MOTOR VEHICLE FEATURING A POWER DISSIPATION DEVICE TO ASSIST BRAKING

Abstract

The invention relates to a downhill energy regulation method for a hybrid or electric motor vehicle (1000) comprising a thermal management system (500) controlling a high-temperature cooling circuit (100) associated with a fuel cell (10), a passenger compartment heating circuit (110) associated with a passenger compartment air conditioning unit (30) comprising circulation flaps allowing the separation of two independent airflows, a very low-temperature cooling circuit (120) associated with an electrochemical traction energy storage unit (26), and a low-temperature cooling circuit (130) associated with an electric powertrain (40) powered by this storage unit (26), and controlling the dissipation of excess energy in a heat sink included in the very low-temperature cooling circuit (120) or the low-temperature circuit (130),by coupling the high-temperature cooling circuit (100) with a heat transfer fluid loop (110, 120, 130) and the passenger compartment air conditioning unit (30). Figure 15,

Description

Title of the invention: MOTOR VEHICLE COMPRISING A DISSIPATION DEVICE POWER TO ASSIST BRAKING

[0001] The invention relates to a method of energy regulation during the long descent phase of a hybrid or electric motor vehicle comprising at least one energy source from among a fuel cell or an electrochemical energy storage system, a thermal management system of the powertrain associated with this at least one energy source, at least one heat transfer fluid loop, and at least one cabin air conditioning unit comprising a plurality of air circulation flaps, and a cabin heating circuit, said vehicle comprising at least one low temperature cooling circuit of at least one electric powertrain supplied by an electrochemical energy storage system, and a very low temperature thermoregulation circuit of said electrochemical energy storage system.

[0002] The invention relates, in a first fuel cell variant, to the field of fuel cell electric vehicles (FCEVs) comprising at least one fuel cell (FC) and a battery, the thermal management of an FCEV type drivetrain, and the HVAC (heating, ventilating and air conditioning) cabin air conditioning unit of such a vehicle, hereinafter referred to as the HVAC cabin air conditioning unit.

[0003] The invention relates, in a second all-electric variant of a battery-powered vehicle, to the field of battery electric vehicles, also known as BEVs, comprising only at least one battery.

[0004] Vehicle speed control on long descents is a comfort function (minimizing pressure on the brake pedal during descent to maintain vehicle speed), a satisfaction function (canceling brake temperature alerts), and a total cost of ownership function for the user (reliability / durability of the friction braking system by reducing its use on descents). However, the friction braking system must be capable of stopping the vehicle in an emergency (for example, if regenerative braking is unavailable due to a fault or component failure).

[0005] Engine braking is a braking method by which a vehicle is slowed down by the resistance its engine offers to its operation. This technique is linked to piston engines, which then incur significant losses through pumping (fuel injection being cut off) and through friction of the mechanical parts of the chain traction. The term is also used for vehicles powered by electric motors when these operate as generators and recharge, for example, a battery of accumulators by regenerative braking.

[0006] Engine braking is an important measure for vehicles towing and / or transporting heavy loads on steep roads because it considerably reduces the vehicle's braking work on descents. Intensive use of the friction braking system on long, steep descents quickly (within minutes) reaches its limit of effectiveness due to excessive heating, or even leads to its destruction. Under the effect of temperature, the brake pads and drum linings can melt, while the brake fluid can vaporize. Very long descents are thus sometimes the site of accidents, for example, in Isère on the Laffrey ramp which ends in a curve.

[0007] A diesel powertrain generates significant braking power: for a given engine, up to 160 kW at 3500 rpm, approximately 100 kW at 2500 rpm, and up to 50 kW at 1500 rpm. A spark-ignition powertrain of equivalent engine power delivers approximately 100 kW less at 5500 rpm and less than 20 kW less at 2500 rpm.

[0008] The braking power of electric vehicles is significantly lower than that of vehicles with internal combustion engines. Electric vehicles, however, have highly efficient regenerative braking systems that can generate high braking performance, provided that the state of charge of the electrochemical energy storage device (HVB for "High Voltage Battery") is sufficiently low at the top of the descent to store all the energy accumulated during braking.

[0009] Over long distances downhill, and especially on steep gradients, the electrochemical energy storage system's state of charge can quickly reach 100%, inhibiting any opportunity for further energy storage. Therefore, the electrochemical energy storage system's recharging potential is limited when its state of charge reaches and exceeds a high value (to protect the storage system from overload and / or overvoltage), when its internal temperature is low, or when the electrical components of the powertrain are close to their thermal limits. In this case, the vehicle's friction braking system must dissipate the energy required to brake the vehicle on its own. At the maximum permissible gross vehicle weight, if the trailer brakes are limited, the vehicle's friction braking system will quickly overheat, leading to its destruction and thus the loss of the vehicle's braking function.

[0010] Electrified vehicles have measures implemented to dissipate excess energy on board the vehicle in order to enable regenerative braking and prolong its operation in the worst conditions, essentially by activating electrical consumers located mainly within the vehicle's thermal system: electric heaters (usually used to heat the passenger compartment and / or the electrochemical storage of drive and / or, in the first fuel cell variant, the fuel cell stack in cold ambient conditions), motor-fan assemblies, electric clutch of mechanically driven fans, heated rear window (used in winter to defrost the rear window of the vehicle) and heated mirrors, electric air conditioning compressor, deliberate degradation of the efficiencies of electric motors and their inverters.

[0011] In the case of a fuel cell vehicle, when operating at high power the fuel cell is only cooled by the radiator of its cooling circuit.

[0012] A fuel cell in a fuel cell electric vehicle (FCEV) has no intrinsic braking power. The FCEV thus has a significant deficit compared to a vehicle with a self-igniting or even spark-ignition engine, and can therefore only rely on regenerative braking and the storage of recovered energy in its onboard electrochemical energy storage system, which is itself much smaller in size, power, capacity, and energy than the electrochemical energy storage system of an equivalent battery electric vehicle.

[0013] All subsystems and components of the vehicle and its powertrain are used to dissipate excess electrical power: electric heaters (electrochemical storage of drive, fuel cell only in the first fuel cell variant, passenger compartment), deliberate degradation of the efficiency of the electric motor(s) and its inverter(s), the electric air conditioning compressor, the vehicle's thermal systems including the fan units and heat transfer circuits (including the one or those dedicated to cooling the fuel cell only in the first fuel cell variant), as well as the cooling water pump, and the electric air compressor of the fuel cell only in the first fuel cell variant.

[0014] The vehicle's operating conditions (ambient temperature, cabin temperature control, particularly in refrigeration mode, and of the HVB electrochemical traction energy storage system) reduce the power dissipation capacity of the vehicle's thermal systems, as these systems are then dedicated to regulating the cabin temperature, defrosting / demisting the cabin, and / or regulating the HVB electrochemical traction energy storage system, these functions sometimes having to be performed simultaneously. This results in minimal additional power dissipation. electrical power must then be guaranteed, in order to dissipate this excess power without harming, hindering or compromising the thermal regulations in progress elsewhere.

[0015] Also, solutions derived from the state of the art do not offer optimal functionality for the purpose of dissipating part of the excess electrical power as thermal power.

[0016] In the first embodiment relating to fuel cell electric vehicles (FCEVs), the electric air compressor is an auxiliary component of the fuel cell and a significant consumer of the energy produced by the fuel cell stack (up to 10% to 20% of the electrical power produced by the stack), responsible for 65% to 80% of the power losses between the cell stack and the fuel cell system. Under these conditions, the fuel cell is idling or deactivated, but its electric air compressor is activated, if possible at maximum power, to help dissipate the excess electrical power generated by the vehicle on a downhill slope. The air propelled by the compressor bypasses the stack completely (if deactivated) or almost completely (if idling).However, protecting the fuel cell's electric air compressor from excessive speed and compression ratio helps limit its electrical power consumption. Furthermore, under high compressor load, the turbine bypass (which is integrated into the electric compressor to recover energy from the fuel cell exhaust and reduce the compressor motor's electrical consumption) can be disabled to limit the radial load on the compressor bearings. Additionally, the operating conditions of the fuel cell's electric air compressor decrease as altitude (inlet pressure) and / or the compressor inlet air temperature increase.However, the need to dissipate the excess electrical power generated by the vehicle during descent increases with altitude, becoming more significant at higher altitudes, and the capacity to dissipate this excess electrical power decreases at higher ambient temperatures. These considerations limit the use of the fuel cell's electric air compressor as an electrical power dissipator.

[0017] The fuel cell thermal management system is also used to dissipate some of the excess electrical power as thermal power, for example by activating the fuel cell's electric water-cooling pump, its cooling system fan, and at least one electric heater in one of the vehicle's fluid loops at full power. However, it is essential that, whether the fuel cell is idling or switched off, its durability is not compromised by: - excessively high or low coolant temperatures at the inlet and / or outlet of the fuel cell, - and / or an excessively large temperature gradient between the inlet and outlet of the fuel cell coolant, - and / or an excessive flow of coolant within the fuel cell, - and / or excessive coolant pressure within the fuel cell, - and / or an internal moisture level of the battery outside the permissible limits, leading to irreversible deterioration and / or degradation, through excessive drying or humidification, of the assembly formed by the membrane and electrodes of each cell of the battery.

[0018] These conditions reduce the availability of the fuel cell thermal management system to dissipate part of the excess electrical power, as well as the thermal power that can be dissipated.

[0019] Finally, even at idle, the fuel cell adds a minimum electrical power to the electrical power generated by the vehicle; otherwise, the fuel cell must be shut down immediately. However, stop / start cycles of the fuel cell significantly reduce its durability and should therefore be avoided as much as possible. Minimal electrical power dissipation must therefore be ensured.

[0020] Also, the solutions derived from the state of the art do not offer optimal functionality for the purpose of dissipating part of the excess electrical power of the fuel cell as thermal power.

[0021] On the other hand, the heat release from a fuel cell is significant (almost all of the losses must be dissipated in its cooling system, whereas for a heat engine, they are distributed in almost equal parts between its exhaust and water + oil cooling systems) and it requires operating at a lower temperature (between 60°C and 80°C), which strongly impacts the design of its cooling system (surface area and thickness of the heat exchanger(s) cooling the fuel cell, heat transfer circuit, fan, air inlets and outlets).

[0022] The objective of the present invention is to remedy these drawbacks by proposing to develop a method for dissipating the excess electrical power generated by the vehicle and / or by one of its components such as the fuel cell in the case of a fuel cell vehicle.

[0023] In the first variant of FCEV fuel cell vehicles, a device allows the coupling of the circuit to be broken and re-established, according to the state of the art. fuel cell cooling with at least one vehicle heat transfer fluid loop.

