FR3132599A1 - MONITORING OF A PRECHARGE CIRCUIT OF A SYSTEM INTERFACE CIRCUIT - Google Patents

Abstract

A monitoring method is implemented in a system comprising a battery comprising first and second terminals and supplying electrical equipment via an interface circuit comprising a precharging circuit having an input terminal, connected to the first terminal, and an output terminal. This method comprises a step (10-60) in which, when the precharging circuit is used, the difference is determined between a first voltage measured between the first and second terminals and a second voltage measured between the output terminal and the second terminal or an intermediate terminal of the interface circuit temporarily coupled to the second terminal, and, when this difference is greater than a chosen threshold after expiry of a chosen duration, the use of the precharging circuit is interrupted in advance. Picture 3

Description

MONITORING A PRECHARGE CIRCUIT OF A SYSTEM INTERFACE CIRCUIT Technical field of the invention

The invention concerns systems comprising a battery supplying electrical energy to electrical equipment via an interface circuit, and more specifically the monitoring within such systems of a precharging circuit forming part of the interface circuit.

State of the art

Certain systems, such as for example certain vehicles (possibly of the automobile type), include a battery responsible for supplying electrical power to electrical equipment via an interface circuit comprising a precharging circuit. Note that when the system is a vehicle, its battery is sometimes called “main” (or traction) because it is responsible for supplying electric current to an electric motor of the powertrain (or GMP).

As those skilled in the art know, a precharging circuit is a sub-part of an interface circuit whose purpose is to limit the current coming from the battery before it powers one or more pieces of equipment. electric. For this purpose, a precharging circuit frequently includes a contactor (or switch) connected in series with a resistive component or a resistor offering significant electrical resistance (for example of the order of 500 Ohms in the case of a vehicle). As an illustrative example, when the battery is fully charged (and therefore has a maximum voltage at its terminals, for example between 350 V and 450 V) and the precharging circuit is used (or active), the current of precharge which circulates in the precharge circuit is very small, and therefore in all the electrical equipment concerned (that is to say powered "directly" by the battery) a voltage substantially equal to the aforementioned maximum voltage is established with this very small precharge current (typically < 1 A). This makes it possible to energize the power supply circuit of the electrical equipment concerned without creating a current peak which could damage their components and/or the components of the power supply circuit at the moment when the real power supply of at least one of this electrical equipment begins due to the placement in a closed state of at least one contactor (or switch) of the interface circuit. Indeed, when this contactor (or switch) is closed, if the power supply circuit has not been previously energized, a very significant current peak may occur in the latter for a very short period of time (possibly greater than 1000 A) which may damage electrical components located downstream. This very significant current peak should be compared to that which appears very briefly in practice when the contactor (or switch) of the precharging circuit is placed in its closed state to start the precharging function, and which is rarely greater than 20 A in a vehicle.

It will be understood that if an element of the precharging circuit does not work correctly, the precharging function cannot be ensured correctly, and therefore at the moment when the battery will begin to directly power at least one of the electrical equipment, it will have a high probability of damage to at least one of its electrical components and/or the power circuit.

The invention therefore aims in particular to monitor the precharging circuit in order to detect whether or not it has correctly performed its precharging function.

Presentation of the invention

It proposes in particular for this purpose a monitoring method intended to be implemented in a vehicle comprising a battery comprising first and second terminals and capable of supplying electrical power to electrical equipment via an interface circuit comprising a precharging circuit having an input terminal, connected to the first terminal, and an output terminal.

This monitoring method is characterized by the fact that it comprises a step in which, when the precharging circuit is used, a difference is determined between a first voltage measured between the first and second terminals and a second voltage measured between the terminal of output and the second terminal or an intermediate terminal of the interface circuit temporarily coupled to the second terminal, and, when this difference is greater than a chosen threshold after expiration of a chosen duration, the use of the circuit is interrupted in advance preload (because it did not achieve its objective).

