System for electric and hybrid vehicles

Abstract

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

Description

[0001] System for electric and hybrid vehicles

[0002] Description:

[0003] The invention relates to a system with a charging connector for electric and hybrid vehicles, wherein the charging connector has a housing, charging contacts arranged in the housing for contacting corresponding charging contacts of a corresponding charging connector, and a cooling element which is coupled to at least one of the charging contacts in such a way that the charging contact can be cooled by means of the cooling element.

[0004] Electric and hybrid vehicles have a rechargeable energy storage device, usually a high-voltage battery, which supplies energy to an electric drive motor during operation. The storage capacity of these high-voltage batteries is limited, so they must be recharged regularly at a charging station. The battery is charged via a charging cable provided between the charging station and the vehicle. The charging cable, for example, in accordance with the European standard IEC 62196 Type 2, is equipped with a charging plug on one end that can be plugged into a charging socket provided on the charging station, and a charging coupling on the other end that can be connected to a charging plug installed in the electric or hybrid vehicle. For the purposes of this article, charging sockets, charging plugs, charging couplings and charging plugs are all referred to as “charging connectors”.Charging sockets and charging couplings have contact sleeves as charging contacts, and charging plugs as well as charging plugs that can be installed in electric and hybrid vehicles have contact pins as charging contacts that can be inserted into the contact sleeves.

[0005] As explained, for example, in EP 3 043 421 A1, a charging current flowing through the charging connector causes it to heat up due to ohmic current heat losses. However, the heating of the charging connector is limited to a threshold temperature increase. For example, according to the IEC 62196-3 standard, the threshold temperature increase is limited to 50 K. This in turn leads to a maximum charging current for largely standardized connector geometries that generally cannot exceed 200 A in continuous load operation. However, with intermittent charging of the battery of an electric or hybrid vehicle, higher charging currents over limited periods are necessary in order to charge the battery in the desired short time. This can lead to temporary heating of the charging connectors that exceeds the threshold temperature increase.The cable cross-section of the electrical connector bodies cannot be increased arbitrarily, since the connector geometries are standardized and, in addition, the smallest possible amount of conductive material, usually copper, should be used for the electrical connector bodies.

[0006] In this respect, according to EP 3 043 421 A1, the object is to be achieved by providing an electrical connection body that enables increased charging currents with limited heating and therefore has an increased short-term current carrying capacity. This object is to be achieved by providing an electrical connection body for a charging plug or a charging socket, wherein the electrical connection body has a first connection area for galvanic connection with an electrical energy receiver and a second connection area for galvanic connection with a

[0007] electrical energy source, wherein the electrical connection body is designed such that it has a cooling fluid channel formed in the electrical connection body, wherein the cooling fluid channel of the electrical connection body is fluidly connected to a cooling fluid source which is arranged in a charging station.

[0008] Cooling of a charging connector for electric and hybrid vehicles, which originates from the side of the charging station, is also well known from the prior art. DE 10 2015 119 338 A1 describes two connection points for coolant lines arranged on a contact sleeve element of a charging plug. By means of a spiral-shaped plug-in element, coolant is guided in a circle around the contact sleeve element. The two connection points serve as inlet and outlet for the coolant, which is guided from the charging station to the charging plug. EP 3 433 902 B1 also describes a connector part with cooled contact elements. Here, too, the supply of coolant via coolant lines to the contact elements of the charging coupling connected to the charging cable is provided on the charging station side.A fluid is provided as the coolant, which is directed perpendicular to the contact element into the hollowed-out contact element and flows back within the contact element. Finally, German Patent Application 10 2016 105 361 B4 also describes a connector part with a cooled contact element, whereby, on the charging station side, a coolant is also provided via coolant lines to the contact elements of a charging socket connected to the charging cable. Guide elements are arranged on the contact elements, which ensure that the coolant flows around the contact elements. the coolant should be provided in the form of compressed air.

