FR3122362A1 - ASSEMBLY AND METHOD FOR MANAGING AN ELECTRICAL NETWORK OF A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to an electric assembly (500) of a motor vehicle, the electric assembly (500) comprising:- an electric battery (1), - an electric energy generator (2) electrically connected to the electric battery (1) ,- a plurality of sensors (4) electrically connected to the electric battery (1) and to the electric power generator (2),- a plurality of electric devices (3, 30, 31) connected to the electric battery (1) and to the electrical energy generator (2), characterized in that the electrical assembly (500) further comprises two securing devices (5) configured to, in the event of detection of a short-circuit on the electrical assembly (500), being able to take an activated configuration in which the electrical assembly (500) is separated into: - a first electrical network (501), comprising at least one electrical device connected to the DCDC voltage converter and - a second electrical network ( 502) in which at least one electrical safety device ire (31) of the electrical assembly (500) is exclusively electrically connected to at least one electric battery (1). Fig. 1

Description

ASSEMBLY AND METHOD FOR MANAGING AN ELECTRICAL NETWORK OF A MOTOR VEHICLE

The technical context of the present invention is that of the management and control of an electrical network of a motor vehicle. The present invention finds a particularly advantageous application in electric vehicles.

On an electric vehicle, the system for supplying very low voltage electrical energy (typically 12 Volt) comprises schematically in particular an electric battery configured to deliver a direct current at a voltage of 12 Volt (for example a 12 Volt storage device), a converter DCDC voltage supply, connected to a high-voltage energy source, which acts as an electrical energy generator to recharge the 12 Volt electric battery, and also the 12 Volt on-board network, which includes all the electrical consumers powered by the electric heater and/or by the DCDC voltage converter.

In such an on-board network, the uninterrupted supply of electrical energy to electrical consumers intended for the safety needs of the vehicle such as, by way of non-limiting examples, braking, trajectory correction and/or power steering, takes on a particular importance.

The on-board network is conventionally connected to the electric battery and to the DCDC voltage converter so as to be able to be powered by these two elements. In the same way, the DCDC voltage converter is itself connected to the 12 Volt electric battery so that it can be recharged.

When a short-circuit appears on such an on-board network, the risk is of no longer being able to supply the entire network and therefore, in particular, all of the safe electrical consumers, this not ensuring the level of security maximum possible. This can also be a brake on the sale of electric vehicles in certain markets.

The object of the present invention is to propose a new solution making it possible to guarantee the supply, in particular, of the safe electrical consumers of such a vehicle in all circumstances and, in particular, when a short-circuit occurs in the on-board network.

For this purpose, according to a first aspect, the subject of the invention is an electrical assembly for a motor vehicle, the electrical assembly comprising:

- at least one electric battery,

- an electric power generator electrically connected to at least one electric battery,

- a plurality of sensors electrically connected to the electric battery and to the electric power generator,

- a plurality of electrical devices connected to the at least one electrical battery and to the electrical energy generator, the electrical devices comprising safe electrical devices and standard electrical devices,

characterized in that the electrical assembly further comprises a security device configured to, in the event of detection of a short-circuit on the electrical assembly, being able to adopt an activated configuration in which the electrical assembly is separated into:

- a first electrical network in which a first part of the safe electrical devices are exclusively electrically connected to the electrical energy generator, and

- a second electrical network in which a second part of the safe electrical devices are exclusively electrically connected to the at least one electrical battery.

It should be understood here that the first electrical network and the second electrical network are independent of each other, that is to say that they are electrically isolated from each other. This makes it possible both to guarantee and to secure the power supply of the safety electrical devices.

The condition for switching the safety device to its activated configuration is the detection of a short-circuit in the electrical assembly.

According to an additional characteristic of the electrical assembly according to the invention, the securing device takes the form of at least one electrical switch which:

- when configured in an inactive configuration, the first electrical network and the second electrical network are electrically connected to each other, and

- when configured in its activated configuration, the first electrical network is isolated from the second electrical network.

