FAST CHARGING DEVICE FOR AN ELECTRIC OR HYBRID VEHICLE

Description

GENERAL TECHNICAL FIELD

[0001] The invention relates to the field of electric or hybrid vehicles. And it relates more specifically to the fast charging of such vehicles. STATE OF THE ART

[0002] The advent of electric vehicles has necessitated the development of battery charging solutions for these vehicles. Documents WO 2019 / 062972 A2 and US 2016 / 082943 A1 describe charging devices for electric vehicles.

[0003] As illustrated on the figure 1 ,To recharge an electric vehicle 1, the vehicle's battery 10 is connected to the electrical network 2 by a charging unit comprising two cables 31, 32, 31', 32' on either side of a connector 50. The connector 50 allows the charging unit to be connected or disconnected from the vehicle. The vehicle is charged using either alternating current or direct current, as the vehicles are equipped to be charged using either type of current.

[0004] In the context of a direct current charge, inside the vehicle, two cables 31, 32 are connected on one side to the terminals of the vehicle's battery 10 (a cable 31 for the positive terminal of the battery and a cable 32 for the negative terminal of the battery) and on the other side to the connector 50. The part between the connector 50 and the battery is therefore located inside the vehicle 1.

[0005] Outside the vehicle, two cables 31', 32' are connected on one side to connector 50 and on the other side to electrical network 2. The part between connector 50 and electrical network 2 is therefore outside the vehicle 1.

[0006] For the outside part, the two cables 31', 32' are preferably arranged within the same sheath to form a power cable 40.

[0007] As illustrated on the figures 2 And 3 , For the inner part, the cables 31, 32 are insulated separately and protected together with one or more braids 30, of textile or metallic nature. In particular, each load cable 31, 32 comprises an electrical conductor 8 surrounded by an insulating layer 9.

[0008] The outer part and the inner part constitute a load unit, the inner part constitutes an internal load device.

[0009] To date, the charging systems developed allow for charging times of several hours (8 hours, for example). These durations are considered too long for convenient use of these vehicles.

[0010] Therefore, there is a need to reduce these durations with the objective of reaching durations of 15 minutes, or even 5 minutes, for a complete battery recharge.

[0011] As is known, to decrease charging time, the electric current must be increased.

[0012] However, such an increase in electric current is not without problems since excessive heating of the system is observed by joule effect (W=RI 2< ).

[0013] Specifically, the connector is designed for long-duration charging, but it is intended for short-duration use. However, with an undersized conductive cross-section, this results in a significant temperature increase on the connector during fast charging.

[0014] One solution to mitigate this excessive heating is to increase the cross-sectional area of ​​electrical conductors in cables and connectors.

[0015] However, for standardization reasons, modifying the connector is not feasible. Furthermore, increasing the cross-sectional area inevitably leads to an increase in the cost and weight of the charging device, which is undesirable. PRESENTATION OF THE INVENTION

[0016] The invention proposes to overcome the aforementioned drawback.

[0017] To this end, the invention proposes, according to a first aspect, a charging device for hybrid or electric vehicles intended to be connected to an electricity distribution network, on the one hand, and to the terminals of a battery of a hybrid or electric vehicle, on the other hand, said device comprising two charging cables, each intended to be connected to a terminal of the battery, each charging cable comprising an electrical conductor and at least one insulating layer surrounding the electrical conductor, each charging cable further comprising a protection device consisting of at least one sheath arranged around the insulating layer, conforming to the assembly formed by the electrical conductor and the insulating layer.

[0018] The invention is advantageously complemented by the following features, taken alone or in any technically possible combination thereof: said at least one sheath is arranged by an extrusion or co-extrusion process so as to be in intimate non-adherent contact with the layer on which the sheath is arranged; said at least one sheath is a heat-shrinkable sheath so as to be in intimate non-adherent contact with the layer on which the sheath is arranged; the protective device comprises a first sheath in contact with the insulating layer; the protective device further comprises a second sheath in contact with the first sheath; the first sheath and the second sheath have identical or different radial thicknesses; the first sheath and the second sheath are made of identical or different materials; the first sheath and the second sheath, where applicable, are made of a material selected from: thermoplastic polymers, for example polyvinyl chloride, polyethylene, etc.The charging device includes a connector comprising an input intended to be connected to a power cable which is itself connected to an electrical network, and an output from which the charging cables extend.

