Battery with integrated maintaining circuit, associated vehicle and method
Patent Information
- Application Number
- EP2023706630
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-02-28
- Filing Date
- 2023-02-27
- Publication Date
- 2025-01-08
AI Technical Summary
The increasing use of batteries in aircraft for hybrid kerosene-electric engines necessitates easier maintenance, particularly allowing for the safe transportation of faulty batteries, as traditional maintenance methods are time-consuming and inefficient.
Integration of a maintenance circuit within the battery that can measure parameters such as internal resistance and capacitance, allowing for controlled discharging and health assessment, including a management system with operational and failure states, and an activation device for activating the maintenance circuit via a dry contact.
Enables efficient and safe maintenance operations, including discharging batteries to a safe state, measuring capacity and internal resistance, and assessing health without external equipment, thus reducing maintenance time and ensuring compliance with regulations.
Smart Images
Figure 1.1
Abstract
Description
[0001] Battery with integrated maintenance circuit, associated vehicle and method
[0002] The present invention relates to a battery and an associated battery maintenance method.
[0003] In aviation, batteries are used for several applications, including starting engines or powering critical systems in the event of a main power failure. This means that an aircraft typically has between 1 and 4 batteries per unit.
[0004] Furthermore, for environmental reasons, it is being considered to use hybrid kerosene-electric engines. This will lead to an increase in the use of batteries and therefore the presence of additional batteries in the aircraft.
[0005] As each of these batteries undergoes maintenance operations to ensure the safety of the aircraft's flight, battery maintenance is an activity that will take up more and more time.
[0006] There is therefore a need for batteries that are easier to maintain, in particular allowing the transport of batteries in faulty mode in compliance with current regulations.
[0007] For this purpose, the description describes a battery comprising a housing, the housing defining an interior space, the battery comprising a set of internal elements, the internal elements being inserted into the interior space, the set of internal elements comprising:
[0008] - at least one electrochemical element,
[0009] - a system for managing at least one electrochemical element, and
[0010] - a maintenance circuit for the at least one electrochemical element, the maintenance circuit being capable of obtaining a measurement of a parameter relating to the state of health of the at least one electrochemical element.
[0011] According to particular embodiments, the battery has one or more of the following characteristics, taken in isolation or in all technically possible combinations:
[0012] - the management system has at least two states, an operational state and a fault state, the maintenance circuit being capable of discharging the battery to a state of charge less than or equal to a threshold value when the management system is in the fault state, the threshold value being between 10% and 50%. - the battery comprises a device for activating the maintenance circuit comprising a dry contact.
[0013] - the parameter relating to the state of health of at least one electrochemical element is the internal resistance and / or the capacity.
[0014] - the battery further comprises a contactor inserted between a pole of the at least one electrochemical element and an output terminal and the maintenance circuit comprises a unit for controlling the current delivered by the at least one electrochemical element, the current control unit being positioned between the contactor and a pole of the at least one electrochemical element.
[0015] - the current control unit comprises a regulating device, the regulating device being, for example, a transistor.
[0016] - the maintenance circuit also includes an electrical protection device for the maintenance circuit.
[0017] - the protection device is a fuse.
[0018] The description also provides a vehicle, including an aircraft, comprising a battery as described above.
[0019] The description also relates to a method of maintaining a battery comprising a housing, the housing defining an interior space, the battery comprising a set of internal elements, the internal elements being inserted into the interior space, the set of internal elements comprising:
[0020] - at least one electrochemical element,
[0021] - a system for managing at least one electrochemical element, and
[0022] - a maintenance circuit for the at least one electrochemical element, the maintenance circuit being capable of obtaining a measurement of a parameter relating to the state of health of the at least one electrochemical element, the maintenance method comprising:
[0023] - sending a command to the maintenance circuit to obtain a measurement of a parameter relating to the state of health of the at least one electrochemical element.
[0024] In this description, the expression "suitable for" means indifferently "adapted for", "adapted to" or "configured for".
