Method for monitoring discharge current peaks in a rechargeable battery of a vehicle

Abstract

The invention relates to a monitoring method for use in a vehicle comprising a rechargeable battery supplying a measurable current to a main electric circuit to which at least one electric drive machine is connected. This monitoring method comprises a step (10-30) wherein, when, in a discharge phase of the rechargeable battery, the measured current exceeds at least one threshold chosen for at least one chosen duration associated with the latter, imposing at least one reduction in the electrical power supplied by the rechargeable battery to the electric motor machine and subsequently isolating the rechargeable battery from the main electrical circuit after, at most, a chosen waiting duration.

Description

DESCRIPTION TITLE: MONITORING OF DISCHARGE CURRENT PEAKS OF A VEHICLE RECHARGEABLE BATTERY

[0001] The present invention claims priority from French application No. 2209150 filed on 09 / 13 / 2022, the content of which (text, drawings and claims) is incorporated herein by reference. Technical field of the invention

[0002] The invention relates to vehicles comprising a rechargeable battery supplying electric current to a main electrical circuit to which at least one electric motor is connected, and more specifically to the monitoring of this electric current to detect current peaks. State of the art

[0003] Some vehicles, possibly of the automobile type, include a rechargeable battery, generally called "main" (or traction), and responsible for electrically supplying, via an isolation device, a main electrical circuit (sometimes called "high voltage") to which at least one electric motor of their powertrain (or GMP) is connected. Generally, a converter, in particular responsible for electrically supplying an on-board network of the vehicle, is also connected to the main electrical circuit. Also and generally, the vehicle also includes a service battery responsible for supplying electrical energy to the on-board network, in addition to that supplied by the converter, and sometimes instead of the latter.

[0004] In the following and the preceding, the term "on-board network" means an electrical network to which electrical (or electronic) equipment (or components) consuming energy are coupled. electrical and being “non-priority” or “safety” (and therefore priority).

[0005] In some of the aforementioned vehicles, the (main) rechargeable battery is authorized to supply the main electrical circuit with a maximum electrical power which is chosen at each instant by a battery computer (associated with this rechargeable battery) according to the internal temperature and the state of charge (or "state of charge") of the latter. Generally, the battery computer includes a correspondence table (or map) establishing a correspondence between pairs of internal temperature and state of charge and maximum electrical powers.

[0006] As is known to those skilled in the art, it may happen that the discharge current supplied by the rechargeable battery to the main electrical circuit very temporarily exhibits one or more peaks corresponding to an electrical power which is much higher than the maximum electrical power authorized by the battery computer. This situation may occur, for example, when closing contactors of the isolation device of the rechargeable battery. It may cause damage to electronic power modules, the isolation device, but also to electrical components of the main electrical circuit and to protective fuses positioned upstream of these electrical components (in particular in the isolation device) to protect them against relatively high and long-lasting discharge currents.

[0007] It is recalled that these protection fuses act when the discharge current supplied becomes higher than a predefined threshold, and in the presence of a discharge current peak of an intensity much higher than this predefined threshold they immediately perform their function which then prevents the discharge current from circulating. In this situation the vehicle finds itself immobilized when its powertrain (or GMP) is all electric, which is potentially dangerous and / or penalizing for the users of this vehicle.

[0008] The invention therefore aims in particular to improve the situation, in order to avoid as far as possible that discharge current peaks cause damage to electrical equipment or that protective fuses are forced to perform their function. Presentation of the invention

[0009] For this purpose, it proposes in particular a monitoring method intended to be implemented in a vehicle comprising a rechargeable battery supplying measurable current to a main electrical circuit to which at least one electric motor is connected.

[0010] This monitoring method is characterized by the fact that it comprises a step in which, when in a discharge phase of the rechargeable battery the measured current exceeds at least one chosen threshold for at least one chosen duration associated with the latter, at least one reduction in an electrical power supplied by the rechargeable battery to the electric motor is imposed, then the rechargeable battery is isolated from the main electrical circuit after at most one chosen waiting duration.

