METHOD FOR MONITORING THE TEMPERATURE OF MODULES IN A BATTERY OF AN ELECTRIC OR HYBRID MOTOR VEHICLE

Abstract

The invention relates to a method for monitoring the temperature of modules in a battery of an electric or hybrid motor vehicle, comprising a temperature measurement step (E1) by each temperature sensor of each module; a fault detection step (E2) when at least one of the measured temperature values ​​is below a minimum threshold value or above a maximum threshold value; and a warning step (E3) during which the driver is warned when at least one of the modules has a single fault, or during which power is limited and authorization to open the battery contacts is requested when at least one of the modules has multiple faults. Figure 1

Description

Title of the invention: METHOD FOR MONITORING THE TEMPERATURE OF MODULES IN A BATTERY OF AN ELECTRIC OR HYBRID MOTOR VEHICLE

[0001] The invention relates to electric or hybrid motor vehicles, and more particularly to the batteries of these vehicles.

[0002] Prior art patent application WO2023111408 is known, describing a method for monitoring the operation of temperature sensors in several modules of a vehicle battery. Each module comprises a plurality of cells. The method includes a step of receiving the temperature values ​​of said cells measured by each temperature sensor and a step of measuring a temperature difference between the temperature values ​​and a reference temperature value. If the difference exceeds a predetermined threshold, the vehicle driver is alerted to the malfunction of one of the temperature sensors. However, some drawbacks remain. The reference temperature is limited to a precise temperature rather than a temperature range. The tolerance for detecting the malfunction is therefore reduced. Furthermore, the malfunction is detected when a temperature sensor exhibits a deviation exceeding the predetermined threshold.However, if only one of the temperature sensors shows an excessive temperature, but the battery module's temperature allows for safe operation, then there is no need to warn the driver. Finally, the position of each temperature sensor is not recorded. Therefore, if a faulty temperature sensor needs repair, the entire module, or even the entire battery, may need to be replaced.

[0003] The objective of the present invention is to remedy these drawbacks, in particular to monitor the temperature of each battery module and to make the battery safe according to the temperature of these modules.

[0004] To achieve this objective, the invention proposes a method for monitoring the temperature of modules in a battery of an electric or hybrid motor vehicle, said vehicle comprising an electric motor, a driver warning system, a powertrain, and an electronic management system, said battery being configured to deliver power to said electric motor, said battery comprising contactors configured to close to transmit electrical energy to said electric motor or to open to interrupt the transmission of electrical energy to said electric motor, the powertrain comprising a supervisor, said electronic management system comprising a read-only memory device, each battery module comprising a plurality of temperature sensors, the position of each temperature sensor being predefined in said read-only memory device, each module of said battery being configured to operate at a temperature between a minimum threshold value and a maximum threshold value, notable in that said method comprises the following steps: - a step of measuring the temperature by each temperature sensor of each module and of transmitting a temperature value measured by each temperature sensor of each module to the electronic management system, said measurement step being repeated at a predetermined frequency; - a fault detection step when at least one of the measured temperature values ​​is below said minimum threshold value or when at least one of the measured temperature values ​​is above said maximum threshold value; - a warning step for said driver by said warning means and recording of said fault in said read-only memory device when at least one of the modules has a single fault during a first predetermined control period, said electronic management system being in a first configuration, or a warning step for said driver by said warning means, recording of said fault in said read-only memory device, limiting of power to a first power value by the electronic management system and a request for authorization to open the battery contactors to the supervisor by the electronic management system to electrically isolate said battery when at least one of the modules has at least two faults during a second predetermined control period, said electronic management system being in a second configuration.

[0005] Thanks to the invention, the temperature of each battery module is monitored. If a fault occurs, an appropriate response ensures the safety of vehicle users.

[0006] Preferably, said minimum threshold value is equal to -40°C and said maximum threshold value is equal to 120°C.

[0007] Advantageously, during said warning step, the first power value is reached during a first predetermined maximum duration.

[0008] Advantageously, said vehicle includes a regenerative braking system delivering electrical energy of a second power value to said battery and, during said warning stage, said electronic management system limits said second power value, said second power value being reached during a second predetermined maximum duration.

[0009] Modules with a defect will overheat exponentially if the measures taken during the warning stage are delayed. Thus, the The risk of battery damage is reduced, and its lifespan is therefore improved. Furthermore, the risk of battery fire is reduced.

[0010] Preferably, said first power value and said second power value are zero.

[0011] Zero power, i.e. the complete cessation of the transmission of electrical energy, is the most effective way to avoid the aggravation of the detected fault(s).

[0012] Preferably, when the vehicle battery is being recharged with electrical energy and, during said warning step, the electronic management system commands the supervisor to immediately stop the electrical energy recharging.

