Power line assembly and motor vehicle

Abstract

The invention relates to a power line assembly (10) for conducting electric power from a charging socket (160) of a motor vehicle (100) to an energy storage device (150) of the motor vehicle (100), comprising a direct-current line (20) with two individual direct-current lines (21, 22) for conducting a direct current (DC) from a direct-current interface (120) of the charging socket (160) to the energy storage device (150) and comprising an alternating-current line (30) with a plurality of individual alternating-current lines (31) for conducting an alternating current (AC) from an alternating-current interface (130) of the charging socket (160) to the energy storage device (150), wherein each of the individual direct-current lines (21, 22) has a profiled aluminum section (25) as an electric conductor for conducting the direct current (DC).

Description

[0001] Power line arrangement and motor vehicle

[0002] The present disclosure relates to a power line arrangement for conducting electrical current from a charging socket of a motor vehicle to an energy storage device of the motor vehicle. The disclosure also relates to a motor vehicle.

[0003] The ongoing mobility transition is a critical aspect in the context of the increasing need for environmental sustainability. For this and other reasons, the production and use of electric vehicles are a key component in achieving more sustainable mobility. A central component of an electric vehicle is the charging chain or charging unit, which runs from an energy storage device via a power line arrangement to a charging socket. An external charging station can be connected to the charging socket to charge the energy storage device.

[0004] The charging unit comprises the power line assembly and a charging port or interface for connecting the power line assembly to the charging socket, as well as an interface to the energy storage device. The power line assembly or cable runs between the energy storage device and the charging socket. This charging unit is typically a single, integrated component.

[0005] The motor vehicle can typically be charged with either an alternating current (AC) or a direct current (DC) via an alternating current (AC) and a direct current (DC) cable harness.

[0006] According to the state of the art, the DC cable harness typically consists of two round copper conductors. One of the round conductors is positively charged and the other negatively charged when transporting current. Copper is suitable for round conductors because, in addition to the basic requirement of current-carrying capacity, it is mechanically flexible and can therefore compensate for tolerances in the arrangement of the charging unit or charging socket and the energy storage device. However, copper exhibits a comparatively high heat input when carrying direct currents. Copper is comparatively expensive and has a comparatively high mass.

[0007] WO 2016 / 020512 A1 discloses a vehicle with a storage device for electrical energy that can be recharged by means of a charging cable and an external power supply, and with a body that has at least one body opening that can be closed by a body flap, wherein a charging cable is provided that is or can be connected in an electrically conductive manner to the storage device and that runs at least partially inside the body, is characterized in that the body opening is a luggage compartment opening or a door opening and the body flap is a luggage compartment flap or a door of the vehicle; that the charging cable is designed as a flexible ribbon cable or has at least one flexible ribbon cable section;that the flexible ribbon cable or the at least one flexible ribbon cable section can be passed through a body gap present between an edge of the body opening and the body flap and that the ribbon cable or the at least one flexible ribbon cable section has current-carrying conductors arranged next to one another, which are designed as flat, ribbon-shaped conductors and which are surrounded by a common, electrically insulating sheath;

[0008] Against the background of this prior art, the object of the present disclosure is to provide an improved power line arrangement that is suitable for enriching the prior art. A specific embodiment of the disclosure can achieve the object of providing a cost-effective, lightweight, and easy-to-maintain power line arrangement that comparatively effectively avoids heat-related problems.

[0009] The problem is solved by the features of the independent claim. The subclaims contain preferred developments of the disclosure.

[0010] According to this invention, the problem is solved by a power line arrangement for conducting electrical current from a charging socket of a motor vehicle to an energy storage device of the motor vehicle. The power line arrangement comprises a direct current line with two individual direct current lines for conducting a direct current from a direct current interface of the charging socket to the energy storage device, and an alternating current line with several individual alternating current lines for conducting an alternating current from the alternating current interface of the charging socket to the energy storage device. Each of the individual direct current lines has an aluminum profile as an electrical conductor for conducting the direct current.