Thus, we can now detect whether the precharging operation is taking place correctly, which makes it possible to decide without risk whether or not to authorize the power supply of at least one piece of electrical equipment via the interface circuit.

The monitoring method according to the invention may include other characteristics which can be taken separately or in combination, and in particular:

- in its step, when the difference is greater than the chosen threshold after the expiration of the chosen duration, the intermediate terminal of the interface circuit can be decoupled from the second terminal;

- in its stage, when the battery is rechargeable and in a recharge phase via an external power source coupled to the interface circuit, at least one current setpoint, less than one, can be transmitted to the external power source previous current setpoint, so that it provides a reduced recharge current, before interrupting the use of the precharge circuit in advance;

- in the presence of the last option, in its step we can transmit to the external power source a zero current reference, before interrupting in advance the use of the precharging circuit;

- in its stage, when the battery must participate in a phase of supplying at least one of the electrical equipment with an electrical power defined by a power setpoint, this power setpoint can be reduced, before interrupting in a manner anticipated use of the precharge circuit;

- in the presence of the last option, in its step we can immediately reduce the power setpoint to zero, before interrupting in advance the use of the precharging circuit;

- in its stage, in the event of early interruption of the use of the precharging circuit, at least one fault code representative of a detected precharging problem can be recorded in at least one memory of the system.

The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a monitoring method of the type of that presented above to monitor a precharging circuit forming part of an interface circuit installed between a battery and electrical equipment of a system, the battery comprising first and second terminals and being capable of supplying electrical power to this electrical equipment.

The invention also proposes a monitoring device intended to equip a system comprising a battery comprising first and second terminals and capable of supplying electrical power to electrical equipment via an interface circuit comprising a precharging circuit having an input terminal , connected to this first terminal, and an output terminal.

This monitoring device is characterized in that it comprises at least one processor and at least one memory arranged to perform the operations consisting, when the precharging circuit is used, of determining a difference between a first voltage measured between the first and second terminals and a second voltage measured between the output terminal and the second terminal or an intermediate terminal of the interface circuit temporarily coupled to the second terminal, and, when this difference is greater than a chosen threshold after expiration of a chosen duration , to trigger an early interruption of the use of the precharging circuit.

The invention also proposes a system comprising a battery comprising first and second terminals and capable of supplying electrical power to electrical equipment via an interface circuit comprising a precharging circuit having an input terminal, connected to this first terminal, and an output terminal, and a monitoring device of the type presented above.

For example, this system can be a vehicle, possibly of the automobile type.

Brief description of the figures

Other characteristics and advantages of the invention will appear on examination of the detailed description below, and the appended drawings, in which:

schematically and functionally illustrates an exemplary embodiment of a vehicle comprising a GMP, with an electric motor powered by a rechargeable main battery via an interface circuit with a precharging circuit, and a monitoring device according to the invention,

schematically and functionally illustrates an exemplary embodiment of a battery box, coupled to a main rechargeable battery and comprising an exemplary embodiment of a battery calculator comprising a monitoring device according to the invention, and

schematically illustrates an example of an algorithm implementing a monitoring method according to the invention.

Detailed description of the invention

The invention aims in particular to propose a monitoring method, and an associated DS monitoring device, intended to allow the monitoring of a CPC precharging circuit forming part of an interface circuit CI installed between a BP battery and MME and CH electrical equipment of an S system.

In what follows, we consider, by way of non-limiting example, that the system S is an automobile type vehicle. This is for example a car, as illustrated in the . But the invention is not limited to this type of system. It concerns in fact any type of system comprising a battery supplying electrical energy to electrical equipment via an interface circuit comprising a precharging circuit. Thus, it concerns, for example, land vehicles (utility vehicles, motorhomes, minibuses, coaches, trucks, motorcycles, road machinery, construction machinery, agricultural machinery, leisure machinery (snowmobile, kart), and road machinery. caterpillar(s), for example), boats and aircraft.

