than the simple product of the flow rate by the difference of T °, the first mapping makes it possible to deal with the case of low or zero gas flow rates with nevertheless a large radiated thermal flux generated by relaxation in 30 heat stroke when the engine thermal has just been cut (thus zero gas flow) after a strong stress. This mapping thus makes it possible to discriminate these life cases from others having the same flow conditions but with a really low clear thermal flux, discrimination that the simple product of the flow of gases by their T ° does not allow. On the other hand (according to its availability and its format), the associated flow "flag_RG_FAP" could be a boolean which will force the taking into account of a constant thermal flow associated with the regeneration of the FAP, for example of the type Pth_exhaust = Pth_exhaust_hors_FAP + Flag_RG_FAP x Flux_RG_FAP. The thermal power released by the exhaust line thus estimated enters, with the vehicle speed (image of the exhaust thermal power), at the input of a second map that outputs the setpoint temperature Tcbatt_req corrected. The instruction actually sent to the vehicle control unit managing the air conditioning system, for the thermo-management of the battery (CONS_TEMP_BTRAC), is then the minimum setpoint between that determined by the process above and that determined above.

The third process of correction of the thermoregulation setpoint finally applied takes into account the damage factor, which occurs again in the thermal regulation process of the high-voltage traction battery. In this way, the regulation temperature of the battery cooling is set to optimize the compromise between the durability of the battery and the performance and performance of the vehicle such as fuel consumption, autonomy and thermal comfort in the cockpit. This process determines a fictitious "slope" of damage to the high-voltage traction battery, depending on the age of the battery or the mileage of the vehicle. The optimization, adjusted throughout the life of the vehicle, consists, for example a customer overall low severity, to further exploit the battery (eg usable energy increased by a greater depth of discharge) to improve vehicle performance. For example: - For a maximum depth of discharge despite damage to the battery below the target, under the dummy slope: a high regulation temperature is allowed as long as the target wear rate of the battery is not reached; - For a minimum depth of discharge despite damage to the battery above the target, above the dummy slope: a lower battery regulation temperature is sought to preserve the battery; - For an intermediate discharge depth between the minimum and maximum levels and damage to the battery close to the target slope: the regulation temperature of the battery will preferably be decreased in order to increase the rate of wear of the battery or to increase the useful energy to iso-damage.

The thermoregulation instruction finally applied performs the synthesis between these three processes and the nominal process of thermal regulation, for example by applying the minimum value.

The sizing criterion for the life of the battery is primarily its average temperature. The battery T ° is managed in use phase, 15 in order to maintain it in its optimal operating range: such management has been explained above. But special attention must also be paid to the T ° battery "out of use", justifying thermomanagement in this case: parking, garage, parking, etc., this life situation can represent up to 80 to 85% of the duration of vehicle life. The "use" state has been detailed in the preceding pages. The following details the state "out of use" and in particular Figure 6. The transition to the state "Non-use" is done by an "initialization" step including dedicated to the identification of the associated life situation, among : battery charging - or after-cooling the battery - or thermal preconditioning of the battery - or battery rest. The transition to the "Rest" life situation is made in the absence of any other request (battery charging or post-cooling or thermal preconditioning), whether the charging cord is connected or not and as long as it is not There is no request for power on (DMST = 0) or activation of the GMPH. The output of the "Rest" life situation is done at the "initialization" stage as soon as a power-up request (DMST = 1) appears (in which case the system leaves the "out of use" state) or activation of the GMPH or the appearance of a request for recharging or post-cooling or preconditioning, regardless of whether the charging cord is plugged in or not (plug-in: respectively true or false).

Depending on the life situation in which the battery is actually located, the system is positioned in the associated configuration and performs the appropriate actions 1 o which will be described below. When the life situation in question is no longer verified (end of recharging or post-cooling or thermal preconditioning of the battery), the heat management system returns to the "initialization" stage from where, according to the whether or not a new life situation appears in the "out-of-use" state (ex: thermal preconditioning of the battery after recharging or recharging after a post-cooling), the system is positioned in the associated life situation or exits the "Out of use" state to take one of the states described above or otherwise the "Rest" state.