Advantageously, each electrical switch comprises one or more electronic transistors, in particular of the type of a MOSFET (metal-oxide gate field effect transistor), each electronic transistor opening when the security device is configured in its activated configuration in order to separate the first electrical network from the second electrical network.

Safe electrical devices are those which are activated and/or used during evasive or braking maneuvers of the motor vehicle. In particular, the electrical safety devices include, for example, an electronic motor vehicle trajectory correction device and/or an emergency electrical braking device and/or an electronic power steering device.

Such a securing device therefore makes it possible to carry out, as previously described, the separation of the electrical assembly into two distinct branches which can independently supply one or more electrical devices of the on-board network of the vehicle.

The invention also extends to a motor vehicle equipped with an electrical assembly as just described.

According to a second aspect, the invention extends to a method for securing an electrical assembly as just described, the method being implemented by the securing member, the securing method comprising the following steps :

- a step of monitoring the security device,

- a stage for determining a level of risk linked to the security device.

Advantageously, the monitoring step includes a step of testing the securing device. According to one example, this test step is of the type of a measurement of a capacity of the security device to switch into its activated configuration.

More specifically, according to a characteristic of the method according to the invention, the security device comprising at least one electronic transistor, the step of monitoring the security device comprises:

- a step for measuring a leakage current across the terminals of each at least one electronic transistor,

- a step of qualifying a status of the security device as a function of the measured leakage current, the status accounting for the capacity of the security device to be able to switch into its activated configuration, the status of the device security taking:

- a first value, called faulty, when the security device malfunctions in such a way that it cannot switch to its activated configuration, or

- a second value, called functional, when the security device is able to switch to its activated configuration.

According to various additional characteristics of the method according to the invention, taken separately or in combination:

- the monitoring step includes a step of counting a number of faulty statuses and/or a number of functional statuses, the number of faulty and/or functional statuses being stored so as to be able to be incremented at each occurrence of the monitoring stage. According to one example, the counting step is carried out at each stop of the vehicle.

- in which the monitoring step comprises a step of resetting the number of faulty statuses to a default value, the resetting step being carried out either when, when the motor vehicle is started, the status of the security device is functional, or when, while driving the motor vehicle, the status of the securing member is functional. According to one example, the default value is zero.

- the step of determining the level of risk includes a step of comparing the number of defaulting statuses counted according to a first threshold and a second threshold. More specifically, the method according to the invention provides, on the one hand, that if the number of faulty statuses is between the first threshold and the second threshold, then the level of risk is defined at a first level of risk, and, on the other hand, if the number of faulty statuses is greater than the second threshold, then the risk level is defined at a second risk level. The first level of risk corresponds to a low risk for the safety of the electrical assembly and of the vehicle. The second level of risk corresponds to a high risk for the safety of the electrical assembly and the vehicle. According to one example, the number of faulty statuses defining the first threshold is of the order of a few units, for example 5 faulty statuses, and the number of faulty statuses defining the second threshold is arbitrarily set at twice the number of faulty statuses defining the first threshold, here, for example, 10 failed statuses.

- the step of comparing the number of failed statuses comprises the definition of a third level of risk corresponding to an absence of risk in one of the following two cases: either the level of risk is equal to the first level and the number of failed statuses is reset to its default value, i.e. the risk level is equal to the second level, and the motor vehicle is powered on but not started, and the number of failed statuses is reset to its default value. This third level of risk corresponds to an absence of risk for the electrical assembly and for the motor vehicle.

- the method comprises a step of alerting a user of the motor vehicle according to the determined level of risk, the alert step comprising the piloting of at least one indicator light on a dashboard of the motor vehicle. According to an example, during the alert step, if the level of risk is equal to the first level, then a first light relating to the state of the electric battery is extinguished and a second light relating to a service state of the vehicle car is on. If the risk level is equal to the second level, then the first light is on and the second light is off.