Furthermore, we consider in what follows, by way of non-limiting example, that the system S (here a vehicle) comprises a powertrain (or GMP) of all-electric type (and therefore whose traction is ensured exclusively by at least least one electric driving machine MME). But the GMP could be of hybrid type (thermal and electric).

We have schematically represented on the a system S (here a vehicle) comprising an electric GMP transmission chain, an on-board network RB, a utility battery BS, a (main) battery BP, a CV converter, and a monitoring device DS according to the invention .

The on-board network RB is an electrical supply network to which electrical (or electronic) equipment (or components) are coupled which consume electrical energy, for example very low voltage (typically 12 V, 24 V or 48 V). .

The BS utility battery is responsible for supplying electrical energy to the RB on-board network, in addition to that supplied by the CV converter powered by the BP battery, and sometimes in place of this CV converter (in particular when the GMP is asleep and the GE electrical energy generator inactive). For example, this BS utility battery can be arranged in the form of a very low voltage type battery (typically 12 V, 24 V or 48 V). It is rechargeable at least through the CV converter. We consider in the following, by way of non-limiting example, that the BS utility battery is of the 12 V Lithium-ion type.

The transmission chain has a GMP which is, here, purely electric, and therefore which includes, in particular, an electric driving machine MME, an AM motor shaft, and an AT transmission shaft. Here we mean “electric driving machine” an electric machine arranged so as to provide or recover torque to move the system S (here a vehicle). The operation of the GMP is supervised by a CS supervision computer.

The electric driving machine MME (here an electric motor) is coupled to the BP battery, in order to be supplied with electrical energy, as well as possibly to supply this BP battery with electrical energy during a regenerative braking phase. It is coupled to the AM motor shaft, to provide it with torque to drive it in rotation. This motor shaft AM is here coupled to a reduction gear RD which is also coupled to the transmission shaft AT, itself coupled to a first train T1 (here of wheels), preferably via a differential D1.

This first train T1 is here located in the front part PVV of the vehicle S. But in a variant this first train T1 could be the one which is here referenced T2 and which is located in the rear part PRV of the vehicle S.

The electric driving machine MME is, here, also coupled to the CV converter which is also indirectly coupled to the utility battery BS, in particular to recharge it with electrical energy from the BP battery and converted.

This CV converter is electrically coupled to the CN charging connector of vehicle S, for example. It is here also responsible for supplying the on-board network RB with electrical energy from the battery BP and converted when the GMP is in operation or when the GMP is asleep but the vehicle S is in a recharging phase of its battery BP , in addition to ensuring the recharging of the BS service battery.

The battery BP is hereinafter called the main (or traction) battery because it is notably responsible for supplying electrical power (or energy) to the electric motive machine MME to move the vehicle S..

For example, this main BP battery may include electrochemical cells for storing electrical energy, possibly of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type.

Also for example, the main BP battery can be of the low voltage type (typically 450 V for illustration purposes). But it could be medium voltage or high voltage.

As illustrated on the , this main battery BP notably comprises first b1 and second b2 terminals placed respectively at potentials U1 and U00.

Furthermore, in the example illustrated non-limitingly on the the main BP battery is rechargeable not only in mode 2 or 3, but also in mode 4. It is recalled that in a recharge in mode 2 or 3 the CV converter supplies the main BP battery with a direct current, after an AC/AC conversion. DC (“Alternative Current / Direct Current”, for example from 220 V to 450 V) of a charging current which is supplied by an external power source SA temporarily coupled to a charging connector CN of the vehicle S via a cable CR recharge.

It is also recalled that in mode 4 recharging, the main BP battery is supplied “directly” with high, continuous recharging current (typically between 100 A and 400 A) at a low input voltage (typically 450 V) by an external power source SA temporarily coupled to a charging connector CN of the vehicle S via a charging cable CR (and therefore without conversion by the CV converter).

Note, as illustrated non-limitatively in the , that the CV converter can be part of a CH charger charged within its vehicle S to control the charging of the main battery BP and electrically connected to the charging connector CN.