[0011] The power line arrangement is thus arranged between the charging socket and the energy storage device within the motor vehicle. The power line arrangement comprises the direct current line and the alternating current line to enable combined charging. This allows both a direct current and an alternating current charging method for charging the energy storage device.

[0012] The DC line has two individual DC lines, one of which corresponds to a positive pole and the other of which corresponds to a negative pole.

[0013] The AC line comprises a plurality of individual AC lines. This allows charging with multi-phase AC and / or three-phase AC.

[0014] The direct current line and the alternating current line are each configured to be connected to the energy storage device via a corresponding interface. To charge battery cells of the energy storage device, the energy storage device may include power electronics for converting the direct current and / or the alternating current.

[0015] Each of the individual DC lines has an aluminum profile as an electrical conductor for conducting the direct current. This provides an aluminum profile for conducting the direct current. Aluminum is lighter than copper and, thanks to its effective recycling, is cost-effective. Furthermore, aluminum has a comparatively high thermal conductivity. The profiled shape of the individual DC lines can improve the thermal radiation and / or thermal conduction of a heated DC line, thus effectively cooling the DC line. This can reduce the charging time for the energy storage device. A profile is a part formed, for example, from a flat piece.

[0016] The aluminum profiles of the individual DC lines can be arranged parallel to each other. This allows the magnetic fields of the two individual DC lines to partially cancel each other out. When current flows through a conductor, an electromagnetic field is created. Because the two aluminum profiles are oppositely charged, the two generated electromagnetic fields partially cancel each other out, requiring fewer or no additional measures to neutralize the electromagnetic fields. The proposed positioning of the aluminum profiles facilitates the achievement of electromagnetic compatibility limits. Electromagnetic compatibility (EMC) refers to the ability of a technical device not to interfere with other devices through unwanted electrical and / or electromagnetic effects, nor to be interfered with by other devices.

[0017] The aluminum profiles can be flat profiles. This means that the aluminum profiles have two main expansion directions, in which the aluminum profiles exhibit a greater expansion than in a further expansion direction. It was recognized that, for example, round aluminum profiles are comparatively rigid and cannot compensate for possible tolerances in the arrangement of the charging unit and the energy storage device. The flat profile shape creates the necessary flexibility of the aluminum profiles. Flat profiles are comparatively flexible and can suitably compensate for such tolerances in motor vehicles.

[0018] A heat storage paste can be placed between the individual DC lines. A thermal paste made of, for example, LH2C is inserted between the two aluminum profiles. This paste has a high thermal capacity and can absorb the heat from the lines. This results in increased current carrying capacity, shorter charging times, and the heat absorption via the heat storage paste applied between the aluminum profiles is more cost-effective than active cooling.

[0019] In other words, the above description can be summarized as follows, referring to a specific embodiment that is described as non-limiting to the present disclosure: It is proposed to replace the two round-profile copper cables of the DC charging line with two flat-profile aluminum cables. The flat profiles are placed one above the other so that the magnetic fields of the two flat-profile cables partially cancel each other out. When current flows through a conductor, an electromagnetic field is created. Since the two flat profiles are oppositely charged, the two generated electromagnetic fields partially cancel each other out, and no additional measure is required to neutralize the electromagnetic fields.Electromagnetic compatibility (EMC) refers to the ability of a technical device not to interfere with other devices through unwanted electrical or electromagnetic effects, or to be interfered with by other devices. The proposed positioning of the flat profiles makes it easier to achieve EMC limits. Using aluminum instead of copper allows for lower costs, better heat dissipation, and the resulting shorter charging time. However, round aluminum profiles are very rigid and cannot compensate for possible tolerances in the charging unit and the high-voltage battery. In addition, the charging unit consists of several components, so tolerances between the individual components of the charging unit are necessary. Modifying the shape creates the necessary flexibility of the aluminum profiles. Flat profiles are more flexible and can better compensate for tolerances.In order to achieve a short charging time and high charging efficiency, it is important to keep the temperature in the charging path low. Due to the resistance in the cables, heat is released, which can affect the environment (e.g. the sheath) and, above a certain temperature, reduce the charging performance. Air and water cooling are not suitable because they have disadvantages in the following areas: complexity, cost, packaging (installation space), and weight. Therefore, it is proposed to place thermal cooling via a thermal mass (LH2C) between the two flat aluminum profiles. A thermal paste made of LH2C is inserted between the two aluminum profiles. This paste has a high heat capacity and can absorb the heat from the cables.

