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

Abstract

The invention relates to a method for monitoring the temperature of modules of a battery of an electric or hybrid motor vehicle comprising a step (E1) of measuring the temperature by each temperature sensor of each module; a step (E2) of detecting a fault when at least one of the measured temperature values ​​is lower than a minimum threshold value or higher than a maximum threshold value; a warning step (E3) during which a warning is given to the driver when at least one of the modules has a single fault or during which a limitation of the power is carried out and a request for authorization to open the battery contactors is made when at least one of the modules has several faults. Figure 1

Description

Title of the invention: METHOD FOR MONITORING THE TEMPERATURE OF MODULES OF 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] Known from the prior art is a patent application WO2023111408 which describes a method for monitoring the operation of the temperature sensors of several modules of a vehicle battery. Each module comprises a plurality of cells. The method comprises 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 is greater than a predetermined threshold, the driver of the vehicle is alerted to the malfunction of one of the temperature sensors. However, disadvantages remain. The reference temperature is limited to a specific temperature rather than a temperature range. The tolerance for detecting the malfunction is therefore reduced. In addition, the malfunction is detected when a temperature sensor has a difference greater than the predetermined threshold.However, if only one of the temperature sensors is overheated, but the battery module is at a temperature that allows it to operate safely, 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 to be repaired, it is necessary to replace the entire module, or even the entire battery.

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

[0004] To achieve this objective, the invention proposes a method for monitoring the temperature of modules of a battery of an electric or hybrid motor vehicle, said vehicle comprising an electric motor, a means for warning a driver, 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, remarkable in that said method comprises the following steps: - a step of measuring the temperature by each temperature sensor of each module and transmitting a temperature value measured by each temperature sensor of each module to the electronic management system, said measuring step being repeated at a predetermined frequency; - a step of detecting a fault when at least one of the measured temperature values ​​is lower than said minimum threshold value or when at least one of the measured temperature values ​​is higher than said maximum threshold value; - a step of warning said driver by said warning means and recording 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 step of warning said driver by said warning means, recording said fault in said read-only memory device, limiting the power to a first power value by the electronic management system and requesting authorization for opening the battery contactors from 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 comprises a regenerative braking system delivering electrical energy of a second power value to said battery and, during said warning step, 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 fault will overheat exponentially if the measures taken during the warning stage are carried out late. Thus, the The risk of battery damage is reduced, and its lifespan is therefore improved. In addition, the risk of the battery catching fire is reduced.

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

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

[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 recharging with electrical energy.

[0013] It is thus 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 comprises 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 completely resolved.