[0011] Thanks to the invention, it is now possible to detect a discharge current peak at the output of the rechargeable battery very quickly, and to immediately take protective measures (reduction and isolation) to avoid damage to electronic power modules, electrical components of the main electrical circuit and protective fuses, and therefore to avoid the vehicle being immobilized while awaiting repair by an after-sales service.

[0012] The monitoring method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0013] - in its stage, when in a discharge phase of the rechargeable battery the measured current exceeds a first threshold chosen and a second threshold chosen strictly higher than this first threshold for at least a chosen duration associated with this second threshold, it is possible to impose the reduction of the electrical power supplied by the rechargeable battery to the electric motor, then it is possible to isolate the rechargeable battery from the main electrical circuit after at most a waiting period equal to zero;

[0014] - in its step, each chosen threshold can be a function of an internal temperature of the rechargeable battery;

[0015] - in its step, a reduction in the electrical power supplied by the rechargeable battery to the electric motor can be imposed to a value which is between 0 kW and 5 kW;

[0016] - in its step, in the event of imposition of the reduction of the electrical power supplied and isolation of the rechargeable battery, at least one additional action can be carried out in the vehicle which is chosen from a generation of an alert from a driver of the vehicle requiring a stop of the latter and a verification of the latter by an after-sales service, a recording of at least one fault code representative of a chosen highest threshold exceeded by the measured current, and an immediate reduction of an electrical power that the electric motor is authorized to supply to the rechargeable battery in an energy recovery phase when the chosen highest threshold has not been exceeded and such an energy recovery phase has just begun;

[0017] - in the presence of the last option, in its step, it is possible to impose a reduction in the electrical power that the electric motor is authorized to supply to the rechargeable battery up to a value between 0 kW and 3 kW;

[0018] - in the presence of the first option, in its stage, normal operation can be re-authorized, without reduction of electrical power supplied and without isolation, after waking up the vehicle after the latter has fallen asleep and when the measured current is lower than each chosen threshold for at least one other chosen duration and before this falling asleep the second chosen threshold had not been exceeded.

[0019] The invention also provides a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a monitoring method of the type presented above, in a vehicle comprising a rechargeable battery supplying measurable current to a main electrical circuit to which at least one electric motor is connected, in order to monitor this measured current.

[0020] The invention also proposes a monitoring device intended to equip a vehicle comprising a rechargeable battery supplying measurable current to a main electrical circuit to which at least one electric motor is connected.

[0021] This monitoring device is characterized by the fact that it comprises at least one processor and at least one memory arranged to carry out the operations consisting, when in a discharge phase of the rechargeable battery the measured current exceeds at least one chosen threshold for at least one chosen duration associated with the latter, in triggering an imposition of at least one reduction in an electrical power supplied by the rechargeable battery to the electric motor, then in triggering an isolation of the rechargeable battery from the main electrical circuit after at most one chosen waiting duration.

[0022] The invention also proposes a vehicle, possibly of the automobile type, and comprising, on the one hand, a rechargeable battery supplying measurable current to a main electrical circuit to which at least one electric motor is connected, and, on the other hand, a monitoring device of the type presented above. Brief description of the figures

[0023] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0024] [Fig. 1] schematically and functionally illustrates an exemplary embodiment of a vehicle comprising a powertrain, with an electric motor connected to a main electrical circuit to which a rechargeable battery is connected, and a monitoring device according to the invention,

[0025] [Fig. 2] schematically and functionally illustrates an exemplary embodiment of a battery calculator comprising an exemplary embodiment of a monitoring device according to the invention,

[0026] [Fig. 3] schematically illustrates an example of an algorithm implementing a monitoring method according to the invention, and

[0027] [Fig. 4] schematically illustrates in a diagram two examples of curves showing the evolution of the first and second thresholds as a function of the internal temperature of the rechargeable battery. Detailed description of the invention

[0028] The invention aims in particular to propose a monitoring method, and an associated monitoring device DS, intended to allow permanent monitoring of the discharge current id that a rechargeable battery BR of a vehicle V supplies to a main electrical circuit CEP of the latter (V), to detect discharge current peaks.

