FR3131637A1 - MONITORING A MAIN VEHICLE BATTERY FOR THE DETECTION OF THERMAL RUNAWAY - Google Patents

Abstract

A method monitors a main battery fitted to a vehicle and associated with a battery computer communicating with a supervision computer supervising the performance of actions in the vehicle. This method comprises a step (10-60) in which, in the event of detection of a thermal runaway potential in the main battery, the battery computer alerts the supervision computer, then the latter supervises the alert of at least one vehicle user, and, when the supervision computer is informed of a predefined event relating to the main battery after the user has been alerted, the supervision computer supervises the carrying out of an emergency procedure in the vehicle. Picture 3

Description

MONITORING A VEHICLE’S MAIN BATTERY FOR DETECTION OF THERMAL RUNWAY Technical field of the invention

The invention concerns vehicles comprising a main (or traction) battery, and more specifically the monitoring of such batteries with a view to detecting thermal runaway.

State of the art

Certain vehicles, possibly of the automobile type, include a so-called “main” (or traction) battery, possibly cellular, and responsible for supplying electric current to an on-board network via a converter and an electric drive machine.

Furthermore, in what follows and what precedes, the term “on-board network” means an electrical supply network to which electrical (or electronic) equipment (or components) consuming electrical energy are coupled.

As those skilled in the art know, many main batteries include internal sensors (measuring in particular an internal temperature, an internal pressure, a voltage, and a current), and are associated with a battery calculator responsible for determining their internal resistance, their minimum voltage, their state of charge (or SOC (“State Of Charge”)) and their state of health (or SOH (“State Of Health”)).

Sometimes, and as described in particular in patent documents EP-B1 2446286 and EP-A1 3686050, the battery calculator is also responsible for analyzing the measurements provided by the internal sensors in order to detect a potential thermal runaway in the main battery. , for example linked to strong internal heating or the start of an internal fire. Typically thermal runaway occurs when the local temperature is between 150°C and 180°C. When the battery computer makes such a detection it alerts a vehicle supervision computer which is then responsible for supervising at least the alert of one vehicle user. Note that this alert can be done by displaying an alert message or lighting a warning light on at least one screen of the vehicle (for example on the dashboard) and/or by broadcasting an audio message or 'an audible signal through at least one vehicle speaker. The user's alert is intended to ask him to move the vehicle to a clear location as quickly as possible and then to evacuate the vehicle after switching off the ignition.

The current mode of main battery monitoring has several disadvantages. In fact, the alert can be stressful for the user and therefore can prevent them from reacting correctly and quickly. Furthermore, the user's alert may be accompanied by internal actions likely to completely and definitively isolate the main battery from the vehicle's other electrical equipment (and in particular its electric motor) and/or to stop the fire. internal by spraying or internal diffusion of a product making it unusable, which prevents any recirculation of the vehicle and therefore can annoy the user. However, it frequently happens that the detected incident (strong heating or fire) is purely local, for example in a single cell or a single module of cells, and that its duration is very short due to a lack of internal propagation. It can also happen that the battery computer alerts the supervision computer by mistake or because it has received erroneous measurements from internal sensors. It will be understood that in this type of situation where the thermal runaway is very localized and short or non-existent, the actions taken in the vehicle are poorly adapted to the real situation, or even inappropriate.

The invention therefore aims in particular to improve the situation by triggering actions adapted to the real situation in the main battery.

Presentation of the invention

It proposes in particular for this purpose a monitoring method, on the one hand, intended to be implemented in a vehicle comprising a main battery associated with a battery computer communicating with a supervision computer supervising the performance of actions in the vehicle , and, on the other hand, comprising a step in which, in the event of detection of a potential thermal runaway in the main battery, the battery computer alerts the supervision computer, then the latter supervises the alert of at least a vehicle user.

This monitoring process is characterized by the fact that in its step, when the supervision computer is informed of a predefined event relating to the main battery after the user alert, the supervision computer supervises the carrying out of a emergency procedure in the vehicle.

Thanks to this predefined event which constitutes confirmation of the existence of a thermal runaway, we avoid carrying out additional action(s) when the thermal runaway is very localized and short, but also when the temperature calculator battery transmitted a dedicated alert message in error or because it received erroneous measurements from internal sensors. In other words, the emergency procedure is carried out when it is confirmed that the main battery is experiencing an effective thermal runaway.