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

[0019] In the event of temporary overheating that does not affect the safety of vehicle users, the battery is once 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 appended figure illustrating the invention, in which [Fig.l] 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] [Fig.l] 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. The vehicle comprises an electric motor. The battery allows the storage of electrical energy and the distribution of electrical energy to said electric motor. The battery is configured to deliver power to said electric motor. The battery comprises a plurality of modules. Each battery module comprises a plurality of temperature sensors. Each module of said battery is configured to operate at a temperature between a minimum threshold value and a maximum threshold value. The battery comprises contactors configured to close in order to transmit electrical energy to said electric motor or to open in order to interrupt the transmission of electrical energy to said electric motor.The vehicle includes a powertrain and an electronic management system. The electronic management system centralizes all the charge and temperature information of the battery to extend the battery's life while ensuring optimal performance. The electronic management system includes a supervisor and a read-only memory device. The supervisor is a component that monitors and controls the overall operation of the electronic management system. The supervisor interacts with other components of the vehicle to ensure safe and optimal operation of the vehicle. The read-only memory device stores essential and permanent data on the operation of the battery. The specificity of read-only memory, compared to random access memory, is that it does not require a continuous electrical power supply to store said data.Thus, the read-only memory retains said data even when the electronic management system is switched off. This is particularly useful for diagnostics. Indeed, the occurrence of an event is saved. Thus, if the vehicle breaks down, a technician is able to consult the data in the read-only memory to establish a diagnosis. In addition, said vehicle comprises a means for warning a driver of said vehicle. During a measurement step E1, each temperature sensor measures the temperature. The temperature value measured by each temperature sensor is then transmitted to said electronic management system. The measurement step E1 is repeated at a predetermined frequency.In a detection step E2, a fault is detected when at least one of the measured temperature values ​​is lower than said minimum threshold value or when at least one of the measured temperature values ​​is higher than said maximum threshold value. Preferably, the minimum threshold value is equal to -40°C and said maximum threshold value is equal to 120°C. The position of each temperature sensor is recorded in said read-only memory device. Thus, if a temperature sensor is defective, it is possible to . locate it to replace it, without having to replace said module entirely. During a warning step E3, when at least one of the battery modules has a single fault during a first predetermined control period, said electronic management system enters a first configuration. The first configuration is characterized by recording the fault in said read-only memory device and warning the driver by said warning means. For example, the vehicle has a dashboard and said warning means is a warning light that comes on on the dashboard of said vehicle. When at least one of the battery modules has at least two faults during a second predetermined control period, said electronic management system enters a second configuration.The second configuration is characterized by recording faults in said read-only memory device, by warning the driver, by limiting the power that can be delivered by the battery to said electric motor to a first power value by the electronic management system. Advantageously, said first power value is reached during a first predetermined maximum duration. Preferably, the first maximum duration is equal to 1 min. Finally, authorization to open the contactors of said battery is requested from the supervisor by said electronic management system. Preferably, the electronic management system itself controls the opening of the contactors of said battery after a third predetermined duration in the absence of authorization by the supervisor or in the event of refusal by the supervisor.Advantageously, when the electronic management system is in the second configuration and the vehicle comprises a regenerative braking system delivering electrical energy of a second power value to said battery, the electronic management system limits said second power value. The regenerative braking system is a system used in electric or hybrid vehicles to recover part of the kinetic energy during braking to convert it into electrical energy allowing said battery to be recharged. The generative braking system makes it possible to increase the autonomy of the vehicle. Preferably, the first power value and said second power value are zero. The second power value is reached during a second predetermined maximum duration. Preferably, said second predetermined maximum duration is equal to 1 min.Advantageously, when the battery of said vehicle is being recharged with electrical energy, the electronic management system commands the immediate stopping of the recharging with electrical energy to the supervisor. Advantageously, said battery comprises a cooling system and the method comprises a reconfiguration step after said warning step E3 during which said electronic management system switches from the second configuration to the first configuration when said . The cooling system is activated, which causes the temperature in the battery modules to decrease, and when at least one module has a single fault. The cooling system is an air, liquid, or mixed cooling system. The role of the cooling system is to prevent the battery from overheating to maintain optimal operating conditions and thus ensure the performance and durability of said 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 therefore only detects a single fault in at least one of the modules, which has the effect of changing the configuration of said electronic management system to the first configuration.Advantageously, the battery comprises said cooling system and the method comprises a restoration step when the electronic management system is in the first configuration and no fault is detected during a first predetermined restoration time or when said electronic management system is in the second configuration and no fault is detected during a second predetermined restoration time. The restoration step is carried out after said warning step E3. Preferably, said first predetermined restoration time is equal to 3000 ms and said second predetermined restoration time is equal to 5000 ms.

Claims

1. Claims A method for monitoring the temperature of modules of a battery of an electric or hybrid motor vehicle, said vehicle comprising an electric motor, a means for warning a driver, 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 step (El) of measuring the temperature by each temperature sensor of each module and transmitting a temperature value measured by each temperature sensor of each module to the electronic management system, said measuring step being repeated at a predetermined frequency; - a step (E2) of detecting a fault when at least one of the measured temperature values ​​is lower than said minimum threshold value or when at least one of the measured temperature values ​​is higher than said maximum threshold value; - a step (E3) of warning said driver by said warning means and recording 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 step of warning said driver by said warning means, recording said fault in said read-only memory device, limiting the power to a first power value by the electronic management system and requesting authorization to open the battery contactors at the su- monitored 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 monitoring period, said electronic management system being in a second configuration.

2. 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 step (E3), said electronic management system limits said second power value, said second power value being reached during a second predetermined maximum duration.

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

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

7. 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. 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. Method according to claim 8 characterized in that when said cooling system is activated, said method comprising a restoration 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 restoration duration or when the electronic management system is in the second configuration and no fault is detected during a second predetermined restoration duration.

10. 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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