MOTOR VEHICLE COMPRISING A MEANS FOR TRANSFERRING ENERGY FROM BATTERIES IN THE STANDBY PHASE, AND A MEANS FOR RESTRICTING THE TRANSFER, METHOD AND PROGRAM BASED ON SUCH A VEHICLE

Abstract

The invention relates to a motor vehicle comprising:- a traction battery (HV);- an accessory battery (B) connected to the traction battery (HV), the accessory battery (B) performing several electrical power supply functions (A) in the motor vehicle;- a transfer means for performing an energy transfer by using a portion of the electrical energy of the traction battery to recharge the accessory battery (B) in the standby phase;- a control means (CT) for controlling the recharging of the accessory battery (B) by the traction battery (HV), and for determining a malfunction of the energy transfer (C);- a function restriction means for deactivating one or more functions of the accessory battery (B) in the event of a malfunction of the energy transfer (C). The invention also relates to a method and a program based on such a vehicle. Abstract figure: Fig. 1

Description

Title of the invention: MOTOR VEHICLE COMPRISING A MEANS FOR TRANSFERRING ENERGY FROM BATTERIES IN THE STANDBY PHASE, AND A MEANS FOR RESTRICTING THE TRANSFER, METHOD AND PROGRAM BASED ON SUCH A VEHICLE

[0001] The invention relates to the field of electricity management of electric vehicles and hybrid vehicles, and more particularly the management of the charging of low-voltage batteries of such vehicles.

[0002] During the standby phase of this type of vehicle, for example in a parking lot or other, a so-called 12V battery (or low-voltage battery) provides all the power supply to the vehicle components and ancillary services, such as detection for hands-free access, a remote service (or "remote service" in English) such as locking / unlocking the doors, programming the battery charge, updating the on-board software, thermal preconditioning, 4G communication, etc.).

[0003] It is therefore necessary to manage the energy available in the accessory battery.

[0004] The first solution of the prior art is energy transfer (or "balancing" in English), that is to say the transfer of electrical energy from a traction battery (called high voltage) to the accessory battery for an electric vehicle. Thus, the accessory battery is recharged using the energy from the traction battery.

[0005] A second solution is to minimize the energy consumption in operation of these ancillary services.

[0006] A third solution is the programmed restriction of these accessory services to consume less energy.

[0007] It is also possible to minimize / optimize the energy consumption of these functions or restrict the use of these functions.

[0008] Unfortunately, the energy transfer does not work under all conditions, for example when the traction battery is not sufficiently charged, the outside temperature is too low, etc.

[0009] Furthermore, minimizing the energy consumption of operating services should be done as much as possible, but sometimes there are physical limits, or it requires several complex components.

[0010] The restriction of services programmed after a certain duration does not take into account the energy available in the accessory battery. This implies a risk of restrict services when it is not necessary.

[0011] An objective of the present invention is to remedy the defects of the prior art, and in particular to propose a solution for optimizing the use of the accessory battery via the energy of the traction battery.

[0012] To achieve this objective, the invention proposes a motor vehicle comprising: - a traction battery; - an accessory battery connected to the traction battery, the accessory battery performing several electrical power supply functions in the motor vehicle; - a transfer means for carrying out an energy transfer by using part of the electrical energy of the traction battery to recharge the accessory battery in the standby phase; - a control means for controlling the recharging of the accessory battery by the traction battery, and for determining a malfunction of the energy transfer; - a function restriction means to disable one or more functions of the accessory battery in the event of a power transfer malfunction.

[0013] Advantageously, the idea is to restrict the various services if the energy transfer does not work or experiences problems. The restriction of the services is triggered on a criterion of charge state of the accessory battery or time after detection of a malfunction of the energy transfer. If the energy transfer works well (charge state of the accessory battery above a certain level for example) then the services are not restricted.

[0014] According to a variant, the control means controls the state of charge of the accessory battery, and determines a malfunction of the energy transfer if said state of charge is below a threshold.

[0015] This makes it possible to simply assess a malfunction in the energy transfer.

[0016] According to a variant, the control means is connected to a cloud network which comprises a means for estimating the state of charge of the accessory battery.

