System for electric vehicle and hybrid vehicle

Abstract

The invention relates to a system having a charging plug (1) and a control unit (8) for electric and hybrid vehicles (18), the charging plug (1) having a housing (7), a charging contact (2) arranged in the housing (7) for contacting a corresponding charging contact (3) of a corresponding charging plug (4), and a cooling element (5) arranged in the housing (7), and a cooling element (5) which is coupled to at least one of the charging contacts (2) in such a way that the charging contacts (2) can be cooled by means of the cooling element (5), the cooling element (5) being connected to a control unit (8) in such a way that a cooling function of the cooling element (5) can be controlled by means of the control unit (8), the control unit (8) being arranged to activate the cooling function of the cooling element at a time outside the charging process. In this way, charging of the battery of the electric or hybrid vehicle (18) with a strong current over a longer period of time is achieved.

Description

Technical Field

[0001] The present invention relates to a system having a charging plug for electric vehicles and hybrid vehicles, wherein the charging plug has a housing, charging contacts arranged in the housing, and a cooling element, wherein the charging contacts are used to contact corresponding charging contacts of the corresponding charging plug, and the cooling element is coupled to at least one of the charging contacts so that the charging contacts can be cooled by means of the cooling element. Background Art

[0002] Electric vehicles and hybrid vehicles have a rechargeable energy storage device, usually a high-voltage battery, which supplies energy to the power motor during driving. The storage capacity of the high-voltage battery is limited, so the high-voltage battery must be recharged at a charging station regularly. The battery is charged via a charging cable arranged between the charging station and the vehicle, wherein the charging cable is provided with a charging plug that can be inserted into a charging socket arranged on the charging station on one side, and a charging coupling that can be connected to an internal charging plug installed on the electric vehicle and hybrid vehicle on the other side, for example, according to the European standard IEC 62196 Type 2. Here, the charging socket, charging plug, charging coupling and internal charging plug are all included under the term "charging plug connector". The charging socket and the charging coupling have contact sleeves as charging contacts, while the charging plug and the internal charging plug that can be installed on the electric vehicle and hybrid vehicle have contact pins that can be inserted into the contact sleeves as charging contacts.

[0003] For example, as described in EP 3 043 421 A1, due to the charging current flowing through the charging connector, the charging connector generates heat due to ohmic current heat loss. However, the heat generation of the charging connector is limited in terms of the limit temperature rise. Therefore, for example, according to the standard IEC 62196-3, the limit temperature rise is limited to 50K. For most standardized connector geometries, this in turn leads to a maximum charging current, which is usually not greater than 200A in continuous load operation. However, in the case of intermittent charging of batteries of electric vehicles or hybrid vehicles, it is necessary to use a larger charging current within a limited period of time in order to charge the battery in the desired short time. This may lead to temporary heating of the charging connector that exceeds the limit temperature rise. The wire cross-section of the electrical connector cannot be increased arbitrarily, because the connector geometry is standardized. In addition, as little conductive material as possible should be used for the electrical connector, which is usually copper.

[0004] In this context, according to EP 3 043 421 A1, the object to be achieved is to provide an electrical coupling body which enables an increased charging current with limited heat generation and thus has an increased short-term current carrying capacity. This object is achieved in that an electrical coupling body for a charging plug or charging socket is provided, wherein the electrical coupling body has a first connection area for electrical connection to an electrical energy receiver and a second connection area for electrical connection to an electrical power source, wherein the electrical coupling body is designed such that it has a cooling fluid channel formed in the electrical coupling body, wherein the cooling fluid channel of the electrical coupling body is fluidically connected to a cooling fluid source arranged at the charging station.