The CV converter is also responsible during the driving phases of the vehicle S of converting part of the electric current stored in the main battery BP to supply converted electric current, on the one hand, to the on-board network RB, and, on the other hand on the other hand, the BS service battery (to recharge it). Furthermore, the CV converter notably comprises two terminals placed respectively at potentials U4 and U01.

It should also be noted that the main battery BP is associated with a battery box BB which notably includes an interface circuit CI, voltage/current measuring means (not illustrated), and a battery calculator CB. This main battery BP and its battery box BB constitute a battery pack.

The CI interface circuit is sometimes called a "high voltage power supply circuit" because it is installed between the main battery BP and the CV and MME electrical equipment which must be powered without conversion at the current battery voltage main BP, when a computer (for example the CS supervision computer) requests it. This interface circuit CI is arranged so as to isolate, if necessary, the main battery BP from the CV converter and/or the driving machine MME and/or the CN connector, and includes a precharge circuit CPC which is used to put in voltage the power supply circuit and the electrical equipment concerned CV and MME just before supplying electrical power to at least one of the latter to operate it.

For example, and as illustrated without limitation on the , this interface circuit CI can include protection fuses F2 and F3 and contactors (or switches) Kj, for example based on MOSFET(s), each of which can take an open (or non-conducting) state and a closed state (or passerby). In the example illustrated non-limitingly on the the interface circuit CI includes five contactors (or switches) K1 to K5 (j = 1 to 5).

The first contactor (or switch) K1 comprises an input terminal be connected to the first terminal b1 (positive and placed at the electrical potential U1) of the main battery BP and is connected in series with a precharging resistor R which comprises a terminal bs output placed at electrical potential U3 and coupled indirectly or directly to the positive terminals of the CV converter (U4) and MME driving machine (U3). This first contactor (or switch) K1 and the precharge resistor R constitute the aforementioned precharge circuit CPC.

The second contactor (or switch) K2 is here connected in parallel with the precharge circuit CPC (between the input terminals be and output terminal bs). It ensures the coupling/decoupling of the main BP battery to/from the CV converter and MME prime mover.

The third contactor (or switch) K3 is here connected to the second terminal b2 (negative and placed at the electrical potential U00) of the main battery BP and to an intermediate terminal b3 of the interface circuit CI which is connected to the negative terminals (U01 ) of the MME prime mover and the CV converter. It ensures the coupling/decoupling of the main BP battery to/from the MME prime mover and the CV converter.

The fourth contactor (or switch) K4 is here connected to the second contactor (or switch) K2 (via a fuse F3 (U3-U5)) and to the positive terminal (U6) of the charging connector CN. It ensures the coupling/decoupling of the main battery BP to/from the CN charging connector.

The fifth contactor (or switch) K5 is here connected, on the one hand, to the third contactor (or switch) K3 (U01) and to the negative terminal of the CV converter, and, on the other hand, to the negative terminal (U02 ) of the CN charging connector. It ensures the coupling/decoupling of the main battery BP to/from the CN charging connector.

In the presence of this arrangement of the CI interface circuit illustrated on the , when the supervision computer CS wants the CV converter or the electric motor machine MME to be supplied with electrical power by the main battery BP, it asks the battery computer CB to close the contactors (or switches) Kj concerned to power the circuit CI interface. The battery calculator CB then triggers the closing of the third contactor K3, which is without risk because the other contactors (or switch) Kj are open, then triggers the precharging of the interface circuit CI. To do this, it triggers the closing of the first contactor (or switch) K1 so that the current from the main battery BP can flow in the interface circuit CI and that the CV converter, the electric motor machine MME and the circuit CI interface is set to the voltage of the main battery BP (here between 350V and 450V depending on the charge level of the latter (BP)). If the interface circuit CI operates correctly, the current stabilizes in the interface circuit CI (typically at a little less than 1 A), and therefore the latter (CI) is said to be “energized”. The battery calculator CB then triggers the closing of the second contactor (or switch) K2, and the interface circuit CI being already under the voltage of the main battery BP (and therefore correctly polarized) there is no longer any risk of current peak when closing the fourth contactor (or switch) K4 and/or the fifth contactor (or switch) K5. Note that once the second contactor (or switch) K2 is closed, the first contactor (or switch) K1 is no longer useful because of the large resistance presented by the precharge resistor R which forces the current to pass only through the second contactor (or switch) K2. Consequently, a few milliseconds after closing the second contactor (or switch) K2, the battery computer CB triggers the opening of the first contactor (or switch) K1 (because in the event of a need to urgently open the second contactor (or switch) ) K2 to protect the interface circuit CI the current could continue to pass through the first contactor (or switch) K1 if the latter (K1) was still closed).

