FR3131092A1 - METHOD FOR MONITORING THE OPERATION OF TEMPERATURE SENSORS OF BATTERY MODULES - Google Patents

Abstract

One aspect of the invention relates to a method (100) for monitoring the operation of temperature sensors of modules of a traction battery of a vehicle, the modules each comprising a plurality of cells and a plurality of temperature sensors. The method (100) comprises, for each module, the steps, executed by vehicle control means, of: receiving (101) cell temperature values measured by said temperature sensors, determining (102) temperature differences temperature values received relative to a reference temperature, if at least one of the determined temperature deviations is greater than a predetermined threshold, alerting (103) a driver of a malfunction of at least one of said temperature sensors. Figure 3

Description

METHOD FOR MONITORING THE OPERATION OF TEMPERATURE SENSORS OF BATTERY MODULES

One aspect of the invention relates to a method for monitoring the operation of module temperature sensors of a traction battery. The invention lies in the field of thermal monitoring of the modules of a traction battery, in particular of a vehicle traction battery.

Electric or rechargeable hybrid vehicles are equipped with a traction battery. Such a traction battery is adapted to supply electric power to an electric traction machine of the vehicle and is adapted to be recharged by receiving electric power through a converter, a charging station or even a an electric traction machine during regenerative braking.

The temperature of such a traction battery usually increases as a function of the solicitation of the latter in charging or discharging. When the stress is too great, thermal runaway of one of the modules in the battery can occur. Such thermal runaway then propagates to other adjacent modules.

For example, document FR-B1-3093028 discloses a method for managing an air conditioning circuit connected to a cooling circuit of a battery. According to this method, when the temperature of a traction battery exceeds a temperature threshold, a cooling circuit returns to its full operating potential to cool the traction battery of the vehicle as much as possible, down to a temperature threshold below from which the cooling circuit resumes normal operation.

It should be noted, however, that the temperature measurement may be erroneous. Thus, the value of the measured temperature of a traction battery may be suitable while the battery may actually be at too high an operating temperature. In such a situation, the cooling circuit retains its normal operation and does not effectively cool the battery which is overheated. This overheated battery is therefore not sufficiently cooled and risks catching fire.

Conversely, it is possible that the measured temperature value of the traction battery is too high when the actual operating temperature is suitable. In such a situation, the driver of the vehicle may be unnecessarily warned to leave his vehicle urgently.

The object of the invention is to overcome the drawbacks of the prior art by proposing a method for monitoring the operation of temperature sensors of modules of a traction battery making it possible to eliminate any risk of false temperature measurement.

In this context, the invention thus relates, in its broadest sense, to a method for monitoring the operation of temperature sensors of modules of a traction battery of a vehicle, the modules each comprising a plurality of cells and a plurality of temperature sensors.

• recevoir des valeurs de température des cellules mesurées par les capteurs de température,
• déterminer des écarts de température des valeurs de température reçues par rapport à une température de référence,
• si au moins un des écarts de température déterminé est supérieur à un seuil prédéterminé, alerter un conducteur d’un dysfonctionnement d’au moins un des capteurs de température.

The method according to this aspect of the invention comprises, for each module, the steps, executed by vehicle control means, of:

• receive cell temperature values measured by the temperature sensors,
• determining temperature deviations of the temperature values received with respect to a reference temperature,
• if at least one of the determined temperature differences is greater than a predetermined threshold, alerting a driver of a malfunction of at least one of the temperature sensors.

This process thus makes it possible to guarantee the temperature information from the temperature sensors of the same module of the traction battery. Thus, this process makes it possible to mitigate any risk of thermal degradation of the modules of the traction battery and makes it possible to avoid any risk of thermal runaway of the traction battery which would be due to a false measurement. The safety of vehicle passengers against a risk of fire in the traction battery is thus improved.

In addition, the method according to this aspect of the invention makes it possible to avoid false detection of a thermal runaway of the traction battery and therefore to evacuate the passengers from the vehicle unnecessarily.

In addition to the characteristics which have just been mentioned in the previous paragraph, the method according to the invention may have one or more additional characteristics among the following, considered individually or in all technically possible combinations.

According to a non-limiting aspect of the invention, the temperature differences are determined as a percentage.

According to a non-limiting aspect of the invention, the reference temperature is selected from the temperature values received and corresponds to a maximum temperature or a minimum temperature.

