ELECTRIC OR HYBRID MOTOR VEHICLE FEATURING A BATTERY MANAGEMENT SYSTEM CONFIGURED TO MAINTAIN 12V NETWORK FUNCTIONS VIA AN ON-BOARD NETWORK

Abstract

The invention relates to an electric or hybrid motor vehicle characterized in that the management system comprises a low drop voltage regulator to ensure standby currents and a first safety device (3) configured to ensure inrush currents or in case of failure of the DC / DC converter (4) and a second safety device (5) powered by the on-board network, said first safety device (3) being electrically connected to a part of the electrochemical cells (2), the second safety device (5) comprising a pre-charge circuit, said first safety device (3) being configured to close when the 12V network voltage is below a predetermined threshold value for a predetermined period of time, the management system comprising wake-up inputs, at least one wake-up output and a 12V output, said at least one wake-up output being configured to wake up the DC / DC converter (4).Figure 2.

Description

Title of the invention: ELECTRIC OR HYBRID MOTOR VEHICLE COMPRISING A BATTERY MANAGEMENT SYSTEM CONFIGURED TO MAINTAIN 12V NETWORK FUNCTIONS VIA AN ON-BOARD NETWORK

[0001] The invention relates to the management of electrical networks by battery management systems of electric or hybrid motor vehicles.

[0002] Prior art is known a utility certificate CN206850490 which describes an intelligently managed charging system for a motor vehicle battery. The charging system comprises a first charging gun and a second charging gun. The first charging gun allows the charging of a first electric motor vehicle, and the second charging gun allows the charging of a second electric motor vehicle, or the first and second charging guns allow the simultaneous charging of the same electric motor vehicle. The charging system includes a CAN bus to supervise the first and second charging guns while delivering an auxiliary 24V / 12V power supply via the charging system. Thus, the presence of a 12V battery in the vehicle is not required. However, a drawback remains.The charging system does not include a safety device to protect the electrical network in the event of a DC / DC converter failure, for example.

[0003] The objective of the present invention is to remedy these drawbacks and to eliminate the 12V battery while maintaining the functions provided by the 12V network.

[0004] To achieve this objective, the invention proposes an electric or hybrid motor vehicle comprising a battery, said vehicle comprising a charging base configured to accommodate a charging means, said vehicle comprising a DC / DC converter, the battery supplying an on-board network and a 12V network, the on-board network having a voltage greater than 12V, the battery comprising a management system and electrochemical cells, notable in that the management system comprises a low-dropout regulator to ensure standby currents, said battery comprising a first safety device capable of opening or closing the electrical circuit of the 12V network in order to ensure inrush currents or in case of failure of the DC / DC converter and a second safety device capable of opening or closing the electrical circuit of the on-board network,said first safety device being electrically connected to a portion of the electrochemical cells, the second safety device comprising a circuit of , precharge, said first safety device being configured to close when the 12V network voltage is below a predetermined threshold value for a predetermined period of time, the management system having wake-up inputs, at least one wake-up output and a 12V output, said at least one wake-up output being configured to wake up the DC / DC converter, said 12V output being configured to cover the standby currents of the 12V network.

[0005] Thanks to the invention, the functions of the 12V network are ensured in the absence of a 12V battery, which makes it possible to lighten the vehicle.

[0006] Advantageously, the on-board network has a voltage of 48V, 400V or 800V.

[0007] Preferably, the first safety device and / or the second safety device is a power switch or contactor.

[0008] This helps to secure the on-board network and avoid disrupting the measurement of the state of charge of the electrochemical cells contained in the battery.

[0009] Advantageously, the 12V output is capable of supplying a maximum current of 300 pA.

[0010] Advantageously, said predetermined threshold value is 10V and said predetermined time period is 10 ms.

[0011] This threshold value ensures the operation of electrical equipment on the 12 V network.

[0012] Furthermore, the invention relates to a method for maintaining the functions of the 12V network by means of an on-board network controlled by a battery management system of an electric or hybrid motor vehicle previously described, characterized in that said method comprises the following steps: - a battery standby stage during which the first safety device is opened, with standby currents being provided by the low voltage drop regulator powered by the on-board network; - a wake-up stage of the management system during which said management system pre-charges itself via the pre-charge circuit of the second safety device powered by the on-board network, the 12V network voltage being below said predetermined threshold value during said predetermined time period so that said first safety device closes following a command issued by the management system, the DC / DC converter waking up to supply the 12V network, said wake-up stage occurring when the charging means is plugged into the charging base or when one of the wake-up inputs of the management system is activated.

