Device for detecting a voltage anomaly of at least one battery accumulator and battery accumulator management system comprising such a device

Abstract

The invention relates to a device (6) for detecting a voltage anomaly of at least one battery accumulator, the device (6) comprising: - at least one input stage (8, 8') configured to be connected to the terminals of a battery cell and to output a signal (SA, SA') indicating an overvoltage and / or an undervoltage at the terminals of the cell; - at least one conversion stage (10) configured to convert the output signal (SA, SA') of the at least one detection stage (8, 8') into a pulse train (Ti); - a control stage (12) configured to be connected to a battery accumulator management system, the control stage (12) being configured to send a signal (ST) indicating an overvoltage or an undervoltage to the management system (3) on the basis of the pulse train (Ti) originating from the at least one conversion stage (10).

Description

Description Title of the invention: DEVICE FOR DETECTING A VOLTAGE ANOMALY OF AT LEAST ONE BATTERY ACCUMULATOR AND MANAGEMENT SYSTEM OF BATTERY ACCUMULATORS COMPRISING SUCH A DEVICE

[0001] The technical context of the present invention is that of electric batteries, and in particular batteries with high electric current, in particular greater than 50 A, and preferably greater than 500 A, for example for aeronautical and / or aerospace applications.

[0002] A battery generally comprises several battery modules forming a set which can also be connected to an external bus allowing data to be sent to a monitoring system, a system generally referred to as a battery accumulator management system (or “Battery Management System” in English).

[0003] The battery accumulator management system is notably configured to measure various physical quantities relating to the battery, and to the battery modules, such as voltages, currents, temperatures, internal resistances, etc., but also includes protection circuits to prevent the battery from operating under abnormal operating conditions, conditions which may damage the battery and cause human and / or material damage.

[0004] Abnormal operating conditions generally include: overvoltages, overcurrents, undervoltages, excessively high battery temperature, short circuits, etc., i.e. all parameters that do not correspond to a nominal operating range of the battery.

[0005] Battery management systems therefore include safety devices, such as a disconnecting device configured to cut the battery's electrical connections with the outside (and therefore electrically isolate it) in the event of abnormal operating conditions.

[0006] Such circuit breaker devices are generally controlled by a control circuit, forming part of the management system, which monitors the values ​​of certain electrical quantities, for example the voltage at the battery terminals and which triggers the circuit breaker device if these electrical quantities take on values ​​corresponding to abnormal operating conditions.

[0007] A battery, for example Lithium-Ion, intended for aeronautical applications and / or aerospace can present voltages ranging from a few tens of volts to more than a thousand volts, with discharge currents of between ten and a hundred amperes.

[0008] Such batteries of course include several cells, or accumulators, arranged in series and in parallel, we can for example have 8 C cells of 3.3 Volts connected in series as illustrated in [Fig.1]. The sum of this series of C battery cells generating an overall voltage of approximately 26.4 V.

[0009] Thus, when it is necessary to monitor each of these cells individually, in particular to see whether they are balanced with respect to each other, that is to say that they do not present undervoltage or overvoltage with respect to their nominal voltage, it is usual to place a detection means D at the terminals of each of the cells.

[0010] These detection means D are of course powered directly by the cell, however, as the cell voltages add up, the last detection means see a voltage higher than 20V, which implies having electronic components that can accept this kind of voltage, and preferably voltages of at least 28V, components that are sometimes difficult to find and / or generally more expensive. Furthermore, in the case of batteries with much higher voltages, for example 1000V, apart from optocouplers, it is not possible to find suitable electronic components. Unfortunately, optocouplers are expensive, energy-intensive components that are sensitive to solar particles, and therefore unsuitable for aerospace or aeronautical applications.

[0011] It is therefore necessary to find a solution that allows the use of standard electronic components, for example with nominal voltage ranges between 0 and 3.3 V, while being robust, low-power and economical.

[0012] The present invention thus proposes to remedy at least one of the aforementioned drawbacks by proposing a new type of device for detecting a voltage anomaly of at least one battery accumulator, said device comprising: - at least one input stage configured to be connected to the terminals of a battery cell and to output a signal indicative of an overvoltage and / or an undervoltage at said terminals of the cell; - at least one conversion stage configured to convert the output signal of said at least one detection stage into a pulse train; - a control stage configured to be connected to a battery accumulator management system, said control stage being configured to send a signal indicative of an overvoltage or an undervoltage to said management system based on the pulse train from said at least one conversion stage.