According to a non-limiting aspect of the invention, the steps of receiving temperature values and determining temperature differences are repeated periodically, if at least one of the temperature differences determined within the module is greater than the predetermined threshold during a first period of predetermined time, the step of alerting comprises a sub-step of displaying a warning light on a console of the vehicle.

According to a non-limiting aspect of the invention, the method comprises a step of turning off the light when all the determined temperature differences of the module are, for a second predetermined period of time, below the predetermined threshold.

• afficher un voyant sur une console du véhicule, et
• limiter une charge et une décharge de la batterie de traction.

According to a non-limiting aspect of the invention, the steps of receiving temperature values and determining temperature differences are repeated periodically, if at least two of the temperature differences determined within the module are greater than the predetermined threshold during a third period predetermined time, the step of alerting comprises the sub-steps of:

• display a warning light on a console of the vehicle, and
• limit charging and discharging of the traction battery.

According to a non-limiting aspect of the invention, the method comprises a step of stopping the limitation of charging and discharging of the traction battery when, during a sixth predetermined period of time, at most a determined temperature difference is greater than the predetermined threshold .

• afficher un voyant d’arrêt sur une console du véhicule ;
• interdire une charge et une décharge de la batterie de traction.

According to a non-limiting aspect of the invention, the steps of receiving temperature values and determining temperature differences are repeated periodically, if at least three of the temperature differences determined within the module are greater than the predetermined threshold during a seventh period predetermined time, the step of alerting comprises the sub-steps of:

• displaying a stop light on a console of the vehicle;
• prohibit charging and discharging of the traction battery.

• piloter une isolation électrique de la batterie de traction vis-à-vis d’un réseau haute tension du véhicule ;
• opérer une décharge active du réseau haute tension du véhicule.

According to a non-limiting aspect of the invention, the method comprises the steps of:

• control electrical isolation of the traction battery vis-à-vis a high voltage network of the vehicle;
• actively discharge the vehicle's high-voltage network.

• éteindre le voyant d’arrêt du véhicule ;
• stopper l’interdiction de charge et de décharge de la batterie de traction.

According to a non-limiting aspect of the invention, when, during a tenth predetermined period of time, at most two determined temperature differences are greater than the predetermined threshold, the method comprises the steps of:

• turn off the vehicle's stop light;
• stop the ban on charging and discharging the traction battery.

The invention and its various applications will be better understood on reading the following description and examining the accompanying figures.

schematically illustrates a traction battery.

schematically illustrates a vehicle equipped in particular with the traction battery which is illustrated in .

schematically represents a diagram of steps of a non-limiting mode of implementation of the method according to the invention.

There schematically illustrates a traction battery of a vehicle.

The traction battery 1 comprises, in this non-limiting embodiment, eighteen modules 2 (only four modules 2 are illustrated). Each module 2 comprises twelve cells 3 and six temperature sensors 4. Each temperature sensor 4 is connected to two modules 2 so as to measure the temperature of the two modules 2.

• une batterie de traction 1 similaire à celle illustrée à la ,
• une machine électrique de traction 6 permettant, d’une part, de recharger la batterie de traction 1 lors d’un freinage récupératif et, d’autre part, d’entraîner en rotation les roues du véhicule 5,
• un convertisseur 7, ce convertisseur 7 est, par exemple, un convertisseur continu-continu utilisé pour la conversion de la tension entre une batterie haute tension comme la batterie de traction 1, et une batterie basse tension comme une batterie de servitude (non représentée), et intègre en outre un chargeur embarqué, couramment désigné par l'homme du métier sous l'acronyme OBC pour « On Board Charger » en anglais, utilisé pour la recharge de la batterie de traction 1 ; et
• des moyens de contrôle 8 agencés pour mettre en œuvre un procédé de surveillance de fonctionnement de capteurs de température de modules d’une batterie de traction d’un véhicule selon un aspect de l’invention.

There illustrates a vehicle 5 arranged to implement the method according to the invention. Vehicle 5 comprises in particular:

• a traction battery 1 similar to that illustrated in ,
• an electric traction machine 6 making it possible, on the one hand, to recharge the traction battery 1 during regenerative braking and, on the other hand, to drive the wheels of the vehicle 5 in rotation,
• a converter 7, this converter 7 is, for example, a direct-direct converter used for converting the voltage between a high voltage battery such as traction battery 1, and a low voltage battery such as a service battery (not shown) , and further incorporates an on-board charger, commonly referred to by those skilled in the art by the acronym OBC for “On Board Charger” in English, used for recharging the traction battery 1; And
• control means 8 arranged to implement a method for monitoring the operation of module temperature sensors of a traction battery of a vehicle according to one aspect of the invention.