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

- in its step the supervision computer can be informed of the predefined event in the event of an interruption in communication with the battery computer;

- alternatively, in its step the supervision computer can be informed of the predefined event in the event of reception of a temperature measurement taken outside the main battery and greater than a chosen threshold;

- in its stage the supervised emergency procedure may include at least one action chosen from a group including another alert from the user, an opening of at least one window of the vehicle capable of allowing outside air into a passenger compartment of the vehicle, interruption of ventilation of the passenger compartment with outside air, unlocking of vehicle doors allowing access to the passenger compartment, stopping of electrical power supplied by the main battery, stopping a recharge phase of the main battery, isolating the main battery from any electrical equipment of the vehicle, spraying or diffusing product into the main battery, emergency braking, activation of hazard lights of the vehicle, taking control of a steering column and a speed of movement of the vehicle capable of imposing on the latter an emergency stopping trajectory.

The invention also proposes 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 of that presented above to monitor a main battery fitted to a vehicle comprising a battery computer associated with this main battery and communicating with a supervision computer supervising the performance of actions in the vehicle.

The invention also proposes a monitoring device, on the one hand, intended to equip a vehicle comprising a main battery associated with a battery computer communicating with a supervision computer supervising the performance of actions in the vehicle, and, on the other hand, comprising at least one processor and at least one memory arranged to carry out the operations consisting, in the event of detection of a potential thermal runaway in the main battery by the battery computer, in triggering supervision by the supervision computer of an alert from at least one user of the vehicle.

This monitoring device is characterized by the fact that its processor and memory are also arranged to carry out operations consisting, in the event of the occurrence of a predefined event relating to the main battery after the user alert, of triggering supervision by the computer for supervising an emergency procedure in the vehicle.

The invention also proposes a supervision computer, on the one hand, suitable for supervising the performance of actions in a vehicle comprising a main battery associated with a battery computer, and suitable for communicating with the latter, and, on the other hand part, comprising a monitoring device of the type presented above.

The invention also proposes a vehicle, possibly of the automobile type, and comprising, on the one hand, a main battery associated with a battery computer, and, on the other hand, either a supervision computer, suitable for supervising the implementation of actions in the vehicle and to communicate with the main battery, and a monitoring device of the type of that presented above, or a supervision computer of the type of that presented above.

Brief description of the figures

Other characteristics and advantages of the invention will appear on examination of the detailed description below, and the appended drawings, in which:

schematically and functionally illustrates an exemplary embodiment of a vehicle comprising a GMP, with an electric motor powered by a main battery, a supervision computer and a monitoring device according to the invention,

schematically and functionally illustrates an exemplary embodiment of a supervision computer comprising a monitoring device according to the invention, and

schematically illustrates an example of an algorithm implementing a monitoring method according to the invention.

Detailed description of the invention

The invention aims in particular to propose a monitoring method, and an associated DS monitoring device, intended to allow the monitoring of a main battery BP forming part of a vehicle V, in order to detect confirmed thermal runaways.

In what follows, we consider, by way of non-limiting example, that the vehicle V is of the automobile type. This is for example a car (as illustrated in the ). But the invention is not limited to this type of vehicle. It concerns any type of vehicle comprising a main (or traction) cellular battery. Thus, it concerns, for example, land vehicles (utility vehicles, motorhomes, minibuses, coaches, trucks, motorcycles, road machinery, construction machinery, agricultural machinery, leisure machinery (snowmobile, kart), and road machinery. caterpillar(s), for example), boats, and aircraft.

Furthermore, we consider in what follows, by way of non-limiting example, that the vehicle V comprises a powertrain (or GMP) of all-electric type (and therefore whose traction is ensured exclusively by at least one electric driving machine MRS). But the GMP could be of hybrid type (thermal and electric).

We have schematically represented on the a vehicle V (here a vehicle) comprising in particular a passenger compartment H which can accommodate at least one user, an electric driving machine MME forming part of a GMP of a transmission chain, a main (or traction) battery BP associated with a CB battery calculator, a CS supervision calculator, and a DS monitoring device according to the invention.

The supervision computer CS is in particular arranged so as to supervise the performance of actions in the vehicle V. In addition, it communicates with the battery computer CB directly or indirectly, for example via an on-board communication network, possibly of the multiplexed type. .

The electric driving machine MME (here an electric motor) is coupled to the main battery BP, in order to be supplied with electrical energy, as well as possibly to supply this main battery BP with electrical energy during a regenerative braking phase. It is coupled to a motor shaft to provide it with torque by rotational drive, and this motor shaft is coupled (possibly via a reduction gear) to a transmission shaft which is itself coupled to a train (here of wheels), of preferably via a differential. For example, this train can be located in the front part of vehicle V. But in a variant it could be located in the rear part of vehicle V.

