Charging plugs, charging cables, charging systems and procedures for electrically charging an electric vehicle

Abstract

The invention relates to a charging plug for electrically charging an electric vehicle, in particular for transmitting high power, with at least one power contact (16), preferably two power contacts (16) for conducting electrical energy. The charging plug is characterized in that a cooling system with a cooling fluid is provided for cooling the at least one power contact (16). Furthermore, a charging cable, a charging system, and a method for electrically charging an electric vehicle are described.

Description

[0001] The invention relates to a charging plug for electrically charging an electric vehicle according to the preamble of claim 1. Furthermore, the invention relates to a charging cable or charging line for electrically charging an electric vehicle according to the preamble of claim 11. The invention also relates to a charging system comprising a charging plug and a charging cable according to the preamble of claim 13. Finally, the invention relates to a method for electrically charging an electric vehicle according to the preamble of claim 15.

[0002] The number of electric vehicles sold and used is increasing. The charging infrastructure for the built-in rechargeable batteries is currently being expanded. Power supply units in the form of charging stations are used to charge the vehicles. The charging current is transmitted to the vehicles via charging cables. Charging plugs, located on the charging cables, are used to connect the vehicles. Standardized plugs can be used, such as the EN 62196 Type 2 plug standardized in the European Union. However, other charging plug systems are also conceivable.

[0003] To enable the fastest possible charging of vehicle batteries, high current flows towards the vehicle are required. However, high currents generally lead to increased heating of the components involved. Accordingly, initial approaches have been pursued towards cooling charging plugs. Electrically insulating cooling media have been used to ensure electrical safety. However, this results in considerable complexity in handling and operation, as well as significant costs.

[0004] It is therefore an object of the invention to eliminate these disadvantages. In particular, suitable cooling of the charging plug is to be achieved. The temperatures in the charging plug and / or at the power contacts are to be reduced. This should, in particular, make it possible to reduce the required cross-sections of the conductors.

[0005] A charging plug with the features of claim 1 solves this problem. The charging plug is used for electrically charging an electric vehicle. This can be, in particular, a passenger car. The charging plug should be especially suitable for transmitting high power. It is equipped with at least one power contact, preferably two power contacts, for conducting electrical energy. The charging plug is characterized by the fact that a cooling system with a cooling fluid is provided for cooling the at least one power contact. In this way, the waste heat can be dissipated. Furthermore, the cross-sections of the power conductors and contacts can potentially be reduced. Thus, the transmission of high charging power with a small copper cross-section is made possible by liquid cooling of the contacts and the charging cable.

[0006] The cooling system includes at least one heat sink. Preferably, the at least one heat sink is fluid-permeable, and preferably its housing is as well. This ensures efficient heat transfer. The waste heat can thus be dissipated from the area by the cooling fluid.

[0007] The at least one heat sink is preferably assigned to the at least one power contact. Preferably, it is in contact with this contact. Preferably, each of the multiple power contacts is assigned one of the heat sinks. Particularly preferably, each of the power contacts is assigned a separate heat sink. In this way, good cooling of each power contact is achieved. Furthermore, electrical insulation can be achieved or improved by separation.

[0008] Preferably, the at least one heat sink is thermally contacted and / or connected to the at least one power contact or one of the power contacts. The contact and / or connection is preferably thermally conductive. In this way, good heat transfer is achieved. Optionally

[0009] The cooling fluid is electrically insulated from the at least one power contact. In particular, the cooling fluid is conducted in an electrically insulated manner. Preferably, electrical insulation is provided, more preferably as an insulating layer, especially between the cooling fluid and the power contact. In this way, electrical safety is achieved.

[0010] In particular, the at least one heat sink, and especially its housing, is electrically insulating. Preferably, the at least one heat sink, and especially its housing, is made of an electrically insulating material, particularly a plastic. An electrically non-conductive material is particularly suitable to ensure electrical safety.

[0011] A liquid can preferably be used as the cooling fluid. The liquid can, in particular, be electrically conductive. Preferably, water can be used as the cooling fluid. This allows for the provision of a cost-effective and generally available cooling fluid as the cooling medium.

[0012] Preferably, the at least one heat sink has at least one internal cooling fluid channel for conveying the cooling fluid. More preferably, this cooling fluid channel is meandering. The at least one cooling fluid channel extends, preferably, over almost the entire surface of the at least one heat sink. This ensures good heat dissipation.