The control means 8 can for example comprise a vehicle control unit 9 (better known by the acronym VCU for Vehicle Control Unit in English) and a battery control system 10 (better known by the acronym BMS for Battery Management System in English).

There shows a diagram of steps of an embodiment of the method 100 according to the invention. The steps of the method 100 are executed by control means such as, for example, the control means 8 shown in .

The method 100 of monitoring the operation of temperature sensors 4 of modules 2 of a traction battery 1 of a vehicle 5 comprises, for each module 2, a step executed for example by means of the battery control system 10 of receiving 101 of the temperature values of the cells 3 measured by the temperature sensors 4. Thus, each temperature sensor 4 transmits a value of a temperature representative of the temperature of the two cells 3 to which it is connected.

The method 100 further comprises a step, executed for example by means of the battery monitoring system 10, of determining 102 temperature deviations of the temperature values received with respect to a reference temperature.

In a mode of non-limiting implementation, the temperature differences are determined as a percentage. Furthermore, the reference temperature can be selected from among the temperature values received and corresponds to a maximum temperature or a minimum temperature of these temperature values received.

For example, when the reference temperature is a maximum temperature, the battery control system 10 selects the maximum temperature of the six temperature values received, the six temperature values having been transmitted by the six temperature sensors 4 of a module n . Thus, the maximum temperature of a module n, Tmaxn = max (Tn1; Tn2; Tn3; Tn4; Tn5; Tn6).

• Tn1= température mesurée par un premier capteur de température 4 du module n ;
• Tn2= température mesurée par un deuxième capteur de température 4 du module n ;
• Tn3= température mesurée par un troisième capteur de température 4 du module n ;
• Tn4= température mesurée par un quatrième capteur de température 4 du module n ;
• Tn5= température mesurée par un cinquième capteur de température 4 du module n ;
• Tn6= température mesurée par un sixième capteur de température 4 du module n ;

With :

• Tn1=temperature measured by a first temperature sensor 4 of module n;
• Tn2=temperature measured by a second temperature sensor 4 of module n;
• Tn3=temperature measured by a third temperature sensor 4 of module n;
• Tn4=temperature measured by a fourth temperature sensor 4 of module n;
• Tn5=temperature measured by a fifth temperature sensor 4 of module n;
• Tn6=temperature measured by a sixth temperature sensor 4 of module n;

The percentage deviations between each of these temperatures Tn1, Tn2, Tn3, Tn4, Tn5 and T6 and the selected maximum temperature of module n are then determined.

• un premier écart E1% de température en pourcentage du module n = (Tmaxn – Tn1) * 100/Tn1 ;
• un deuxième écart E2% de température en pourcentage du module n = (Tmaxn – Tn2) * 100/Tn2 ;
• un troisième écart E3% de température en pourcentage du module n = (Tmaxn – Tn3) * 100/Tn3 ;
• un quatrième écart E4% de température en pourcentage du module n = (Tmaxn – Tn4) * 100/Tn4 ;
• un cinquième écart E5% de température en pourcentage du module n = (Tmaxn – Tn5) * 100/Tn5 ;
• un sixième écart E6% de température en pourcentage du module n = (Tmaxn – Tn6) * 100/Tn6.

Thus, the battery control system 10 determines:

• a first temperature difference E1% as a percentage of the module n = (Tmaxn – Tn1) * 100/Tn1;
• a second temperature difference E2% as a percentage of the module n = (Tmaxn – Tn2) * 100/Tn2;
• a third temperature difference E3% as a percentage of the module n = (Tmaxn – Tn3) * 100/Tn3;
• a fourth temperature difference E4% as a percentage of the module n = (Tmaxn – Tn4) * 100/Tn4;
• a fifth temperature difference E5% as a percentage of the module n = (Tmaxn – Tn5) * 100/Tn5;
• a sixth deviation E6% of temperature in percentage of the module n = (Tmaxn – Tn6) * 100/Tn6.