[0029] In the following, it is considered, by way of non-limiting example, that the vehicle V is of the automobile type. It is for example a car, as illustrated in Figure 1. But the invention is not limited to this type of vehicle. It relates in fact to any type of vehicle comprising a rechargeable battery connected to a main electrical circuit (or “high voltage”). Thus, it relates, for example, to land vehicles (utility vehicles, camper vans, minibuses, coaches, trucks, motorcycles, road machinery, construction machinery, agricultural machinery, leisure machinery (snowmobiles, karts), and tracked vehicles, for example), boats and aircraft.

[0030] Furthermore, it is considered in the following, by way of non-limiting example, that the vehicle V comprises a powertrain (or GMP) of the all-electric type (and therefore whose drive is provided exclusively by at least one electric motor MME). But the GMP could be of the hybrid type (thermal and electric).

[0031] Figure 1 schematically shows a vehicle V comprising an electric GMP transmission chain, an on-board network RB, a main electrical circuit CEP, a rechargeable battery BR, a converter CV, a service battery BS, and a monitoring device DS according to the invention.

[0032] The on-board network RB is an electrical power supply network to which electrical (or electronic) equipment (or components) that consume electrical energy are coupled.

[0033] The service battery BS is responsible for supplying electrical energy to the on-board network RB, in addition to that supplied by the CV converter powered by the rechargeable battery BR via the main electrical circuit CEP, and sometimes instead of this CV converter. For example, this service battery BS can be arranged in the form of a very low voltage type battery (typically 12 V, 24 V or 48 V). It is rechargeable at least by the CV current converter. It is considered in the following, by way of non-limiting example, that the service battery BS is of the 12 V Lithium-ion type.

[0034] The main (or high voltage) electrical circuit CEP is connected, on the one hand, to the rechargeable battery BR via an isolation device DI, and, on the other hand, to electronic equipment, such as the converter CV. It also allows the rechargeable battery BR to be recharged by an external power source and temporarily coupled to a charging connector CR of the vehicle V. This main electrical circuit CEP therefore comprises at least one power supply circuit C1 ensuring the coupling between the rechargeable battery BR and at least the electric motor MME and converter CV, and a recharging circuit C2 allowing the rechargeable battery BR to be recharged.

[0035] The transmission chain has a GMP which is, here, purely electric and therefore which comprises, in particular, an electric motor MME, a motor shaft AM, and a transmission shaft AT. Here, the term "electric motor" means an electric machine arranged so as to provide torque to move the vehicle V when it is supplied with electrical energy (this is then referred to as providing a positive output torque), as well as possibly recovering torque in the transmission chain (this is then referred to as providing a negative output torque).

[0036] The operation of the transmission chain (and therefore of the GMP) is supervised by a CS supervision computer.

[0037] The electric motor MME (here an electric motor) is here coupled to the rechargeable battery BR via the power supply circuit C1 of the main electrical circuit CEP, in order to be supplied with electrical energy, as well as possibly to supply this rechargeable battery BR with electrical energy, for example during a regenerative braking phase.

[0038] Furthermore, this electric motor MME is coupled to the motor shaft AM, to provide it with torque by rotating it. This motor shaft AM is here coupled to a reducer RD which is also coupled to the transmission shaft AT, itself coupled to a first train T1 (here of wheels), preferably via a differential DF.

[0039] This first train T1 is here located in the front part PW of the vehicle V. But in a variant this first train T1 could be the one which is here referenced T2 and which is located in the rear part PRV of the vehicle V.

[0040] The operation of the electric motor MME is controlled by an associated machine computer CM which receives in particular each torque instruction defined by the supervision computer CS and defining the output torque that the electric motor MME must provide or the input torque that the electric motor MME must recover.

[0041] The rechargeable battery BR here powers the electric motor MME, it constitutes a main (or traction) battery. It can, for example, include electrical energy storage cells, possibly electrochemical (for example of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type). Also for example, the main battery BP can be of the low voltage type (typically 450 V for illustration purposes). But it could be of the medium voltage or high voltage type.

