Energy transmission device, watercraft, energy transmission system and operating procedure for an energy transmission system

Abstract

Energy transfer device (30) comprising at least: an energy supply facility (40); a primary coil (50) electrically connected to the power supply unit; a stationary fixing element (70) comprising ferromagnetic material, wherein the primary coil (50) can be brought into an electromagnetic functional connection with the stationary fixing element (70), wherein the device comprises a rotatably mounted L-shaped profile (60) and a web (80), and that the bridge (80) and the L-shaped profile (60) comprise a ferromagnetic material, and that a rotational position of the L-shaped profile (60) can be assumed in which at least the L-shaped profile (60), the stationary fixing element (70) and the web (80) form a magnetic circle.

Description

[0001] The invention relates to a device for energy transmission according to claim 1.

[0002] Societal pressure and ever-increasing emissions requirements are driving the electrification of vehicles. The vehicle's drive system consists of at least an electric motor and a secondary energy storage system. While public discussions primarily focus on motor vehicles, electrification is not limited to this type of vehicle. Watercraft are also increasingly coming under scrutiny for electrification.

[0003] Such a watercraft can be powered using conductive charging methods. The disadvantage of conductive charging methods for watercraft lies primarily in the environmental conditions. Condensation buildup in the connectors leads to oxidation of the electrical contact surfaces. Especially in coastal areas, the saline environment has a negative impact on these electrical contacts.

[0004] Alternatively, inductive charging methods are known, though they are of minor practical significance. For example, document CN207403894U shows a charging station for watercraft mounted on a circular island. This island is connected to a landing structure, such as a quay, via a connecting bridge. Watercraft are secured using bollards located on the island. For charging, a mobile charging device containing a primary coil is positioned over a secondary coil on the ship's deck using a positioning pin. Energy is transferred between the mobile charging device and the watercraft via the primary and secondary coils. The primary coil is powered by a power distributor located on the circular island.

[0005] Document CN110341505A describes another concept for the inductive charging of watercraft. In this concept, a module with a primary coil is located on a landing structure, such as a dock. A module with a secondary coil is attached to the hull of the watercraft. Energy is inductively transferred from the landing structure to the watercraft via these two modules. For the energy transfer to occur, the watercraft must be positioned precisely.

[0006] US 2014 / 0 176 059 A1 discloses a magnetic connection device for charging electric vehicles. DE 24 02 069 A discloses a connector with inductive coupling. EP 0 926 690 A1 discloses a split transformer and a transmission control unit incorporating the split transformer. US 2012 / 0 106 210 A1 discloses a multiphase current transformer and integrated choke. DE 10 2016 123 173 A1 discloses a single-phase permanent magnet motor. US 2020 / 0 075 238 A1 discloses a method for manufacturing a module. DE 10 2017 117 418 A1 discloses a primary-side charging device, a secondary-side charging device, and a method for charging a battery for an electric vehicle.

[0007] Due to the lack of focusing and guiding of the magnetic field lines in the prior art embodiments of inductive charging methods, stray losses occur, which reduce the efficiency of the energy transfer. The object of the present invention is therefore to increase the efficiency of an inductive charging device.

[0008] This problem is solved according to the invention by a device for energy transmission having the features according to claim 1. Further advantageous embodiments are specified in the dependent claims.

[0009] According to the present invention, a device for energy transmission is provided. This includes, among other things: - an energy supply facility; - a primary coil electrically connected to the power supply unit; - a stationary fixing element comprising ferromagnetic material.

[0010] The invention is characterized in that the stationary fixing element can be brought into an electromagnetic operative connection with the primary coil.

[0011] The stationary fixing element made of ferromagnetic material focuses the magnetic field lines that result from current flowing through the primary coil. This focusing of magnetic field lines reduces magnetic stray losses. Consequently, the efficiency of the energy transmission system for watercraft is advantageously increased.

[0012] A power supply device is any device that can be used to supply power to electrical components. The power supply device can be supplied with electrical energy via a connection point, either directly or indirectly. The provision of electrical energy can be achieved through a power line between the power supply device and a conversion point for any form of energy into electrical energy, preferably in the form of a power distribution network.

