SIMPLIFIED ELECTRICAL SYSTEM FOR POWERING VEHICLE EQUIPMENT

Abstract

An electrical system (SE) equips a vehicle (V) comprising a supervision computer (CS) and an on-board network (RB) operating under a first voltage, and comprises: - a cellular battery (BC) controlled by a battery computer (CB) and comprising N cells (CE) delivering a second voltage strictly higher than the first voltage, with N > 3, - a converter (CV) connected to a first circuit (C1) coupled to the on-board network (RB), and converting the second voltage into a first voltage to supply the on-board network (RB), and - a second circuit (C2) connected to the first circuit (C1) and to a subset of M cells (CE), with M < N, supplying the first voltage to the supervision computer (CS) so that it wakes up the converter (CV) and the battery computer (CB) so that it causes a coupling of the cellular battery (BC) to the first circuit (C1). Figure 1

Description

Title of the invention: SIMPLIFIED ELECTRICAL SYSTEM FOR THE ELECTRICAL SUPPLY OF VEHICLE EQUIPMENT Technical field of the invention

[0001] The invention relates to electrical systems equipping vehicles and responsible for supplying electrical equipment of these vehicles. State of the art

[0002] Currently, certain vehicles, possibly of the automobile type, include:

[0003] - an on-board network operating under a first voltage and to which are coupled on-board electrical (or electronic) equipment (or components) which consume electrical energy,

[0004] - an electrical system comprising a cellular battery operating under a second voltage (strictly higher than the first voltage) and controlled by a battery calculator, a converter, and a service battery operating under the first voltage,

[0005] - a powertrain (or GMP) comprising at least one driving machine electrically capable of being supplied with electrical energy under the second voltage to produce engine torque, and

[0006] - a supervision computer, for example responsible for supervising at least the GMP.

[0007] The cellular battery comprises electrical energy storage cells (possibly electrochemical (for example of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type)), delivering the second voltage, in particular for the electric motor. For example, this cellular battery may be of the very low voltage type (typically 48 V) or low voltage (typically 450 V), or even high voltage (typically 800 V and more).

[0008] The converter is connected to a first circuit (of the electrical system) which is suitable for being coupled to the on-board network, and is suitable for being coupled to the cellular battery in order to convert the second voltage into a first voltage to supply the on-board network and the supervision computer.

[0009] The service battery is responsible for supplying electrical energy to the on-board network in addition to that supplied by the converter when the latter is woken up and powered by the cellular battery, for example to stabilize the voltage in the on-board network. The service battery is also responsible for supplying electrical energy to the on-board network instead of the converter, in particular when the supervision computer has been woken up (after a standby phase) to wake up at its the converter (sleeping) and the battery computer (sleeping) so that the latter causes a coupling of the cellular battery to the first circuit intended to allow the converter to supply the first voltage to the on-board network. The service battery is also sometimes responsible for serving as an electrical energy buffer while the vehicle is being brought to safety.

[0010] For example, this service battery can be arranged in the form of a very low voltage type battery (typically 12 V or 24 V). It is generally rechargeable at least by the converter.

[0011] A main disadvantage of this type of electrical system lies in the fact that its service battery may be faulty or too discharged to allow the power supply of the woken-up supervision computer, for example because the vehicle has not been used for a long time and / or the outside temperature is very cold. It will be understood that in the presence of such a fault or of a voltage that is too low, the service battery is no longer able to perform its functions, and in particular to power the supervision computer which is the only one able to wake up the converter and the battery computer so that the converter alone can power the on-board network with the electrical energy stored in the cellular battery and converted.

[0012] Furthermore, the presence of this service battery increases the overall cost of the electrical system and therefore of the vehicle.

[0013] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0014] It proposes in particular for this purpose an electrical system, on the one hand, suitable for equipping a vehicle comprising a supervision computer and an on-board network operating under a first voltage, and, on the other hand, comprising:

[0015] - a cellular battery controlled by a battery computer and comprising N cells delivering a second voltage strictly higher than the first voltage, and

[0016] - a converter connected to a first circuit suitable for being coupled to the network of on board, and suitable for being coupled to the cellular battery and, in the event of wake-up by the supervision computer, for converting the second voltage into the first voltage to supply the on-board network.

[0017] This electrical system is characterized by the fact that it also comprises a second circuit connected to the first circuit and to a subset of M cells of the cellular battery, with M < N, capable of supplying the first voltage to the supervision computer so that it wakes up the converter and the battery computer so that it causes a coupling of the cellular battery to the first circuit.