[0024] The cabin HVAC system adopts an additional, dedicated operating mode, available independently of the other operating modes of the cabin HVAC system, which increases the electrical power dissipated by the vehicle's thermal systems. This operating mode also increases the cooling potential of the fuel cell in the first variant.

[0025] In the first fuel cell variant or the second all-electric variant, the electric heater of the electrochemical motor storage unit can be connected to either the low temperature or very low temperature circuits and offers the vehicle, and in particular the powertrain, an additional source of power dissipation without impacting the other components.

[0026] To achieve this objective, the invention proposes a method for energy regulation during the long descent phase of a hybrid or electric motor vehicle comprising at least one energy source from among a fuel cell or an electrochemical energy storage system, a thermal management system for the powertrain associated with this at least one energy source, at least one heat transfer fluid loop, and at least one cabin air conditioning unit comprising a plurality of air circulation flaps, and a cabin heating circuit, said vehicle comprising at least one low-temperature cooling circuit for at least one electric powertrain powered by an electrochemical energy storage system, and a very low-temperature thermoregulation circuit for said electrochemical energy storage system.

[0027] According to the invention, said passenger compartment air conditioning unit is arranged to allow the separation of two independent airflows, one for air conditioning the passenger compartment of said vehicle and the other for heat exchange with the environment outside said vehicle, and said thermal management system of said vehicle is arranged to, when said vehicle is in a long descent phase, control the dissipation of excess energy produced by said vehicle and / or said at least one energy source in at least one heat sink which is an element of said very low temperature cooling circuit or which is an element of said low temperature circuit, by coupling at least one heat transfer fluid loop of said vehicle with said passenger compartment air conditioning unit, and by coupling the heat sink which is an element of said very low temperature cooling circuit to said low temperature circuit,in an additional operating mode to increase the electrical power dissipated by the thermal systems of said vehicle and to increase the cooling potential of said at least one energy source.

[0028] Thanks to the invention, it is possible to quickly dissipate excess power produced by the vehicle and / or at least one energy source.

[0029] Advantageously, said thermal management system of said vehicle is arranged to, when said vehicle is in a long descent phase, control the dissipation of excess energy produced by said vehicle and / or said at least one energy source in at least one heat sink which is an element of said at least one heat transfer fluid loop, using said at least one heat sink differently from its nominal use, and using said low temperature cooling circuit to reject excess thermal energy out of the vehicle as required for passenger comfort.

[0030] Thus, in order to quickly dissipate excess power, the thermal components already present on the vehicle in the low temperature cooling circuit are used as energy dissipators, other than in their usual mode of use.

[0031] More particularly, said air circulation flaps of said at least one cabin air conditioning unit are directed to expel excess thermal energy from the vehicle as required for cabin comfort.

[0032] The maneuver is thus simple and quick.

[0033] More particularly, said vehicle is equipped with a high-temperature cooling circuit for cooling said at least one energy source, and said thermal management system of said vehicle is arranged to, when said vehicle is in a long descent phase, control the dissipation of excess energy produced by said vehicle and / or said at least one energy source in at least one heat sink consisting of an element of said high-temperature cooling circuit and / or said low-temperature cooling circuit, using said at least one heat sink differently from its nominal use, and orienting said air circulation flaps of said at least one cabin air conditioning unit to expel excess thermal energy from the vehicle as required for cabin comfort.

[0034] Thus, in order to quickly dissipate excess power, the thermal components already present on the vehicle in the high temperature cooling circuit and / or in the low temperature cooling circuit, and / or in the very low temperature cooling circuit, are used as energy dissipators, other than in their usual mode of use.

[0035] More specifically, said thermal management system is arranged to control the dissipation of excess energy produced by said vehicle and / or said at least one energy source in at least one heat sink constituted by an element of said high-temperature cooling circuit, by controlling at least one first circulation pump comprising said high-temperature cooling circuit temperature, or a second circulation pump included in said passenger compartment heating circuit, to manage the flow through an air heater included in said passenger compartment air conditioning unit, by controlling a first valve and a second valve included in said high-temperature cooling circuit, by controlling a first electric heater included in said vehicle passenger compartment heating circuit, by controlling a first motor-fan unit included in said high-temperature cooling circuit associated with a first radiator.

[0036] Thus, the flow through the air heater is managed optimally.

[0037] Advantageously, said thermal management system is arranged to control the dissipation of excess energy produced by said vehicle and / or said at least one energy source in at least one heat sink constituted by an element of said low-temperature cooling circuit, by controlling a third circulation pump and a fourth circulation pump and a third valve and / or a fourth valve comprising said low-temperature cooling circuit, by controlling a second electric heater of said electrochemical energy storage system comprising said low-temperature cooling circuit, by controlling a second motor-fan assembly comprising said low-temperature cooling circuit associated with a second radiator, by controlling said at least one electric powertrain, a DC / DC converter comprising said low-temperature cooling circuit,and a coolant / cabin refrigerant heat exchanger, which is part of said very low temperature cooling circuit.

[0038] Thus, the control of the pumps and valves of the low temperature circuit allows a rapid reaction to the observation of a need to dissipate excess power.

[0039] Advantageously, said thermal management system is arranged to control the dissipation of excess energy produced by said vehicle and / or said at least one energy source in at least one heat sink constituted by an element of said high-temperature cooling circuit, by controlling at least said first circulation pump comprising said high-temperature cooling circuit or said second circulation pump comprising said vehicle passenger compartment heating circuit to manage the flow through a heater comprising said passenger compartment air conditioning unit, by controlling said first valve and said second valve comprising said high-temperature cooling circuit, by controlling said third circulation pump and said fourth circulation pump and said third valve and / or said fourth valve comprising said low-temperature cooling circuit,an optional electric air conditioning compressor, an optional electric supercharging compressor for at least one of said energy sources, said first electric heater included in the circuit, vehicle passenger compartment heating, said second electric heater of said electrochemical motor storage, said first motor-fan group comprising said high temperature cooling circuit associated with a first radiator, said second motor-fan group comprising said low temperature cooling circuit associated with said second radiator, said at least one electric powertrain group, said DC / DC converter, said coolant / passenger compartment refrigerant exchanger.

[0040] Thus, the control of the pumps and valves of the high-temperature circuit also allows a rapid reaction to the observation of a need to dissipate excess power.

[0041] Advantageously, said vehicle passenger compartment heating circuit is replaced or supplemented by a very low temperature thermoregulation circuit of said electrochemical motor storage unit, under the action of said coolant / passenger compartment refrigerant exchanger.

[0042] This optimizes heat exchange in the vehicle.

[0043] Advantageously, said second electric heater is connected to said electrochemical motor storage, or to said low temperature cooling circuit, or to said very low temperature thermoregulation circuit, to provide said vehicle and / or to said at least one energy source an additional source of power dissipation without impacting other components.

[0044] Thus, the best use is made of all existing thermal components to dissipate excess power.

[0045] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig. 1] schematically illustrates a high-temperature cooling circuit of a fuel cell, driven by a first pump which propels a cooling fluid into it; - [Fig.2] schematically illustrates a low-temperature cooling circuit temperature of at least one electric powertrain, consisting of an electric machine, its inverter and a reducer, which converts the supplied electrical energy into mechanical energy to move the vehicle, or by a fuel cell in a first variant of a fuel cell vehicle, and / or by an electrochemical energy storage system, i.e. a high-voltage battery whose temperature is regulated by a very low-temperature cooling circuit comprising a liquid coolant / cabin refrigerant exchanger known as a chiller; [Fig.3] schematically illustrates a passenger compartment air conditioning unit advantageously implemented for each variant of the invention, comprising two separate ducts; [Fig.4] is a diagram that illustrates the activation of the power dissipation function during a downhill journey; [Fig.5] illustrates a configuration of the high-temperature cooling circuit of [Fig.1] suitable for a first arrangement, for the first fuel cell variant, with activation of a first heater, even without any need to heat and / or defrost / demist the passenger compartment; [Fig.6] illustrates a configuration suitable for a second arrangement, for the first fuel cell variant, where the thermal power generated by the first heater in the passenger compartment heating circuit is not admitted into the high-temperature cooling circuit of the fuel cell; [Fig.7] illustrates a third particularly advantageous arrangement of the first fuel cell variant or a second all-electric variant in a "full cold" operating mode, in case of a large demand for refrigeration of the air supplied to the passenger compartment and with at the same time a large need for dissipation of excess power; [Fig.8] illustrates a fourth arrangement of the first variant with fuel cell, which makes it possible to increase the dissipation of thermal power through an air heater by passing through it colder cooling air, taken downstream of the evaporator of the passenger compartment air conditioning unit; [Fig.9] illustrates a fifth arrangement of the first variant with fuel cell, with decoupling of the low temperature and very low temperature circuits, and the limitation of the thermoregulation setpoint of the electrochemical motor storage to 50°C; [Fig. 10] illustrates a sixth arrangement according to a variant of that of [Fig.9], with forcing the cooling of the electrochemical drive storage via the coolant / cabin coolant exchanger down to a temperature below 25 °C, and in which the electric heater of the electrochemical drive storage is disconnected from the very low temperature cooling circuit and connected to the low temperature cooling radiator; [Fig. 11] illustrates, in a first arrangement of the second variant of the all-electric vehicle, the heating circuit of the vehicle's passenger compartment; - [Fig. 12] illustrates, for the second all-electric variant, the low-temperature cooling circuit of at least one electric powertrain; - [Fig. 13] illustrates a second arrangement of the second all-electric variant, according to the configuration then taken by the cabin air conditioning unit in a "full cold" operating mode, similarly to [Fig.7]; - [Fig. 14] illustrates a third arrangement of the second variant to increase the dissipation of thermal power through the air heater by passing through it colder cooling air, taken from downstream of the evaporator; - [Fig. 15] illustrates a motor vehicle capable of implementing the process according to the invention, in the first fuel cell variant, comprising a thermal management system controlling a high temperature cooling circuit associated with a fuel cell, a passenger compartment heating circuit associated with a passenger compartment air conditioning unit, a very low temperature cooling circuit associated with an electrochemical traction storage unit, and a low temperature cooling circuit associated with at least one electric powertrain; - [Fig. 16] illustrates a motor vehicle capable of implementing the process according to the invention, in the second all-electric variant, comprising a thermal management system controlling a passenger compartment heating circuit associated with a passenger compartment air conditioning unit, a very low temperature cooling circuit associated with an electrochemical traction storage unit, and a low temperature cooling circuit associated with at least one electric powertrain.

[0046] The invention relates to a method of energy regulation during the long descent phase of a hybrid or electric motor vehicle 1000 comprising at least one energy source from a fuel cell 10 for a first variant of a fuel cell vehicle or a battery 26 for a second variant of an all-electric vehicle, a thermal management system 500 of the powertrain associated with this at least one energy source, and at least one cabin air conditioning unit 30 comprising a plurality of air circulation flaps, and a cabin heating circuit 110.