[0009] Based on this, the object of the present invention is to enable charging of a battery of an electric or hybrid vehicle with high currents over a longer period of time.

[0010] This object is achieved by the subject matter of the independent claims. Preferred developments of the invention are described in the subclaims.

[0011] According to the invention, a system is thus provided with a charging connector for electric and hybrid vehicles and a control unit, wherein the charging connector has a housing, charging contacts arranged in the housing for contacting corresponding charging contacts of a corresponding charging connector and a cooling element which is coupled to at least one of the charging contacts in such a way that the charging contact can be cooled by means of 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 means of the control unit, and the control unit is configured to activate the cooling function of the cooling element at a time outside of a charging process.

[0012] When we speak of a corresponding charging connector in the present case, we mean, on the one hand, a charging connector which has the same plug-in face as the charging connector according to the invention, but one plug-in face has contact pins, while the other

[0013] The plug face has contact sleeves, and vice versa. The set comprising the charging plug connector according to the invention and the corresponding charging plug connector can therefore be plugged together. On the other hand, the term "corresponding charging plug connector" is also used here if the plug faces in the aforementioned sense only partially correspond, i.e. the corresponding charging plug connector, for example, does not have all the contacts that are present in the charging plug connector according to the invention, but the existing contacts of the corresponding charging plug connector correspond to the charging plug connector according to the invention in terms of the plug face, so that the charging plug connector according to the invention and the corresponding charging plug connector can also be plugged together in this case.

[0014] One such case is a charging coupling connected to a charging cable for direct current charging in accordance with the European standard IEC 62196 Type 2. Such a charging coupling can be plugged into a charging plug installed in the body of an electric or hybrid vehicle and suitable for alternating current charging as well as direct current charging, whereby the AC plug face of the DC charging coupling only has the communication contacts and the protective contact, but no contacts for the outer conductor and a center conductor for alternating current charging.

[0015] In the present case, a cooling element is understood to be an element which results in active cooling of the charging contacts in the system according to the invention comprising a charging connector and a control unit by the

[0016] Cooling element is used. Through active cooling, the charging contacts of the charging connector according to the invention are cooled at a time outside of the charging process, so that the charging contacts have a temperature lower than the ambient temperature when the charging process begins. As a result, the maximum permissible limit temperature is reached later when charging with higher charging currents. Compared to a charging process with charging contacts at ambient temperature, the system according to the invention enables a longer charging process with higher charging currents.

[0017] Detecting whether or not a charging process is taking place can be accomplished in various ways. For example, the control unit can be connected to communication contacts of the charging connector, so that a charging process can be registered via the communication contacts. Likewise, the control unit can be connected to the charging contacts to detect a charging process. The control unit is designed to cool the charging contacts exclusively at a time when a charging process is not in progress. It is possible for the control unit to be arranged in the charging connector to provide a more compact design for the system according to the invention. In particular, however, the control unit can also be arranged outside the charging connector.

[0018] It is therefore a key aspect of the invention to enable a longer charging process with higher charging currents by means of pre-cooling of the charging contacts, so that in particular in the case of intermittent

[0019] charging, a larger amount of electrical energy can be transferred. The invention also serves to bridge the period at the beginning of a charging process in which cooling from the charging station has yet to start up and is therefore not yet effectively available for the charging contacts of the charging connector according to the invention. For this purpose, the cooling element is thermally coupled to the charging contacts so that the charging contacts can be cooled efficiently. Most preferably, the cooling element contacts the charging contact directly for this purpose, i.e. without electrical insulation. The cooling element can also be provided with heat pipes for this purpose, which enable a thermal connection with the charging contacts. Solid material pipes which have high thermal conductivity are preferably used as heat pipes. Likewise, the cooling element can be coupled to the charging contacts by means of a thermally conductive paste.