[0013] The device according to the invention has a simple and robust architecture allowing the use of inexpensive and easily available electronic components, while having low nominal operating voltages, for example of the order of 3.3V, thus greatly minimizing the power consumption of a device intended to monitor voltage anomalies at the terminals of an electric battery cell.

[0014] According to one possible characteristic, the pulse train has a fixed frequency, for example a frequency between 3 and 200 kHz, and for example substantially 6.42 kHz. The frequency of the pulse train generated by the conversion stage is advantageously fixed to minimize the noise and the power consumption of the electronic components converting the signal from the input stage into a pulse train.

[0015] According to another possible characteristic, said at least one input stage comprises at least one operational amplifier mounted as a comparator to detect a voltage anomaly at said terminals of a battery cell.

[0016] According to another possible characteristic, said device comprises a first set and a second set: - the first assembly comprising an input stage configured to deliver as output a signal indicative of an overvoltage at said terminals of the cell, as well as a conversion stage; - the second assembly comprising an input stage configured to output a signal indicative of an undervoltage at said terminals of the cell, as well as a conversion stage; each of said first and second assemblies being connected to the same control stage. Advantageously, the device can thus comprise separate input stages for detecting an overvoltage or undervoltage at the terminals of a battery cell, but a common control stage, in order to reduce costs and the number of electronic components required.

[0017] According to another possible characteristic, said at least one conversion stage comprises at least: - a first sub-stage configured to convert the output signal of the input stage into an oscillating signal, for example a square signal with variable duty cycle; - a second sub-stage configured to convert the oscillating signal from the first sub-stage into a pulse train.

[0018] According to another possible feature, the first sub-stage of the conversion stage comprises an operational amplifier mounted as an astable multivibrator. Thus, the first sub-stage of the conversion stage operates advantageously with both types of voltage anomalies, overvoltage or undervoltage, limiting, or even thus avoiding adaptations or modifications to be made to this first sub-stage depending on the anomaly intended to be detected. This makes it possible, among other things, to reduce costs and simplify the manufacture of a device according to the invention.

[0019] According to another possible characteristic, the second sub-stage of the conversion stage comprises at least one pulse transformer configured to convert the oscillating signal from the first sub-stage into a pulse train.

[0020] According to another possible characteristic, the control stage comprises at least: - a first sub-stage configured to convert the pulse train into a continuous signal; - a second sub-stage configured to output a signal indicative of an overvoltage or undervoltage by comparing the continuous signal to a reference signal.

[0021] According to another possible feature, the first sub-stage of the control stage comprises an envelope detector assembly. The envelope detector assembly makes it possible in particular to transform the pulse train from the conversion stage into a continuous signal, for example a continuous voltage, preferably less than 5V.

[0022] According to another possible feature, the second sub-stage of the control stage comprises an operational amplifier mounted as a comparator. The second sub-stage of the control stage advantageously comprises an operational amplifier, since this type of electronic component is capable of operating with pulse trains having low voltage values ​​at the output of the second conversion sub-stage, for example of the order of a few volts, or even of the order of 1 Volt. This therefore makes it possible to ensure the correct operation of the second stage despite low voltages, where logic gates do not operate within these voltage orders of magnitude.

[0023] The invention also relates to a system for managing battery accumulators, characterized in that said management system comprises a control circuit as defined above.

[0024] The invention further relates to an electric battery, characterized in that said battery comprises a device for detecting a voltage anomaly as defined above.

[0025] Other characteristics and advantages of the invention will become apparent from the following description on the one hand, and from several examples of embodiment given for informational and non-limiting purposes with reference to the attached schematic drawings on the other hand, in which: - [Fig.l] illustrates a very schematic view of an electric battery of the prior art and several of its cells connected in series; - [Eig.2] illustrates a very schematic view of an electric battery comprising a battery accumulator management system according to the invention; - [Fig.3] is a very schematic and functional view of a battery cell voltage anomaly detection device for a management system of [Fig.2]; - [Fig.4] is a very schematic, enlarged and partial view of the device of [Fig.3]; - [Fig.5] is a very schematic, enlarged and detailed view of the device of [Fig.4].

[0026] Of course, the features, variants and different embodiments of the invention may be combined with each other, in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be imagined comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0027] In particular, all the variants and embodiments described can be combined with each other if there is no technical obstacle to this combination. In the figures, elements common to several figures retain the same reference.

