Power supply system for an electrically driven machine with an internally cooled cable

Abstract

An energy supply system (100) for an electrically driven machine with, an internally cooled cable (10) which has at least one line for electrical current (12) and at least one coolant line (14), wherein the coolant line (14) is separated section by section from the line for electrical current (12), and a connection device (20) arranged and / or integrated on the electrically driven machine for the internally cooled cable, which has a contacting device (22) and a coolant guide (24) and which is designed to be mechanically coupled to a connection element (16) of the internally cooled cable, wherein the contacting device is designed to electrically contact at least one conductor for electric current when the connection device is mechanically coupled to the cable's connection element, wherein the power supply system is configured to allow a coolant transfer from a coolant line section of the internally cooled cable, separated from the electrical current line, to the coolant guide of the connector, or from the coolant guide of the connector to the coolant line section of the internally cooled cable, separated from the electrical current line, when the connector element of the cable is mechanically coupled to the connector, and wherein the coolant guide (24) of the connection device (20) forms a coolant circuit with at least one inlet and at least one outlet, wherein the coolant circuit is returned from the connection device (20) of the electrically driven machine to the coolant line (14).

Description

[0001] This document describes a power supply system and an associated method for an electrically driven machine. The power supply system includes at least one internally cooled cable.

[0002] Machines powered by electrical energy have cable connections for supplying electrical current. In particular, machines that cannot or should not be permanently installed and operated, for example, motor vehicles, also have a connection device for detachable coupling with a power cable and a storage device for electrical energy, for example, a battery.

[0003] In order to charge the storage device of a non-stationary, electrically powered machine in a time- and resource-efficient manner, and thus to establish a ratio of usage and charging time acceptable for mobile operation, the storage devices are usually charged with high charging powers, especially with high charging currents.

[0004] Both the cable used to charge the machine and the machine itself can become very hot during charging. However, heating of the cable and the machine is undesirable, as it negatively impacts their handling by the operator and increases electrical resistance, thus increasing the power loss of the charging cable and the machine's connection device.

[0005] In particular, undesirable heating can occur at an electrical contact point between the charging cable used and the connection device of an electrically driven machine, since the electrical resistance is higher here than within a single-piece electrical conductor, for example within an electrical line of the cable.

[0006] To counteract this problem, it is known to cool the connection device of an electrically driven machine with a coolant, for example, a cooling liquid. An example of this is disclosed in document EP 3 766 726 A1.

[0007] One disadvantage is that, in addition to the actual charging cable, further cables for supplying and removing coolant must be installed on the electrically driven machine and removed again after charging, or that, in the case of an integrated cooling system, the machine must be at least partially continuously operated during the charging process and cannot be completely switched off.

[0008] A second disadvantage is that the electrically conductive connection between the electrical conductor of a charging cable and the machine's connection device is always also a thermally conductive connection. A coolant circuit in the connection device therefore not only dissipates heat from the electrical contact point between the charging cable and the connection device, but also from the cable end facing the machine. The coolant circuit for the connection device must therefore be very efficient, and this creates an undesirable temperature gradient and thus resistance gradient within the cable itself, leading to an inhomogeneous distribution of power losses within the cable.

[0009] Cables with electrical conductors and integrated coolant lines are also known, for example from documents US 9 287 646 B2, DE 10 2017 115 241 A1, DE 10 2019 114 765 B3, DE 199 21 310 A1 and DE 10 2020 117 588 A1.

[0010] US 9,287,646 B2 relates to a method and an electrical connection for providing electrical power. The electrical connection includes an electrical plug connected to an electrical conductor assembly, wherein the electrical plug and the electrical conductor are actively cooled by means of a cooling medium. The active cooling is provided by passing the medium substantially along a length of the electrical conductor assembly and through the electrical plug.

[0011] DE 10 2017 115 241 A1 relates to a charging cable system with cooling. The charging cable system comprises a charging cable with several individual conductors running within the charging cable and a cable connector for connecting the charging cable to the energy storage device of an electrically powered vehicle. At least one cooling channel runs within the charging cable, through which a cooling medium is conveyed to the cable connector. Furthermore, the cable connector includes valves for returning the cooling medium to the charging cable.