[0025] Characteristics and advantages of the invention will appear on reading the description which follows, given solely by way of non-limiting example, and made with reference to the appended drawings, in which:
[0026] - Figure 1 is a schematic representation of a vehicle comprising batteries, and
[0027] - Figure 2 is a schematic representation of the elements of a battery of Figure 1. A vehicle 10 is schematically represented in Figure 1. More precisely, the vehicle 10 is an aircraft 10.
[0028] An aircraft is a means of transport capable of rising and moving at altitude, within the Earth's atmosphere.
[0029] Here, aircraft 10 is an airplane.
[0030] Alternatively, the aircraft 10 is a helicopter.
[0031] Furthermore, other types of vehicles could be considered, such as motor vehicles or railway vehicles (trains, metro or tram).
[0032] The aircraft 10 of FIG. 1 comprises two batteries 12: a first battery 14 used for starting the aircraft 10 and a second battery 16 used as emergency power.
[0033] Each of these first and second batteries 14 and 16 are similar and have the different units visible in Figure 2.
[0034] In a manner known per se, a battery 12 comprises one or more current accumulators also called electrochemical generators, cells or elements. These elements will be referred to as electrochemical elements 18 in the remainder of the description.
[0035] An electrochemical element 18 is an electricity-generating device in which chemical energy is converted into electrical energy. The chemical energy comes from electrochemically active compounds deposited on at least one face of electrodes arranged in the electrochemical element 18. The electrical energy is produced by electrochemical reactions during a discharge of the accumulator.
[0036] The state of charge of an electrochemical element 18 is often designated by the abbreviation SOC which refers to the English term “State of Charge”.
[0037] The state of charge SOC is expressed as a percentage of a maximum state of charge.
[0038] The electrodes, arranged in a container, are electrically connected to current output terminals 20 and 22 (respectively a positive output terminal 20 and a negative output terminal 22) which ensure electrical continuity between the electrodes and an electrical consumer with which the electrochemical element 18 is associated.
[0039] In order to increase the delivered electrical power, several sealed electrochemical elements 18 can be combined together to form a battery 12. Thus, a battery 12 can be divided into modules, each module being composed of one or more electrochemical elements 18 connected together in series and / or in parallel. Thus, a battery 12 can for example comprise one or more parallel branches of electrochemical elements connected in series and / or one or more parallel branches of modules connected in series. For the sake of simplification of the subject, a case with two electrochemical elements 18 in series is described in the following, knowing that the transposition to other arrangements (a single element or more than two elements) is immediate.
[0040] The two electrochemical elements 18 have a positive pole 24 and a negative pole 26.
[0041] In the example of Figure 1, the positive pole 24 is connected to the positive output terminal 20 and the negative pole 26 is connected to the negative output terminal 22.
[0042] For example, the electrochemical elements 18 are lithium-ion elements
[0043] Furthermore, the battery 12 further comprises a unit 28 for securing the battery 12 in the event of a malfunction.
[0044] The security unit 28 makes it possible to isolate the electrochemical elements 18 from the electronic components powered by the battery 12.
[0045] In the example described, the safety unit 28 comprises a fuse 30 and a contactor 32.
[0046] For example, fuse 30 is connected to positive output terminal 20 while contactor 32 is connected to negative output terminal 22.
[0047] Other implementations of the 28 security unit are of course possible.
[0048] In particular, the security unit 28 may comprise two contactors 32 instead of just one, each contactor 32 being connected to a respective output terminal 20 and 22 of the battery 12.
[0049] The battery 12 also includes other units for controlling the electrochemical elements 18.
[0050] In this example, the battery 12 comprises a management system 34 for the electrochemical elements 18, a maintenance circuit 36 for the electrochemical elements 18 and an activation device 40 for the maintenance circuit 36.
[0051] The management system 34 is a system suitable for managing the electrochemical elements 18.
[0052] Such a management system 34 makes it possible in particular to organize and control the charging and discharging of the battery 12, to balance the charging and discharging of the different electrochemical elements 18 of the battery 12 with respect to each other.
[0053] In the example described, the management system 34 has at least two states, an operational state and a failure state. As its name indicates, in the operational state, the management system 34 is able to perform all of its functions whereas, in the failure state, the management system 34 is not capable of performing at least one of its functions. In practice, the management system 34 enters the failure state when the management system 34 detects an anomaly with respect to the expected operation of the battery 12. For example, the management system 34 may consider that an excessively high current or voltage or a faulty contactor are anomalies justifying entry into the failure state.
