EP3350895A1

EP3350895A1 - Energy transmission apparatus for a vehicle

Info

Publication number: EP3350895A1
Application number: EP16777630.1A
Authority: EP
Inventors: Tabea Arndt
Original assignee: Siemens AG
Current assignee: Rolls Royce Deutschland Ltd and Co KG
Priority date: 2015-10-19
Filing date: 2016-09-28
Publication date: 2018-07-25
Also published as: WO2017067761A1; CN108475907A; US20190066878A1; DE102015220301A1; CN108475907B

Abstract

The invention specifies an energy transmission apparatus for transmitting energy within a vehicle, in particular an aircraft. The transmission apparatus has a cable system which comprises at least one superconducting cable run having at least one superconducting conductor element. In this case, the superconducting cable run is designed for transmitting electrical energy with a power of at least 1 MW. The superconducting cable system has a weight, which is related to its length, of at most 2 kg/m. Furthermore, the invention proposes a vehicle comprising an energy transmission apparatus of this kind and also a method for transmitting energy using an apparatus of this kind.

Description

description

Energy transmission device for a vehicle The present invention relates to a power transmission ^¬ device for transferring energy within a vehicle, particularly an aircraft, with a Kabelsys ^¬ tem. Furthermore, the invention relates to a vehicle with such a power transmission system and a method for transmitting energy in a vehicle.

In known vehicles, normally conducting cables are typically used to supply electrical energy from a power source, such as a battery, fuel cell, or generator, within the vehicle to an electrical power source

To transfer consumers. Generally, in vehicles and particularly for aircraft, it is important here is that the Ge ^¬ weight remains as low as possible over the entire length of the energy transfer device in order to keep energy consumption for transportation of the dead weight of the vehicle low. The electrical load may be, for example, one or more elements of the on-board electrical system and / or electronics or else an electric motor for driving the vehicle, in particular a propeller motor, fan motor and / or rotor motor. Especially with an aircraft such a drive motor often has to be supplied with a high electrical power. Therefore, electrical power in the range of 1 MW and 20 MW between the at least one power source and a consumer ^¬ cher can be transferred at least must be of an appropriate power transmitting device.

A current transport services for such high to enabling ^¬ union, a normally conducting cable can be used with copper conductors according to the prior art. The meaningful

Voltage range of such cables in aircraft is due to both high-altitude ionization and by the weight rising sharply with the operating voltage the required cable insulation is limited to values below about 2.5 kV. In order to achieve a transmission power of 500 kW, for example, three-phase alternating current can be transmitted at an operating voltage of 1 kV and a total current of 500 A. A dedicated three-phase three-phase transmission device can achieve a conductor weight of approximately 3.6 kg per meter, for example when using three commercially available Nexans RHEYWIND LV-RS (N) HXCMFOE 0.6 / lkV cables. For a transmission of the electrical power required for the drive motor cable lengths of several 10 m, for example in the range of 50 m and up to 100 m, may be required in an aircraft. Such a heavy cable, to whose weight in the transmission device even the weight of the required connection devices is added, is therefore unfavorable for use in an aircraft.

Superconducting cables are generally suitable for achieving high ampacity even at low voltages with a low conductor cross section. However, conventional superconducting cables are typically also difficult since, in addition to the actual conductor elements, there are also added cryostat walls, thermal insulation elements, supporting elements and the ^¬ lectric insulation elements to the total weight. According to the state of the art, commercially available superconducting cables for such transmission devices have a double-walled cryostat whose walls are each formed as a corrugated tube. Between the two corrugated pipes lies a thermally insulating vacuum jacket and often an additional thermal insulation jacket. Such based on a high-temperature superconducting cables are commercially available ^¬ Lich example, from Nexans. Inside the inner corrugated tube, a coolant channel is arranged here, within which two or more layers of conductor strands are guided. Each layer consists ty ^¬ pisch enough, over 10 individual conductors, for example about 40 single conductor per layer. The individual layers are arranged concentrically around each other and by supporting materials As well as solid state dielectrics separated from each other to achieve the ever ^¬ specified voltage strength. Example ^¬ such as high-temperature superconducting cables for AC operating voltages of 350 kV or direct current operating voltages of 650 kV are offered. Due to the described complex structure such cables are not or not much lighter than known normal conductive cable for transmitting high electrical power. The object of the invention is therefore to provide a power transmission ^¬ device that overcomes the disadvantages mentioned. In particular, an energy transmission device is to be made available, which is particularly suitable for mobile use in vehicles. Would be a more up is to provide a vehicle with such a Energieübertra ^¬ constriction device and a method for transmission of energy.

These objects are achieved by the power transmission device described in claim 1, the vehicle described in claim 13 and the method described in claim 15.

The power transmission device of the invention for over-transmission of energy within a vehicle, especially an aircraft, comprises a cable system, which we ^¬ nigstens includes a superconducting wire harness having at least a superconducting conductor element. The superconducting cable system is designed to transmit electrical energy with a power of at least 1 MW. The supra ^¬ conductive cable system includes a related to its length Ge ^¬ weight of not more than 2 kg / m.

Below said, related to the length of the cable system weight is doing here and below, generally the Ge ^¬ samtgewicht the cable system (including any existing terminations) divided by its total length to be understood. With comparatively short cable strands affects Therefore, the weight of such terminations, which are used for example to overcome a temperature difference between cryogenic temperature and warm ambient temperature, particularly strong. Furthermore, to the said total weight of the cable system and a fluid coolant with umfas ^¬ sen, which is present to an operation of the cable system in a hold ^¬ ren coolant channel.