[0012] DE 10 2019 114 765 B3 relates to a charging cable arrangement for charging a traction battery of an electric vehicle. The charging cable arrangement has a charging cable which has at least one electrical conductor and at least one cooling line, and a charging plug with a charging plug housing arranged at the end of the charging cable, wherein the charging plug comprises a connector element and a cooling line coupling element.

[0013] One disadvantage of internally cooled cables, however, is their incompatibility with the cooling system of the connectors, further increasing the installation effort for charging. In particular, separate coolant circuits must be set up and operated for the cables. Furthermore, synchronizing the cooling capacity of the internally cooled cables with that of the connectors is difficult, meaning that despite continuous cooling of the various system components, an undesirable temperature gradient, and thus resistance gradient, can persist in the vicinity of the connectors.

[0014] Therefore, there is a need for an improved energy supply system for an electrically driven machine that overcomes the disadvantages described above.

[0015] Such a system is defined by claim 1. The further claims define advantageous embodiments as well as a method for supplying an electrically driven machine with operating energy.

[0016] A power supply system for an electrically driven machine has an internally cooled cable, which includes at least one conductor for electrical current and at least one coolant line for a liquid or gaseous coolant, and a connection device for the internally cooled cable, which includes a contacting device and a coolant guide. The connection device is configured to be mechanically coupled to a terminal element of the internally cooled cable. The contacting device is configured to electrically contact the at least one conductor for electrical current when the connection device is mechanically coupled to the terminal element of the cable.

[0017] Mechanically coupled means that the connection device and the cable connection element are arranged in such a way that they cannot detach from each other without an external force and are connected to each other to form a charging operation arrangement.

[0018] In other words, the connection device can be designed to receive the terminal element of the internally cooled cable and to electrically contact the conductor for electrical current, for example via the terminal element, which may be made of an electrically conductive material. The terminal element may, for example, have at least one metal pin that can be inserted into a corresponding recess in the connection device. The connection device can be designed such that a terminal element coupled to and / or inserted into it can only be removed, i.e., separated from the connection device, against pressure resistance.

[0019] Furthermore, the power supply system is designed to allow the transfer of a liquid or gaseous coolant from the coolant line of the internally cooled cable to the coolant guide of the connection device or from the coolant guide of the connection device to the coolant line of the internally cooled cable, if the connection device is mechanically coupled to the connection element of the cable.

[0020] In other words, coolant can be exchanged between the internally cooled cable and the connector and / or coolant can be introduced from the cable into the connector and / or discharged from the connector into the cable if the connector is mechanically coupled to the cable's connector element.

[0021] The connector can thus be supplied with coolant via the cable. A separate coolant supply for the connector is therefore unnecessary, as is the provision of a cooling system integrated into the machine. Furthermore, by connecting the coolant supply of the internally cooled cable and the coolant supply of the connector, separate control or regulation, as well as the synchronization of two or more different cooling circuits, is eliminated. Since the electrical conductor of the internally cooled cable and the connector can be cooled by the same coolant, the occurrence of an undesirable temperature gradient, and thus resistance gradient, within the cable and in the area of ​​the connector can also be avoided.

[0022] The electrically powered machine can be, in particular, a motor vehicle, for example an electrically powered passenger car or truck, or an electrically powered two-wheeled vehicle, for example an electrically powered motorcycle.

[0023] According to the invention, the connection device for the internally cooled cable is arranged on and / or integrated into the electrically driven machine. The connection device can be an integral part of the machine or be connected to it in a modular manner, i.e., detachably and / or interchangeably.

[0024] One advantage here is that a coolant guide arranged integrally or detachably in or on the driven machine can be supplied with a liquid or gaseous coolant via the coolant line of the internally cooled cable.

[0025] Optionally, the connection device may include a storage device for electrical energy, wherein the connection device for the internally cooled cable may be configured to charge the storage device with electrical energy supplied through the line for electrical current of the internally cooled cable when the connection device is mechanically coupled to the connection element of the cable.

[0026] The storage device for electrical energy can be, for example, a battery. In one variant of the energy supply system, the storage device for electrical energy can be the energy storage system of an electrically powered vehicle.