[0020] According to a preferred development of the invention, the time outside of a charging process is a time immediately before a currently planned charging process. The cooling capacity of the cooling element is known, so that the minimum achievable temperature of the charging contacts in relation to the ambient temperature is also known. The minimum achievable temperature is the lowest possible temperature that can be achieved taking into account the ambient temperature and the cooling capacity. For more efficient cooling, it can therefore be provided that the cooling begins at a specific time before a planned charging process, so that the charging contacts are at the minimum achievable temperature when the charging process begins.

[0021]

[0022] In principle, the cooling element can be formed in different ways. However, according to a preferred embodiment of the invention, the cooling element is a Peltier element. A Peltier element is an electrothermal converter that generates a temperature difference based on the Peltier effect when current flows through it. Peltier elements can be used for both cooling and heating. In this case, they are used for cooling. Peltier elements are therefore cooling elements that do not require any fluid connections to the charging contacts.

[0023] The charging contacts, connected in the coupled state, equalize the temperature of the charging contacts and the corresponding charging contacts, so that, due to pre-cooling, their overall temperature is lower than the ambient temperature at the start of the charging process. This is particularly useful if the corresponding charging connector is equipped with an active cooling system, as described above with reference to the prior art. The system provided according to the invention allows the temperature of the charging contacts of the charging connector and the temperature of the corresponding charging contacts of the corresponding charging connector to be kept below the limit temperature increase until the active cooling system provided by the charging station is activated.

[0024] According to a preferred development of the invention, it is provided that the Peltier element having a hot side and a cold side, with which

[0025] The cold side is thermally conductively connected to the charging contact and the hot side is coupled to the environment in such a way that heat can be dissipated from the charging contact to the environment. This prevents heat dissipation from the hot side from heating up the charging connector and thus inhibiting cooling of the charging contacts. For this purpose, the Peltier element can protrude from the housing of the charging connector and cooling is achieved via convection. However, fluid-based cooling can also be implemented on the hot side of the Peltier element. It is also conceivable for the hot side to be thermally conductively connected to the body of a vehicle via heat pipes, so that the heat generated on the hot side can be dissipated via the body.

[0026] In this context, it is also preferable that the hot side is connected to an additional convection element in such a way that heat is 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 thermally conductive paste. The convection element preferably protrudes from the housing of the charging connector to enable effective heat dissipation to the environment by convection.

[0027] It is further preferred that the system comprising the charging connector and the control unit is provided with a connection area in the housing, in which the charging contacts are galvanically conductively connected to electrical lines leading away from the charging connector, wherein the

[0028] Charging contacts have a recess in the connection area in which the cooling element is located. This recess allows for a large contact area between the charging contact and the cooling element.

[0029] In this case, the connection area of ​​the charging connector is the area of ​​the charging connector in which the charging contacts are galvanically connected to electrical lines leading away from the charging connector.

[0030] In principle, the system comprising the charging connector and the control unit can be provided with only one cooling element. However, according to a preferred embodiment of the invention, the system according to the invention comprises a further cooling element, wherein the further cooling element is connected to the control unit and is connected to another of the charging contacts in such a way that the further charging contact can be cooled by means of the cooling element. Specifically, according to a preferred embodiment of the invention, each charging contact is provided with its own cooling element.

[0031] The invention also relates to the use of a previously described system in an electric or hybrid vehicle. The charging connector can be designed according to the European standard IEC 62196 Type 2.

[0032] Furthermore, the invention relates to a method for operating a charging connector for electric and hybrid vehicles, wherein the charging connector

[0033] Charging contacts for contacting corresponding charging contacts of a corresponding charging connector and a cooling element which is coupled to at least one of the charging contacts such that the charging contact can be cooled by means of the cooling element, comprising the following method steps:

[0034] 51 ) Detect whether a charging process is currently taking place,

[0035] 52) Switching on the cooling element only when it has been detected that no charging process is taking place.