[0020] Furthermore, a motor vehicle is provided. The motor vehicle comprises a charging socket, an energy storage device, and the power line arrangement described above.

[0021] The motor vehicle can be a passenger car, in particular an automobile. The motor vehicle can be an electrically driven motor vehicle. For this purpose, the motor vehicle can have an electric drive that can be supplied with electrical energy from the energy storage device in order to convert electrical energy into kinetic energy. The optionally automated motor vehicle can be designed to at least partially and / or at least temporarily assume longitudinal guidance and / or lateral guidance during automated driving of the motor vehicle. Automated driving can occur such that the movement of the motor vehicle is (largely) autonomous. Automated driving can be at least partially and / or temporarily controlled by the data processing device. The motor vehicle can be a motor vehicle of autonomy levels 0 to 5.

[0022] What has been described above with reference to the power line arrangement also applies analogously to the motor vehicle and vice versa.

[0023] An embodiment is described below with reference to Figures 1 to 4.

[0024] Fig. 1 schematically shows a motor vehicle according to an embodiment of the disclosure;

[0025] Fig. 2 shows a perspective view of a power line assembly according to one aspect of the disclosure;

[0026] Fig. 3 schematically shows cross sections of a DC line of a current conductor arrangement according to one aspect of the disclosure; and Fig. 4 schematically shows a screw connection of a current conductor arrangement according to one aspect of the disclosure.

[0027] Figure 1 schematically shows a motor vehicle 100 according to an embodiment of the disclosure.

[0028] The motor vehicle 100 comprises a charging socket 160, an energy storage device 150, and a power line arrangement 10. The charging socket 160 is configured to establish an electrical connection between the motor vehicle 100 and an external charging station 200. Via this connection, the motor vehicle 100 or its energy storage device 150 can be supplied with an electrical current and charged.

[0029] For this purpose, the charging socket 160 is connected to the energy storage device 150 for conducting electrical current via the power line arrangement 10. The power line arrangement 10 is configured to conduct electrical current from the charging socket 160 to the energy storage device 150.

[0030] The power line arrangement 10 comprises a direct current line 20 and an alternating current line 30.

[0031] The direct current line 20 is configured to conduct a direct current DC from a direct current interface 120 of the charging socket 160 to the energy storage device 150. The alternating current line 30 is configured to conduct an alternating current AC from the alternating current interface 130 of the charging socket 160 to the energy storage device 150.

[0032] The AC line 30 has several individual AC lines 31 (only one individual AC line 31 is illustrated for the sake of clarity).

[0033] The power line arrangement 10 is also described with reference to Figures 2 to 4.

[0034] Figure 2 shows a perspective view of a power line assembly 10 according to one aspect of the disclosure. The power line assembly 10 is a power line assembly 10 for a motor vehicle 10. Such a motor vehicle 10 is described with reference to Figure 1. Figure 2 is described with reference to Figure 1 and its description.

[0035] The AC line 30 according to Figure 2 comprises a plurality of individual AC lines 31 arranged in a sheath 38 and electrically insulated from one another. The individual AC lines 31 are made of copper, for example, and each have a round cross-section. The sheath 38 is electrically insulating and made of a plastic, for example.

[0036] The power line arrangement 10 has an AC plug connection 33 connectable to the AC line 30. The AC plug connection 33 is configured to connect the power line arrangement 10 to the AC interface 160. The AC plug connection 33 has a plug and an associated socket (not shown). At a not-shown end of the AC line 30, the power line arrangement 10 has a further AC plug connection 33 configured to connect the power line arrangement 10 to the energy storage device 150. Thus, the energy storage device 150 can be electrically connected to the charging socket 160 for transmitting an alternating current AC via the AC plug connection 33 and the AC line 30.