[0019] The invention relates, according to a second aspect, to a charging assembly for a hybrid or electric vehicle comprising a charging device according to the first aspect of the invention and a power cable intended to be connected to an electricity distribution network.

[0020] Using one or more sheaths that perfectly fit the assembly formed by the conductor and the insulating layer, instead of a classic braid used to surround the cables, helps to promote heat dissipation.

[0021] By using charging cables with at least one sheath that conforms to the assembly formed by the conductor and the insulating layer, air gaps are eliminated and heat dissipation from the charging device inside the vehicle and at the connector is improved. Fast charging is therefore now possible.

[0022] The conventional use of one or more braids, which provide electrical and / or mechanical protection for the charging cable, creates air gaps between the charging cables and also between the braids themselves. These air gaps hinder heat dissipation.

[0023] Indeed, the charging device, particularly when connected to the connector, allows for the dissipation of heat: by thermal conduction from the connector to the electrical conductor of the charging cable; by thermal conduction through the insulation of the charging cable; by thermal conduction through the charging cable's braid (providing mechanical and electrical protection) and the air gap created by this braid; and by natural convection and radiation towards the surrounding environment. Furthermore, the heat dissipation of the power generated by Joule heating in the electrical conductors depends on the conductivity of the conductor, the nature of the insulation layer, the type of braid, and, of course, the presence of an air gap.

[0024] Consequently, the advantages of the invention are as follows: promotes heat exchange between cable and environment; allows for faster dissipation of heat brought to the connector; allows for time savings in the implementation of the charging cable system; allows for time savings in the manufacturing of the electrical harness entering the charging device; allows for a reduction in charging time (increasing the charging current). PRESENTATION OF FIGURES

[0025] [ Fig. 1 ] [ Fig. 2 ] [ Fig. 3 ] [ Fig. 4 ] [ Fig. 5 ]

[0026] Other features, purposes, and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings, in which, in addition to the figures 1 to 3 already discussed: there figure 4 illustrates an overview of an electric vehicle charging device according to the invention; the figure 5illustrates a detailed view of a charging cable of a charging device according to the invention.

[0027] Across all figures, similar elements bear identical references. DETAILED DESCRIPTION

[0028] We illustrated on the Figures 4 and 5 A charging device for an electric or hybrid vehicle intended to be installed in the interior of the electric or hybrid vehicle. Such a device includes a connector 50 from which two charging cables 61, 62 extend to the battery (not shown). In particular, the charging cables 61, 62 exit the terminals of connector 50 independently of each other. They are not enclosed in any sheath or tube as is the case in the prior art (see figure 2In this way, the charging cables 61 and 62 can run independently of each other inside the vehicle to reach the battery and thus pass through separate spaces. This facilitates the installation of the charging device.

[0029] Each charging cable 61, 62 must support a reference current that depends on the charging time required for the battery. For example, charging a 36kW battery with AC requires 10 hours to fully recharge it (230Vac x 16Ah = 3.6kWh).

[0030] Each charging cable includes, as discussed above, an electrical conductor 8 surrounded by an insulating layer 9.

[0031] The electrical conductor 8 is, for example, made of copper, a copper alloy, aluminum or an aluminum alloy, etc.

[0032] The insulating layer 9 is for example made of thermoplastic material, PVC (lead-free polyvinyl chloride), XLPE (cross-linked polyethylene), etc.

[0033] Advantageously, each charging cable is identical in order to have a homogeneous distribution of the current.

[0034] Unlike the configuration presented in the introduction, the load cables are not surrounded together by one or more braids but are individually surrounded by a protective device G comprising one or two sheaths G1, G2. Thus, for each load cable, the assembly formed by the electrical conductor and the insulating layer is surrounded by the protective device G.

[0035] It can be anticipated that the protection device G will comprise a first sheath G1 and possibly a second sheath G2. It should be understood that the term "sheath" used here is in no way comparable to any kind of braid.

[0036] In addition, one charging cable may be surrounded by two sheaths while the other is surrounded by only one sheath.

[0037] Each sheath is advantageously arranged using an extrusion or co-extrusion process to ensure non-adherent contact with the layer on which it is placed. This non-adherent contact facilitates the installation of the charging device, particularly when stripping the charging cable for connection to the battery.

[0038] The sheath can be heat-shrinkable.