[0047] The method according to the invention addresses the need to dissipate, through the vehicle's thermal management systems and its equipment, the excess electrical power generated by the vehicle, particularly on long descents. In this proven case, an additional power dissipation source is required. is implemented to increase the electrical power that can be dissipated by the vehicle's thermal systems.

[0048] This additional power dissipation source is implemented by dedicating the heater core, when it is not needed because it is bypassed by air within the HVAC cabin air conditioning unit, to additional power dissipation. An airflow, originating from outside or from the passenger compartment or drawn from within the HVAC cabin air conditioning unit, passes through the heater core and is then discharged outside the HVAC cabin air conditioning unit and the passenger compartment, into the underbody or underhood environment.

[0049] The electric heater of the electrochemical energy storage unit is arranged in parallel with the passenger compartment refrigerant / cooling fluid exchanger, also called chiller, for cooling the electrochemical energy storage unit and the latter, whose very low temperature heat transfer circuit is controlled, i.e. connected to the low temperature cooling circuit or separated from the low temperature cooling circuit.

[0050] In the first variant where the motor vehicle 1000 is an electric vehicle of the FCEV type, the method according to the invention takes into account the need to dissipate as thermal power, by the thermal management systems of the FC fuel cell, the excess electrical power generated by the vehicle and / or by the fuel cell.

[0051] In this proven case, an additional power dissipation source is implemented to: - dissipate the minimum power generated by the fuel cell operating at idle, - increase the electrical power that can be dissipated by the vehicle's thermal systems, - compensate for the reduced availability of auxiliary components of the fuel cell; - increase the cooling potential of the fuel cell (in particular of its cell stack).

[0052] An additional device makes it possible to decouple the thermal management system of the fuel cell from at least one heat transfer fluid loop of the vehicle in order not to disturb the thermal regulation of the fuel cell and to impair its durability.

[0053] In order to increase regenerative braking capacity, the invention proposes a solution for limiting the temperature, state of charge, and voltage of the battery and presents a coupling device, during regenerative braking, of the fuel cell cooling circuit with at least one liquid loop The vehicle's heat transfer fluid and the cabin air conditioning system operate in a dedicated, additional mode (with the air heater) to increase the electrical power dissipated by the vehicle's thermal systems and enhance the fuel cell's cooling capacity. The electric heater for the electrochemical energy storage system can be connected to either low-temperature or very low-temperature circuits, providing the vehicle and / or its powertrain with an additional source of power dissipation without impacting other components.

[0054] The method manages the conditions for entering the dissipation mode of excess electrical power generated by the vehicle, as well as the associated actions to be carried out.

[0055] The method manages the conditions for entering the dissipation mode of excess electrical power generated by the vehicle and / or by the fuel cell in the first variant, as well as the associated actions to be carried out.

[0056] In the first variant, a valve is disposed within the cooling circuit of the fuel cell stack, on the branch containing the heat exchanger between, on the one hand, the coolant of the cell stack and, on the other hand, the coolant circulating in at least one of the other fluid loops of the vehicle; this valve makes it possible to inhibit, if necessary, the associated heat exchange in order not to disturb the thermal regulation of the stack and not to harm its durability.

[0057] The vehicle's HVAC unit 30 includes an additional air circuit, comprising a dedicated air intake and blower, which connects to the main circuit between the heater and the evaporator, downstream of the distribution flap. It also includes an air outlet outside the vehicle and a control flap for the air outlet, such that the distribution flap allows the air from the additional air circuit to pass through the heater or not. The outlet end of a first additional duct opens upstream of the heater via a dedicated, controlled flap. A second duct, located immediately downstream of the heater and with one end also controlled by a dedicated flap, opens into the environment under the hood or, preferably, under the body, in a low-pressure area to facilitate the sizing of the additional blower (pressure jump and required airflow).The air heater is then separated from the passenger compartment and made available to dissipate additional thermal power, thereby increasing the electrical power dissipated by the vehicle's thermal systems and increasing the vehicle's heat dissipation capacity.

[0058] In the first fuel cell variant, the air heater is available to dissipate additional power, enabling the minimum power to be dissipated generated by the fuel cell operating at idle, to increase the electrical power dissipated by the vehicle's thermal systems to compensate for a reduction in the availability of auxiliary fuel cell components without affecting their reliability and durability, and to increase the vehicle's heat dissipation capacity to cool the fuel cell.

[0059] Non-limiting examples of implementation of this disclosure are described below; other embodiments may naturally take various forms. Of course, various features illustrated and described with reference to one or more figures may be isolated, or combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described.

[0060] [Fig-1] to [Fig. 10] illustrate a cooling architecture implemented in the framework of the invention for the first variant with fuel cell, with three heat transfer circuits.

[0061] [Fig. 1] details the high-temperature cooling circuit 100 of a fuel cell 10, driven by a first pump 11 which propels a fuel cell coolant (in English “FC coolant”) of a different nature (for example glycol water of very low electrical conductivity) from the coolant used in the other circuits.

[0062] This high-temperature cooling circuit 100 also includes a high-temperature radiator 12 which is assisted by a first motor-fan assembly 13, as well as a bypass duct 14 arranged in parallel with the high-temperature radiator 12. A first valve 15 distributes the fuel cell coolant flow between the bypass duct 14 and the high-temperature radiator 12. Another branch 16 of the high-temperature circuit, arranged in parallel with the bypass duct 14 and the high-temperature radiator 12, carries a heat exchanger 17 between the fuel cell coolant and the coolant of another fluid loop 110 described later, and is controlled by a second valve 18 which inhibits or allows (totally or partially) the circulation of fuel cell coolant through the heat exchanger 17.

[0063] A first conduit 21 and a second conduit 22 emerge respectively from the fuel cell stack 19 (FC ​​stack) of the fuel cell 10 and the high-temperature radiator 12, terminating within a first degassing box 20. Various arrangements are possible; in particular, the first conduit 21 is advantageously located above ground, i.e., above the maximum level of fuel cell coolant in the first degassing box 20, while the second conduit 22 is advantageously located below ground, i.e., below the minimum level of fuel cell coolant in the The first degassing box 20 is used, although the alternative of a second overhead conduit 22 is also possible. This first degassing box 20 also advantageously integrates the functions of a deionizer and a particle filter (these functions can alternatively be separated). The return 2011 of the fuel cell coolant from the first degassing box 20 into the high-temperature circuit 100 takes place immediately upstream of the first pump 11 to ensure its pressurization.

[0064] [Fig-1] also illustrates the heating circuit 110 of the passenger compartment of vehicle 1000, which includes a second pump 23 which propels a glycol water type coolant through an air heater 24 (forming a heat exchanger between this coolant and the air entering the passenger compartment) upstream of which are arranged a first heater 25, for example of the electric type, activated in order to heat the passenger compartment in cold ambient conditions, assisting or not a heat pump (implemented by a particular configuration of the refrigerant circuit) not shown, and the heat exchanger 17.

[0065] Alternatively, the vehicle passenger compartment heating circuit 110 can be replaced or supplemented by a thermoregulation circuit 120, or very low temperature circuit, of an electrochemical energy storage unit 26 (HVB for "High Voltage Battery"), i.e., a high-voltage battery. In yet another alternative, this first heater 25 can be replaced by an air heater located in a passenger compartment air conditioning unit 30 or in an air duct opening into the vehicle passenger compartment; however, this variant does not allow the dissipation of heat by this air heater into the high-temperature cooling circuit 100 of the fuel cell 10, to heat the stack of cells 19 of the fuel cell or to dissipate excess power in this circuit as shown in [Fig. 5].

[0066] [Fig. 11] to [Fig. 14] illustrate a cooling architecture with three circuits Heat transfer fluids implemented within the framework of the invention for the second all-electric variant. The requirements for such a vehicle (vehicle performance, battery size in particular) are not the same as for a fuel cell vehicle according to the first variant.

[0067] [Fig. 11] illustrates, for the second all-electric variant, the heating circuit 110 of the vehicle's passenger compartment 1000, which includes a second pump 23 that propels a glycol-water type coolant through a heater 24 (forming a heat exchanger between this coolant and the air entering the passenger compartment) upstream of which is arranged a first heater 25, for example of the electric type, activated to heat the passenger compartment in cold ambient conditions, assisting or no, a heat pump (implemented by a particular configuration of the refrigerant circuit) is not shown.

[0068] Alternatively, the vehicle's passenger compartment heating circuit 110 can be replaced or supplemented by a thermoregulation circuit 120, or very low temperature circuit, of an electrochemical motor storage unit 26.

[0069] Alternatively, this first heater 25 can be replaced by an air heater located in a passenger compartment air conditioning unit 30 or in an air duct opening into the passenger compartment of the vehicle, without changing the scope of the invention.

[0070] For the first fuel cell variant, [Fig.2] illustrates a low temperature cooling circuit 130 of at least one electric powertrain 40, i.e. an assembly consisting of an electric machine, its inverter and a reducer (in English EDU “electric drive unit”), which converts the electrical energy supplied, or by a fuel cell 10 in the case of a fuel cell vehicle, and / or by an electrochemical motor energy storage 26 (in English HVB “high voltage battery”) i.e. a high voltage battery, into mechanical energy causing the vehicle 1000 to move.

[0071] This low-temperature cooling circuit 130 includes a third pump 27 which propels a coolant through a low-temperature radiator 28 assisted by a second fan motor assembly 29. This low-temperature cooling circuit 130 also ensures the thermoregulation of various components: - if it exists, the charge air cooler 31, cooled by a water-cooled charge air cooler (WCAC) of the supply air, depending on the case of the fuel cell 10 where this cooler 31 is required. The circulation of the coolant through the charge air cooler 31 WCAC is controlled by a third valve 32; - the electric motor and inverter of the intake air boosting device, including an electric air compressor, as appropriate, of the fuel cell 10; - in the case of a fuel cell vehicle, of the first direct current / direct current converter 36 (in English DC / DC: "direct current / direct current") of the fuel cell 10; - at least one second DC / DC converter 37; - at least partially, of the electrochemical energy storage unit 26: beyond a given stress on the electrochemical energy storage unit 26, and / or a given ambient temperature, this branch is dissociated by a fourth valve 38 of the low temperature circuit 130, and the thermoregulation of the electrochemical motor storage unit 26 is then ensured by a bypass of the refrigerant circuit (not shown in the figures) of the vehicle 1000 via a coolant / cabin refrigerant exchanger 41, called chiller, in which the coolant is driven by a fourth pump 42.