[0005] In other respects, it is also known in the prior art that the charging plug for electric vehicles and hybrid vehicles is cooled by the charging station. DE 10 2015 119 338 A1 describes two connection locations for coolant lines arranged on the contact sleeve element of the charging plug. The coolant is guided cyclically around the contact sleeve element by a spiral plug-in element. The two connection locations serve as the inlet and outlet of the coolant that is transported from the charging station to the charging plug. EP 3 433 902 B1 also describes a plug connector with cooled contact elements. Here, the charging station is also configured to guide the coolant through the coolant line to the contact element of the charging coupling connected to the charging cable. The following fluid is provided as a coolant, which is guided into the hollow contact element perpendicular to the contact element and flows back into the contact element. Finally, DE 102016 105 361 B4 also describes a plug connector with cooled contact elements, wherein here, on the charging station side, a contact element is also provided to guide a coolant via a coolant line to a charging socket connected to a charging cable. In this case, a guide element is arranged on the contact element, which guide element ensures that the coolant in the form of compressed air flows around the contact element. Summary of the invention

[0006] Based on this, the object of the present invention is to enable charging of a battery of an electric vehicle or a hybrid vehicle with a high current over a longer period of time.

[0007] This object is achieved by the subject matter of the independent claims. Preferred developments of the invention are described in the dependent claims.

[0008] Therefore, according to the present invention, a system having a charging plug and a control unit for electric vehicles and hybrid vehicles is proposed, wherein the charging plug has a housing, charging contacts arranged in the housing, and a cooling element, the charging contacts are used to contact corresponding charging contacts of the corresponding charging plug, the cooling element is coupled to at least one of the charging contacts so that the charging contact can be cooled by the cooling element, the cooling element is connected to the control unit so that the cooling function of the cooling element can be controlled by the control unit, and the control unit is configured to activate the cooling function of the cooling element at times other than the charging process.

[0009] When a corresponding charging plug is mentioned here, on the one hand, it refers to a charging plug having the same plug-in surface as the charging plug according to the present invention, but wherein, if one plug-in surface has a contact sleeve, the other plug-in surface has a contact pin, or vice versa. Therefore, the set formed by the charging plug according to the present invention and the corresponding charging plug can be plugged together. On the other hand, the "corresponding charging plug" mentioned in this article also includes the situation where the plug-in surface only partially corresponds in the above sense, that is, the corresponding charging plug, for example, does not have all the contacts provided in the charging plug according to the present invention, but the existing contacts of the corresponding charging plug correspond to the charging plug according to the present invention in terms of the plug-in surface, so that the charging plug according to the present invention and the corresponding charging plug can also be plugged together in this case.

[0010] An example of this is a charging coupling for direct current charging and connected to a charging cable that complies with European standard IEC 62196 Type 2. This charging coupling can be inserted into a built-in charging plug installed on the body of an electric vehicle or hybrid vehicle and is suitable for both alternating current charging and direct current charging, wherein in the direct current charging coupling, only communication contacts and protective contacts are present on the alternating current plug surface, but no contacts for the phase line and neutral line required for alternating current charging are present.

[0011] Here, a cooling element is understood to be an element that causes, in a system according to the invention comprising a charging plug and a control unit, active cooling of the charging contacts is caused by the cooling element. By active cooling, the charging contacts of the charging plug according to the invention are cooled outside the charging process, so that the temperature of the charging contacts is lower than the ambient temperature at the beginning of the charging process. As a result, the maximum permissible temperature limit is reached later when charging with a higher charging current. Compared to a charging process when the charging contacts are at ambient temperature, the system according to the invention enables a charging process of longer duration at a higher charging current.

[0012] Different methods can be used to detect whether a charging process is in progress. The control unit can be connected to the communication contacts of the charging connector, for example, so that the charging process can be recorded via the communication contacts. Likewise, the control unit can be connected to the charging contacts to detect the charging process. The control unit is designed to cool the charging contacts only outside the charging process. The control unit can be arranged in the charging connector to provide a more compact configuration of the system according to the invention. However, the control unit can also be arranged outside the charging connector in particular.

[0013] Therefore, an important aspect of the present invention is that a charging process with a higher charging current and a longer duration is achieved by pre-cooling the charging contacts, so that more electrical energy can be transmitted, especially in the case of intermittent charging. The present invention is also used to bridge the period at the beginning of the charging process, during which the cooling device of the charging station must be started and the charging contacts of the charging connector according to the present invention cannot yet be effectively used. To this end, the cooling element is thermally coupled to the charging contacts so that the charging contacts can be efficiently cooled. Particularly preferably, the cooling element directly contacts the charging contacts for this purpose, that is, contacts the charging contacts without electrical insulation. The cooling element can also be provided with a heat pipe, which can achieve thermal connection with the charging contacts. Here, a solid material tube (Vollmaterialrohr) with high thermal conductivity is preferably used as a heat pipe. Similarly, the cooling element can be coupled to the charging contacts by means of a thermally conductive paste.