The output of each of the life situations, including the "initialization" step, is immediate as soon as a fault appears: the system then positions itself in the "fault management" state which will be described later. . At the disappearance of all the defects, the return to the "Non-use" state is done by the "initialization" step where the present life situation 25 and the appropriate associated state are again evaluated.

Each of the life situations mentioned above (rest, post-cooling, recharging, thermal preconditioning) will be described in the following paragraphs. In the "idle" life situation, the battery computer examines the cell temperatures for safety purposes (thermal runaway, etc.) and for estimating the aging of the battery. This monitoring takes place for all phases of life excluding the use of the battery: recharging, thermal preconditioning, post-cooling, rest, and in particular (but not only) while the vehicle is connected to the domestic or public electrical network. The periodicity and the duration of such a monitoring must be adapted to the type of Li-ion technology: for example, the computer of the battery wakes up hourly for a duration of at most 500ms to 1s to measure in particular cell temperatures and measure the SOH. The value of the temperature of the battery is then updated by averaging between the value at time t and the value at t-1 h and if the sleep phase lasts less than one hour, the battery calculator 1 o averages between "key off" and "key on" temperatures.

During this phase, it may be necessary for the heat management system to cool the battery if its temperature reaches a certain safety threshold and until the battery temperature drops below this threshold reduced by a certain hysteresis. When the vehicle is not connected to the domestic or public external electrical mains, the only source of electrical power to power the compressor to cool the battery is the battery itself, which may no longer be available if it is damaged or if its contactors are open. At the immediate end (initiating condition: DMST goes from 1 to 0, that is to say transition from "key on" to "key off" or active GMPH to inactive) of a thermal cycling for the battery , if its T ° reaches or exceeds a threshold of TEMP_BTRAC_POSTREFR_HIGH fixed for example at 38 ° C: 25 - high enough not to interfere with the strategies explained above in the context of thermo-management in the state "hot battery" - But low enough not to alter the life of the battery post-cooling is operated until the T ° of the battery 30 drops below a threshold TEMP BTRAC POSTREFR LOW set at eg 30 ° C.

By high or even temperate outside temperatures, this post-cooling is conceived and it is relevant to lower the temperature of the battery. On the other hand, at lower external temperatures, where it is known that the performance of the battery is reduced, in the absence of any device for heating the battery other than its self-heating in use or in order to save power electrical heating, it may be relevant not to post-cool the battery under these conditions so that the battery is stored in a cooler thermal environment, to keep inside the battery pack the heat useful for the next departure of the vehicle with a battery still in temperature, as much as possible to provide its nominal performance. 1 o Thus, under the condition stated above on the battery T °, is added as input condition in the post-cooling phase of the battery, a condition on the outer T °, such as the post -cooling is inhibited if the external T ° is below a threshold TEMP_EXT POSTREFR (for example 10 ° C). In this post-cooling life situation, it should be recalled that the vehicle is not connected to the domestic or public electrical sector (unlike the thermal preconditioning life phase, commented below): consequently, the energy as well devoted to post-cooling the battery 20 (primarily for the purpose of durability and availability of ZEV mode, and to a lesser extent for ZEV autonomy) can no longer be devoted to electric or hybrid mobility. A post-cooling value set too low is certainly favorable to the durability of the battery but this post-cooling is done by consuming electrical energy stored in the battery. Thus, the condition T ° batt TEMP_BTRAC_POSTREFR_LOW can be completed, in the first term of the term, a condition of maximum duration of post-cooling TIMER_POSTREFR (fixed at a value for example between 5 and 10 minutes). Figure 7 illustrates the post-cooling function of the battery. The purpose of the life phase "thermal preconditioning of the battery" is to take advantage of the connection of the vehicle to the external electrical sector (domestic or public) to warm or lower if necessary and judicious (depending on the outside temperature) the temperature of the battery: - as soon as it is connected to the external electricity network, at the earliest, for the purpose of battery life, thus lowering its average temperature or for the purposes of cold performance of the battery, by a reduced energy expenditure since the required energy is drawn from the power grid, whether or not there was post-cooling of the battery. - before departure of the customer (if the departure time has been programmed) by cooling or heating the battery so that it is in its optimal operating range T ° to guarantee an increased ZEV availability, depending on the value then taken by the temperature of the battery.