[0054] The management system 34 comprises a set of measuring sensors 42, a balancing unit 44 and a first electronic control circuit 46.
[0055] In the present case, the set of measuring sensors 42 comprises three sensors, namely: a voltage sensor 48 suitable for measuring the voltage at the terminals of the electrochemical elements 18, a current sensor 50 suitable for measuring the current delivered by the electrochemical elements 18 and a temperature sensor 52 suitable for measuring the temperature of the electrochemical elements 18.
[0056] The sensors of the measuring sensor assembly 42 are placed between the fuse 30 and the contactor 32.
[0057] The balancing unit 44 is suitable for balancing the electrochemical elements 18.
[0058] For this, the balancing unit 44 comprises a set of balancing resistors not shown to maintain good readability of figure 2.
[0059] Each balancing resistor is associated with a respective electrochemical element 18 and has an on and off state.
[0060] In the activated state, the balancing resistor is connected to the electrochemical element 18 to discharge it, whereas in the deactivated state, the balancing resistor is not connected to the electrochemical element 18. Switching from one state to another state is, for example, achieved by switching an electronically controlled switch.
[0061] To achieve balancing of the electrochemical elements 18, the balancing resistors corresponding to the electrochemical elements 18 having the highest charge states are placed in the activated state to homogenize the charge states of all the electrochemical elements 18.
[0062] The first electronic control circuit 46 is capable of controlling the set of measuring sensors 42 and the balancing unit 44.
[0063] The first electronic control circuit 46 is also capable of controlling the electrochemical elements 18 and the security unit 28.
[0064] Depending on the applications, the first electronic control circuit 46 is also suitable for processing the measurements from the sensors. The first electronic control circuit 46 is an electronic circuit designed to manipulate and / or transform data represented by electronic or physical quantities in registers of the computer and / or memories into other similar data corresponding to physical data in the memories of registers or other types of display devices, transmission devices or storage devices.
[0065] As specific examples, the first control electronic circuit 46 includes a single-core or multi-core processor (such as a central processing unit (CPU), a graphics processing unit (GPU), a microcontroller, and a digital signal processor (DSP)), a programmable logic circuit (such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a programmable logic device (PLD), and programmable logic arrays (PLAs)), a state machine, a logic gate, and discrete hardware components.
[0066] The maintenance circuit 36 is suitable for obtaining a measurement of a parameter relating to the state of health of the electrochemical elements 18.
[0067] State of health is often referred to as SOH, which refers to the English term for "State of Health". SOH allows the aging of the battery 12 to be estimated between a new state and an end-of-life state, or more generally, between an initial state and a final state.
[0068] A health parameter is any parameter involved in the health status, such as, for example, the temperature, voltage, or current values of electrochemical elements 18.
[0069] Other examples will be given later in the description.
[0070] The maintenance circuit 36 comprises a current control unit 54, a protection device 58 and a second electronic control circuit 60.
[0071] The current control unit 54 is a unit for controlling the current delivered by the electrochemical elements 18.
[0072] The current control unit 54 in association with the second electronic control circuit 60 and the current measurement makes it possible to regulate and control the discharge current.
[0073] The current control unit 54 is interposed between the contactor 32 and the electrochemical elements 18.
[0074] More specifically, the current control unit 54 comprises a resistor 55 and a current regulating device 56.
[0075] The resistor 55 has two terminals 62 and 64, one terminal 62 being connected on the one hand to the contactor 32 and on the other hand to the negative pole 26 of the electrochemical elements 18 and the other terminal 64 being connected indirectly to the positive pole 24 of the electrochemical elements 18.
[0076] The regulating device 56 is connected on the one hand to a terminal 64 of the resistor 55 and on the other hand to the protection device 58.
[0077] The resistor 55 and the regulating device 56 are thus in series.
[0078] The regulating device 56 plays both a current regulator role and a switch role.
[0079] As a switch, the regulating device 56 has an open state and a closed state.
