Battery with increased robustness, configurable by switching cells

Abstract

The present invention relates to a battery (10) comprising a branch (B) and a plurality of capacity units (12a-12b) interposed in series in the branch, each capacity unit comprising a main path (16p) and an auxiliary path (16s) mounted in parallel, at least one cell (14) interposed in the main path, a first switch (24p) interposed in the main path and a second switch (24s) interposed in the auxiliary path; the battery comprises, for each capacity unit (12a-12b), a circuit board (26a-26b) for selectively controlling opening and closure of each of the switches (24p, 24s), at least one of which is powered, so as to achieve redundancy, by sampling current (ia, ib) from said at least one cell (14) of at least two capacity units (12a, 12b), one of the currents (ia) being converted by a DC / DC converter (44) in order to make it compatible with the other (ib).

Description

[0001] BATTERY WITH INCREASED ROBUSTNESS, CONFIGURABLE BY SWITCHING CELLS

[0002] DESCRIPTION

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] The present invention relates to the general field of accumulators, and more specifically to a battery particularly suitable for equipping an electric propulsion vehicle.

[0005] TECHNICAL BACKGROUND

[0006] In the context of the energy transition, the current trend is to gradually replace internal combustion engine vehicles with vehicles powered partially or totally by an electric motor.

[0007] Most manufacturers have opted to use batteries to store and release the electricity needed to power the electric motor. A battery is a storage device that converts chemical energy into electrical energy to power the electric motor during its discharge phase, which in turn converts the electrical energy into mechanical work. Conversely, the battery converts electrical energy back into chemical energy during its recharge phase.

[0008] According to a conventional architecture as illustrated in Figure 1, an electric vehicle battery 1 is electrically connected to the electric motor 2, which drives the wheels 3 in rotation in response to the electrical energy supplied by the battery 1. This battery 1 is composed of several elementary units 4, called "cells," each consisting of a cathode, an anode, a separator, and an electrolyte. They are primarily characterized by their elementary voltage, typically from 1V to 4V depending on the electrochemistry used.

[0009] Since these cells 4 are of low power, on the order of plus or minus 1 Watt, they are commonly connected in series and / or in parallel in a static configuration meeting the required performance specifications of the motor 2. In this example, the cells 4 are installed in series of four forming sets called modules 5. These modules 5 are then connected in a network (series-parallel) in order to obtain the desired voltages / currents.

[0010] In practice, this involves forming the modules 5 by connecting cells 4 with rigorously equivalent parameters in series, so as to tend towards a loading / unloading rate of these cells at the same rate. This particularity stems from the fact that a variation in the load of the cells within the module quickly leads to cascading degradation, and then to failure.

[0011] Indeed, assuming that one of the cells in module 5 discharges completely before the others when battery 1 is discharged to power the electric motor 2, the current flowing through it will drop to zero, and battery 1 will appear completely discharged. If battery 1 is recharged, the cells will then charge until the healthy cells in module 3 reach their maximum charge, without allowing the completely discharged cell to fully charge, given that the healthy cells initially start with a non-zero charge. As can be understood, the completely discharged cell will then increase the battery's charge to a level below its maximum capacity.

[0012] Even though the cells are initially classified to form batches of cells that can be combined into modules of 5, there remains some dispersion in elementary voltage, on the order of plus or minus 1%, due in particular to the fact that they are not all manufactured according to the same industrial process.

[0013] This dispersion will only increase naturally over time due to the non-homogeneous aging of cells as they cycle through charge / discharge, until it reaches an order of magnitude of plus or minus 5%.

[0014] To solve this problem, manufacturers have implemented different technological solutions for cell balancing, including so-called passive balancing, and so-called active balancing.

[0015] Referring to Figure 2, "passive balancing" involves discharging cells that are more charged than others in a module 5 in isolation, thereby eliminating the voltage difference. This technique typically consists of integrating a circuit 6 for each cell 2, connected to its terminal, which includes a switch and a resistor of approximately 20Ω. Closing the circuit 6 with the switch thus induces the discharge of the cell in question.

[0016] In the example in Figure 2, we consider a module 5 comprising three cells, CELL 1, CELL 2, and CELL 3, whose charge levels are represented by bars. Since CELL 2 is less charged than CELL 1 and CELL 3 in this example, the passive balancing principle involves discharging CELL 1 and CELL 3 to align their charge levels with those of CELL 2.

[0017] Referring to Figure 3, "acting balancing" involves balancing the charge levels of the cells in a module by recharging a low-charge cell with energy extracted from higher-charge cells. Based on the three-cell arrangement CELL 1, CELL 2, and CELL 3 in Figure 2, Figure 3 illustrates the recharging dynamics of CELL 2 as it draws energy from the storage of CELL 1. CELL 2 charges simultaneously with the discharge of CELL 1, with each cell moving towards the charge level of CELL 3.

[0018] These various technologies, while effective, involve lowering the charge level of the cells to smooth them towards an average state. A portion of the energy stored in the cells is thus used for purposes other than powering motor 2. This leads to the need to find a solution that adapts to the imbalance in the cells without reducing their energy output.

[0019] The ongoing search for solutions has revealed the value of integrating switches based on a "power balancing" logic. This logic aims to precisely select which cells or groups of cells to use when needed by adjusting the activation of these switches. As understood, such an architecture allows for regulating the charge level of the cells by discriminating, during battery charging or discharging, which cells to use and which to isolate.

[0020] However, using such switches along the current line adds complexity to the battery due to its partitioning, which is a source of failure. Following the logic of power balancing, the aim of the invention is to propose a robust battery architecture to justify its integration into a vehicle.

[0021] DESCRIPTION OF THE INVENTION

[0022] To this end, the invention relates to a configurable battery for powering an electric vehicle motor, this battery comprising:

[0023] - a branch defined between an upper and a lower battery terminal, the lower terminal being defined as grounded; and

[0024] - a plurality of capacity units interposed in series, each between two connecting nodes along the branch, each capacity unit comprising:

[0025] -- a two-way circuit with parallel paths between the two nodes, consisting of a main path and an auxiliary path,

[0026] -- at least one cell interposed in the main pathway;

[0027] -- a set of two switches comprising a first switch interposed in the main track and a second switch interposed in the auxiliary track; the battery further comprising, for each unit of capacity, an electronic board for selectively controlling the opening and closing of each of the switches; in which a first electronic board is powered according to a redundancy logic by drawing current from said at least one cell of at least two units of capacity by means of a circuit comprising:

[0028] - a first routing loop of a first direct current which is connected on either side of said at least one cell of a first unit capacity; and

[0029] - a second routing loop of a second direct current which is connected on either side of said at least one cell of a second capacity unit; and

[0030] - an electronic decoupling system, interposed between the first and second loops, which prioritizes the flow of currents into the input of the first electronic board; the second circuit further includes a DC / DC converter enabling: - the transfer of the voltage of the second current to the ground potential of the first capacitor unit, upstream of the electronic board, in order to make the sharing of the first and second currents compatible for powering the electronic board; and

[0031] - to restore, downstream of the electronic board, the second current to the ground potential of the second capacitance unit from which it is drawn.

[0032] The invention also relates to a battery defined as follows, in which the first capacity unit that powers the first electronic board corresponds to the capacity unit whose switches are controlled by this electronic board.

[0033] The invention also relates to a battery as defined, in which each electronic card is powered according to the redundancy logic by drawing current from said at least one cell of at least two capacity units.

[0034] The invention also relates to a battery defined as follows, in which, for each electronic board, the first capacity unit that powers it corresponds to the capacity unit whose switches are controlled by this electronic board.

[0035] The invention also relates to a battery defined as follows, in which a second electronic board is powered, according to a redundancy logic by current sampling, by the same capacity units as those powering the first electronic board by means of a circuit comprising:

[0036] - a first routing loop of a first current which is connected on either side of said at least one cell of the second capacity unit; and

[0037] - a second routing loop for a second current which is connected on either side of said at least one cell of the first capacity unit; and

[0038] - an electronic decoupling system, interposed between the first and second loops, which prioritizes the flow of currents into the second electronic board; the second circuit also includes a DC / DC converter enabling:

[0039] - to transfer the voltage of the second current to the ground potential of the second capacitor unit, upstream of the second electronic board, in order to make the sharing of the first and second currents compatible for powering this electronic board; and

[0040] - to restore, downstream of the second electronic board, the second current to the ground potential of the first capacitance unit from which it is drawn.