In the illustrated arrangement, the voltage/current measuring means determine in particular a first voltage U10 (difference between the potentials U1 and U00) which is the voltage between the first b1 and second b2 terminals of the main battery BP, a voltage U30 (difference between potentials U3 and U00 when the third contactor (or switch) K3 is closed), and a voltage U31 (difference between potentials U3 and U01).

The CB battery calculator centralizes voltage and current measurements and determines current parameters of the main battery BP based on these measurements, and in particular its internal resistance, its minimum voltage, its state of charge (or SOC (“State Of Charge")) and his state of health (or SOH (“State Of Health")). Furthermore, the CB battery calculator exchanges information with the GMP CS supervision calculator and with the CC calculator associated with the CV converter (in particular for recharges in mode 4).

It will be noted that in the example illustrated non-limitingly on the the vehicle S also includes a distribution box BD to which the utility battery BS, the CV converter and the on-board network RB are coupled. This BD distribution box is responsible for distributing in the RB on-board network the electrical energy produced by the CV converter or stored in the BS utility battery, for powering the coupled electrical components (or equipment) (very low voltage). to the RB on-board network (and in particular the CB battery computer), depending on power requests received (in particular from the GMP CS supervision computer).

As mentioned above, the invention proposes in particular a monitoring method intended to allow monitoring of the CPC precharging circuit of the vehicle S.

This (monitoring) method can be implemented at least partially by the monitoring device DS (illustrated in Figures 1 and 2) which comprises for this purpose at least one processor PR1, for example a digital signal (or DSP ("DSP") Digital Signal Processor")), and at least one MD memory. This DS monitoring device can therefore be produced in the form of a combination of electrical or electronic circuits or components (or “hardware”) and software modules (or “software”). For example, it can be a microcontroller.

The memory MD is RAM in order to store instructions for the implementation by the processor PR1 of at least part of the monitoring process. The processor PR1 may include integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or non-wired connections. By integrated (or printed) circuit we mean any type of device capable of performing at least one electrical or electronic operation.

In the example illustrated without limitation in Figures 1 and 2, the monitoring device DS is part of the battery calculator CB (and therefore of the battery box BB). But this is not obligatory. Indeed, the monitoring device DS could include its own dedicated computer, which is then coupled to the battery computer CB.

As illustrated without limitation on the , the (monitoring) method, according to the invention, comprises a step 10-60 which is implemented in the vehicle S as soon as the precharging circuit CPC must be used, for example at the request of the battery calculator CB.

This step 10-60 includes a sub-step 10 in which (the monitoring device DS) begins by determining a difference dv between the first voltage U10 (measured between the first b1 and second b2 terminals of the main battery BP) and a second voltage measured between the output terminal bs of the precharge circuit CPC and the second terminal b2 (i.e. U30) or an intermediate terminal b3 of the interface circuit CI temporarily coupled (here via K3) to the second terminal b2 (i.e. U31) . Depending on the implementation chosen, we therefore have dv = U10 – U30 or dv = U10 – U31.

This step 10-60 also includes a sub-step 40 in which the use of the precharge circuit CPC is interrupted (the monitoring device DS triggers the interruption of) in advance when the difference dv is greater than a chosen threshold s1 (i.e. dv > s1) after expiration of a chosen duration dc, because it has not achieved its objective.