[0013] It is therefore easy to cool a battery when it is not being recharged.

[0014] Advantageously, during said warning step, the electronic management system opens the battery contactors after a third predetermined duration in the absence of authorization or in the event of refusal by the supervisor.

[0015] Thus, in the event of a malfunction of the supervisor, the battery is still electrically isolated in order to protect the users of said vehicle.

[0016] Advantageously, said method comprising a reconfiguration step after said warning step during which the electronic management system switches from the second configuration to the first configuration when said cooling system is activated and at least one module has a single fault.

[0017] The battery can then operate safely although the fault is not yet fully resolved.

[0018] Advantageously, when said cooling system is activated, said process comprising a recovery step after said warning step when the electronic management system is in the first configuration and no fault is detected during a first predetermined recovery time or when the electronic management system is in the second configuration and no fault is detected during a second predetermined recovery time.

[0019] In the event of momentary overheating which does not affect the safety of the vehicle's users, the battery is again able to function correctly and safely.

[0020] Preferably, said first predetermined recovery time is equal to 3000 ms and said second predetermined recovery time is equal to 5000 ms.

[0021] The invention will be further detailed by the description of a non-limiting embodiment, and on the basis of the attached figure illustrating the invention, in which [Fig.1] schematically illustrates, in the form of a flowchart, a method for monitoring the temperature of modules of a battery of an electric or hybrid motor vehicle according to an embodiment of the invention.

[0022] A method for monitoring the temperature of modules in a battery of an electric or hybrid motor vehicle is schematically illustrated in Figure 1 in the form of a flowchart. The vehicle has an electric motor. The battery stores electrical energy and distributes it to the electric motor. The battery is configured to deliver power to the electric motor. The battery comprises a plurality of modules. Each battery module has a plurality of temperature sensors. Each module of the battery is configured to operate at a temperature between a minimum and a maximum threshold value. The battery includes contactors configured to close in order to transmit electrical energy to the electric motor or to open in order to interrupt the transmission of electrical energy to the electric motor.The vehicle includes a powertrain and an electronic management system. The electronic management system centralizes all charge and temperature information for the battery to extend its lifespan while ensuring optimal performance. The electronic management system comprises a supervisor and a read-only memory (ROM). The supervisor monitors and controls the overall operation of the electronic management system. It interacts with other vehicle components to ensure safe and optimal vehicle operation. The ROM stores essential and permanent data about the battery's operation. Unlike random-access memory (RAM), ROM does not require a continuous power supply to retain its data.Thus, the read-only memory (ROM) retains this data even when the electronic management system is powered off. This is particularly useful for diagnostics. The occurrence of an event is saved, so if the vehicle breaks down, a technician can access the ROM data to perform a diagnosis. Furthermore, the vehicle includes a driver warning system. During a measurement step (El), each temperature sensor measures the temperature. The temperature value measured by each sensor is then transmitted to the electronic management system. The measurement step (El) is repeated at a predetermined frequency.During an E2 detection step, a fault is detected when at least one of the measured temperature values ​​is below the minimum threshold value or when at least one of the measured temperature values ​​is above the maximum threshold value. Preferably, the minimum threshold value is -40°C and the maximum threshold value is 120°C. The position of each temperature sensor is recorded in the read-only memory device. Thus, if a temperature sensor is faulty, it is possible to... to locate and replace it, without having to replace the entire module. During an E3 warning stage, when at least one of the battery modules exhibits a single fault during a first predetermined monitoring period, the electronic management system enters a first configuration. The first configuration is characterized by the recording of the fault in the read-only memory device and the warning of the driver via the warning means. For example, the vehicle has an instrument panel, and the warning means is a warning light illuminating on the instrument panel. When at least one of the battery modules exhibits at least two faults during a second predetermined monitoring period, the electronic management system enters a second configuration.The second configuration is characterized by fault recording in the read-only memory device, warning the driver, and limiting the power that can be delivered from the battery to the electric motor to a first power value by the electronic management system. Advantageously, this first power value is reached within a first predetermined maximum duration. Preferably, this first maximum duration is 1 minute. Finally, authorization to open the battery contactors is requested from the supervisor by the electronic management system. Preferably, the electronic management system itself commands the opening of the battery contactors after a third predetermined duration if authorization is not granted by the supervisor or if the supervisor refuses authorization.Advantageously, when the electronic management system is in the second configuration and the vehicle has a regenerative braking system that delivers electrical energy at a second power level to the battery, the electronic management system limits this second power level. The regenerative braking system is used in electric or hybrid vehicles to recover some of the kinetic energy during braking and convert it into electrical energy to recharge the battery. The generative braking system increases the vehicle's range. Preferably, both the first and second power levels are zero. The second power level is reached within a second predetermined maximum duration. Preferably, this second predetermined maximum duration is 1 minute.Advantageously, when the vehicle's battery is being recharged, the electronic management system commands the supervisor to immediately stop the recharging process. Advantageously, the battery includes a cooling system, and the process includes a reconfiguration step after the E3 warning step, during which the electronic management system switches from the second configuration to the first configuration when the battery is recharged. The cooling system is activated, causing a decrease in the temperature of the battery modules, and this occurs when at least one module has a single fault. The cooling system is an air-cooling, liquid-cooling, or hybrid system. The role of the cooling system is to prevent the battery from overheating in order to maintain optimal operating conditions and thus ensure the performance and durability of the vehicle. Initially, the electronic management system is in the second configuration because it has at least two faults in at least one of the modules. The temperature decreases due to the activation of the cooling system. The electronic management system then detects only one fault in at least one of the modules, which results in the electronic management system changing its configuration to the first configuration.Advantageously, the battery includes said cooling system, and the process includes a recovery step when the electronic management system is in the first configuration and no fault is detected during a first predetermined recovery time, or when said electronic management system is in the second configuration and no fault is detected during a second predetermined recovery time. The recovery step is performed after said warning step E3. Preferably, said first predetermined recovery time is equal to 3000 ms and said second predetermined recovery time is equal to 5000 ms.