[0041] The invention also relates to a battery thus defined, in which the first and second capacity units are juxtaposed along the branch.

[0042] The invention also relates to a battery as defined above, in which the electronic decoupling system comprises at least one diode module.

[0043] The invention also relates to a battery as defined above, comprising at least one assembly which includes:

[0044] - a bypass circuit associated with a capacity unit or associated with a series of several capacity units placed side by side along the branch, this bypass circuit comprising an electrical path along which a switch is interposed, and

[0045] - an electronic control board for the bypass circuit switch; in which the electrical path of said at least one bypass circuit extends between two ends which are connected to the nodes of the associated capacity unit or to the nodes which bound the series of several associated capacity units.

[0046] The invention also relates to a battery defined as follows, in which the bypass circuit is powered by an independent current source:

[0047] - at least one cell of the associated capacity unit and the power supply of the electronic control board for the switches of that associated capacity unit; or

[0048] - cells of the series of associated capacity units and power supplies for the electronic control boards of the switches of these associated capacity units. The invention also relates to a vehicle propelled partially or totally by an electric motor and comprising a battery thus defined for powering the electric motor.

[0049] BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for an understanding of which reference should be made to the attached drawings in which:

[0051] - [Fig.1], already described, is a diagram of the installation of a battery in a vehicle equipped with an electric motor that generates a rotational torque on the wheels;

[0052] - [Fig.2], already described, is a representation of a load balancing of cells installed in series following a passive logic, called "passive balancing";

[0053] - [Fig.3], already described, is a representation of a load balancing of cells installed in series following an active logic, called "active balancing";

[0054] - [Fig.4] is a schematic and partial view of a battery according to the invention, comprising a branch along which capacity units are mounted in series, each unit comprising a main circuitry path along which several cells are mounted in series and an auxiliary circuitry path mounted in parallel with the main path; a set of two switches, one of which is interposed in the main path and the other is interposed in the auxiliary path;

[0055] - [Fig.5] is a schematic view that illustrates the control of the switches of the capacity units by electronic boards in a battery according to the invention;

[0056] - [Fig.6] is an illustrative representation of a problem of measuring voltage across the terminals of cells connected in series;

[0057] - [Fig.7] is a partial branch view which illustrates a circuitry for measuring capacitance unit cells according to a first particular aspect of the invention;

[0058] - [Fig.8] illustrates a redundancy of power supply of electronic boards for controlling the switches of the capacity units according to a second particular aspect of the invention;

[0059] - [Fig.9] illustrates a variant of the arrangement comprising voltage limiters according to a third aspect of the invention;

[0060] - [Fig.10] illustrates another variant of the arrangement comprising voltage limiters according to the third aspect of the invention;

[0061] - [Fig.11] illustrates an example of the implementation of a countermeasure circuit according to a fourth particular aspect of the invention;

[0062] - [Fig.12] illustrates another example of the realization of a countermeasures circuit according to the fourth particular aspect of the invention.

[0063] DETAILED DESCRIPTION OF THE INVENTION

[0064] The idea behind the invention is to offer a battery architecture following a "power balancing" logic, allowing the user to decide precisely when needed whether or not to use a cell.

[0065] With reference to Figure 4, a battery 10 according to the invention comprises a branch B mounted between an upper terminal Ts and a lower terminal Ti which is connected to ground Gnd. This branch B is provided with capacity units, collectively designated as 12, arranged in series and each comprising one or more cells 14 which can be considered as elementary batteries.

[0066] In this example, branch B is equipped with four capacity units, referenced 12a, 12b, 12c and 12d, each comprising four cells 14 mounted in series.

[0067] It is understood that the invention is not strictly limited to the example in Figure 4. A different number of capacity units 12 and a different number of cells 14 per capacity unit 12 may be used, in particular a single cell 14. In practice, the number of capacity units 12 and constituent cells 14 is determined according to the cost-energy requirements balance for a given application.

[0068] Also, the battery 10 can very well include several branches B mounted in parallel between the upper and lower terminals Ts, Ti; a single branch B equipped with one or more capacity units 12, or several branches of which at least one is equipped with a capacity unit 12.

[0069] In detail, each capacity unit 12 comprises a two-way parallel circuit 16p, 16s, connected at their ends to each other by two nodes 20, 22, including a main 16p channel and an auxiliary 16s bypass channel. Node 22 corresponds to the node in the batch that is closer to the lower terminal than node 20.

[0070] The cells 14 of each capacitance unit 12 are interposed in series within the main channel 16p, alternating their polarity, that is, by connecting the positive terminal of one to the negative terminal of the one directly adjacent to it. In this way, the voltages measured across the cells 14, also called electromotive forces, are added along the main channel 16p in the expression for the voltage measured between nodes 20, 22. In the example in Figure 4, this voltage measured between the two nodes 20, 22 of a capacitance unit 12 is denoted V followed by the reference "a", "b", "c", "d" indicating the position of the capacitance unit 12 along branch B. For example, the voltage associated with unit 12a is denoted Va, while the voltage associated with unit 12d is denoted Vd.

[0071] These main and auxiliary channels 16p, 16s are each further equipped with a controlled switch, respectively designated 24p, 24s. Transistors are advantageously used as switches 24p, 24s to electrically control their conducting or blocking state of current, but the invention is not limited to this feature.

[0072] The invention aims to modulate the opening and closing of the switches of each of the capacity units 12 in such a way as to:

[0073] - to stress their cells 14 by charging / discharging the battery 10 by forcing the current to flow along the main channel 16p by closing the switch 24p of the main channel 16p and opening the switch 24s of the auxiliary channel 16s; and additionally

[0074] - isolate their cells 14 from the charging / discharging phenomenon of the battery 10 by forcing the routing of the current along the auxiliary channel 16s via the opening of the switch 24p of the main channel 16p and the closing of the switch 24s of the auxiliary channel 16s.

[0075] Referring to Figure 5, the battery 10 includes electronic boards 26 for managing the capacity units 12. Advantageously, the battery has as many electronic boards 26 as there are capacity units 12. In the example shown in Figure 5, there are four electronic boards 26a-26d, each associated with a separate capacity unit 12a-12d. These electronic boards 26a-26d each include at least one control unit 27a-27d designed to control the opening and closing of the switches 24p, 24s of the associated capacity unit 12. As shown schematically by dashed arrows, the control units 27a-27d control the switches 24p, 24s by transmitting to them a respective setpoint Cp, Cs.

[0076] In practice, the actuation of the 24p, 24s switches on the main and 16p, 16s auxiliary tracks follows an alternating dynamic: when one is open, the other is closed. This alternating open / closed state of the 24p, 24s switches ensures an uninterrupted current flow under normal operating conditions by guaranteeing that a flow path is always available.

[0077] With this architecture, it is thus possible to activate or not activate the cell(s) 14 of each capacity unit 12. In practice, this amounts to adding or not the voltage generated on either side of the cells 14 of each capacity unit 12, namely the potential difference between nodes 20 and 22, in the expression of the general voltage Vt of the battery 10 measured between the lower terminal Ti and the upper terminal Ts.

[0078] Within the framework of the invention, it is proposed to instrument each capacitance unit 12a-12d with a measurement circuitry 28a-28d ensuring the measurement of certain characteristic parameters of the cell state. This measurement circuitry 28a-28d is an integral part of the electronic boards 26a-26d and includes, for example, voltage measurement sensors across each cell and temperature sensors for each cell.

[0079] Additionally, the electronic boards 26a-26d are equipped with a diagnostic unit 29a-29d, similar to a microcontroller-type computer. This diagnostic unit 29a-29d analyzes the measurements acquired by the measuring circuitry 28a-28d, for example by comparing the potential difference measured at each cell, and communicates its analysis results to the control unit 27a-27d, which can then decide on the preferred current routing by activating the switches.

