WO2023281196A1

WO2023281196A1 - Method for managing the operation of a fuel cell generator

Info

Publication number: WO2023281196A1
Application number: PCT/FR2022/051327
Authority: WO
Inventors: Rémi SUCCOJA; Ramzi Sellaouti
Original assignee: Pragma Industries
Priority date: 2021-07-08
Filing date: 2022-07-04
Publication date: 2023-01-12
Also published as: FR3125177B1; FR3125177A1

Abstract

Method for managing the operation of an electrical fuel cell generator comprising, when hydrogen starts being supplied to the fuel cell with a gradual rise in the voltage of said cell, a start mode (720) comprising supplying the central unit with a limited first output voltage from the cell sufficient to charge the first supercapacitor stage of the first circuit, disconnecting the second circuit by way of the central unit, a mode of preheating the cell (730) in which the central unit authorizes charging of the second supercapacitor stage (42) of the second circuit and keeps the circuit of said at least one power output (52a,..., 52n) open until the cell reaches a nominal operating voltage (760), and an operating mode in which the central unit authorizes the supply of said at least one SHP power output, the method furthermore comprising a stop sequence (860, 870, 880) initiated by the central unit upon detection of an output power or voltage drop of the cell for a given time.

Description

METHOD FOR MANAGING THE OPERATION OF A BATTERY GENERATOR

FUEL

Technical area

This disclosure falls within the field of fuel cell power supply devices and in particular power supply devices for equipment such as portable personal computers (laptop PCs), portable telephones, lighting or other devices, or vehicles of the electric bicycle type using a fuel cell associated with an unregulated hydrogen production source, and without a battery. Prior technique

[0002] It is known to produce power supply devices using fuel cells, or hydrogen cells, as the primary source of energy. [0003] The document US2020/0044299 A1 relates to a fuel cell power supply device whose regulation implements a battery, a hydrogen cell and a supercapacitor for which the management of the fuel cell depends on the state of battery charge. Such a device, which uses three energy sources, is complex to manage and its proper functioning depends on the proper functioning of the battery, which is a heavy object and whose life is limited. The document CN 105299495 A provides a fuel cell power supply device whose hydrogen is produced from methanol and provides for regulating the production of hydrogen and a stack of fuel cell sub-cells comprising a supercapacity. In this document, a regulation of the production of hydrogen is provided for.

[0005] These documents are difficult to apply to a device that does not include a battery and whose hydrogen production source cannot be regulated, as in the case of a reactive material in powder form producing hydrogen when it is brought into contact with water, the reaction of which cannot be regulated, or in the case of a pressurized hydrogen bottle if you do not wish to manage the arrival of hydrogen. Furthermore, it is desirable to eliminate the buffer battery of prior devices in order to limit the weight of portable devices and their storage life in particular. Summary

[0006] With respect to the prior art, the present disclosure thus aims to improve the management of the operation of a fuel cell electric generator without a buffer battery and without regulation of its hydrogen supply source. to make its start-up, operation and shutdown independent of the hydrogen flow in the fuel cell.

To do this, the present disclosure provides a method for managing the operation of a fuel cell electric generator comprising:

- a first circuit for supplying energy to a low-consumption central unit for controlling said generator, said first circuit, connected to the fuel cell, being provided with a first stage of LPSC supercapacitors, supplying said central unit,

- at least one second circuit, called power circuit, for supplying energy to at least one supply power output of equipment connected to said generator, separate from the first circuit, said second circuit, connected to the fuel cell , being provided with a second stage of supercapacitors HPSC (also called HP SCAP), the first circuit being configured so that the first stage of hybridization with supercapacitors provides a reserve of energy adapted to allow the power supply of the unit power plant to be independent of the operation of the second circuit, the method comprising, when the hydrogen supply of the fuel cell begins with a gradual increase in voltage of said cell, a start-up mode comprising a supply of the unit central unit by a first limited battery output voltage sufficient to charge the first stage of supercapacitors of the first circuit, a cut-off of the second circuit by the central unit, a prec heating of the battery for which the central unit authorizes the charging of the second stage of supercapacitors of the second circuit and keeps the circuit of said at least one power output open until the battery reaches a nominal operating voltage and a mode operation for which the central unit authorizes the supply of said at least one power output SHP, the method further comprising a shutdown sequence initiated by the central unit upon detection of a drop in the output voltage of the battery for a given time. [0008] The start-up sequence may include a battery output voltage test and for which, in the event that the battery output voltage does not reach a minimum value Vo after a given number of trials in the sequence starting, the generator said stop sequence. [0009] The preheating sequence may comprise a test sequence of output voltage of the first stage of supercapacitors VLPSC and output voltage of the second stage of supercapacitors VHPSC repeated as long as the output voltage of the first stage and the output voltage of the second stage have not reached given nominal values and ending either by passing to said on stage if said output voltages have reached said nominal values, or by triggering said stop sequence if the temperature Q of the battery exceeds a maximum temperature of 0 _ma x.