[0018] Thanks to the invention, it is now possible to supply (in particular) the su calculator provision with the first voltage it needs to operate normally, without a service battery in the vehicle, which prevents the vehicle from being unable to be woken up.

[0019] The electrical system according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0020] - its second circuit may comprise a protection device comprising at least at least one protection diode and a current limiting device (such as a fuse) connected in series between, on the one hand, a first terminal of the subset of M cells, and, on the other hand, the first circuit to which the supervision computer is connected;

[0021] - in the presence of the first option, its second circuit may comprise a monitoring device comprising, on the one hand, a switch mounted in series between the first terminal and the protection device, and capable of being placed in a passing state or a non-passing state, and, on the other hand, a monitoring module capable of triggering a placement of the switch in its non-passing state when the first terminal has a voltage lower than a chosen threshold;

[0022] - as a variant and in the presence of the first option, its second circuit can include a monitoring device comprising, on the one hand, a switch mounted in series between a second terminal of the subset of M cells and a ground of the vehicle, and capable of being placed in a passing state or a non-passing state, and, on the other hand, a monitoring module capable of triggering a placement of the switch in its non-passing state when the first terminal has a voltage lower than a chosen threshold;

[0023] - its cell battery, battery calculator and converter can do part of a battery pack;

[0024] - in the presence of the last options and first sub-option, the battery pack can be connected to a vehicle ground;

[0025] - also in the presence of the last option or the last sub-option, its converter can be connected to a part of the first circuit, to which the second circuit is connected, and coupled to a third circuit connected to an output terminal of the battery assembly adapted to be coupled to a main terminal of the cellular battery, and to which electrical equipment of the vehicle is adapted to be connected;

[0026] - in the presence of the last sub-option, the battery assembly may comprise a interface device installed between, on the one hand, the main terminal of the cellular battery, and, on the other hand, the converter and the third circuit, and capable of being placed in a passing state or a non-passing state by the battery computer depending on whether the converter and / or the third circuit must be powered or not powered by the cell battery.

[0027] The invention also proposes a vehicle, possibly of the automobile type, and comprising a supervision computer, an on-board network operating under a first voltage, and an electrical system of the type presented above and coupled to the supervision computers and on-board network. Brief description of the figures

[0028] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0029] [Fig.l] schematically and functionally illustrates an example of a vehicle comprising a GMP with an electric motor coupled to a first example of an embodiment of an electrical system according to the invention to which are also coupled a GMP supervision computer and an on-board network,

[0030] [Fig.2] schematically and functionally illustrates an example of a vehicle comprising a GMP with an electric motor coupled to a second example of an embodiment of an electrical system according to the invention to which a GMP supervision computer and an on-board network are also coupled, and

[0031] [Fig.3] schematically and functionally illustrates an example of a vehicle comprising a GMP with an electric motor coupled to a third example of an embodiment of an electrical system according to the invention to which a GMP supervision computer and an on-board network are also coupled. Detailed description of the invention

[0032] The invention aims in particular to propose an electrical system SE comprising a cellular battery BC but no service battery, and intended to equip a vehicle V.

[0033] In the following, it is considered, by way of non-limiting example, that the vehicle V is of the automobile type. It is for example a car. But the invention is not limited to this type of vehicle. It relates in fact to any type of vehicle which must comprise an electrical system with a cellular battery to electrically supply electrical (or electronic) equipment (or components), possibly of high power. Thus, it relates to land vehicles (utility vehicles, camper vans, minibuses, coaches, trucks, motorcycles, road machinery, construction machinery, agricultural machinery, leisure machinery (snowmobile, kart), tracked vehicles, trains and trams, for example), aircraft and boats.

[0034] Furthermore, it is considered in the following, by way of non-limiting example, that the vehicle V comprises a transmission chain with a powertrain (or GMP) of the all-electric type (and therefore whose drive is provided exclusively by at least one electric motor MME). But the GMP could be of the type hybrid (thermal and electric).

[0035] It will be noted that the electrical system SE, according to the invention, is not necessarily intended to power an electric motor of a GMP. Indeed, it could power components operating under the second voltage u2 described later, such as for example high-power actuators.

[0036] Figures 1 to 3 schematically and functionally represent a vehicle V comprising an electric GMP transmission chain (and therefore an electric motor MME), a supervision computer CS, an on-board network RB, and an electrical system SE according to the invention, comprising a cellular battery BC, associated with an interface device DI and a battery computer CB, and a converter CV.

