Charging plug connector for electric and hybrid vehicle

Abstract

The invention relates to a charging plug connector (1) for electric and hybrid vehicles (18), comprising a charging contact (2) and at least one heat reservoir (5) having a housing (6), the heat reservoir (5) being in heat-conducting contact with the at least one charging contact (2) such that heat can be conducted from the charging contact (2) to the heat reservoir (5), a fluid and a phase change material enclosed in at least one capsule (8) having an insoluble capsule shell are arranged in the housing (6). In this way, an improved heat dissipation is achieved in the charging plug connector (1) which is not equipped with itself a cooling system from the charging station side.

Description

Technical Field

[0001] The present invention relates to a charging connector / charging plug for electric vehicles and hybrid vehicles, the charging connector including charging contacts and at least one heat storage device having a housing, wherein the heat storage device is in thermally conductive contact with at least one charging contact. Background Technology

[0002] Electric and hybrid vehicles have rechargeable energy storage devices, typically high-voltage batteries, which provide energy to the electric drive system during operation. These high-voltage batteries have a limited energy storage capacity, necessitating periodic recharging at charging stations. Battery charging is achieved via a charging cable between the charging station and the vehicle. This cable, for example, according to European standard IEC 62196 Type 2, has a charging plug on one side that can be inserted into a charging socket at the charging station, and a charging connector on the other side that can connect to a built-in charging plug installed in the electric or hybrid vehicle. In this document, the charging socket, charging plug, charging connector, and built-in charging plug are all covered by the term "charging connector." The charging socket and charging connector have contact sleeves as charging contacts, and the charging plug, as well as the built-in charging plug installed in the electric or hybrid vehicle, have contact pins that can be inserted into the contact sleeves as charging contacts.

[0003] As described, for example, in EP 3 043 421 A1, the charging connector heats up due to ohmic current heat loss as the charging current flows through it. However, regulations require that the heating of the charging connector be limited to a temperature rise limit. Therefore, for example, according to standard IEC 62196-3, the temperature rise limit is limited to 50 K. This, in turn, means that with the connector geometry largely standardized, the maximum charging current under continuous load operation typically cannot exceed 200 A. However, in the case of intermittent charging of batteries in electric or hybrid vehicles, a higher charging current needs to be provided within a limited time to charge the battery for the expected short period. This causes the charging connector to briefly heat up beyond the temperature rise limit. Because the connector geometry is standardized, and the amount of conductive material used in the electrical connector, typically copper, should be as small as possible, the conductive cross-section of the electrical connector cannot be arbitrarily increased.

[0004] According to EP 3 043 421 A1, an electrical connector is provided that can increase the charging current while limiting heat generation, and thus has improved short-time current carrying capacity. To this end, an electrical connector for a charging plug or charging socket is proposed, wherein the connector has a first connection region for current connection with a power receiver and a second connection region for current connection with a power source, wherein the connector is designed to have a cooling fluid channel constructed therein, wherein the cooling fluid channel of the connector is fluidly connected to a cooling fluid source arranged in a charging station.

[0005] Cooling the charging connectors for electric and hybrid vehicles from the charging station side is also well known in the prior art. DE 10 2015 119 338 A1 describes two connection points for coolant lines arranged on the contact sleeve element of the charging plug. Coolant is guided to circulate around the contact sleeve element by means of a spiral sleeve element. The two connection points serve as the inlet and outlet for coolant guided from the charging station to the charging plug. EP 3 433 902 B1 similarly describes a connector component with cooled contact elements. It also specifies that coolant is guided from the charging station side to the contact element of the charging socket connected to the charging cable via coolant lines. A fluid is used as the coolant, which is introduced perpendicularly into the hollow contact element and flows back within the contact element.

[0006] Finally, 10 2016 105 361 B4 also describes a plug connector component with cooled contact elements, wherein, it is also specified here, coolant is guided to the contact elements of the charging socket connected to the charging cable via coolant lines on the charging station side. Here, guide elements are arranged on the contact elements, which should ensure that the contact elements are circulated with coolant in the form of compressed air.

[0007] However, some solutions are also known from the prior art that can be applied to charging connectors that are not directly cooled from the charging station side, such as charging connectors installed in the body of electric or hybrid vehicles, such as built-in charging plugs according to European standard IEC 62196 Type 2.

