Charging cable with optimized wire cross-section for charging an electric vehicle

Abstract

The invention relates to a charging cable (1) for charging an electric vehicle, the charging cable comprising at least five electrical conductors, including three phase conductors (L1, L2, L3) and one neutral conductor (N), the cable extending between a first end (E1) and a second end (E2), characterized in that the phase conductors have at least two different cross-sections, including a first cross-section and a second cross-section smaller than the first cross-section, and in that the first phase conductor (L1) has the first cross-section as its cross-section, the second phase conductors (L2) and the third phase conductors (L3) have the second cross-section as their cross-section, and the neutral conductor (N) has the first cross-section as its cross-section. Figure 2

Description

Title of the invention: CHARGING CABLE WITH OPTIMIZED WIRE SECTION FOR CHARGING AN ELECTRIC VEHICLE

[0001] The invention relates to a charging cable for charging electric vehicles.

[0002] Generally speaking, for various reasons, particularly ecological and climatological, we are seeing an increase in the number of electric and hybrid vehicles in circulation.

[0003] In this type of vehicle, it is necessary to recharge the batteries from time to time, otherwise called here means of storing electrical energy.

[0004] Charging is carried out from an electrical outlet available in the usual home of the vehicle user (so-called 'domestic' outlet) or from a charging station located in the public or semi-public domain.

[0005] To recharge electric and hybrid vehicles, it is necessary to use an electric charging cable intended to connect, on the one hand, a charging base on the vehicle side and, on the other hand, a power supply socket on the opposite side, namely the station side or the household electrical socket.

[0006] The case in which the electric charging cable is arranged in a housing of the electric vehicle, and permanently connected at one of its ends to a control box forming part of the vehicle, is considered here. Means are provided here for removing the cable from the housing to connect it to an external charging socket, for example either by means of a winding system or by means of an extensibility property of the cable. The plug / socket arranged at the other end can be grasped by a user, extracted and brought to the location of an ad-hoc external charging socket to be plugged in.

[0007] Charging a zero-emission vehicle, whose battery generally has a capacity of between 50 kWh and 100 kWh, requires a very long charging time from a standard power outlet delivering between 2 and 3 kW. This is why there is a trend towards being able to charge your electric vehicle at home at a higher power.

[0008] There is a trend among electric vehicle users to equip their homes with a powerful power line to supply the charging socket for their electric vehicle. The socket dedicated to charging the vehicle is then no longer a standard single-phase socket limited to around ten amps.

[0009] In this context, we can use a specific powerful line, and we install a box sometimes called a “Wallbox”, which can deliver to the vehicle, from the line specific, more than 20 amps, or even up to 32 amps, always in single-phase.

[0010] In fact, homes are equipped, with rare exceptions, with a power supply with a single phase (therefore in single-phase) and are very rarely equipped with a three-phase network supply.

[0011] Thanks to the large caliber line and the single-phase 'Wallbox', it is possible to deliver up to 7 kW for recharging the electric vehicle at home. It is not excluded to go beyond this in single-phase but this requires a very specific installation from the meter of the main electrical energy delivery point.

[0012] As for public charging stations, three-phase is very often available on new installations. Three-phase allows for so-called accelerated charging. Three-phase charging is most often available at a power level of 22 kW, which corresponds to amperages of 32 amps per conductor. Some public stations, although three-phase, have a power level of up to 11 kW, which corresponds to amperages of 16 amps per conductor.

[0013] There are also public terminals which only have a single-phase power supply, and then the power limit is 3.5 kW and 7 kW for respective amperages of 16A and 32A as for the domestic case.

[0014] Furthermore, each type of vehicle is characterized by a type of battery and an on-board charge controller which controls the charging current admissible by the vehicle battery. In particular, the on-board charge controller may have as a parameter the maximum admissible power for recharging the battery, this maximum admissible power takes into account the characteristics of the battery and the electrical distribution system which carries the current to the battery.