[0028] [Fig. 2] illustrates a very schematic and functional view of an electric battery 1, for example a lithium-ion battery, advantageously intended for aeronautical or aerospace applications, which comprises battery accumulators 2, or cells, a battery accumulator management system 3 connected to said accumulators 2, system 3 also designated by the English acronym “BMS” for “Battery Management System”, as well as a communication circuit 4 connected to said management system 3 and configured to allow said system 3 to exchange information with the outside (information relating to the environment, the battery, the aircraft, etc.).

[0029] Said management system 3 is generally integrated into said battery 1, in order to monitor the various physical or electrical quantities characteristic of a battery 1 and / or its accumulators 2 (or cells), for example a voltage, an internal resistance, etc.

[0030] Said management system 3 is also configured to prevent the operation of the battery 1 outside its nominal operating range, that is to say that the system is configured to detect abnormal operating conditions of the battery (or its modules), such as overcurrent, overvoltage (in particular when charging it), undervoltage (in particular when discharging it), overheating, etc.

[0031] Such a system 3 may also comprise a locking circuit (not shown) configured to prevent the use of the battery 1, and therefore its operation, in particular if an abnormal operating condition is detected by the management system 3.

[0032] [Fig. 3] illustrates a very schematic and functional view of a device 6 for detecting a voltage anomaly of at least one accumulator or cell 2 of the battery 1, said detection device 6 being for example included or integrated into the management system 3.

[0033] Said detection device 6 thus comprises: - at least one input stage 8, 8' configured to be connected to the terminals of a battery cell (not shown), therefore powered by a voltage U + and U. (respectively positive and negative terminals of the cell) and to deliver an indicative signal S at the output A , S A ' of an overvoltage and / or an undervoltage at said terminals of the cell; - at least one conversion stage 10 configured to convert the output signal S into a pulse train Tj A , S A ' of said at least one detection stage 8, 8'; - a control stage 12 configured to be connected to the battery accumulator management system 3, said control stage 12 being configured to send an indicative signal S T of an overvoltage or undervoltage to said management system 3 based on the pulse train T ; from said at least one conversion stage 10.

[0034] Said at least one input stage 8, 8' is powered by a DC voltage measured at the terminals of a battery cell 1, a cell which is perhaps in series and / or in parallel with other cells. Said at least one input stage 8, 8' is thus configured to deliver at output a signal S A , S A ' only if said cell 2 has an overvoltage or undervoltage.

[0035] Thus, for a cell with a nominal voltage of 3.3 V, it is considered that there is an overvoltage if the voltage across the cell terminals is greater than 3.5 V, or even up to 3.9 V, while undervoltage is considered when the voltage across the cell terminals is around 1.7 V, and at least less than 2.2 V. Furthermore, said output signal S A , S A ' is advantageously a direct voltage, for example of the order of a few volts, but preferably less than 5V.

[0036] So when the output signal S A , S A ' is emitted by said at least one input stage 8, 8', the conversion stage 10 converts the signal S A , S A ' into a train of pulses T) of fixed frequency, for example a frequency between 3 and 200 kHz, and for example a frequency of substantially 6.42 kHz.

[0037] The T pulse train ;, corresponding to the output signal of the conversion stage 10, is sent (preferably directly) to the input of the control stage 12. Said control stage 12 converts the pulse train T ; into an output signal S T which triggers, in the management system 3, an alert indicating that one of the cells 2 of the battery 1 has a voltage anomaly, whether it is an overvoltage or a undervoltage, or disconnection of battery 1.

[0038] The emission of an output signal S T by the control stage 12 is in particular conditioned by the length of the pulse train T,, in particular to prevent transient fluctuations in voltages and / or noise from bringing up false positives of voltage anomalies. It will be noted that the pulse train T ; comprises for example at least 50 pulses, and preferably at least 100, so that the control stage 12 emits an output signal ST .

[0039] More particularly, in the embodiment shown, the detection device 6 comprises a first assembly 14 and a second assembly 16, each of said assemblies 14 and 16 being connected to the same control stage 12.

[0040] More particularly, the first assembly 14 comprises an input stage 8 configured to output a signal S A indicative of an overvoltage at said terminals of the cell, as well as a conversion stage 10. While the second assembly 16 comprises an input stage 8' configured to deliver at output an indicative signal S A ' of an undervoltage at said terminals of the cell, as well as a conversion stage 10 (distinct from that of the first assembly 14).

[0041] Of course, the input of the first and second sets 14 and 16, i.e. the respective input of the detection stages 8 and 8', are connected to the terminals of the same battery cell.

