FR3151139A1 - LOCKING CONTROL DEVICE FOR BATTERY ACCUMULATOR MANAGEMENT SYSTEM AND BATTERY ACCUMULATOR MANAGEMENT SYSTEM EQUIPPED WITH SUCH DEVICE - Google Patents

Abstract

The invention relates to a locking control device (5) for a battery accumulator management system (3), said device comprising at least: – a stage (7) for storing abnormal operating conditions of the battery, said stage being configured, on the one hand, to receive as input one or more voltages (VUV, VOV, VT) relating to abnormal operating conditions, and on the other hand, to permanently store the occurrence of an abnormal operating condition of the battery; – a locking control stage (9) whose input is connected to the output of said storage stage (7) and whose output is configured to be connected to said battery accumulator management system (3), said control stage (7) being configured to send a locking command to said battery accumulator management system (9) if an abnormal operating condition is stored in said storage stage (7). Figure to be published with the abstract: [Fig. 2]

Description

LOCKING CONTROL DEVICE FOR BATTERY ACCUMULATOR MANAGEMENT SYSTEM AND BATTERY ACCUMULATOR MANAGEMENT SYSTEM EQUIPPED WITH SUCH 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. More particularly, the invention relates to a locking control device for a system for managing such batteries.

A battery generally comprises several battery modules, generally formed of several accumulators or cells, forming a unit 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).

The battery accumulator management system is notably configured to measure various physical quantities relating to the battery, the modules and/or battery cells, 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 electrical connections of the battery with the outside (and therefore electrically isolate it) in the event of abnormal operating conditions.

However, once the circuit breaker associated with the battery has tripped, rendering the battery inoperable, there is nothing to prevent the circuit breaker from being reset and the battery being used again, regardless of any checking and/or testing of the battery.

It is therefore necessary to provide a safety feature that prevents any use of said battery following an abnormal operating condition, until the battery has been checked and it is certain that it is not dangerous to use.

The present invention thus proposes to remedy at least one of the aforementioned drawbacks by proposing a new type of locking control device for a battery accumulator management system,
said device comprising at least:
– a stage for storing abnormal operating conditions of the battery, said stage being configured, on the one hand, to receive as input one or more voltages relating to abnormal operating conditions, and on the other hand, to permanently store the occurrence of an abnormal operating condition of the battery;
– a locking control stage whose input is connected to the output of said storage stage and whose output is configured to be connected to said battery accumulator management system;
said control stage being configured to send a locking command to said battery accumulator management system if an abnormal operating condition is stored in said storage stage.

It should be noted that here, the term “battery” refers to the battery as a whole, or one or more of its sub-elements, i.e. an accumulator or battery cell, or several accumulators or cells, connected in series and/or in parallel. It should also be noted that “permanent storage” refers to the fact that the device according to the invention, and more particularly the storage stage, is configured to retain a state, and therefore the information, independently of a power supply (or another physical parameter), the information therefore being able to be retained over a long period of time regardless of the environment in which the battery is located.

The locking control device according to the invention makes it possible to memorize certain abnormal operating conditions of the battery, in particular by being connected to electrical quantities, here voltages, reflecting an overvoltage, an undervoltage and/or an abnormal temperature (too high or too low), and to control the locking of the battery via the battery accumulator management system. Once the battery is locked, it is rendered inoperative and cannot be used, no action can be performed by it, such as a current draw. The device according to the invention thus guarantees that the battery, whatever the defect that caused it to be blocked, cannot present a danger to an operator or equipment to which the battery is connected.

According to a possible characteristic, said storage stage comprises a disconnection member configured to store an abnormal operating condition of the battery.
The storage of an abnormal operating condition of the battery is therefore carried out by means of the disconnection, for example irreversible, or not of a disconnection member. Such a disconnection member is advantageously a fuse, for example of the blade type, with a transparent glass tube, etc. or a circuit breaker, preferably non-resettable, or inaccessible to the user of the battery if it is resettable.

