Charging device for connecting an electrical energy storage device of a motor vehicle to a charging station

Abstract

The invention relates to a charging device (10) for connecting an electrical energy storage device (14) of a motor vehicle (16) to a charging station (24) for electrical energy, the charging device comprising a charging cable (12) having at least one conductor (18) for conducting a charging current, via which the charging cable (12) can be connected to a corresponding connecting element (22) between the energy storage device (14) and the charging station (24), at least one latent heat accumulator (26) being arranged on the charging cable (12) and / or on the at least one connecting element (20), by means of which heat generated during the charging process can be absorbed.

Description

Technical Field

[0001] The invention relates to a charging device for connecting an electrical energy storage device of a motor vehicle to a charging station for electrical energy. Background Art

[0002] Electrically driven motor vehicles, in particular in the form of passenger cars, usually have an energy storage device for storing electrical energy, in particular in the form of a traction battery. The size of the energy storage device or battery determines the driving range of the motor vehicle. In addition to the charging time required to fill the energy storage device with electrical energy, the driving range is also an important factor in the acceptance of electric vehicles or the conversion to electric vehicles.

[0003] There are various ways to improve the low driving range compared to a motor vehicle driven by an internal combustion engine or to make the long charging time particularly short. The charging time is dependent on the charging speed. If, for example, the electrical energy is provided by a charging station with particularly high power, the charging speed of the motor vehicle can depend on the maximum electrical energy intake of the motor vehicle. The main limiting factor is the heat generated by the flow of current, which can be generated in particular by power losses, for example in contact resistances. If the generated heat heats up, for example, several components of a component involved in the charging process, this can lead to overheating, which necessarily reduces the charging speed.

[0004] For example, DE 10 2017 010 038 A1 describes a charging device for inductively charging an energy storage device of a motor vehicle, which has at least one charging coil for inductively transmitting electrical energy for charging the energy storage device, the charging coil being at least partially embedded in a material by means of which heat can be absorbed from the charging coil for passive cooling thereof. Summary of the invention

[0005] It is therefore an object of the present invention to provide a charging device with which an electrical energy storage device of a motor vehicle can be charged at a particularly high charging rate.

[0006] To this end, the present invention proposes a charging device for connecting an electric energy storage device of a motor vehicle, in particular a car, with a charging station for electric energy, in particular, the motor vehicle is configured as a car, and the charging station is configured as a charging post of a charging infrastructure, for example. The charging device comprises a charging cable, which has at least one conductor, in particular copper, for conducting a charging current. In addition, the charging device according to the present invention comprises at least one connecting element, by which the charging cable can be connected to a corresponding connecting element between the electric storage device and the charging station. The charging cable can be configured as a charging cable in particular, and the at least one conductor is in particular a core of a cable. The connecting element is, for example, a charging socket, so that the corresponding connecting element is advantageously configured as a charging plug that fits into the charging socket. The motor vehicle is in particular an electrically operable motor vehicle having an electric motor, which can be supplied with energy by an electric energy storage device, in particular a traction battery and / or a high-voltage storage device. The connecting element is also referred to as a charging interface.

[0007] In order to be able to achieve particularly high charging speeds during the charging process of a motor vehicle, in which electrical energy flows from a charging station via a charging current to an electrical energy storage device of the motor vehicle, according to the invention, at least one latent heat accumulator is arranged on the charging line and / or on the at least one connecting element, by means of which the heat generated during the charging process can be absorbed. The latent heat accumulator is designed to store the heat supplied to the latent heat accumulator, in particular in a hidden, so-called latent manner. That is, the latent heat accumulator can absorb thermal energy without changing its own temperature at the same time. This is usually achieved in that the latent heat accumulator includes at least one phase change material, which changes its aggregate state and / or other phases when absorbing the supplied thermal energy, in particular by a phase change. According to the invention, the at least one latent heat accumulator is arranged on the charging line and / or on the connecting element, both of which generate heat, in particular, during the charging process.

[0008] In other words, the latent heat accumulator includes a phase change material that can absorb the emitted heat particularly advantageously, because the thermal energy is used to change the aggregate state of the phase change material. This prevents the phase change material from overheating and also prevents the actual copper wire or wire from overheating. The phase change material can only absorb a limited amount of heat, especially depending on its volume or the volume of the latent heat accumulator, according to the energy to be absorbed, which heat is released or can be released again, for example, after the charging process is completed. Here, in the charging device according to the present invention, the size of the latent heat accumulator can be determined, for example, according to the accumulator size or storage capacity of the electrical accumulator, and the storage capacity depends on the vehicle type of the motor vehicle. For example, for a small car, the storage capacity of the accumulator can be selected to be smaller than that of a mid-range car or a luxury car. Therefore, according to the present invention, the size of the latent heat accumulator can be determined in such a way that a high charging speed can be achieved particularly advantageously while using the material particularly advantageously. Therefore, the user of the motor vehicle can charge his motor vehicle within the desired time, and the desired time can be particularly short.