[0015] The current flowing in the charging cable, which connects the battery to the electrical power supply socket, must not cause excessive heating of said charging cable. The cross-sections of the conductors define a maximum permanent intensity rating, in some cases accompanied by a momentary peak intensity level.

[0016] There are several charging modes at public terminals. Thus, the power actually delivered depends on a transaction between the charge controller on board the vehicle and the controller of the external charging terminal.

[0017] The on-board charge controller controls the vehicle's charging mode to benefit from the greatest available power depending on the charging source, the maximum admissible power for the battery and the current routing circuits including the charging cable which allows the battery to be connected to the electrical power supply socket.

[0018] Thus, in certain cases, it is the charging cable used which is the weakest link in establishing the maximum possible charging power.

[0019] The inventors sought to propose an optimal solution for the charging cable on board the vehicle, in order to be able to make the most of the charging sources (domestic or public), while having the lowest possible weight and cable section.

[0020] For this purpose, the invention proposes a charging cable for charging an electric vehicle, the charging cable comprising at least five electrical conductors (or 'wires') including three phase conductors (L1, L2, L3) and a neutral conductor (N), the cable extending between a first end and a second end, characterized in that the phase conductors have at least two different cross-sections, including a first cross-section and a second cross-section smaller than the first cross-section, and in that the first phase conductor (L1) has as its cross-section the first cross-section and the second phase (L2) and third phase (L3) conductors have as its cross-section the second cross-section, and the neutral conductor (N) has as its cross-section the first cross-section.

[0021] Thanks to such an arrangement, we have the conductor sections just necessary for different charging configurations. In fact, for single-phase charging, the conductor of the first phase L1 and the neutral conductor N are used at their maximum caliber. For three-phase charging, the conductors of the second phase L2 and the third phase L3 are used at their maximum caliber, the conductor of the first phase L1 being able to be used a little below its caliber.

[0022] We note that it is counter-intuitive to have the conductors of the 3 phases not identical, this goes against the logic of classical engineering.

[0023] Advantageously, the weight and cross-section of the cable are thus the most optimal in relation to the maximum use of their capacity of the drivers. The bulk of the charging cable in the vehicle is thus minimal and the low weight of the charging cable does not affect the ecological performance of the vehicle.

[0024] In a non-limiting example, if the on-board charging controller and the on-board battery define a charging power limit of 11 kilowatts, in three-phase charging, the charging current is approximately 16 amps, whereas in single-phase charging at 7 kW, the charging current is approximately 32 amps, which requires larger sections on the first-phase conductor L1 and the neutral conductor N.

[0025] According to one embodiment, the charging cable may further comprise a protective conductor (PE) which has the first cross-section as its cross-section.

[0026] As a result, the earthing protection has a section as large as the phase to effectively route any possible leak directly towards the earth.

[0027] However, it is not excluded to have the protective conductor of a smaller section than the first cross-section.

[0028] According to one embodiment, the first cross-section is at least twice as large as the second cross-section.

[0029] This corresponds substantially to a current level twice as low for three-phase charging compared to single-phase charging.

[0030] According to one embodiment, the first cross-section may be 6 mm2 and the second cross-section may be 2.5 mm2.

[0031] According to one embodiment, the charging cable may further comprise a control conductor (CP) which has as a cross-section a third cross-section, smaller than the second cross-section.

[0032] On the control conductor, only weak currents pass through and therefore the section can be as small as possible, compatible however with the mechanical strength of the conductor.

[0033] According to one embodiment, the third cross-section may be 0.5 mm2.

[0034] According to one embodiment, the charging cable comprises six conductors.

[0035] This is just what is necessary. There is no seventh conductor and the so-called 'proximity' track remains conductorless.

[0036] According to one embodiment, the charging cable comprises at its first end a first plug of type 2 with 7 cells within the meaning of standard IEC62196.3.