[0013] The charging plug is provided with at least two connections for cooling fluid lines, particularly hose lines. Preferably, at least one of the cooling fluid lines serves as the cooling fluid supply line or flow line, and at least one of the cooling fluid lines serves as the cooling fluid return line or discharge line. The connections are specifically linked to the end sections of the respective cooling channels. This ensures the safe transport of the cooling fluid.

[0014] The at least one heat sink is preferably composed of several parts, in particular at least one upper part and at least one lower part. The parts are preferably permanently connected to one another, preferably bonded or welded together. This prevents the escape of cooling fluid.

[0015] The object of the invention is further achieved by a charging cable or charging line for electrically charging an electric vehicle with the features of claim 11. The charging cable is particularly suitable for transmitting high power. It has a cable sheath and at least two electrical conductors, preferably power conductors, running through the cable sheath for transmitting electrical energy. Furthermore, a charging plug, particularly as described above, is provided with at least two power contacts connected to the power conductors for transmitting electrical energy to the electric vehicle. The charging cable is characterized by the fact that a cooling system with a cooling fluid is provided for cooling the at least two power contacts and / or the power conductors. This allows for improved heat dissipation.

[0016] Preferably, at least two cooling fluid lines are provided within the cable sheath. These preferably serve to supply and / or remove cooling fluid for cooling the power contacts. In particular, a cooling circuit is provided. A cooling circuit enables particularly simple and, in particular, efficient cooling. In a preferred embodiment, at least one control wire is provided within the cable sheath, preferably for exchanging control signals and / or for data transmission. This allows for control of the charging process and / or the cooling.

[0017] Furthermore, the object of the invention is achieved by a charging system with the features of claim 13. The charging system comprises a charging plug, particularly as described above, and a charging cable, particularly as described above. The latter serves to connect the charging plug to a power supply unit, in particular a charging station. A charging coupling corresponding to the charging plug is also provided on the electric vehicle to be charged in order to transfer electrical energy between the power supply unit and the electric vehicle. A cooling system with fluid cooling is provided for cooling at least one power contact of the charging plug. This ensures safe and simple operation.

[0018] Cooling fluid lines can run through the charging cable, particularly parallel to the power lines. Preferably, the cable and / or the electrical conductors within it can also be cooled. The power supply unit, especially the charging station, preferably includes a cooling circuit for the cooling fluid. A pump device can preferably be provided, with the cooling circuit running through the charging cable to the charging plug. This ensures stable operation of the cooling system.

[0019] The problem is further solved by a method for electrically charging an electric vehicle with the measures of claim 15. The method is particularly suitable for transmitting high power. A charging plug is provided, especially according to the above descriptions, with at least two power contacts for conducting electrical energy. The method is characterized in that the at least two power contacts are cooled with a cooling fluid. This allows the temperature in the charging plug to be reduced even at high current flows.

[0020] The power contacts can preferably be cooled by means of fluid-cooled heat sinks. Preferably, a cooling circuit for the cooling fluid is routed through the charging cable, in particular through coolant lines. The cooling circuit can be operated, in particular during the charging process and / or depending on measured values, especially temperature-controlled. A cooling circuit is a particularly manageable method of cooling. This ensures reliable operation at high power levels.

[0021] Preferred embodiments of the invention are described in more detail below with reference to the figures in the drawing. This drawing shows: Fig. 1 a charging plug according to the invention for an electric vehicle, Fig. 2 a cross-section through a charging cable for charging an electric vehicle, Fig. 3 a perspective view of one of the performance contacts of a first embodiment of the invention, Fig. 4 an exploded view of the heat sinks of the exemplary embodiment of the Fig. 3, Fig. 5 a perspective view of a second embodiment of a charging plug with round contacts, and Fig. 6 an exploded view of the exemplary embodiment of the Fig. 5.

[0022] In the Fig. Figure 1 shows a perspective view of a charging plug 10. The charging plug has a housing 11 in which the electrical components are located.

[0023] A handle 12 allows a person to handle the charging plug 10. A charging cable 13 is indicated in the lower part of the housing 11. In this case, the charging cable 13 is permanently connected to the charging plug 10. The other end of the charging cable 13 is not shown here. It is usually permanently, or alternatively detachably, connected to a power supply unit or a charging station. The latter are also not shown here.

[0024] The charging plug 10 has its electrical contacts opposite the handle 12. In the illustrated embodiment, two plug elements 14 and 15 are provided. This is an example of a plug type that has been defined by the European Commission as a standard in the IEC 62196-1 standard as plug type EN 62196 Type 2.

[0025] This connector type exists in various versions, each with a different design depending on the charging current. The example shown is a Type 2 connector for high-voltage direct current applications. In this case, the lower connector element 15 has two power contacts 16. These power contacts 16 are used to conduct direct current with high voltages and high currents.