– the alert step includes a step for displaying an alert message on the dashboard of the vehicle. According to an example, if the level of risk is equal to the first level, the alert message is equal to a first message recommending not to start the vehicle, and if the level of risk is equal to the second level, the message of alert is equal to a second message recommending that the vehicle's electrical system be serviced.

the method comprises a step of transferring data generated during the previous steps of the method, such as for example the number of faulty statuses when the risk level is equal to the first level or to the second level.

The invention, by the electrical assembly that it proposes, therefore makes it possible, on the one hand, to achieve a segregation of the electrical supply of a low voltage on-board network of a motor vehicle into two distinct electrically isolated branches from each other, in order to avoid any interruption of such a power supply following, for example, the occurrence of a short-circuit in this on-board network, and, on the other hand, by the process that it proposes to supervise the operation of such a segregation device. In particular, the invention thus makes it possible to guarantee the electrical supply of at least part of the safety devices of the electrical assembly, either by the electric battery or by the electrical energy generator. More particularly, the invention makes it possible to define several levels of risk of a possible malfunction of such a segregation device, to alert the user preventively according to the level of risk identified and to communicate the detection of possible failures to a or several servers that can be used to perform statistical analyzes on the frequency of occurrence of faults or any other type of cross-analysis with other data.

Other characteristics and advantages of the invention will become apparent through the description which follows on the one hand, and the examples of embodiment given by way of indication and not limiting with reference to the appended diagrammatic drawings on the other hand, in which:

schematically illustrates an electrical assembly according to the invention.

schematically illustrates the method according to the invention.

Of course, the characteristics, the variants and the different embodiments of the invention can be associated with each other, according to various combinations, insofar as they are not incompatible or exclusive of each other. In particular, variants of the invention may be imagined comprising only a selection of characteristics described below in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from to the state of the prior art.

In particular, all the variants and all the embodiments described can be combined with each other if nothing prevents this combination from a technical point of view.

In the figures, the elements common to several figures retain the same reference.

With reference to the , an electric assembly 500 of a motor vehicle as provided by the invention comprises in particular an electric battery 1, an electric power generator 2 electrically connected to the electric battery 1 and configured to recharge the latter, one or more electric devices 3 of the motor vehicle electrically connected to the electric battery 1 and to the electric power generator 2, and a plurality 4 of sensors also electrically connected to the electric battery 1 and to the electric power generator 2.

The term electric battery 1 is here to be understood generically, in the sense that such a battery can comprise one or more electric elements configured to fulfill the function of electric battery.

According to various non-exhaustive examples, the electrical energy generator 2 can be of the type of a DCDC voltage converter or of the type of an alternator.

The aforementioned electrical devices 3 typically include standard electrical devices 30 and safety devices 31. By way of non-exhaustive examples, the electrical safety devices 31 can include braking, automatic trajectory correction and/or steering assistance devices. the steering of the vehicle, and the standard electrical devices 30 may include in particular devices for air conditioning, ventilation, heating, lighting, etc.

According to the invention, the electrical assembly 500 also comprises a securing device 5, electrically connected to the electric battery 1, to the electrical energy generator 2, to the electrical devices 3, 30, 31, and to the sensors 4. invention, the security device 5 is configured to assume an activated configuration in which the electrical assembly 500 is separated into, on the one hand, a first network 501 in which a first part 3A of the electrical security devices 31 is exclusively connected to the electric power generator 2, and, on the other hand, a second network 502 in which a second part 3B of the electrical safety devices 31 is exclusively connected to the rechargeable electric battery 1.

The security device 5 advantageously comprises two electrical switches 51, 52 making it possible to achieve this electrical separation. A first electrical switch 51 is electrically connected to the first part 3A of the electrical safety devices 31 and to the electrical energy generator 2 in order to be able to form the first network 501, and a second electrical switch 52 is electrically connected to the second part 3B of the electrical safety devices 31 and to the rechargeable electrical battery 1 in order to be able to form the second network 502.