A thermal preconditioning in reheating of the battery is relevant, in order to satisfy a ZEV availability by cold outside temperatures, down to -5 ° C to -10 ° C. For the purpose of durability and availability of the battery and inter-performance with the refrigeration of the passenger compartment, for a departure ZEV in particular by warm external thermal ambient, for example up to + 30 ° C to + 40 ° C , it may be appropriate to refrigerate the battery if its T ° is too high before the customer's departure to allow it an increased ZEV availability. For higher or lower external T ° or if it is chosen to privilege the mobility of the vehicle by not devoting the residual energy stored in the battery to its thermo-management, it will be admitted the next time the vehicle is used , if the thermal battery does not allow a start in ZEV, the engine is started to ensure the mobility of the vehicle. During this time, the refrigeration or reheating of the battery (if any) will then be activated, in compromise with the refrigeration of the passenger compartment or with the electric power available according to the T ° batt, in order to allow as soon as possible the availability according to its T ° and the residual energy.

As a reference, this thermal preconditioning function is only accessible if the vehicle is connected via the charger to the domestic or public electricity grid, in order to reduce the associated energy expenditure and not to amputate the hybrid or electric mobility offered by the vehicle. electric energy stored in the battery, the interest being, in addition to the ZEV availability and battery durability already mentioned, to offer increased ZEV autonomy, since the refrigeration or the heating of the battery will not be active during the time that the battery will go up in T °. The associated electrical power is thus saved, while the battery is the sole source of electrical energy, or all the available cooling or heating capacity may be dedicated respectively to the refrigeration or the heating of the passenger compartment. without being amputated by the thermoregulation of the high voltage traction battery.

A request for thermal preconditioning of the battery is generated as soon as the charging cord is plugged in and: - in cooling mode, on TEMP BTRAC PRECOND HOT and EXT TEMP EXT PRECOND temperature conditions (for example 10 ° C) ; - in reheating, on a T ° beat condition <TEMP BTRAC PRECOND COLD (value between 10 and 25 ° C).

The conditions below include the entry into the thermal preconditioning mode of the battery: - state GMPH: not active - AND parking brake applied - AND condition gearbox: BVMP or BVA neutral or parking - AND source of available electrical power and in the specified acceptability criteria - AND no battery charging in progress - AND no body necessary for thermal preconditioning fails The output of the thermal preconditioning condition in cooling of the battery is on a threshold of T ° batt TEMP BTRAC _PRECOND_LOW (for example 15 ° C to 25 ° C) so that this value is: - sufficiently low to maximize the availability of ZEV rolling and for a cooling of the battery during the next run takes place as late as possible in order to maximize the autonomy in electric mode and prioritize if necessary the refrigeration of the cabin, - but still high enough that e the battery is in its range of optimal T ° vis-à-vis the electrical power deliverable.

The output of the thermal preconditioning condition in the heating of the battery is on a TEMP BTRAC PRECOND HIGH temperature threshold (value between 15 and 25 ° C and potentially different from TEMP BTRAC PRECOND LOW) so that this value either: - high enough for the battery to be in its optimal T ° range with respect to the electric power that can be delivered - but not too much not to have to cool the battery too early in order to maximize the autonomy in electric mode.