[0026] In the upper part of the charging plug 10, specifically in the area of ​​the plug element 14, three contacts are shown. These are the protective earth contact 17 and two control conductor contacts 18. The protective earth contact 17 serves to protect the system against electric shock. The control conductor contacts 18 can perform various functions. In the standard described above, they serve both to detect the presence of a plug connection and to control the charging process. However, the specific pin assignment can vary depending on the plug type. The illustration shown is merely a specific embodiment of a standard plug.

[0027] In the Fig. Figure 2 shows an example of a cross-section through a multi-core electrical cable for a charging cable 13. The entire unit consisting of the charging cable together with the connector, such as the charging plug 10 shown here, can also be referred to as a charging cable. However, here the actual cable with its individual cores is referred to as the charging cable 13.

[0028] The charging cable 13 shown has a cable sheath 19 in the usual manner. The cable sheath 19 serves as an enclosure for the wires or conductors contained within. It serves to protect and mechanically hold the individual components together.

[0029] In the present case, four power conductors 16 are shown. Here, two power conductors 16 are electrically connected together in order to reduce the current load for each individual conductor.

[0030] In the middle of the charging cable 13, a protective conductor 21 runs as an additional conductor. This protective conductor 21 serves to ensure the safe dissipation of electrical energy in the event of fault currents. In this way, electric shock to persons involved and similar hazards can be avoided.

[0031] The charging cable 13 can also have several control lines or control wires 22, as shown here. These can be fully connected or only partially used.

[0032] In the present embodiment, two coolant lines 23 are shown as supply lines and two coolant lines 24 as return lines. This means that the cooling medium or coolant is pumped to the charging plug 10 via the coolant lines 23 as supply lines and returned via the coolant lines 24 as return lines. Such a uniform distribution of the coolant lines 23 and 24 in the charging cable 13 ensures good temperature distribution and, if necessary, cooling within the cable.

[0033] To ensure that the charging cable 13 has a stable and wear-resistant internal structure, filling elements 25 can be provided. These filling elements 25 serve to prevent or fill cavities in the charging cable 13. In this way, empty spaces are avoided, and in particular, handling is improved. This ensures a homogeneous and stable interior for the charging cable 13.

[0034] The external design of the charging plug 10 and the construction of the charging cable 13 are relatively universally applicable. Two preferred embodiments of the charging plug 10 according to the invention are shown below, which differ slightly in their internal construction. Specifically, the power contacts 16 have different shapes. The other components are adapted accordingly. However, the basic idea of ​​the invention is realized in both cases.

[0035] In the Fig. 3 and Fig. Figure 4 shows the first embodiment of the invention. Here, the two power contacts 16 are shown, which are connected to the corresponding power conductors 20. Weld lugs 26 are provided for connecting the power contacts 16 and the power conductors 20. The power conductors 20 are therefore welded to the weld lugs 26. In this way, it is possible to

[0036] The aim is to reduce contact resistance between the power conductors 20 and the power contacts 16 in order to allow particularly high currents to flow. However, since the heating is typically still significant in the area of ​​the plug contacts due to the contact resistance, this is usually where the greatest heat dissipation occurs.

[0037] Accordingly, suitable heat sinks 27 are provided here. A cooling fluid, such as water, can flow through the heat sinks 27 for cooling purposes. The heat sinks 27 are formed here from an upper part 28 and a lower part 29. The upper part 28 and the lower part 29 are usually permanently connected to each other, for example by welding or bonding. In this way, a leakage of cooling fluid from the heat sink 27 is prevented.

[0038] In this case, a separate heat sink 27 is provided for each of the two power contacts 16. The heat sink 27 is contacted or connected to the welding tabs 26 of the respective power contact 16. This can be done, for example, by placing them on top of each other in the fully assembled charging plug 10. However, the connection can also be additionally secured by gluing, crimping, or similar means.

[0039] Furthermore, the thermal conductivity between the heat sink 27 and the weld lugs 26 can be improved. This can be achieved, for example, by using thermal paste, thermal adhesive, a thermal pad, or similar materials. These can be placed between the heat sink 27 and the weld lugs 26.

[0040] The heat sink 27 is made of an electrically insulating material. For example, the heat sink 27 can be made of a plastic. A plastic such as PA6 or similar is suitable. Preferably, an electrically non-conductive plastic is used. This prevents electrical contact between the power contact 16 or the weld lug 26 or the power conductor 20 on the one hand and the cooling fluid flowing inside the body 27 on the other.