[0072] These latter components are advantageously, but not exclusively, arranged on branches of the circuit in parallel with each other.

[0073] The low temperature circuit 130 also carries a second heater 43, for example of the electric type.

[0074] A third conduit 44 and a fourth conduit 45 emerge respectively from the electrochemical motor storage unit 26 and the low temperature radiator 28 to enter a second degassing box 46 (both preferably above ground: above the maximum level of coolant in the second degassing box 46) from which the return 4627 of the coolant into the low temperature circuit 130 is carried out immediately upstream of the third pump 27 in order to ensure its pressurization.

[0075] The very low temperature cooling circuit 120 of the electrochemical drive storage unit 26 by the coolant / cabin refrigerant exchanger 41, more precisely coolant / refrigerant circuit fluid of the vehicle air conditioning system, called chiller, is illustrated in the lower part of [Fig.2].

[0076] [Fig. 12] illustrates, for the second all-electric variant, a low-temperature cooling circuit 130 of at least one electric drive unit 40, i.e., an assembly consisting of an electric machine, its inverter and a reducer (in English EDU “electric drive unit”), which converts the electrical energy supplied by an electrochemical motor storage unit 26, i.e., a high-voltage battery (in English HVB “high voltage battery”), into mechanical energy causing the vehicle 1000 to move.

[0077] This low-temperature cooling circuit 130 includes a third pump 27 which propels a coolant through a low-temperature radiator 28 assisted by a second fan motor assembly 29. This low-temperature cooling circuit 130 can also provide thermoregulation for various components, these components being preferably, but not exclusively, arranged on parallel branches of the circuit, in particular at least one second DC / DC converter 37, and, at least partially, the electrochemical energy storage unit 26: beyond a given load on the electrochemical energy storage unit 26 and / or a given ambient temperature, this branch is disconnected by a fourth valve 38 of the low temperature circuit 130, and the thermoregulation of the electrochemical storage of motor power 26 is then ensured by a bypass of the vehicle's refrigerant circuit via a coolant / cabin refrigerant exchanger 41, called chiller, in which the coolant is driven by a fourth pump 42.

[0078] The low temperature circuit 130 also carries a second heater 43, for example of the electric type.

[0079] A third conduit 44 and a fourth conduit 45 emerge from the electrochemical motor storage unit 26 and the low temperature radiator 28 to enter a second degassing box 46 (both preferably above ground: above the maximum level of coolant in the second degassing box 46) from which the return 4627 of the coolant into the low temperature circuit 130 is carried out immediately upstream of the third pump 27 in order to ensure its pressurization.

[0080] The very low temperature cooling circuit 120 of the electrochemical drive storage unit 26 by the coolant / cabin refrigerant exchanger 41, called chiller, is illustrated in the lower part of [Fig.2].

[0081] In certain particular modes, the low temperature cooling circuit 130 and the very low temperature cooling circuit 120 mentioned above can be assembled in the same fluid loop, depending on the configuration taken by the fourth valve 38, or, in other cases, separated from each other, for example when the coolant / cabin refrigerant exchanger 41 is used to cool the electrochemical drive storage unit 26.

[0082] [Fig.3] details a passenger compartment air conditioning unit 30 (HVAC) advantageously implemented for each variant of the invention. A recirculation flap 301, operated according to the vehicle's equipment manually by the vehicle occupants and / or automatically by the passenger compartment air quality control and regulation function, selects the composition of the air drawn in by a blower 302, either entirely from the passenger compartment 3010 (INT in the figure) or from outside 3030 (EXT in the figure), in this case, via an air filter 303 located upstream of the recirculation flap 301.

[0083] In a first configuration, an evaporator 304, which is part of the refrigerant circuit, is located downstream and immediately at the outlet of the blower 302, regardless of the operating mode of the passenger compartment air conditioning unit 30 and the refrigerant circuit. The air to be cooled then passes through the evaporator 304, even if the refrigeration is inactive or if this passage is not necessary (air pressure losses in the evaporator 304 impacting the electrical consumption of the blower 302 to overcome them).

[0084] Immediately downstream of the evaporator 304, a local or global lower part is provided with an exhaust duct 305 to carry away to the outside of the vehicle the condensate produced during the operation of the refrigeration (example: condensation on the evaporator of the moisture contained in the air drawn in from outside) so that it does not fall inside the passenger compartment and, for example, soil the carpet and / or generate a false alarm among the occupants, making them believe there is a leak in the heat transfer circuit or the refrigerant circuit.

[0085] A second distribution flap 306 allows the air from the evaporator 304 (whether the refrigeration circuit is active or not) to bypass or not a heater 24 (conventionally arranged to provide heating for the passenger compartment). Finally, a last series of distribution flaps 309, 310, 311 allows the air from the mixing chamber, at the outlet of the heat exchangers (evaporator 304, heater 24), to be directed towards the different targeted areas in the passenger compartment (windowed areas that may need defrosting / demisting, lower and / or upper parts of the passenger compartment).

[0086] The invention is based on an additional duct 312, which is disposed between an air intake 319 and the upstream side of the air heater 24, and is equipped with an additional blower 313, and makes the air passing through this additional duct 312 bypass the evaporator 304. The inlet end 319 of the additional duct 312 opens preferentially upstream of the recirculation flap 301, on the side of the outside air intake 3030 so as not to compete, in certain operating modes, with the refrigeration of the passenger compartment and not to increase the noise of the air intake by the two blowers 302 and 313, and downstream of the filter 303 so as not to introduce into the passenger compartment air conditioning unit 30 and the passenger compartment dust or impurities from outside. The outlet end of this additional duct 312 opens upstream of the air heater 24 and is controlled by a dedicated flap 314.

[0087] A second conduit 315, located immediately downstream of the air heater 24 and one end of which is also controlled by a dedicated flap 316, opens into the environment under the hood or preferably under the body, in a low-pressure area in order to promote the sizing of the additional blower 313 (pressure jump and air flow to be supplied).

[0088] The control of the passenger compartment air conditioning unit 30, and more specifically the bypassing of the evaporator 304, relies in particular on information relating to the degree of humidity present in the passenger compartment and more specifically at the level of the front windows of the vehicle (windshield and left and right side windows). The principle described above applies equally to a basic single-zone passenger compartment air conditioning unit 30 or to a so-called "dual-zone" type.

[0089] This particular arrangement is necessary because of the problem of excess power dissipation by the heater. Without this group of With the air conditioning system configured in this way, the power dissipation capacity would be too limited due to the resulting constraints on passenger cabin thermal comfort. This approach reconciles what are currently conflicting needs.

[0090] In the first fuel cell variant, this approach also makes it possible to reduce the occurrence of running the electric air compressor 350 of the fuel cell 10 beyond the actual need of the fuel cell 10.

[0091] [Fig.4] shows the activation of the power dissipation function during of a downhill journey. This figure is applicable to both fuel cell vehicles and all-electric battery vehicles. The thin dashed line represents the evolution of the road's gradient over time along this journey: it begins with a flat section (zero gradient), then the vehicle enters (at the first SI star on the thin dashed line) a long descent (always a negative gradient along this section). Consequently, the vehicle power required (thick solid line) to maintain a constant speed (at the driver's setpoint) is initially positive but relatively low while the vehicle is traveling on the flat, then becomes negative as soon as the vehicle begins the descent.

[0092] This required vehicle power is determined based on information transmitted by the coasting and speed control functions (target and actual speeds and vehicle acceleration, wheel rotation speeds, steering wheel angle, vehicle mass estimate obtained from trailer connection information, or others), the position, speed and brake pedal deflection by the driver, as well as various powers, or electrical powers of the fuel cell in the case of a fuel cell vehicle (net power supplied, minimum power to be dissipated at idle, maximum dissipateable power determined in particular according to the operating conditions of the electric air compressor of the fuel cell) or of the battery in the case of a fully electric battery vehicle.

[0093] The algorithm calculates a torque offset to compensate for a slope or a load on the wheel torque. The vehicle's acceleration is limited within a minimum / maximum range, taking into account the vehicle speed. An acceleration exceeding the maximum limit is then due either to a negative slope (downhill) or to a load lower than the nominal load. Conversely, an acceleration below the minimum limit is then due either to a positive slope (uphill) or to a load higher than the nominal load. The acceleration limit is then set as the controller's target.

[0094] The thin dashed line represents the temporal evolution of the state of charge (SoC) of the electrochemical traction energy storage unit 26: the state of charge is slightly decreasing as long as the vehicle is moving on a flat surface, whereas The electrochemical energy storage unit 26, assisted or not by the fuel cell, provides at least one electric drive unit (called "EDU" from the English "electric drive unit") with the power needed to move the vehicle, and the power from regenerative braking (thin continuous line) is then zero and the temperature of the friction braking system (thick mixed line) is constant and low (this system is not then being used).

[0095] As the vehicle enters the descent and continues downhill, the power from regenerative braking increases sharply and then remains positive (thin solid line): consequently, the state of charge of the electrochemical energy storage unit 26 increases (thin dashed line) until it reaches a state of charge close to, but lower than (second star S2), the maximum permissible state of charge of the electrochemical energy storage unit 26 (value between 85% and 97%); at the same time, the temperature of the friction braking system (thick dashed line) increases slightly. When the maximum permissible state of charge of the electrochemical energy storage unit 26 is reached, it can no longer be charged and its state of charge is maintained constant; the friction braking system then takes over to control the vehicle's speed, and its temperature increases more sharply.At a temperature close to, but lower than (third star S3) the maximum temperature (500°C to 600°C) accessible by the friction braking system, the power dissipation process is activated (lightning bolt S4 on the thick dotted line curve): until now unused (flat curve: zero power value to dissipate), this process requires a positive level of power to dissipate, which varies over time.

[0096] Thus, the activation of this process occurs when the following three conditions are met: - slope: the threshold can be set at strictly 0° angle or 0% slope, or at any value of downward angle or downward slope; - charge acceptance of the electrochemical motor storage unit 26: this manifests itself either by a high state of charge value as in the previous example, above a threshold (second star S2), or by a reduced charge acceptance of the electrochemical motor storage unit 26 due to its temperature (in order not to degrade it by high charging currents, and thus avoid any phenomenon such as "lithium plating", i.e. formation of metallic lithium around the anode during charging, formation of dendrites, or other, internal to the cells of the electrochemical motor storage unit 26). - and the temperature of the friction braking system, measured or calculated.

[0097] Alternatively, the power dissipation process is activated when the first two conditions are met only, without waiting for a temperature threshold of the braking system to be reached.

[0098] Upon activation, the power dissipation process evaluates in real time and continuously: - on the one hand, the total power to be dissipated, taking into account the ongoing dynamics of the vehicle (in particular according to the evolution of the speed); - but also, the total power that can be dissipated, from nominal operating conditions and in degraded operating mode of the potential heat sinks.