In a different implementation, when the reference temperature is a minimum temperature, the battery control system 10 selects the minimum temperature from among the six temperature values received. Thus, the minimum temperature of a module n, Tminn = min (Tn1; Tn2; Tn3; Tn4; Tn5; Tn6).,

• Tn1= température mesurée par un premier capteur de température 4 du module n ;
• Tn2= température mesurée par un deuxième capteur de température 4 du module n ;
• Tn3= température mesurée par un troisième capteur de température 4 du module n ;
• Tn4= température mesurée par un quatrième capteur de température 4 du module n ;
• Tn5= température mesurée par un cinquième capteur de température 4 du module n ;
• Tn6= température mesurée par un sixième capteur de température 4 du module n ;

With :

• Tn1=temperature measured by a first temperature sensor 4 of module n;
• Tn2=temperature measured by a second temperature sensor 4 of module n;
• Tn3=temperature measured by a third temperature sensor 4 of module n;
• Tn4=temperature measured by a fourth temperature sensor 4 of module n;
• Tn5=temperature measured by a fifth temperature sensor 4 of module n;
• Tn6=temperature measured by a sixth temperature sensor 4 of module n;

The percentage deviations between each of these temperatures Tn1, Tn2, Tn3, Tn4, Tn5 and T6 and the selected minimum temperature of module n are then determined.

• un premier écart E1% de température en pourcentage du module n = (Tn1 - Tminn) * 100/ Tminn ;
• un deuxième écart E2% de température en pourcentage du module n = (Tn2 - Tminn) * 100/Tminn ;
• un troisième écart E3% de température en pourcentage du module n = (Tn3 - Tminn) * 100/Tminn ;
• un quatrième écart E4% de température en pourcentage du module n = (Tn4 - Tminn) * 100/Tminn ;
• un cinquième écart E5% de température en pourcentage du module n = (Tn5 - Tminn) * 100/Tminn ;
• un sixième écart E6% de température en pourcentage du module n = (Tn6 - Tminn) * 100/Tminn.

Thus, the battery control system 10 determines:

• a first difference E1% of temperature as a percentage of the module n = (Tn1 - Tminn) * 100/Tminn;
• a second temperature difference E2% as a percentage of the modulus n = (Tn2 - Tminn) * 100/Tminn;
• a third temperature difference E3% as a percentage of the modulus n = (Tn3 - Tminn) * 100/Tminn;
• a fourth temperature difference E4% as a percentage of the modulus n=(Tn4-Tminn)*100/Tminn;
• a fifth temperature deviation E5% as a percentage of the modulus n = (Tn5 - Tminn) * 100/Tminn;
• a sixth deviation E6% of temperature as a percentage of the modulus n = (Tn6 - Tminn) * 100/Tminn.

When at least one of the temperature differences E1%, E2%, E3%, E4%, E5%, and E6% determined is greater than a predetermined threshold, the method 100 includes a step of alerting 103 a driver of the vehicle 5 a malfunction of at least one of the temperature sensors 4.

Thus, each percentage of temperature difference E1%, E2%, E3%, E4%, E5%, and E6% of the six temperature information of the same module n is compared to the predetermined threshold. By way of non-limiting example, the predetermined threshold can be between 5% and 15%, typically 10%. In other words, the battery control system 10 sets up an alert when a temperature difference E1%, E2%, E3%, E4%, E5%, or E6% is greater than 10% in the same module. It is understood that the aforementioned steps are carried out for each of the modules 2 of the traction battery 1.

It should be noted that the steps of receiving 101 temperature values and determining 102 temperature differences are repeated periodically. Thus, the determination of the temperature differences E1%, E2%, E3%, E4%, E5%, and E6% of the temperature values Tn1, Tn2, Tn3, Tn4, Tn5 and Tn6 received with respect to a reference temperature is carried out periodically according to a predetermined reiteration period between the moment when the driver switched on the ignition and the moment when the driver switched off the ignition of the vehicle 5. This predetermined reiteration period can for example be between 500 and 1500 milliseconds, typically 1000 milliseconds. In other words, the battery control system 10 determines the temperature differences of the six sensors of the same module n every 1000 milliseconds.

In a first malfunction situation, when one of the temperature differences E1%, E2%, E3%, E4%, E5% or E6% determined within module n is greater than the predetermined threshold of 10% during a first period of predetermined time, the step of alerting 103 includes a sub-step of displaying 104 an indicator light on a console of the vehicle 5. This first predetermined period of time can for example be between 2000 and 4000 milliseconds, typically 3000 milliseconds.