[0037] Here type 2 is defined in relation to the IEC62196.3 standard which defines the seven standard electrical channels and their respective positions.

[0038] Thanks to this arrangement, the charging cable can be connected to public charging stations in France and in the majority of European countries.

[0039] According to one embodiment, a main portion of the cable between the first end and the second end has a helical shape, the charging cable thus being extensible. The charging cable is thus provided with a telescopic function, by means of traction. The charging cable is such that it has an intrinsic function of returning to its helical rest shape (also called 'spiral'), with a length in the helical shape 4 to 10 times smaller than the developed length.

[0040] According to one embodiment, the charging cable has a length of at least 5 meters in a deployed configuration. This makes it suitable for most charging situations, particularly on public roads, in order to be able to connect the plug to the terminal.

[0041] The present mention also relates to an assembly comprising a charging cable as described previously and an adapter comprising a first connector forming a counterpart of the first plug of the charging cable and a second connector configured to be plugged into a domestic socket type charging base (2P+T).

[0042] Advantageously, the adapter only relays three conductors.

[0043] According to one embodiment, the adapter in question can be equipped with a local control box. This box is the equivalent of the load control box usually found on single-phase cables.

[0044] The present mention also relates to a motor vehicle comprising a charging cable as described previously, the second end being connected to a control box configured to control charging modes of the vehicle in order to benefit from the greatest available power depending on the charging source.

[0045] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which: [Fig.l] is a schematic representation of a vehicle comprising a charging cable, of the helical type, received in a retracted position in a housing of a motor vehicle, [Fig.2] represents a functional schematic diagram of the charging cable and its annexes, in accordance with the present invention, [Fig.3] is a schematic representation of a vehicle being recharged at a public terminal, [Fig.4] is a cross-sectional view of the charging cable according to the present invention, [Fig.5] schematically represents the allocation of the channels in the type 2 socket, [Fig.6] is similar to [Fig.2] and shows a variant of the functional schematic diagram of the charging cable and its annexes, [Fig.7] schematically and graphically represents the currents and powers involved in two types of charging, single-phase and three-phase.

[0046] In the various figures, the same references designate identical or similar elements. For reasons of clarity of the description, certain elements are not necessarily represented to scale.

[0047] In [Fig.l], an electric vehicle 9 is shown comprising a charging cable 1. The charging cable 1 is extendable. In the example illustrated, the charging cable is of the helical type. The charging cable 1 is received in the retracted position in a housing 90.

[0048] The charging cable 1 extends between a first end E1 and a second end E2. The second end E2 of the cable is connected, via a second connector 12, to a control box 2 whose functions will be seen later.

[0049] The charging cable 1 comprises at its first end El a first plug 11 connection. This first plug 11 is in the example illustrated here a type 2 plug with 7 sockets, as defined in the IEC62196.3 standard.

[0050] The vehicle comprises a hollow space 4 for receiving the first plug. As known per se, a retractable hatch is provided for closing the hollow space 4 and hiding the first plug 11.

[0051] The charging cable 1 is stored in the housing 90 in a wound or retracted form. In use, the charging cable is in an extended configuration, it is unwound or deployed.

[0052] In this document, these are electric vehicles with electric propulsion or traction, for example 100% electric vehicles (zero emissions) or rechargeable hybrid vehicles. Depending on the type of vehicle, the electrical energy storage capacity of the battery can range from 10 kWh to 100 kWh, which has a major influence on the recharging time required for a given recharging power.

[0053] [Fig.2] represents a functional diagram of the charging cable 1 in the vehicle and with its environment, in particular with an adapter 3 which can be coupled to it and the use of which will be seen later.

[0054] The illustrated charging cable comprises six conductors. These six conductors comprise: - a neutral conductor N, - a first phase conductor Ll, - a second phase conductor L2, - a third phase conductor L3, - a protective conductor PE, - a control conductor CP.