[0010] This preheating sequence allows the supercapacitors of the second circuit to be charged while checking that the temperature of the battery remains within acceptable limits.

The running sequence may comprise a first loop comprising a first comparison between the battery output voltage V _P ii _e and a threshold voltage Vmin, said loop triggering a regeneration loop comprising at least one calibrated purge of the battery when the battery voltage is lower than said threshold voltage.

[0012] It should be noted that the threshold voltage V _m in is lower than the no-load voltage of the cell Vo according to the traditional current/voltage curve of a fuel cell.

[0013] The regeneration loop may comprise a second loop provided with a second comparison between the battery output voltage and said threshold voltage and for which said shutdown sequence is triggered if the battery output voltage remains below said threshold voltage for a duration U _max and for which the generator returns to the running sequence if the battery output voltage has again become greater than or equal to said threshold voltage after a said calibrated purge for a duration less than T 1 _day x.

[0014] Said stop sequence may comprise the cut-off of the power output or outputs, the cut-off of a supply converter of the second stage of HPSC supercapacitors. [0015] The shutdown sequence may include an opening of the purge solenoid valve which will empty the hydrogen circuit of the cell.

[0016] The shutdown sequence may also comprise the shutdown of the cell, the discharge of the first stage of supercapacitors and a shutdown of the central unit.

[0017] The battery comprising a temperature sensor and a fan connected to the central unit, the method may comprise stopping said fan during the start-up sequence and during the stop sequence, starting at low speed said fan during the preheating sequence and operation of the fan at a speed controlled by the central unit as a function of the temperature of the stack in the running and regeneration sequences.

Brief description of the drawings

[0018] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the appended drawings, in which: [0019] [Fig. 1] shows a block diagram of an electric generator;

[0020] [Fig. 2] shows a detail diagram of an example of a CPU power supply circuit;

[0021] [Fig. 3] shows a detailed diagram of a first embodiment of a supercapacitor hybridization stage;

[0022] [Fig. 4] shows a detailed diagram of a second embodiment of a supercapacitor hybridization stage;

[0023] [Fig. 5] shows a purge solenoid valve management flowchart;

[0024] [Fig. 6] shows an example of a flowchart and operating states of a generator that can be produced according to the present disclosure.

Description of embodiments

According to Figure 1, the architecture proposed for the fuel cell electric generator of the present disclosure is based on the production of a first circuit, LP circuit, for supplying energy to a device for managing the operation of the generator, the first circuit being provided with a first supercapacitor hybridization stage 43, and with at least one second circuit, HP circuit, for supplying energy to at least one power output 52a for supplying equipment connected to the electricity generating device, the second circuit being provided with a second supercapacitor hybridization stage 42 distinct from said first stage. Thus the present disclosure relates to a fuel cell electrical generator comprising a separation of the generation of electricity intended to produce current to supply one or more external devices and the generation of electricity of the operating management circuit of the generator. To give an example, the present disclosure is addressed in particular to a generator comprising a battery sized to deliver 8.6A at 0.63V/cell for 8 cells.

The invention is however not limited to these values and the battery may in particular comprise more or fewer cells and deliver more or less current depending on its configuration.

The generator operation management device ensuring the management of the electric generator comprises a central unit 60, microprocessor or microcontroller which constitutes a control/command or piloting device for the generator receiving voltage/current information from various stages of the electric generator and which controls circuit control means as will be seen later.

The generator operating management device is powered from the fuel cell 10 by the first circuit which comprises a power supply buffer regulated by a first stage of independent supercapacitors 43 provided with a first charging circuit 31 a balancing circuit 41 and which is followed by a DC/DC converter (hereafter DC/DC converter) 53 to supply the central unit 60. The central unit comprises a microprocessor or a microcontroller associated with a memory 61 which comprises a part of non-volatile memory in which is located the generator management program and a part of working random access memory.