The indicator shows that one of the temperature differences E1%, E2%, E3%, E4%, E5% or E6% determined is too great and that consequently one of the temperature sensors 4 of module n is faulty The indicator may be a service light prompting the driver to carry out a diagnosis at the garage. In a non-limiting exemplary embodiment, the sub-step of displaying 104 an indicator light on a console of the vehicle 5, consists, for the battery control system 10, in transmitting a request to the vehicle control unit 9 to drive a warning light display to alert the driver. The vehicle control unit 9 then drives a display of the warning light to alert the driver.

In a non-limiting exemplary embodiment, the method 100 comprises a step of recording 105 a first malfunction code. This first malfunction code 105 reflects that one of the determined E1%, E2%, E3%, E4%, E5% or E6% temperature deviations is too large and therefore one of the 4 temperature sensors has failed. To this end, the battery control system 10 can record the first malfunction code in its ROM to indicate to the after-sales service the source of the malfunction.

The method 100 further comprises a step, executed for example by means of the battery monitoring system 10, of turning off 106 the light when all the temperature differences E1%, E2%, E3%, E4%, E5% and E6% determined modulus n are, for a second predetermined period of time, below the predetermined threshold of 10% in the example described. This second predetermined period of time can for example be between 500 and 1500 milliseconds, typically 1000 milliseconds.

• afficher 107 un voyant sur la console du véhicule 5, et
• limiter 108 une charge et une décharge de la batterie de traction 1.

In a second malfunction situation, when two of the temperature differences E1%, E2%, E3%, E4%, E5%, E6% determined within module n are greater than the predetermined threshold of 10% for a third period of time predetermined, the step of alerting 103 comprises the sub-steps of:

• display 107 a warning light on the vehicle console 5, and
• limit 108 charging and discharging of traction battery 1.

This third predetermined period of time can for example be between 2000 and 4000 milliseconds, typically 3000 milliseconds.

The light reflects that two determined temperature differences are too great and that consequently two temperature sensors 4 are faulty. The light may be a service light indicating to the driver that a performance limitation is in place and prompting the driver to carry out a diagnosis at the garage.

In a non-limiting exemplary embodiment, the substep of displaying 107 an indicator light on a console of the vehicle 5, consists, for the battery control system 10, in transmitting a request to the vehicle control unit 9 to drive a warning light display to alert the driver.

• lorsque le véhicule 5 est en mode roulage, limiter la puissance électrique fournie par la batterie de traction 1 à la machine électrique de traction 6 du véhicule 5 à une puissance machine prédéterminée, par exemple comprise entre 8 et 9kW, typiquement 8,5kW; la limitation étant réalisée sur une quatrième période de temps prédéterminée, par exemple comprise entre 50 et 70 secondes, typiquement 60 secondes ;
• lorsque le véhicule 5 est en mode freinage récupératif, limiter la puissance électrique fournie à la batterie de traction 1 lors d’un freinage récupératif à une puissance batterie prédéterminée, par exemple comprise entre 8 et 9kW, typiquement 8,5kW ; la limitation étant réalisée sur une cinquième période de temps prédéterminée, par exemple comprise entre 50 et 70 secondes, typiquement 60 secondes ;
• lorsque le véhicule 5 est en mode recharge, limiter un courant de charge de la batterie de traction 1 à un courant de charge prédéterminé, ce courant de charge prédéterminé peut par exemple être compris entre 40 et 60%, typiquement 50%, du courant de charge autorisé lorsqu’aucun dysfonctionnement n’est détecté.

In a non-limiting exemplary embodiment, the step of limiting 108 the charging and discharging of the traction battery 1, executed for example by means of the battery control system 10, consists of:

• when the vehicle 5 is in driving mode, limiting the electric power supplied by the traction battery 1 to the electric traction machine 6 of the vehicle 5 to a predetermined machine power, for example between 8 and 9 kW, typically 8.5 kW; the limitation being carried out over a fourth predetermined period of time, for example between 50 and 70 seconds, typically 60 seconds;
• when the vehicle 5 is in regenerative braking mode, limiting the electrical power supplied to the traction battery 1 during regenerative braking to a predetermined battery power, for example between 8 and 9 kW, typically 8.5 kW; the limitation being carried out over a fifth predetermined period of time, for example between 50 and 70 seconds, typically 60 seconds;
• when the vehicle 5 is in charging mode, limiting a charging current of the traction battery 1 to a predetermined charging current, this predetermined charging current can for example be between 40 and 60%, typically 50%, of the current of charge allowed when no malfunction is detected.

In a non-limiting exemplary embodiment, the limitation of the electric power supplied by the traction battery 1 to the electric traction machine 6 of the vehicle 5 to a predetermined machine power and the limitation of the electric power supplied to the traction battery 1 during regenerative braking at a predetermined battery power are performed linearly.

