FR3151407A1 - DEVICE FOR DETECTING A VOLTAGE ANOMALY OF AT LEAST ONE BATTERY ACCUMULATOR AND BATTERY ACCUMULATOR MANAGEMENT SYSTEM COMPRISING SUCH A DEVICE - Google Patents

Abstract

The invention relates to a 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 (SA, SA') indicative 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 (SA, SA') of said 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, said control stage (12) being configured to send a signal (ST) indicative of an overvoltage or an undervoltage to said management system (3) based on the pulse train (Ti) from said at least one conversion stage (10). Figure to be published with the abstract: [Fig. 3]

Description

DEVICE FOR DETECTING A VOLTAGE ANOMALY OF AT LEAST ONE BATTERY ACCUMULATOR AND BATTERY ACCUMULATOR MANAGEMENT SYSTEM COMPRISING SUCH A DEVICE

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.

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 management system (or “Battery Management System” in English).

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.

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.

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

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 trips the circuit breaker device if these electrical quantities take on values corresponding to abnormal operating conditions.

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

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

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 any 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.

These detection means D are of course supplied directly with voltage by the cell, however, since the cell voltages add up, the last detection means see a voltage higher than 20V, which implies having electronic components that can accept this type 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 a battery 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 are therefore unsuitable for aerospace or aeronautical applications.

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, energy-efficient and economical.

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 into a pulse train the output signal of said at least one detection stage;
– 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.

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

According to one possible feature, 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 electrical consumption of the electronic components carrying out the conversion of the signal from the input stage into a pulse train.

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.

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 sets being connected to the same control stage.
Advantageously, the device can thus comprise separate input stages for detecting an overvoltage or an undervoltage at the terminals of a battery cell, but a common control stage, in order to reduce the costs and the number of electronic components required.

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.

According to another possible feature, the first substage 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, thus limiting, or even avoiding, the 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.

According to another possible feature, 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.

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.

According to another possible feature, the first substage of the control stage includes 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.

According to another possible feature, the second substage 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, because 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 proper operation of the second stage despite low voltages, where logic gates do not operate within the framework of these orders of magnitude of voltage.

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

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

Other characteristics and advantages of the invention will become apparent from the description which follows on the one hand, and from several examples of embodiment given for information purposes and without limitation with reference to the attached schematic drawings on the other hand, in which:
- there illustrates a very schematic view of a prior art electric battery and several of its cells connected in series;
- there illustrates a very schematic view of an electric battery comprising a battery accumulator management system according to the invention;
- there is a very schematic and functional view of a battery cell voltage anomaly detection device for a battery management system. ;
- there is a very schematic, enlarged and partial view of the device of the ;
- there is a very schematic, enlarged and detailed view of the device of the .

Of course, the features, variants and different embodiments of the invention may be combined with each other, in various combinations, to the extent 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.

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, the elements common to several figures retain the same reference.

There 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.).

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.

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 an overcurrent, an overvoltage (in particular when charging it), an undervoltage (in particular when discharging it), overheating, etc.

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.

There illustrates a very schematic and functional view of a detection 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.

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 supplied by a voltage U ₊ and U _- (respectively positive and negative terminals of the cell) and to deliver at output a signal S _A , S _A ' indicative of an overvoltage and/or an undervoltage at said terminals of the cell;
– at least one conversion stage 10 configured to convert into a pulse train T _i the output signal S _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 a signal S _T indicating an overvoltage or an undervoltage to said management system 3 based on the pulse train T _i from said at least one conversion stage 10.

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

Thus, for a cell having a nominal voltage of 3.3 V, it is considered that there is an overvoltage if the voltage at the terminals of the cell is greater than 3.5 V, or even up to 3.9 V, while it is considered an undervoltage when the voltage at the terminals of the cell is of the order of 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 5 V.

Thus, 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 pulse train T _i of fixed frequency, for example a frequency between 3 and 200 kHz, and for example a frequency of substantially 6.42 kHz.

The pulse train T _i , 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 _i 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 this is an overvoltage or an undervoltage, or the disconnection of the battery 1.

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 _i , 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 _i comprises for example at least 50 pulses, and preferably at least 100, so that the control stage 12 does not emit an output signal S _T .

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.

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 output a signal S _A ' indicative of an undervoltage at said terminals of the cell, as well as a conversion stage 10 (distinct from that of the first assembly 14).

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.