[0055] The first phase conductor L1 and the neutral conductor N each have as a cross-section a first cross-section denoted SL. The second phase conductor L2 and the third phase conductor L3 each have as a cross-section a second cross-section denoted S2.

[0056] In the illustrated example, the first cross-section SI is 6 mm2, and the second cross-section S2 is 2.5 mm2.

[0057] More generally, the invention provides that the first cross-section S1 is larger than the second cross-section S2. According to a preferred example, the first cross-section S1 is at least twice as large as the second cross-section S2. Of course, the numerical values ​​of sections set out above are only indicative; other values ​​are entirely possible.

[0058] Concerning the cross sections, one can choose to respect the condition 2 x S2 <Sl<2,5xS2.

[0059] In the example illustrated, the PE protective conductor has the first cross-section SI as its cross-section. However, it may be otherwise. The PE protective conductor is not used in normal situations. It is used in the event of an unwanted current leakage to any chassis element, in which case the PE protective conductor carries the leakage to earth.

[0060] The control conductor CP has a third cross-section marked S3, which is smaller than the second cross-section. In the example illustrated, S3 is 0.5 mm2, but again other values ​​are possible. Generally, the third section is chosen for reasons of mechanical strength because when the charging cable is mechanically stressed, the conductor with the smallest section must not be damaged.

[0061] As can be seen in the section of [Fig.4], according to the example illustrated, the conductors of the first phase L1, neutral N, and earth PE respectively have the first section SL as their cross-section. The conductors of the second phase L2 and third phase L3 respectively have the second section S2 as their cross-section, the control conductor CP has the second third section S3 as their cross-section. The six conductors are surrounded by a protective sheath 18. A filling polymer may be provided between the conductors and the protective sheath. A core of mechanically resistant material may also be provided, which does not participate in the actual electrical connection.

[0062] According to a spiral or helical cable configuration, the charging cable 1 may comprise a number of turns between 15 and 35.

[0063] In order to be able to connect the charging cable to a 2P+T domestic socket, it is planned to add an adapter marked 3 to the charging cable itself.

[0064] The adapter 3 shown on the left in [Fig.2] allows a user to recharge his vehicle on a standard domestic power outlet called 2P+T. To do this, he must connect the first side of the adapter to the first plug of the charging cable. It should be noted here that the first side 31 of the adapter is equipped with a seven-pin socket identical or similar to that found on vehicles, which is the male-female counterpart of the first plug 11. The first side 31 of the adapter only has the 3 wires L1 N and PE, which are to be put into electrical connection with the corresponding conductors of the charging cable when coupling the adapter 3 to the first plug 11.

[0065] The second side 32 of the adapter 3 comprises a conventional 2P+T male plug, it can be connected to a 2P+T domestic socket (6) or to a Wallbox socket.

[0066] A storage space may be provided to allow a user to store the adapter 3 in the vehicle so that it can be used if necessary. Alternatively, the adapter 3 may be attached by a flexible tie to the first end E1 of the cable. recharging.

[0067] In [Fig. 3], an electric vehicle 9 is shown in a charging situation at a public charging station 5. Note that for this configuration the adapter 3 is not used.

[0068] The charging cable 1 connects the vehicle to the charging station. The charging cable 1 has a first plug 11 allowing electrical coupling with an electrical charging source arranged in the charging station itself, and a first end 12 connected to the on-board control box 2.

[0069] The charging cable 1 is shown here in the deployed configuration. The distance LC which separates the vehicle from the terminal is highly variable depending on the configurations that arise. In some cases, LC is less than 2 meters, in other cases the distance LC can be between 2 meters and 5 meters. Configurations where the distance LC is greater than 5 meters also exist.

[0070] The first plug 11 is of type 2 with seven sockets. Type 2 is defined in relation to the standard IEC62196.3 which defines the seven standard electrical channels and their respective positions, they are shown in [Fig.5].