[0080] The regulating device 56 is, for example, a transistor, in particular an insulated gate field effect transistor. Such a transistor is more often referred to as a MOSFET transistor, the acronym MOSFET referring to the corresponding English name of “Metal Oxide Semiconductor Field Effect Transistor” literally translating as “metal-oxide-semiconductor structure field effect transistor”.
[0081] In such a case, the regulating device 56 performs the role of regulator by operating in its linear regime.
[0082] To improve regulation, the regulation device 56 may comprise more than one transistor, for example two transistors in series.
[0083] The protection device 58 is an electrical protection device for the elements of the maintenance circuit 36.
[0084] According to the example described, the protection device 58 is a fuse.
[0085] Further, in Figure 2, the protection device 58 is in series with the current control unit 54.
[0086] The assembly of the protection device 58 and the current control unit 54 thus forms a branch 66 in parallel with the electrochemical elements 18. The branch 66 extends between two ends 68 and 70, the first end 68 of the branch 66 being connected to the negative pole 26 of the electrochemical elements 18 and to the contactor 32.
[0087] The second electronic control circuit 60 is capable of implementing a set of functions. These functions are maintenance functions and correspond to steps of a maintenance method for the battery 12.
[0088] Some of these functions will be described in more detail later in the description.
[0089] From a physical point of view, the second electronic control circuit 60 can be produced in the same way as the first electronic control circuit 46. In certain advantageous embodiments, the first electronic control circuit 46 and the second electronic control circuit 60 are combined, that is to say that these electronic control circuits are produced as a single computer.
[0090] In such a case, the elements of the computer involved in carrying out the maintenance functions are part of a partition separate from the element(s) of the computer carrying out the functions of the first electronic control circuit 46, so that the maintenance functions are isolated from the functions of the first electronic control circuit 46.
[0091] The activation device 40 of the maintenance circuit 36 is capable of activating or deactivating the maintenance circuit 36.
[0092] The activation device 40 thus allows an operator to control the second electronic control circuit 60 from the outside.
[0093] The exterior is defined relative to the housing 72 which comprises the battery 12.
[0094] The housing 72 in fact delimits an interior space 74.
[0095] The electrochemical elements 18, the management system 34 of the electrochemical elements 18, the maintenance circuit 36 of the electrochemical elements 18 and the contactor 32 are elements inserted into the interior space 74. As such, they are internal elements of the battery 12.
[0096] The management system 34 and the maintenance circuit 36 are thus each an on-board circuit integrated into the battery 12.
[0097] The housing 72 is provided with the positive output terminal 20 and the negative output terminal 22.
[0098] The activation device 40 includes a dry contact 76 having ends 78 and 80 and connections 82 and 84 connected to a respective end 78 or 80 of the dry contact 76.
[0099] A dry contact 76 is an electrical contact without a potential difference between its two terminals, unlike a resistor for example.
[0100] Dry contact 76 can therefore be activated by an operator by connecting a terminal to dry contact 76.
[0101] By activating the dry contact 76, the maintenance circuit 36 is activated whereas when the dry contact 76 is not activated, the maintenance circuit 36 is deactivated.
[0102] Ends 78 and 80 are on the housing 72 of the battery 12.
[0103] The first connection 82 connects the first end 78 of the dry contact 76 to the second end 70 of the branch 66.
[0104] As explained previously, in use, the maintenance circuit 36 of FIG. 2 is capable of performing several functions which are now described. An operator can perform a maintenance operation using the maintenance circuit 36.
[0105] It is assumed here that maintenance is performed while aircraft 10 is on the ground.
[0106] The operator connects a terminal to the dry contact 76 on a connection terminal present on the housing 72, the terminal and the maintenance circuit 36 thus being connected by a wired connection.
[0107] Alternatively, the terminal and the maintenance circuit 36 may communicate via wireless communication.
[0108] The terminal is, for example, a tablet serving as a human-machine interface.
[0109] The terminal thus allows the operator to control the maintenance circuit 36 and in particular its functions.
[0110] For example, the operator asks the maintenance circuit 36 to perform a first function corresponding to ensuring a discharge function of the electrochemical elements 18.