[0042] Furthermore, the rechargeable battery BR is (here) associated with a battery box BB which notably includes an isolation device DI, voltage / current measuring means (not illustrated), and a battery calculator CB.

[0043] The isolation device DI is arranged so as to isolate, if necessary, the rechargeable battery BR from the entire main electrical circuit CEP, as well as possibly individually (here) from the electric motor MME and / or the converter CV. It comprises, for example, contactors (or switches), possibly based on MOSFET(s), which can each be placed in an open (or non-conducting) state or a closed (or conducting) state, as well as protective fuses.

[0044] The CB battery calculator centralizes current measurements, voltage measurements and internal temperature measurements tib (inside the rechargeable battery BR), and determines parameters of the rechargeable battery BR based on these measurements, including its internal resistance, its minimum voltage and its current state of charge (or SOC ("State Of Charge")). By Furthermore, the CB battery calculator also exchanges information with the CS supervision calculator of the GMP and the CA charging calculator.

[0045] It will be noted, as illustrated non-limitingly in Figure 1, that the CV converter can be part of a charger CH electrically connected to the charging connector CR and comprising the charging computer CA responsible within its vehicle S for at least controlling the charging of the rechargeable battery BR, whatever the mode.

[0046] It will also be noted that in the example illustrated non-limitingly in Figure 1, the vehicle V also comprises a distribution box BD to which the service battery BS, the converter CV and the on-board network RB are coupled. This distribution box BD is responsible for distributing in the on-board network RB the electrical energy stored in the service battery BS or produced by the converter CV, for the supply of the electrical components (or equipment) coupled to the on-board network RB according to power supply requests received (in particular from the supervision computer CS of the GMP).

[0047] As mentioned above, the invention proposes in particular a monitoring method intended to allow the permanent monitoring of the discharge current id that the rechargeable battery BR supplies to the main electrical circuit CEP during a discharge phase, to detect discharge current peaks. This discharge current id is measurable by a sensor fitted to the battery box BB, at the output of the positive terminal of the rechargeable battery BR. The charging current is measurable by a sensor fitted to the battery box BB, at the input of the negative terminal of the rechargeable battery BR.

[0048] This (monitoring) method can be implemented at least partially by the monitoring device DS (illustrated at least partially in Figures 1 and 2) which comprises for this purpose at least a PR1 processor, for example a digital signal processor (or DSP), and at least one MD memory. This DS monitoring device can therefore be produced in the form of a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software"). For example, it can be a microcontroller.

[0049] The MD memory is RAM in order to store instructions for the implementation by the processor PR1 of at least part of the monitoring method. The processor PR1 may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. An integrated (or printed) circuit is understood to mean any type of device capable of carrying out at least one electrical or electronic operation.

[0050] In the example illustrated non-limitingly in Figures 1 and 2, the monitoring device DS is part of the battery computer CB. This is advantageous because it is the latter (CB) which controls the electrical power pef which is supplied by the rechargeable battery BR and the isolation device DI. But this is not obligatory. Indeed, the monitoring device DS could include its own dedicated computer, which is then coupled to the battery computer CB, or could be part of another on-board computer than the latter (CB), such as for example the supervision computer CS.

[0051] As illustrated non-limitingly in Figure 3, the (monitoring) method according to the invention comprises a step 10-30 which is implemented when the vehicle V is awake and therefore its rechargeable battery BR is capable of supplying a discharge current id to the main electrical circuit CEP.

[0052] Step 10-30 of the method comprises a sub-step 20 in which, when in a discharge phase of the rechargeable battery BR the measured discharge current id exceeds at least one threshold sj (j = 1 or 2) chosen for at least one duration dj chosen and associated with the latter (sj), the monitoring device is imposed DS triggers the imposition of at least one reduction in the electrical power pef supplied by the rechargeable battery BR to the electric motor MME. Then, the rechargeable battery BR is isolated (the monitoring device DS triggers the isolation of) from the main electrical circuit CEP after at most a chosen waiting time da. It should be noted that in the example illustrated, the isolation of the rechargeable battery BR is done by acting on one or more contactors (or switches) of the isolation device DI.