[0037] As shown in Figure 2, the direct current line 20 is configured to be electrically conductively fastened to the direct current interface 120 by a screw connection 24 having a plurality of screws 23. Such a screw connection 24 is described in detail with reference to Figure 4. At an end of the direct current line 20 not shown in Figure 2, the direct current line 20 is configured to be electrically conductively fastened to the energy storage device 150 by a further screw connection 24 having a plurality of screws 23. The energy storage device 150 can thus be electrically connected to the charging socket 160 for transmitting a direct current DC via the screw connections 24 and the direct current line 20. The direct current line 20 is described in more detail with reference to Figure 3.

[0038] As shown in Figure 2, the power line arrangement 10 has a ground 40 for connection to the motor vehicle 100.

[0039] Figure 3 schematically shows cross-sections of a DC line 20 of a current conductor arrangement 10 according to one aspect of the disclosure. Figure 3 shows the current conductor arrangement 10 described with reference to Figures 1 and 2. Figure 3 is described with reference to Figures 1 and 2 and their descriptions.

[0040] Figure 3 shows four different embodiments of the DC line 20 (Figures 3 (A), 3 (B), 3 (C) and 3 (D)).

[0041] According to Figure 3, the direct current line 20 has two individual direct current lines 21, 22 for conducting a direct current DC. Each of the individual direct current lines 21, 22 has an aluminum profile 25 as an electrical conductor for conducting the direct current DC. The aluminum profiles 25 are flat profiles 26. This means that each of the aluminum profiles 25 has two main directions of extension, here horizontal and into the plane of the drawing, and a further direction of extension, here vertical. The extension of the aluminum profiles 25 is greater in the main directions of extension than in the further direction of extension. The aluminum profiles 25 can be produced, for example, by rolling and forming.

[0042] The aluminum profiles 25 of the individual DC lines 21, 22 are arranged parallel to one another. The respective main directions of extension of the aluminum profiles 25 define a plane in which the aluminum profiles 25 each have a largest area. The aluminum profiles 25 of the individual DC lines 21, 22 are arranged such that their largest areas are parallel to one another.

[0043] The DC line 20 has insulation 28. The insulation 28 is arranged around the individual DC lines 21, 22 and between the individual DC lines 21, 22. The insulation 28 is electrically insulating and made of a plastic, for example.

[0044] Figure 3 (B) is described with regard to the differences from Figure 3 (A). According to Figure 3 (B), the DC line 20 has insulation 28. The insulation 28 is arranged around each of the individual DC lines 21, 22. An air gap is arranged between the insulation 28 of the individual DC lines 21, 22. The air gap can achieve improved heat dissipation from the individual DC lines 21, 22 to the surroundings.

[0045] Figure 3 (C) is described with regard to the differences from Figure 3 (A). According to Figure 3 (C), the direct current line 20 has a heat storage paste 27 arranged between the individual direct current lines 21, 22.

[0046] The heat storage paste 27 has a high heat capacity compared to aluminum and is designed to absorb heat generated in the DC line 20 during a charging process. This reduces the temperature of the DC line 20, which can be beneficial for charging.

[0047] The heat storage paste 27 has a pasty consistency. This allows the heat storage paste 27 to be effectively arranged according to the possibly curved contour (see Figure 2) of the DC line 20.

[0048] The heat storage paste 27 contacts the individual DC lines 21, 22 at one of their largest surfaces to enable effective heat transfer from the respective individual DC lines 21, 22 to the heat storage paste 27. The heat storage paste 27 is electrically insulating and thus forms electrical insulation between the individual DC lines 21, 22.

[0049] Figure 3 (D) is described with regard to the differences from Figure 3 (C). According to Figure 3 (D), the sheath 28 is arranged to enclose the heat storage paste 27. The heat storage paste 27 has no direct electrical contact with the individual DC lines 21, 22. Thus, an electrically conductive heat storage paste 27 can also be used.

[0050] Figure 4 schematically shows a screw connection 24 of a conductor assembly 10 according to one aspect of the disclosure. Figure 4 shows the conductor assembly 10 described with reference to Figures 1 to 3. Figure 4 is described with reference to Figures 1 to 3 and their descriptions.