This first low-power circuit called the LP circuit can be sized so as to provide a long-term energy reserve for supplying the central unit. The charging circuit 31 then comprises a DC/DC step-up converter 31a represented in FIG. 2, the output of which is connected to an SBC device 41 for controlling and balancing the cells to which the supercapacitors 431, 432, 433 are connected, the converter 31a and the control and balancing device 41 respectively comprising modules 23, 24 for monitoring and transmitting voltage and current data on a bus, for example a l ² C or SMBUS bus connected to the central unit 60 The circuit provides power to the unit power station through a second step-down DC/DC voltage converter 53a provided with an SLP output compatible with the operating voltage of the low-power microprocessor or microcontroller-type CPU. [0032] The central unit will manage the auxiliaries of a battery balancing unit (BOP for Balance of Plant in English) i.e. the purge solenoid valve 71, a cooling fan 73 of the battery and receive information temperature of the battery by means of a temperature sensor 72 as represented in FIG. 4. The control command device also manages the starting and stopping of the DC/DC converters of the load circuits and the safety switches of the power outputs. It will control the output voltage of the battery, in particular during the transitional phases of start-up, purge and shutdown of the battery to check that the battery provides sufficient output voltage.

[0033] In particular, the central unit will manage the operating parameters of the fuel cell 10 such as in particular the management of the purge solenoid valve 71 of the cell during the transitional phase of start-up of the cell, of the transitional phase stoppage of the cell and the phases of purging the cell during its operation, that is to say the phases of opening of the purge solenoid valve to evacuate the water generated by the operation of the cell. The central unit will also manage the temperature of the battery by means of the temperature measurement of the battery by the sensor 72 and the starting, the stopping and the speed of the fan 73 for cooling the battery which will be slaved to the battery temperature. This speed is controlled by a PWM circuit according to a control law dependent on the current generated by the battery.

As regards the power outputs, the second circuit, a simplified diagram of which is given in FIG. 4, comprises, as said above, a hybridization stage 40, 42 with supercapacitors which is intended to supply the necessary power at the output of generator during transient phases of limited duration where the fuel cell output power is lower than the system output demand.

This second circuit, called power circuit, distinct from the first circuit, comprises a charging circuit provided with a third DC/DC converter 30a followed by a stage of supercapacitors 42 comprising several supercapacitors 420, 421, 422, 423 the load of which is balanced by a circuit 40 for balancing and protection. The starting and stopping of the third converter are controlled by the central unit through a command 301. At the output of the stage of supercapacitors, the second circuit comprises one or more fourth DC/DC converters 50a, 50b, ..., 50n depending on the voltages to be supplied on power paths S1, S2, ... which will supply devices connected to the generator. These channels are for example a 12V power channel, a 5V channel or other. [0036] Due to the fact that the supply of the central unit and of the balancing unit of the stack is based on an energy buffer independent of the supply circuit of the power outputs and comprising an energy reserve not impacted by the power consumed by these outputs, the management of the generator is possible even when the power supplied by the battery decreases and becomes insufficient to supply said outputs. When the central unit detects a drop in the output voltage of the battery such that the supply of the power output(s) is no longer possible, it orders the stopping of the DC/DC converters supplying said outputs before starting a system shutdown procedure and its own standby. [0037] Furthermore, by measuring the voltages and currents 21, 22 on the output channel(s) 50a, 50b, etc. of the power circuit and the switch means 301, 51 at the level of the power circuit and of the DC/DC power supply converters for the outputs shown in FIG. 4 detailing the second circuit, the central unit is able to cut off the power supply to said outputs in the event of excessive consumption or a short-circuit on one or the other of these outputs. Either we detect an overconsumption of current on one of the outputs and we cut this output then we temporarily reactivate it cyclically to check if the fault has disappeared to resupply it, or we detect that the sum of the output powers is greater to the theoretical power of the battery for a duration greater than a given duration and all the outputs are cut off until the power requested at the output is reduced.

Furthermore, the central unit will manage the activation of the third converter 30a of the second circuit when the battery has reached sufficient power after its start-up and will manage the deactivation of this third converter and/or the deactivation of the fourth converters 50a, 50b ... of said power output(s) when the output voltage of the battery is no longer sufficient to supply the power supply to said outputs.

[0040] As shown in Figure 1, the device may comprise at the level of the first circuit a bypass downstream of the supercapacitor stage with a fifth DC/DC converter to power battery accessories such as the cooling fan for example.