The invention also provides that the securing device 5 assumes its activated configuration as soon as a short-circuit is observed in the electrical assembly 500.

In the activated configuration, the security device 5 - via the first 51 and the second 52 electrical switch - therefore performs a segregation of the electrical assembly 500 into two distinct subassemblies 501, 502, electrically isolated from one of the other, respectively powered by the electric power generator 2 and by the electric battery 1. The second network 502 comprising part of the electrical security devices 31 as previously described, it follows from the above that, even in the event of a short -circuit in the electrical assembly 500, the uninterrupted operation of these safe electrical devices 31 is guaranteed by their power supply by either the single electric battery 1, or the single DCDC voltage converter. It should be noted that, according to the example more particularly illustrated by the , the sensors 4 previously defined are included in the first network 501 previously described. It goes without saying, however, that if all or part of these sensors is necessary for the correct operation of the aforementioned safety electrical devices 31, the sensors concerned are included in the second network 502 previously described.

The security device 5 - and each electrical switch 51, 52, therefore operates as a switch which, in its activated configuration, performs the aforementioned segregation of the electrical assembly 500 into two separate networks 501, 502, and which, in a inactive configuration, keeps the first network 501 and the second network 502 electrically connected to each other, the elements of the electrical assembly 500 then being electrically connected both to the electric battery 1 and to the electric power generator 2.

According to an advantageous embodiment, the electrical switches 51, 52 forming the security device 5 comprise one or more electronic transistors not shown on the , configured in such a way that they open when the security member 5 is in its activated configuration.

The schematically illustrates the method according to the invention as described previously.

In a first step 100, the method according to the invention monitors the security device 5 as described previously.

More precisely, the first step 100 comprises a first sub-step 101 during which a leakage current 10 is measured at the terminals of the transistor(s) that the security device 5 comprises.

In a second sub-step 102 of the first step 100, a status I1 of the securing device 5 is determined as a function of the value of the aforementioned leakage current I0. The status 11 of the security device 5 can take a first value 110, also designated in the following as a faulty value, representative of the fact that the operation of the security device 5 does not allow switching of the latter in its activated configuration as previously defined. The status of the security device 5 associated with the aforementioned first value 110 will be designated in what follows as the failed status of said security device 5.

The status of the security device 5 can also take a second value 111, representative of the fact that the operation of the security device 5 allows it to switch to its activated configuration. The status of the security device 5 associated with the aforementioned second value 111 will be designated in what follows as the functional status of said security device 5.

The first step 100 of the method according to the invention also comprises a third sub-step 103 during which a number of statuses of the security device 5 is counted. More specifically, during this second sub-step 102, a number 1100 of faulty statuses as previously defined and a number 1111 of functional statuses are counted and recorded, for example, in a memory associated with the security device 5.

According to one example, the third sub-step 103 is carried out each time the vehicle stops.

The first step 100 of the method according to the invention also comprises a fourth sub-step 104 of reinitializing the number 1100 of faulty statuses to a default value, typically chosen at zero. According to one example, the fourth sub-step 104 is carried out when, when the vehicle is started or while driving, the status of the securing device 5 is defined as functional and takes the value 111 previously mentioned. . In other words, as soon as the security device 5 is considered functional once at the end of the second sub-step 102, that is to say capable of taking its activated configuration in which it performs the separation of the electrical assembly 500 as described and illustrated by the into two separate networks 501, 502, as previously described, the method according to the invention provides for a reset of the aforementioned number 1100.

The fourth sub-step 104 is therefore a conditional step, and it is conditioned by the determination of at least one functional status of the security device 5. In other words, as long as a functional status of the security device 5 is not detected, the fourth sub-step 104 is not carried out.

The second step 200 of the method according to the invention comprises a first sub-step 201 during which the number 1100 of faulty statuses of the security device 5 is compared with a first threshold 20 and with a second threshold 21, the second threshold 21 being greater than the first threshold 20. According to one example, the first threshold 20 comprises a few faulty statuses, for example 5, and the second threshold 21 comprises twice as many faulty statuses defining the first threshold 20, for example 10 faulty statuses.