The "plug-in" vehicles, to offer the expected services (consumption breaking on mixed cycle and use, autonomy and availability ZEV), have the possibility of recharging the Li-ion battery on the sector (domestic or public outlet) ), either immediately upon connection of the charging cable and provided that all the necessary conditions are fulfilled, either in a deferred manner by programming eg the customer's departure time. In this situation of life also, the battery needs to be thermo-managed: - before recharging, cooling or heating, to put the battery thermally in condition to allow charging, for example if the recharge of the battery requires that its temperature belongs to a certain range and if a recharging said fast or slow to a power too high and a battery temperature too low (ex: from - 20 ° C to 0 ° C) or at a temperature too high ( eg:> 40 ° C) would be damaging to the battery; during recharging, in cooling (generation of calories by the Joule effect and as a consequence of the exothermic chemical reactions taking place therein), so as not only not to exceed the upper limits of T ° batt with respect to its reliability and its life, but also to optimize the duration of the recharge. Indeed: - for a T ° batt too high, the battery prohibits or suspends its recharge to protect itself; - For a T ° batt too low, the recharge can be adapted by limiting the power at the beginning of recharge to heat the battery and recharge it with the nominal power level, potentially increasing the overall recharge time; - but also after recharging, in cooling as in reheating, to ensure the availability of the battery for a taxi ZEV immediately after recharging if its internal temperature had 1 o of adventure too much or not enough increased in the end recharge.

In all cases, the heating or cooling of the high-voltage traction battery requires the operation of high voltage components (eg electric compressor, additional electrical resistors) or low voltage (example: solenoid valves, relays, GMV). Therefore, SOC high and low voltage batteries will be maintained; in the case of the low-voltage battery (service battery), it may even be to recharge to meet a threshold of runability of the combustion engine.

20 Before recharging, the thermo-management of the battery can be justified to put the battery thermally in condition to allow recharging, if this recharge requires that its temperature belongs to a certain range. If this is the case and if T ° beats TEMP BTRAC BEFORE HOT (eg 35 to 40 ° C), then cooling is performed until T ° beats <TEMP BTRAC RECH START HOT (for example 30 ° C), set at a compatible value of the T ° batt range mentioned above and such that a cooling of the battery during its charging is, as far as possible, no longer necessary, in order to optimize the charging time . Similarly, if appropriate (if the battery technology chosen requires it), if T ° beats TEMP BTRAC BEFORE COLD RECD (in a range of -40 ° C to 0 ° C), then a warming of the cells of the battery is operated until T ° batt TEMP_BTRAC_RECH_START_COLD (eg 0 to 25 ° C), set to a compatible value of the range T ° batt mentioned above and such that cooling or heating the battery during its recharge are, as far as possible, no longer necessary, in order to optimize the charging time.

During recharging and even during the cell balancing phase, the thermo-management of the battery can be justified to favor the recharge for the calories released by Joule effect and by the exothermic chemical reactions taking place there. If this is the case and if T ° beats TEMP BTRAC RECH DURING (for example 40 ° C), then a cooling is operated until T ° batt TEMP_BTRAC_RECH_LOW_DURING (for example 30 to 35 ° C), fixed values so that a second cooling phase of the battery during its recharging is, as far as possible, no longer necessary, in order to optimize the charging time.

The thermo-management of the battery can be justified also at the end of the recharging, to guarantee the availability of the battery for a taxi ZEV immediately following its recharging if the T ° of the battery is too high at the end recharging or in order to reduce the energy consumption due to the thermo-management of the battery during this rolling or to be able to devote all the cooling capacity or heat available to the refrigeration or heating of the cabin during this journey. If this is the case and if T ° beats TEMP_BTRAC_RECH_AFTER_HOT (for example 35 ° C) or if T ° beats TEMP_BTRAC_RECH_ AFTER _COLD (in a range of -40 ° C to 15 ° C), at the immediate end of the recharge, then respectively a cooling or a reheating is operated until T ° batt reaches TEMP_BTRAC_RECH_AFTER (in a range of 10 to 25 ° C), fixed so that this value is sufficiently low to maximize the availability of ZEV rolling and so that cooling of the battery during the next driving takes place as late as possible to maximize the autonomy in electric mode, but still high enough for the battery to be in its optimal range T ° vis-à-vis of the deliverable electric power.