The main BP battery can, for example, include electrical energy storage cells. For example, these cells can be electrochemical, and in this case they can be of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type, for example. Note that these cells can be grouped within modules connected in series, each module comprising at least one cell (and possibly several connected in series).

Also for example, the main BP battery can be of the low voltage type (typically 450 V for illustration purposes). But it could be medium voltage or high voltage.

Furthermore, the main battery BP is associated with the battery calculator CB which can be part of a battery box also comprising an isolation device and voltage/current/pressure/temperature measuring means.

In addition, the main battery BP comprises internal sensors C1 responsible for measuring in particular at least one internal temperature, at least one internal pressure, at least one voltage, and at least one current, and providing its measurements to the battery calculator CB so that he analyzes them and uses them to determine if there is a potential thermal runaway in the main LP battery. This last determination not being the subject of the invention it will not be described here.

The isolation device is arranged so as to isolate the main battery BP from at least one piece of electrical equipment of the vehicle V, and in particular from the electric motive machine MME, when the battery calculator CB requests it. For example, this isolation device may include protection fuses and contactors (or switches) based on MOSFET(s) which can each take an open (or non-conducting) state and a closed (or conducting) state.

The CB battery calculator centralizes the voltage and current measurements and determines the current parameters of the main battery BP based on these measurements, and in particular its internal resistance, its minimum voltage, its state of charge (or SOC)) and his state of health (or SOH). Furthermore, the CB battery calculator exchanges information and messages with the CS supervision calculator.

As mentioned above, the invention notably proposes a monitoring method intended to enable monitoring of the main BP battery of vehicle V, in order to detect confirmed thermal outbursts.

This (monitoring) method can be implemented at least partially by the monitoring device DS (illustrated in Figures 1 and 2) which comprises for this purpose at least one processor PR1, for example a digital signal (or DSP ("DSP") Digital Signal Processor")), 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.

The memory MD is RAM in order to store instructions for the implementation by the processor PR1 of at least part of the monitoring process. The processor PR1 may include integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or non-wired connections. By integrated (or printed) circuit we mean any type of device capable of performing at least one electrical or electronic operation.

In the example illustrated without limitation in Figures 1 and 2, the monitoring device DS is part of the supervision computer CS. But this is not obligatory. Indeed, the monitoring device DS could include its own dedicated computer, which is then coupled to the supervision computer CS.

As illustrated without limitation on the , the (monitoring) method, according to the invention, comprises a step 10-60 which is implemented in the vehicle V as soon as the battery calculator CB is supplied with electrical energy (for example by a utility battery).

This step 10-60 includes a sub-step 10 in which the battery calculator CB analyzes the measurements provided by the internal sensors C1 in order to determine if there is a potential thermal runaway in the main battery BP. If so, and therefore in the event of detection of a potential thermal runaway in the main battery BP, the battery computer CB alerts the supervision computer CS in a sub-step 20 of step 10-60. This alert is done by transmitting an alert message dedicated to the CS supervision computer.

Then, in a sub-step 30 of step 10-60, the supervision computer CS supervises an alert from at least one user of the vehicle V following receipt of the dedicated alert message. It will be understood that it is the monitoring device DS (and more precisely the operations carried out by its processor PR1 and memory MD) which triggers the supervision of the user alert by the supervision computer CS, after receipt of the dedicated alert message.

Preferably, this alert is only intended to warn the user of a problem detected with the main battery BP so that they reduce the speed of the vehicle V. This type of alert is in fact less stressful for the user. the user as an alert intended to ask him to place the vehicle V in a clear location as quickly as possible then to evacuate the vehicle V after switching off the ignition.

Note that this alert can be done by displaying an alert message or lighting a warning light on at least one screen of the vehicle V (for example on the dashboard) or on the screen of a smartphone ( or “smartphone”) of the user, and/or by broadcasting a sound message or a sound signal through at least one speaker of the vehicle V or this smartphone.

Then, in a sub-step 40 of step 10-60, when the supervision computer CS is informed of a predefined event relating to the main battery BP after it has alerted the user, the supervision computer CS supervises the carrying out of an emergency procedure in the vehicle V in a sub-step 50 of step 10-60, because it considers that the main battery BP is the subject of a confirmed thermal runaway (and therefore potentially dangerous for vehicle V and its users). In other words, the emergency procedure is carried out when it is confirmed that the main LP battery is subject to an effective thermal runaway.