[0053] Thus, by judiciously choosing each threshold sj and each duration dj, it is possible to very quickly detect a discharge current peak at the output of the rechargeable battery BR, and immediately take protective measures (reduction and isolation) likely to protect the electronic power modules, the isolation device DI, the electrical components of the main electrical circuit CEP and the protective fuses positioned upstream of these electrical components (in particular in the isolation device DI). This prevents their damage, and in particular the protective fuses from acting, which prevents the vehicle V from being immobilized with no other option than to be repaired by an after-sales service when its powertrain is all electric. The users of the vehicle V are therefore now less penalized (or even almost more penalized as we will see later), without reducing their safety or that of the vehicle V.

[0054] It is important to note that the invention can use either a single first threshold s1 (j = 1), or a first threshold s1 and a second threshold s2 (j = 2) strictly greater than the first threshold s1. The second alternative makes it possible to have a graduation of the protection measures which are taken according to the largest threshold sj which is exceeded for at least the associated duration dj.

[0055] For example, in step 10-30 each duration dj can be between 300 ms and 800 ms. As an illustrative example, each duration dj can be equal to 500 ms. But other values ​​can be used for each duration dj, the objective being to avoid damage to electronic components (of all kinds) caused by excessively long exposure to a discharge current peak. In particular, in the presence of first s1 and second s2 thresholds, different first d1 and second d2 durations can be used (in this case, d1 can be greater than d2 because exceeding only the first threshold s1 is likely to cause damage more slowly than exceeding the second threshold s2). For example, the value of each duration dj can be chosen during the development phase of a vehicle similar to vehicle V.

[0056] Also for example, and as illustrated non-limitingly in Figure 3, step 10-30 may comprise a sub-step 10 in which one (the monitoring device DS) begins by comparing the measured discharge current id with each threshold sj used. If the measured discharge current id is less than or equal to each threshold sj, one returns to perform sub-step 10 with the following measured discharge current id. On the other hand, if the measured discharge current id is strictly greater than at least one threshold sj, one (the monitoring device DS) performs sub-step 20 in order to take protective measures (at least the reduction of the electrical power pef supplied by the rechargeable battery BR to the electric motor MME, and the more or less rapid isolation of the rechargeable battery BR from the main electrical circuit CEP).

[0057] When using the first threshold s1 (associated with the first duration d1) and the second threshold s2 (associated with the second duration d2), the option described below can be implemented.

[0058] In sub-step 20 of step 10-30, when in a discharge phase of the rechargeable battery BR the measured discharge current id exceeds the first s1 and second s2 thresholds chosen for at least the second duration d2 chosen, it is possible to impose (the monitoring device DS can trigger the imposition of) at least the reduction of the electrical power pef (supplied by the rechargeable battery BR to the electric motor MME). Then, the rechargeable battery BR can be isolated (the monitoring device DS can trigger the isolation of) from the main electrical circuit CEP after at most a waiting time da which is equal to zero. In other words, the isolation of the rechargeable battery BR is done immediately after the detection of a discharge current peak having an intensity greater than that of the second threshold s2, so as to protect the aforementioned electronic components as quickly as possible because exceeding the second threshold s2 is likely to cause damage more quickly than exceeding the first threshold s1.

[0059] It will be understood that in the presence of this option, when in a discharge phase of the rechargeable battery BR the measured discharge current id is between the first s1 and second s2 thresholds chosen for at least the first duration d1 chosen, the reduction of the electrical power pef (supplied by the rechargeable battery BR to the electric motor MME) is imposed (the monitoring device DS triggers the imposition). Then, the rechargeable battery BR can be isolated (the monitoring device DS can trigger the isolation of) the rechargeable battery from the main electrical circuit CEP after at most the waiting time da which is non-zero. In other words, the isolation of the rechargeable battery BR is done at the latest after the expiry of the waiting time da triggered upon detection of a discharge current peak having an intensity greater than that of the first threshold s1 but less than that of the second threshold s2.