[0014] According to a preferred refinement of the invention, the time outside the charging process is the time just before the currently planned charging process. The cooling power of the cooling element is known, so that the lowest achievable temperature of the charging contacts relative to the ambient temperature is also known. Here, the lowest achievable temperature is the lowest possible temperature that can be achieved taking into account the ambient temperature and the cooling power. Therefore, for more efficient cooling, it can be provided that the cooling starts at a certain time before the planned charging process, so that the charging contacts have the lowest achievable temperature when the charging process starts.

[0015] In principle, the cooling element can be formed in different ways. However, according to a preferred development of the invention, it is provided that the cooling element is a Peltier element. A Peltier element is an electrothermal converter which generates a temperature difference when an electric current flows due to the Peltier effect. The Peltier element can be used for cooling and heating. In this case, the Peltier element is used for cooling. The Peltier element is therefore a cooling element which does not require a flow connection to the charging contact.

[0016] The temperature of the charging contacts and the corresponding charging contacts are equalized by the charging contacts connected in the coupled state, so that the charging contacts and the corresponding charging contacts have a temperature below the ambient temperature as a whole due to precooling at the beginning of the charging process. It is particularly useful if the corresponding charging plug is equipped with an active cooling system, as described at the beginning with reference to the prior art. The system provided according to the invention can keep the temperature of the charging contacts of the charging plug and the temperature of the corresponding charging contacts of the corresponding charging plug below a limit temperature rise, that is, until the active cooling system provided by the charging station is used.

[0017] According to a preferred improvement of the present invention, it is provided that a Peltier element having a hot side and a cold side is thermally connected to the charging contact with the cold side, and the hot side is coupled to the environment, so that heat transfer / heat dissipation from the charging contact to the environment can be achieved. This prevents the charging connector from being heated by heat transfer from the hot side, thereby inhibiting the cooling of the charging contact. For this purpose, it can be provided that the Peltier element extends from the housing of the charging connector and causes cooling by convection. However, fluid-based cooling can also be achieved at the hot side of the Peltier element. It is also conceivable that the hot side is thermally connected to the body of the vehicle via a heat pipe, so that the heat generated on the hot side can be dissipated through the body.

[0018] In this regard, it is also preferred that the hot side is connected to an additional convection element so that the heat can be dissipated to the environment via the convection element by convection. For this purpose, the convection element can be thermally coupled to the hot side of the Peltier element via a heat-conducting paste. In this case, the convection element preferably protrudes from the housing of the charging connector in order to enable efficient heat transfer to the environment by convection.

[0019] It is also preferred that the system including the charging plug and the control unit is provided with a connection area in the housing, in which the charging contact is electrically conductively connected to the wire leading out of the charging plug, wherein the charging contact has a notch in the connection area, and the cooling element is arranged in the notch. A large contact area between the charging contact and the cooling element can be ensured by the notch.

[0020] In this case, the connection region of the charging plug is referred to as that region of the charging plug in which the charging contacts are electrically conductively connected to electrical lines leading out of the charging plug.

[0021] In principle, a system with a charging plug and a control unit can be provided with only one cooling element. However, according to a preferred refinement of the invention, it is provided that the system according to the invention has a further cooling element, wherein the further cooling element is connected to the control unit and to other of the charging contacts, so that the other charging contacts can be cooled by the cooling element. In particular, according to a preferred refinement of the invention, each charging contact is provided with its own cooling element.

[0022] The invention also relates to the use of the above system in an electric vehicle or a hybrid vehicle. In this case, the charging connector can be designed according to European standard IEC 62196 type 2.

[0023] The invention further relates to a method for operating a charging plug for an electric vehicle or a hybrid vehicle, wherein the charging plug has a charging contact and a cooling element, the charging contact being used to contact a corresponding charging contact of a corresponding charging plug, the cooling element being coupled to at least one of the charging contacts so that the charging contact can be cooled by the cooling element, the method comprising the following method steps:

[0024] S1) detects whether the charging process is currently in progress.