[0099] These heat sinks include, in particular, the electric air conditioning compressor, the electric heater located on the vehicle's passenger compartment heating circuit, the electric heater of the HVB storage unit, the heat transfer circuit pumps, the cooling fan units of the high temperature and low temperature / very low temperature circuits and the refrigerant circuit, the electrical machine(s), and all DC / DC converters or inverters.

[0100] The electric air conditioning compressor is not shown in the figures to avoid overloading them, nor is the refrigerant circuit to which the chiller 41 belongs, i.e., the passenger compartment refrigerant / cooling fluid heat exchanger (for the portion of the refrigerant flowing through it). The operation of the electric air conditioning compressor depends on the requirements for thermally conditioning the passenger compartment and / or the electrochemical traction energy storage unit 26 (either separately or both simultaneously) via the passenger compartment coolant / refrigerant heat exchanger 41, the thermal comfort or passenger compartment defrosting / demisting setpoint, the outside temperature, the relative humidity, the temperature of the electrochemical storage unit 26 and inter- and intra-cell temperature gradients, the current, and the integral of the current exchanged over time passing through the electrochemical traction energy storage unit 26.

[0101] The operation of the first heater 25, in particular an electric heater, located on the vehicle passenger compartment heating circuit 110 depends, on the one hand, on the flow rate and temperature of the coolant that passes through it, and on the other hand, on the availability of a potential for dissipating this thermal power.

[0102] Regarding the flow rate and temperature of the coolant passing through it, such a first heater 25 can usually dissipate its maximum rated power up to a given coolant temperature: for example, 50°C to 60°C, then this maximum dissipated power decreases steadily as the coolant temperature increases. It is therefore advisable to have a heat dissipation capacity equal to this power, in order to regulate the coolant temperature through this heater to a value that allows the dissipation of its maximum rated power.

[0103] A potential for dissipating this thermal power is available in particular, through the air heater 24 in the passenger compartment or to the outside air, depending on the configurations taken by the passenger compartment air conditioning unit 30, in particular according to [Fig.3], (the second pump 23 being active at full power as well as at a minimum the additional blower 313 of the passenger compartment air conditioning unit 30 according to the constraints of ventilation noise perceptible in the passenger compartment), and according to the temperature and air flow passing through the air heater 24 (according to the setpoint applied to the blower 302 and the additional blower 313 of the passenger compartment air conditioning unit 30).

[0104] In the first variant of the fuel cell according to [Fig.1], the availability of a potential for dissipation of this thermal power exists, through the heat exchanger 17 if the second valve 18 is open, in the cooling circuit 100 called high temperature of the fuel cell 10, which dissipates it to the outside air via the operation at maximum power of the first pump 11, via the position taken by the first valve 15 which allows the coolant of the fuel pump to pass through the high temperature radiator 12 at maximum flow rate, and via the operation at the maximum permissible power of the first motor-fan unit 13, subject to a limitation to a maximum threshold in particular due to noise and vibration nuisances.

[0105] The technology and operation of the electric heater 43 of the electrochemical motility storage unit 26 are analogous to those of the electric heater 25. The power dissipation potential is made possible by the connection of this second heater 43 between the low temperature cooling circuit 130 and the very low temperature cooling circuit 120.

[0106] In the first fuel cell variant, the heat transfer circuit pumps (first pump 11, second pump 23, third pump 27, fourth pump 42) are activated at full power in order to dissipate the maximum excess electrical power and ensure the cooling of components whose operation is intentionally degraded and inefficient.

[0107] For the second all-electric variant, the pumps (second pump 23, third pump 27, fourth pump 42) of the heat transfer circuits are activated at full power in order to dissipate the maximum of excess electrical power and ensure the cooling of the components whose operation is intentionally degraded and inefficient.

[0108] The cooling fan motor assemblies, referenced as first fan motor assembly 13 of the high temperature circuit, and second fan motor assembly 29 of the low temperature / very low temperature circuit, and of the refrigerant circuit (not shown) to contribute to / ensure the condensation of the refrigerant within the condenser (also not shown), are also activated at their powers maximum (in order to dissipate the maximum excess electrical power) permissible (taking into account the acoustic and vibrational constraints induced by their operation and their rotation speeds, relative to each other, taking into account their relative arrangements).

[0109] With regard to the electrical machine(s), their operation is intentionally made inefficient in order to dissipate the maximum electrical power, at the maximum of their thermal capability (maximum winding temperatures: winding insulation, coil heads; where applicable, magnets, or other) and the thermal dissipation potential of the low temperature circuit 130. Where applicable, if the vehicle 1000 was previously in two-wheel drive mode, in FWD (front wheel drive) or RWD (rear wheel drive) mode, the AWD four-wheel drive mode is engaged, in order to dissipate more electrical power.

[0110] It is possible to dissipate power at all DC / DC converters or inverters by increasing the switching frequency (transistors, diodes, IGBTs, MOSFETs). Switching losses are increased, therefore more power is dissipated. This deliberately inefficient operating mode depends on the internal temperature of the semiconductor and inductor components, transformers, capacitors, connectors, cables, busbars, and printed circuit boards, and on the temperature of the coolant flowing through these subsystems (converters, inverters) within the low-temperature cooling circuit 130.

[0111] In general, the electrical operation of all these heat sinks also depends on their supply voltage.

[0112] From the total power to be dissipated and taking into account the total power that can be dissipated through the previous heat sinks, the availability of a potential for dissipating this thermal power exists through and taking into account different configurations taken by the cabin air conditioning unit 30 and the high temperature 100, low temperature 130, very low temperature 120 heat transfer circuits, which will be described later, the power dissipation process then determines the power remaining to be dissipated through the other heat sinks.

[0113] And in particular in the first variant of the fuel cell, the power dissipation process then determines the power remaining to be dissipated by the fuel cell system and in particular by the electric air compressor of the fuel cell 10, via its electric motor and the inverter not detailed in the figures.

[0114] The power dissipation process determines the remaining power to be dissipated through the other heat sinks according to a hierarchy that is preferably established in this way in order to limit the use of this mode of operation which is demanding for these other heat sinks, especially for the fuel cell system in the first fuel cell variant.

[0115] Alternatively, arbitration can be carried out in parallel and by reallocating the effective power to be dissipated in proportion to the dissipable power.

[0116] Thus, if the power to be dissipated is less than or equal to the sum of the powers dissipated by each of the heat sinks listed above, then in the first variant of the fuel cell the fuel cell system 10 and in particular its electric compressor 35 is not stressed, and either an order is established between these heat sinks: the first at 100% of its dissipateable power, then the second at 100% and so on until the power to be dissipated is satisfied, or all the heat sinks are stressed up to their dissipateable power affected by the ratio between the sum of the dissipateable powers and the power to be dissipated.

[0117] Similarly, in the first variant of the fuel cell, if the power to be dissipated is greater than the sum of the powers dissipated by each of the previously listed heat sinks, then the fuel cell system is stressed: all the heat sinks are stressed up to their dissipated power.The fuel cell system determines its maximum current dissipated power, taking into account its operating conditions: outside temperature, altitude, axial load on the bearings of the electric motor of the compressor 35, internal temperatures of the electric motor and the compressor inverter, humidity level of the electrode-membrane assembly or MEA (from the English "membrane electrode assembly"), air temperature at the inlet of the fuel cell cell stack taking into account the operation of the charge air cooler 31 WCAC, water-cooled, cooling the fuel cell feed air 10, internal temperature of the cell stack, operating pressure (avoid compressor pumping), compressor rotation speed (avoid any overspeed), stoichiometry.And the fuel cell system (in particular, its controlled air loop, including the fuel cell's electric air compressor 10, the necessary valve on the intake air side and possibly the compressor turbine) is used to dissipate the additional power to be dissipated.

[0118] For the second all-electric variant, if the power to be dissipated is less than or equal to the sum of the powers dissipated by each of the heat sinks listed previously, then either an order is established between these heat sinks: the first at 100% of its dissipated power, then the second at 100%, and so on until the power to be dissipated is met, or all the heat sinks are used up to their dissipated power multiplied by the ratio between the sum of the dissipated powers and the power to be dissipated. If the power to be dissipated is greater than the sum of the powers dissipated by each of the heat sinks listed previously, then all the heat sinks are used up to their maximum power dissipation capacity and the following provisions are activated in order to increase the power dissipated by the heat sinks.

[0119] Another alternative, illustrated in [Fig.4], consists of identifying different power levels to be dissipated (for example, four levels Niv1, Niv2, Niv3, Niv4, as in [Fig.4]) and associating, with each of these levels, different strategies for dissipable power, for example at least one given heat sink for the first level, and the addition of at least one different heat sink for the second level and so on, or variable dissipation levels for at least one heat sink (example: inefficient operation of the electrical machine(s)).

[0120] In the first fuel cell variant, six arrangements presented below, which are not exhaustive, can be implemented in order to increase the power dissipated by the heat sinks and thus reduce the power to be dissipated by the fuel cell system (in absolute value and occurrences of power dissipation by the fuel cell).

[0121] [Fig.5] illustrates a configuration suitable for a first arrangement, for the first variant of fuel cell. The first heater 25 is activated, even outside of any need to heat and / or defrost / demist the passenger compartment, and is supplied with excess electrical power, which it transforms into thermal power, which the activation of the second pump 23 transports within the passenger compartment heating circuit through the air heater 24 and the exchanger 17 between the fuel cell coolant and the heating circuit coolant 110.The heat exchanger 17 transfers this heat from the heating circuit 110 to the high-temperature cooling circuit 100 of the fuel cell 10, which dissipates it to the outside air: the activation at its maximum power of the first pump 11 transfers this thermal power within the cell stack 19 of the fuel cell 10 and through the high-temperature radiator 12 where the activation of the first motor-fan group 13 transfers the heat to the outside ambient air.

[0122] [Fig.6] illustrates a configuration suitable for a second arrangement, for the first fuel cell variant. The thermal power generated by the first heater 25 in the passenger compartment heating circuit 110 is not admitted into the high-temperature cooling circuit 100 of the fuel cell 10. In this case, the second valve 18 is closed to inhibit heat transfer from the coolant of the heating circuit 110 through the heat exchanger 17 to the coolant of the fuel cell 10. The high-temperature cooling circuit 100 of the fuel cell 10 then adopts this configuration, as shown in [Fig. 6], in order to activate the first pump 11 at its maximum power, and the first fan assembly at its maximum permissible power (taking into account the induced acoustic and vibrational constraints). 13, without cooling the stack of cells 19 of the fuel cell which is then operational at idle or in standby or off, the high temperature radiator 12 being then bypassed by the fuel cell coolant.