[0042] [Fig.4], for its part, is a schematic, partial and enlarged view of the detection device of [Fig.3], on which the structure of the conversion stage 10 of the first assembly 14 is detailed, but this more detailed description of said conversion stage 10 can be applied mutatis mutandis to the conversion stage 10 of the second assembly 16.

[0043] Indeed, said conversion stage 10 comprises: - a first sub-stage 10a configured to convert the output signal S A from input stage 8 into an oscillating signal S o , for example a square signal having a preferably variable duty cycle; - a second sub-stage 10b configured to convert the oscillating signal S o from the first sub-stage 10a in a pulse train T ; .

[0044] The control stage 12, for its part, comprises at least: - a first sub-stage 12a configured to convert the pulse train T ; from the conversion stage 10 into an average continuous signal S m : - a second sub-stage 12b configured to output a signal S T indicative of overvoltage or undervoltage by comparison of the average continuous signal S m to a reference signal, for example a reference voltage VRE F .

[0045] Note that the reference voltage value V REF is advantageously identical for all operational amplifiers AOi and AO3 of the different stages 8 and 12, although these may be separate and independent tensions.

[0046] Furthermore, said input stage 8, 8' comprises at least one operational amplifier AOi, called the first operational amplifier, mounted as a comparator, for example an inverter. Said first operational amplifier AOi thus has an inverting input, a non-inverting input, as well as a connected output, corresponding to the output of the input stage 8, 8', connected, preferably directly to the input of the conversion stage 10 (and more particularly to the input of the first sub-stage 10a).

[0047] The non-inverting input of said operational amplifier AOi is connected to the voltage across the terminals of the cell of the battery 1, advantageously via at least a first and a second resistor Ri and R2 mounted as a divider bridge, while the inverting input is supplied by a reference voltage VREF and is connected to the negative terminal (therefore under a voltage U.) of the battery cell or to a ground G, for example via a capacitor Ci, called the first capacitor.

[0048] It should be noted that this first capacitor Ci is intended in particular to compensate for possible noise problems and / or voltage fluctuations serving as a reference for the comparator assembly.

[0049] The input stage 8, 8' may also comprise a second capacitor C2 mounted in parallel with the foot resistor Ri (or first resistor) of the divider bridge or mounted in series with the second resistor R2, the assembly of the second resistor R2 and second capacitor C2 forming a series RC circuit allowing a gradual rise, for example from 30 to 40 seconds, of the voltage delivered by the divider bridge to the non-inverting input of the first operational amplifier AOp. Such a series RC circuit makes it possible, among other things, to avoid the detection of transient short circuits and therefore to avoid the untimely triggering of an output signal S. A if the voltage at the non-inverting input becomes greater than or equal to the reference voltage VREF at the inverting input of the first operational amplifier AOp

[0050] In addition, the input stage 8, 8' advantageously comprises: - a diode D h for example Schottky, called the first diode, mounted between the positive terminal of the battery cell and the second resistor R2, preventing, among other things, currents from flowing back towards the battery cell; - a capacitor C3, called the third capacitor, connected on the one hand to the output of the first operational amplifier AOi and, on the other hand, to the negative terminal of the battery cell, in particular to eliminate sudden fluctuations in the voltage of the output signal S A , and to limit the electromagnetic disturbances (or EMC) generated by the device 6, and more particularly by the input stage 8, 8'.

[0051] It should also be noted that the first diode Di includes an anode connected to the positive terminal of the cell, and a cathode connected to the second resistor R2.

[0052] The first sub-stage 10a of the conversion stage 10 comprises an operational amplifier AO2, called the second operational amplifier, mounted as an astable multivibrator. Said second operational amplifier AO2 thus has an inverting input, a non-inverting input, as well as a connected output, corresponding to the output of the first sub-stage 10a, connected, preferably directly to the input of the second sub-stage 10b.

[0053] More particularly, the first sub-stage 10a also comprises three resistors R3, R4 and R5, called respectively the third, fourth and fifth resistor, as well as a capacitor C4, called the fourth capacitor.

[0054] The output of the second operational amplifier AO2 is thus connected, on the one hand, via the third resistor R3, to the non-inverting input of the second operational amplifier AO2, and on the other hand, via a fourth resistor R4 to the inverting input of the second operational amplifier AO2. The fifth resistor R5, for its part, is connected to the non-inverting input of the operational amplifier AO2, as well as to the third resistor R3, while the fourth capacitor C4 is connected, on the one hand, to the inverting input of the operational amplifier AO2 and to the fourth resistor R4, and on the other hand, to the negative terminal of the cell of the battery 1 or to a ground G.