In a non-limiting exemplary embodiment, the method 100 comprises a step of recording 109 a second malfunction code. This second malfunction code reflects that two determined temperature deviations are too large and therefore two temperature sensors 4 of module n have failed. To this end, the battery monitoring system 10 can save the second malfunction code in its ROM to indicate to the after-sales service the source of the malfunction.

The method 100 comprises a step, executed for example by means of the battery control system 10, of stopping 110 the charging and discharging limitation of the traction battery 1 when, during a sixth predetermined period of time, at most a difference of determined temperature is higher than the predetermined threshold. This sixth predetermined period of time can for example be between 500 and 1500 milliseconds, typically 1000 milliseconds.

• stopper la limitation de puissance électrique fournie par la batterie de traction 1 à la machine électrique de traction 6 du véhicule 5 à une puissance machine prédéterminée ;
• stopper la limitation de puissance électrique fournie à la batterie de traction 1 lors d’un freinage récupératif à une puissance batterie prédéterminée ; ou
• stopper la limitation du courant de charge de la batterie de traction 1 à un courant de charge prédéterminé.

In a non-limiting exemplary embodiment, the step of stopping 110 the charging and discharging limitation of the traction battery 1 consists of:

• stopping the limitation of electric power supplied by traction battery 1 to electric traction machine 6 of vehicle 5 at a predetermined machine power;
• stop the limitation of electrical power supplied to traction battery 1 during regenerative braking at a predetermined battery power; Or
• stop the limitation of the charging current of traction battery 1 to a predetermined charging current.

• Afficher 111 un voyant d’arrêt sur la console du véhicule 5, et
• interdire 112 la charge et la décharge de la batterie de traction 1.

In a third malfunction situation, when three of the temperature differences E1%, E2%, E3%, E4%, E5%, E6% determined within module n are greater than the predetermined threshold of 10% for a seventh period of time predetermined, the step of alerting 103 comprises the sub-steps of:

• display 111 a stop light on the console of vehicle 5, and
• prohibit 112 the charging and discharging of the traction battery 1.

This seventh predetermined period of time can for example be between 2000 and 4000 milliseconds, typically 3000 milliseconds.

In a non-limiting exemplary embodiment, the sub-step of displaying 111 a stop light on a console of the vehicle 5, consists, for the battery control system 10, in transmitting a request to the vehicle control unit 9 drive a stop light display to alert the driver. The stop light reflects that three determined temperature differences are too great and that consequently three of the six temperature sensors 4 of a module n are faulty. The stop light may be a stop light.

• lorsque le véhicule 5 est en mode roulage, interdire la puissance électrique fournie par la batterie de traction 1 à la machine électrique de traction 6, l’interdiction étant réalisée sur une huitième période de temps prédéterminée, par exemple comprise entre 50 et 70 secondes, typiquement 60 secondes dans notre exemple ;
• lorsque le véhicule 5 est en mode freinage récupératif, interdire la puissance électrique fournie à la batterie de traction 1 lors d’un freinage récupératif, l’interdiction étant réalisée sur une neuvième période de temps prédéterminée, par exemple comprise entre 50 et 70 secondes, typiquement 60 secondes dans notre exemple ; et
• lorsque le véhicule 5 est en mode recharge, interdire le courant de charge de la batterie de traction 1.

In a non-limiting exemplary embodiment, the step of prohibiting 112 the charging and discharging of the traction battery 1 is executed by means of the battery control system 10 and consists of:

• when the vehicle 5 is in driving mode, prohibit the electric power supplied by the traction battery 1 to the electric traction machine 6, the prohibition being carried out over an eighth predetermined period of time, for example between 50 and 70 seconds, typically 60 seconds in our example;
• when the vehicle 5 is in regenerative braking mode, prohibiting the electrical power supplied to the traction battery 1 during regenerative braking, the prohibition being carried out over a ninth predetermined period of time, for example between 50 and 70 seconds, typically 60 seconds in our example; And
• when the vehicle 5 is in charging mode, prohibit the charging current of the traction battery 1.

In a non-limiting exemplary embodiment, the prohibition of the electric power supplied by the traction battery 1 to the electric traction machine 6 of the vehicle 5 and the prohibition of the electric power supplied to the traction battery 1 during regenerative braking are performed in a linear fashion.