[0013] Furthermore, energy can be supplied via a power line between the energy supply unit and a mobile charging station for motor vehicles. An unlimited amount of energy is available through energy distribution via a power distribution network. Additionally, the energy supply unit can be operated within a smart grid.

[0014] Alternatively, a device for the direct conversion of energy, such as a generator, can be located at a connection point of the energy supply system via a direct or indirect connection. In another variant, the energy supply can be provided by a wind turbine, or by an offshore or onshore wind farm. This allows for an energy supply independent of a power distribution network.

[0015] At another connection point, an electrical component may be directly or indirectly connected to the power supply facility.

[0016] A primary coil is an electrical component comprising at least one piece of electrically conductive metallic material. In one embodiment, a primary coil has at least one turn. Furthermore, the conductor cross-section of the coil material can have any shape, preferably an approximately circular shape.

[0017] By winding the coil material, any desired winding configuration for the primary coil can be generated, for example, an approximately circular winding configuration. In a preferred embodiment, the winding configuration of the coil has the cross-section of the ferromagnetic component to which the primary coil can be attached. The cross-section of the component can be described by a polygon and / or an approximately circular cross-section. By achieving an approximately identical cross-section between the winding configuration of the primary coil and the ferromagnetic component, the resulting air gap between the two can be minimized. This reduces reluctance and further increases the efficiency of the energy transfer.

[0018] An electrical connection is understood to be a detachable, conditionally detachable, or permanent contact between two electrically conductive components. Preferably, the electrical connection is designed such that the contact resistance between the two electrical components is as low as possible in order to transmit electrical energy with minimal power loss.

[0019] A stationary fixing element serves to restrict the degrees of freedom of a watercraft, thus ensuring a defined target position of the watercraft in the water. In addition to restricting the degrees of freedom, the fixing element also serves to concentrate magnetic field lines, thereby enabling functional integration. This functional integration reduces the number of components required and creates an electromagnetic connection between the primary coil and the stationary fixing element.

[0020] For an electromagnetic connection to be established between a fixing element and a primary coil, a current flow through the primary coil is required. In one embodiment, the fixing element can be enclosed by at least one turn of the primary coil. The ferromagnetic material of the fixing element further focuses the magnetic field lines, thereby minimizing stray losses and thus efficiency losses. An electromagnetic connection is understood to be a magnetic interaction between at least two bodies caused by current flow. Both bodies are penetrated by at least one common magnetic field line.

[0021] For the following sections of the description, a Cartesian coordinate system is introduced. The xy-plane of the Cartesian coordinate system lies on the surface of a landing structure. A landing structure is a shoreline structure that can be used as a mooring point for watercraft. The z-direction of the Cartesian coordinate system points towards the horizon.

[0022] In one embodiment, the energy transmission device includes a stationary fixing element, which can be designed as an I-shaped profile, for example, in the form of a semi-finished product. An I-shaped embodiment includes all geometric bodies whose cross-sections can be described by a polygon and / or an approximately circular cross-section. The cross-section can be described by the xy-plane of the Cartesian coordinate system. Such a cross-section can be produced using standardized manufacturing processes, resulting in low procurement costs.

[0023] Furthermore, the dimensions of an I-shaped body in one of the spatial directions of the Cartesian coordinate system are significantly larger than in the remaining spatial directions, for example in the z-direction.

[0024] According to the invention, the energy transmission device comprises, in addition to the stationary fixing element, a rotatably mounted L-shaped profile and a web. Both the web and the L-shaped profile comprise ferromagnetic material.

[0025] The geometric shape of an L-shaped profile can be formed by combining two previously described I-shaped profiles. The I-shaped profiles are arranged such that the vectors characterizing the largest dimension of the I-shaped profile are coplanar to each other. Furthermore, the I-shaped profiles are preferably arranged to result in planar contact between the two profiles.

[0026] In this embodiment, the primary coil can enclose the rotatably mounted L-shaped profile. A current flow within the primary coil results in an electromagnetic connection between the stationary fixing element, the rotatably mounted L-shaped profile, and the bridge. According to the invention, the L-shaped profile can assume a rotational position in which at least the L-shaped profile, the fixing element, and the bridge form a closed magnetic circuit. By forming this closed magnetic circuit, the magnetic flux can be directed precisely between the primary and secondary coils, thereby reducing stray losses and further increasing the efficiency of the energy transfer.