[0041] Accordingly, an electrically conductive liquid can also be used as the cooling fluid, particularly in the case of an insulating heat sink 27. For example, water can be used according to the invention. This is not possible in known and conventional cooling methods, since electrical conductivity would have to be prevented in these methods. Typically, the electrical contacts are directly exposed to the cooling medium in this case. Therefore, no electrical insulation is provided in the prior art.

[0042] The heat sink 27 also has hose connections 30. These hose connections 30 serve to connect the coolant lines 23 and 24 to the heat sink 27. The coolant, or cooling fluid, can thus enter the heat sink 27 through the coolant lines 23 as a supply line. This occurs here in the first end section 31 of the cooling fluid channel 32. The cooling fluid channel 32 runs through the lower part 29. Due to the meandering shape of the cooling fluid channel 32, a large area of ​​the heat sink 27 is cooled. After passing through the cooling fluid channel 32, the cooling fluid then exits from the other end section 31 into the corresponding hose connection 30. The cooling fluid can then be returned via the return line 24.

[0043] To operate the resulting cooling circuit, a suitable pump can be provided in a corresponding power supply unit or charging station. The cooling circuit can thus be designed as a closed loop. The cooling medium or coolant can therefore be circulated in a closed loop.

[0044] Accordingly, the charging station can be equipped with a cooling device for the cooling medium. Cooling by this device can be passive, for example, by dissipating heat into the environment, particularly through suitable heat sinks. It can also be active, using appropriate electrical cooling devices. For example, compressor cooling or cooling using Peltier elements can be employed. Other cooling methods are also possible.

[0045] The second embodiment in the Fig. 5 and Fig. Section 6 essentially corresponds to the statements of the Fig. 3 and Fig. 4. However, it shows different cross-sections of the power contacts 16. Here, round weld lugs 26 are shown instead of flat weld lugs 26 as in Fig. 3 and Fig. 4 are planned.

[0046] The power contacts 16 with the round weld lugs 26 are also cooled by associated heat sinks 27. In this case, the heat sinks 27 also have a round inner cross-section to match the round weld lugs 26. The heat sinks 27 surround the round weld lugs 26.

[0047] For this purpose, the lower parts 29 of the heat sinks 27 are designed with a cylindrical interior. The weld lugs 26 of the exemplary embodiment fit precisely into this cylindrical interior. By ensuring good thermal contact between the weld lugs 26 and the lower parts 29 of the heat sinks 27 in the area of ​​their circumference, good heat transfer can be achieved. Here, too, thermally conductive materials can be used to further improve contact.

[0048] In this case, the upper parts 28 of the cooling sinks 27 carry the hose connections 30. The coolant can thus enter the space between the upper part 28 and the lower part 29 through the corresponding hose connections 30. The coolant channels 32 run roughly longitudinally along the cylinder surface. This ensures good flow through the interior of the cooling sinks 27. As a result, a meandering arrangement is achieved, with the coolant flowing through all areas of the cooling sink 27.

[0049] The corresponding charging plug 10 can be connected to a corresponding charging coupling on the side of an electric vehicle. In this case, a corresponding charging process can then take place.

[0050] The method can, in particular, provide that the cooling circuit is activated when the charging plug 10 is inserted. This ensures continuous cooling. Alternatively, the cooling capacity, such as the flow rate of cooling fluid, or the switching on or off of the cooling circuit can be controlled based on measured values. For example, a temperature measurement can be provided to monitor the temperature in the charging plug 10. This allows the heat generation in the charging plug 10 to be kept within predefined limits. Reference symbol list 10 charging plugs 11 cases 12 Handle 13 charging cables 14 plug-in elements 15 plug-in elements 16 Performance Contact 17 Protective conductor contact 18 Control conductor contact 19 Cable sleeve 20 Power line 21 Protective conductor 22 Control artery 23 Cooling fluid line supply 24 Cooling fluid line return 25 filling elements 26 welding flag 27 heat sinks 28 Top 29 Lower part 30 hose connection 31 End area 32 Cooling fluid channel