[0041] An important role of the first circuit is to supply energy to the central unit of the fuel cell as well as the balancing unit independently of the hydrogen flow rate, unknown and variable, and potentially multi-source, production by chemical reaction, pressurized bottle, etc., present at the entrance to the stack. Once the hydrogen source is connected to the cell, for example by opening a valve or starting the chemical reaction, the first circuit must operate as soon as a minimum voltage appears at the cell output sufficient to supply the central unit, for example with components of the traditional DC/DC converter type, a voltage greater than 2.5 V. The central unit will then control the rise in voltage of the battery, will authorize the charging of the supercapacitors of the second circuit in authorizing the charging of the supercapacitors of the second circuit through their charging circuit 30 and will only authorize the operation of the output converter(s) 50a, ..., 50n of the second circuit when the charge of the supercapacitors of this second circuit is sufficient so that these can supply the power outlets. Then the central unit: a. - monitors the voltage/current parameters of the battery to determine the need to carry out purges by opening the purge solenoid valve, checking that the opening of this solenoid valve allows a rise in the power supplied by the battery, b. - initiates any battery reconditioning phases.

[0042] The central unit will also control the controlled shutdown of the cell when the production of hydrogen is reduced to the point that the output power of the cell becomes insufficient compared to the power requested at the output of the generator during a duration greater than a first threshold or when the nominal power of the battery cannot be restored by purging.

This is achieved by stopping the production of energy in the power circuit, for example by stopping the third DC/DC converter 301 in order to conserve the residual power of the battery to supply the central unit and the auxiliary components ( BOP). The central unit will then stop the fan(s), open the purge solenoid valve and go into standby. The voltage provided by the battery will then drop completely and the first circuit will stop. Finally, in the case where the hydrogen source supplying the cell is an unregulated hydrogen source with a chemical reagent, the central unit will be connected to a temperature sensor 75 measuring the temperature of the chemical reaction and will include a control output for a fan 74 for cooling said hydrogen source so as to manage the temperature of said source as a function of the reaction temperature in order to control the chemical kinetics at the origin of the production of hydrogen .

[0045] A flow chart representing the start-up and operating phases of the cell in relation to the phases of purging the cell is represented in FIG. 5. [0046] In the case of a hydrogen supply to the cell by a device unregulated, the central unit is not powered until the cell receives hydrogen. When hydrogen begins to arrive in the cell, the voltage of the latter rises sufficiently to start the DC/DC converter of the LP charging circuit 31 and wake up the central unit in step 490. The central unit initializes, opens the purge solenoid valve VS of the hydrogen circuit of the cell and resets a purge counter CP. Once the voltage of the battery V _P ii _e is greater than a defined minimum value Vo corresponding practically to the open circuit voltage of the battery taking into account the fact that the central unit requires very little power in step 510, the device passes in a preheating mode 520, in which the battery fan operates, the charging of the supercapacitors of the second circuit is activated, comprising a time delay 530 then a closing of the purge solenoid valve VS then a test of the battery voltage at the step 550. If the battery voltage with the solenoid valve in operation, the charge of the supercapacitors of the second circuit in operation and the battery fan in operation, falls below a threshold value V _m in and therefore becomes insufficient to charge the supercapacitors of the second circuit, the purge counter CP is incremented at step 630 and, if the purge counter has not reached a limit value CPmax at test step 640, the system remains in the e preheat status. If the battery voltage remains above the predefined minimum threshold value V _m in at step 550, the system switches to a standard generator operating mode 560. Returning to test step 640, in the event that the purge counter CP has reached the limit value CPmax, a fault on the hydrogen circuit is considered at step 650, an error indicator is lit at step 652 then the system is stopped at step 654. [0047] To fix ideas, a fuel cell that can be used for the device of the invention may comprise about twenty cells each having an open circuit voltage of the order of 0.90 V to 0.95 V and which operates in current generator in its so-called ohmic range. Voltage V0 will be close to the battery's no-load voltage while voltage Vmin will be a little higher than the low voltage of the ohmic range.

When the generator is in generator operating mode 560 after the preheating phase, the HP circuit is switched on by authorizing the operation of the HP load circuit 30 and the device performs in parallel a verification of the output voltage stack at step 610 and purge sequences. The purge sequences are performed after reaching a predefined time in step 570 and include opening of the purge solenoid valve VS in step 580 for a given duration. When the fixed purge duration is reached in step 590, the purge solenoid valve is closed and the purge delay counter is reset to zero in step 600. The sequence repeats as long as the device is in its mode. operating as a generator 560. The verification of the battery output voltage V _Piie carried out in parallel at step 610 maintains the device in the operating mode as a generator as long as this voltage is greater than the threshold V _min . However, if the battery voltage drops below the threshold V _min , the device opens the purge solenoid valve VS in step 615 for a defined time delay tempo3 and, if the voltage does not recover in step 620, it is considered that the source of hydrogen is no longer capable of supplying the device, the central unit then stops the HP circuit, keeps the purge solenoid valve open and switches to stop mode at step 625. 6 represents an example of a logic diagram relating to the operating states of elements of a generator produced according to the present disclosure.