[0025] S2) The cooling element is switched on only when it is detected that no charging process is taking place.

[0026] It is important here that cooling can only be performed outside of a charging process. For this purpose, it is detected whether a charging process is currently being performed. However, this does not mean that cooling is always performed when a charging process is not being performed. Cooling is started at a point in time between two consecutive charging processes, preferably so that the lowest achievable temperature is achieved when a charging process is started. In this case, cooling is preferably performed so that the lowest achievable temperature is achieved immediately before the charging process is started.

[0027] According to a preferred improvement of the present invention, the method further comprises the following method steps:

[0028] S3) detects whether the charging process is currently in progress or about to occur, that is,

[0029] S4) When it is detected that a charging process is currently in progress or is about to occur, disconnecting the cooling element.

[0030] Furthermore, preferably, the method additionally comprises the following steps:

[0031] S1a) detecting the value of a charging-specific parameter,

[0032] S2a) determining a duration before starting the charging process using charging-specific parameters,

[0033] S2b) Switching on the cooling element as soon as the determined duration falls below a predetermined duration threshold.

[0034] Therefore, here a charging-specific parameter is detected, by which a duration before the start of the charging process can be determined. As soon as the predetermined duration is below a predetermined duration threshold, the cooling element is switched on, so that the charging contacts can have the lowest achievable temperature just before the start of the charging process. The term "duration" therefore refers to a period of time before the start of the charging process. According to a preferred refinement of the invention, the corresponding value of the charging-specific parameter is continuously detected in step S1a. It can thus be checked continuously whether the duration is below a predetermined duration threshold, so that the cooling element can be activated at the right moment.

[0035] In principle, various parameters can be set as charging-specific parameters. However, according to a preferred development of the invention, it is provided that the charging-specific parameter is the battery charge value, i.e. a value indicating the remaining battery charge. This battery charge value is directly related to the remaining drivable distance, which in turn is related to the duration threshold. It can be determined when the charging process must be started based on the battery charge value. In the sense of the invention, a distance can correspond to a spatial distance and a temporal distance.

[0036] According to another preferred development of the invention, the charging-specific parameter is the vehicle position. The distance to a charging station to be approached can be determined based on the vehicle position, for example, so that cooling of the charging contacts begins when a duration threshold is fallen below.

[0037] According to another preferred development of the invention, the charging-specific parameter is the time of day. Regular driving makes it possible to start cooling the charging contacts depending on the time of day. If the charging process is expected to start at a certain time of day, the charging contacts can be cooled accordingly in advance.

[0038] Finally, according to a preferred development of the invention, it is provided that the charging-specific parameter is a value from a vehicle navigation system of the electric vehicle or hybrid vehicle, which indicates that the electric vehicle or hybrid vehicle is approaching the charging station. In this context, it is provided in particular that the value from the vehicle navigation system of the electric vehicle or hybrid vehicle indicates an expected arrival time at the charging station and / or a duration for the electric vehicle or hybrid vehicle to reach the charging station. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention will be further described in detail below through preferred embodiments with reference to the accompanying drawings.

[0040] in:

[0041] FIG. 1 schematically shows a system having a charging plug and a control unit according to a preferred embodiment of the present invention.

[0042] FIG. 2 shows a plug connector corresponding to the plug connector of FIG. 1 ,

[0043] FIG. 3 a shows the charging connector of FIG. 1 in a side view,

[0044] FIG. 3 b schematically shows a charging contact with a cooling element of the charging plug connector of FIG. 3 a ,

[0045] FIG. 4 shows in a schematic diagram the cooling element with the convection element shown in FIG. 3 b ,

[0046] FIG. 5 schematically shows a charging connector according to a preferred embodiment of the present invention installed in a body of an electric vehicle or a hybrid vehicle, and

[0047] FIG. 6 shows a flow chart of a method according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0048] FIG1 schematically shows a system with a charging plug 1 and a control unit 8 according to a preferred embodiment of the invention. This is a built-in charging plug, which is intended to be installed in a vehicle body 17 of an electric vehicle or hybrid vehicle 18, as schematically shown in FIG5. The charging plug 1 is essentially and from its plug face a built-in charging plug according to European standard IEC 62196 type 2. In addition to the AC current charging contacts, which are not provided with additional reference numerals, the charging plug 1 has a protective contact 15, a communication contact 16 and two charging contacts 2 for DC current charging.