[0080] Through voltage measurements and analyses, a control unit 27a-27d can, in particular, prevent any observed imbalance between the cells 14 of the associated capacitor unit 12 from manifesting by separating them. In the example of Figure 5, the set of cells 14 of the capacitor units 12a and 12c are shown with different charge states, resulting in a voltage imbalance. They are therefore separated by preventing current from flowing along the main channels 16p of the capacitor units 12a and 12c.

[0081] Similarly, if a temperature measurement sensor indicates that a cell 14 of the corresponding capacity unit 12 is overheating, it may be considered to control the opening of the switch 24p of the main channel 16p and the closing of the switch 24s of the auxiliary channel 16s for safety purposes.

[0082] It should be noted that the management of the battery 10 according to the invention is not limited to a particular protocol, such as isolating the cells 14 of a capacity unit 12 on the sole basis of the identification of a voltage irregularity or a temperature anomaly.

[0083] For example, the battery architecture according to the invention, due to its modular nature, is particularly well-suited for use in an electric vehicle to power its electric motor. Indeed, an electric vehicle motor has a variable input voltage requirement, which depends in particular on the mechanical power to be delivered to the wheels to satisfy a driver demand (pedal pressure). The battery 10 according to the invention makes it possible to directly supply an appropriate voltage Vt and current It in real time to the electric motor, ensuring operation at nominal speed at a given operating point, by activating the cells 14 as needed through the actuation of the switches 24p, 24s of the capacity units 12.

[0084] The battery 10 according to the invention thus makes it possible to do without the use of voltage converters which are classically connected between the electric motor and a conventional type battery to align the output voltage of the battery with the motor requirements.

[0085] Following a reverse logic, the battery 10 can be controlled to deliver a constant overall voltage value Vt or to deliver any optimal voltage profile by controlling the capacity units 12 accordingly. The battery structure 10 thus described based on Figures 4 and 5 provides genuine configuration flexibility, which is of particular interest for its integration into a vehicle.

[0086] However, integrating the 24p, 24s switches, advantageously in the form of transistors, adds a layer of complexity. Solutions according to the invention will be described below that allow the battery 10 to achieve a level of integrity that meets the most stringent ASIL (Automotive Safety Integrity Levels) standards, justifying its integration into a vehicle.

[0087] According to a first particular aspect of the invention, the aim is to increase the robustness of the battery 10 by refining the voltage diagnosis of the cells 14 in order to eliminate measurement errors which can lead to poor management of the switches 24p, 24s by the electronic boards 26.

[0088] Generally speaking, it is difficult to provide a direct individual voltage measurement for each cell 14 because the reference point for the measurement cannot be changed relative to ground along branch B. In other words, when a simple voltage measurement is taken, the measured voltage represents the sum of the voltages of all the cells interposed between the cell being measured and the reference ground of branch B. Referring to Figure 6, which illustrates an arbitrary circuit comprising four cells connected in series, a voltage measurement of the first cell, labeled Cell 1, is possible since its end is connected to ground (Gnd), while it is only possible to measure the voltage of the other cells in relation to the preceding cells. For example, taking a voltage measurement at the cell furthest from ground, labeled Cell 4, is equivalent to measuring the voltage of all four cells (Cell 1 - Cell 4) together.

[0089] To measure the individual voltage across the terminals of each cell 14 in the case of the battery 10 according to the invention, namely the potential difference between the cathode and the anode, it is recommended to equip the measurement circuitry 28 with subtractor amplifiers 30, also called differential amplifiers, each associated with a separate cell 14.

[0090] With reference to figure 7, these amplifiers 30 are each configured with one output and two inputs, including a "+" input called non-inverting which is connected to the positive terminal of the associated cell by a first connecting wire 31p and a "-" input called inverting connected to the negative terminal of this cell by a second connecting wire 31n.

[0091] As understood, the inverting input "-" of the amplifier 30 associated with a cell 14 corresponds to the non-inverting input "+" of the amplifier 30 associated with the cell 14 directly juxtaposed below along the main channel 16p of a capacitor unit 12. In the same way, such a commonality of connection is found between the non-inverting input "+" of the amplifier 30 associated with a given cell and the inverting input "-" of the amplifier 30 associated with the cell 14 directly juxtaposed above.

[0092] Thus, for a given cell 14, the signal recorded at the inverting input "-" of the associated amplifier 30 corresponds to the existing voltage referred to ground upstream of this cell, that is to say, it corresponds to the sum of the voltages of the cells 14 which are interposed between the given cell and the ground of the battery 10. As for the signal recorded at the non-inverting input "+", it corresponds to the existing voltage directly downstream of the given cell, namely, it corresponds to the existing voltage upstream of the given cell plus the voltage specific to this cell.

[0093] At the output, amplifier 30 provides the individual voltage of its associated cell 14 by calculating the difference between the voltages measured at the two inputs. As can be understood, the use of such differential amplifiers 30 allows the voltage of each cell 14 to be isolated.

[0094] In general, differential amplifiers 30 are sized to operate over predefined input voltage ranges.

[0095] It should be noted, however, that when the cells 14 of a capacitance unit 12 are isolated by opening the switch 24p of the main channel 16p, or in the event of an unexpected disconnection of a cell 14, the differential amplifiers 30 operate outside these predefined input voltage ranges. Indeed, in such a situation of disconnection or current routing along the auxiliary channel 16s, the reference to the conventional power supply ground is lost. Consequently, the measurement circuitry 28 is no longer referenced to a multiple of the cells, and a so-called "floating" situation arises, which induces a debiasing of the measurement circuitry 28.

[0096] Such depolarization generates voltage measurement errors, resulting in an uncertain diagnosis by the diagnostic unit 29. Specifically, the diagnostic unit 29 may incorrectly identify a cell as healthy (a "false positive") or, conversely, incorrectly identify a cell as damaged (a "false negative") based on incorrect measurements. This situation can then lead the control unit 27 to direct the current inappropriately.

[0097] The example in Figure 7 illustrates the two specific cases in which a depolarization of the measuring circuitry 28 occurs: a first capacitance unit 12a has a cell disconnection marked by D, while the cells of a second capacitance unit 12b are isolated. In this example, capacitance units 12a and 12b each have four cells numbered from 1 to 4. The voltage associated with each cell 1-4 is denoted V1-V4.

[0098] To overcome such a situation, the principle is to map the activation / connection state of cells 14 to validate or reject the acquisition voltages recorded by the measurement circuitry 28.

[0099] The integration of the 24p, 24s switches within the framework of the invention has the advantage of guaranteeing current flow even if a cell 14 is disconnected, but this nevertheless makes the activation / connection state mapping delicate. Indeed, residual capacitances may remain across the terminals of isolated or disconnected cells 14, induced by the current flowing along the switches.

[0100] In order to allow evaluation of the activation / connection state of cells 14 and thus to determine the validity of the voltage acquisition measurements, it is recommended according to the invention to enrich the measurement circuitry 28 with controllable current sources which are connected to the inverting inputs "-" and non-inverting inputs "+" of the differential amplifiers 30.

[0101] For each differential amplifier 30:

[0102] - a first controllable current source 32u is connected to the connecting wire 31p provided between the non-inverting "+" input and the positive terminal of the corresponding cell 14; and

[0103] - a first controllable current source 32g is connected to the connecting wire 31n provided between the inverting "-" input and the negative terminal of cell 14.

[0104] The first controllable current source 32u, called "pull-up", allows for upward bias, namely pulling the potential of cell 14 towards the positive supply value of the battery, while the second controllable current source 32g, called "pull-down", allows for downward bias, that is to say tends to force the potential towards the reference ground Gnd of the battery 10.

[0105] With this arrangement, it becomes possible to detect and locate any failure by measuring the voltage across each cell 14 without activating the controllable current sources and then comparing it to the acquisition results obtained by selectively activating the first controllable current source 32u and the second controllable current source 32g.