[0017] This makes it possible to estimate the state of charge for this function with the vehicle on standby, without needing to prematurely use the vehicle's energy and the corresponding electronic systems. This also makes it possible to limit the hardware and software requirements, and the calculation times of the accessory battery.

[0018] According to a variant, the control means comprises said transfer means and said restriction means.

[0019] This allows a controller to be used to check the status of the power transfer and limit the functions of the accessory battery.

[0020] According to a variant, the restriction means deactivates all of said functions in a synchronized manner, based on a criterion of charge state of the accessory battery.

[0021] This saves maximum energy from the accessory battery.

[0022] According to a variant, the restriction means deactivates said functions in an orderly manner, based on a criterion of charge state of the accessory battery.

[0023] This allows different functions of the accessory battery to be maintained according to several specific state of charge thresholds.

[0024] According to a variant, the restriction means deactivates said functions in an orderly manner, based on a duration criterion.

[0025] This allows certain functions of the accessory battery to be retained for longer than others depending on the required usage times of the functions.

[0026] The invention further relates to a battery control method for a motor vehicle according to the invention, comprising: - a transfer step for carrying out an energy transfer by using part of the electrical energy from the traction battery to recharge the accessory battery in the standby phase; - a control step to control the recharging of the accessory battery by the traction battery, and to determine a malfunction of the energy transfer; - a function restriction step to disable one or more functions of the accessory battery in the event of a power transfer malfunction.

[0027] Another object of the invention relates to a computer program comprising program code instructions for executing the steps of the control method according to the invention, when said program operates on a computer.

[0028] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which: - [Fig.l] schematically illustrates the elements of the motor vehicle according to the invention, when the energy transfer is operating; - [Fig.2] schematically illustrates the elements of [Fig.l], when the energy transfer does not work; - [Fig.3] schematically illustrates changes over time in charge states and charge state thresholds during operation of the invention.

[0029] The invention proposes a solution to avoid restricting the services when it is not necessary, when the 12V battery B (or low voltage battery) is discharged. Thus, the occurrences of restriction of the services and power supplies of functions are reduced, and the energy available in the 12V battery B is managed in an optimized manner with the need of the services and functions.

[0030] The invention proposes an optimized strategy for managing the energy of the 12V battery B and the services available to the user (accessory power supply functions A). The restriction of the services is only activated in the event of an energy too low available in the 12V B battery (here, in the event of non-functioning or malfunctioning energy transfer). Restricting services is then only a backup solution if the energy transfer does not work.

[0031] This is in particular a “software” solution for energy management without modifying the size of the 12V B battery. This makes it possible to offer a number of services to the user in an optimized manner with the available energy.

[0032] During the standby phase of the vehicle, for example in a parking lot or other, energy is consumed from the 12V B battery for a certain number of services (detection for hands-free access, remote service such as locking / unlocking the doors, programming battery charging, updating the on-board software, thermal preconditioning, 4G communication, etc.

[0033] Concerning the energy transfer C, in an electrified vehicle (with an HV traction battery, called high voltage), the energy transfer C comprises a transfer of electrical energy from this HV traction battery to the 12V battery B which provides numerous functions A in the vehicle. A control means CT, such as a controller, may be provided for this purpose. It controls the energy transfer C. This energy transfer C takes place in the standby phase, that is to say when the vehicle is not being used for travel (engine off).

[0034] The strategy is as follows: If the energy transfer C works well then the state of charge of the 12V battery B remains at a good level (above a state of charge threshold SI). In this case, there is no restriction on the service and functions of power supplies A. The energy transfer lasts for example 2 hours (C=2 hours).

[0035] If the energy transfer does not work or works poorly (we will speak of a NC malfunction), for example because the outside temperature is too low or a low state of charge of the HV traction battery) then the state of charge SOC of the 12V battery B drops and is no longer at a good level (in particular falls below one or said threshold SI). In this case, the NA restrictions of services and power supplies A are activated. Preferably, one or said CT control means is provided for this purpose. It controls the NA restrictions of power supplies A.

[0036] After a malfunction or non-operation NC of the energy transfer C, the service restriction NA can be done in at least one of the following ways: - in a synchronized manner (all power supply functions A at the same time) on a battery state of charge criterion at 12V B (for example said state of charge threshold SI, which may be 75% SOC; - in an orderly manner (one power supply function A after the other) on a duration criterion (We deactivate one function A every 2 days for example); - in an orderly manner (one power function A after the other) on a criterion battery charge status at 12V B (1 service is deactivated at each charge status threshold), or several specific thresholds.