[0027] A rotatable bearing is understood to mean, at least for a certain rotational range, an unrestricted rotational degree of freedom in the Cartesian coordinate system, whereas remaining rotational degrees of freedom are restricted. The unrestricted rotational degree of freedom is preferably chosen such that the rotation axis vector is collinear with the z-axis of the Cartesian coordinate system.

[0028] The web serves to connect the bearing point of the L-shaped profile to the stationary fixing element. In a preferred embodiment, the web can be designed as an I-shaped profile. In this preferred embodiment, a planar contact is desired at the connection points of the web.

[0029] The rotational position for forming a magnetic circuit with minimal reluctances results from aligning the L-shaped profile so that the air gap between the stationary fixing element and the L-shaped profile has a minimum value.

[0030] A magnetic circuit is a closed path, or closed loop, of magnetic flux. For a circuit to be closed, at least one magnetic field line must pass through the elements of the magnetic circuit. A magnetic circuit can include ferromagnetic elements, which preferably have a planar connection to each other.

[0031] Another embodiment is characterized in that the ferromagnetic material comprises a laminated metal core and / or a powder metallurgy metal core and / or a ferrite core.

[0032] Laminated metal cores comprise at least two layered sheets of a metallic sheet, preferably with a surface contact area. Using the ferromagnetic material as a solid is not practical for metal cores. The applied, time-varying magnetic field results in eddy currents that would heat the solid material or the metal core. To avoid this undesirable heating, the metal core can be laminated. This design reduces the generation of eddy currents and thus the unwanted heating.

[0033] Powder cores are manufactured using powder metallurgy from ferromagnetic material and an organic and / or inorganic electrically insulating binder. In contrast to solid metal cores, but also compared to laminated metal cores, powder cores exhibit lower eddy current losses at high frequencies because the binder provides particularly high electrical insulation between the metal particles.

[0034] Ferrite cores consist of ferrimagnetic materials. The ferrite grains result in low electrical conductivity. Consequently, ferrite cores are characterized by low metal core losses over a wide frequency range.

[0035] Furthermore, an unused watercraft will be provided. This will include at least: - an on-board electrical system; - a shore-side fixing element; - a secondary coil that can be brought into electrical connection with the vehicle's electrical system and into mechanical connection with the vehicle's mounting element.

[0036] The watercraft is characterized by the fact that the secondary coil can be brought into an electromagnetic functional connection with an off-board fixing element.

[0037] The electromagnetic connection between the secondary coil and an off-board mounting element allows magnetic field lines resulting from current flow through a primary coil to be focused. This focusing of magnetic field lines reduces magnetic stray losses and consequently increases the magnetomotive force (MFR) in the secondary coil. This advantageously further increases the efficiency of the power transmission system for watercraft.

[0038] An electrical system can include electrical wiring, electrical connections, and / or electrical loads. It can provide power to individual electrical loads and / or facilitate the flow of information between them. An electrical load is an electrical component that can use electrical energy as its input. Within the electrical load, energy conversion can occur, for example, from electrical energy to mechanical energy.

[0039] An onboard fixing element is attached to the watercraft, preferably on board. This element can be used to restrict the degrees of freedom of the watercraft. The onboard fixing element establishes a force transmission between the watercraft and the offboard fixing element via an intermediate element, for example, a rope. This force transmission serves to restrict the degrees of freedom of the watercraft.

[0040] A secondary coil is an electrical component comprising at least one piece of electrically conductive metallic material. In a preferred embodiment, the secondary coil has at least one turn. Furthermore, the conductor cross-section of the coil material can have any shape, preferably an approximately circular shape.

[0041] Any desired winding configuration for the secondary coil can be generated by the winding of the coil material, for example, an approximately circular winding configuration. In a preferred embodiment, the winding configuration of the coil has the cross-section of the external mounting element to which it is attached. The cross-section of the external mounting element can be described by a polygon and / or an approximately circular cross-section. By achieving an approximately identical cross-section between the winding configuration of the coil and the external mounting element, the resulting air gap between the two can be minimized. This reduces reluctance and further increases the efficiency of the energy transfer.