To do this, and as illustrated non-limitingly on the , step 10-60 may include a sub-step 20 in which (the monitoring device DS) compares the difference dv to the threshold s1. If the difference dv is less than or equal to the threshold s1 (i.e. dv ≤ s1) at the latest at the expiration of the chosen duration dc, we (the monitoring device DS) can, in a sub-step 30 of step 10-60, send a message to the battery calculator CB in order to inform it of the fact that the precharge function has taken place correctly (because the interface circuit CI has been substantially placed at the voltage of the main battery BP ( dv ≤ s1)). As indicated above, the battery calculator CB can then trigger the closing of the second contactor (or switch) K2. On the other hand, if the difference dv is greater than the threshold s1 (i.e. dv > s1) after expiration of the chosen duration dc, we (the monitoring device DS) sends in substep 40 another message to the battery calculator CB in order to to inform him of the fact that the precharge function did not take place correctly (because the interface circuit CI was not placed substantially at the voltage of the main battery BP (dv > s1)). The CB battery computer then knows that it must trigger the opening of the first contactor (or switch) K1, but that it must certainly not trigger the closing of the second contactor (or switch) K2.

Thanks to the monitoring of the CPC precharge circuit when it is used, we can detect whether the precharge operation is taking place correctly and therefore we can decide without risk whether or not to authorize the power supply of at least one piece of electrical equipment via the CI interface circuit.

It will be understood that it is at least the processor PR1 and memory MD of the monitoring device DS which are arranged to carry out the operations consisting, when the precharge circuit CPC is used, of determining the difference dv, and, when this difference dv is greater at the chosen threshold s1 after expiration of the chosen duration dc, to trigger the early interruption of the use of the CPC precharge circuit.

For example, the value of threshold s1 can be between 5 V and 15 V. As an illustrative example, the value of threshold s1 can be equal to 10 V.

Also for example, the value of the chosen duration dc can be between 0.5 s and 3 s. As an illustrative example, the value of the chosen duration dc can be equal to 1.5 s.

Note that in order to reduce the time necessary for the start of the effective supply of electrical power by the main battery BP in the absence of a precharging problem, it is possible to detect the instant id where the difference dv becomes less than the threshold s1. Thus, as soon as this detection is carried out, sub-step 30 can be carried out, without waiting for the chosen duration dc to have elapsed.

It will be noted that step 10-60 can also include a sub-step 50 in which, when the difference dv is greater than the threshold s1 chosen after the expiration of the chosen duration dc, we decouple (the monitoring device DS triggers the decoupling of) the intermediate terminal b3 of the interface circuit CI from the second terminal b2. In the presence of the arrangement of the IC interface circuit illustrated in the , this decoupling is done by placing the third contactor (or switch) K3 in its open state, for safety.

The opening of the first K1 and third K3 contactors (or switches) can possibly take place in two phases. In a first phase, the DS monitoring device can trigger the transmission to the GMP CS supervision computer of a request for authorization to open the first K1 and third K3 contactors (or switches). This transmission is provided here by the CB battery calculator. Then, if after a chosen time interval the DS monitoring device has not received a response to its authorization request, it can trigger in a second phase, on its own initiative, the opening of the first K1 and third K3 contactors (or switches) to electrically isolate the main battery BP from the interface circuit CI.

For example, this time interval can be between 1 s and 3 s. As an illustrative example, this time interval can be equal to 2 s. But other time interval values can be used (possibly variable depending on whether we are in a recharging phase or an electrical power supply phase by the main BP battery).

It will also be noted that when the main battery BP is rechargeable and in a recharge phase via an external power source SA coupled to the interface circuit CI via the connector CN, in sub-step 40 of step 10-60 , we can transmit (the monitoring device DS can trigger the transmission) to the external power source SA at (at) least one current setpoint which is lower than the previous current setpoint, so that it provides a reduced charging current, before interrupting early the use of the CPC precharging circuit.