[0055] Advantageously, the first sub-stage 10a comprises: - a resistor R6, called the sixth resistor, interposed between the fourth capacitor C4 and the non-inverting input of the operational amplifier AO2 (and also connected to the fourth resistor R4), the association of the sixth resistor R6 and the fourth capacitor C4 allows the start of an oscillation in the assembly of the astable multivibrator (and the control of the rise time of the oscillating signal governing the assembly of the astable multivibrator); - a resistor R7, called the seventh resistor, located at the input of the first sub-stage 10a, and therefore connected, on the one hand, to the output of the input stage 8 and, on the other hand, to the third and fifth resistors R3 and R5, as well as the non-inverting input of the second operational amplifier AO2, the association of the seventh resistor R7 and the resistor R3 making it possible to adjust values ​​linked to the hysteresis of the assembly of the astable multivibrator.

[0056] So, as soon as the output signal SA is applied to the input of the first sub-stage 10a, the second operational amplifier AO2 mounted as an astable multivibrator generates, at the output of the first sub-stage 10a, an oscillating signal S o , including a square signal with a frequency of 6.42 kHz.

[0057] The second sub-stage 10b of the conversion stage 10 comprises, for its part, at least one pulse transformer assembly configured to convert the signal oscillating S o from the first sub-stage 10a in a pulse train T ; intended for the input of control stage 12.

[0058] Said pulse transformer assembly thus comprises: - a T transformer R presenting a primary and a secondary; - at least two diodes D2 and D3, for example Schottky diodes, called second and third diodes respectively, configured to rectify the pulses coming from the secondary of transformer T R (and therefore have at the output of the first sub-stage 12b only positive or negative pulses), for example the second diode D2 makes it possible to suppress pulses having a negative voltage value; - a transistor Ti, for example of the NPN type (operating both for a voltage anomaly linked to an overvoltage or an undervoltage, or even for any type of anomaly translated in the form of voltage), having a base, a collector and an emitter, said base being connected to the output of the first sub-stage 10a, for example via a resistor R8, called the eighth resistor, said emitter being connected to the negative terminal of the battery cell (or to a ground G) and said collector being connected to the primary of the transformer T R .

[0059] Note that the oscillating signal S o from the first sub-stage 10a has characteristics (for example voltage and / or frequency) limiting the opening time of the transistor Ti to a time less than the saturation of the transformer T R .

[0060] The primary of transformer T Ris further connected to the positive terminal of the cell, and therefore supplied by a voltage U + , advantageously by means of a resistor R9, called the ninth resistor, this making it possible, for example, to limit the value of the current flowing in the transformer T R (in particular to the primary). In addition, said second sub-stage 10b advantageously comprises a diode D4, for example a Schottky diode, called the fourth diode, mounted in parallel with the primary, therefore connected both to the ninth resistor R9 and to the collector of the transistor Ti in particular to limit the value of the current which can pass through the transistor Tp. The fourth diode D4 thus comprises an anode connected to the collector of the transistor Ti, and a cathode connected to the ninth resistor R9. The fourth diode D4 acts as a freewheel diode, avoiding overloading of the transistor T h in particular by dissipating the energy accumulated by inductance when the transistor Ti opens.

[0061] It should also be noted that the second diode D2 is mounted in parallel with the secondary of transformer T R , and that the secondary and the anode of the second diode D2 are connected to a ground G, for example the ground of the management system 3. While the third diode D3 is in series with the secondary and the second diode D2, more particularly the anode of the third diode D3 is connected to the cathode of the second diode D2 and to the secondary.

[0062] The first sub-stage 12a of the control stage 12 comprises, for its part, least one envelope detector assembly, the latter comprising at least one inductance Li and one capacitor C5, called the fifth capacitor, mounted in parallel, and forming a parallel RC assembly. The inductance Li and the fifth capacitor C5 are connected, on the one hand, to the cathode of the third diode D3 (the connection node thus corresponding to the input of the first sub-stage 12a), and on the other hand, to a ground G, for example the ground of the management system 3.

[0063] The envelope detector assembly thus makes it possible to transform the pulse train Tj from the conversion stage 10, and in particular from the second sub-stage 10b, into a continuous signal S m (medium), for example a direct voltage, preferably less than 5V, which is sent to the input of the second sub-stage 12b of the control stage 12.