[0123] In the first fuel cell variant in the second configuration of [Fig. 6], the excess electrical power, converted into thermal power by the first heater 25 of the then-active passenger compartment heating circuit 110, cannot be dissipated through the heat exchanger 17 into the high-temperature cooling circuit 100 of the fuel cell 10. It is possible, still in this configuration, given the conventional operating modes of a passenger compartment air conditioning unit according to the prior art, that it may not be possible to dissipate this thermal power through the heater if it is likely to degrade thermal comfort and / or the demisting / defrosting of the passenger compartment. In this case, this first heater 25 is deactivated, its current dissipative power is reduced to zero, and the powertrain loses an opportunity for power dissipation.

[0124] For the second all-electric variant, five provisions presented below, which are not exhaustive, can be implemented in order to increase the power dissipated by the heat sinks.

[0125] [Fig. 11] illustrates a configuration suitable for a first arrangement, for the second all-electric variant. The first heater 25 is activated, even without any need to heat and / or defrost / demist the passenger compartment, and is supplied with excess electrical power, which it transforms into thermal power, which the activation of the second pump 23 transports within the passenger compartment heating circuit through the air heater 24.

[0126] For the second all-electric variant, the excess electrical power, converted into thermal power by the first heater 25 then active in the passenger compartment heating circuit 110, may not be able to be dissipated through the air heater 24, given the conventional operating modes of a passenger compartment air conditioning unit according to the prior art, if it is likely to degrade thermal comfort and / or the demisting / defrosting of the passenger compartment. In this case, this first heater 25 is deactivated, its current dissipative power is reduced to zero, and the powertrain loses an opportunity for power dissipation.

[0127] In the first fuel cell variant in the second configuration illustrated in [Fig.6], the cabin air conditioning unit 30 according to the present invention adopts the operating mode illustrated according to a third arrangement in [Fig.7], while the cabin air conditioning unit 30 is in "full cold" mode to meet a significant demand for refrigeration of the air supplied to the cabin.

[0128] The same applies to the second all-electric variant in the configuration of the first arrangement according to [Fig.1 1], the cabin air conditioning unit 30 adopts the operating mode illustrated in a second arrangement similar to [Fig.7].

[0129] This "full cold" operating mode is suitable for both the first fuel cell variant and the second all-electric battery variant.

[0130] The air heater 24 is then not unused (as is the case in the state of the art, because it is totally bypassed by the air passing through the air conditioning unit of the passenger compartment 30) but on the contrary is usefully devoted to the dissipation of excess thermal power of electrical origin generated by the vehicle going downhill.

[0131] Thus, a passenger compartment air conditioning unit 30 according to the present invention, while ensuring the required refrigeration of the passenger compartment, simultaneously supplies the air heater 24 with an airflow from outside 3030 or recirculated from the passenger compartment 3010, this airflow then being, downstream of the air heater 24, rejected outside the passenger compartment air conditioning unit 30 and the passenger compartment, into the environment under the body or under the hood by a second duct 315, without degrading the acoustic, olfactory and thermal comfort then provided in the passenger compartment.

[0132] A passenger compartment air conditioning unit 30 thus provides additional power dissipation (without the need for an additional heat exchanger) made available by the airflow passing through the air heater. Conversely, in the same operating conditions, a passenger compartment HVAC unit according to the prior art does not exploit these additional heat exchange and power dissipation potentials since the air heater is completely bypassed by the air passing through the passenger compartment HVAC unit, which is entirely dedicated to passenger compartment cooling.

[0133] [Fig.7] illustrates the third particularly advantageous arrangement of the first The fuel cell variant, and the second similar arrangement of the second all-electric variant, in each case according to the configuration then assumed by the passenger compartment air conditioning unit 30 according to the invention in this "full cooling" operating mode, in the event of a high demand for cooling the air supplied to the passenger compartment and with, at the same time, a significant need for dissipation of excess power. The cooling is then active and the recirculation flap 301 directs the air to the evaporator 304 entirely from the passenger compartment recirculated air intake 3010. This position of the recirculation flap 301 connects the air intake of the additional duct 312 bypassing the evaporator 304 with the outside air intake 3030 downstream of the filter 303. This position of the recirculation flap 301 initiates the circulation through the passenger compartment air conditioning unit 30 of two separate air streams, which do not mix.

[0134] If, according to another non-preferred architecture, the air intake of the additional duct 312 bypassing the evaporator 304 is disposed downstream of the recirculation flap 301, through an additional flap disposed between the recirculation flap 301 and the conventional blower 302 and then open, then the additional duct 312 bypassing the evaporator 304 and the duct 3040 conveying air to the evaporator 304 are both supplied, via the same upstream duct downstream of the recirculation flap 301, by recirculated air from the passenger compartment 3010.Thus, according to this architecture, the additional duct 312 bypassing the evaporator 304 (for dissipating excess power) and the duct 3040 conveying air to the evaporator 304 (for passenger compartment cooling) are in competition, requiring a corresponding increase in the rotation speeds of the conventional blower 302 and the additional blower 313 (with the effect, in particular, of increasing the noise of air intake by both blowers 302 and 313) in order to at least maintain the flow of refrigerated air through the passenger compartment: it is therefore a non-preferred architecture.

[0135] In this "full cold" operating mode, in the event of a significant demand for cooling of the air supplied to the passenger compartment and with at the same time a significant need for power dissipation, the conventional blower 302 and additional blower 313 are activated and a flap 314 ensuring the outlet of the additional bypass duct 312 of the evaporator 304 into the mixing chamber 3070 of the passenger compartment air conditioning unit 30 upstream of the air heater 24, is opened. The flap 306, which conventionally ensures the bypass of the air heater 24 by the air from the evaporator 304, then occupies a position such that all the airflow from the evaporator 304 bypasses the air heater 24 and that the airflow from the additional bypass duct 312 of the evaporator 304 passes entirely through the air heater 24. The flap 316 releases the fluidic connection of air downstream of the air heater 24 to a second duct 315 opening under the hood or preferably under the body.Thus, the airflow heated by passing through the heater 24 is discharged outside the passenger compartment air conditioning unit 30 and the passenger compartment, into the environment under the hood or under the body, without being mixed, downstream of the heater 24, with the airflow that has simultaneously passed through the evaporator 304 to be cooled before being introduced into the passenger compartment via the "head" ducts 311 and / or "foot" ducts 310 and / or "demist / defrost" ducts 309, depending on the position of the associated air distribution flaps. This configuration of the passenger compartment air conditioning unit 30 in "full cooling" mode, particularly due to the position of the recirculation flap 301, creates two separate, independent air circuits through the passenger compartment air conditioning unit 30, which do not mix.

[0136] [Fig-8] illustrates the configuration of a fourth arrangement of the first variant with fuel cell or a third arrangement of the second all-electric variant, which allows for increased thermal power dissipation through the air heater 24 by means of its passage through colder cooling air, taken downstream of the evaporator 304, and which allows for an increase in the load applied to the air conditioning compressor with an iso-moderate need for passenger compartment refrigeration.

[0137] In this configuration, the passenger compartment air conditioning unit 30, while providing the required passenger compartment cooling, simultaneously supplies the heater 24 with a flow of cold air drawn downstream of the evaporator 304. This airflow is also discharged, downstream of the heater 24, into the environment under the body or under the hood, via the second duct 315. Cooling is then active, and the recirculation flap 301 directs the air to the evaporator 304 entirely from the passenger compartment recirculated air intake 3010. This position of the recirculation flap 301 connects the air intake of the additional duct 312 bypassing the evaporator with the outside air intake 3030 downstream of the filter 303.The conventional blower 302 and additional blower 313 are activated and the flap 314 ensuring the outlet of the additional duct 312 bypassing the evaporator 304 into the mixing chamber 3070 of the passenger compartment air conditioning unit 30 upstream of the air heater 24, is open. The flap 306, which conventionally ensures the bypass of the air heater 24 by the air from the evaporator 304, then occupies a position such that the flow of fresh air from the evaporator 304 is distributed between a first part opening into the passenger compartment via the ducts 311 "head" and / or 310 "feet" and / or 309 "demist / defrost" according to the position taken by the associated air distribution flaps, and a second part opening into the mixing chamber 3070 upstream of the air heater 24, mixing with the air flow from the additional duct 312 bypassing the evaporator 304, the air flow from this mixture then passing entirely through the air heater 24.

[0138] Alternatively, the additional blower 313 is inactive, and the flap 314 ensuring the outlet of the additional bypass duct of the evaporator into the mixing chamber 3070 of the passenger compartment air conditioning unit 30 upstream of the heater 24 is closed, so that the second part of the fresh air flow from the evaporator 304 passes through the heater 24 without being mixed with the air from the additional duct 312.

[0139] Downstream of the heater 24, the associated flap 316 releases the air fluid connection to the second duct 315, which opens under the hood or preferably under the body. Thus, the airflow heated by passing through the heater 24 is discharged outside the passenger compartment air conditioning unit 30 and the passenger compartment, into the environment under the hood or under the body, without being mixed in any way, downstream of the air heater 24, with the airflow having in parallel passed through the evaporator 304 to be cooled before its introduction into the passenger compartment via the ducts 311 "head" and / or 310 "feet" and / or 309 "demist / defrost" depending on the position taken by the associated air distribution flaps.

[0140] This configuration taken by the passenger compartment air conditioning unit 30 in the "full cold" operating mode, in particular by the position taken by the recirculation flap 301, creates through the passenger compartment air conditioning unit 30 two separate air circuits which do not mix.

[0141] As an alternative to the configuration illustrated in [Fig.8], taken by the passenger compartment air conditioning unit 30 in the "full cold" operating mode, for a significant demand for refrigeration of the air supplied to the passenger compartment and with at the same time a significant need for power dissipation, the air passing through the evaporator 304 is drawn from outside 3030 through the filter 303.

[0142] As an alternative to the previous configurations, illustrated in [Fig.7] and [Fig.8], taken by the cabin air conditioning unit 30, for a significant demand for refrigeration of the air supplied to the cabin and with at the same time a significant need for power dissipation, the air passing through the evaporator 304 is drawn from outside 3030 through the filter 303.

[0143] The simultaneous implementation of the configurations illustrated in [Fig. 5] and [Fig. 7] or [Fig. 8] assists the cooling of the fuel cell 10 when it delivers high power in harsh environmental conditions. In this case, the first heater 25 of the passenger compartment heating circuit 110 is inactive and the second valve 18 is open. Thus, the hot fuel cell coolant from the stack of cells 19 flows in parallel through the high-temperature radiator 12, through which it dissipates its heat to the outside air (first fan motor unit 13 active or not), and the air heater 24 which, thanks to the arrangement of the passenger compartment air conditioning unit 30, provides the vehicle 1000, via the high-temperature circuit 100, with an additional source of heat dissipation to the outside air, without impacting thermal comfort in the passenger compartment.