[0106] In detail, this first aspect of the battery 10 according to the invention makes it possible to ensure reliable voltage monitoring of the cells 14 of each capacity unit 12 by means of:

[0107] - a first step S1) of measurement called "standard" in voltage across the terminals of each cell 14 via the differential amplifiers 30, without activating the controllable current sources 32u, 32g;

[0108] - a second measurement step S2) called "verification" in voltage across the terminals of each cell 14 via the differential amplifiers 30, by activating one or the other of the first and second controllable current sources 32u, 32g;

[0109] - a third step S3) of "verification" measurement in voltage across the terminals of each cell 14 via the differential amplifiers 30, by activating the other controllable current source 32u, 32g of that activated during the second step S2;

[0110] - a fourth step S4) of comparison of the voltage values ​​obtained in the three steps S1, S2 and S3 allowing to confirm the validity of the standard measurements or on the contrary to alert the diagnostic unit 29 that the basic measurements are erroneous so as to prevent an inappropriate actuation of the switches 24p, 24s by the control unit 27. It should be noted that the measurements carried out in the second step S2 and in the third step S3 are complementary in that the disconnection of a cell 14 can occur at the level of its positive pole as well as at the level of its negative pole.

[0111] In practice, when an anomaly is detected at a given cell 14, evidenced by voltage values ​​obtained at the three stages S1, S2, and S3 that do not coincide, it is advantageous to isolate the capacitance unit 12 to which this given cell belongs. In other words, in the event of a potential measurement anomaly detected at a capacitance unit 12 whose cells 14 are being used, it is advisable to implement a countermeasure to exclude its cells 14 by the control unit 27, ensuring a current bypass along the auxiliary channel 16s by opening the main channel switch 24p 16p.

[0112] By allowing precise control of the voltage across the cells 14, the measuring circuitry 28, according to this first aspect of the invention, enables the battery 10 to effectively regulate its capacity units 12 by disconnecting them when a fault is identified. By performing its self-diagnosis and activating switches 24p and 24s accordingly to isolate the fault, it is understood that the battery 10, according to this first aspect of the invention, both limits the frequency of failures and the associated maintenance steps. Furthermore, since the location of faults is known to the battery 10, maintenance can be facilitated and expedited by simply replacing the disconnected cell 12 with a healthy cell.

[0113] It should also be noted that this measurement circuit architecture 28 conveniently allows for an assessment of the connection status of the cells 14 during battery 10 startup, i.e., before the voltage Vt is established. In practice, when the vehicle starts, the invention allows the controllable current sources 32u, 32g to be activated and the "verification" voltage measurements to be taken across each cell 14, as described in steps S2 and S3. Obtaining different voltage values ​​for a cell 14 indicates a cell disconnection. In such a case, the current must be routed along the auxiliary channel 16s of the corresponding capacitor unit 12.

[0114] According to a second particular aspect of the invention, the aim is to increase the operational safety of the battery 10 by limiting the risk of loss of control of the switches 24p, 24s of the capacity units 12 by the electronic boards 26.

[0115] In practice, under-powering the electronic boards 26 can lead to their malfunction and therefore to chaotic management of the switches 24p, 24s, quickly leading to the ruin of the battery 10.

[0116] In detail, such an under-supply situation can lead, in charging as well as discharging the battery 10, to current interruptions in the battery 10 by simultaneous opening of switches 24p, 24s, or lead to short circuits in cells 14 in the opposite case of simultaneous closing of switches 24p, 24s.

[0117] As understood, the integration of the 24p, 24s switches into the battery 10 requires maintaining control of the 24p, 24s switches while ensuring that the electronic boards 26 are not underpowered.

[0118] On this basis, it is recommended according to the second aspect of the invention to create a redundancy of power supply for the electronic boards 26, namely to multiply the physical sources of supply of electrical energy ensuring the operation of the measurement circuitry and the diagnostic and control units.

[0119] In this sense, it is intended that each electronic card 26 be powered by drawing from the cells 14 belonging to:

[0120] - a first unit of capacity 12, advantageously the one that is directly controlled by the electronic board in question; and

[0121] - at least one other capacity unit 12, different from the first, in which case this first capacity unit may not be able to meet the expected characteristics in powering the electronic board.

[0122] It should be noted that adopting such power supply redundancy for the electronic boards 26a-26d, by drawing on the charge of the cells 14 of different capacity units 12a-12d, requires overcoming a potential reference constraint. Since, in the case of battery 10 operation, the cells 14 can be selectively activated or isolated depending on the open / closed state of switches 24p, 24s, it follows that the potential at each point of branch B is said to be "floating." Specifically, the potentials at the points connecting the series of cells 14 of the capacity units 12 can shift from one another.

[0123] To enable a shared energy transfer from the cells 14 of different capacity units 12 of branch B to power the same electronic board 26, it is decided according to the invention to provide power supply circuits which integrate DC / DC transformers allowing the voltage of an associated capacity unit 12 to be transferred to an isolated voltage, namely to change the ground potential.

[0124] As an example, Figure 8 illustrates an arrangement in which the electronic boards 26a and 26b, which respectively drive the capacity units 12a, 12b of the battery 10, are powered by the cells 14 of these capacity units 12a, 12b.

[0125] As understood, the first electronic board 26a is powered by the cells 14 of the first capacitor unit 12a that it drives, as well as by the cells 14 of the second capacitor unit 12b directly adjacent to it. Conversely, the second electronic board 26b is powered by the cells 14 of the second capacitor unit 12b that it drives and by the cells 14 of the first capacitor unit 12a directly adjacent to it.

[0126] With regard to the power supply of the first electronic board 26a, the battery 10 has a power supply circuit comprising a first power supply sub-circuit associated with the first capacity unit 12a and a second power supply sub-circuit associated with the second capacity unit 12b.

[0127] In detail, the first power supply sub-circuit of the first 26a board is in the form of a loop comprising:

[0128] - a first input line 40a which draws the direct current directly from the so-called upper terminal Bs of the series of cells 14 of the first capacity unit 12a, denoted ia direct, to the first electronic board 26a; and

[0129] - a first output line 42a which carries this direct current ia direct output from the first electronic board 26a to the lower terminal Bi of the series of cells 14 of the first capacity unit 12a to close the current loop associated with this first capacity unit 12a.

[0130] Regarding the second power supply sub-circuit of the first 26a board, it also takes the form of a loop comprising:

[0131] - a second input line 40b which carries the current from the so-called upper terminal Bs of the series of cells 14 of the second capacity unit 12b to the first electronic board 26a; and

[0132] - a second output line 42b which carries the current from the output of the first electronic board 26a to the lower terminal Bi of the series of cells 14 of the second capacity unit 12b to close the current loop associated with this second capacity unit 12b.

[0133] Note that in order to allow the first electronic board 26a to be powered by means of the two currents ia and ib despite the floating nature of the points of branch B to which the first and second capacity units 12a, 12b belong, it is recommended to interpose a first isolated DC / DC converter 44 in the second sub-circuit.

[0134] This first 44-amp DC / DC converter is designed for both:

[0135] - transform, along the second input line 40b, the direct current, denoted ib direct, which is drawn from the upper terminal Bs of the second capacitor unit 12b, into a direct current ib dc / dc which is referred to the ground potential of the first capacitor unit 12a, denoted ref12a, upstream of the first electronic board 26a; and

[0136] - restore the direct current ib along the second output line 42b, downstream of the first electronic board 26a, by converting the direct current ib dc / dc back into direct current ib, namely into current referred to the ground potential of the second capacitance unit 12b, noted ref12b, so that it can return to this second capacitance unit 12b.

[0137] Specifically, the second input line 40b is split on either side of the DC / DC converter 44 into:

[0138] - an upstream pre-transformation portion 40b1 which carries the direct current ib, taken from the upper terminal Bs of the series of cells 14 of the second capacity unit 12b, to an input of the DC / DC converter 44 to be transformed into a DC / DC current ib compatible with sharing with the direct current ia flowing along the first sub-circuit to power the first electronic board 26a; and

[0139] - an upstream post-transformation portion 40b2 which extends from an output of the DC / DC converter 44 to the first electronic board 26a to supply it with said current ib dc / dc at the end of its transformation at the level of the DC / DC converter 44.