[0009] Since the latent heat accumulator can absorb heat without changing its own temperature, the reaching of a limit temperature of at least one component involved in the charging process, such as a connecting element, is delayed during the charging process, which results in the advantage that the charging speed can be kept particularly high or the charging time can be kept particularly short. Thus, passive cooling of the charging device can be achieved by means of the latent heat accumulator.

[0010] For example, particularly high charging currents can be used, which results in particularly short charging times, since power losses, in particular power losses at contact resistances, which can occur in particular between a connecting element and a corresponding connecting element, can be kept particularly low. Since the corresponding limiting temperature is reached particularly late, a premature reduction in power during the charging process can be avoided.

[0011] The invention is based on the following knowledge: For example, in a DC fast charger, the limiting temperature at the charging socket, which can be formed by the connecting element, reaches about 90 degrees Celsius, so that the charging process can last about ten minutes. Therefore, the invention focuses on conducting the generated heat away from the corresponding components, such as the charging socket, as quickly and evenly as possible and dissipating it to the environment, which is achieved by the charging device according to the invention, in particular in one embodiment, the charging cable and the connecting element are arranged between the charging station and the motor vehicle.

[0012] In an advantageous embodiment of the invention, the charging cable and the connecting element are components of the motor vehicle. That is, the charging device is integrated into the motor vehicle. In this case, for example, the charging cable connects the electrical energy storage device to a connecting element, in particular in the form of a charging socket, which is arranged, for example, on the outer skin of the motor vehicle. This results in the following advantage: the charging device is carried as a component of the motor vehicle independently of the charging station, so that to a certain extent any charging station can provide a particularly advantageous charging speed for the charging device according to the invention, for example by means of a software update.

[0013] In another advantageous embodiment of the invention, the charging cable and the connecting element are components of the charging station. In other words, the charging device is a component of the charging station, the charging cable being designed, for example, as a charging cable of the charging station, which has a connecting element at one end in the form of a charging plug, for example, in the form of a Type 2 plug, which can be plugged into a corresponding charging socket of a motor vehicle. This results in the following advantage: a charging device designed for passive cooling can be used for every electric vehicle to be charged by the charging station.

[0014] In another advantageous embodiment of the invention, the conductor is at least partially surrounded by an insulation, and a latent heat accumulator is arranged in at least one sub-region on the side of the insulation facing away from the conductor. In other words, the conductor or core passing through the insulation is configured as a cable, and a latent heat accumulator is arranged on the outside of the insulation, that is, outside the cable, at least in a sub-region. Here, the insulation is preferably made of rubber, especially silicone rubber, which has particularly good insulation properties, and the conductor or the charging cable, especially configured as a cable, has a particularly high flexibility. The conductor or core of the charging cable is preferably, for example, a copper cable, and the insulation surrounding the copper cable or the copper core conducts the heat generated by the charging process to the latent heat accumulator, so that the energy released by the heat can be stored in the latent heat accumulator and thus the reaching of the limit temperature of the charging cable or at least one connecting element adjacent to the charging cable can be delayed. This makes it particularly advantageous to achieve a high charging speed and thus a fast charging solution.

[0015] In another advantageous embodiment of the invention, the sub-region surrounds the conductor on the outer circumference in at least one direction and extends in the longitudinal extension direction of the charging cable. Here, the extension in the longitudinal extension direction can be short or long. In the case where the conductor of the charging cable has a substantially circular cross-section, for example, if the length in the longitudinal extension direction or the extension in the longitudinal extension direction is short, a substantially annular sub-region is produced. If the extension in the longitudinal extension direction is large, the latent heat accumulator is arranged around the conductor in a substantially hose-like manner. By surrounding at least one sub-region of the conductor with the latent heat accumulator, particularly effective cooling or keeping the temperature constant is achieved by the latent heat accumulator at least in this sub-region. If the latent heat accumulator is constructed so that it extends as long as possible over the entire length in the longitudinal extension direction, it is particularly advantageous to cool most of the charging cable. On the contrary, by constructing a plurality of annular sub-regions, for example, a particularly simple manufacture and / or a particularly high flexibility of the charging cable can be achieved through a series of annular elements.