[0037] For example, the access services (locking) are maintained for 7 days up to a threshold of 69% of SOC, and the power supply to the corresponding antennas is then cut off, with the exception of the NFC antennas.

[0038] The memories are maintained for 3 days up to a threshold of 76% SOC.

[0039] Remote services are maintained for 7 days up to a threshold of 69% SOC.

[0040] GSM network services are maintained for 7 days up to a threshold of 69% SOC, and mobile data services (4G) are maintained for 1 day up to a threshold of 83% SOC.

[0041] [Fig.3] illustrates a simplified diagram of the state of charge of the 12V battery B in the different cases. The zigzag curve represents normal operation. When the state of charge reaches the threshold SI, the energy transfer provides energy and raises the state of charge. In this case the power supply functions A are maintained.

[0042] When the state goes below the SI threshold at 75% SOC, the NA restrictions prevent or even limit the A power supply functions.

[0043] The NCI curve shows a state of charge that decreases without exceeding a critical threshold S2, for example at 45% SOC. The NC2 curve shows a state of charge that decreases and exceeds the critical threshold S2. In this case, a request R can be sent to a maintenance service to check the state of the battery at 12V B.

[0044] For this optimized strategy of the energy of the 12V battery B, one of the variants would be to use the estimation of the state of charge by the cloud network (or "cloud" in English). With this solution, the size and complexity of the 12V battery B are optimized.

[0045] Thus, there is an optimization between the available energy and the services for the user. The invention therefore involves fewer service restrictions, and thus more satisfied users.

[0046] The invention also relates to a battery control method comprising steps of implementing the elements described above.

[0047] Another object of the invention relates to a computer program for implementing a method as described above. The program can be loaded into the memory of at least one controller, for example a 12V battery controller B.

Claims

Claims

1. Motor vehicle comprising: - a traction battery (HV); - an accessory battery (B) connected to the traction battery (HV), the accessory battery (B) performing several electrical power supply functions (A) in the motor vehicle; - a transfer means for performing an energy transfer by using a portion of the electrical energy from the traction battery to recharge the accessory battery (B) in the standby phase; - a control means (CT) for controlling the recharging of the accessory battery (B) by the traction battery (HV), and for determining a malfunction (NC) of the energy transfer (C); - a function restriction means for deactivating (NA) one or more functions of the accessory battery (B) in the event of a malfunction (NC) of the energy transfer (C).

2. Motor vehicle according to claim 1, characterized in that the control means (CT) controls the state of charge (SOC) of the accessory battery (B), and determines a malfunction (NC) of the energy transfer if said state of charge (SOC) is below a threshold (SI).

3. Motor vehicle according to claim 2, characterized in that the control means is connected to a cloud network which comprises means for estimating the state of charge of the accessory battery.

4. Motor vehicle according to any one of claims 1 to 3, characterized in that the control means (CT) comprises said transfer means and said restriction means.

5. Motor vehicle according to any one of claims 1 to 4, characterized in that the restriction means deactivates (NA) all said functions (A) in a synchronized manner, on a state of charge criterion (SOC) of the accessory battery (B).

6. Motor vehicle according to any one of claims 1 to 4, characterized in that the restriction means deactivates (NA) said functions (A) in an orderly manner, on a state of charge criterion (SOC) of the accessory battery (B).

7. Motor vehicle according to any one of claims 1 to 4, characterized in that the restriction means deactivates (NA) said functions (A) in an orderly manner, on a duration criterion (D).

8. Battery control method for a motor vehicle according to one of

9. any of claims 1 to 7, comprising: - a transfer step for carrying out an energy transfer using part of the electrical energy of the traction battery (HV) to recharge the accessory battery (B) in the standby phase; - a control step to control the recharging of the accessory battery (B) by the traction battery (HV), and to determine a malfunction (NC) of the energy transfer (C); - a function restriction step to deactivate (NA) one or more functions of the accessory battery in the event of a malfunction (NC) of the energy transfer (C). A computer program comprising program code instructions for executing the steps of the control method according to claim 8, when said program is running on a computer.

Images