[0036] It is crucial that cooling can only take place outside of a charging process. For this purpose, it is recorded whether a charging process is currently in progress. However, this does not mean that cooling always occurs when no charging is taking place. Cooling is started at a time between two consecutive charging processes, preferably in such a way that the minimum achievable temperature is reached when the charging process starts. Cooling preferably takes place in such a way that the minimum achievable temperature is reached immediately before the charging process begins.

[0037] According to a preferred development of the invention, the method comprises the following further method steps:

[0038] 53) Detecting that a charging process is currently taking place or is imminent, and

[0039] 54) Switching off the cooling element when it has been detected that a charging process is currently taking place or is imminent.

[0040]

[0041] More preferably, the method additionally comprises the following steps:

[0042] S1a) Recording a value for a load-specific parameter,

[0043] S2a) Determining a time period after which a charging process is to be expected using the charging-specific parameter,

[0044] S2b) Switching on the cooling element as soon as the determined time period falls below a predetermined time period threshold.

[0045] Here, a charging-specific parameter is recorded, which can be used to determine a time period after which a charging process is to be expected. Switching on the cooling element as soon as the predetermined time period threshold is undershot enables the charging contacts to reach the minimum achievable temperature shortly before the start of the charging process. The term "time period" thus refers to the time interval after which a charging process is to be expected. According to a preferred development of the invention, a respective value for the charging-specific parameter is successively recorded in step S1a. This makes it possible to continuously check whether the time period falls below the predetermined time period threshold, so that the cooling element can be activated at the right moment.

[0046] In principle, various parameters can be provided as charge-specific parameters. However, according to a preferred development of the invention, the charge-specific parameter is a battery charge value, i.e., a value that indicates the remaining charge of the battery. Such a battery charge value correlates directly with the remaining distance that can be covered.

[0047] Distance, which in turn correlates with the duration threshold. Based on the battery charge level, it is possible to determine when a charging process must begin. For the purposes of this invention, the distance can correspond to both a spatial and a temporal distance.

[0048] According to another preferred embodiment of the invention, the charging-specific parameter is the vehicle's position. Based on the vehicle's position, for example, the distance to a charging station to be approached can be determined, so that cooling of the charging contacts begins when the time duration threshold is exceeded.

[0049] According to a further preferred development of the invention, the charging-specific parameter is a time of day. Regular journeys allow the cooling of the charging contacts to be activated depending on the time of day. If a charging process is expected to begin at certain times of day, the cooling of the charging contacts can be carried out accordingly in advance.

[0050] Finally, according to a preferred development of the invention, it is also provided that the charging-specific parameter is a value from the vehicle navigation of an electric or hybrid vehicle, which indicates that the electric or hybrid vehicle is approaching a charging station. In particular, it is provided in this context that the value from the vehicle navigation of an electric or hybrid vehicle indicates the expected arrival time at the charging station and / or the duration until the electric or

[0051] Hybrid vehicle reaches the charging station.

[0052] The invention is described in more detail below with reference to the drawings using preferred embodiments.

[0053] The drawings show

[0054] Fig. 1 schematically shows a system with a charging connector and a control unit according to a preferred embodiment of the invention,

[0055] Fig. 2 shows a connector corresponding to the connector shown in Fig. 1,

[0056] Fig. 3a the charging connector from Fig. 1 in a side view,

[0057] Fig. 3b schematically shows the charging contacts with the cooling elements of the charging connector from Fig. 3a,

[0058] Fig. 4 shows the cooling element shown in Fig. 3b with a convection element in a schematic view,

[0059] Fig. 5 schematically shows the installation of a charging connector according to a preferred embodiment of the invention in the body of an electric or hybrid vehicle and

[0060]

[0061] Fig. 6 is a flowchart for a method according to a preferred embodiment of the invention.

[0062] Fig. 1 schematically shows a system with a charging connector 1 and a control unit 8 according to a preferred embodiment of the invention. This is a charging plug for installation in the vehicle body 17 of an electric or hybrid vehicle 18, as schematically shown in Fig. 5. The present charging connector 1 is essentially and in terms of its plug face a charging plug according to the European standard IEC 62196 Type 2. In addition to AC charging contacts not further provided with reference numerals, the charging connector has

[0063] 1 a protective contact 15, communication contacts 16 and two charging contacts

[0064] 2 for a direct current charge.