[0051] The DC line 20 is electrically secured to the DC interface 120 by a screw connection 24 comprising two screws 23. Each of the screws 24 is arranged perpendicular to one of the aluminum profiles 25 when mounted. Each of the screws 24 makes electrical contact with exactly one of the aluminum profiles 25.

[0052] Each of the aluminum profiles 25 has a first through-opening 29a and a second through-opening 29b, each for passing through one of the screws 24. The through-openings 29a, 29b of each of the aluminum profiles 25 have different diameters D. In other words, each of the aluminum profiles 25 has a through-opening 29a with a diameter D that is larger than a diameter D of the other through-opening 29b. For the through-openings 29b with the smaller diameter D, a tolerance range is provided, i.e., the diameter D of the smaller through-opening 29b is slightly larger than the diameter of the screws 24. The diameter D of the smaller through-opening 29b is selected such that a reliable mechanical and electrical connection is achieved between the individual DC lines 21, 22 and the charging socket 160.The diameter D of the larger through-hole 29a is selected such that contact of the screw 24 with the respective individual DC lines 21, 22 at the larger through-hole 29a is excluded. For example, the larger through-hole 29a has a diameter D that is equal to a multiple of the diameter of the screws 24.

[0053] The screws 24 are guided vertically through the individual DC lines 21, 22, such that each screw 24 is only connected to one individual DC line 21, 22. The two screws 24 are in contact with the different individual DC lines 21, 22. Both screws 24 are guided through both individual DC lines 21, 22, but only come into contact with one of the individual DC lines 21, 22. The connection between screw 24 and individual DC lines 21, 22 for an electrical connection or separation is created by a small or large distance between screw 24 and individual DC lines 21, 22, i.e. by the different diameters D of the through-openings 29a, 29b. The power line arrangement 10 has a cover cap 41 or a contact cap. The cover cap 41 is electrically insulating.The cover cap 41 can protect the screw connection 24 from mechanical influences.

[0054] List of reference symbols

[0055] 10 Power line arrangement

[0056] 20 DC line

[0057] 21 DC single line

[0058] 22 DC single line

[0059] 23 Screw connection

[0060] 24 screw

[0061] 25 aluminum profile

[0062] 26 flat profile

[0063] 27 Heat storage paste

[0064] 28 Insulation

[0065] 29a first passage opening

[0066] 29b second passage opening

[0067] 30 AC line

[0068] 31 single AC lines

[0069] 33 AC plug connection

[0070] 38 Wrapping

[0071] 40 mass

[0072] 41 Cover cap

[0073] 100 motor vehicles

[0074] 120 DC interface

[0075] 130 AC interface

[0076] 150 energy storage device

[0077] 160 charging socket

[0078] 200 charging stations

[0079] AC alternating current

[0080] DC direct current

[0081] D Diameter

Claims

Patent claims Power line arrangement (10) for conducting electrical current from a charging socket (160) of a motor vehicle (100) to an energy storage device (150) of the motor vehicle (100), comprising - a direct current line (20) with two individual direct current lines (21, 22) for conducting a direct current (DC) from a direct current interface (120) of the charging socket (160) to the energy storage device (150), and an alternating current line (30) with several individual alternating current lines (31) for conducting an alternating current (AC) from an alternating current interface (130) of the charging socket (160) to the energy storage device (150), characterized in that - each of the individual direct current lines (21, 22) has an aluminum profile (25) as an electrical conductor for conducting the direct current (DC). Power line arrangement (10) according to claim 1, wherein the aluminum profiles (25) of the individual direct current lines (21, 22) are arranged parallel to one another. Power line arrangement (10) according to claim 1 or 2, wherein the aluminum profiles (25) are flat profiles (26). Power line arrangement (10) according to one of the preceding claims, wherein a heat storage paste (27) is arranged between the individual direct current lines (21, 22). Motor vehicle (100), comprising a charging socket (160), an energy storage device (150), and a power line arrangement (10) according to one of the preceding claims.

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