In a non-limiting exemplary embodiment, the method 100 comprises a step of recording 113 a third malfunction code. This third malfunction code reflects that three of the six temperature deviations determined are too large and therefore three of the six temperature sensors 4 of the same module have failed. To this end, the battery control system 10 can store the third malfunction code in its ROM to indicate to the after-sales service the source of the malfunction.

• Piloter 114, via le système de contrôle batterie 10, une isolation électrique de la batterie de traction 1 vis-à-vis d’un réseau haute tension du véhicule 5, cette isolation électrique pouvant être réalisée, par exemple, en ouvrant des contacteurs d’isolation qui lient la batterie de traction 1 au réseau haute tension (non illustré) du véhicule 5 ;
• Opérer 115, via l’unité de contrôle véhicule 9, une décharge active du réseau haute tension du véhicule 5. Cette étape d’opérer115 une décharge active du réseau haute tension peut être effectuée à l’issue d’une durée prédéterminée, par exemple comprise entre 30 et 90 secondes, typiquement 60 secondes, décomptée à partir du déclenchement de l’étape de piloter 114 une isolation électrique de la batterie de traction 1.

The method 100 further includes the steps of

• Control 114, via the battery control system 10, an electrical isolation of the traction battery 1 vis-à-vis a high voltage network of the vehicle 5, this electrical isolation being able to be achieved, for example, by opening contactors of insulation which link the traction battery 1 to the high voltage network (not shown) of the vehicle 5;
• Operate 115, via the vehicle control unit 9, an active discharge of the high voltage network of the vehicle 5. This step of operating 115 an active discharge of the high voltage network can be carried out at the end of a predetermined duration, for example between 30 and 90 seconds, typically 60 seconds, counted from the triggering of the step of controlling 114 electrical insulation of traction battery 1.

• un premier contacteur relié à une sortie positive de la batterie de traction 1 et une entrée positive de la machine électrique de traction 6, du convertisseur 7 ainsi qu’à une station de recharge (non illustrée) ;
• un deuxième contacteur relié à une sortie négative de la batterie de traction 1 et à une entrée négative de la machine électrique de traction 6, du convertisseur 7 ainsi qu’à la station de recharge.

As a non-limiting example, these isolation contactors can be formed by:

• a first contactor connected to a positive output of the traction battery 1 and a positive input of the electric traction machine 6, of the converter 7 as well as to a charging station (not shown);
• a second contactor connected to a negative output of the traction battery 1 and to a negative input of the electric traction machine 6, of the converter 7 as well as to the charging station.

• quand ils sont fermés, le courant circule de la batterie de traction 1 vers les organes électriques du véhicule 5, autrement dit le courant peut circuler dans le réseau haute tension du véhicule 5 ;
• quand ils sont ouverts, la batterie de traction 1 est isolée électriquement du réseau haute tension du véhicule 5.

These contactors are circuit breaker type contactors:

• when they are closed, the current flows from the traction battery 1 to the electric components of the vehicle 5, in other words the current can flow in the high voltage network of the vehicle 5;
• when they are open, the traction battery 1 is electrically isolated from the high voltage network of the vehicle 5.

Thus, by controlling the opening of these contactors, the traction battery 1 is electrically isolated and is no longer electrically stressed.

By active discharge of the high voltage network is meant the fact of eliminating the voltage residual present in the high voltage network. To this end, this voltage residual can be transformed into heat in the electric traction machine 6 as well as in the converter 7. The residual voltage of the high voltage network is thus reduced from 400V to less than 60V. This residual voltage is thus eliminated between the insulation contactors and the electric traction machine 6, the insulation contactors and the converter 7 as well as between the insulation contactors and the charging station.

• éteindre 116 le voyant d’arrêt du véhicule 5;
• stopper 117 l’interdiction de charge et de décharge de la batterie de traction 1.

When, during a tenth predetermined period of time, at most two determined temperature differences are greater than the predetermined threshold, the method 100 further comprises the steps executed for example by means of the battery monitoring system 10 of:

• turning off 116 the vehicle stop light 5;
• stop 117 prohibition of charging and discharging traction battery 1.

This tenth predetermined period of time can for example be between 500 and 1500 milliseconds, typically 1000 milliseconds.

• lorsque le véhicule 5 est en mode roulage, stopper l’interdiction de puissance électrique fournie par la batterie de traction 1 à la machine électrique de traction 6,
• lorsque le véhicule 5 est en mode freinage récupératif, stopper l’interdiction de puissance électrique fournie à la batterie de traction 1 lors d’un freinage récupératif; ou
• lorsque le véhicule 5 est en mode recharge, stopper l’interdiction du courant de charge de la batterie de traction 1.