It is recalled that at the start of a recharging phase an initial current setpoint cci is generated so that the external power source SA supplies the vehicle S (to which it is temporarily coupled) with an initial recharging current cri under a voltage nominal. Consequently, the (each) current setpoint which is transmitted in the event of detection of a precharging problem during a recharging phase is lower than the initial current setpoint cci, so that the recharging current becomes lower than the charging current. initial recharge cry, for security purposes.

In the presence of the last option, in sub-step 40 of step 10-60, it is possible to transmit (the monitoring device DS can trigger the transmission) to the external power source SA one (of) a setpoint zero current, before interrupting early the use of the CPC precharge circuit. In this case, the recharging phase is immediately interrupted. But in a variant embodiment it could be transmitted in a time interval new successive current instructions, increasingly smaller, up to a zero current instruction, so that the external power source SA successively supplies new currents charging which gradually decreases from the initial charging current cri to zero charging current.

It will also be noted that when the battery BP must participate in a phase of supplying at least one of the electrical equipment MME and CV via the interface circuit CI with an electrical power defined by a power setpoint, in the sub- step 40 of step 10-60 it is possible to reduce (the monitoring device DS can trigger the reduction of) this power setpoint, before interrupting in advance the use of the precharge circuit CPC.

It is recalled that the precharge is decided after an electrical power supply phase has been decided (for example by the supervision computer CS), and therefore after an initial power setpoint cpi has been generated for the control computer. CB battery. Consequently, the (each) power setpoint which is transmitted to the battery calculator CB in the event of detection of a precharging problem just before the actual supply of electrical power, is lower than the initial power setpoint cpi, in a security purpose.

In the presence of the last option, in substep 40 of step 10-60, it is possible to immediately reduce to zero (the monitoring device DS can trigger the immediate reduction to zero of) the initial power setpoint cpi, before to interrupt early the use of the CPC precharge circuit. In this case, the electrical power supply phase is immediately interrupted before the supply has actually started. But in a variant embodiment, new successive power instructions, increasingly smaller, could be transmitted in a time interval, down to a zero power instruction.

It will also be noted that step 10-60 can also include a sub-step 60 in which, in the event of an anticipated interruption of the use of the precharge circuit CPC, it is possible to record (the monitoring device DS can trigger the recording) in at least one memory of the system S with (at) least one fault code which is representative of a detected precharge problem.

Recording the fault code allows an after-sales service to determine the origin of the precharging problem detected (first contactor (or switch) K1 and/or precharging resistor R), and to inform the user of the vehicle S of the determined origin of the preload problem.

For example, after each detection of a precharging problem, a first fault code can be stored in a memory (possibly dead) of the battery calculator CB, and the supervision calculator CS observing the storage of this first fault code can possibly at its in turn store a second fault code in a (possibly dead) memory that it understands.

It will also be noted that in this sub-step 60 it is possible to alert a (the monitoring device DS can trigger the alert of a) user of the vehicle S, for example by means of a simple indicator light (possibly "stop") lit and/or a message (possibly dedicated to the precharging problem detected) which is displayed on at least one screen of the vehicle S (for example the dashboard) or on the screen of a smart phone (or “smartphone ") of the user, and/or broadcast by at least one speaker of the vehicle S or this smartphone.

Note also, as illustrated non-limitatively in the , that the CB battery calculator (or the dedicated calculator of the DS monitoring device) can also include a mass memory MM1, in particular for the temporary storage of the values of the first U10 and second U30 or U31 voltages and any intervening intermediate data in all its calculations and processing. Furthermore, this CB battery calculator (or the dedicated calculator of the DS monitoring device) can also include an IE input interface for receiving a message signaling the start of a precharge and at least the values of the first U10 and second U30 or U31 voltages to use them in calculations or processing, possibly after having shaped them and/or demodulated and/or amplified them, in a manner known per se, by means of a digital signal processor PR2. In addition, this CB battery calculator (or the dedicated calculator of the DS monitoring device) can also include an IS output interface, in particular to deliver orders or requests for opening of contactor(s) (or switch(es)) Kj, or messages containing new current or electrical power instructions, or possible messages containing fault codes, or even possible alert messages.