There , for its part, is a schematic, partial and enlarged view of the detection device of the , 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.

Indeed, said conversion stage 10 comprises:
– a first sub-stage 10a configured to convert the output signal S _A of the 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 into a pulse train T _i .

Control stage 12, for its part, comprises at least:
– a first sub-stage 12a configured to convert the pulse train T _i 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 an overvoltage or an undervoltage by comparing the average continuous signal S _m to a reference signal, for example a reference voltage V _REF .

Note that the reference voltage value V_REF is advantageously identical for all operational amplifiers AO₁and AO₃of the different stages 8 and 12, although these may be separate and independent voltages.

Furthermore, said input stage 8, 8' comprises at least one operational amplifier AO ₁ , called the first operational amplifier, mounted as a comparator, for example an inverter.
Said first operational amplifier AO ₁ 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).

The non-inverting input of said operational amplifier AO ₁ 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 R ₁ and R ₂ mounted as a divider bridge, while the inverting input is supplied by a reference voltage V _REF 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 C ₁ , called the first capacitor.

It should be noted that this first capacitor _C1 is intended in particular to compensate for any problems with noise and/or voltage fluctuations serving as a reference for the comparator assembly.

The input stage 8, 8' may also comprise a second capacitor C ₂ mounted in parallel with the foot resistor R ₁ (or first resistor) of the divider bridge or mounted in series with the second resistor R ₂ , the assembly comprising the second resistor R ₂ and the second capacitor C ₂ forming a series RC circuit enabling a gradual increase, for example over 30 to 40 seconds, of the voltage delivered by the divider bridge to the non-inverting input of the first operational amplifier AO ₁ . 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 _SA if the voltage at the non-inverting input becomes greater than or equal to or the reference voltage V _REF at the inverting input of the first operational amplifier AO ₁ .

In addition, the input stage 8, 8' advantageously comprises:
– a diode _D1 , 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 C ₃ , called the third capacitor, connected on the one hand to the output of the first operational amplifier AO ₁ 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'.

It should also be noted that the first diode _D1 comprises an anode connected to the positive terminal of the cell, and a cathode connected to the second resistor _R2 .

The first sub-stage 10a of the conversion stage 10 comprises an operational amplifier AO ₂ , called the second operational amplifier, mounted as an astable multivibrator. Said second operational amplifier AO ₂ 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.

More particularly, the first sub-stage 10a also comprises three resistors R ₃ , R ₄ and R ₅ , called respectively the third, fourth and fifth resistor, as well as a capacitor C ₄ , called the fourth capacitor.

The output of the second operational amplifier AO ₂ is thus connected, on the one hand, via the third resistor R ₃ , to the non-inverting input of the second operational amplifier AO ₂ , and on the other hand, via a fourth resistor R ₄ to the inverting input of the second operational amplifier AO ₂ . The fifth resistor R ₅ , for its part, is connected to the non-inverting input of the operational amplifier AO ₂ , as well as to the third resistor R ₃ , while the fourth capacitor C ₄ is connected, on the one hand, to the inverting input of the operational amplifier AO ₂ and to the fourth resistor R ₄ , and on the other hand, to the negative terminal of the cell of the battery 1 or to a ground G.

Advantageously, the first sub-stage 10a comprises:
– a resistor R ₆ , called the sixth resistor, interposed between the fourth capacitor C ₄ and the non-inverting input of the operational amplifier AO ₂ (and also connected to the fourth resistor R ₄ ), the association of the sixth resistor R ₆ and the fourth capacitor C ₄ 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 R ₇ , 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 R ₃ and R ₅ , as well as the non-inverting input of the second operational amplifier AO ₂ , the combination of the seventh resistor R ₇ and the resistor R ₃ making it possible to adjust values linked to the hysteresis of the assembly of the astable multivibrator.

Thus, as soon as the output signal S _A is applied to the input of the first sub-stage 10a, the second operational amplifier AO ₂ mounted as an astable multivibrator generates, at the output of the first sub-stage 10a, an oscillating signal S _O , in particular a square signal having a frequency of 6.42 kHz.

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

Said pulse transformer assembly thus comprises:
– a transformer T _R having a primary and a secondary;
– at least two diodes D ₂ and D ₃ , for example Schottky diodes, called respectively second and third diodes, configured to rectify the pulses coming from the secondary of the 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 eliminate the pulses having a negative voltage value;
– a transistor T ₁ , 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 R ₈ , 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 .