In a non-limiting implementation, the step of stopping 117 the prohibition of charging and discharging of the traction battery 1 consists of:

• when the vehicle 5 is in driving mode, stopping the prohibition of electric power supplied by the traction battery 1 to the electric traction machine 6,
• when the vehicle 5 is in regenerative braking mode, stopping the prohibition of electrical power supplied to the traction battery 1 during regenerative braking; Or
• when the vehicle 5 is in charging mode, stopping the prohibition of the charging current of the traction battery 1.

• S’assurer du bon fonctionnement des capteurs de température 4 agencés pour mesurer la température des cellules 3 d’une batterie de traction 1 ;
• Améliorer la sécurité des passagers du véhicule 5 vis-à-vis du risque d’incendie de la batterie de traction.

The various aspects of the invention mentioned above have numerous advantages. Among these, we can cite:

• Ensure the correct operation of the temperature sensors 4 arranged to measure the temperature of the cells 3 of a traction battery 1;
• Improve the safety of the passengers of the vehicle 5 vis-à-vis the risk of fire of the traction battery.

It should be noted that the person skilled in the art is able to provide different variants to the aforementioned aspects of the invention, for example by modifying the value of the different temperature thresholds as well as the different time periods.

Claims (10)

Method (100) for monitoring the operation of temperature sensors of modules (2) of a traction battery (1) of a vehicle (5), said modules (2) each comprising a plurality of cells (3) and a plurality of temperature sensors (4), said method (100) being characterized in that it comprises, for each module (2), the steps, executed by control means (8) of said vehicle (5), of:

• receiving (101) temperature values of said cells (3) measured by said temperature sensors (4),
• determining (102) temperature deviations of said received temperature values with respect to a reference temperature,
• if at least one of said determined temperature differences is greater than a predetermined threshold, alerting a driver of a malfunction of at least one of said temperature sensors (4).

Method (100) according to the preceding claim, characterized in that the temperature differences are determined as a percentage. Method (100) according to any one of the preceding claims, characterized in that the reference temperature is selected from the temperature values received and corresponds to a maximum temperature or a minimum temperature. Method (100) according to any one of the preceding claims, characterized in that the steps of receiving (101) temperature values and determining (102) temperature differences are repeated periodically, if at least one of the determined temperature differences within the module (2) is greater than the predetermined threshold for a first predetermined period of time, the step of alerting (103) includes a sub-step of displaying (104) an indicator on a console of the vehicle (5). Method (100) according to the preceding claim, characterized in that it comprises a step of turning off (106) the light when all the determined temperature differences of the module (2) are, during a second predetermined period of time, below the threshold predetermined. Method (100) according to any one of Claims 1 to 3, characterized in that the steps of receiving (101) temperature values and determining (102) temperature differences are repeated periodically, if at least two of the temperature differences temperature determined within the module (2) are above the predetermined threshold for a third predetermined period of time, the step of alerting (103) comprises the sub-steps of:

• display (107) an indicator on a console of the vehicle (5), and
• limiting (108) charging and discharging of the traction battery (1).

Method (100) according to the preceding claim, characterized in that it comprises a step of stopping (110) the charging and discharging limitation of the traction battery (1) when, during a sixth predetermined period of time, at most one determined temperature difference is greater than the predetermined threshold. Method (100) according to any one of Claims 1 to 3, characterized in that the steps of receiving (101) temperature values and determining (102) temperature differences are repeated periodically, if at least three of the temperature differences temperature determined within the module (2) are above the predetermined threshold for a seventh predetermined period of time, the step of alerting (103) comprises the sub-steps of:

• display (111) a stop light on a vehicle console (5),
• prohibit (112) charging and discharging of the traction battery (1).

Method (100) according to the preceding claim, characterized in that it comprises the steps of:

• control (114) electrical insulation of the traction battery (1) vis-à-vis a high voltage network of the vehicle (5),
• operate (115) an active discharge of said high voltage network of the vehicle (5).

Method (100) according to the preceding claim, characterized in that when, during a tenth predetermined period of time, at most two determined temperature differences are greater than the predetermined threshold, said method (100) comprises the steps of:

• turn off (116) the vehicle stop light (5),
• stop (117) the prohibition of charging and discharging of the traction battery (1).