The second step 200 of the method according to the invention also comprises a second sub-step 202, during which a risk level 25 is defined according to the result of the comparison carried out during the first sub-step 201. The second sub-step 202 is therefore carried out consecutively to the first sub-step 201, at the end of the latter. As a reminder, the risk level 25 represents the risk that the security device 5 does not take its activated configuration as previously described and therefore cannot achieve, in the event of a short circuit in the electrical assembly 500, the segregation said electrical assembly into two networks 501, 502, separate and electrically isolated from each other.

More precisely :

- if the number 1100 of failed statuses of the security device 5 is between the first threshold 20 and the second threshold 21, the risk level 25 is set at a first value 250, representative of a first level of risk, considered low for the safety of the electrical assembly 500 and the motor vehicle,

– if the number 1100 of faulty statuses of the security device 5 is greater than or equal to the second threshold 21, the risk level 25 is set at a second value 251, representative of a second level of risk, considered high for the safety of the electrical assembly 500 and of the motor vehicle.

The second step 200 of the method according to the invention is carried out consecutively to the first step 100 of the method according to the invention. More precisely, the second step 200 of the method according to the invention is carried out at the end of the fourth sub-step 104 previously described if the latter is carried out. In the case where the conditions, previously described, are not fulfilled for carrying out the fourth sub-step 104, the second step 200 is carried out consecutively to the third sub-step 103 previously described.

The method according to the invention then advantageously provides for the definition of a third value 252 of the risk level 25, obtained in one or other of the following cases:

- the number 1100 of faulty statuses of the security device 5 is strictly lower than the first threshold 20,

– the level of risk 25 is equal to the first value 250 and the fourth sub-step 104 previously described is carried out, that is to say that the number 1100 of failed statuses of the security device 5 is reset to zero , that is to say also, with reference to the foregoing, that at least one functional status of the securing member 5 has been identified.

- the risk level 25 is equal to the second value 251, and the vehicle is powered up but not started, and the fourth sub-step 104 previously described is carried out, that is to say the number 1100 of faulty statuses of the security member 5 is reset, that is to say also, with reference to the foregoing, that at least one functional status of the security member 5 has been identified.

The third step 300 of the method according to the invention is an alert step, during which a message is sent to a user of the vehicle as soon as the level of risk 25 takes one or the other of the first value 250 or the second value 251 previously described. The invention provides that this alert message is graduated, that is to say that it takes different forms depending on the value of the level of risk 25.

According to an example of implementation, as soon as the risk level 25 takes the first value 250 previously described, that is to say as soon as a risk considered to be low is identified, the alert message consists of the lighting of an indicator representing a service state of the vehicle.

According to this implementation example, as soon as the risk level 25 takes the second value 251 previously described, that is to say as soon as a risk considered to be high is identified, the alert message consists of the lighting of an indicator representative of a state of the electric battery 1, the indicator, previously mentioned, representative of the service status of the vehicle, being extinguished.

Additionally, the aforementioned alert messages can take the form of alert messages displayed on a dashboard of the vehicle. For example, when the risk level 25 is low, a message recommending not to start the vehicle can be displayed, and, when the risk level 25 is high, a message recommending an immediate service of the electrical system of the vehicle. can be displayed.

In a fourth step 400 of the method according to the invention, the data generated during the preceding steps of the method are transferred, for example, to remote servers for the purposes of statistical exploitation and/or analysis of the operation of the vehicle.

In summary, the invention proposes an electrical assembly and a method making it possible to increase the security of a 12 Volt on-board network of a motor vehicle, and, in particular, the continuity, in all circumstances, of the supply of energy. electric to the safety devices allowing, for example, to carry out avoidance and/or emergency braking. Through the method that it proposes, the invention allows monitoring of the device making it possible to guarantee this supply of electrical energy, thus further increasing the operating safety of the vehicle.