[0042] A mechanical connection can be understood as any type of connection that allows force to be mechanically transmitted between two elements. The mechanical connection can be either detachable or permanent.

[0043] An off-board restraint is a restraint located outside the watercraft. Any restraint that serves to restrict the degrees of freedom of a watercraft can be used. In one embodiment, a restraint located on a landing craft is used.

[0044] A preferred embodiment of the watercraft is characterized in that the secondary coil has at least: - a strand for energy transmission; - includes a power transmission strand.

[0045] A power transmission line is permeated by a time-varying magnetic field, which can be generated, for example, by a primary coil. This induces a voltage within the secondary coil. The power transmission line serves to supply electrical energy to the vessel's electrical consumers.

[0046] A force transmission link can be understood as any element that can reliably transmit forces between a watercraft and a landing object. The force transmission link can restrict the degrees of freedom of the watercraft.

[0047] The advantage of this design variant lies in the functional integration of energy and power transmission into a single component. This functional integration also reduces the number of components required.

[0048] The electrical system of the unused watercraft may contain: - a charging device; - a secondary energy storage device; - an electrical consumer; on.

[0049] The on-board electrical system is characterized by the fact that - the secondary coil is in electrical connection with the charging device and / or the electrical consumer; - the charging device is electrically connected to the secondary energy storage system; - the number of turns in the primary and secondary coils is the same or different.

[0050] A charging device is any device that can increase the capacity, i.e., the amount of charge stored, of a secondary energy storage device. A charging device can incorporate various electronic circuits, enabling different charging methods, such as fast charging. Furthermore, a charging device can convert the voltage type, for example, from alternating current (AC) to direct current (DC) and vice versa. The charging device is supplied with electrical energy at one connection point. At another connection point, an electrical component, preferably a secondary energy storage device, can be connected via an electrical connection.

[0051] A secondary energy storage device is an energy storage device whose charge quantity can be reduced multiple times by discharging and increased by charging.

[0052] Different or identical numbers of turns between the primary and secondary coils allow the primary-side voltage to be transformed to the voltage value of the watercraft's electrical system.

[0053] Furthermore, an unused energy transmission system will be provided. This includes at least: - a device for energy transmission; - a watercraft.

[0054] The energy transfer system is characterized in that the offboard fixing element of the watercraft is the stationary fixing element of the energy transfer device.

[0055] The energy transmission system combines an energy transmission device and a watercraft. Its unique feature is that a shared, stationary fixing element is an integral part of both the watercraft and the energy transmission device.

[0056] One embodiment of the energy transfer system is characterized in that bidirectional energy transfer is possible between the energy supply unit of the energy transfer device and the secondary energy storage unit of the watercraft.

[0057] Bidirectional energy transfer refers to the transfer of electrical energy between a power supply unit and a secondary energy storage device. This allows the energy transfer system to be operated within a smart grid.

[0058] Furthermore, an unclaimed method for controlling an energy transmission system is provided.

[0059] Further advantages, advantageous embodiments, and developments of the invention are presented in the following description with reference to the figures. Specifically, it shows: Fig. 1 a preferred embodiment of the energy transmission system 10 comprising an energy transmission device 30, a landing craft 20 and a watercraft 90. Fig. 2 - 4 the components involved in the magnetic circuit. This shows Fig. 2 the opened and Fig. 3 the closed magnetic circuit, wherein in Fig. 3 further shows a Tau 110 and a secondary coil 130. Furthermore, it forms Fig. 4 a top view of the Fig. 3 from.

[0060] Fig. Figure 1 illustrates a preferred embodiment of an energy transmission system 10 comprising an energy transmission device 30, a landing craft 20 and a watercraft 90.

[0061] The energy transmission system 10 can be operated in two modes. In the first mode, an energy supply unit 40 provides electrical energy for inductive energy transfer from the landing craft 20 to the watercraft 90. In the second mode, the energy supply unit 40 feeds electrical energy into an energy distribution network, such as the public power grid, a secondary energy storage device 160 of the watercraft 90. The electrical energy transfer from the secondary energy storage device 160 to the energy supply unit 40, and thus between the watercraft 90 and the energy transmission device 30, is also inductive.