[0060] The waiting time da corresponds here to the time during which the battery calculator CB waits for a response from the supervision calculator CS to a request for authorization to isolate the rechargeable battery BR by means of the isolation device DI, once the reduction of the electrical power pef supplied by the rechargeable battery BR has been carried out. As soon as the battery calculator CB receives the authorization from the supervision calculator CS, it triggers the isolation of the rechargeable battery BR by configuring appropriately the isolation device DI. On the other hand, if at the end of the waiting time da the battery calculator CB has not received authorization from the supervision calculator CS, it triggers on its own initiative the isolation of the rechargeable battery BR by appropriately configuring the isolation device DI.

[0061] It should be noted that when the measured discharge current id is greater than the second threshold s2 for at least the second duration d2, the battery calculator CB triggers the isolation of the rechargeable battery BR on its own initiative by appropriately configuring the isolation device DI, without having requested authorization from the supervision calculator CS, to save time.

[0062] The option described above therefore allows for a graduation of the protection measures which are taken according to the highest threshold sj which is exceeded for at least the duration dj associated.

[0063] It will also be noted that it is preferable that in sub-step 10 of step 10-30 each threshold sj chosen is a function of the internal temperature tib of the rechargeable battery BR. Indeed, each threshold sj is chosen so as to protect in particular the protective fuses contained in the battery case BB and having a resistance which varies according to their temperature. Here, this temperature is considered to be the internal temperature tib of the rechargeable battery BR. In this case, each threshold sj chosen does not depend on the state of charge of the rechargeable battery BR, but only on the internal temperature tib.

[0064] The diagram in Figure 4 schematically illustrates two examples of curves showing the evolution of the first s1 and second s2 thresholds as a function of the internal temperature tib (in °C) of the rechargeable battery BR. These evolution curves can be defined by equations or by correspondence tables (sj / tib) obtained in the laboratory or during tests and stored in the monitoring device DS.

[0065] But in an alternative embodiment, each threshold sj could be constant (independent of the internal temperature tib).

[0066] For example, in sub-step 20 of step 10-30, a reduction in the electric power pef (supplied by the rechargeable battery BR to the electric motor MME) may be imposed (the monitoring device DS may trigger the imposition of a) down to a limit value vl 1 which is between 0 kW and 5 kW. As an illustrative example, this limit value vl1 may be equal to 0 kW (which means that the rechargeable battery BR is prohibited from supplying any electric power pef to the electric motor MME). But other limit values ​​vl1 may be used. For example, this limit value vl1 may be chosen during the development phase of a vehicle similar to vehicle V.

[0067] This reduction in electrical power pef is preferably immediate. But it could be gradual, possibly linear, and implemented over a very short time interval.

[0068] Also for example, in sub-step 20, in the event of a decision to impose the reduction of the supplied electrical power pef and isolation of the rechargeable battery BR, it is also possible to carry out (the monitoring device DS can trigger the carrying out) in the vehicle V at least one complementary action chosen from:

[0069] - generation of an alert from the driver of vehicle V requiring a stop of vehicle V and a check of the latter (V) in an after-sales service,

[0070] - a record of at least one fault code representative of the highest threshold sj chosen having been exceeded by the measured discharge current id, and

[0071] - an immediate reduction in the electrical power pea that the electric motor MME is authorized to supply to the rechargeable battery BR in an energy recovery phase when the highest threshold sj chosen has not been exceeded and such an energy recovery phase has just begun.

[0072] The driver of the vehicle V may be alerted, for example, by lighting up a "stop" type alarm (or "warning") light or a service light representing a need to go to an after-sales service, for example present in the dashboard, and / or a message displayed on at least one screen of the vehicle V (for example the dashboard or a central instrument panel) or on the screen of a smartphone of the driver, and / or broadcast by at least one loudspeaker of the vehicle V or of this smartphone.