According to another possible characteristic, said disconnecting member is configured to permanently memorize an abnormal operating condition of the battery.
Advantageously, said disconnecting member thus passes from one physical state to another irreversibly following an abnormal operating condition of the battery.

According to another possible characteristic, said circuit breaker is configured to circuit break if an input voltage of the storage stage is greater than or equal to a predetermined value.
The predetermined value triggering the storage of an abnormal operating condition is chosen in such a way as to avoid the tripping of the circuit breaker following fluctuations in the input voltages.

According to another possible characteristic, said storage stage comprises at least one switch configured to trigger the disconnection of said disconnection member as a function of the input voltage of said storage stage.

According to another possible characteristic, said at least one switch is a transistor, for example of the MOSFET type.
Advantageously, said switch is a MOSFET transistor, for example of type N, allowing voltage control of the triggering of the disconnecting member, and therefore of the memorization of an abnormal operating condition of the battery.

According to another possible characteristic, said storage stage is configured to deliver as output:
– a first voltage value if the circuit breaker has not stored any abnormal operating condition;
– a second voltage value if the circuit breaker has stored an abnormal operating condition;
said control stage being configured to send a locking command to said battery accumulator management system if the control stage receives the second voltage value as input.

According to another possible characteristic, said control stage comprises at least one operational amplifier mounted as a comparator.
Said control stage advantageously comprises an operational amplifier mounted as a comparator, for example an inverter, making it possible, depending on the state of the disconnecting member, to deliver an output signal triggering or not the locking of the battery by the battery accumulator management system.

The invention also relates to a battery accumulator management system, characterized in that said system comprises a locking control device as defined above.

The invention further relates to an electric battery, advantageously for aeronautical and/or aerospace applications, characterized in that said battery comprises a battery accumulator management system 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 and side view of an electric battery equipped with a battery accumulator management system;
- there illustrates a schematic view of a locking control device according to the invention;
- there is a 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. Furthermore, in the various 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, 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 the system 3 to exchange information with the outside (information relating to the environment, the battery, the aircraft, etc.), for example with a computer, a server, a sensor, 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 of one or more of its cells), 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 has previously occurred.

There thus illustrates a diagram of the locking control device 5 of the locking circuit, the activation of said locking circuit causing the electrical disconnection of the battery 1, in order to protect it from possible damage. The locking circuit comprises for example an electromechanical or semiconductor relay.

Said device 5 thus comprises at least:
– a stage 7 for storing abnormal operating conditions of the battery, said stage 7 being configured, on the one hand, to receive as input one or more voltages V _UV , V _OV , V _T relating to abnormal operating conditions of the battery 1 (or one or more of its cells 2), and on the other hand, to permanently store the occurrence of an abnormal operating condition of the battery 1;
– a locking control stage 9 whose input is connected to the output of said storage stage 7 and whose output is configured to be connected to said battery accumulator management system 3, and more particularly to the locking circuit.

It should be noted that by battery we mean the battery 1 as a whole, or one or more of its sub-elements, i.e. a single accumulator 2, or battery cell, or several accumulators 2, or cells, connected in series and/or in parallel.

Thus, the storage stage 7 is connected to circuits delivering voltages representing different abnormal operating conditions of said battery and/or its modules, these circuits being for example integrated into said management system 3. There are advantageously three voltages reflecting abnormal conditions, respectively linked to an undervoltage V _UV , to an overvoltage V _OV and/or a temperature problem V _T (i.e. an excess temperature or a temperature that is too low).

Thus, as soon as one of the input voltages V _UV , V _OV , V _T exceeds a threshold value, previously determined (here a value common to said voltages), indicative of an abnormal operating condition, then there is permanent storage of this state by said storage stage 7.

Furthermore, said control stage 9 is configured to send a locking command (or signal) S _V to said management system 3, when the storage stage 7 has stored an abnormal operating condition.

There is an enlarged and detailed schematic view of the locking control device 5, and in particular of the storage stages 7 and locking control stages 9.

