FR3096521A1 - VEHICLE ELECTRICAL NETWORK WITH VOLTAGE CONVERTER FOR AT LEAST ONE ELECTRICAL UNIT - Google Patents

Abstract

An electrical network (RE) equips a vehicle (V) and comprises, connected in parallel, a lithium-ion type battery (BA) delivering a first voltage and a branch (B1) comprising an electrical component (OE1) requiring at least temporarily a second voltage greater than the first voltage. The branch (B1) further comprises a converter (CV1) of the direct current / direct current type, mounted in series with the electrical unit (OE1), between the latter (OE1) and the battery (BA), and producing the second voltage required by the electric unit (OE1) from the first voltage supplied by the battery (BA) to supply the electric unit (OE1) with second voltage when this is required. Figure to be published with the abstract: Fig. 1

Description

Description Title of the invention: VEHICLE ELECTRIC NETWORK WITH A VOLTAGE CONVERTER FOR AT LEAST ONE ELECTRICAL COMPONENT Technical field of the invention 100011 The invention relates to vehicles, possibly of the automobile type, and more precisely to the electrical networks which equip these vehicles.

State of the art

[0002] Many vehicles include an electrical network comprising, connected in parallel, a lead-acid battery delivering a first voltage (for example equal to 12 V) and at least one branch comprising at least one electrical member requiring at least temporarily a second voltage greater than the first voltage.

For example, this electrical device can provide a lighting and / or signaling function, or cooling of a heat engine by ventilation, or wiping window (s), or spraying window washing liquid. , or electric steering control, or even trajectory control.

[0003] To temporarily reach this second voltage when it is the battery which must supply the electrical component, a boost (or “boost”) is carried out by means of an electrical energy management device.

The lead-acid battery responds to boosting easily and quickly, and adjusts its voltage to the second required voltage.

Thus, during a boost it can, for example, supply a second voltage between 12.3 V and 15.2 V (these values are purely illustrative).

When one wants to replace the lead-acid battery with a lithium-ion (or Li-ion) type battery, the latter is unable to provide certain second voltages to certain electrical components which require it, including in the presence of 'a boost.

Thus, some lithium-ion batteries cannot supply a voltage higher than 13.8 V (this value may vary depending on the technology of the battery and / or its capacity), and in addition has a relatively long inertia to respond boosting.

In this case, we are forced, when possible, to change the type of the electrical device so that it uses a smaller second voltage (typically less than 13.8 V).

For example, when the electrical device is a halogen bulb (or lamp) projector, it can be replaced by a light-emitting diode (or LEDs) projector.

However, such a replacement is not always possible, in particular when there is no other type of electrical device using a second voltage lower than that which the lithium-ion battery can provide, or when the cost of the other type of electric organ is too high.

This latter hypothesis corresponds 2 in particular to the case of the light-emitting diode headlamp, the price of which is significantly higher than that of a halogen bulb (or lamp) headlamp.

[0005] The aim of the invention is therefore in particular to improve the situation.

Presentation of the invention

[0006] For this purpose, it proposes in particular an electrical network intended to equip a vehicle and comprising, connected in parallel, a lithium-ion type battery delivering a first voltage and a branch comprising at least one electrical member requiring at least temporarily a second voltage greater than the first voltage.

This electrical network is characterized by the fact that it also comprises a converter of direct current / direct current type, mounted in series with the electrical member in the branch, between the last DC and the battery, and producing the second voltage required by the electrical device from the first voltage delivered by the battery to supply the electrical device with a second voltage when required.

Thanks to this converter in the branch which comprises one (s) electrical unit (s) requiring a second voltage higher than the first voltage that the lithium-ion battery can provide, we can easily provide this ( these) electrical device (s) their second voltage.

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

- The converter can, for example, have a power between 200 W and 800 W.

For example, this power can be equal to 400 W;

[0011] the branch may comprise at least one electrical member providing a lighting and / or signaling function;

- It may include at least one other branch comprising at least one other electrical member requiring at least temporarily a third voltage greater than the first voltage, and another converter of direct current / direct current type, mounted in series with the another electric member in the other branch, between the latter and the battery, and producing the third voltage required by the other electric member from the first voltage supplied by the battery to supply the other electric member with the third voltage when this is required.

The invention also provides a vehicle, optionally of the automotive type, and comprising an electrical network of the type of that presented above.

Brief description of figures 100141 Other characteristics and advantages of the invention will become apparent on examination of the detailed description below, and of the appended drawing, in which: 100151 I fie. 11 schematically and functionally illustrates an example of a vehicle comprising an exemplary embodiment of an electrical network according to the invention.

3 Detailed description of the invention

The object of the invention is in particular to provide an electrical network RE intended to equip a vehicle V and capable of supplying voltage to at least one electrical component 0E1 while it comprises a lithium-ion type battery BA delivering a insufficient voltage for the operation of the latter (0E1).

In what follows, it is considered, by way of nonlimiting example, that the electrical network RE is intended to equip a vehicle of the automotive type, such as for example a car.

But the invention is not limited to this type of vehicle.

In fact, it relates to any vehicle comprising electrical components requiring a voltage greater than that supplied by its battery.

Consequently, an RE electrical network can equip any type of vehicle (land, sea (or river), or air).

There is schematically shown in Figure I an example of vehicle V comprising an embodiment of an electrical network RE according to the invention.

As illustrated, an electrical network RE, according to the invention, comprises, connected in parallel, at least one battery BA, of lithium-ion type and delivering a first voltage vl, and a first branch BI, comprising at least one first electrical unit 0E1 and a first converter CV1 of direct current / direct current type (or DC / DC (“Direct Current / Direct Current”)).