As in the post-cooling phase (with the difference that the battery and the vehicle are not connected to an external energy source while this is the case here), by low ambient ambient temperatures such as that the performance of the battery chambered at these temperatures are reduced compared to their level at higher battery temperatures, the lack of cooling of the battery after recharging can be justified so, the battery then being stored in a thermal environment more cold, to keep inside the battery pack useful heat for the next departure of the vehicle with a battery still in temperature, as much as possible to 1 o provide its nominal performance. This strategy also aims to save the implementation of a reheating a posteriori to compensate for the cooling that would have been operated, and the electrical energy associated with these operations. Thus, on the condition stated above on T ° batt is added, as a condition of entering the cooling phase of the battery after recharging, a condition on the ambient T °, such as aftercooling. is inhibited if T ° ambient <TEMP EXT RECH (calibrated value, pre-calibrated at 10 ° C). In the case of a scheduled recharge, calculating the wakeup time of the computers used in this charging process will have to take into account the time required for thermo-management of the battery which will then have to be undertaken, taking into account that in particular the temperature of the traction battery and the outside temperature may have meanwhile changed. Preferably, in the case of an immediate recharge, but also in the case of a programmed recharge, according to the electric power 25 available from the domestic or public electrical network outside and depending on the need for thermoregulation of the battery, the thermocouple necessary management (cooling or reheating) can be done at the same time as the start of recharging.

Figure 8 shows the "defect management" state of the process according to the present invention.

As soon as a fault appears, the thermo-management system of the battery switches to the "Fault management" state where, depending on the nature of the fault, the system is positioned in the "Fault ..." state. partner and carries out the appropriate actions. If then a new fault appears, the system switches to the state "accumulated faults". The disappearance of all faults (in the state "accumulated faults") or the fault concerned (in the state "fault ...") allows, as explained above, the return to the original state then known by the thermo-management function of the battery before the appearance of the defect.

Among the defects that may be encountered by the thermo-thermal system of the traction battery include the following: a loss of temperature information, possible even if such batteries generally include several sensors T ° cells, the failure of the battery one of the sensors being able to be compensated by the information taken from the other sensors. Even if the occurrence of totally losing the information Tcbatt seems very low (breaking of electrical beams, ...), rather than putting the battery in unavailability (no longer supplying electricity) or to adopt a replacement value necessarily maximizing the cooling of the battery, the strategy described here provides for estimating the actual T ° beat from, in particular, the last known beat, the external ambient T °, the current transmitted or received by the battery, the SOC. , of the state GMP and vehicle (ZEV, hybrid), known parameters (for example by integrated modeling) of the refrigeration of the battery (if necessary: enthalpy at the input of the battery evaporator, pressure at the input and at the output of the battery evaporator according to the setting of the expander of the battery evaporator), of the original state then known by the thermo-management function before the appearance of the defect, and to use this input calculation of the strategies es previously explained. - Failure (failure, seizure, control beam breakage, glue relay) of the battery refrigeration actuators: electric compressor, on / off valves, GMV, shutters for obstructing the air inlets. The diagnosis of these actuators is required by the function, as well as the return, on the part of the computer managing the air conditioning, that the setpoint issued by the function has been taken into account and applied. In this case and with this information, the coordination system of the GMP may, depending on the evolution of the temperature of the battery, reduce the load (so that it releases fewer calories and thus reduce the need for cooling ) and restart the engine (if previously in all-electric driving) to thus ensure all or part of the motor power by this engine. - A failure of the heating elements of the battery. The diagnosis of these organs is required by the function, as well as the return that the instruction issued by the function has been taken into account and applied. An inability to warm the battery results in a loss of performance (electric power available to the battery, reduced compared to the nominal level). On the other hand, an unwanted permanent heating, potentially more serious for the reliability and durability of the battery, can be counteracted by the refrigeration system, provided that the cooling power is then greater than the sum of the heating power generated. by the heating system and the thermal power generated by the Joule effect within the cells. To achieve this, the heating power installed is by design less than that which can be implemented by the refrigeration system when priority is given, as is the case when such a failure is detected, the refrigeration of the battery compared to that of the cabin and on the other hand, it may be required that the coordination system of the GMP, as a function of the evolution of the temperature of the battery, reduce the load (so that it releases less calories and thus reduce the need for cooling) and restart the engine (if previously in all-electric driving) to ensure all or part of the motor by this engine. - Insufficient or no electric power to ensure the refrigeration of the battery (via the activation of the electric compressor) results in an abnormal rise in the temperature of the battery. By default it electronically reduces its performance from a certain threshold (eg if T ° batt> 50 ° C) before making itself unavailable (eg if T ° batt> 60 ° C). Without waiting to get to this point, the function detects it (via diagnostics and feedback, from the computer managing the air conditioning, the state of the refrigeration of the battery) and requires if necessary and according to the evolution the temperature of the battery, that the solicitation of the battery is reduced or canceled by including the restart of the engine to thereby ensure all or part of the motor skills of the vehicle. - Excessive cooling of the battery will be thwarted by the closed-loop strategy on the actual T ° of the battery, thus making the device self-adaptive. Thus if the T ° batt falls below a value between 25 to 30 ° C, the function requires the stopping of refrigeration of the battery. - A failure (leakage, clogging, ...) of the cooling elements of the battery: evaporator, expander. Either it results in an excessive cooling, and we find the case of the preceding paragraph, either the resulting cooling is insufficient or absent, and we find the conditions of the penultimate paragraph above.