Of course, the invention is not limited to the examples which have just been described and many adjustments can be made to these examples without departing from the scope of the invention. In particular, the different characteristics and implementation variants of the invention may be associated with each other in various combinations insofar as they are not incompatible or exclusive of each other. In particular, all the variants and embodiments described above can be combined with each other.

Claims (7)

Electrical assembly (500) of a motor vehicle, the electrical assembly (500) comprising:
- at least one electric battery (1),
- an electric power generator (2) electrically connected to the at least one electric battery (1),
- a plurality of sensors (4) electrically connected to the electric battery (1) and to the electric power generator (2),
- a plurality of electrical devices (3, 30, 31) connected to the at least one electrical battery (1) and to the electrical energy generator (2), the electrical devices (3, 30, 31) comprising electrical devices (31) and standard electrical devices (30),
characterized in that the electrical assembly (500) further comprises a securing member (5) configured to, in the event of detection of a short-circuit on the electrical assembly (500), being able to assume an activated configuration in which the electrical assembly (500) is separated into:
- a first electrical network (501) in which a first part of the security devices is exclusively electrically connected to the electrical energy generator (2), and
- a second electrical network (502) in which a second part of the electrical security devices (31) is exclusively electrically connected to the at least one electrical battery (1). Electrical assembly (500) according to the preceding claim, in which the securing member (5) takes the form of at least one electrical switch which:
- when configured in an inactive configuration, the first electrical network (501) and the second electrical network (502) are electrically connected to each other, and
- when configured in its activated configuration, the first electrical network (501) is isolated from the second electrical network (502). Method for securing an electrical assembly (500) according to any one of the preceding claims, the method being implemented by the securing member (5), the securing method comprising the following steps:
- a step (100) for monitoring the securing device (5), the monitoring step (100) comprising (i) a step (101) for measuring a leakage current (10) at the terminals of each at least one electronic transistor, (ii) a step (102) for qualifying a status (11, 110, 111) of the securing device (5) as a function of the leakage current (10) measured, the status ( 11, 110, 111) reporting the ability of the security device (5) to be able to switch to its activated configuration, the status of the security device (5) taking a first value (110), called faulty, when the security device (5) malfunctions in such a way that it cannot switch to its activated configuration, or a second value (111), called functional, when the security device (5) is able to be able to switch to its activated configuration,
- a step (200) for determining a level of risk (25, 250, 251) linked to the security device (5), the step (200) for determining the level of risk (25, 250, 251 ) comprising a step (103) of counting a number (1100) of faulty statuses, the number (1100) of faulty statuses being stored so as to be able to be incremented at each occurrence, the step (200) of determining the level of risk (25) comprising a step (201) of comparing the number of faulty statuses (1100) counted according to a first threshold (20) and a second threshold (21):
- if the number of failed statuses (1100) is between the first threshold (20) and the second threshold (21), then the risk level (25) is defined at a first risk level (250),
- if the number of faulty statuses (1100) is greater than the second threshold (21), then the risk level (25) is defined at a second risk level (251). Securing method according to the preceding claim, in which the monitoring step (100) includes a step (104) of resetting the number (1100) of faulty statuses to a default value, the resetting step (104) being performed when :
- when the motor vehicle is started, the status of the securing device (5) is functional, or
- While driving the motor vehicle, the status of the securing member (5) is functional. Securing method according to the preceding claim, comprising a step (300) of alerting a user of the motor vehicle according to the level of risk (25, 250, 251) determined, the alerting step (300) comprising the control of at least one light on a dashboard of the motor vehicle. Securing method according to any one of Claims 4 or 5, comprising a step (400) of transferring data generated during the preceding steps of the method, such as for example the number of faulty statuses (1100) when the level of risk ( 25, 250, 251) is equal to the first level (250) or the second level (251). Motor vehicle comprising an electrical assembly according to any one of claims 1 or 2.