[0027] Furthermore, the connection device can have at least one locking element designed to mechanically fix the internally cooled cable, in particular the connection element of the internally cooled cable, and / or to connect the coolant line of the internally cooled cable and the coolant guide of the connection device, so that a transfer of coolant from the coolant line to the coolant guide and / or a transfer of coolant from the coolant guide to the coolant line is allowed.

[0028] The locking element can be a closure, in particular a screw-on closure, a fastening device, a locking mechanism or a similar element designed to fix the internally cooled cable to the connection device after its coupling, so that it can only be removed from the connection device after a manual release or unlocking of the locking element by an operator.

[0029] One advantage of this is that the operational reliability of the power supply system can be increased during a power supply process, and in particular, it can counteract the unintentional detachment of the internally cooled cable from the connection device during a power supply process.

[0030] In one variant, the power supply system can have a coolant pump which is designed to pump a coolant, in particular liquid or gaseous, into the at least one coolant line of the internally cooled cable and / or into the coolant guide of the connection device and / or to pump it out of the at least one coolant line of the internally cooled cable and / or from the coolant guide of the connection device.

[0031] The coolant pump can be integrated as part of the coolant line or as part of the connection device, or it can be provided separately from the coolant line and the connection device. The coolant pump can be configured to be coupled and / or modularly connected to the coolant line and / or the connection device. The coolant pump can be directly or indirectly coupled and / or connected to the electrical power supply of the internally cooled cable. The coolant pump can be configured to be supplied with operating power directly or indirectly through the electrical power supply of the internally cooled cable.

[0032] One advantage of the coolant pump is that it can move the coolant through the internally cooled cable and / or through the connection device, thereby dissipating heat from the internally cooled cable and / or the connection device.

[0033] According to the invention, the coolant guide of the connection device forms at least one coolant circuit with at least one inlet and at least one outlet. The at least one inlet and / or the at least one outlet can be configured to be connected to the coolant line of the internally cooled cable, so that a flow of coolant from the coolant line into the coolant guide and / or a flow of coolant from the coolant guide into the coolant line is permitted when the connection device is mechanically coupled to the cable's connection element.

[0034] Optionally, the internally cooled cable may have at least two coolant lines. A first coolant line may be configured to connect to the coolant circuit inlet of the connector if the connector is mechanically coupled to the cable's connector. A second coolant line may be configured to connect to the coolant circuit outlet of the connector if the connector is mechanically coupled to the cable's connector.

[0035] One advantage here is that the internally cooled cable can thus form a supply and a return line for a coolant circuit within the connection device.

[0036] Another advantage of an internally cooled cable with at least two coolant lines is that the temperature gradient within the cable can be reduced by having a return and supply line for the coolant. The coolant, heated by the heat dissipated from the cable and / or the connector, can warm those parts of the cable that are being cooled more effectively by a still-warm supply of coolant as it exits the cable. Therefore, by having the coolant flow back and forth through the same cable, a more uniform heat distribution within the cable can be achieved.

[0037] In a further development, the energy supply system can include at least one temperature sensor and / or at least one control device. The temperature sensor can be arranged, for example, on the internally cooled cable, in particular on the at least one line for electrical current and / or on the at least one coolant line, or on the connection device, in particular on the contacting device and / or on the coolant guide.

[0038] The control device can be configured to control or regulate a coolant flow through the coolant line and / or through the coolant guide based on a detection by at least one temperature sensor, in particular by controlling and / or regulating the coolant pump.

[0039] One advantage of the temperature sensor and / or the control device is that the amount of coolant supplied to the power supply system and / or the temperature of the coolant supplied to the power supply system can be influenced depending on the actual cooling requirement of the power supply system.

[0040] The temperature sensor and / or control device can also be used to respond to time-varying cooling requirements of the power supply system. For example, the internally cooled cable and / or the connection device may heat up during a continuous power supply operation. This increasing temperature can be detected by the temperature sensor and / or the control device, and the amount of coolant supplied and / or the temperature of the coolant supplied to the power supply system can be adjusted accordingly.