[0140] Similarly, the second output line 42b can be split on either side of the DC / DC converter 44 into:

[0141] - a downstream post-transformation portion 42b2 which carries the current ib dc / dc downstream of the first electronic board 26a to an input of the DC / DC converter 44;

[0142] - a downstream return portion 42b1 which connects an output of the DC / DC converter 44 to the lower terminal Bi of the series of cells 14 of the second capacitance unit 12b, to reinject the current ib which has been counterbalanced in its direct ib form into the DC / DC converter 44 from the dc / dc ib current.

[0143] As understood, the first DC / DC converter 44 equips the second power supply subcircuit to conform the current ib so that it is aligned with the ground potential of the first capacitance unit 12a, in the form ib dc / dc, and thus be eligible to supply the first electronic board 26a commonly with the direct current ia, before restoring it to its original direct ib form to return to the second capacitance unit 12b.

[0144] In addition, the power supply circuit of the first electronic board 26a is provided with two diode modules, identified by 46 and 48. These diode modules 46 and 48 each form a sharing / de-sharing interface between the first and second power supply sub-circuits at the input and output of the first electronic board 26a.

[0145] The first diode module 46 is positioned upstream of the first electronic board 26a. It has one output which is connected to the power input of the first electronic board 26a by a line labeled 49i, and two inputs, including:

[0146] - an input connected to the first input line 40a along which the direct current ia flows, and

[0147] - an input connected to the upstream post-transformation line 40b2 of the second input line 40b which carries the ib dc / dc current.

[0148] In practice, this first diode module 46 performs a power supply function, also known as electronic decoupling, which differentiates between input currents by allowing the flow of the direct current ia or the DC / DC current ib with the highest voltage, namely the current best suited to meet the minimum current required by the electronic board 26a, i.e., its nominal current. As understood, this first diode module 46 ensures a continuous power supply to the electronic board 26a with a sufficient current level by substituting the faulty direct current ia with the DC / DC current ib, and vice versa.

[0149] The second diode module 48 is located downstream of the first electronic board 26a. It has one input which is connected to the power supply output of the first electronic board 26a by a line labeled 49s, and two outputs, including:

[0150] - an output connected to the first output line 42a along which the direct current ia flows, and

[0151] - an output connected to the downstream post-transformation line 42b2 of the second output line 42b which carries the current ib dc / dc.

[0152] This second diode module 48 guarantees, in the same way as for the first diode module 46, the decoupling of the direct ia and dc / dc ib currents at the output of the first electronic board 26a.

[0153] It should also be noted that by nature, the diode modules 46 and 48 provide an anti-reflux function, namely they impose the direction of current flow, indicated by arrows in Figure 8, from the capacitance units 12a, 12b to the first electronic board 26a on the way there, and then from the first electronic board 26a to the capacitance units 12a, 12b on the return of the current.

[0154] The power supply topology of the first electronic board 26a was explained as involving a conversion of the DC current ib to match the ground potential ref12a of the current ia, thus creating a compatible power supply. The power supply of the second electronic board 26b follows the same logic, except that this time it is the current ia that undergoes conversion by a second isolated DC / DC converter, while the current ib remains unchanged. A second DC / DC converter, designated 54, is therefore recommended to transform the current ia to match the ground potential, ref12b, of the second capacitor unit 12b, making it compatible with the current ib, and then to restore the current ia to its original ground potential, namely the ground potential ref12a of the first capacitor unit 12a.

[0155] In detail, the power supply of the second electronic board 26b is provided by the battery 10 by means of a first power supply sub-circuit associated with the second capacity unit 12b and a second power supply sub-circuit associated with the first capacity unit 12a.

[0156] The first power supply sub-circuit of the second electronic board 26b is in the form of a loop comprising:

[0157] - a first input line 50b which draws the direct current, ib direct, directly taken from the upper terminal Bs of the series of cells 14 of the second capacitance unit 12b to the second electronic board 26b; and

[0158] - a first output line 52b which carries this direct current ib from the output of the second electronic board 26b to the lower terminal Bi of the series of cells 14 of the second capacitance unit 12b to close the current loop associated with this second capacitance unit 12b.

[0159] Regarding the second power supply sub-circuit of the second electronic board 26b, it also takes the form of a loop comprising:

[0160] - a second input line 50a which carries the current from the upper terminal Bs of the series of cells 14 of the first capacity unit 12a to the second electronic board 26b; and

[0161] - a second output line 52a which carries the current from the output of the second electronic board 26b to the lower terminal Bi of the series of cells 14 of the first capacitor unit 12a to close the current loop associated with this first capacitor unit 12a. To allow the second electronic board 26b to be powered by the two currents ia and ib despite the floating nature of the points in branch B, the second isolated DC / DC converter 54 is interposed in the second input and output lines 50a, 52a of the second sub-circuit. This second DC / DC converter 54 allows both:

[0162] - transform, along the second input line 50b, the direct current ia, which is drawn from the upper terminal Bs of the first capacitor unit 12a, into a direct current ia dc / dc which is referred to the ground potential ref12b of the second capacitor unit 12b, upstream of the second electronic board 26b; and

[0163] - restore the direct current ia along the second output line 52a, downstream of the second electronic board 26b, by converting the DC current ia dc / dc back into direct current ia, aligned with the ground potential ref12a of the first capacitance unit 12a, so that it can return to this first capacitance unit 12a.

[0164] In a manner analogous to the arrangement described of the second power supply subcircuit of the first electronic board 26a, the second input line 50b and the second output line 52b of the second power supply subcircuit of the second electronic board 26b can be discretized into two portions on either side of the DC / DC converter 54.

[0165] Thus, we can identify along the second line of entry 50a:

[0166] - an upstream pre-transformation portion 50a1 which carries the direct current ia, taken from the upper terminal Bs of the series of cells 14 of the first capacitance unit 12a, to an input of the DC / DC converter 54 to be transformed into a DC / DC current ia compatible with sharing with the direct current ib flowing along the first sub-circuit to power the second electronic board 26b; and

[0167] - an upstream post-transformation portion 50a2 which extends from an output of the DC / DC converter 54 to the second electronic board 26b to supply it with said current ia dc / dc obtained at the end of its transformation at the level of the DC / DC converter 54.

[0168] Similarly, the second output line 52a can be split on either side of the second DC / DC converter 54 into:

[0169] - a downstream post-transformation portion 52a2 which carries the DC / DC current ia downstream of the second electronic board 26b to an input of the DC / DC converter 54; and

[0170] - a downstream return portion 52a1 which connects an output of the DC / DC converter 54 to the lower terminal Bi of the series of cells 14 of the first capacitance unit 12b, to reinject the current ia which has been counterbalanced in its direct form ia into the DC / DC converter 54 from the current ia dc / dc.

[0171] Similarly to the power supply circuit of the first electronic board 26a, the power supply circuit of the second electronic board 26b is provided with two diode modules, identified by 56 and 58. These diode modules 56 and 58 each form a sharing / de-sharing interface between the first and second power supply sub-circuits at the input and output of the second electronic board 26b.

[0172] The first diode module 56 is located upstream of the second electronic board 26b. It has one output which is connected to the power input of the second electronic board 26b by a line labeled 59i, and two inputs, including:

[0173] - an input connected to the first input line 50b along which the direct current ib flows, and

[0174] - an input connected to the upstream post-transformation line 50a2 of the second input line 50a which carries the current ia dc / dc.

[0175] The second diode module 58 is located downstream of the second electronic board 26b. It has one input which is connected to the power supply output of the second electronic board 26b by a line labeled 59s, and two outputs, including:

[0176] - an output connected to the first output line 52b along which the direct current ib flows, and

[0177] - an output connected to the downstream post-transformation line 52a2 of the second output line 52a which carries the current ia dc / dc.