[0062] Regardless of the operating mode, the degrees of freedom of the watercraft 90 are restricted by means of a rope 110. The force is transmitted between a berth-side fixing element 100 of the watercraft 90 and a fixing element 70 located on the landing structure 20. The landing structure can be understood as a berth for watercraft, in the illustrated embodiment in the form of a quay or pier. In the present embodiment, a cleat is used as the berth-side fixing element 100 and a bollard as the fixing element 70. In addition to the rope 110, a secondary coil 130 can also be used to restrict the degrees of freedom; the force is transmitted analogously to the rope 110. The force is transmitted to the secondary coil via a force transmission strand, which in the present embodiment is made of synthetic fibers, for example, in the form of Dyneema.

[0063] In a first operating mode, the charging of the secondary energy storage device, in the form of a high-voltage storage device, is initially carried out with reference to Fig. 1 explained. The supply of electrical energy to the energy transmission system 10 is carried out via the energy transmission device 30.

[0064] The energy transmission device 30 comprises the energy supply unit 40, a primary coil 50, a rotatably mounted L-shaped profile 60, the fixing element 70 and a bridge 80.

[0065] The rotatably mounted L-shaped profile 60, the fixing element 70 and the web 80 comprise ferromagnetic material, which in the embodiment shown results in the form of a powder metallurgically produced metal core.

[0066] The energy supply unit 40 can be supplied with electrical energy at a connection point via several options, either a direct or indirect electrical connection. For example, electrical energy can be provided by direct connection to an energy distribution network or by indirect connection to an energy distribution network via a mobile charging station for motor vehicles, whereby the public electricity grid can be used as the energy distribution network.

[0067] Furthermore, electrical energy can be provided through local energy generation. For this purpose, a generator or a wind turbine, or an offshore or onshore wind farm, can be used, although these are not shown in the corresponding figures. In both cases, the electrical energy supply can be in the form of alternating current.

[0068] The primary coil 50 is located at another connection point, with the connection between the two components being conductive and, for example, achieved by a screw connection. Due to the conductive connection of the two components, the applied alternating voltage results in a current flowing in the primary coil 50. According to the applicable physical laws, this current flow generates a time-varying magnetic field. Since the primary coil 50 encloses the rotatably mounted L-shaped profile 60, the generated magnetic field is amplified due to the ferromagnetic material, and an electromagnetic connection is established between the primary coil 50 and the L-shaped profile 60.

[0069] The magnetic field can be influenced by the output voltage of the power supply unit 40, with a time-varying magnetic field in the high-frequency range being desirable. Key influencing parameters include the voltage type, voltage level, and voltage frequency. In this embodiment, the power supply unit 40 has a preferred configuration for varying these parameters. This configuration includes at least a rectifier, a filter, a DC link, an inverter, and control electronics. This preferred configuration can also be applied to other embodiments.

[0070] The arrangement of the rotatably mounted L-shaped profile 60, the fixing element 70, and the web 80 results in a magnetic circuit with minimal reluctance, provided the rotation angle of the L-shaped profile 60 is selected such that the air gap 170 between the L-shaped profile 60 and the fixing element 70 is at its minimum possible value. The magnetic circuit guides and concentrates magnetic field lines. The fixing element 70 is enclosed by the secondary coil 130, which is thus permeated by the time-varying magnetic field.

[0071] Furthermore, an electromagnetic connection is established between the fixing element 70 and the secondary coil 130, and thus necessarily also between the primary coil 50 and the secondary coil 130. The current flowing through the secondary coil 130 induces an induced voltage in the energy transmission strand of the secondary coil 130. In this embodiment, the energy transmission strand consists of metallic copper material. The number of turns of the secondary coil 130 is selected such that the resulting induced voltage approximately corresponds to the voltage of the electrical system 120 of the watercraft 90.

[0072] The secondary coil 130 is in conductive connection with the on-board network 120 of the watercraft 90 and thus in electrical connection with an electrical consumer 140 and / or a charging device 150.