Even if the refrigeration of the battery is more favorable to the acoustic problems than other thermoregulation devices (eg ventilation by the passenger compartment air), the transmission of noise or vibrations under thermo-management the battery does not remain to monitor: - noise of GMV, especially running ZEV if a need for 20 refrigeration of the battery is necessary: a control of the GMV continuously variable speed and ideally via a brushless motor , allows to get rid of this problem. acoustic constraints in the post-cooling phase, thermal preconditioning or battery charging, associated mainly with the GMV switching in small rotational speed, while the vehicle is parked or in the garage of the user's home. - Compressor noises and actuation of on / off valves (eg thrust-to-stop noises) - Switching and control noises 30 - Vibration transmission on bushings and body mountings or on parts in contact.

The invention is described in the foregoing by way of example. It is understood that the skilled person is able to realize different variants of the invention without departing from the scope of the patent.

Claims (10)

REVENDICATIONS1. A method of refrigerant fluid thermal regulation of a high voltage traction battery of a hybrid vehicle, said battery comprising a plurality of cells, characterized in that it comprises: a step of determining a life phase of said battery among a plurality of phases of life; a step of determining a thermal state of said battery among a plurality of thermal states, as a function of the temperature 1 o of said battery; and a step of adjusting the temperature of said battery as a function of said determined life phase and said thermal state, as a function of thermal gradients within and between cells, as a function of the environmental temperature of the battery and depending on its damage. 2. Method according to claim 1, characterized in that said life phases are selected from the following group: "Use", "Fault Management", "Non-use" and "Diagnosis". 3. Method according to claim 1 or 2, characterized in that said thermal states are chosen from the following group: "cold battery", "warm battery" and "hot battery". 25 4. Method according to one of the preceding claims, characterized in that the temperature of said battery is measured every 10 to 100 ms to determine the thermal state of said battery. 5. Method according to one of the preceding claims, characterized in that it further comprises a step of determining the thermal losses of said battery. 20 6. Method according to the preceding claim, characterized in that the determination of thermal losses of said battery is activated every 10 to 100 ms. 7. Method according to the preceding claim, characterized in that said battery is heated by implanted electrical resistances in direct contact with said cells of the battery. 8. Battery assembly for carrying out the method according to one of claims 1 to 7. 9. A battery pack according to claim 8, characterized in that it is implanted under the body of a vehicle and in proximity with the exhaust line of said vehicle. 10. Hybrid vehicle having a battery pack according to claim 8 or 9.