[0013] Preferably, during the wake-up step, the wake-up inputs are activatable by a pull-up resistor.

[0014] The invention also relates to a computer program comprising instructions which, when the program is executed by a computer, lead the latter to implement the steps of the method of maintaining the functions of the 12V network by an on-board network controlled by a battery management system of an electric or hybrid motor vehicle previously described.

[0015] The invention will be further detailed by the description of a non-limiting embodiment, and on the basis of the accompanying figures illustrating the invention, in which [Fig.1] schematically illustrates, in the form of a logic diagram, a method of maintaining the functions of the 12V network by an on-board network controlled by a battery management system of an electric or hybrid motor vehicle according to an embodiment of the invention and [Fig.2] schematically illustrates the electrical configuration of the electrical network of the electric or hybrid motor vehicle according to an embodiment of the invention.

[0016] Figure 1 schematically illustrates, in the form of a flowchart, a method for maintaining the functions of the 12V network by an on-board network controlled by a battery management system 1 of an electric or hybrid vehicle. The vehicle includes a charging base suitable for receiving a charging device. For example, the charging device could be the charging gun of a charging cable connected to an external charger 7, a wall outlet, or an electric charging station. Figure 2 schematically illustrates the electrical configuration of the battery. The vehicle includes a DC / DC converter 4 (acronym meaning Direct Current / Direct Current). The DC / DC converter 4 transforms a direct current of a given voltage into a direct current of a different voltage.In the electric or hybrid vehicle, the DC / DC converter 4 converts the high-voltage direct current from the traction battery into a lower-voltage direct current to power the vehicle's various electrical components. In [Fig. 2], the DC / DC converter is electrically connected to the external charger 7. The vehicle's traction battery supplies the vehicle's electrical system and a 12V network, the latter having a voltage higher than 12V. The electrical system notably powers an electric machine 6, or electric motor, of the vehicle, which is necessary for its traction. In this embodiment, the electrical system has a voltage of 48V, but it can also have a voltage of 400V or 800V.The battery management system 1, also known as BMS (Battery Management System), is responsible for centralizing all information related to the battery to extend its lifespan while ensuring optimal performance of the electrical equipment. The management system 1 is powered by all the electrochemical cells 2 of the battery. The system... The battery management system includes a low-dropout (LDO) regulator to ensure standby currents. A low-dropout regulator, also known as an LDO, is an electronic device used to regulate voltage with minimal voltage drop between the input and output. Standby current is the electrical current required to maintain the vehicle's standby functions when the vehicle is stationary or in sleep mode. Typically, standby currents supply power to the instrument panel or safety systems, for example. In addition, the battery includes a first safety device (3) configured to close or open an electrical circuit to ensure inrush currents or to protect the vehicle's electrical system and the 12V network in the event of a DC / DC converter failure. The first safety device (3) is a switch.In another embodiment, the first safety device 3 is a power contactor. The inrush current, also called starting current, is a high current spike occurring when the vehicle is starting or when one of the vehicle's electrical components is switched on. For example, an inrush current is emitted during emergency braking. The electrochemical cells 2 store energy for distribution in the vehicle's electrical system and the 12V network. The first safety device 3 is electrically connected to only some of the electrochemical cells 2, the number of cells varying according to their chemical composition. Furthermore, the first safety device 3 is electrically connected to a 12V charger 8 that supplies the 12V network.The first safety device 3 is normally open, but it is configured to close when the 12V network voltage falls below a predetermined threshold value for a predetermined period of time. Preferably, the predetermined threshold value is 10V and the predetermined period of time is 10 ms. This ensures the operation of the 12V network electrical equipment. The battery shown in [Fig. 2] also includes a second safety device 5 capable of opening or closing the onboard network electrical circuit, particularly to power the electric machine, the DC / DC converter, or other equipment powered by the onboard network. The management system 1 includes wake-up inputs, with wake-up being the output of the management system's sleep state. The second safety device includes a pre-charge circuit.The pre-charge circuit is a device that prepares the electrochemical cells 2 before they are charged. This reduces the risk of damage to the electrochemical cells 2. In addition, the management system 1 includes at least one wake-up output and one 12V output. The wake-up output is configured to wake up the DC / DC converter, while the 12V output... is configured to provide the standby currents from the 12V network. The 12V output is configured to supply a maximum current of 300 pA. The process includes a standby stage E1 during which the battery is in standby mode. Switch 3 is open. The standby currents are therefore provided by the low-dropout regulator, which is itself powered by the vehicle's electrical system. When the charging device is inserted into the vehicle's charging port or when one of the wake-up inputs of the management system 1 is activated, the management system enters the wake-up phase during a wake-up stage E2. The wake-up input of the management system 1 can be activated, in particular, by a pull-up resistor. The pull-up resistor is a resistor that allows a signal to be drawn towards the supply voltage when no other component is activated, for example, when a switch is closed.The wake-up phase is characterized by a pre-charge of the control system 1 via the pre-charge circuit of the second safety device 5, which is powered by the onboard network. The 12V network voltage decreases until it falls below the predetermined threshold value during the predetermined time period, i.e., 10V for 10 ms in this embodiment. The control system 1 then issues a command to close the switch 3. Thus, the DC / DC converter 4 wakes up to ensure the 12V network power supply is maintained.