[0111] The maintenance circuit 36 is, here, in fact capable of discharging the electrochemical elements 18 down to a charge state threshold, even if the management system 34 is in a fault state.
[0112] The state of charge threshold is less than or equal to a threshold value.
[0113] The threshold value is between 10% and 50%, preferably between 20% and 30%, or even equal to 30%.
[0114] According to a first exemplary embodiment, the maintenance circuit 36 controls the balancing unit 44 to activate all the balancing resistors and thus discharge the electrochemical elements 18.
[0115] The maintenance circuit 36 stops the activation of the balancing resistors as soon as the state of charge is less than or equal to the desired state of charge threshold.
[0116] According to a second exemplary embodiment, the second electronic control circuit 60 controls the state of the regulation device 56. The second electronic control circuit 60 activates the regulation device 56 to discharge the electrochemical elements 18 and opens it when the electrochemical elements 18 have a state of charge less than or equal to the desired state of charge threshold.
[0117] In this exemplary embodiment, the maintenance circuit 36 is capable of determining the value of the state of charge on the basis of the measurements from the set of measurement sensors 42.
[0118] As an example of a second function, the maintenance circuit 36 makes it possible to measure the capacity of the electrochemical elements 18. For this, the maintenance circuit 36 ensures that the electrochemical elements 18 are balanced and charged to a chosen state of charge.
[0119] Maintenance circuit 36 places contactor 32 in an open state.
[0120] Furthermore, the temperature sensor 52 measures the temperature at this full charge state.
[0121] The second electronic control circuit 60 then controls the regulation device 56 to allow the desired current to pass.
[0122] The electrochemical elements 18 then discharge to their minimum voltage.
[0123] During discharge, the current sensor 50 measures the value of the current delivered by the electrochemical elements 18.
[0124] By activating a time counter, the second electronic control circuit 60 deduces a measurement of the capacity from the current values measured over time.
[0125] The second electronic control circuit 60 then compares the capacitance thus measured with a reference capacitance value.
[0126] The reference capacitance value is obtained using the measured temperature.
[0127] This comparison makes it possible to determine the presence of a gap between the capacity of the battery 12 and the expected capacity for it.
[0128] The result of the comparison is displayed on the operator terminal and recorded in a battery memory 12 forming part of one of the electronic control circuits.
[0129] For example, a simple message such as "normal behavior" or "malfunction" is sent.
[0130] Alternatively, the second electronic control circuit 60 determines the state of health SOH from the ratio of the measured capacity to the capacity of the battery 12 in the new or initial state under the same measurement conditions (in particular under the same temperature conditions).
[0131] In fact, capacity decreases with aging, reflecting a loss of available energy. In such a case, the term SOH state of health related to battery capacity 12 is often used or its abbreviation SOHC which refers to the corresponding English term "State of Health related to battery Capacity".
[0132] In such a case, the SOHC parameter is displayed on the terminal and stored in the aforementioned memory.
[0133] As an example of a third function, the maintenance circuit 36 makes it possible to measure the internal resistance of the electrochemical elements 18.
[0134] Similar to the case of the second function, the maintenance circuit 36 imposes a complete discharge on the electrochemical elements 18. During the discharge, the current sensor 50 measures the value of the current delivered by the electrochemical elements 18 and the voltage sensor 48 measures the value of the voltage at the terminals of the electrochemical elements 18.
[0135] The second electronic control circuit 60 deduces from the measured values the value of the internal resistance of the electrochemical elements 18, this being the ratio between the voltage and the current.
[0136] The second electronic control circuit 60 then compares the internal resistance thus measured with a reference internal resistance value.
[0137] The internal resistance value is obtained using the measured temperature.
[0138] This comparison is used to determine whether the internal resistance matches the internal resistance.
[0139] The result of the comparison is displayed on the operator terminal and recorded in a battery memory 12 forming part of one of the electronic control circuits.
[0140] For example, a simple message such as "normal behavior" or "malfunction" is sent.
[0141] Alternatively, the second electronic control circuit 60 determines the state of health SOH by calculating the ratio of the internal resistance thus measured by measuring the voltage and current to the internal resistance of the battery 12 in the new or initial state under the same measurement conditions (in particular under the same temperature conditions).