[0073] The recording of at least one fault code representative of the highest threshold sj having been exceeded is intended to facilitate understanding of the origin of protective measures (reduction(s) and isolation) taken in the vehicle V by an after-sales service technician, and to enable this technician to resolve the problem and inform the user of the vehicle V of the origin of the problem that has occurred.

[0074] The immediate reduction of the electric power pea (which the electric motor MME is authorized to supply to the rechargeable battery BR) is intended to prevent the latter from being recharged (BR) in the event that the driver suddenly decides to trigger an energy recovery phase while the vehicle V is moving at least partly thanks to the torque produced by the electric motor MME with the electric power pef supplied by the rechargeable battery BR.

[0075] For example, in sub-step 20 of step 10-30, a reduction in the electrical power pea (which the electric motor MME is authorized to supply to the rechargeable battery BR) can be imposed (the monitoring device DS can trigger the imposition of a) down to a limit value vl2 which is between 0 kW and 3 kW. As an illustrative example, this limit value vl2 can be equal to 0 kW (which means that the motor is prohibited electric MME to provide the least electrical power pea to the rechargeable battery BR). But other limit values ​​vl2 can be used. For example, this limit value vl2 can be chosen during the development phase of a vehicle similar to vehicle V.

[0076] In an alternative embodiment, the reduction in the electrical power pea could be progressive, possibly linear, and implemented over a very short time interval.

[0077] Also for example, and as illustrated non-limitingly in Figure 3, step 10-30 may comprise a sub-step 30 in which one (the monitoring device DS) may re-authorize normal operation of the vehicle V, without reduction of the electrical power supplied and without isolation. In this case, the re-authorization is preferably given after waking up the vehicle V after it has fallen asleep and when the measured discharge current id is lower than each threshold sj chosen for at least one other duration d'j chosen, but also when before this falling asleep the second threshold s2 chosen had not been exceeded.

[0078] It will be understood that in the presence of this last sub-option, when before falling asleep the second threshold s2 chosen had been exceeded during the second duration d2, normal operation of the vehicle V is not re-authorized, without reduction of electrical power supplied and without isolation. It is then imperative that a technician from an after-sales service examines the vehicle V, and carries out any repairs before updating at least one computer of the vehicle V so that the latter (V) can operate normally again. Re-authorization is therefore only possible on condition that the vehicle V has fallen asleep ("ignition off") after exceeding only the first threshold s1 during the first duration d1.

[0079] Preferably, after a re-authorization one also stops generating a (the DS monitoring device stops triggering the generation of an alert for the user (when this additional action is planned). Of course, if after a reauthorization one of the thresholds sj is exceeded again, new protection measures corresponding to this exceeded threshold sj are again taken by the DS monitoring device.

[0080] For example, in step 10-30 each other duration d'j can be between 300 ms and 800 ms. As an illustrative example, each other duration d'j can be equal to 500 ms. But other values ​​can be used for each other duration d'j. In particular, in the presence of first s1 and second s2 thresholds, one can use first d'1 and second d'2 of different durations. For example, the value of each other duration d'j can be chosen during the development phase of a vehicle similar to vehicle V.

[0081] It will also be noted, as illustrated non-limitingly in Figure 2, that the battery calculator CB (or the calculator of the monitoring device DS) may also comprise a mass memory MM1, in particular for storing the current discharge current id and the possible current internal temperature tib, as well as any intermediate data involved in all its calculations and processing. Furthermore, this battery calculator CB (or the calculator of the monitoring device DS) may also comprise an input interface IE for receiving at least the current discharge current id and the possible current internal temperature tib, to use them in calculations or processing, possibly after having shaped and / or demodulated and / or amplified them, in a manner known per se, by means of a digital signal processor PR2.In addition, this battery calculator CB (or the calculator of the monitoring device DS) can also include an output interface IS, in particular to deliver a message (or order) for reducing pef or pea, a message (or order) for isolating the rechargeable battery BR, a message (or order) for ending isolation of the rechargeable battery BR, a message (or order) requesting authorization for isolating the rechargeable battery BR, a possible. user alert message, and a possible message containing a fault code.