It will be understood that it is the monitoring device DS (and more precisely the operations carried out by its processor PR1 and memory MD) which trigger(s) the supervision of the execution of the emergency procedure by the supervision computer CS in the substep 50.

It will also be understood that in sub-step 40 if the supervision computer CS is not informed of a predefined event relating to the main battery BP, for example after the expiration of a chosen duration having started after the alert of the The user considers that the main battery BP is not the subject of a confirmed thermal runaway and therefore the monitoring process ends in a sub-step 60.

For example, the chosen duration can be between 5 mins and 60 mins (because it depends on the type of the main BP battery and its inter-cell and inter-module insulation. As an illustrative example, the chosen duration can be equal to 10 minutes. But other chosen durations can be used.

The occurrence of the predefined event constitutes confirmation of the existence of a thermal runaway which justifies the carrying out of additional action(s) in the vehicle V, likely to secure it and/or to secure each user present in his passenger compartment H. This makes it possible to avoid carrying out additional action(s) when the thermal runaway is very localized and short, but also when the CB battery computer has transmitted an alert message dedicated by mistake or because it received erroneous measurements from internal sensors C1.

At least two predefined events can be considered.

For example, in substep 40 of step 10-60 the supervision computer CS can be informed of the predefined event in the event of interruption of communication with the battery computer CB. Such an interruption results in fact from damage to the battery computer CB and/or the communication interface of the latter (CB) and/or the bus of the communication network which couples it to the supervision computer CS, due to a worsening of the incident occurring in the main BP battery (for example a sharp increase in temperature and/or propagation of the internal fire). Consequently, when the CS supervision computer and CB battery computer can no longer communicate after transmission of the dedicated alert message, we are certain that there is a confirmed thermal runaway in the main battery BP.

Alternatively, it is possible, as illustrated non-limitatively in the add to the main battery BP, for example on an external face of the latter (BP), a temperature sensor C2 responsible for measuring the temperature outside the main battery BP. In this variant, in sub-step 40 of step 10-60 the supervision computer CS is informed of the predefined event in the event of reception of a temperature measurement, carried out outside the main battery BP by the temperature sensor C2, and greater than a chosen threshold.

For example, this chosen threshold can be between 80°C and 150°C. As an illustrative example, the chosen threshold can be equal to 100°C. But other chosen thresholds can be used.

It will be understood that in this variant, when the temperature outside the main BP battery has exceeded the chosen threshold, this indicates that the incident occurring in the main BP battery has worsened (for example due to propagation of the internal fire), and therefore we are certain that there is a confirmed thermal runaway in the main LP battery.

Note that within the same vehicle V the two predefined events described above can be taken into account. In this case, if at least one of these two predefined events occurs during substep 40, then the emergency procedure is triggered.

It should also be noted that in sub-step 50 of step 10-60 the supervised emergency procedure may include at least one action chosen from:

- another alert from the user (for example to ask him to place the vehicle V in a clear location as quickly as possible then to evacuate the vehicle V after switching off the ignition, if this has not already been done subject of the first alert of sub-step 30),

- an opening of at least one window FV of vehicle V capable of allowing outside air into the passenger compartment H of vehicle V (to evacuate potentially toxic gases having entered the passenger compartment H to the outside),

- an interruption of the ventilation of the passenger compartment H with outside air (we then operate without renewing the air in the passenger compartment H or we ventilate only with recirculated air to avoid the entry of toxic gases present in the outside air surrounding the vehicle V),

- unlocking of the PV doors of the vehicle V allowing access to the passenger compartment H (to facilitate the evacuation of users from this passenger compartment H),

- a shutdown of the electrical power supplied by the main battery BP (in particular to the electric motor MME),

- stopping a charging phase of the main BP battery,

- isolation of the main battery BP from all electrical equipment of the vehicle V,

- spraying or diffusing product into the main LP battery (to try to stop the internal fire (or the propagation of the latter) and/or lower the internal temperature),

- emergency braking (to replace the driving user, particularly in the absence of a new alert from this user),

- activation of the hazard lights of vehicle V (to alert third parties of a danger),

- taking control of the steering column and the speed of movement of the vehicle V capable of imposing on the latter (V) an emergency stopping trajectory (to replace the user driver, in particular by absence of new alert from this user).

For example, the other alert to the user of vehicle V can be done by displaying another alert message or lighting a warning light (possibly with a different color (typically red instead of orange) ) on at least one screen of the vehicle V (for example the dashboard) or on the screen of the user's smartphone, and/or by broadcasting another sound message or another sound signal by the least one speaker of the vehicle V or this smartphone.