[0041] An electrically driven machine, in particular a motor vehicle, may have one of the energy supply systems described above. The connection device for the internally cooled cable and / or the electrical energy storage device and / or the coolant pump may be designed as components of the electrically driven machine. The electrically driven machine may, in particular, be a motor vehicle, for example an electrically driven passenger car or truck, or an electrically driven two-wheeled vehicle, for example an electrically driven motorcycle.

[0042] A method for supplying an electrically driven machine with operating energy comprises the following steps: - Providing an internally cooled cable that has at least one electrical current line and at least one coolant line. - Providing at least one connection device for the internally cooled cable, which has a contacting device and a coolant guide and is designed to be mechanically coupled to a connection element of the internally cooled cable. - Mechanical coupling of the cable's connection element with the connection device, so that the contacting device electrically contacts at least one line for electrical current and allows coolant exchange between the coolant line of the internally cooled cable and the coolant guide of the connection device.

[0043] Further features, properties, advantages, and possible variations will become clear to a person skilled in the art from the following description, which refers to the accompanying schematic illustrations. All described and / or schematically depicted features, individually or in any combination, illustrate the subject matter disclosed herein. The illustrations are simplified schematically and, in particular, not to scale.

[0044] The illustrations each schematically depict an energy supply system for an electrically driven machine. Fig. Figure 1 schematically shows an example of a power supply system for an electrically driven machine with an internally cooled cable and a connection device. Fig. Figure 2 schematically shows an example of a power supply system for an electrically driven machine with two internally cooled cables. Fig. Figure 3 schematically shows an example of a power supply system for an electrically driven machine with an internally cooled cable that has two coolant lines.

[0045] Unless explicitly stated otherwise, identical or functionally comparable components and parts are shown in the schematic diagrams. Fig. Items 1 to 3 are labelled with matching reference numerals.

[0046] The Fig. Figure 1 schematically shows an example of an energy supply system 100 for an electrically driven machine with an internally cooled cable 10 and a connection device 20.

[0047] The internally cooled cable 10 has at least one conductor for electrical current 12, which is electrically connected to a terminal element 16. In the Fig. In the example shown, the connecting element 16 is electrically conductive. Furthermore, the connecting element 16 and the conductor 12 are connected in the Fig. In the example shown, the cable is formed in one piece; however, this is not necessary in all embodiments. In other power supply systems not shown, the cable may also have a connection element that is not formed in one piece with the conductor carrying the electrical current.

[0048] Furthermore, the internally cooled cable 10 has a coolant line 14, which is designed to conduct a liquid or gaseous coolant through the cable 10 and thereby dissipate the heat caused by the electrical resistance of the line 12 in the event of the passage of electric current.

[0049] In the Fig. In the example shown, the coolant line 14 penetrates the insulation of the internally cooled cable 10 at at least one point and runs, at least in sections, separated from the electrical conductor 12, beyond the insulation of the cable that surrounds the electrical conductor 12. However, this is not necessary in all embodiments. In other power supply systems not shown, the coolant line 14 can also be surrounded or at least partially enclosed by the inner or outer insulation of the cable and / or one or more electrical conductors up to a transition point to a coolant line of a connection device.

[0050] The connecting element 16 of the internally cooled cable 10 is designed to be mechanically coupled to a connecting device 20 of the power supply system 100. In the Fig. In the example shown, the connecting element 16 is designed to be arranged in a correspondingly shaped recess in the connecting device 20. In other embodiments not shown, the connecting element can, for example, also have a recess into which a correspondingly shaped contacting device of the connecting device can be inserted.

[0051] The connecting device 20 of the in the Fig. The power supply system 100 shown in Figure 1 has a contacting device 22 configured to electrically contact the current-carrying conductor 12 of the internally cooled cable 10 when the terminal element 16 is coupled to or connected to the terminal device 20. In the example shown, the contacting device 22 is configured to contact the current-carrying conductor 12 through the electrically conductive terminal element 16.