[0008] DE 10 2016 107 409 A1 describes a plug connector assembly for connection with a mating plug connector assembly. The plug connector assembly includes a housing having a plug section for mating with the mating plug connector assembly and contact elements disposed on the plug section for electrical contact with corresponding mating contact elements of the mating plug connector assembly. Additionally, a heat-conducting element coupled to the contact elements and a heat sink disposed within the housing are provided, the heat sink being thermally connected to the contact elements via the heat-conducting element to dissipate heat from the contact elements. In this way, a plug connector assembly with contact elements is provided, which can have a large current-carrying capacity, for example, for use in a charging system for charging electric vehicles.

[0009] Furthermore, DE 20 2019 102 461 U1 describes a plug connector assembly for connection with a mating plug connector assembly, comprising: a housing; a plug portion disposed on the housing for plugging with the mating plug connector assembly; an electrical contact element disposed on the plug portion for transmitting current between the plug connector assembly and the mating plug connector assembly; and a cooling element disposed on the contact element for cooling the contact element, wherein a ventilation device for generating airflow on the cooling element is provided. However, the plug connector assembly and the system described in DE 10 2016 107 409 A1 are very complex. Summary of the Invention

[0010] Based on the above background, the object of the present invention is to achieve improved heat dissipation in a charging connector that is not equipped with a cooling system from the charging station side.

[0011] This objective is achieved through the subject matter of the independent claims. Preferred improvements to the invention are described in the dependent claims.

[0012] Therefore, according to the present invention, a charging plug connector for electric vehicles and hybrid vehicles is provided, the charging plug connector comprising a charging contact and at least one heat storage device having a housing, wherein the heat storage device is in thermally conductive contact with at least one charging contact, thereby enabling heat to be conducted from the charging contact to the heat storage device, wherein a fluid is disposed in the housing and a phase change material is encapsulated in at least one capsule having an insoluble shell.

[0013] In this article, the heat storage device mentioned refers to a heat storage device provided as an additional component with the charging connector, whose sole purpose is to absorb and store the heat generated during charging. In particular, the heat storage device can store this heat better than the charging contacts themselves, thereby delaying the heating of other parts of the charging connector.

[0014] The key point of this invention is that at least one capsule containing a phase change material is arranged in a heat storage device, the capsule being surrounded by a fluid. Through the fluid, heat is absorbed and stored from the charging contacts on the one hand, and on the other hand, the heat absorbed by the fluid is uniformly transferred to the capsule. Preferably, the capsule is a spherical container. For this purpose, the capsule has an insoluble, heat-conducting shell, within which the phase change material is arranged. In this context, "insoluble" means that the shell remains in the fluid and does not chemically react with the fluid in a way that would cause the shell to dissolve.

[0015] A latent heat storage device is formed within a capsule by utilizing a phase change material (PCM) based on the enthalpy of the thermodynamic state change of the heat storage medium. The principle used in this paper is the utilization of a solid-to-liquid phase transition, i.e., a transition from a condensed to a molten state. For this purpose, the heat storage device incorporates a PCM. A PCM is a material that can release or absorb heat or cold during its phase transition, depending on its melting point and ambient temperature.

[0016] The energy stored in the temperature range of a phase change material is significantly greater than the energy absorbed during heating within the same temperature range without a phase change. In the case of heating without a phase change, the energy absorbed is determined solely by the specific heat capacity of the material. Therefore, phase change materials offer advantages in terms of heat storage density, especially when the temperature difference is small.

[0017] If a phase change material is heated to near its melting point, the heat absorbed by the material is used to complete the phase transition. Therefore, the temperature does not rise during the transition from solid to liquid. Once the material is completely liquid, it continues to heat up as it did before the phase transition.

[0018] Because the phase change material does not continue to heat up during the phase transition period, the temperature rise is delayed compared to a temperature rise without a phase transition. This is fully utilized according to the invention so that the temperature at the charging contacts, which are in thermal contact with the heat storage device, is kept as low as possible. In this way, the time until the critical temperature at which the charging process must be interrupted can be extended during the charging process.

[0019] Now, importantly, the capsule is equipped with an insoluble shell. This prevents the liquid phase change material from leaking into and mixing with the fluid. Therefore, the phase change is reversible.