[0049] The charging plug 1 consists of a front housing part 27 and a rear housing part 28. The two housing parts together thus form the housing 7 of the charging plug 1. The front housing part 27 is connected to the rear housing part 28 by laser welding. The front housing part 27 is a housing part which, when installed in the vehicle body 17, faces outward and is arranged to receive a corresponding charging plug 4.

[0050] Such a corresponding charging plug connector 4 can be seen in the stereoscopic view of FIG. 2 . This is a charging coupling for direct current charging, which corresponds in essence and from its plug surface to the European standard IEC 62196 Type 2. For direct current charging, two corresponding charging contacts 3 are provided in the housing 13 , which interact with the charging contacts 2 of the charging plug connector 1 during charging. Specifically, the charging contacts 2 of the charging plug connector 1 are configured as contact pins, while the corresponding charging contacts 3 of the corresponding charging plug connector 4 are configured as contact sleeves, into which the contact pins can be inserted. In addition, the corresponding charging plug connector 4 has two communication contacts 16 and a protective contact 15 .

[0051] As can be seen in particular from FIG. 3 a , the charging plug 1 has a plug-in region in the front housing part 27 and a connection region in the rear housing part 28 . The plug-in region is defined as the region in which the charging plug 1 overlaps with the corresponding charging plug 4 in the plug-in direction when plugged into the corresponding charging plug 4 and the charging contacts 2 , 3 of the two plugs 1 , 4 are in conductive contact with each other. The connection region is defined as the region in which the charging contacts 2 of the charging plug are conductively connected to the electrical lines 14 leading from the charging plug 1 to the battery (not shown in further detail) .

[0052] In this case, it is important in the preferred embodiment of the invention described here that the two cooling elements 5 are Peltier elements 6 in the present embodiment, which are arranged in recesses 12 of the charging contact 2. The cold side 10 of the Peltier element 6 is arranged in the recess 12 and contacts the recess. The hot side 9 is on the side opposite the cold side 10 and is thermally coupled to the vehicle body 17 via a heat pipe (not shown). The recess 12 is arranged in the connection area of ​​the charging plug 1.

[0053] FIG. 3 b shows a perspective view of charging contacts 2 of a charging plug connector 1 with recesses 12 . Each charging contact 2 has a recess 12 in which a Peltier element 6 is arranged. The Peltier element 6 is connected to a control unit 8 and is controlled by the control unit, i.e., in particular, activated or deactivated. For this purpose, the control unit 8 is arranged on the vehicle body 17 and is also connected to the communication contacts 16 of the charging plug connector 1 .

[0054] However, it should be noted in this case that the arrangement of the Peltier elements 6 in the recesses 12 of the heat conducting element shown in FIG. 3 b is nonetheless very advantageous for heat transfer from the charging contact 2 . However, other arrangements of the Peltier elements 6 are also conceivable.

[0055] 4 that, instead of transferring heat to the Peltier element 6 via a heat pipe, a convection element 11 can be arranged in direct contact with the hot side 10 of the Peltier element 6. To this end, the convection element 11 has a particularly high surface to volume ratio, thereby providing a particularly large surface area for heat transfer for convection cooling.

[0056] It has already been mentioned above that the charging connector 1 in the form of a built-in plug is used on the vehicle body 17 of an electric vehicle or hybrid vehicle 18. In this regard, reference is made here to FIG. 5 , which schematically shows the charging connector 1 installed in the vehicle body 17 of an electric vehicle or hybrid vehicle 18.

[0057] FIG6 schematically shows a flow chart of a method flow for operating a charging plug connector 1 for an electric vehicle and a hybrid vehicle 18 according to a preferred embodiment of the present invention. A first step S1 comprises: detecting whether a charging process is currently in progress. Then, in step S1a, the corresponding values ​​of charging-specific parameters are continuously detected. Here, the charging-specific parameter is the state of charge of the battery of the electric vehicle or hybrid vehicle 18. In another step S2a, a duration before the start of the charging process is determined by charging-specific parameters. Specifically, the expected remaining driving range in the form of a duration is continuously calculated according to the state of charge of the battery. Once the duration is below a predetermined duration threshold, the cooling element 5 is turned on by the control unit 8 in step S2b. In another step S3, it is re-detected whether a charging process is in progress or about to start. When it is detected in step S3 that a charging process is in progress or about to start, the cooling element 5 is turned off in step S4.