Thus, the storage stage 7 comprises at least:
– an input resistor R ₁ , called the first resistor, and a second resistor R ₂ mounted as a divider bridge, said bridge being supplied with voltage by one or more of the input voltages V _UV , V _OV , V _T relating to an abnormal operating condition of the battery 1;
– a disconnecting member F ₁ configured to memorize an abnormal operating condition of the battery and powered by a direct voltage V _CC , advantageously via a current limiting resistor R _LI;
– a MOSFET type transistor T ₁ having a gate, a source and a drain, the gate of the transistor being supplied by one or more input voltages V _UV , V _OV , V _T , this via the divider bridge formed by the first and second resistors R ₁ and R ₂ , the source being connected to a ground G (by the ground of the management system 3), while the drain is supplied by the direct voltage V _CC via the disconnecting member F ₁;
– a storage stage output 7 which is connected to a node N _D , or drain node, located between the fuse F ₁ and the drain of the transistor T ₁ and which connects the storage stage 7 to the input of the latch control stage 9.

The storage stage 7 further advantageously comprises:
– a capacitor C ₁ , called the first capacitor, mounted in parallel with the second resistor R ₂ , and forming a parallel RC circuit which is connected, on the one hand, between the first resistor R ₁ and the gate of the transistor T ₁ , and on the other hand, to ground G;
– a resistor R ₃ , called the third resistor, and a resistor R ₄ , called the fourth resistor, forming another divider bridge which is connected to the drain node N _D and to the input of the control stage 9;
– a capacitor C ₂ , called the second capacitor, mounted in parallel with the fourth resistor R4, and thus forming a parallel RC circuit, an RC circuit connected, on the one hand, to the drain node N _D , via the third resistor R ₃ , and on the other hand, to ground G.

More particularly, it will be noted that the first divider bridge formed by the first and second resistors R ₁ and R ₂ , and the parallel RC circuit, formed by the second resistor R ₂ and the first capacitor C ₁ , respectively make it possible to reduce the voltage applied to the gate of the transistor T ₁ (for example to 0.33 V), and to allow a gradual increase in the voltage applied to the gate of the transistor T ₁ (thus avoiding an overvoltage which could damage it).

The second divider bridge formed by the third and fourth resistors R ₃ and R ₄ makes it possible, among other things, to limit the output voltage of the storage stage 7 which supplies the inverting input of the operational amplifier AO ₁ .

More particularly, said circuit breaker F ₁ is advantageously a fuse, for example of the blade type, with a transparent glass tube, etc. or a circuit breaker, preferably non-resettable, or inaccessible to the user of the battery 1 if the latter is resettable. Thus, said circuit breaker F ₁ is configured to permanently store an abnormal operating condition of the battery, by changing from one physical state to another irreversibly.

It should be noted that permanent storage and irreversible change of state mean that the disconnecting device _F1 is not configured to return to its initial state spontaneously, for example when there is no more electrical power supply.

Thus, if said disconnecting member is configured to change state if an input voltage V _UV , V _OV , V _T of the storage stage 7 is greater than or equal to a predetermined value.

Transistor _T1 , for its part, acts as a switch configured to trigger the disconnection of said disconnection member as a function of the value of the input voltages _VUV , _VOV , _VT of said storage stage 7 (in particular when one of these voltages exceeds the predetermined value).

Indeed, the voltage between the drain and the source of the transistor T ₁ is fixed by the direct voltage V _CC , whereas depending on the gate voltage of the transistor T ₁ depending on the value of the input voltages V _UV , V _OV , V _T , the value of the current flowing through the circuit breaker F ₁ causes its circuit breaker to be disconnected when the value of the input voltages V _UV , V _OV , V _T exceeds the predetermined threshold value.

Thus, said storage stage 7 is configured to deliver as output:
– a first voltage value V _N if the circuit breaker F ₁ has not stored any abnormal operating condition;
– a second voltage value V _A if the circuit breaker F ₁ has stored an abnormal operating condition.

The locking control stage 9 comprises, for its part, at least one operational amplifier AO ₁ mounted as a comparator. Said operational amplifier AO ₁ has an inverting input, a non-inverting input, as well as an output connected to said locking circuit of the management system 3.