Claims

[1] Charging plug for electrically charging an electric vehicle, in particular for transmitting high power, with at least one power contact (16), preferably two power contacts (16) for conducting electrical energy, characterized by , that a cooling system with a cooling fluid is provided for cooling the at least one power contact (16). [2] Charging plug according to claim 1, characterized by that the cooling system has at least one heat sink (27), preferably the at least one heat sink (27) is fluid-permeable or fluid-permeable, and further preferably its housing. [3] Charging plug according to claim 1 or 2, characterized by, that the at least one heat sink (27) is assigned to the at least one power contact (16), preferably is in contact with it, wherein preferably each of the several power contacts (16) is assigned one of the heat sinks (27), further preferably each of the power contacts (16) has a separate heat sink (27). [4] Charging plug according to any of the preceding claims, characterized by , that the at least one heat sink (27) is thermally contacted and / or connected to the at least one power contact (16) or one of the power contacts (16), wherein the contact and / or the connection is preferably thermally conductive. [5] Charging plug according to any one of the preceding claims, characterized by, that the cooling fluid is electrically insulated from the at least one power contact (16), in particular is conducted in an electrically insulated manner, wherein preferably an electrical insulation is provided, preferably as an insulating layer, in particular between the cooling fluid and the power contact (16). [6] Charging plug according to any one of the preceding claims, characterized by , that the at least one heat sink (27), in particular its housing, is electrically insulating, wherein preferably the at least one heat sink (27), in particular its housing, is made of an electrically insulating material, in particular a plastic. [7] Charging plug according to any of the preceding claims, characterized by , that a liquid is or may be provided as the cooling fluid, which is or may be electrically conductive, preferably water being provided as the cooling fluid. [8] Charging plug according to any of the preceding claims, characterized by , that the at least one heat sink (27) has at least one cooling fluid channel (32) inside for conveying the cooling fluid, preferably a meandering cooling fluid channel (32), wherein the at least one cooling fluid channel (32) extends in particular preferably over almost the entire surface of the at least one heat sink (27). [9] Charging plug according to any one of the preceding claims, characterized by , that at least two connections for cooling fluid lines (23, 24), in particular hose lines, are provided, wherein preferably at least one of the cooling fluid lines (23) is provided as a cooling fluid supply line or flow and at least one of the cooling fluid lines (24) is provided as a cooling fluid discharge or return and / or wherein the connections are connected to the end regions (31) of the respective cooling channels (32). [10] Charging plug according to any one of the preceding claims, characterized by, that the at least one heat sink (27) is composed of several parts, in particular at least one upper part (28) and at least one lower part (29), wherein the parts are preferably permanently connected to each other, preferably glued or welded together. [11] Charging cable or charging line for electrically charging an electric vehicle, in particular for transmitting high power, comprising a cable sheath (19), with at least two electrical conductors running through the cable sheath (19), preferably power conductors (20) for transmitting electrical energy, and with a charging plug (10), in particular according to one of the preceding claims, with at least two power contacts (16) connected to the power conductors (20) for transmitting electrical energy to the electric vehicle, characterized by , that a cooling system with a cooling fluid is provided for cooling the at least two power contacts (16) and / or the power conductors (20). [12] Charging cable according to claim 11, characterized by , that at least two cooling fluid lines (23, 24) are provided in the cable sheath (19), preferably for supplying and / or removing cooling fluid for cooling the power contacts (16), wherein in particular a cooling circuit is provided, and / or that at least one control wire (22) is provided in the cable sheath (19), preferably for exchanging control signals and / or for data transmission. [13] Charging system with a charging plug, in particular according to one of claims 1 to 10, with a charging cable (13), in particular according to claim 11 or 12, for connecting the charging plug to a power supply unit, in particular a charging station, and with a charging coupling corresponding to the charging plug (10) on the electric vehicle to be charged, in order to transfer electrical energy between the power supply unit and the electric vehicle, characterized by, that a cooling system with fluid cooling is provided for cooling at least one power contact (16) of the charging plug (10). [14] Charging system according to claim 13, characterized by , that cooling fluid lines (23, 24) run through the charging cable (13), in particular parallel to the power lines, wherein preferably at least a cooling effect also occurs on the cable (13) or on the electrical lines located therein, and / or that the power supply unit, in particular charging station, has a unit with a cooling circuit for the cooling fluid, preferably with a pump device, wherein the cooling circuit runs through the charging cable (13) to the charging plug (10). [15] Method for electrically charging an electric vehicle, in particular by transmitting high power, with a charging plug (10) in particular according to one of claims 1 to 10 with at least two power contacts (16) for conducting electrical energy, characterized by, that at least two power contacts (16) are cooled with a cooling fluid. [16] Method according to claim 15, characterized by , that the power contacts (16) are cooled by means of fluid-flowed cooling elements (27), and / or that a cooling circuit for the cooling fluid is routed through the charging cable (13), in particular through coolant lines (23, 24), and / or that the cooling circuit is operated during the charging process, and / or that the cooling circuit is operated depending on the measured value, in particular temperature-controlled.

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