When the battery is not powered, the generator is in a stopped mode 700 for which the fan of the battery 73 is stopped, the fan of the hydrogen source 74, for example a tank in which one puts a material which releases hydrogen in the presence of water, is stopped, the purge solenoid valve 71 is in the open position in the absence of electrical power. In this mode, the LP 31 low-power load circuit, the HP high-power load circuit 30 and the output(s) 50a, 50n are inactive and the indicator lights 76, 77 are off.

[0052] When a hydrogen supply to the cell is started, the cell voltage rises and allows the start of the DC/DC converter of the LP charging circuit in step 710, the generator switches to a start mode because the cell starts powering the CPU through the low power LP load circuit. Indeed, the DC/DC converter supplying the circuit of the central unit only needs a reduced battery voltage to operate. In this step, the central unit activates an inhibition circuit 78 which keeps the high power load circuit and the power output(s) stopped. In addition, the central unit maintains the purge solenoid valve in the open position.

In step 730, a battery voltage rise test is carried out after a time delay 725 and, in the event that the battery voltage has not reached a sufficient value after 5 trials according to test 727, a procedure stop 860, 870, 880 is started.

When the battery voltage has reached a sufficient value, the generator switches to a 750 preheating mode. In this mode, the battery fan is started at low speed, for example from 10% to 20% of its rated speed depending on the type of fan used, the purge solenoid valve is put into automatic operation, i.e. it is closed but may open temporarily to purge the water from the circuit, the load circuit of the supercapacitors HPSC 42 (also called HP SCAP) is put into operation but the power outputs remain cut off. The voltage of the battery, which then operates under load, decreases with respect to Vo. When the voltage VHPSC of the supercapacitors of the HP circuit has exceeded a threshold value which corresponds to approximately 75% to 80% of their maximum load and the voltage VLPSC of the supercapacitors of the LP circuit is stabilized at a voltage sufficient for the power supply of the central unit and the battery auxiliaries in step 760 the generator switches to running mode in step 770. In the case where the voltage of the supercapacitors of the HP circuit or the voltage of the supercapacitors LPSC 43 also called LP SCAP of the LP circuit has not reached its nominal value but the temperature Q has exceeded a maximum threshold Omax 850, the generator returns to the stop sequence 860, 870, 880. In the running mode 770, the HP outputs are in operation, the correct operation indicator 76 is permanently lit and regeneration sequences 790 with purge 800 of a given duration and cut-off of the power outputs are carried out when the voltage of the battery drops below the voltage of the supercapacitors of the HP circuit in 780.

In the regeneration sequences, in the event that the battery voltage returns to normal during test 830 before the end of a time delay T1 in test 820, the generator returns to normal operating mode, on the other hand if the voltage of the battery does not return to normal at the end of the time delay T1 in test 820, the shutdown sequence is initiated.

[0058] The shutdown sequence firstly comprises cutting off the HP outputs, cutting off the charging circuit of the supercapacitors of the HP circuit, opening the purge solenoid valve in step 860, stopping the battery when the generation of hydrogen stops, which leads to the discharge of the supercapacitors of the LP circuit, the stopping of the central unit and the stopping of the ventilations in step 880.

In summary, the generator is structured around supercapacitor power converters equipped with a charging circuit, a discharging circuit and comprises a microprocessor or microcontroller calculation unit powered by a circuit independent of a circuit of power to manage the operation start-up and shutdown phases of the converter. The architecture of the generator makes it possible to overcome the state and availability of the hydrogen source for this management.

Due to its operation at low voltage relative to the HP circuit, for example a voltage of 2.5 V to 3.5 V at the battery output makes it possible to operate the converter 31a supplying the supercapacitors of the LP circuit to obtain a voltage at the output of the second converter 53a adapted to the supply of a low consumption microcontroller, the subassembly formed by the LP circuit supplies energy to the auxiliaries and the central control/command unit of the fuel cell independently of the flow rate unknown and variable hydrogen from an unregulated source present at the inlet of the stack. As a result, the central unit makes it possible to control the start-up 720, the gradual increase in power during the preheating 750, the reconditioning phases 790 and the controlled shutdown of the fuel cell 880 without power interruption for the auxiliary components 70 . The central unit manages the generator and protects the battery by monitoring its output voltage and protects the outputs and the battery against overconsumption.