[0016] In another advantageous embodiment of the invention, the sub-regions are interrupted by at least one partition wall, which in particular can also be made of the material of the conductor insulation. If the conductor has an approximately circular cross section, the at least one partition wall can be designed, for example, radially outwardly, so that, for example, a plurality of individual chambers can be realized along the conductor on the outer circumference by the partition wall, which can each be filled with a phase change material as a latent heat accumulator. By means of the at least one partition wall in the sub-region, for example, which interrupts the latent heat accumulator, for example, the mechanical properties of at least the charging cable of the charging device can be achieved particularly advantageously.

[0017] In another advantageous embodiment of the invention, the subregion with the latent heat accumulator extends helically around the at least one conductor. That is to say, the latent heat accumulator is wound helically around the at least one conductor, whereby the latent heat accumulator can be designed particularly simply, for example, while the latent heat accumulator can be arranged on a particularly large part of the conductor.

[0018] For the above-mentioned embodiments of the sub-areas along the conductor, when the charging cable comprises only one conductor, the sub-areas are respectively arranged around one conductor individually. In contrast, if the charging cable comprises multiple conductors, the above-mentioned embodiments or combinations thereof can be respectively implemented around a single conductor or can be implemented around multiple conductors in any combination, thereby achieving a particularly flexible design of the charging cable.

[0019] In another advantageous embodiment of the invention, the connection element is designed as a charging socket or a charging plug. In the first case, the corresponding connection element is designed as a charging plug, such as a Type 2 plug, and in the second case as a charging socket, which can be located, for example, in particular on a motor vehicle or on a charging station. The design as a charging socket and a charging plug makes it possible to realize a connection between the charging device and the motor vehicle or between the charging device and the charging station or between the motor vehicle and the charging station in a particularly simple and advantageous manner via the charging device.

[0020] In another advantageous embodiment of the invention, the latent heat accumulator is arranged on at least one contact element of the connecting element. In other words, the latent heat accumulator is connected, in particular thermally connected, to a contact element of the connecting element, which can be a contact pin of the charging plug, for example, in the case where the connecting element is designed as a charging plug. For example, in the case where the connecting element is designed as a charging socket, the contact element is, for example, a receiving socket corresponding to the contact plug or the contact pin. By placing or arranging the latent heat accumulator on the contact element of the connecting element, heat can be particularly advantageously absorbed, in particular at one of the locations where the maximum heat generation can be expected due to the contact resistance, so that one of the most thermally loaded areas of the charging device can be temperature-controlled or kept at a certain temperature by passive "cooling".

[0021] In another advantageous embodiment of the invention, the latent heat accumulator comprises at least one phase change material comprising paraffin and / or carbon. The phase change material of the latent heat accumulator is therefore at least partially made of paraffin. Additionally or alternatively, the phase change material is at least partially made of carbon. Here, for example, a temperature of about 55 degrees Celsius for the phase change for storing or absorbing latent heat can be achieved by paraffin, which can be particularly advantageous for charging devices. In addition, the combination of paraffin and carbon, which can thus form a composite of phase change material, can achieve a particularly advantageous thermal conductivity, for example, by the graphite contained, so that, for example, a particularly good thermal contact can be achieved between the components to be cooled, including the connecting elements and / or the charging cable, and the latent heat accumulator.

[0022] Further features of the invention are given by the drawings and the description of the drawings. The features and feature combinations mentioned in the above description and the features and feature combinations mentioned in the following description of the drawings and / or shown only in the drawings can be used not only in the respectively given combination but also in other combinations or can be used alone. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will now be described in detail with the aid of preferred embodiments and with reference to the accompanying drawings.

[0024] Figure 1 shows a schematic design of a charging device for connecting an electrical energy storage device of a motor vehicle to a charging station, the charging device having a charging cable and a connecting element;

[0025] Figure 2 shows a schematic structure of a connecting element of a charging device configured as a charging plug;

[0026] Figure 3 shows a schematic structure of a charging cable of a charging device; and

[0027] Figure 4 A cross-sectional view shows another specific embodiment of a charging cable of a charging device. DETAILED DESCRIPTION

[0028] Figure 1 The schematic structure of a charging device 10 for connecting an electrical energy storage device 14 of a motor vehicle 16 to a charging station 24 is shown, the charging device having a charging cable 12 and a connecting element 20. The charging cable 12 has at least one conductor 18, which is made in particular of copper and forms a cable core or a core of the charging cable 12, which is in particular designed as a charging cable. The conductor 18 serves to conduct the charging current. The charging device 10 also has at least one connecting element 20, by which the charging cable 12 can be connected to a corresponding connecting element 22 between the energy storage device 14 and the charging station 24.