[0064] The second sub-stage 12b of the control stage 12 comprises an operational amplifier AO3, called the third operational amplifier, mounted as a comparator, for example an inverter.

[0065] Said third operational amplifier AO3 thus has an inverting input, a non-inverting input, as well as a connected output, corresponding to the control output 12, connected, preferably directly to the battery accumulator management system 3.

[0066] The non-inverting input of said operational amplifier AO3 is to the envelope detector assembly, therefore to the inductance Li and to the fifth capacitor C5, while the inverting input is supplied by a reference voltage VREF and is connected to ground G, for example ground G of the management system 3, advantageously via a capacitor C6, called the sixth capacitor.

[0067] Thus, when there is a pulse train T) at the input of the first sub-stage 12a, the envelope detector assembly delivers at the non-inverting input of the third operational amplifier AO3 a DC voltage greater than the reference voltage V REF , which results in the generation of a signal S T at its output, here a continuous voltage, signal S T which is interpreted by the management system 3 as indicative of a battery cell voltage anomaly and which is configured to trigger appropriate responses, alerts, battery disconnection, rebalancing, etc.

[0068] It should also be noted that diodes Di to D4 are advantageously Schottky type diodes due to their lower threshold voltage than, for example, Zener diodes, and the speed of their switching.

[0069] In another variant embodiment of the invention not shown, the device 6 comprises a control stage 12 for each conversion stage 10 (and therefore for each input stage 8).

Claims

Claims

1. Device (6) for detecting a voltage anomaly of at least one battery accumulator, said device (6) comprising: - at least one input stage (8, 8') configured to be connected to the terminals of a battery cell and to output a signal (S A , S A ' ) indicative of overvoltage and / or undervoltage at said cell terminals; - at least one conversion stage (10) configured to convert into a pulse train (T ; ) the signal (S A , S A ' ) output of said at least one detection stage (8, 8'); - a control stage (12) configured to be connected to a battery accumulator management system, said control stage (12) being configured to send a signal (S T) indicative of an overvoltage or undervoltage in said management system (3) based on the pulse train (1)) from said at least one conversion stage (10).

2. Device (6) according to the preceding claim, characterized in that said at least one input stage (8, 8') comprises at least one operational amplifier (AOi) mounted as a comparator to detect a voltage anomaly at said terminals of a battery cell.

3. Device (6) according to the preceding claim, characterized in that said device (6) comprises a first assembly (14) and a second assembly (16): - the first assembly (14) comprising an input stage (8) configured to deliver at output a signal (S A ) indicative of an overvoltage at said terminals of the cell, as well as a conversion stage (10); - the second assembly comprising an input stage (8') configured to deliver at output a signal (S A ' ) indicative of an undervoltage at said terminals of the cell, as well as a conversion stage (10); each of said first and second sets (14, 16) being connected to the same control stage (12).

4. Device (6) according to the preceding claim, characterized in that said at least one conversion stage (10) comprises at least: - a first sub-stage (10a) configured to convert the signal (S A , S A ' ) output of the input stage (8) into an oscillating signal (S o ) ; - a second sub-stage (10b) configured to convert the oscillating signal (S o ) from the first sub-stage (10a) into a pulse train Œ).

5. Device (6) according to the preceding claim, characterized in that the first sub-stage (10a) of the conversion stage (10) comprises an operational amplifier (AO2) mounted as an astable multivibrator.

6. Device (6) according to claim 4 or 5, characterized in that the second sub-stage (10b) of the conversion stage (10) comprises at least one pulse transformer configured to convert the oscillating signal (S o ) from the first sub-stage (10a) into a pulse train Œ).

7. Device (6) according to any one of the preceding claims, characterized in that the control stage (12) comprises at least: - a first sub-stage (12a) configured to convert the pulse train (1) into a continuous signal (S m ) ; - a second sub-stage (12b) configured to output a signal (S T) indicative of overvoltage or undervoltage by comparison of the continuous signal (S m ) to a reference signal (VREF).

8. Device (6) according to the preceding claim, characterized in that the first sub-stage (12a) of the control stage (12) comprises an envelope detector assembly.

9. Device (6) according to the preceding claim, characterized in that the second sub-stage (12b) of the control stage comprises an operational amplifier (AO3) mounted as a comparator.

10. Management system (3) for battery accumulators, characterized in that said management system (3) comprises a device (6) for detecting a voltage anomaly according to any one of the preceding claims.

11. Electric battery (1), characterized in that said battery comprises a management system (3) of the battery accumulators according to the preceding claim.

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