[0178] Power supply redundancy has been explained based on the example in Figure 8, in which the electronic boards 26a, 26b, which control the juxtaposed capacity units 12a, 12b of the battery 10, are powered by the cells 14 of these capacity units via DC / DC converters ensuring the compatibility of the currents ia and ib. This redundancy logic is applicable to all the electronic boards 26 of the battery 10. It should be noted, however, that the invention is not strictly limited to a particular number or condition of juxtaposition of the capacity units 12 used. Specifically, the use of isolated DC / DC converters makes it possible to power an electronic board 26 controlling a given capacity unit 12 with the cells of at least one other capacity unit 12 by transferring the voltage of the current drawn from this other capacity unit 12 to the isolated voltage that is compatible with the electronic board 26.In practice, although it is advantageously preferred for ease of connection that the electronic boards 26 each be powered by the cells 14 of the capacity unit 12 that it drives and at least one adjacent unit as in the example of Figure 8, the invention is not strictly limited to this feature. As understood, the power supply redundancy of a given electronic board 26 can be ensured by the cells 14 of two or more capacity units 12, regardless of their relative position in the battery 10, provided that isolated DC / DC converters are provided in accordance with the invention.

[0179] Finally, it should be noted that the battery 10, according to this second aspect, is not strictly limited to the use of a diode module. In practice, any electronic equipment or group of electronic equipment that allows for the prioritization of the currents supplied by the cells 14 of the capacity units 12 to power the same electronic board 26 can be used as a substitute for a diode module as illustrated.

[0180] According to a third particular aspect of the invention, the aim is to increase the reliability of battery 10 by limiting the risk of damage by overvoltage of the constituent elements of battery 10.

[0181] During the operational life of the battery 10, a cell 14 of a capacity unit 12 along branch B may unexpectedly disconnect or fail. A cell 14 disconnection may be caused, in particular, by vibrations generated when the vehicle equipped with the battery 10 is in motion, or by any other cause creating a local voltage increase. For example, a large current variation can induce overvoltages in the cells. If the capacity unit 12 with a faulty / disconnected cell is subjected to charging or discharging the battery 10—that is, when the main channel 16p switch 24p is closed and the auxiliary channel 16s switch 24s is open—a sudden voltage spike occurs between the upper terminal Ts of the battery 10 and the faulty / disconnected cell.

[0182] This voltage spike, depending on the location of the fault / disconnection along branch B, can be significantly higher than the maximum voltage that the constituent elements of battery 10, particularly cells 14, can withstand. Such an electrical overvoltage stress event can therefore lead to damage to the electronic components used to diagnose cells 14, or even to the destruction of battery 10.

[0183] In the absence of being able to predict the occurrence of a failure or disconnection of cell 14, it is recommended in this third particular aspect of the invention to prevent the appearance of the voltage peak, or at least to limit the voltage seen by the diagnostic components during the peak, by means of the use of voltage limiters 60.

[0184] According to an example of an arrangement, illustrated in Figure 9, the measuring circuitry 28 of the capacitance units 12 is equipped with voltage limiters 60, each associated with a corresponding cell 14. These voltage limiters 60 are in the form of modules, each interposed in series along the connecting wire 31p provided between the positive terminal of a cell 14 and the non-inverting "+" input of the corresponding differential amplifier 30. Each voltage limiter 60 is advantageously referenced to the potential of the lower part of the capacitance unit 12, namely referenced to node 22, which ensures a maximum voltage that must not be exceeded between the lower reference and the line of the cell to be diagnosed.

[0185] In this example, the voltage limiters 60 can be of any type, passive or active, as long as they are compatible with a series connection with the power line, such as an inductor, a semiconductor block, or a block with a biased magnetic core.

[0186] With this arrangement, any overvoltage incident along branch B, and more specifically along the main channel 16p of the capacity units 12, does not affect the measuring circuitry 28, which is protected by the voltage limiters 60 acting as barriers. It follows that the current received by the measuring circuitry 28 always remains below a maximum voltage limit to which its components can be subjected without damage.

[0187] It should be noted that the third particular aspect of the invention is not strictly limited to the arrangement in Figure 9, in which the voltage limiters are installed in series between the cells 14 and the differential amplifiers 30 of the measuring circuitry 28, along the first connecting wires 31p. Alternatively, a parallel arrangement of the voltage limiters 60 may be used.

[0188] As an example of a variant of the parallel arrangement, Figure 10 illustrates a capacity unit 12 of the battery 10 which is equipped with voltage limiters 60 in the form of Zener diodes arranged between the cells 14. In detail, each cell 14 is equipped with two voltage limiters 60 each placed in parallel at one of the terminals and connected to the ground Gnd of the battery 10.

[0189] This unique arrangement with two voltage limiters 60 connected to the terminals of cells 14 helps to counteract the occurrence of an overvoltage resulting from:

[0190] - a disconnection between a cell terminal and the main channel 16p of the capacity unit 12 in which it is interposed; or

[0191] - a disruption of the main 16p pathway caused between two cells 14;

[0192] - an intrinsic failure of cell 14.

[0193] These diodes 60, characterized by a so-called "breakdown" voltage, also known as the "Zener voltage," divert a portion of the current flowing along the main channel 16p when its voltage exceeds the breakdown voltage. As can be understood, if the input voltage, namely the voltage measured across cell 14 with which the Zener diode 60 is connected in parallel, rises above the breakdown voltage, a portion of the current flows through the diode 60 instead of along the main channel 16p.

[0194] Based on this, the Zener diodes used are designed to block any unwanted voltage rise beyond a predefined value, corresponding to a maximum voltage acceptance threshold at the terminal of the relevant cell 14. It follows that the current flowing along the main channel 16p always satisfies a maximum voltage threshold to which the battery components 10 can be subjected without degradation. They are judiciously used within the framework of the invention, taking care to limit their current and reduce their leakage in order to minimize diagnostic measurement errors.

[0195] Also, Zener 60 diodes are judiciously used in combination with resistors, not shown, to limit the intensity of the current passing through them to an admissible value, namely to a value that they can withstand.

[0196] It should be noted that the arrangement in Figure 10 is not specifically limited to the use of such Zener diodes as voltage limiters 60. In practice, any type of device that imposes a maximum voltage along the main channel 16p of the capacitance units 12, particularly across the cells 14, can be used within the meaning of the present invention. For example, Zener diodes can be replaced by so-called Transil diodes.

[0197] Finally, it should be noted that a mixed arrangement can be used within the framework of this third particular aspect of the invention to combine their respective advantages, namely an arrangement that includes both:

[0198] - voltage limiters 60 arranged in series along the connecting wires 31p linking the main channel 16p of the capacitance units 12 to the differential amplifiers 30 of the measuring circuitry 28, in accordance with the arrangement in Figure 9; and

[0199] - voltage limiters 60 arranged in parallel across the terminals of cells 14, based on the example in Figure 10.

[0200] It is particularly important to emphasize that the integration of voltage limiters 60 can also be applied in a generic battery architecture comprising a plurality of cells installed in series to provide an overall voltage that exceeds the voltage that these cells can withstand. According to a fourth particular aspect of the invention, the aim is to increase the operational reliability of the battery 10 by providing a countermeasure against a failure of the switches 24p, 24s of the capacity units 12 or a failure of the control of these switches by the associated electronic boards 26.

[0201] In a failure situation characterized by a lack of response or an inadequate response from switches 24p, 24s to a given setpoint, or even chaotic control of switches 24p, 24s by an electronic board 26, these cases can lead to severe situations:

[0202] - interruption of the current in the event of simultaneous opening of these switches, or

[0203] - short circuit of cells 14 in case of simultaneous closure of the switches.

[0204] To avoid such events severely impacting the integrity of the battery 10, it is recommended according to this fourth aspect to enrich it with bypass circuits 70, from the English "by-pass", allowing the current, in discharge or charge of the battery 10, flowing along branch B so that it does not pass through the capacity units 12.

[0205] The example in Figure 11 illustrates two capacitance units 12a, 12b, each driven by a separate electronic board 26a-26b. Each capacitance unit 12 is assigned a bypass circuit 70 in the form of an electrical channel 72 along which a switch 74 is interposed. Advantageously, and without limitation, this switch 74 is a transistor.

[0206] In detail, the electrical path 72 of each bypass circuit 70 extends between two ends which are each grafted to a node 20, 22 of the capacity unit 12 considered, so as to form an external current routing path different from the main and auxiliary paths 16p, 16s.