[0029] In order to be able to carry out a charging process particularly quickly, i.e. at a particularly high charging rate, in which electrical energy is stored by means of a charging current from a charging station 24 into an electrical energy storage device 14 of a motor vehicle 16, at least one latent heat storage device 26 is provided on the charging line 12 and / or on the at least one connecting element 20, by means of which the heat generated during the charging process can be absorbed.

[0030] In this case, the charging cable 12 and the connecting element 20 are advantageously components of the motor vehicle 16, so that the connecting element 20 is advantageously, for example, Figure 1 The design shown is a charging socket, in particular a charging socket of a motor vehicle 16 .

[0031] In another embodiment of the invention, the charging cable 12 and the connecting element 20 can also each be a component of a charging station 24. As an alternative, the charging device 10 is neither a component of the motor vehicle 16 nor a component of the charging station 24, but is designed independently and is used for connection between the motor vehicle 16 and the charging station 24. In this case, the motor vehicle 16 is advantageously an electrically drivable passenger car and the charging station 24 can advantageously be designed, for example, as a charging post of a charging infrastructure element or, in simple cases, also as a conventional socket.

[0032] The at least one latent heat accumulator 26 comprises at least one phase change material containing paraffin and / or carbon. A phase change material is a material that changes its state of aggregation within a predetermined range, wherein energy, in particular energy in the form of supplied heat, does not contribute to an increase in the temperature of the phase change material, but serves to change the state of aggregation or other phases of the phase change material, so that despite the supply of heat, the phase change material and thus the latent heat accumulator 26 maintain their temperature. By means of paraffin, for example, a phase change temperature of approximately 55 degrees Celsius can be achieved, which is particularly advantageous for the charging process of the motor vehicle 16. If the phase change material additionally contains carbon, for example, its mechanical stability can be designed to be particularly advantageous.

[0033] Advantageously, a latent heat accumulator is provided at least on the contact element 28 of the connecting element 20. Figure 3 In the illustrated embodiment, the contact element 28 can be a contact pin if it is configured as a charging plug. Here, for example, it is also suitable to configure the charging plug as a compatible type 2 plug. Here, if the connecting element 20 is configured as a charging socket, the corresponding connecting element 22 can be configured as a plug, and vice versa.

[0034] Figure 2 An embodiment of a charging device 10 is shown in which a connecting element 20 is designed as a charging plug, on which a latent heat accumulator 26 is arranged.

[0035] Figure 3 The charging cable 12 of the charging device 10 is shown, which is designed approximately in the form of a cable, so that the conductor 18 is in particular a copper core forming the cable-shaped charging cable. As a result, the charging current can be conducted particularly advantageously. The conductor 18 is surrounded by an insulation 30, which in turn can be surrounded by a filling material 32 and a shielding braid 34 in this embodiment, and finally an outer insulation 36. In this regard, the charging cable 12 shown can be designed as a conventional cable, which can be provided with a latent heat accumulator 26 and an additional further outer insulation 38 later by means of a retrofit solution, for example. As a result, the charging cable 12 can be manufactured in a particularly advantageous manner, in particular at low cost. Advantageously, the insulation 30 and the outer insulation 36 as well as the further outer insulation 38 are each made of silicone rubber, which can ensure particularly good electrical insulation properties while ensuring the flexibility of the charging cable 12.

[0036] therefore, Figure 3The charging cable shown in FIG is designed such that the conductor 18 is at least partially surrounded by an insulation 30, and a latent heat accumulator 26 is arranged in at least one subregion on the side of the insulation facing away from the conductor 18. In this case, the subregion of the conductor 18 is designed such that it surrounds the conductor 18, which is in particular circular, on the circumference in at least one direction, i.e., it is designed in a ring-shaped or hose-shaped manner around the conductor, and it is designed in a ring-shaped or rod-shaped manner depending on its extension in the longitudinal extension direction 40 of the charging cable 12. As an alternative, the subregion is neither hose-shaped nor ring-shaped, but is designed in a spiral shape around the conductor 18.

[0037] Figure 4 A cross-section through a charging cable 12 is shown in another embodiment, in which it can be seen that the subregion forming the latent heat accumulator 26 is designed in an annular manner around the conductor 18, which subregion can be interrupted by a partition wall 42, so that, for example, a plurality of individual chambers 44 of the latent heat accumulator 26 are formed. The latent heat accumulator can thus be designed to be particularly mechanically stable, for example.