The inverting input of said operational amplifier AO ₁ is connected to the output of the storage stage 9, while the non-inverting input is supplied by a reference voltage V _REF and is connected to ground G, for example via a capacitor C ₃ , called the third capacitor. It will be noted that this third capacitor C ₃ has the particular purpose of reducing the input impedance of the non-inverting input of the operational amplifier AO ₁ .

The output of the operational amplifier AO ₁ corresponds to the output of the control stage 9 and is therefore connected to the locking circuit of said management system 3.

The operational amplifier AO ₁ , mounted here as an inverting comparator, allows, depending on the state of the disconnecting device F _{1 ,} to deliver an output signal S _V triggering or not the locking of the battery 1 by the battery accumulator management system 3.

Thus, if the output voltage of the storage stage 7 corresponds to the first voltage value V _N then this is higher than the reference voltage V _REF , and the output voltage is -V _SAT , a voltage value which does not trigger the locking of the battery 1. Whereas if the output voltage of the storage stage 7 corresponds to the second voltage value V _A then this is lower than the reference voltage V _REF , and the output voltage is +V _SAT of the control stage 9. This voltage value +V _SAT is identified with the locking signal S _V and therefore triggers the locking of the battery 1 by the locking circuit.

It will be noted that the control stage 9 can also be configured so that the latching signal S _V corresponds to another voltage value, for example with an operational amplifier AO ₁ mounted as a non-inverting comparator, as long as the management system 3 is configured accordingly.

In other variant embodiments of the invention not shown, the device 5 does not comprise resistors R ₁ , R ₂ , R ₃ and/or R ₄ respectively forming a divider bridge at the input and output of the storage stage 7, for example because the input voltages V _UV , V _OV , V _T (and following) have voltage values compatible with the different electronic components of the device 5 or because a voltage step-down circuit is arranged upstream of said storage stage 7.

Claims (10)

Locking control device (5) for battery accumulator management system (3),
said device comprising at least:
– a stage (7) for storing abnormal operating conditions of the battery, said stage being configured, on the one hand, to receive as input one or more voltages (V _UV , V _OV , V _T ) relating to abnormal operating conditions, and on the other hand, to permanently store the occurrence of an abnormal operating condition of the battery;
– a locking control stage (9) whose input is connected to the output of said storage stage (7) and whose output is configured to be connected to said battery accumulator management system (3),
said control stage (7) being configured to send a locking command to said battery accumulator management system (9) if an abnormal operating condition is stored in said storage stage (7). Device (5) according to the preceding claim, characterized in that said storage stage (7) comprises a disconnection member (F ₁ ) configured to store an abnormal operating condition of the battery. Device (5) according to the preceding claim, characterized in that said disconnecting member (F ₁ ) is configured to permanently store an abnormal operating condition of the battery. Device (5) according to the preceding claim, characterized in that said disconnecting member (F ₁ ) is configured to disconnect if an input voltage (V _UV , V _OV , V _T ) of the storage stage (7) is greater than or equal to a predetermined value. Device (5) according to any one of the preceding claims, characterized in that said storage stage (7) comprises at least one switch (T ₁ ) configured to trigger the disconnection of said disconnection member (F ₁ ) as a function of the input voltage (V _UV , V _OV , V _T ) of said storage stage (7). Device (5) according to the preceding claim, characterized in that said at least one switch (T ₁ ) is a MOSFET type transistor. Device (5) according to any one of the preceding claims, characterized in that said storage stage (7) is configured to deliver as output:
– a first voltage value (V _N ) if the circuit breaker (F ₁ ) has not stored any abnormal operating condition;
– a second voltage value (V _A ) if the circuit breaker (F ₁ ) has stored an abnormal operating condition;
said control stage (9) being configured to send a locking command to said battery accumulator management system (3) if the control stage (9) receives the second voltage value (V _A ) as input. Device (5) according to any one of the preceding claims, characterized in that said control stage (9) comprises at least one operational amplifier (AO ₁ ) mounted as a comparator. Battery accumulator management system (3), characterized in that said system (3) comprises a locking control device (5) 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.