[0020] The heat storage unit can be designed integrally with the charging contacts, allowing heat to be absorbed within the charging contacts themselves. Alternatively, the heat storage unit can thermally surround the charging contacts to facilitate heat dissipation during charging. It can also be specified that the charging contacts are thermally connected to the heat storage unit using a thermally conductive element. Here, the thermally conductive element is understood to be an element that, in the charging connector according to the invention, improves the thermal conductivity between the charging contacts connected to the thermally conductive element and the heat storage unit, which is also connected to the thermally conductive element, compared to the absence of the thermally conductive element. Therefore, the installation of the thermally conductive element improves the ability to conduct heat generated on or within the charging contacts to the heat storage unit.

[0021] In principle, the capsule can be formed from different materials. However, according to a preferred embodiment of the invention, the capsule shell comprises a metallic material. Particularly preferred is that the capsule shell comprises copper. Metallic materials generally have high thermal conductivity. Copper, in this case, has particularly high thermal conductivity. However, it is also possible that the metallic material also comprises other mixtures, such as nickel or silver, by means of which the thermal conductivity can be further improved.

[0022] Of course, the capsule can also be made of plastic. Plastic also has good thermal conductivity, but is lighter than metal. Therefore, depending on the requirements of the charging connector, a capsule with a plastic shell can be configured, for example, to reduce weight.

[0023] In this document, according to a preferred embodiment of the invention, the heat storage device is provided with a plurality of capsules, wherein the capsules are arranged as granules within a shell, and fluid flows around the capsules. Regarding the material composition, the granules may have capsules whose shells comprise both plastic and metallic materials.

[0024] The capsules are preferably shaped such that gaps are formed between the capsules in the heat storage unit, and the fluid is placed in these gaps. Due to the thermal effect and the resulting change in fluid density, a flow that causes the fluid to move is formed, so that the fluid flows in the gaps formed by the capsules and thus flows around the capsules. As a result, better heat distribution is achieved in the heat storage unit, thereby making the capsules heated evenly.

[0025] In principle, capsules can have different diameters. However, according to a preferred improvement of the invention, the diameter of the capsule is specified to be between 2 mm and 5 mm. Therefore, the granules exist as microparticles. By reducing the capsule size, the phase change material within the capsule heats up more uniformly. Simultaneously, the diameter is chosen such that the ratio of the capsule shell to the phase change material in a single capsule ensures that the granules have a high heat storage capacity.

[0026] In principle, fluids can be composed of different substances. However, according to a preferred embodiment of the invention, the fluid is oil or a mixture of water and ethylene glycol. The oil can be, for example, mineral oil, vegetable oil, or silicone oil.

[0027] However, this document may also specify that the fluid is another phase change material (PCM) with a melting temperature lower than that of the stated PCM. Therefore, the capsule is first embedded within and surrounded by this other PCM. During charging, the heat storage unit absorbs heat conducted from the charging contacts, and the other PCM becomes heated. Here, the heat-conducting shell of the capsule acts as a heat-conducting element within the heat storage unit itself, and helps to uniformly heat the other PCM. If the other PCM eventually becomes liquid, this liquid PCM circulates, thereby enabling uniform heating of the PCM within the capsule.

[0028] The present invention also relates to the application of the system described above in the body of an electric vehicle or a hybrid vehicle.

[0029] The present invention also relates to a system comprising the charging connector as described above and a corresponding charging connector having a corresponding charging contact, wherein the corresponding charging connector is provided with a heat dissipation element that can be loaded by a cooling fluid, the corresponding charging contact of the corresponding charging connector is designed as a contact sleeve, and the charging contact of the charging connector, designed as a contact pin, can be inserted into the contact sleeve.

[0030] When referring to a corresponding charging connector in this document, it means, on the one hand, a charging connector with the same mating surfaces as the charging connector. However, in this case, if one mating surface has contact pins, the other mating surface has contact sleeves, and vice versa. Therefore, a kit consisting of a charging connector and a corresponding charging connector can be mated together. On the other hand, the term "corresponding charging connector" also applies in this document to cases where the mating surfaces only partially correspond in the above sense—that is, the corresponding charging connector does not have all the contacts present in the charging connector, for example—but the existing contacts of the corresponding charging connector correspond to those of the charging connector in terms of mating surfaces. In this case, the charging connector and the corresponding charging connector can still be mated together.