[0144] Thus, a simultaneous implementation of the configurations illustrated in [Fig.1 1], [Fig.7] and [Fig.8] in the second all-electric variant, makes it possible to assist the dissipation of excess power generated by the vehicle by dedicating the air heater 24 to it which, thanks to the arrangement taken by the air conditioning unit of the passenger compartment 30, provides the vehicle 1000, via the heating unit 110, with an additional source of thermal power dissipation to the outside air, without impacting thermal comfort in the passenger compartment.

[0145] The following provisions, adopted simultaneously with the preceding ones, increase the excess power dissipation capacity of the traction chain, by implementing for this purpose the low temperature circuits 130 and very low temperature circuits 120. Only the configurations specifically developed within the framework of the invention are explained here; the conventional configurations ensuring the thermoregulation of the electrochemical motor storage 26 and the cooling of the other components carried by these circuits are not illustrated or described since they are known from the prior art.

[0146] In the first variant relating to FCEV fuel cell electric vehicles, [Fig.9] illustrates a fifth arrangement according to a configuration adapted to vehicle operating conditions such that it is necessary to activate the excess power dissipation process, the fourth valve 38 decouples the low temperature 130 and very low temperature 120 circuits, and the thermoregulation setpoint of the electrochemical drive storage 26 is set to a temperature such that after implementation of the excess power dissipation process, the temperature of the electrochemical drive storage 26 does not exceed 50°C, given that the electrochemical drive storage 26 does not then exchange current.This configuration then activates simultaneously and deliberately inefficiently the electric heater 43 of the electrochemical drive storage unit 26 and the air conditioning compressor included in the vehicle's refrigeration circuit in order to, via the second heater 43 which heats a portion of very low temperature coolant which passes through it after the fourth pump 42 and the fourth valve 38, and via the coolant / cabin refrigerant heat exchanger 41 which cools the other portion of very low temperature coolant which passes through it after the fourth pump 42 and the fourth valve 38, supply the very low temperature coolant at the required temperature to the electrochemical drive storage unit 26 inlet in order to ensure the thermoregulation of the electrochemical drive storage unit 26 at the expected setpoint.

[0147] In the second all-electric variant, [Fig. 13] illustrates a fourth arrangement according to a configuration adapted to vehicle operating conditions such that it is necessary to activate the excess power dissipation process, the fourth valve 38 decouples the low temperature 130 and very low temperature 120 circuits, and the thermoregulation setpoint of the electrochemical motor storage 26 is set to a temperature such that after implementation of the excess power dissipation process, the temperature of the electrochemical motor storage 26 does not exceed 50°C, given that the electrochemical motor storage 26 does not then exchange current.

[0148] This configuration then activates simultaneously and in a deliberately inefficient manner the electric heater 43 of the electrochemical drive storage unit 26 and the air conditioning compressor included in the vehicle's refrigeration circuit in order to, via the second heater 43 which heats a portion of very low temperature coolant which passes through it at the end of the fourth pump 42 and the fourth valve 38, and via the cabin coolant / coolant exchanger 41 which cools the other portion of very low temperature coolant which passes through it at the end of the fourth pump 42 and the fourth valve 38, supply the very low temperature coolant at the desired temperature to the electrochemical drive storage unit 26 in order to ensure the thermoregulation of the electrochemical drive storage unit 26 at the expected setpoint.

[0149] In the first variant relating to FCEV fuel cell electric vehicles, and the fifth arrangement according to [Fig.9], the low temperature circuit adopts a configuration known from the state of the art, however with its third pump 27 activated at its maximum setpoint, not only in order to dissipate part of the excess power, but also in order to ensure the cooling, in particular of the electrical machine(s) 40 used deliberately inefficiently in order to increase their losses, of all the DC / DC converters or inverters, also used deliberately inefficiently for example by increasing their switching losses, and of the motor and inverter of the electric air compressor of the fuel cell 10, operated at its maximum permissible power.

[0150] Alternatively, the electric heater 43 of the electrochemical motility storage unit 26 and the air conditioning compressor of the refrigeration circuit are activated, as part of the thermoregulation of the electrochemical motility storage unit 26, alternately.For example, initially the electric heater 43 is active and the air conditioning compressor is inactive (for the thermoregulation of the electrochemical drive storage unit 26, but it may also be inactive for the thermal environment in the passenger compartment) so that the temperature of the electrochemical drive storage unit 26 reaches a temperature threshold between 45°C and 50°C, then subsequently the electric heater 43 is deactivated and the air conditioning compressor is activated, for the thermoregulation of the electrochemical drive storage unit 26, in order to lower the temperature of the electrochemical drive storage unit 26 to a temperature threshold between 25°C and 35°C, and so on as appropriate until exiting the power dissipation mode.

[0151] In this configuration of this fifth arrangement, the electric heater 43 of the electrochemical storage unit and the cabin coolant / refrigerant heat exchanger 41 or chiller are connected in parallel within the very low temperature circuit temperature 120 in order to minimize hydraulic pressure losses. In a non-preferred variant (since it does not allow the sixth arrangement presented below to be implemented), the second heater 43 and the chiller, i.e. the coolant / cabin refrigerant exchanger 41, can be connected in series without changing the scope of the invention.

[0152] In the second all-electric variant, and the fourth arrangement according to [Fig. 13], the low-temperature circuit adopts a similar configuration.

[0153] In the first variant relating to FCEV fuel cell electric vehicles, [Fig. 10] illustrates a sixth arrangement according to a configuration which is a variant of that of [Fig.9].In vehicle operating conditions where it is necessary to activate the excess power dissipation process, it may be relevant, while the electrochemical drive storage unit 26 is not exchanging current, to force its cooling via the coolant / cabin refrigerant exchanger 41 or chiller to a sufficiently low temperature (for example in a range of 10°C to 25°C) in order to consume, via the activation of the air conditioning compressor of the vehicle's refrigeration circuit, excess electrical power and thus, by the thermal mass (product of the mass and the thermal capacity of the electrochemical drive storage unit 26), delay a future need for thermoregulation of the electrochemical drive storage unit 26.

[0154] At the same time, the electric heater 43 of the electrochemical motility storage unit 26 is disconnected by the fourth valve 38 from the very low temperature circuit 120, connected to the low temperature circuit 130 and activated in order to also deliberately consume excess electrical power inefficiently.This second heater 43 is then connected by the fourth valve 38 to the low temperature circuit 130 in parallel with the other components present on this low temperature circuit 130, so that the thermal power released by the heater 43 is directly dissipated to the ambient air via the low temperature radiator 28 and the second motor-fan group 29, which is preferentially active (in compromise between its electrical power consumption and its acoustic and vibration emissions), so that it too consumes excess power, without the heat thus dissipated in the low temperature coolant hindering the cooling of these other components present on the low temperature circuit 130.

[0155] These provisions of the first variant relating to FCEV fuel cell electric vehicles, in the sixth provision according to [Fig. 10], are applicable to the second all-electric variant according to a fifth provision illustrated in [Fig.14], which is a variant of its fourth provision according to [Fig.13].

[0156] The method according to the invention ensures a function of comfort and customer satisfaction. Naturally, the conventional braking system must remain designed to ensure critical safety.

[0157] The thermal management system 500 is advantageously grafted onto the hardware base of any current vehicle thermal management system, uses information from the same sensors (coolant temperature, coolant temperature, oil temperature), and the same actuators, and includes means for controlling pumps, single or multi-way circulation valves, motor-fan units, circulation flaps in the passenger compartment air conditioning circuit, and for switching on or off the various usable heat sinks.

[0158] The processes, methods, or algorithms referred to herein may be provided or implemented by a processing device, controller, calculator, or computer, which may include any existing or dedicated programmable electronic control unit. Similarly, the processes, methods, or algorithms may be stored as data and instructions executable by a controller, calculator, or computer in many forms, including, but not limited to, information stored permanently on non-writable storage media, such as ROM devices, and information stored in parallel on writable storage media such as floppy disks, magnetic tapes, CDs, DVDs, RAM devices, and other magnetic and optical media. The processes, methods, or algorithms may also be implemented in a software executable object.Furthermore, processes, methods, or algorithms can be incorporated in whole or in part using appropriate hardware components, such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), state machines, controllers, or other hardware components or peripherals, or a combination of hardware, software, and firmware components.

[0159] The invention is not limited to the embodiments, means, and configurations described above. The invention also extends to all equivalent means, configurations, and embodiments, as well as to any technically feasible combination of these means, configurations, and embodiments. The embodiments and examples described above offer particular advantages and are not limiting to the implementation of the invention.

[0160] In the variant where the motor vehicle 1000 is a fuel cell electric vehicle (FCEV), the minimum electrical power generated by the fuel cell can be dissipated as thermal power released outside the vehicle if no electrical consumer is then able to The vehicle has an additional, continuously available source of power dissipation, for example, to dissipate the minimum electrical power generated by a fuel cell. This power can then be dissipated as heat released outside the vehicle if no electrical consumer is available to absorb it, thus reducing fuel cell start / stop cycles and increasing its lifespan. The fuel cell stack is protected from any disruption to its thermal regulation. The fuel cell, and in particular its cell stack, advantageously benefits from a second cooling source. The implemented process reduces or eliminates the need for severe operation of the fuel cell's electric air compressor, thereby increasing its lifespan.The fuel cell, and in particular its stack of cells, has a second source of cooling (the air heater via the cabin air conditioning unit outside) adding relatively few components to the known state-of-the-art system.

[0161] Implementing the invention requires few special components; choosing an air conditioning unit according to FR3070315 B1 is advantageous for all vehicle powertrain variants. The fluid loop architectures illustrated in the figures allow for the explicit and inefficient dissipation of electrical power.

[0162] In particular for the first fuel cell variant a separate fluidic loop 110 includes the first heater 25 and the air heater 24 with the liquid / liquid exchanger 17 with the high temperature cooling circuit 100.

[0163] Or, for the first fuel cell variant and the second all-electric variant, the arrangement of the heater 43 located between the low temperature cooling circuits 130 and very low temperature 120 allows the thermal power generated within the heater 43 (by the excess electrical power) to be dissipated either through the low temperature radiator 28 (in parallel with the other components of the loop, so as not to impact them), or in the very low temperature cooling circuit 120 (simultaneous or alternative activation with the liquid / refrigerant exchanger 41: heating and cooling at the same time or alternately, storing heat and / or cold in the electrochemical storage unit 26 thanks to its large thermal mass).