[0037] The on-board network RB is an electrical power supply network operating at a first voltage ul and to which electrical (or electronic) equipment (or components) are coupled which consume electrical energy at this first voltage ul, and in particular the battery computer CB.

[0038] The supervision computer CS operates under the first voltage ul and is here responsible for supervising the operation of the GMP (and therefore of the electric motor MME), as well as waking up, when they are asleep, the converter CV and the battery computer CB when it has itself been woken up (after a standby phase). It will be noted that the waking up of the supervision computer CS can result from the actuation of the ignition key (possibly electronic) (or any other starting control member) of the vehicle V, or from the triggering of the light warning function (or "waming") of the vehicle V, or even from the coupling of the vehicle V to an external power source to recharge the cellular battery BC, for example.

[0039] The electrical system SE comprises at least the cellular battery BC associated with the battery calculator CB, the converter CV, and first Cl and second C2 (electrical) circuits.

[0040] The cellular battery BC is controlled by the battery computer CB (when it is awake) and comprises N cells CE delivering a second voltage u2 which is strictly higher than the first voltage ul. The number N of cells CE is higher than three (i.e. N > 3). The cellular battery BC here supplies the electric motor MME, it constitutes a main battery (or “traction” or even “power”). These cells CE can, for example, be electrochemical (for example of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type). Also for example, the cellular battery BC can be of the very low voltage type (typically 48 V). But it could be of the low voltage type (typically 450 V) or medium voltage or even high voltage. This in fact depends on the value of the second voltage u2 which is needed here, in particular, by the electric motor MME to produce engine torque.

[0041] The cellular battery BC can be recharged via an external power source and temporarily coupled to the vehicle V, for example via a charging connector of the latter (V), and / or by torque recovery in the transmission chain (comprising the GMP), for example in a regenerative braking phase.

[0042] The first circuit Cl is suitable for being coupled to the on-board network RB so that it is supplied with the first voltage ul.

[0043] The CV converter is connected to the first circuit C1, suitable for being coupled to the cellular battery BC, and of the DC / DC (“Direct Current / Direct Current” type). In addition, this CV converter is suitable, when it is woken up by the supervision computer CS, for converting a direct current from the second voltage u2 (supplied by the cellular battery BC) to the first voltage ul to supply the on-board network RB.

[0044] In the example illustrated non-limitingly in [Fig.l] the CV converter is part of a CH charger which also includes a CA charger calculator responsible, at least, for controlling the recharges of the cellular battery BC, and which is woken up by the CS supervision calculator as soon as a recharge must be carried out. But the CV converter could be completely dissociated from the possible charger.

[0045] It will also be noted that in the examples illustrated non-limitingly in Figures 1 to 3, the converter CV is capable of being coupled to the cellular battery BC by an interface device DI which is installed between, on the one hand, a main terminal BP of the cellular battery BC, and, on the other hand, the converter CV and a third circuit C3 of the electrical system SE to which at least the electric motor MME is connected. This interface device DI is capable of being placed in a passing (or closed) state or a non-passing (or open) state by the battery computer CB depending on whether the converter CV and / or the third circuit C3 must be powered or not powered by the cellular battery BC. For this purpose, the interface device DI may, for example, comprise contactors (or switches or power relays), possibly based on MOSFET(s), as well as protective fuses.

[0046] The second circuit C2 is connected to the first circuit C1 and to a subset SEC of M cells CE of the cellular battery BC. The number M of cells CE of the subset SEC is less than the number N (i.e. M < N). This subset SEC is capable of supplying the first voltage ul to the supervision computer CS so that it wakes up the converter CV and the battery computer CB so that the latter (CB) causes the coupling of the cellular battery BC to the first circuit C1 (here by controlling the interface device DI).

[0047] It will be understood that this number M depends on the value of the first voltage ul of which need here, in particular, the on-board network RB and the supervision calculator CS and battery calculator CB to operate, and the type of cells CE. For example, and as illustrated non-limitingly in figures 1 to 3, when the first voltage ul is equal to 48 V and the cells CE are of the lithium-ion type, the number M can be equal to four (4).

[0048] Thanks to this second circuit C2 coupled to the subassembly SEC of M cells CE, it is now possible to supply (in particular) the supervision computer CS with the first voltage ul which it needs to operate normally (once woken up), and therefore to wake up in turn the converter CV and the battery computer CB. The latter (CB) can thus cause the interface device DI to be placed in its on-state so that the converter CV can start supplying the on-board network RB in place of the second circuit C2. This very advantageously makes it possible to no longer have to provide a service battery in the vehicle V, and therefore to avoid the vehicle V not being able to be woken up.