Each first electrical member 0E1 of this first branch Bi requires at least temporarily a second voltage v2 which is greater than the first voltage vi.

For example, the first branch Bi comprises at least a first electrical member 0E1 providing a lighting and / or signaling function, such as for example a high beam or a low beam.

But a first electrical device 0E1 can perform any function by being supplied with a second voltage v2 greater than the first voltage v I.

Thus, it can, for example, provide a cooling function for a heat engine by ventilation (motor-fan unit (or GMV)), or wiping window (s) (electric wiper motors), or spraying window washing liquid (electric pump), or electric steering control (electric power steering), or even trajectory control (trajectory control device (for example of the ESC type ("Electronic Stability Control). "))).

The first converter CV1 is mounted in series with the (each) first electrical member 0E1 in the first branch Bi, between the latter (0E1) and the battery BA.

In addition, this first converter CV1 produces the second voltage v2, required by the (each) first electrical unit 0E1 from the first voltage v1 delivered by the battery BA to supply the (each) first electrical unit 0E1 with a second voltage v2 when this is required.

Thus, each first electrical member 0E1 of the first branch B1 can be supplied with the second voltage v2 which it needs to operate correctly and which is greater than the first voltage vl that the lithium-ion battery BA can provide, by virtue of the voltage conversion carried out by the first converter CV1 from the first voltage vl.

In addition, this eliminates the need for boosting (or boosts) with a DG electrical energy management device.

This last device is still useful to manage the tensions in other cases of life, but without the boosts.

The power of the first converter CV1 is chosen according to the first electrical members 0E1 to be supplied in the first branch Bi.

For example, when the first branch B1 is dedicated to the lighting and / or signaling of a motor vehicle, the first converter CV1 can have a power of between 200 W and 800 W.

Thus, this power can be equal to 400 W (or 2 "200 W).

But to ensure other functions, such as for example cooling by ventilation, the first converter CV1 can have a greater power (for example equal to 800 W).

As illustrated in Figure 1, in a vehicle V, the battery BA is only a temporary source of electrical power, and therefore the electrical network RE comprises a branch mounted in parallel with the battery BA and comprising a alternator AL and / or a DC / DC converter supplying the electric power supply and recharging the battery BA.

This branch is mounted between the battery BA and the first branch Bi.

Furthermore, and as illustrated in FIG. 1, in a vehicle V the electrical network RE comprises another branch mounted in parallel with the battery BA and comprising an on-board network RB grouping together all the electrical components which do not need a voltage greater than the first voltage vl.

It will be noted, as illustrated non-linearly in Figure 1, that the electrical network RE can also include at least one other (second) branch B2 comprising at least one other (second) electrical member 0E2 requiring at least temporarily a third voltage v3 greater than the first voltage v1, and another (second) converter CV2 of the direct current / direct current type.

In this case, the latter (CV2) is mounted in series with the other (second) electric unit 0E2 in the other (second) branch B2, between the latter (0E2) and the battery BA.

In addition, this second converter CV2 produces the third voltage v3, required by the (each) second electrical unit 0E2, from the second voltage v2 delivered by the battery BA to supply the (each) second electrical unit 0E2 with the third voltage v3 when required.

The power of the second converter CV2 is chosen according to the second electrical members 0E2 to be supplied in the second branch B2.

Furthermore, the third voltage v3 may be different from, or identical to, the second voltage v2.

For example, the second branch B2 comprises at least one second electrical member 0E2 providing an emergency avoidance function of an obstacle or automatic parking thanks to the electric power steering, or emergency braking by activation a trajectory control device (for example of the ESC type).

Although this does not appear in Figure 1, the electrical network RE could still include one or more other branches comprising one or more other electrical members requiring at least temporarily a voltage greater than the first voltage vl. 6

Claims (1)

CLAIMS [Claim I] Electrical network (RE) intended to equip a vehicle (V) and comprising, connected in parallel, a lithium-ion type battery (BA) delivering a first voltage and a branch (B1) comprising at least one member electric (0E1) requiring at least temporarily a second voltage greater than said first voltage, characterized in that it further comprises a converter (CV1) of direct current / direct current type, mounted in series with said electric member (0E1) in said branch (B1), between cc last (0E1) and said battery (BA), and producing said second voltage required by said electric unit (0E1) from said first voltage supplied by said battery (BA) to power said electric unit (0E1) in second voltage when required. [Claim 2] Electrical network according to claim 1, characterized in that said converter (CV1) has a power between 200 W and 800 W. [Claim 3] Electrical network according to claim 2, characterized in that said converter (CV1 ) has a power equal to 400 W. [Claim 4] Electrical network according to one of claims 1 to 3, characterized in that said branch (B1) comprises at least one electrical member (0E1) providing a lighting function and / or signaling. [Claim 5] An electrical network according to one of claims 1 to 4, characterized in that it comprises at least one other branch (B2) comprising at least one other electrical member (0E2) requiring at least temporarily a third voltage greater than said first voltage, and another converter (CV2) of direct current / direct current type, mounted in series with said other electrical member (0E2) in said other branch (B2), between the latter (0E2) and said battery (BA) , and producing said third voltage required by said other electric member (0E2) from said first voltage supplied by said battery (BA) to supply said other electric member (0E2) with a third voltage when required. [Claim 6] Vehicle (V), characterized in that it comprises an electrical network (RE) according to one of the preceding claims. [Claim 7] Vehicle according to claim 6, characterized in that it is of the automotive type.