[0082] It will also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when executed by processing means of the electronic circuit (or hardware) type, such as for example the processor PR1, is capable of implementing the monitoring method described above to monitor the discharge current id that the rechargeable battery BR supplies to the main electrical circuit CEP, to detect discharge current peaks.

Claims

CLAIMS

1. Monitoring method for a vehicle (V) comprising a rechargeable battery (BR) supplying measurable current to a main electrical circuit (CEP) to which at least one electric motor (MME) is connected, characterized in that it comprises a step (10-30) in which, when in a discharge phase of said rechargeable battery (BR) said measured current exceeds at least one chosen threshold for at least one chosen duration associated with the latter, at least one reduction of an electrical power supplied by said rechargeable battery (BR) to said electric motor (MME) is imposed, then said rechargeable battery (BR) is isolated from said main electrical circuit (CEP) after at most one chosen waiting duration.

2. Method according to claim 1, characterized in that in said step (10-30), when in a discharge phase of said rechargeable battery (BR) said measured current exceeds a first chosen threshold and a second chosen threshold strictly greater than said first threshold for at least a chosen duration associated with this second threshold, said reduction in the electrical power supplied by said rechargeable battery (BR) to said electric motor (MME) is imposed, then the rechargeable battery (BR) is isolated from said main electrical circuit (CEP) after at most a waiting period equal to zero.

3. Method according to claim 1 or 2, characterized in that in said step (10-30) each chosen threshold is a function of an internal temperature of said rechargeable battery (BR).

4. Method according to one of claims 1 to 3, characterized in that in said step (10-30) a reduction of said electrical power supplied by said rechargeable battery (BR) to said electric motor (MME) is imposed down to a value between 0 kW and 5 kW.

5. Method according to one of claims 1 to 4, characterized in that in said step (10-30), in the event of imposing said reduction in the electrical power supplied and isolating said rechargeable battery (BR), at least one additional action is carried out in said vehicle (V) chosen from generating an alert from a driver of said vehicle (V) requiring a stop of said vehicle (V) and a check of the latter (V) by an after-sales service, recording at least one fault code representative of a chosen highest threshold exceeded by said measured current, and an immediate reduction of an electrical power that said electric motor (MME) is authorized to supply to said rechargeable battery (BR) in an energy recovery phase when said chosen highest threshold has not been exceeded and such an energy recovery phase has just begun.

6. Method according to claim 5, characterized in that in said step (10-30) a reduction is imposed on said electrical power that said electric motor (MME) is authorized to supply to said rechargeable battery (BR) down to a value between 0 kW and 3 kW.

7. Method according to claim 2 taken in combination with one of claims 3 to 6, characterized in that in said step (10-30) normal operation is re-authorized, without reduction of electrical power supplied and without isolation, after waking up said vehicle (V) after the latter (V) has gone to sleep and when said measured current is lower than each chosen threshold for at least one other chosen duration and that before said sleep said second chosen threshold had not been exceeded.

8. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the monitoring method according to one of claims 1 to 7, in a vehicle (V) comprising a rechargeable battery (BR) supplying measurable current to a main electrical circuit (CEP) to which at least one electric motor (MME) is connected, for monitoring said measured current.

9. Monitoring device (DS) for a vehicle (V) comprising a rechargeable battery (BR) supplying measurable current to a main electrical circuit (CEP) to which at least one is connected electric motor (MME), characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting, when in a discharge phase of said rechargeable battery (BR) said measured current exceeds at least one chosen threshold for at least one duration chosen and associated with the latter, in triggering an imposition of at least one reduction of an electrical power supplied by said rechargeable battery (BR) to said electric motor (MME), then in triggering an isolation of said rechargeable battery (BR) from said main electrical circuit (CEP) after at most one waiting duration chosen.

10. Vehicle (V) comprising a rechargeable battery (BR) supplying measurable current to a main electrical circuit (CEP) to which at least one electric motor (MME) is connected, characterized in that it further comprises a monitoring device (DS) according to claim 9.

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