Claims

Demands

1. Electric or hybrid motor vehicle comprising a battery, said vehicle comprising a charging base configured to accommodate a charging means, said vehicle comprising a DC / DC converter (4), the battery supplying an on-board network and a 12V network, the on-board network having a voltage greater than 12V, the battery comprising a management system (1) and electrochemical cells (2), characterized in that the management system (1) comprises a low-dropout regulator to ensure standby currents, said battery comprising a first safety device (3) capable of opening or closing the electrical circuit of the 12V network in order to ensure inrush currents or in case of failure of the DC / DC converter (4) and a second safety device (5) capable of opening or closing the electrical circuit of the on-board network,said first safety device being electrically connected to a portion of the electrochemical cells (2), the second safety device (5) comprising a pre-charge circuit, said first safety device (3) being configured to close when the 12V network voltage is below a predetermined threshold value for a predetermined period of time, the management system (1) comprising wake-up inputs, at least one wake-up output and a 12V output, said at least one wake-up output being configured to wake up the DC / DC converter, said 12V output being configured to cover the standby currents of the 12V network.

2. Vehicle according to claim 1 characterized in that the on-board network has a voltage of 48V, 400V or 800V.

3. Vehicle according to claim 1 or 2 characterized in that the first safety device (3) and / or the second safety device (5) is a power switch or contactor.

4. Vehicle according to any one of claims 1 to 3 characterized in that the 12V output is capable of supplying a maximum current of 300 pA.

5. Vehicle according to any one of claims 1 to 4 characterized in that said predetermined threshold value is 10V and said predetermined time period is 10 ms.

6. Method of maintaining the functions of the 12V network by an on-board network controlled by a management system (1) of a battery of an electric or hybrid motor vehicle according to any one of claims 1 to 5, characterized in that said method comprises the following steps: - a standby step (El) of the battery during which the first safety device (3) is opened, the standby currents being ensured by the low drop voltage regulator supplied by the on-board network;- a wake-up step (E2) of the management system (1) during which said management system (1) pre-charges itself via the pre-charge circuit of the second safety device (5) powered by the on-board network, the 12V network voltage being lower than said predetermined threshold value during said predetermined time period so that said first safety device (3) closes following a command issued by the management system (1), the DC / DC converter (4) waking up to supply the 12V network, said wake-up step occurring when the charging means is plugged into the charging base or when one of the wake-up inputs of the management system (1) is activated.;

7. Method according to claim 6 characterized in that, during the wake-up step (E2), the wake-up inputs are activatable by a pull-up resistor.

8. Computer program comprising instructions which, when the program is executed by a computer, cause the computer to implement the steps of the method of maintaining the functions of the 12V network by an on-board network controlled by a management system (1) of a battery of an electric or hybrid motor vehicle according to claims 6 to 7.

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