Claims

1. Demands A method for monitoring the temperature of modules in a battery of an electric or hybrid motor vehicle, said vehicle comprising an electric motor, a driver warning means, a powertrain, and an electronic management system, said battery being configured to deliver power to said electric motor, said battery comprising contactors configured to close to transmit electrical energy to said electric motor or to open to interrupt the transmission of electrical energy to said electric motor, the powertrain comprising a supervisor, said electronic management system comprising a read-only memory device, each battery module comprising a plurality of temperature sensors, the position of each temperature sensor being predefined in said read-only memory device,each module of said battery being configured to operate at a temperature between a minimum threshold value and a maximum threshold value, characterized in that said method comprises the following steps: - a measurement step (El) of the temperature by each temperature sensor of each module and of transmission of a temperature value measured by each temperature sensor of each module to the electronic management system, said measurement step being repeated at a predetermined frequency; - a fault detection step (E2) when at least one of the measured temperature values ​​is below said minimum threshold value or when at least one of the measured temperature values ​​is above said maximum threshold value; - a warning step (E3) of said driver by said warning means and recording of said fault in said read-only memory device when at least one of the modules presents a single fault during a first predetermined control period, said electronic management system being in a first configuration, or a warning step of said driver by said warning means, recording of said fault in said read-only memory device, limitation of power to a first power value by the electronic management system and a request for authorization to open the battery contacts upon- monitor by the electronic management system to electrically isolate said battery when at least one of the modules has at least two faults during a second predetermined control period, said electronic management system being in a second configuration.

2. A method according to claim 1 characterized in that said minimum threshold value is equal to -40°C and said maximum threshold value is equal to 120°C.

3. Method according to claim 1 or 2 characterized in that, during said warning step (E3), the first power value is reached during a first predetermined maximum duration.

4. Method according to claim 3 characterized in that said vehicle comprises a regenerative braking system delivering electrical energy of a second power value to said battery and, during said warning stage (E3), said electronic management system limits said second power value, said second power value being reached during a second predetermined maximum duration.

5. A method according to claim 4 characterized in that said first power value and said second power value are zero.

6. A method according to any one of claims 3 to 5 characterized in that when the vehicle battery is being recharged with electrical energy and, during said warning step (E3), the electronic management system commands the supervisor to immediately stop the electrical energy recharging.

7. A method according to any one of claims 1 to 6 characterized in that, during said warning step (E3), the electronic management system opens the battery contactors after a third predetermined duration in the absence of authorization or in the event of refusal by the supervisor.

8. A method according to any one of claims 1 to 7 characterized in that the battery comprises a cooling system, said method comprising a reconfiguration step after said warning step (E3) during which the electronic management system switches from the second configuration to the first configuration when said cooling system is activated and at least one module has a single fault.

9. The method according to claim 8, characterized in that when said cooling system is activated, said process including a recovery step after said warning step (E3) when the electronic management system is in the first configuration and no fault is detected during a first predetermined recovery time or when the electronic management system is in the second configuration and no fault is detected during a second predetermined recovery time.

10. The method according to claim 9 characterized in that said first predetermined recovery time is equal to 3000 ms and said second predetermined recovery time is equal to 5000 ms.

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