[0049] It will be noted that this second circuit C2 can also, when the vehicle V is awake, and for example in a rolling phase, supply electrical energy to the on-board network RB in addition to that supplied by the converter CV, for example to stabilize the voltage in the on-board network RB or to serve as an electrical energy buffer while the vehicle V is being made safe.

[0050] In other words, the second circuit C2 completely replaces the service battery, which allows for a simplified SE electrical system.

[0051] It will be noted that in the three embodiments illustrated non-limitingly in Figures 1 to 3 at least the cellular battery BC and the battery calculator CB of the electrical system SE are part of a battery assembly (or "pack") EB, and are therefore housed in a kind of protective and insulating housing. This battery assembly (or "pack") EB can also include the converter CV, as illustrated non-limitingly in Figures 2 and 3 (and as can also be the case in an alternative embodiment of the first example of [Fig.l]). But the protective and insulating housing could be dispensed with.

[0052] It will also be noted that in the first embodiment illustrated non-limitingly in [Fig.l] the electrical system SE also comprises a junction box BJ installed on the third circuit C3 between an output terminal BS of the battery assembly EB, suitable for being coupled to / decoupled from the main terminal BP of the cellular battery BC (here by means of the interface device DI), and the electrical equipment to be supplied with electrical energy at the second voltage u2 by the cellular battery BC. This electrical equipment is here at least the converter CV and the electric motor MME, as well as a possible heating / air conditioning installation (not shown). The junction box BJ is therefore in particular responsible for coupling each of the aforementioned electrical equipment to the third circuit C3 to ensure the distribution of electrical power, while ensuring electrical protection, for example by means of fuses. But it would be possible to do without the junction box BJ, as is the case in the second and third exemplary embodiments illustrated non-limitingly and respectively in figures 2 and 3.

[0053] It will also be noted, as illustrated non-limitingly in Figures 1 to 3, that the second circuit C2 may also comprise a protection device DPI comprising at least one protection diode DP2 and a current limiting device FP (such as for example a fuse) connected in series between, on the one hand, a first terminal B1 of the subset of M cells CE, and, on the other hand, the first circuit C1 (to which the supervision computer CS is connected). This protection device DPI is intended to avoid damaging the M cells CE of the subset SEC in the presence of excessively high currents.

[0054] It will also be noted, as illustrated non-limitingly in Figures 2 and 3, that the second circuit C2 can also comprise a monitoring device DS comprising a switch IS and a monitoring module MS.

[0055] In the second embodiment illustrated in [Fig. 2], the switch IS is connected in series between the first terminal B1 and the protection device DPI. This switch IS is capable of being placed in a conducting (or closed) state or a non-conducting (or open) state. The monitoring module MS is capable of triggering the placement of the switch IS in its non-conducting state when the first terminal B1 has a voltage which is lower than a chosen threshold. This arrangement is well suited to the case where it is the protection and insulation box of the battery assembly EB which is electrically connected to the electrical ground of the vehicle V.

[0056] In the third embodiment illustrated in [Fig. 3], the switch IS is connected in series between a second terminal B2 of the subassembly SEC of M cells CE and the electrical ground of the vehicle V to which the cellular battery BC is electrically connected (and not the protection and insulation box of the battery assembly EB). This switch IS is capable of being placed in a passing (or closed) state or a non-passing (or open) state. The monitoring module MS is capable of triggering the placing of the switch IS in its non-passing state when the first terminal B1 has a voltage which is lower than a chosen threshold.

[0057] It will be understood that in the second and third embodiments, the placement of the switch IS in its non-conducting state is intended to avoid discharging the M cells CE of the subassembly SEC, even though the voltage of the latter (SEC) is already very low (lower than the chosen threshold), to avoid damaging them irreversibly.

[0058] The threshold chosen depends on the value of the first voltage ul and the type of cells CE. For example, and as illustrated non-limitingly in FIGS. 1 to 3, when the first voltage ul is equal to 48 V and the cells CE are of the lithium-ion type, the threshold chosen may be equal to the number M of cells CE to power the on-board network RB multiplied by the minimum voltage of a cell CE when it is almost completely discharged. Thus, in the case of cells of the LFP (“Lithium Iron Phosphate”) type, the threshold chosen may, for example, be equal to 2.5 V x 4 = 10 V (when M is equal to four).