[0071] It should be noted that in the application presented here the proximity pilot (PP) is not used, there is no wire / conductor in front of the corresponding pin.

[0072] As shown in [Fig.7], for single-phase charging, it is the neutral N and the first phase (wire L1) which are used, the other phases L2 and L3 are not used. A first-section conductor SI supports a permanent current (its amperage rating) up to the value Sl-Imax (left-hand ordinate graduated in Amperes). A second-section conductor S2 supports a permanent current up to the value S2-Imax. The charging power is noted PR (right-hand ordinate graduated in kilowatt kW). The maximum power parameter allowed by the battery recharge is noted PR-max.

[0073] For three-phase charging, the three phases L1, L2 and L3 are used in a balanced manner.

[0074] Preferably in three-phase, the conductors of the second phase L2 and third phase L3 are used at their maximum rating. This condition makes it possible to size the second cross-section S2 within the meaning of the present invention for a maximum target charging power.

[0075] The on-board control box 2 transforms the incident electrical energy, whether single-phase or three-phase, into a positive and negative two-conductor output to recharge the battery.

[0076] In the control box 2, it may be provided to detect the presence of phase on the conductors L2 and / or L3 to determine whether the cable is connected to a source three-phase or to a single-phase source. Depending on this, and the available power information provided by the charging station, the control box 2 sets the charging current to the maximum possible with regard to the power admissible by the battery and the characteristics of the charging cable.

[0077] In the variant illustrated in [Fig.6], the adapter 3 comprises a recharge control device 30.

[0078] Depending on the functional content of the on-board control box 2, it may be necessary to have the charging control device 30 on the adapter itself in addition.

[0079] In this document, by convention, the phase dedicated to single-phase has been considered as the first (L1), but of course it could instead be the second phase or the third phase.

Claims

Claims

1. Charging cable (1) for charging an electric vehicle, the charging cable comprising at least five electrical conductors including three phase conductors (L1, L2, L3) and a neutral conductor (N), the cable extending between a first end (El) and a second end (E2), characterized in that the phase conductors have at least two different cross-sections (S1, S2), including a first cross-section (SI) and a second cross-section (S2) smaller than the first cross-section, and in that the first phase conductor (L1) has as its cross-section the first cross-section (SI) and the second phase (L2) and third phase (L3) conductors have as its cross-section the second cross-section (S2), and the neutral conductor (N) has as its cross-section the first cross-section (SI).

2. Charging cable according to claim 1, characterized in that it further comprises a protective conductor (PE) which has as its cross-section the first cross-section (SI).

3. Charging cable according to any one of claims 1 to 2, characterized in that the first cross-section (SI) is at least twice as large as the second cross-section (S2).

4. Charging cable according to any one of claims 1 to 3, characterized in that it further comprises a control conductor (CP) which has as a section a third cross-section (S3), smaller than the second cross-section (S2).

5. Charging cable according to any one of claims 1 to 4, characterized in that it comprises six conductors.

6. Charging cable according to any one of claims 1 to 5, characterized in that it comprises at its first end (El) a first plug (11) of type 2 with 7 cells within the meaning of standard IEC62196.

3.

7. Charging cable according to any one of claims 1 to 6, characterized in that a main portion of the cable between the first end and the second end has a helical shape, the charging cable thus being extensible.

8. Charging cable according to claim 7, characterized in that it has in a deployed configuration a length (LC) at least equal to 5 meters.

9. An assembly comprising a charging cable according to any one of the claims 1 to 8, and an adapter (3) comprising a first connector (31) forming a counterpart of a first plug (11) of the charging cable and a second connector (32) configured to be plugged into a charging base of the domestic socket type (6).

10. Motor vehicle comprising a charging cable according to any one of claims 1 to 8, the second end (E2) being connected to a control box (2) configured to control charging modes of the vehicle in order to benefit from the greatest available power depending on the charging source.

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