[0038] The charging cable 12 with its copper wire as the actual current conductor is provided with an insulation 30 which is in particular liquid-tight and in particular made of rubber or silicone rubber. The insulation is surrounded by a phase-change material which essentially forms a latent heat accumulator 26, the thickness of which or the volume of which can be varied depending on the charging concept or the size or capacity of the electrical energy storage device 14 to be filled in the motor vehicle 16. If, for example, the charging speed is to be particularly high due to a particularly large capacity of the electrical energy storage device 14, the volume and the heat absorption capacity of the latent heat storage device 26 can be selected accordingly.

[0039] Finally, the latent heat accumulator 26 is surrounded by further insulation of the outer insulation 38. The advantages of a latent heat accumulator 26 arranged in this way are a particularly compact design and a simple construction.

[0040] As already mentioned, the possibility of particularly simple production of the charging cable 12 for the charging device 10 is provided by encapsulating existing cables with the latent heat accumulator 26. In particular, the latent heat accumulator 26 can also be arranged on the connecting element 20 in such a way that the corresponding connecting element 22 can be particularly advantageously used, for example, in existing charging infrastructures, whereby, for example, the acquisition costs of the charging device 10 can be particularly low.

[0041] Overall, the charging device 10 shown has the following advantages: Due to the delayed reaching of the limiting temperature of the connection element 20, for example, the charging time can be kept particularly short. In addition, a particularly fast charging scheme can be implemented by the charging device 10. In addition, components of the existing charging infrastructure can continue to be used, since, for example, no or only minor changes to corresponding basic components, such as the corresponding connection element 22, are required.

[0042] Reference numerals list

[0043] 10 Charging device

[0044] 12 Charging cable

[0045] 14 Electrical accumulator

[0046] 16 Motor Vehicles

[0047] 18 Wire

[0048] 20 Connecting elements

[0049] 22 Corresponding connection elements

[0050] 24 Charging Stations

[0051] 26 Latent heat storage

[0052] 28 Contact elements

[0053] 30 Insulation

[0054] 32 Filling material

[0055] 34 Shielding Braid

[0056] 36 External insulation

[0057] 38 Additional external insulation

[0058] 40 Longitudinal extension direction

[0059] 42 Divider Wall

[0060] 44 Chamber

Claims

1. A charging device (10) for connecting an electrical energy storage device (14) of a motor vehicle (16) to a charging station (24) for electrical energy, the charging device comprising a charging cable (12) and at least one connecting element (20), the charging cable having at least one conductor (18) for conducting a charging current, the charging cable (12) being connectable via the connecting element to a corresponding further connecting element (22) between the energy storage device (14) and the charging station (24), characterized in that: At least one latent heat accumulator (26) is arranged on the charging cable (12) and / or on the at least one connecting element (20), by means of which heat generated during the charging process can be absorbed. The latent heat accumulator is able to absorb thermal energy without changing its own temperature. The conductor (18) is at least partially surrounded by an insulation (30), the latent heat accumulator (26) being arranged in at least one subregion on a side of the insulation facing away from the conductor. The sub-region surrounds the conductor (18) on the outer circumference in at least one direction and extends in the longitudinal extension direction of the charging cable (12), The subregion forming the latent heat storage device (26) is designed in an annular manner around the conductor (18). Construct multiple annular sub-regions, and The sub-regions are interrupted by at least one partition wall (42), and the partition wall is designed radially outward from the insulation (30), so that a plurality of individual chambers (44) of the latent heat accumulator (26) are formed on the outer circumference by the partition wall, each of which can be filled with a phase change material.

2. The charging device (10) according to claim 1, characterized in that: The charging cable (12) and the connecting element (20) are components of a motor vehicle (16).

3. The charging device (10) according to claim 1, characterized in that: The charging cable (12) and the connecting element (20) are components of a charging station (24).

4. The charging device (10) according to any one of claims 1 to 3, characterized in that: The partial region extends helically around the at least one conductor (18).

5. The charging device (10) according to any one of claims 1 to 3, characterized in that: The connecting element (20) is designed as a charging socket or a charging plug.

6. The charging device (10) according to any one of claims 1 to 3, characterized in that: The latent heat accumulator (26) is arranged on at least one contact element (28) of the connecting element.

7. The charging device (10) according to any one of claims 1 to 3, characterized in that: The at least one phase change material of the latent heat accumulator (26) comprises paraffin and / or carbon.

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