[0073] An electrical load 140 connected via the secondary coil 130 can be operated using the applied alternating voltage. In the illustrated embodiment, an electrical load can be, for example, an instrument panel, a lighting device in the form of a headlight, an air conditioner, a control device, or a cooling device in the form of a refrigerator and / or freezer, although these are not shown in the figures. Alternatively, the electrical load 140 can be operated with direct current by using an internal rectifier.

[0074] In the present operating mode, the charging device 150 serves to increase the charge capacity of the secondary energy storage device 160. The charging device 150 is supplied with electrical energy from the secondary coil 130 via a connection point. A secondary energy storage device 160 is located at another connection point.

[0075] The charging device 150 incorporates various electronic circuits, enabling different charging methods, such as fast charging. In the illustrated embodiment, the implementation of different charging methods is achieved by the charging device adhering to a preferred design. This design includes at least a rectifier, a filter, a DC link, an inverter, and control electronics. The preferred embodiment can also be applied to other embodiments.

[0076] In a second operating mode, the energy supply device 40 serves the energy transmission device 30 to supply an energy distribution network, for example the public electricity grid and / or another electrical consumer, for example another watercraft and / or motor vehicle, with electrical energy from the secondary energy storage device 160 of the watercraft 90. The additional electrical consumer, in the form of another watercraft or another motor vehicle, is not shown in the figures.

[0077] The electrical connections of the vehicle electrical system 120 are configured analogously to the first operating mode in the second operating mode. During operation, the secondary energy storage device 160 supplies the charging unit 150 with electrical energy. The charging unit 150 converts the connected DC voltage into AC voltage using an inverter. This causes a time-varying current to flow through the secondary coil 130, which in turn generates a time-varying magnetic field. As in the first operating mode, this results in an electromagnetic connection between the secondary coil 130 and the primary coil 50. The time-varying magnetic field induces a voltage in the primary coil 50, which is then converted in the power supply unit 40 to the voltage level and frequency of the grid frequency of the power distribution network being supplied.Finally, the previously converted induced voltage is used to supply an energy distribution network, for example the public electricity grid.

[0078] Fig. 2 shows that in Fig. Figure 1 describes an embodiment with an open magnetic circuit. In this embodiment, the rotatably mounted L-shaped profile 60, the fixing element 70, and the bridge 80 are components of a magnetic circuit. The illustrated rotational position of the L-shaped profile 60 serves to attach the rope 110 to the fixing element 70. Furthermore, the secondary coil 130 can be attached to the fixing element 70.

[0079] Fig. 3 represents the one in Fig. The open magnetic circuit described in section 2 is represented in a closed state. The rotational position of the L-shaped profile 60 is selected such that the air gap 170 between the L-shaped profile 60 and the fixing element 70 assumes the minimum possible value. This results in a closed magnetic circuit with minimal reluctance.

[0080] Fig. 4 shows a top view of the Fig. 3 and illustrates the resulting minimum value of the air gap 170 between L-shaped profile 60 and fixing element 70. Reference symbol list 10 Energy transmission system 20 landing craft 30 Energy transmission device 40 Energy supply facility 50 Primary coil 60 Rotatable L-shaped profile 70 Fixed fixing element 80 Bridge 90 Watercraft 100 Side-side fixing element 110 Tau 120 On-board power supply 130 Secondary coil 140 Electrical consumers 150 charging equipment 160 Secondary energy storage 170 air gap

Claims

[1] Energy transfer device (30) comprising at least: an energy supply facility (40); a primary coil (50) electrically connected to the power supply unit; a stationary fixing element (70) comprising ferromagnetic material, wherein the primary coil (50) can be brought into an electromagnetic functional connection with the stationary fixing element (70), wherein the device comprises a rotatably mounted L-shaped profile (60) and a web (80), and that the bridge (80) and the L-shaped profile (60) comprise a ferromagnetic material, and that a rotational position of the L-shaped profile (60) can be assumed in which at least the L-shaped profile (60), the stationary fixing element (70) and the web (80) form a magnetic circle. [2] Energy transmission device (30) according to claim 1, wherein the stationary fixing element (70) is designed as an I-shaped profile. [3] Energy transmission device (30) according to claim 1 or claim 2, characterized by that the ferromagnetic material comprises a laminated metal core and / or a powder metallurgy metal core and / or a ferrite core.

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