[0039] More precisely, in the case of a single-sheath protective device, the sheath is in non-adherent contact with the insulating layer 9 of the load cable, whereas in the case of a two-sheath protective device (G1, G2), the second sheath is in non-adherent contact with the first sheath (G1). As can be understood, the sheath is in close contact with the layer on which it is deposited, thus preventing air gaps. Indeed, returning to the figure 3 which shows two cables grouped in two braids 30, air gaps 70 are present between the cables but also between the braids.

[0040] Each G1, G2 sheath is made of homogeneous polymeric material and is for example made of: PVC (lead-free polyvinyl chloride), XLPE (cross-linked polyethylene), etc.

[0041] In the case of two sheaths, it can be assumed that each sheath is made of a different material. Each type of sheath independently meets the stresses (electrical, mechanical, thermal) that are difficult to verify with a single type of material.

[0042] Each sheath can have a radial thickness between 0.5 mm and 1.5 mm, preferably 0.7 mm or even 1 mm. Furthermore, it can be anticipated that in the case of a protective device comprising two sheaths, G1 and G2, will not have the same radial thickness. Of course, the thickness of both sheaths can be identical. The greater the thickness of at least one sheath, the larger the cable cross-section, thus promoting heat dissipation.

[0043] The first sheath G1 may have a radial thickness greater or less than the thickness of the second sheath G2.

[0044] According to a preferred embodiment, each charging cable is surrounded by two sheaths and has the following characteristics: Radial thickness of sheath G1: 1 mm Radial thickness of sheath G2: 0.70 mm Radial thickness of insulating layer: 2 mm Diameter of conductor element: 12.6 mm.

[0045] A configuration with two charging cables with the above characteristics was tested by passing a current of 350 A through each charging cable and compared to a configuration as presented in the introduction with two braids (see the figure 3 ). - Thickness of braid 1: 1 mm - Thickness of braid 2: 0.70 mm - Average equivalent thickness of air gap: 5 mm - Radial thickness of insulating layer: 2 mm - Diameter of conductive element: 12.6 mm. [Table 1] Configuration figure 3 with two braids Configuration with two ducts Internal conductor temperature rise 57,2°C 33,2°C Temperature rise in the insulating layer 54,5 °C 28,3°C Temperature rise at the connector 60,4°C 46,2°C

[0046] We can clearly see a significant decrease in the temperature rise at several points in the charging device.

Claims

1. A fast charging device for a hybrid or electric vehicle intended to be connected to an electricity distribution network (2), on the one hand, and to the terminals of a battery (10) of a hybrid or electric vehicle, on the other hand, said device comprising: - two charging cables (61, 62) adapted to run independently of each other inside a vehicle, the two cables not being surrounded by any sheath or tube common to the two cables; - a connector (50) comprising an input for connection to a power cable to be connected to an electricity distribution network, and an outlet from which the load cables extend; each of the two cables being intended to be connected to a battery terminal at one end of the cable, and at the other end to a respective terminal of the connector output (50), each charging cable (61, 62) comprising an electrical conductor (8) and at least one insulating layer (9) surrounding the electrical conductor (8), the insulating layer (9) being in direct contact with the electrical conductor (8); each charging cable further comprising a protective device (G) consisting of at least one sheath (G1, G2) arranged around the insulating layer and conforming to the assembly formed by the electrical conductor (8) and the insulating layer (9), a sheath of the at least one sheath of the protective device (G) being in direct contact with the insulating layer so as to promote heat dissipation from the charging device inside the vehicle and at the connector.

2. The charging device according to claim 1, wherein said at least one sheath is arranged by an extrusion, or co-extrusion process so as to be in intimate non-adherent contact with the layer on which the sheath is arranged.

3. The charging device according to claim 1, wherein said at least one sheath is a heat-shrinkable sheath so as to be in intimate non-adherent contact with the layer on which the sheath is arranged.

4. The charging device according to any one of claims 1 to 3, wherein the protective device (G) further comprises a second sheath (G2) in contact with the first sheath (G1).

5. The charging device according to claim 4, wherein the first sheath (G1) and the second sheath (G2) have identical or different radial thicknesses.

6. The charging device according to any of claims 4 to 5, wherein the first sheath (G1) and the second sheath (G2) are made of the same or different materials.

7. The charging device according to one of claims 4 to 5, wherein the first sheath (G1) and the second sheath (G2), if any, is made of a material selected from: thermoplastic polymers e.g. polyvinyl chloride, polyethylene.

8. Charging assembly for a hybrid or electric vehicle comprising a charging device according to one of the preceding claims and a supply cable intended to be connected to an electricity distribution network.