[0164] Hence the implementation of additional valves and conduits. Any safety risk of overheating, degradation, ignition, boiling of the vehicle's friction braking system, and of accident, is eliminated, and the vehicle thus has an increased potential for long distances or downhill driving time.

[0165] The process described herein ensures a function of comfort and customer satisfaction, but not the critical safety function, for which the conventional braking system must be designed.

[0166] In the prior art, electric and / or fuel cell vehicles conventionally have an electrical braking resistor. This is a dedicated component, added to the conventional nomenclature of the vehicle (its composition), dissipating excess electrical power as heat. The advantage is that, being dedicated, it is sized accordingly and available at all times to perform its function. Its disadvantages are its cost and its integration into the vehicle (geometric layout, high-voltage electrical network of the vehicle).

[0167] The invention does not require dedicated equipment, and is committed to managing power by making the best use of the existing equipment, constituting the various heat sinks described above, by deliberately making them operate inefficiently, in order to avoid any additional equipment costs, and to control the potential impacts of these more or less abnormal operating modes on their durability.

[0168] The electric heater located on the vehicle's passenger compartment heating circuit is not used in the prior art because existing systems do not always have a source for dissipating the generated thermal power, which is provided by the air conditioning unit implemented by the invention.

[0169] The air conditioning compressor explicitly operates beyond the just necessary requirement, to consume some excess power (generate more cold than expected), which is compensated for by heating this air (or the coolant or refrigerant fluid) which is too cold to return to the expected setpoint value (again consuming excess power).

[0170] In the prior art and by definition, the electric heater of the HVB electrochemical energy storage unit is never positioned within the same low-temperature fluid loop as components other than the battery, and is never directly connected to the inlet of the low-temperature radiator. Indeed, by activating this heater, the heat generated by the invention through the heater is dissipated directly via the radiator to the outside air without any further processing.

[0171] In summary, the invention goes against the normal concepts of use of the various components of the traction chain, cooling circuits, and air conditioning, and uses for a common purpose of dissipation of excess power what would be a set of energy malfunctions outside the particular context of the invention.

[0172] In particular, and without limitation, the fan motor units and / or pumps are activated when not necessary, or at setpoints higher than those required. Or, an electrical machine, its inverter, and other current converters are deliberately operated inefficiently (for example, by increasing their operating frequency). Or, a component is heated and cooled simultaneously and deliberately inefficiently to a given temperature, a temperature that could have been met much more efficiently with less energy consumption.

[0173] The invention also focuses on reducing the number of components.

[0174] In particular, the present description mentions a single air heater. This does not exclude the possibility of a plurality of air heaters, which is necessary for vehicles such as buses or for passenger transport which may have several, these air heaters being able to be arranged in series or preferably in parallel with each other.

[0175] On the other hand, there is no air heater within the low and very low temperature cooling circuits, because the temperature of the coolant and the thermal power that can be dissipated in the passenger compartment (through the air heater) are then insufficient to meet the need on their own.

[0176] For the first fuel cell variant, as a non-preferred alternative, the air heater and the heater are arranged within the fuel cell cooling circuit, in place of the liquid / liquid exchanger, with or without the dedicated pump.

[0177] For the second all-electric variant, as a non-preferred alternative, the circuit of [Fig. 11] can be replaced by a single heater of the type directly heating the air entering the passenger compartment.

[0178] In summary, the proposed process makes it possible to use additional non-specific sources of power dissipation in order to dissipate the excess power of the vehicle on a slope, in the form of heat, in particular diffused towards the external environment, providing a significant margin with regard to the safety risks of overheating, degradation, ignition, boiling of the conventional friction braking system of the vehicle, and to the risks of accident, and ensuring the user a potential for long distances or downhill driving time without risk.

[0179] The vehicle thus has an additional source of power dissipation, available continuously, for example, in the first fuel cell variant, to dissipate the minimum electrical power generated by a fuel cell. This power can then be dissipated as thermal power released outside the vehicle, if no electrical consumer is then able to absorb it.

[0180] The vehicle downhill speed control thus proposed reduces the total cost of ownership for the user (reliability / durability of the friction braking system increased by reducing its use downhill).

[0181] The invention allows for immediate vehicle responsiveness in the event of a need to dissipate power; its response time is very short, the control actions of the pumps, valves, flaps and heat sinks are immediate, which makes it possible to dissipate excess power for a short period, of a few seconds or minutes, in a particular phase of vehicle evolution.

Claims

1.

2. Demands Energy regulation method during the long descent phase of a hybrid or electric motor vehicle (1000) comprising at least one energy source from a fuel cell (10) or an electrochemical energy storage unit (26), a thermal management system (500) of the powertrain associated with this at least one energy source, at least one heat transfer fluid loop (110, 120, 130), and at least one passenger compartment air conditioning unit (30) comprising a plurality of air circulation flaps, and a passenger compartment heating circuit (110), said vehicle (1000) comprising at least one low-temperature cooling circuit (130) of at least one electric powertrain (40) powered by an electrochemical energy storage unit (26), and a very low-temperature thermoregulation circuit (120) of said electrochemical energy storage unit (26),characterized in that said passenger compartment air conditioning unit (30) is arranged to allow the separation of two independent airflows, one for air conditioning the passenger compartment of said vehicle and the other for heat exchange with the external environment of said vehicle (1000), and in that said thermal management system (500) of said vehicle (1000) is arranged to, when said vehicle (1000) is in a long descent phase, control the dissipation of excess energy produced by said vehicle (1000) and / or said at least one energy source in at least one heat sink which is an element of said very low temperature cooling circuit (120) or which is an element of said low temperature circuit (130), by coupling at least one heat transfer fluid loop (110, 120, 130) of said vehicle (1000) with said passenger compartment air conditioning unit (30),and by coupling the heat sink, which is an element of said very low temperature cooling circuit (120), to said low temperature circuit (130), in an additional operating mode to increase the electrical power dissipated by the thermal systems comprising said vehicle (1000) and to increase the cooling potential of said at least one energy source. The method according to claim 1, characterized in that said thermal management system (500) of said vehicle (1000) is arranged so that, when said vehicle (1000) is in a long descent phase,

3.

4.

5. control the dissipation of excess energy produced by said vehicle (1000) and / or said at least one energy source in at least one heat sink which is an element of said at least one heat transfer fluid loop (110, 120, 130), using said at least one heat sink differently from its nominal use, and using said low temperature cooling circuit (130) to reject excess thermal energy out of the vehicle as required for passenger comfort. Method according to claim 2 characterized in that said air circulation flaps of said at least one cabin air conditioning unit (30) are oriented to expel excess thermal energy from the vehicle as required for cabin comfort.A method according to claim 2 or 3 characterized in that said vehicle is equipped with a high-temperature cooling circuit (100) for cooling said at least one energy source, and in that said thermal management system (500) of said vehicle (1000) is arranged to, when said vehicle (1000) is in a long descent phase, control the dissipation of excess energy produced by said vehicle (1000) and / or said at least one energy source in at least one heat sink constituted by an element of said high-temperature cooling circuit (100) and / or said low-temperature cooling circuit (130), using said at least one heat sink differently from its nominal use, and orienting said air circulation flaps of said at least one cabin air conditioning unit (30) to expel excess thermal energy from the vehicle as required for cabin comfort. The method according to claim 4 is characterized in that said thermal management system (500) is arranged to control the dissipation of excess energy produced by said vehicle (1000) and / or said at least one energy source in at least one heat sink constituted by an element of said high-temperature cooling circuit (100), by controlling at least one first circulation pump (11) comprising said high-temperature cooling circuit (100) or a second circulation pump (23) comprising said passenger compartment heating circuit (110) to manage the flow through a heater (24) comprising said passenger compartment air conditioning unit (30), by controlling a first valve

6.

7. (15) and a second valve (18) comprising said high-temperature cooling circuit (100), by controlling a first electric heater (25) comprising said heating circuit (110) of the vehicle's passenger compartment, by controlling a first motor-fan group (13) comprising said high-temperature cooling circuit (100) associated with a first radiator (12). A method according to any one of claims 1 to 5, characterized in that said thermal management system (500) is arranged to control the dissipation of excess energy produced by said vehicle (1000) and / or said at least one energy source in at least one heat sink constituted by an element of said low-temperature cooling circuit (130), by controlling a third circulation pump (27) and a fourth circulation pump (42) and a third valve (32) and / or a fourth valve (38) comprising said low-temperature cooling circuit (130), by controlling a second electric heater (43) of said electrochemical energy storage unit (26) comprising said low-temperature cooling circuit (130), by controlling a second motor-fan assembly (29) comprising said low-temperature cooling circuit (130) associated with a second radiator (28), by controlling said at least one electric powertrain assembly (40),a DC / DC converter (36, 37) comprising said low-temperature cooling circuit (130), and a coolant / cabin coolant heat exchanger (41) comprising said very low-temperature cooling circuit (120). A method according to claims 5 and 6, characterized in that said thermal management system is arranged to control the dissipation of excess energy produced by said vehicle (1000) and / or said at least one energy source in at least one heat sink constituted by an element of said high-temperature cooling circuit (100), by controlling at least said first circulation pump (11) comprising said high-temperature cooling circuit (100) or said second circulation pump (23) comprising said vehicle passenger compartment heating circuit, to manage the flow through a heater (24) comprising said passenger compartment air conditioning unit (30), by controlling said first valve (15) and said second valve (18) that includes said high-temperature cooling circuit (100), by controlling said third circulation pump (27) and said fourth circulation pump (42) and said third valve (32) and / or said fourth valve (38) which includes said low-temperature cooling circuit (130), an optional electric air conditioning compressor, an optional electric supercharging compressor from at least one said energy source, said first electric heater (25) which includes the vehicle passenger compartment heating circuit, said second electric heater (43) of said electrochemical drive storage unit (26), said first cooling fan assembly (13) which includes said high-temperature cooling circuit (100) associated with a first radiator (12), said second cooling fan assembly (29) which includes said low-temperature cooling circuit (130) associated with said second radiator (28),said at least one electric powertrain (40), said DC / DC converter (36, 37), said coolant / cabin refrigerant heat exchanger (41).

8. Method according to claim 6 or 7 characterized in that said vehicle passenger compartment heating circuit (110) is replaced or supplemented by a very low temperature thermoregulation circuit (120) of said electrochemical drive storage unit (26), under the action of said passenger compartment coolant / coolant exchanger (41).

9. A method according to any one of claims 6 to 8 characterized in that said second electric heater (43) of said electrochemical motor storage unit (26), or of said low temperature cooling circuit (130), or of said very low temperature thermoregulation circuit (120), is connected to provide said vehicle (1000) and / or said at least one energy source with an additional source of power dissipation without impacting the other components.

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