[0065] The charging connector 1 is composed of a front housing part 27 and a rear housing part 28. Both housing parts together form the housing 7 of the charging connector 1. The front housing part 27 is connected to the rear housing part 28 by laser welding. The front housing part 27 is the housing part that faces outward when installed in a vehicle body 17 and is intended to receive a corresponding charging connector 4.

[0066] Such a corresponding charging connector 4 is shown in a perspective view in Fig. 2. This is a

[0067] Charging connector for direct current charging, which essentially complies with the European standard IEC 62196 Type 2 in terms of its connector face. For direct current charging, two corresponding charging contacts 3 are provided in a housing 13, which interact with the charging contacts 2 of the charging connector 1 during charging. Specifically, the charging contacts 2 of the charging connector 1 are designed as contact pins, and the corresponding charging contacts 3 of the corresponding charging connector 4 are designed as contact sleeves into which the contact pins can be inserted. The corresponding charging connector 4 also has two communication contacts 16 and a protective contact 15.

[0068] As can be seen in particular from Fig. 3a, the charging connector 1 has a plug-in area in the front housing part 27 and a connection area in the rear housing part 28. The plug-in area is defined as an area in which the charging connector 1, when plugged into the corresponding charging connector 4, overlaps with the corresponding charging connector 4 in the plug-in direction and the charging contacts 2, 3 of the two connectors 1, 4 are in galvanically conductive contact with one another. The connection area is defined as an area in which the charging contacts 2 of the charging connector are galvanically conductively connected to electrical lines 14 that lead from the charging connector 1 to a battery (not shown in detail).

[0069] What is important in the preferred embodiment of the invention described here is that two cooling elements 5, which in this embodiment

[0070] Peltier elements 6 are arranged in recesses 12 of the charging contacts 2. The Peltier elements 6 are arranged with their cold side 10 in the recesses 12, where they make contact. The hot side 9 is located on the side opposite the cold side 10 and is thermally coupled to the vehicle body 17 via heat pipes (not shown). The recesses 12 are arranged in the connection area of ​​the charging connector 1.

[0071] Fig. 3b shows a perspective view of the charging contacts 2 of the charging connector 1, each of which has recesses 12. Each charging contact 2 has a recess 12 in which a Peltier element 6 is arranged. The Peltier elements 6 are connected to the control unit 8 and are controlled by it, 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 connector 1.

[0072] In this context, however, it should be noted that the arrangement of the Peltier elements 6 in the recesses 12 of the heat-conducting element shown in Fig. 3b is indeed very favorable for heat dissipation from the charging contacts 2. However, other arrangements for the Peltier elements 6 are also conceivable.

[0073] From Fig. 4 it can be seen that, as an alternative to the heat dissipation of the Peltier element 6 by heat pipes, a convection element 11 can be arranged directly contacting the hot side 10 of the Peltier element 6. The

[0074] Convection element 11 has a particularly high ratio of its surface to its volume, so that a particularly large surface is available for heat dissipation for convection cooling.

[0075] It has already been mentioned above that the charging connector 1 is used in the form of a built-in plug on the vehicle body 17 of an electric or hybrid vehicle 18. In this context, reference may be made again to Fig. 5, which schematically shows a charging connector 1 installed in a vehicle body 17 of an electric or hybrid vehicle 18.