[0052] Furthermore, the connection device 20 of the power supply system 100 includes the coolant guide 24. The coolant guide 24 is formed by the walls of the connection device 20 and is configured to guide a liquid or gaseous coolant along a predetermined path through the connection device. This allows heat, in particular heat caused by the flow of electric current, to be dissipated from the connection device 20. In other words, the coolant guide 24 is formed by one or more coolant channels within the connection element 20, each of which is configured to guide an externally supplied liquid or gaseous coolant for cooling the connection device 20.

[0053] The coolant line 14 of the internally cooled cable 10 is designed to be connected to the coolant guide 24 of the connection device 20 when the connection element 16 is placed in the correspondingly formed recess in the connection device 20. The Fig. The coolant line 14 shown can, for example, be connected to the coolant guide 24 by means of a plug connection. Alternatively or additionally, the power supply system can also have one or more screw, snap-in, and / or magnetic devices and / or similar fastening elements (not shown) for connecting the coolant line 14 to the coolant guide 24. In other words, the power supply system 100 at least permits the passage of coolant from the coolant line 14 of the internally cooled cable 10 to the coolant guide 24 of the connection device 20, i.e., it enables it when the connection element 16 is mechanically coupled to the connection device 20.

[0054] What's next in the Fig. As shown schematically in section 2, two internally cooled cables 10, for example two of the ones in the Fig. 1 shown internally cooled cable, and a connection element 20 a coolant circuit is produced which enables both the cooling of the cable 10 and the connection element 20, wherein both devices are cooled by a common coolant.

[0055] As in the Fig. As shown schematically in Figure 2, the power supply system 100 can include a coolant pump 40 which pumps a coolant, for example a liquid, into the coolant line 14 of the internally cooled cable 10. The pumped-in coolant can dissipate heat from both the cable itself and the connection device 20 when the internally cooled cable 10 is connected to the connection device 20.

[0056] As in the Fig. As shown schematically in Figure 2, the coolant pump 40 can, for example, be integrated into an energy supply device 50, which, in addition to providing electrical operating energy for the electrically driven machine, can also supply a coolant reservoir. Optionally, the energy supply device 50 and / or the coolant pump 40 can also include a heat exchanger (not shown) for dissipating the heat absorbed by the coolant from the coolant circuit.

[0057] The Fig. Figure 3 schematically shows an alternative energy supply system 100 with an internally cooled cable 10 and a connection device 20. In the Fig. In the example shown in section 3, the internally cooled cable 10 has at least two coolant lines 14, both of which are connected to the coolant guide 24 of the connection device 20, with the first of the coolant lines 14 serving as the supply line for the coolant and the second of the coolant lines 14 serving as the return line for the coolant. This means that only a single cable is required to create a coolant circuit. Furthermore, the return flow, which is already carried by the line for electrical current 12 (in the Fig. 2 and Fig. 3 (not shown for clarity) and the coolant heated by the connection device 20 heats those parts of the cable 10 which are cooled most by the coolant flowing into the cable and which is still unheated, so that a uniform heat distribution within the cable 10 is further improved.

[0058] How to proceed schematically in the Fig.As shown in Figure 3, the coolant pump 40 can also be integrated directly into the internally cooled cable 10 or be designed as an integral part of the cable 10. In this case, the coolant pump 40 can be supplied with electrical operating energy from the power supply device 50, in particular via the electrical current line 12 of the cable 10.

[0059] It is understood that the exemplary embodiments described above are not exhaustive and do not limit the subject matter disclosed herein. In particular, it is evident to the person skilled in the art that they can combine the described features in any way they wish and / or omit various features without deviating from the subject matter disclosed herein.