[0207] Each bypass circuit 70 is allocated an electronic card 76 for controlling the switch 74, which sends a control command Cb for opening or closing.

[0208] When the switch 74 of a given bypass circuit is opened, it is understood that said bypass circuit 70 is non-working, that is, it has no influence on the current flowing through the capacity unit 12. Conversely, closing the switch 74 creates a preferential path for the current to flow along the electrical path 72 of the bypass circuit 70, so that it no longer flows along the main path 16p or the auxiliary path 16s of the capacity unit 12. In other words, when the switch 74 is closed, the bypass circuit 70 ensures a current diversion between the nodes 20 and 22 that connect the capacity unit 12. In such a case, the electrical path 72 of the bypass circuit 70 becomes analogous to a portion of a battery branch 10 that is devoid of cells 14.

[0209] It should be noted that the scope of the invention is not restricted to the example in Figure 11 in which a bypass circuit 70 is allocated to each capacity unit 12. It is understood here that an arrangement may be considered in which a bypass circuit 70 provides a current diversion along several juxtaposed capacity units along branch B.

[0210] Figure 12 illustrates this particularity by associating, as a non-limiting example, two by two the capacity units 12a-12d of branch B of battery 10 with a bypass circuit 70. In this example, we distinguish an electronic board denoted 26ab which controls capacity units 12a and 12b, and an electronic board denoted 26cd which controls capacity units 12c and 12d.

[0211] According to this arrangement, the electrical path 72 of each bypass circuit 70 is connected to the so-called extremum nodes 20, 22, namely, bounding the series of juxtaposed capacity units 12, to allow the current to bypass them as needed.

[0212] A current diversion along several juxtaposed capacity units 12 by the same bypass circuit 70 is particularly preferable if these capacity units are controlled by the same electronic board 26 as illustrated in figure 7. Indeed, a switch control corruption by the electronic board 26 can generalize to all the capacity units allocated to it.

[0213] Each bypass circuit 70 is preferably controlled by a separate electronic board 76, but an arrangement of several bypass circuits 70 controlled by the same electronic board 76 does not fall outside the scope of the invention. Generally, the bypass circuits 70 are intended to ensure current rerouting as quickly as possible in the event of a detected failure. To this end, the battery 10 incorporates a communication network 80 enabling the transmission of the failure information to the electronic board 76 controlling the appropriate countermeasure bypass circuit 70.

[0214] This network 80 primarily comprises main communication channels 82 between each electronic control board 26 for a capacity unit 12 and the electronic control board 76 for the bypass circuit 70 associated with the capacity unit in question. As an illustrative example, the electronic control board labeled 26a in Figure 10, which controls the capacity unit 12a, is connected by a main communication channel 82 to its associated electronic control board 76.

[0215] In the case where a 24p, 24s switch of unit capacity 12 is the cause of the failure, for example when it does not respond satisfactorily to the control instruction Cp, Cs which is transmitted to it by its electronic card 26, the latter is able to send the information of the failure up the main communication channel 82.

[0216] Also, the network 80 includes secondary communication channels 84 ensuring dialogue between the electronic boards 26 controlling the capacity units 12 or between the electronic boards 76 controlling the bypass circuits 70. These secondary communication channels 84 allow the detection of a fault to be sent back to the appropriate electronic board 76 for countermeasures via one or more other electronic boards forming a relay point.

[0217] These secondary communication channels 84 thus ensure transmission of the fault detection even if the electronic board 26 of the faulty capacity unit 12 is unable to communicate directly with the appropriate countermeasure electronic board 76. Specifically, the electronic board 26 of the faulty capacity unit 12 sends a transmission message along all the communication channels 82, 84, so that the fault identification information has a significantly greater chance of reaching the appropriate countermeasure electronic board 76.

[0218] In practice, the primary and secondary communication channels 82 and 84 of network 80 are also subject to a risk of failure. To maintain control over information routing, these channels are configured independently of each other. Thus, if one channel is unexpectedly interrupted, the other channels can still successfully transmit the fault detection.

[0219] Therefore, it is advantageously recommended that each electronic card 26, 76 be capable of detecting faulty communication on the communication channels 82, 84 with which it cooperates by means of a "watchdog" type control mechanism. As understood, these control mechanisms, denoted 85, allow the electronic cards 26, 76 to recognize an anomaly in the routing of information on a channel and to exclude it from the information management process.

[0220] Therefore, to ensure that a failure occurring on a given capacity unit 12 or on its associated electronic board 26 does not affect the control of the bypass circuit 70 designed to counteract it, the power supply to the electronic board 76 that controls this bypass circuit 70 is intended to be independent of these components. In Figures 9 and 10, the power supply to the electronic boards 26 that control the capacity units 12 is collectively labeled AL26; while the power supply to the electronic boards 76 that control the bypass circuits 70 is labeled AL76.

[0221] For example, if the electronic board 26 controlling one or more capacity units 12 is powered (AL26) by the cells 14 of this or these capacity units, in accordance with the preferred embodiment described in the third aspect of the invention, these cells 14 are not used for the power supply (AL76) of the electronic board 76 controlling the bypass circuit 70.

[0222] Powering the electronic control boards 76 for the bypass circuits 70 with a separate power source AL76 from the battery 10 is certainly advantageous. As a non-limiting example, these electronic boards 76 could be conveniently powered by the 12V SLI battery (starting-lighting-ignition), which is standard equipment in all vehicles to ensure the proper functioning of critical systems.

[0223] Similar to the power supply for the electronic boards 26 as described in the second specific aspect of the invention, it is advantageous to multiply the power supply sources for the electronic boards 76 in the form of redundancies. Indeed, since the bypass circuits 70 each form a safety barrier against damage to the battery 10 resulting from a failure of the capacity units 12 or the electronic boards 26 that monitor them, a redundant power supply for the electronic boards 76 that control them ensures that the overall reliability requirements are met to the highest degree.

[0224] Finally, within the framework of this fourth aspect according to the invention, a second safety curtain is advantageously erected in the event of failure of a bypass circuit 70 or of its control by the associated electronic card 76.

[0225] In concrete terms, a critical situation may arise in which the bypass circuit 70, which corresponds to the first safety curtain, does not fulfill its role of diverting the current along its electrical path 72 when the capacity unit 12 assigned to it is faulty.

[0226] This second safety curtain consists of blocking in a controlled manner the passage of current along branch B whose capacity unit 12 is faulty, advantageously by means of a fuse 86 which can receive a cut-off instruction from all electronic boards by means of an independent safety wire 88.

[0227] The management of the capacity units 12 has been defined so far on the basis of temperature and voltage measurements of the cells 14 by the electronic boards 26, while the implementation of the means of countermeasures has been explained as being based on the assessment of compliance with the opening / closing instructions of the switches 24p, 24s and 74 conditioning the routing of the current.

[0228] It should be noted that the transistors used to make up the 24p, 24s, and 74 switches are semiconductor components with a specific impedance and voltage and temperature acceptance ranges. In practice, a current that may be acceptable for the 14 cells is not necessarily acceptable for a given transistor, which can lead to excessive heating and damage.

[0229] These limitations also need to be taken into account in the management of the capacity units 12 and the means of countermeasures, the electronic boards 26, 76, and more specifically their measurement circuitry, are enriched with temperature and voltage measurement sensors at the terminals of the switches 24p, 24s and 74 which they supervise.

[0230] Based on this incrementation of temperature sensors and voltage measurement at the terminals of transistors 24p, 24s, 74, it notably made it possible, according to a fifth particular aspect of the invention, to strengthen the control of the battery 10, and consequently of the electrical behavior of the vehicle equipped with it.

[0231] In general, the integration of transistors 24p, 24s, 74 in battery 10 is likely to pollute the voltage measurements of cells 14, in particular because their impedance adds to those of the cells.

[0232] In practice, when a voltage measurement is taken across the terminals of a cell 14, the voltage value collected is also a function of the open or closed state of the transistors.