It will also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when executed by processing means of the electronic circuit (or hardware) type, such as for example the processor PR1, is capable of implementing the monitoring method described above to monitor in the system S the precharge circuit CPC which is part of the interface circuit CI installed between the battery BP and electrical equipment CV and MME .

Claims (10)

Monitoring method for a system (S) comprising a battery (BP) comprising first (b1) and second (b2) terminals and capable of supplying electrical power to electrical equipment via an interface circuit (CI) comprising a monitoring circuit precharge (CPC) having an input terminal (be), connected to said first terminal (b1), and an output terminal (bs), characterized in that it comprises a step (10-60) in which, when said precharge circuit (CPC) is used, a difference is determined between a first voltage measured between said first (b1) and second (b2) terminals and a second voltage measured between said output terminal (bs) and said second terminal (b2 ) or an intermediate terminal (b3) of said interface circuit (CI) temporarily coupled to said second terminal (b2), and, when said difference is greater than a chosen threshold after expiration of a chosen duration, we interrupt early the use of said precharge circuit (CPC). Method according to claim 1, characterized in that in said step (10-60), when said difference is greater than said chosen threshold after the expiration of said chosen duration, said intermediate terminal (b3) is decoupled from the interface circuit ( CI) of said second terminal (b2). Method according to claim 1 or 2, characterized in that in said step (10-60), when said battery (BP) is rechargeable and in a recharge phase via an external power source (SA) coupled to said circuit interface (CI), at least one current setpoint, lower than a previous current setpoint, is transmitted to said external power source (SA) so that it provides a reduced recharge current, before interrupting in a manner anticipated the use of said precharging circuit (CPC). Method according to claim 3, characterized in that in said step (10-60) a zero current setpoint is transmitted to said external power source (SA), before interrupting in advance the use of said precharging circuit (CPC). Method according to claim 1 or 2, characterized in that in said step (10-60), when said battery (BP) must participate in a phase of supplying at least one of said electrical equipment with an electrical power defined by a power setpoint, said power setpoint is reduced, before interrupting in advance the use of said precharging circuit (CPC). Method according to claim 5, characterized in that in said step (10-60) said power setpoint is immediately reduced to zero, before interrupting in advance the use of said precharging circuit (CPC). Method according to one of claims 1 to 6, characterized in that in said step (10-60), in the event of early interruption of the use of said precharging circuit (CPC), at least one memory of said system (S) at least one fault code representative of a detected precharging problem. Computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing the monitoring method according to one of claims 1 to 7 to monitor a precharging circuit ( CPC) forming part of an interface circuit (CI) installed between a battery (BP) and electrical equipment of a system (S), said battery (BP) comprising first (b1) and second (b2) terminals and being suitable for supplying electrical power to said electrical equipment. Monitoring device (DS) for a system (S) comprising a battery (BP) comprising first (b1) and second (b2) terminals and capable of supplying electrical power to electrical equipment via an interface circuit (CI) comprising a precharge circuit (CPC) having an input terminal (be), connected to said first terminal (b1), and an output terminal (bs), characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to perform the operations consisting, when said precharging circuit (CPC) is used, of determining a difference between a first voltage measured between said first (b1) and second (b2) terminals and a second voltage measured between said output terminal (BS) and said second terminal (b2) or an intermediate terminal (b3) of said interface circuit (CI) temporarily coupled to said second terminal (b2), and, when said difference is greater than one chosen threshold after expiration of a chosen duration, to trigger an early interruption of the use of said precharging circuit (CPC). System (S) comprising a battery (BP) comprising first (b1) and second (b2) terminals and capable of supplying electrical power to electrical equipment via an interface circuit (CI) comprising a precharging circuit (CPC) having an input terminal (be), connected to said first terminal (b1), and an output terminal (bs), characterized in that it further comprises a monitoring device (DS) according to claim 9.