[0031] This situation exists, for example, in charging connectors for DC charging that are connected to charging cables according to European standard IEC 62196 Type 2. Such charging connectors can be inserted into built-in charging plugs installed in the body of electric or hybrid vehicles and suitable for both AC and DC charging. In this DC charging connector, only communication and protection contacts exist in the AC plug face, but no contacts for the outer conductor and neutral conductor used for AC charging.

[0032] Here, the conductor referred to as the outer conductor (also commonly known as the phase conductor) is a conductor that is energized during normal operation and facilitates the transmission or distribution of electrical energy, but is not a neutral conductor. The neutral conductor is the conductor electrically connected to the neutral point and facilitates the distribution of electrical energy. In European Standard IEC 62196 Type 2, contacts currently referred to as AC charging contacts are marked L1, L2, and L3 (outer conductors) and N (neutral conductor), while DC charging contacts are marked DC+ and DC-. This understanding should not contradict the fact that European Standard IEC 62196 Type 2 also recognizes the operating mode of DC charging via contacts L1, L2, L3, and N.

[0033] Preferably, the system is designed to further include a charging station and a charging cable connected to the charging station and carrying a corresponding charging connector. The charging station has a cooling fluid source, and the charging cable is equipped with cooling fluid conduits to deliver cooling fluid from the cooling fluid source to the heat dissipation element of the corresponding charging connector and then back. Here, the cooling fluid source of the charging station is designed to allow the heated cooling fluid guided back from the charging connector to be cooled again, so that it can be reused for cooling. Attached Figure Description

[0034] The invention will now be described in more detail with reference to the accompanying drawings and preferred embodiments.

[0035] The diagram shows:

[0036] Figure 1 A perspective view shows a charging connector according to a preferred embodiment of the invention.

[0037] Figure 2 Showing with Figure 1 The corresponding plug connector in the diagram.

[0038] Figure 3a The arrangement of the charging contacts and the heat storage tank is schematically shown in a cross-sectional view.

[0039] Figure 3b Another arrangement with charging contacts and a heat storage tank is schematically shown in cross-sectional view.

[0040] Figure 4 A system according to a preferred embodiment of the present invention is schematically shown, the system including a charging plug connector, a corresponding charging plug connector, a charging cable, a charging station, and a cooling system. Detailed Implementation

[0041] from Figure 1 A perspective view of a charging connector 1 according to a preferred embodiment of the present invention can be seen in the diagram. Here, the charging connector is for installation in an electric vehicle or hybrid vehicle 18 (as schematically shown in...). Figure 4 The built-in charging plug is located in the body 17 (as shown in the figure). The current charging connector 1 is essentially a built-in charging plug of European standard IEC 62196 type 2 in terms of its mating surface. In addition to AC charging contacts, protection contacts and communication contacts which are not otherwise marked, the charging connector 1 also has two DC charging contacts 2 for DC charging.

[0042] Charging connector 1 can be used with Figure 2 The corresponding charging connector 4 shown is connected. Here, the corresponding charging connector is a charging connector that can be fastened to the charging cable and can be plugged into the built-in charging plug. The charging connector shown here is an exemplary charging connector for DC charging and therefore has corresponding DC charging contacts 3, protection contacts, and communication contacts. Not only the built-in charging plug shown here, but also the connector shown here conforms to the European standard IEC 62196 in terms of its mating surfaces.

[0043] Figure 3a The charging contact 2 together with the heat storage unit 5 is now shown in cross-section. The heat storage unit 5 has a housing 6 that thermally surrounds the charging contact 2. A fluid is contained within the housing 6 of the heat storage unit 5 and flows around a capsule 8. The fluid is a mixture of water and ethylene glycol. The capsule 8 is equipped with an insoluble shell that encapsulates the phase change material and thus separates the phase change material from the fluid. Therefore, the phase change material can change its phase in a reversible process without flowing into the fluid.

[0044] Figure 3b Another arrangement according to the invention, including the charging contact 2 and the heat storage tank 5, is shown. Currently, the heat storage tank 5 is designed integrally with the charging contact 2. The housing 6 of the heat storage tank 5 is formed by two interlocking parts of the charging contact 2. Similar to... Figure 3a The arrangement includes fluid within the shell 6 and capsule 8.