This disclosure is not limited to the examples shown and in particular the generator may include operating indicators managed by the central unit to indicate the state in which it is, in particular the fact that the outputs are active or inactive. The generator device described is applicable to nomadic or emergency devices for powering devices such as emergency lighting, devices such as mobile or satellite telephone, GPS or laptop computer but is also applicable to larger power generating devices such as electric bicycles for example.

Claims

[Claim 1] A method of managing the operation of a fuel cell electric generator comprising: a. a first circuit (31, 41, 43) for supplying energy to a low-consumption central unit (60) for controlling said generator, said first circuit, connected to the fuel cell, being provided with a first stage of LPSC supercapacitors (43), supply of said central unit, b. at least one second circuit (30, 40, 42, 50a, 51, 53), said power circuit, for supplying energy to at least one power output (52a) for supplying equipment connected to said generator, separate from the first circuit, said second circuit, connected to the fuel cell, being provided with a second stage of HPSC supercapacitors (42), the first circuit being configured so that the first stage of supercapacitor hybridization provides a reserve of energy adapted to allow the power supply to the central unit to be independent of the operation of the second circuit, characterized in that it comprises, when the hydrogen supply to the fuel cell begins with a rise in voltage of said battery, a start-up mode (720) comprising a supply of the central unit by a first limited output voltage of the battery sufficient to charge the first stage of supercapacitors of the first circuit, a cut-off of the second circuit by the a central unit, a battery preheating mode (730) for which the central unit authorizes the charging of the second stage of supercapacitors (42) of the second circuit and keeps the circuit of said at least one SHP power output (52a, ..., 52n) until the battery reaches a nominal operating voltage (760) and an operating mode for which the central unit authorizes the supply of said at least one power output SHP, the method comprising furthermore a shutdown sequence (860, 870, 880) initiated by the central unit upon detection of a drop in the output voltage of the battery for a given time.

[Claim 2] Method according to claim 1, for which the starting sequence includes a battery output voltage test and for which, in the event that the battery output voltage does not reach a minimum value Vo after a given number of tries (727) in the start sequence, the generator said stop sequence (860, 870, 880).

[Claim 3] A method according to claim 1 or 2, wherein the preheating sequence comprises a test sequence (760) of first stage supercapacitor VLPSC output voltage and second stage supercapacitor VHPSC output voltage repeated as long as the output voltage of the first stage and the output voltage of the second stage have not reached given nominal values (850) and ending either by entering said on stage if said output voltages have reached said nominal values , or by triggering said shutdown sequence (860, 870, 880) if the temperature Q of the battery exceeds a maximum temperature 0 _ma x (850).

[Claim 4] Method according to claim 1, 2 or 3, for which the on sequence comprises a first loop comprising a first comparison (780) between the battery output voltage V _P ii _e and a threshold voltage V _m in, said loop triggering a regeneration loop (790) comprising at least one calibrated purge (800) of the battery when the battery voltage is below said threshold voltage.

[Claim 5] A method according to claim 4, wherein the regeneration loop comprises a second loop provided with a second comparison (830) between the battery output voltage and said threshold voltage, for which said shutdown sequence (860, 870, 880) is triggered if the output voltage of the battery remains lower than said threshold voltage for a duration U _max and for which the generator returns to the running sequence if the output voltage of the battery has again become higher or equal to said threshold voltage after said calibrated purge for a duration less than T 1 _ma x.

[Claim 6] A method as claimed in any preceding claim, wherein said shutdown sequence includes shutting down the power output(s), shutting down a power converter of the second stage HPSC supercapacitors (42) .

[Claim 7] Process according to claim 6 for which the stop sequence includes an opening of the purge solenoid valve.

[Claim 8] A method according to claim 7 wherein the shutdown sequence includes shutdown of the cell, discharge of the first stage of supercapacitors and shutdown of the CPU.

[Claim 9] Method according to any one of the preceding claims for which, the battery comprising a temperature sensor and a fan connected to the central unit, the method comprises stopping said fan during the start-up sequence, switching on running at low speed of said fan during the preheating sequence and operation of the fan at a speed controlled by the central unit as a function of the temperature of the stack in the running and regeneration sequences.