It will be noted 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 T ₁ to a time less than the saturation of the transformer T _R .

The primary of the transformer T _R is further connected to the positive terminal of the cell, and therefore supplied by a voltage U ₊ , advantageously via a resistor R ₉ , called the ninth resistor, the latter making it possible for example to limit the value of the current flowing in the transformer T _R (in particular in the primary). In addition, said second sub-stage 10b advantageously comprises a diode D ₄ , for example a Schottky diode, called the fourth diode, mounted in parallel with the primary, therefore connected both to the ninth resistor R ₉ and to the collector of the transistor T _{1 ,} in particular to limit the value of the current that can flow through the transistor T ₁ . The fourth diode D ₄ thus comprises an anode connected to the collector of the transistor T ₁ , and a cathode connected to the ninth resistor R ₉ . The fourth diode D ₄ acts as a freewheel diode, avoiding overloading of the transistor T ₁ , in particular by dissipating the energy accumulated by inductance when the transistor T ₁ opens.

It will also be noted that the second diode D ₂ is connected in parallel with the secondary of the transformer T _R , and that the secondary and the anode of the second diode D ₂ are connected to a ground G, for example the ground of the management system 3. While the third diode D ₃ is in series with the secondary and the second diode D ₂ , more particularly the anode of the third diode D ₃ is connected to the cathode of the second diode D ₂ and to the secondary.

The first sub-stage 12a of the control stage 12 comprises, for its part, at least one envelope detector assembly, the latter comprising at least one inductance _L1 and one capacitor _C5 , called the fifth capacitor, mounted in parallel, and forming a parallel RC assembly. The inductance _L1 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.

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

The second sub-stage 12b of the control stage 12 comprises an operational amplifier AO ₃ , called the third operational amplifier, mounted as a comparator, for example an inverter.

Said third operational amplifier AO ₃ 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 management system 3 of the battery accumulators.

The non-inverting input of said operational amplifier AO ₃ is at the envelope detector assembly, therefore at the inductance L ₁ and at the fifth capacitor C ₅ , while the inverting input is supplied by a reference voltage V _REF and is connected to ground G, for example ground G of the management system 3, advantageously via a capacitor C ₆ , called the sixth capacitor.

Thus, when there is a pulse train T _i at the input of the first sub-stage 12a, the envelope detector assembly delivers at the non-inverting input of the third operational amplifier AO ₃ a DC voltage greater than the reference voltage V _REF , which leads to the generation of a signal S _T at its output, here a DC voltage, signal S _T which is interpreted by the management system 3 as indicative of a voltage anomaly of the battery cell and which is configured to trigger suitable responses, alerts, battery disconnection, rebalancing, etc.

It should also be noted that diodes _D1 to _D4 are advantageously Schottky type diodes due to their lower threshold voltage than, for example, Zener diodes, and the speed of their switching.

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 (11)

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 an overvoltage and/or an undervoltage at said terminals of the cell;
– at least one conversion stage (10) configured to convert into a pulse train (T _i ) the output signal (S _A , S _A ' ) 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 an undervoltage to said management system (3) based on the pulse train (T _i ) from said at least one conversion stage (10). Device (6) according to the preceding claim, characterized in that said at least one input stage (8, 8') comprises at least one operational amplifier (AO ₁ ) mounted as a comparator to detect a voltage anomaly at said terminals of a battery cell. 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 as 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 as 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). 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 output signal (S _A , S _A ' ) 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 (T _i ). Device (6) according to the preceding claim, characterized in that the first sub-stage (10a) of the conversion stage (10) comprises an operational amplifier (AO ₂ ) mounted as an astable multivibrator. 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 (T _i ). 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 (T _i ) into a continuous signal (S _m );
– a second sub-stage (12b) configured to output a signal (S _T ) indicative of an overvoltage or an undervoltage by comparing the continuous signal (S _m ) to a reference signal (V _REF ). 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. Device (6) according to the preceding claim, characterized in that the second sub-stage (12b) of the control stage comprises an operational amplifier (AO ₃ ) mounted as a comparator. Battery accumulator management system (3), characterized in that said management system (3) comprises a device (6) for detecting a voltage anomaly according to any one of the preceding claims. Electric battery (1), characterized in that said battery comprises a management system (3) of the battery accumulators according to the preceding claim.