[0059] The monitoring module MS is completely autonomous, in order to be able to operate when the battery calculator CB has not yet been woken up by the supervision calculator CS. For this purpose, it can, for example, be implemented in wired logic.

[0060] The IS switch may, for example, comprise at least one contactor (or switch or power relay), possibly based on MOSFET(s). It will be noted that this IS switch is also preferably controlled by the CB computer once the latter (CB) has been woken up, as illustrated non-limitingly in Figures 2 and 3.

[0061] It will also be noted, as illustrated non-limitingly in Figures 2 and 3, that the CV converter can be connected to a part of the first circuit C1, to which the second circuit C2 is connected. In this case, the CV converter is coupled to the third circuit C3 (connected to the output terminal BS of the battery assembly EB and to which electrical equipment MME and CV of the vehicle V are suitable for being connected). This makes it possible to integrate the CV converter into the battery assembly EB.

Claims

Claims

1. Electrical system (SE) for a vehicle (V) comprising a supervision computer (CS) and an on-board network (RB) operating under a first voltage, said electrical system (SE) comprising i) a cellular battery (BC) controlled by a battery computer (CB) and comprising N cells (CE) delivering a second voltage strictly higher than said first voltage, with N > 3, and ii) a converter (CV) connected to a first circuit (Cl) capable of being coupled to said on-board network (RB), and capable of being coupled to said cellular battery (BC) and, in the event of wake-up by said supervision computer (CS), of converting said second voltage into a first voltage to supply said on-board network (RB), characterized in that it further comprises a second circuit (C2) connected to said first circuit (Cl) and to a subset of M cells (CE) of said cellular battery (BC), with M < N,suitable for supplying said first voltage to said supervision computer (CS) so that it wakes up said converter (CV) and said battery computer (CB) so that it causes coupling of said cellular battery (BC) to said first circuit (Cl).,

2. Electrical system according to claim 1, characterized in that said second circuit (C2) comprises a protection device (DPI) comprising at least one protection diode (DP2) and a current limiting device (FP) connected in series between, on the one hand, a first terminal (Bl) of said subset of M cells (CE), and, on the other hand, said first circuit (Cl) to which said supervision computer (CS) is connected.

3. Electrical system according to claim 2, characterized in that said second circuit (C2) comprises a monitoring device (DS) comprising a switch (IS) mounted in series between said first terminal (Bl) and said protection device (DPI), and capable of being placed in a passing state or a non-passing state, and ii) a monitoring module (MS) capable of triggering a placing of said switch (IS) in its non-passing state when said first terminal (Bl) has a voltage lower than a chosen threshold.

4. Electrical system according to claim 2, characterized in that said second circuit (C2) comprises a monitoring device (DS) comprising a switch (IS) mounted in series between a second terminal (B2) of said subset of M cells (CE) and a ground of said vehicle (V), and capable of being placed in a passing state or a non-passing state, and ii) a monitoring module (MS) capable of triggering a placement of said switch (IS) in its non-passing state when said first terminal (Bl) has a voltage lower than a chosen threshold.

5. Electrical system according to one of claims 1 to 4, characterized in that said cellular battery (BC), said battery calculator (CB) and said converter (CV) are part of a battery assembly (EB).

6. Electrical system according to the combination of claims 3 and 5, characterized in that said battery assembly (EB) is connected to a ground of said vehicle (V).

7. Electrical system according to claim 5 or 6 taken in combination with one of claims 2 to 4, characterized in that said converter (CV) is connected to a part of said first circuit (Cl), to which said second circuit (C2) is connected, and coupled to a third circuit (C3) connected to an output terminal (BS) of said battery assembly (EB) suitable for being coupled to a main terminal (BP) of said cellular battery (BC), and to which electrical equipment (MME) of said vehicle (V) is suitable for being connected.

8. Electrical system according to claim 5 or 6 taken in combination with claim 7, characterized in that said battery assembly (EB) comprises an interface device (DI) installed between, on the one hand, said main terminal (BP) of the cellular battery (BC), and, on the other hand, said converter (CV) and said third circuit (C3), and suitable for being placed in a passing state or a non-passing state by said battery computer (CB) depending on whether said converter (CV) and / or said third circuit (C3) must be powered or not powered by said cellular battery (BC).

9. Vehicle (V) comprising a supervision computer (CS) and an on-board network (RB) operating under a first voltage, characterized in that it further comprises an electrical system (SE) according to one of claims 1 to 8, coupled to said supervision computer (CS) and on-board network (RB).

10. Vehicle according to claim 9, characterized in that it is of the automobile type.

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