[0233] Similarly, the presence of transistors 24p, 24s, and 74 in battery 10 is also likely to skew the temperature measurements of cells 14. Since even the slightest current flowing through a transistor causes it to heat up, this results in a rise in the ambient temperature around it. Consequently, the temperature measured at a given cell 14, depending on its relative position with a transistor, could be artificially inflated. This could lead to an undesirable situation where the cells 14 of a capacitance unit 12 are incorrectly isolated due to an excessively high operating temperature reading.

[0234] With knowledge of the temperature and voltage across the transistors, as well as their position in the battery, it becomes possible to refine the voltage and temperature measurements of the cells 14, thus avoiding such a situation. Within the framework of this fifth specific aspect, it is therefore proposed that the diagnostic units 29 of the electronic boards 26 controlling the capacity units 12 take into account the temperature and voltage measured at the transistors when assessing the parameters of the cells 14. Specifically, this involves formulating a phenomenological model for assessing the performance of the cells 14, which provides expected temperature and voltage values ​​across each cell 14 of the capacity units 12, depending on whether the switches are open or closed.

[0235] This model can be generated as follows:

[0236] - S1) collect satisfactory temperature and voltage ranges across the terminals of each cell 14 considered in isolation, according to manufacturer standards;

[0237] - S2) quantify the influence of the opening or closing of the transistors on the acquisition values ​​in temperature and voltage across each cell 14 on the basis of temperature and voltage measurements across the transistors forming switches 24p, 24s of the capacitance units 12, and also of the bypass circuit 60 within the framework of the fourth aspect;

[0238] - S3) define satisfactory inherent temperature and voltage ranges across the terminals of each cell 14 of the battery 10.

[0239] It should also be noted that the data gathered on the voltage and temperature of transistors 24p, 24s, and 74 allows for the construction of a more precise predictive model of the expected performance of battery 10, based on the conducting or blocking state of these transistors 24p, 24s, and 74, than a model built on the basis of cell voltage and temperature. This model can serve as the basis for real-time control of battery 10 according to the vehicle's needs.

[0240] This knowledge, correlated with a measurement of the intensity (It) of the current passing through branch B, also makes it possible to model the battery 10 in real time and in particular to enrich the behavioral model of the battery 10 on the basis of the series impedance of the cells 14 which varies according to the conducting or blocking state of the transistors 24p, 24s, 74. Such a model allows a precise evaluation of the capacity of the battery 10 to supply or receive current as a function of the activation state of the transistors 24p, 24s, 74.

[0241] This model can also serve as an indicator of battery 10 malfunctions. In practice, if battery 10 performs below, or at least differently than, the expected performance for a given configuration, this indicates a malfunction. "Configuration" refers to the resultant of all the opening / closing actions of switches 24p, 24s, and 74, which determines whether or not the cells 14 are activated, as expressed in the current (It) and voltage (Vt) values ​​carried along branch B of battery 10.

[0242] The various specific aspects of battery 10 according to the invention have been described in isolation from one another, but it should be noted that the invention obviously allows them to be combined partially, or totally, to move towards the most optimized architecture.

Claims

DEMANDS 1. Configurable battery (10) for powering an electric vehicle motor comprising: - a branch (B) defined between an upper terminal (Ts) and a lower terminal (Ti) of the battery, the lower terminal (Ti) being defined as ground; and - a plurality of capacity units (12a-12d) interposed in series, each between two connecting nodes (20, 22) along the branch (B), each capacity unit (12a-12d) comprising: -- a two-way circuit (16p, 16s) mounted in parallel between the two nodes (20, 22), of which a main channel (16p) and an auxiliary channel (16s), -- at least one cell (14) interposed in the main channel (16p); -- a set of two switches (24p, 24s) comprising a first switch (24p) interposed in the main track (16p) and a second switch (24s) interposed in the auxiliary track (16s); the battery (10) further comprising, for each capacity unit (12a-12d), an electronic board (26a-26d) for selectively controlling the opening and closing of each of the switches (24p, 24s); characterized in that a first electronic board (26a) is powered according to a redundancy logic by drawing current from said at least one cell (14) of at least two capacity units (12a, 12b) by means of a circuit comprising: - a first loop (40a, 42a) for routing a first current (ia) which is connected on either side of said loop to at least one cell (14) of a first capacity unit (12a); and - a second loop (40b, 42b) for routing a second current (ib) which is connected on either side of said loop to at least one cell (14) of a second capacity unit (12b); and - an electronic decoupling system (46, 48), interposed between the first loop (40a, 42a) and the second loop (40b, 42b), which prioritizes the flow of currents (ia, ib) into the input of the first electronic board (26a) forming a second sub-circuit, said second sub-circuit further comprising a DC / DC converter (44) enabling: - to transfer the voltage of the second current (ib) to the ground potential (ref12a) of the first capacity unit (12a), upstream of the electronic board (26a), in order to make the sharing of the first and second currents (ia; ib) compatible for powering the electronic board (26a); and - to restore, downstream of the electronic board (26a), the second current (ib) to the ground potential (ref12b) of the second capacitance unit (12b) from which it is taken.

2. Battery (10) according to claim 1, wherein the first capacity unit (12a) which powers the first electronic board (26a) corresponds to the capacity unit whose switches (24p, 24s) are controlled by this electronic board (26a-26d).

3. Battery (10) according to claim 1 or 2, in which each electronic card (26a-26d) is powered according to the redundancy logic by drawing current from said at least one cell (14) of at least two capacity units (12a, 12b).

4. Battery (10) according to claim 3, in which, for each electronic card (26a-26d), the first capacity unit (12a) which powers it corresponds to the capacity unit whose switches (24p, 24s) are controlled by this electronic card (26a-26d).

5. Battery (10) according to any one of the preceding claims, wherein a second electronic board (26b) is powered, according to a current-sucking redundancy logic, by the same capacity units (12a, 12b) as those powering the first electronic board (26a) by means of a circuit comprising: - a first loop (50b, 52b) for routing a first current (ib) which is connected on either side of said loop to at least one cell (14) of the second capacity unit (12b); and - a second loop (50a, 52a) for routing a second current (ia) which is connected on either side of said loop to at least one cell (14) of the first capacity unit (12a); and - an electronic decoupling system (56, 58), interposed between the first loop (50b, 52b) and second loop (50a, 52a), which prioritizes the flow of currents (ia, ib) into the input of the second electronic board (26b) forming the second sub-circuit, said second sub-circuit further comprising a DC / DC converter (54) enabling: - to transfer the voltage of the second current (ia) to the ground potential (ref12b) of the second capacitor unit (12b), upstream of the second electronic board (26b), in order to make the sharing of the first and second currents (ia; ib) compatible for powering this electronic board (26b); and - to restore, downstream of the second electronic card (26b), the second current (ia) to the ground potential (ref12a) of the first capacitance unit (12a) from which it is taken.

6. Battery (10) according to claim 5, wherein the first and second capacity units (12a, 12b) are juxtaposed along the branch (B).

7. Battery (10) according to any one of the preceding claims, wherein the electronic decoupling system comprises at least one diode module (46, 48; 56, 58).

8. Battery (10) according to any one of the preceding claims, comprising at least one assembly which includes: - a bypass circuit (70) associated with a capacity unit (12a-12d) or associated with a series of several capacity units (12a-12d) placed side by side along the branch (B), this bypass circuit (70) comprising an electrical path (72) along which a switch (74) is interposed, and - an electronic control board (76) for the switch (74) of the bypass circuit (70); in which the electrical path (72) of said at least one bypass circuit (70) extends between two ends which are connected to the nodes (20, 22) of the associated capacity unit (12a-12d) or to the nodes (20, 22) which delimit the series of several associated capacity units (12a-12d).

9. Battery (10) according to claim 8, wherein the bypass circuit (70) is powered by an independent current source (AL76): - of at least one cell (14) of the associated capacity unit (12a-12d) and a power supply (AL26) for the electronic board (26a-26d) controlling the switches (24p, 24s) of this associated capacity unit (12a-12d); or - cells (14) of the series of associated capacity units (12) and power supplies (AL26) of the electronic boards (26a-26d) for controlling the switches (24p, 24s) of these associated capacity units.

10. Vehicle propelled partially or totally by an electric motor and comprising a battery (10) according to any one of the preceding claims for powering the electric motor.

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