Also for example, the isolation of the main battery BP (in particular of the electric motor machine MME) is preferably done via the isolation device, for example by placing its contactors (or switches) in their open state.

Note also, as illustrated non-limitatively in the , that the CB battery calculator (or the dedicated calculator of the DS monitoring device) can also include a mass memory MM1, in particular for the temporary storage of the content of the dedicated alert message and the possible outside temperature measurement, and possible intermediate data involved in all its calculations and processing. Furthermore, this CB battery calculator (or the dedicated calculator of the DS monitoring device) can also include an IE input interface for receiving at least the dedicated alert message and the possible outside temperature measurement for use their content in calculations or processing, possibly after having formatted and/or demodulated and/or amplified it, in a manner known per se, by means of a digital signal processor PR2. In addition, this CB battery calculator (or the dedicated calculator of the DS monitoring device) can also include an IS output interface, in particular to deliver electrical isolation or spraying or diffusion of product or shutdown orders. phase of recharging or reduction of the electrical power supplied by the LP battery or of emergency braking or of taking control of the steering column and the speed of movement or of activating the hazard lights, or messages to display and/or distribute.

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 main battery BP of the vehicle V, in order to detect confirmed thermal runaways.

Claims (9)

Monitoring method for a vehicle (V) comprising a main battery (BP) associated with a battery computer (CB) communicating with a supervision computer (CS) supervising the performance of actions in said vehicle (V), said method comprising a step (10-60) in which, in the event of detection of a potential thermal runaway in said main battery (BP), said battery computer (CB) alerts said supervision computer (CS), then the latter (CS) supervises the alert of at least one user of said vehicle (V), characterized in that in said step (10-60), when said supervision computer (CS) is informed of a predefined event relating to said main battery ( BP) after alerting said user, said supervision computer (CS) supervises the carrying out of an emergency procedure in said vehicle (V). Method according to claim 1, characterized in that in said step (10-60) said supervision computer (CS) is informed of said predefined event in the event of interruption of communication with said battery computer (CB). Method according to claim 1, characterized in that in said step (10-60) said supervision computer (CS) is informed of said predefined event in the event of receipt of a temperature measurement taken outside of said main battery ( BP) and greater than a chosen threshold. Method according to one of claims 1 to 3, characterized in that in said step (10-60) said supervised emergency procedure comprises at least one action chosen from a group comprising another alert from said user, an opening of at least one least one window of said vehicle (V) capable of allowing outside air to enter a passenger compartment (H) of said vehicle (V), an interruption of ventilation of said passenger compartment (H) with outside air, an unlocking of doors of said vehicle (V) allowing access to said passenger compartment (H), stopping an electrical power supplied by said main battery (BP), stopping a recharge phase of said main battery (BP), isolation of said main battery (BP) of any electrical equipment of said vehicle (V), a spraying or diffusion of product in said main battery (BP), emergency braking, activation of hazard lights of said vehicle (V) , taking control of a steering column and a speed of movement of said vehicle (V) capable of imposing on the latter (V) an emergency stopping trajectory. 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 4 for monitoring a main battery (BP ) equipping a vehicle (V) comprising a battery computer (CB) associated with said main battery (BP) and communicating with a supervision computer (CS) supervising the performance of actions in said vehicle (V). Monitoring device (DS) for a vehicle (V) comprising a main battery (BP) associated with a battery computer (CB) communicating with a supervision computer (CS) supervising the performance of actions in said vehicle (V), said device (DS) comprising at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting, in the event of detection of a potential thermal runaway in said main battery (BP) by said battery calculator (CB), to trigger supervision by said supervision computer (CS) of an alert from at least one user of said vehicle (V), characterized in that said processor (PR1) and memory (MD) are further arranged to carry out the operations consisting, in the event of the occurrence of a predefined event relating to said main battery (BP) after the alert of said user, in triggering supervision by said supervision computer (CS) of an emergency procedure in said vehicle (V). Supervision computer (CS) suitable for supervising the performance of actions in a vehicle (V) comprising a main battery (BP) associated with a battery computer (CB), and suitable for communicating with the latter (CB), characterized in which it comprises a monitoring device (DS) according to claim 6. Vehicle (V) comprising a main battery (BP) associated with a battery computer (CB), characterized in that it further comprises a supervision computer (CS), capable of supervising the performance of actions in said vehicle ( V) and to communicate with said main battery (BP), and a monitoring device (DS) according to claim 6, or a supervision computer (CS) according to claim 7. Vehicle according to claim 8, characterized in that it is of the automobile type.