[0058] List of reference numerals:

[0059] 1 Charging connector

[0060] 2 Charging contacts

[0061] 3 Corresponding charging contacts

[0062] 4 Corresponding charging connector

[0063] 5 Cooling element

[0064] 6 Peltier elements

[0065] 7 Housing

[0066] 8 Control unit

[0067] 9 Hot side

[0068] 10 Cold side

[0069] 11 Convection element

[0070] 12 Gap

[0071] 13 Housing

[0072] 14 Electrical wires

[0073] 15 Protective contact parts

[0074] 16 Communications Contact Department

[0075] 17 Vehicle body

[0076] 18 Electric or hybrid vehicles

[0077] 19 Cooling element

[0078] 27 Front housing part

[0079] 28 Rear housing part.

Claims

1. A system having a charging plug (1) and a control unit (8) for an electric vehicle or a hybrid vehicle (18), wherein: The charging plug (1) comprises a housing (7), a charging contact (2) arranged in the housing (7), and a cooling element (5), wherein the charging contact is used to contact a corresponding charging contact (3) of a corresponding charging plug (4), the cooling element is coupled to at least one of the charging contacts (2), so that the charging contact (2) can be cooled by the cooling element (5), the cooling element (5) is connected to a control unit (8), so that the cooling function of the cooling element (5) can be controlled by the control unit (8), and the control unit (8) is configured to activate the cooling function of the cooling element at a time other than a charging process.

2. The system according to claim 1, characterized in that The time outside the charging process is the time before the currently planned charging process.

3. The system according to claim 1 or 2, characterized in that: The cooling element (5) is a Peltier element (6).

4. The system according to claim 3, characterized in that A Peltier element (6) having a hot side (9) and a cold side (10) is connected thermally to a charging contact (2) with the cold side (9) and is coupled to the environment with the hot side (9) so that heat transfer from the charging contact (2) to the environment is possible.

5. The system according to claim 3 or 4, characterized in that: The hot side (10) is connected to a convection element (11) so that heat can be transferred to the environment by convection via the convection element (11).

6. A system according to any one of the preceding claims, characterised in that The cooling element (5) is in direct contact with the charging contact (2).

7. A system according to any one of the preceding claims, characterised in that A connection area is provided in the housing (7), in which the charging contact (2) is electrically conductively connected to an electrical line (14) leading from the charging plug (1), wherein the charging contact (2) has a recess (12) in the connection area, in which the cooling element (5) is arranged.

8. A method for operating a charging plug connector (1) for an electric vehicle or a hybrid vehicle (18), wherein: A charging plug (1) has a charging contact (2) and a cooling element (5), wherein the charging contact is used to contact a corresponding charging contact (3) of a corresponding charging plug (4), and the cooling element is coupled to at least one of the charging contacts (2) so that the charging contact (2) can be cooled by the cooling element (5). The method comprises the following method steps: S1) detects whether the charging process is currently in progress. S2) The cooling element (5) is switched on only when it is detected that no charging process is taking place.

9. The method according to claim 8, further comprising the following steps: S3) detects whether the charging process is currently in progress or about to occur. S4) When it is detected that a charging process is currently being carried out or is about to take place, the cooling element (5) is disconnected.

10. The method according to claim 8 or 9, further comprising the steps of: S1a) detecting the value of a charging-specific parameter, S2a) determining a duration before starting the charging process using charging-specific parameters, S2b) As soon as the determined duration falls below a predetermined duration threshold, the cooling element (5) is switched on.

11. The method according to any one of claims 8 to 10, characterized in that In step S1 a , the corresponding values ​​of the charging-specific parameters are continuously detected.

12. Use of a system according to any one of claims 1 to 7 in an electric vehicle or a hybrid vehicle (18).

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