Claims

[1] An energy supply system (100) for an electrically driven machine with, an internally cooled cable (10) which has at least one line for electrical current (12) and at least one coolant line (14), wherein the coolant line (14) is separated section by section from the line for electrical current (12), and a connection device (20) arranged and / or integrated on the electrically driven machine for the internally cooled cable, which has a contacting device (22) and a coolant guide (24) and which is designed to be mechanically coupled to a connection element (16) of the internally cooled cable, wherein the contacting device is designed to electrically contact at least one conductor for electric current when the connection device is mechanically coupled to the cable's connection element, wherein the power supply system is configured to allow a coolant transfer from a coolant line section of the internally cooled cable, separated from the electrical current line, to the coolant guide of the connector, or from the coolant guide of the connector to the coolant line section of the internally cooled cable, separated from the electrical current line, when the connector element of the cable is mechanically coupled to the connector, and wherein the coolant guide (24) of the connection device (20) forms a coolant circuit with at least one inlet and at least one outlet, wherein the coolant circuit is returned from the connection device (20) of the electrically driven machine to the coolant line (14). [2] Energy supply system (100) according to claim 1, wherein the electrically driven machine is a motor vehicle. [3] Energy supply system (100) according to claim 1 or 2, further comprising a storage device (30) for electrical energy, wherein the connection device (20) for the internally cooled cable is configured to charge the storage device with electrical energy supplied through the line for electric current (12) of the internally cooled cable (10) when the connection device is mechanically coupled to the connection element (16) of the cable. [4] Energy supply system (100) according to one of the preceding claims, wherein the connection device (20) has at least one locking element which is configured to mechanically fix the internally cooled cable (10), in particular the connection element (16) of the internally cooled cable, and / or to connect the coolant line (14) of the internally cooled cable and the coolant guide (24) of the connection device to each other, so that a transfer of coolant from the coolant line to the coolant guide and / or a transfer of coolant from the coolant guide to the coolant line is released. [5] Energy supply system (100) according to one of the preceding claims, further comprising a coolant pump (40) which is configured to pump a fluid, in particular liquid, coolant into the at least one coolant line (14) of the internally cooled cable (10) and / or into the coolant guide (24) of the connection device and / or to pump out of the at least one coolant line of the internally cooled cable and / or from the coolant guide of the connection device. [6] Energy supply system (100) according to one of the preceding claims, wherein the at least one inlet and / or the at least one outlet is configured to be connected to the coolant line (14) of the internally cooled cable (10), so that a transfer of coolant from the coolant line to the coolant guide and / or a transfer of coolant from the coolant guide to the coolant line is released when the connection device is mechanically coupled to the connection element (16) of the cable. [7] Energy supply system (100) according to the preceding claim, wherein the internally cooled cable (10) has at least two coolant lines, wherein a first coolant line is provided to be connected to the inlet of the coolant circuit of the connection device (20) when the connection device is mechanically coupled to the connection element (16) of the cable, and a second coolant line is provided to be connected to the outlet of the coolant circuit of the connection device when the connection device is mechanically coupled to the connection element of the cable. [8] Energy supply system (100) according to any of the preceding claims, further comprising, at least one temperature sensor and / or at least one control device, wherein the temperature sensor is arranged on the internally cooled cable (10), in particular on the at least one line for electrical current (12) and / or on the at least one coolant line (14), or on the connection device (20), in particular on the contacting device (22) and / or on the coolant guide (24), and / or wherein the control device is designed to regulate a coolant flow through the coolant line and / or through the coolant guide based on a detection by at least one temperature sensor, in particular by controlling and / or regulating the coolant pump (40). [9] comprising an electrically powered machine, in particular a motor vehicle an energy supply system (100) according to any of the preceding claims, wherein the connection device (20) for the internally cooled cable and / or the storage device (30) for electrical energy and / or the coolant pump (40) are designed as components of the electrically driven machine. [10] A method for supplying an electrically driven machine with operating energy comprises the following steps: - Providing an internally cooled cable (10) comprising at least one electrical current conductor (12) and at least one coolant line (14), wherein the coolant line (14) is sectionally separated from the electrical current conductor (12); and - Providing at least one connection device (20) arranged and / or integrated on the electrically driven machine for the internally cooled cable, which has a contacting device (22) and a coolant guide (24), wherein the coolant guide (24) of the connection device (20) forms a coolant circuit with at least one inlet and at least one outlet, wherein the coolant circuit is returned from the connection device (20) of the electrically driven machine to the coolant line (14), and which is configured to be mechanically coupled to a connection element (16) of the internally cooled cable; - Mechanical coupling of the cable's connection element with the connection device, so that the contacting device electrically contacts the at least one conductor for electrical current and a coolant exchange is enabled between a coolant line section of the internally cooled cable separated from the conductor for electrical current and the coolant guide of the connection device.

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