[0076] Fig. 6 schematically shows a flowchart illustrating the sequence of a method for operating a charging connector 1 for electric and hybrid vehicles 18 according to a preferred exemplary embodiment of the invention. The first step S1 comprises detecting whether a charging process is currently taking place. Subsequently, in a step S1a, a respective value for a charging-specific parameter is successively detected. In this case, the charging-specific parameter is the state of charge of the battery of the electric or hybrid vehicle 18. In a further step S2a, a time period is determined based on the charging-specific parameter after which a charging process is to be expected. Specifically, in this case, the expected residual range is continuously calculated in the form of a time period based on the state of charge of the battery. As soon as the time period falls below a predetermined time period threshold, the cooling element 5 is switched on by the control unit 8 in step S2b.In a further step S3 it is again recorded whether a.

[0077] A charging process is taking place or is imminent. The cooling element 5 is switched off in step S4 if it was detected in step S3 that a charging process is taking place or is imminent.

[0078]

[0079] List of reference symbols

[0080] 1 charging connector

[0081] 2 charging contacts

[0082] 3 corresponding charging contact

[0083] 4 corresponding charging connectors

[0084] 5 Cooling element

[0085] 6 Peltier element

[0086] 7 housings

[0087] 8 Control unit

[0088] 9 Hot side

[0089] 10 Cold side

[0090] 11 Convection element

[0091] 12 recess

[0092] 13 housings

[0093] 14 electrical cable

[0094] 15 Protective contact

[0095] 16 Communication contact

[0096] 17 Vehicle body

[0097] 18 Electric or hybrid vehicle

[0098] 19 Cooling element

[0099] 27 front housing part

[0100] 28 rear housing part

Claims

Patent claims:

1. System with a charging connector (1) for electric and hybrid vehicles (18) and a control unit (8), wherein the charging connector (1) has a housing (7), charging contacts (2) arranged in the housing (7) for contacting corresponding charging contacts (3) of a corresponding charging connector (4), and a cooling element (5) which is coupled to at least one of the charging contacts (2) in such a way that the charging contact (2) can be cooled by means of the cooling element (5), the cooling element (5) is connected to the control unit (8) so that the cooling function of the cooling element (5) can be controlled by means of the control unit (8), and the control unit (8) is configured to activate the cooling function of the cooling element at a time outside of a charging process.

2. The system of claim 1, wherein the time outside of a charging process is a time before a currently scheduled charging process.

3. System according to claim 1 or 2, wherein the cooling element (5) is a Peltier element (6).

4. System according to claim 3, wherein the Peltier element (6) having a hot side (9) and a cold side (10) is connected to the charging contact (2) in a thermally conductive manner with the cold side (9) and the hot side (9) is coupled to the environment in such a way that heat can be dissipated from the charging contact (2) to the environment.

5. System according to claim 3 or 4, wherein the hot side (10) is connected to a convection element (11) in such a way that heat transfer to the environment via the convection element (11) is enabled by convection.

6. System according to one of the preceding claims, wherein the cooling element (5) directly contacts the charging contact (2).

7. System according to one of the preceding claims with a connection area in the housing (7), in which the charging contacts (2) are galvanically conductively connected to electrical lines (14) which lead away from the charging connector (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 connector (1) for electric and hybrid vehicles (18), wherein the charging connector (1) has charging contacts (2) for contacting corresponding charging contacts (3) of a corresponding charging connector (4) and a cooling element (5) which is coupled to at least one of the charging contacts (2) such that the charging contact (2) can be cooled by means of the cooling element (5), comprising the following method steps: 51 ) Detect whether a charging process is currently taking place, 52) Switching on the cooling element (5) only when it has been detected that no charging process is taking place.

9. Method according to claim 8 with the following further method steps: 53) Detecting that a charging process is currently taking place or is imminent, and 54) Switching off the cooling element (5) when it has been detected that a charging process is currently taking place or is imminent.

10. Method according to claim 8 or 9, comprising the further steps: S1a) Recording a value for a load-specific parameter, S2a) Determining a time period after which a charging process is to be expected using the charging-specific parameter, S2b) Switching on the cooling element (5) as soon as the determined time period falls below a predetermined time period threshold.

11. The method according to any one of claims 8 to 10, wherein in step S1a a respective value for the load-specific parameter is successively recorded.

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

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