[0045] As mentioned above, the charging connector 1 with a built-in plug is used on the body 17 of an electric or hybrid vehicle 18. For this information, please refer to... Figure 4 , Figure 4A system according to a preferred embodiment of the present invention is schematically illustrated. The system includes a charging connector 1 installed in the body 17 of an electric or hybrid vehicle 18, a corresponding charging connector 4, a charging station 20, and a charging cable 21 connected to the charging station 20 and carrying the corresponding charging connector 1. Importantly, in this preferred embodiment of the invention, the corresponding charging connector 4 is provided with a heat dissipation element 19 that can be loaded with cooling fluid for cooling the corresponding charging contacts 3. To achieve cooling of the corresponding charging contacts 3 via the heat dissipation element 19, the charging station 20 is provided with a cooling fluid source 14, and the charging cable 21 has a cooling fluid conduit 22 to deliver cooling fluid from the cooling fluid source 14 to the heat dissipation element 19 of the corresponding charging connector 4 and back.

[0046] Since the charging connector 1 installed in the body 17 of the electric vehicle or hybrid vehicle 18 is now engaged with the corresponding charging contact 3 on the charging station side during charging, the heat generated during charging is absorbed in the heat storage tank 5. Furthermore, with both charging connectors 1 and 4 in the plugged-in state, the heat is cooled by the cooling system on the charging station side through thermal coupling between the charging connector 1 installed in the body 17 of the electric vehicle or hybrid vehicle 18 and the corresponding charging connector 4 installed on the charging cable 21. Thus, the active cooling of the corresponding charging connector 4 using cooling fluid from a cooling fluid source can also indirectly cool the charging connector 1 installed in the body 17 of the electric vehicle or hybrid vehicle 18.

[0047] List of reference numerals in the attached diagram:

[0048] 1 Charging connector

[0049] 2 Charging contacts

[0050] 3. Corresponding charging contacts

[0051] 4. Corresponding charging connector

[0052] 5. Thermal storage unit

[0053] 6. Shell

[0054] 8 capsules

[0055] 14 Cooling fluid source

[0056] 17. Body

[0057] 18 Electric or hybrid vehicles

[0058] 19 Heat dissipation components

[0059] 20 charging stations

[0060] 21 Charging cable

[0061] 22 Cooling fluid piping

Claims

1. A charging connector (1) for electric vehicles and hybrid vehicles (18), the charging connector comprising charging contacts (2) and at least one heat storage device (5) having a housing (6), wherein, The heat storage unit (5) is in thermal contact with at least one charging contact (2), thereby enabling heat to be transferred from the charging contact (2) to the heat storage unit (5). A fluid and a phase change material are arranged in the shell (6) and encapsulated in at least one capsule (8) with an insoluble shell.

2. The charging connector (1) according to claim 1, wherein, The capsule contains a metallic material.

3. The charging connector (1) according to claim 1, wherein, The capsule shell is made of plastic material.

4. The charging connector (1) according to any one of the preceding claims, wherein the charging connector has a plurality of capsules (8), wherein, The capsule (8) is arranged as granules in the shell (6), and the fluid flows around the capsule (8).

5. The charging connector (1) according to any one of the preceding claims, wherein, The diameter of the capsule (8) is between 2 mm and 5 mm.

6. The charging connector (1) according to any one of the preceding claims, wherein, The fluid is either oil or a mixture of water and ethylene glycol.

7. The charging connector (1) according to any one of claims 1 to 5, wherein, The fluid is another phase change material, the melting temperature of which is lower than that of the phase change material.

8. The application of the charging connector according to any one of the preceding claims on the body (17) of an electric vehicle or hybrid vehicle (18).

9. A system comprising a charging connector (1) according to any one of claims 1 to 7 and a charging connector (4) corresponding to the charging connector and having a corresponding charging contact (3), wherein, The corresponding charging connector (4) is equipped with a heat dissipation element (19) that can be loaded by cooling fluid. The corresponding charging contact (3) of the corresponding charging connector (4) is designed as a contact sleeve. The charging contact (2) of the charging connector (1) is designed as a contact pin that can be inserted into the contact sleeve.

10. The system according to claim 9, further comprising a charging station (20) and a charging cable (21) connected to the charging station (20) and carrying a corresponding charging connector (4), wherein, The charging station (20) has a cooling fluid source (14) and the charging cable (28) is equipped with a cooling fluid pipeline (22) so as to deliver the cooling fluid from the cooling fluid source (14) to the heat dissipation element (19) of the corresponding charging plug connector (4) and back again.

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