[0142] In fact, the internal resistance increases with the aging of the battery 12, reflecting a loss of power. In such a case, the expression SOH state of health related to the internal resistance of the battery 12 is often used or its abbreviation SOHR which refers to the corresponding English term "State of Health related to battery Resistance".
[0143] In such a case, the SOHR parameter is displayed on the terminal and stored in the aforementioned memory.
[0144] Of course, many other functions are possible and the above-mentioned functions can be combined.
[0145] For example, it could be considered to implement both the second function and the third function and display a SOH parameter dependent on the SOHC and SOHC parameters.
[0146] The maintenance circuit 36 thus makes it possible to carry out maintenance operations integrated into the battery 12. This makes it possible to avoid the use of an additional device intended to ensure these maintenance and repair operations and thus make maintenance easier. The maintenance circuit 36 thus makes it possible to ensure ground maintenance of aircraft 10 without external equipment.
[0147] In particular, the maintenance circuit 36 makes it possible to carry out checks on the correct functioning of the battery 12, by measuring the capacity or the internal resistance of the battery 12.
[0148] In particular, the maintenance circuit 36 makes it possible to discharge the battery 12 even if the battery 12 is in a faulty state.
[0149] Furthermore, the maintenance circuit 36 can be activated by the operator via the activation device 40 and controlled by the terminal. This allows the maintenance circuit 36 to be activated only on the ground during the maintenance phase. The operator can activate this function via a human-machine interface.
Claims
DEMANDS 1. Battery (12) comprising a housing (72), the housing (72) defining an internal space (74), the battery (12) comprising a set of internal elements, the internal elements being inserted into the internal space (74), the set of internal elements comprising: - at least one electrochemical element (18), - a management system (34) for at least one electrochemical element (18), and - a maintenance circuit (36) of at least one electrochemical element (18), the maintenance circuit (36) being suitable for obtaining a measurement of a parameter relating to the state of health of at least one electrochemical element (18).
2. Battery according to claim 1, wherein the management system (34) has at least two states, an operational state and a failure state, the maintenance circuit (36) being suitable for discharging the battery (12) to a state of charge less than or equal to a threshold value when the management system (34) is in the failure state, the threshold value being between 10% and 50%.
3. Battery according to claim 1 or 2, wherein the battery 12 includes an activation device (40) for the maintenance circuit (36) comprising a dry contact (76).
4. Battery according to any one of claims 1 to 3, wherein the parameter relating to the health status of at least one electrochemical element (18) is the internal resistance and / or the capacity.
5. Battery according to any one of claims 1 to 4, wherein the battery (12) further comprises a contactor (32) interposed between a pole (24, 26) of at least one electrochemical element (18) and an output terminal (20, 22) and the maintenance circuit (36) comprises a current control unit (54) delivered by at least one electrochemical element (18), the current control unit (54) being positioned between the contactor (32) and a pole (24, 26) of at least one electrochemical element (18).
6. Battery according to claim 5, wherein the current control unit (54) comprises a regulating device (56), the regulating device (56) being, for example, a transistor.
7. Battery according to any one of claims 1 to 6, wherein the maintenance circuit (36) also includes an electrical protection device (58) for the maintenance circuit (36).
8. Battery according to claim 7, wherein the protection device (58) is a fuse.
9. Vehicle (10), in particular an aircraft (10), comprising a battery (12) according to any one of claims 1 to 8.
10. Method for maintaining a battery (12) comprising a housing (72), the housing (72) defining an internal space (74), the battery (12) comprising a set of internal elements, the internal elements being inserted into the internal space (74), the set of internal elements comprising: - at least one electrochemical element (18), - a management system (34) for at least one electrochemical element (18), and - a maintenance circuit (36) for at least one electrochemical element (18), the maintenance circuit (36) being suitable for obtaining a measurement of a parameter relating to the state of health of at least one electrochemical element (18), the maintenance process comprising: - sending a command to the maintenance circuit (36) to obtain a measurement of a parameter relating to the state of health of at least one electrochemical element (18).