Thus, the transmission system according to the invention has one or more superconducting cable strands which are so light overall that they can be used in vehicles without making an excessively high contribution to the total weight of the vehicle. Through the superconducting conductor element, despite the relatively low weight, a high current carrying capacity can be achieved, whereby the transmission of services of at least 1 MW, for instance for an on ^¬ drive motor of the vehicle is possible. A core idea of the present invention is to transmit this power at comparatively high current and to utilize the high current carrying capacity of the superconducting conductor element for this purpose. The cable system then does not have to be designed for a very high voltage range, but can be set for low high voltages, for example in the range of no more than 10 kV of ^¬, so the requirements so that the weight of a wire harness can be lower to the dielectric isolation and. Thus, the complexity of the cable system compared to conventional superconducting cable systems can be reduced to achieve a low cable weight. The electrical insulation of the cable can be easily carried out, therefore, that the indicated total weight of the Ka ^¬ belsystems is not exceeded. Compared to normal ^¬ conductive cable systems can be significantly reduced by the superconducting properties of the cross section of the actual conductor element, which in turn a lower cable weight can be achieved.

The vehicle according to the invention, in particular an aircraft, has a power source, a consumer and an inventive according to the energy transfer system for transmitting electrical energy within the vehicle from the power source to the consumer. The method for transmitting power in a vehicle, especially an aircraft, comprises the steps of: generating electric power by means of the vehicle-mounted power source and over ^¬ transmission of electric current from the power source to a consumer with the aid of a power transmission device of the invention. The advantages of the vehicle according to the invention and of the method according to the invention result analogously to the stated advantages of the transfer device according to the invention.

Advantageous embodiments and further developments of the invention emerge from the claims dependent on claims 1 and 13 and the following description. The described embodiments of the power transmission device of the vehicle and the method may be advantageous way ^¬ combined.

The at least one superconducting cable strand can have a beneficial ^¬ way related to its length weight of at most 0.7 kg / m. This weight per cable harness can be particularly advantageously at most 0.3 kg / m, in particular at most 0.15 kg / m. Unlike the cable system to the said total weight that will not include here related to its length Ge ^¬ weight of a wire harness, the weight of the terminations may lie ahead with ^¬. Generally, the related to the length of the total weight of the entire cable system can (including any terminations) ^¬ advantageous way of at most 1 kg / m, particularly advantageously at Hoechsmann ^¬ least 0.5 kg / m. In this case, the cable system can also have a plurality of cable strands, for example three cable strands for the transmission of three-phase alternating current.

The cable system may generally comprise a current carrying capacity of at least 500 A, particularly advantageous ^¬ a current carrying capacity of at least 1000 A, in particular even GR At least 3000 A. In a cable system with several cable strands, in particular each individual cable harness can have such a high current carrying capacity. Such a high current carrying capacity is advantageous to a high electric power of at least 1 MW at relatively low

To transmit voltage in the range of a few kV. For example, then the cable system may be designed for operation at a voltage which is below 10 kV. For example, such an operating voltage of the cable system can be between 0.5 kV and 5 kV. The wire harness or cable strands of such a designed cable system can / can then be correspondingly easily performed because the at least one superconducting conductor element need not be protected against voltage arcing at extremely high voltages and the electrical insulation of the cable can be carried out entspre ^¬ accordingly thin and light. Thus, it can be ^¬ enough that the weight of the electrical insulation is so far below the specified total weight that the given ^¬ values for the total weight of the cable system per length are not exceeded.

The cable system may have at least one double-walled cryostat for cooling the superconducting conductor element to a temperature below its transition temperature. Between the two walls of the cryostat a vacuum can be formed to thermally insulate the interior of the cryostat against the external environment. In addition, the cryostat can have, for example, at least one further thermal insulation element between the two walls or also adjoining inside and / or outside.

Cable systems which have a plurality of cable strands may have a common cryostat within which a plurality of cable strands are routed. Thus, the weight of such a cable system with several cable strands can advantageously be kept particularly low. Alternatively, however, it is also possible in principle that each wire harness has its own surrounding cryostat. Particularly advantageously, the Kryostatwände of doppelwan ^¬ ended cryostat may be formed to a majority of the longitudinal extent of the cable system as a smooth-walled pipes. Such an embodiment is particularly advantageous in order to achieve a low weight of the cable system. For applications where high mechanical flexibility of the cable system is required, the smooth-walled double tube of such a cryostat may also be interrupted by one or more undulating sections. The correspondingly formed with a double corrugated pipe sections can be used similar to the prior art for mechanical deformation. For the low weight of the cable it is sufficient if the cryostat is formed on a part of the cable exceeds predominant length than smooth-walled cryostat from ^¬. Due to the smoothly formed in the corresponding areas Kryostatwände a rei ^¬ poor transport of a guided inside the cryostat liquid coolant is advantageously possible, which also advantageously reduces the weight of a pumping system for the cooling circuit. Also voltage flashovers between conductor element and

Cryostat wall can be advantageously reduced by a smooth shape of the cryostat wall without the need for heavy dielectric isolation elements between the conductor element and the cryostat wall.

In general, the proportion by weight of the double-walled cryostat on the weight of the cable system can advantageously be below 0.25 kg / m, in particular below 0.1 kg / m. The cryostat walls may be formed of metallic material or at least comprise a metallic material. Alterna tively the Kryostatwände ^¬ may be gebil ^¬ det also of a plastic material or comprise such a material. For example, the plastic may advantageously be a polyetheretherketone (PEEK).

The at least one superconductive conductor element may comprise a high-temperature superconducting conductor material. High- Temperature superconductors (HTS) are superconducting materials with a transition temperature above 25 K and in some classes of materials, such as cuprate superconductors, above 77 K, where the operating temperature can be achieved by cooling with cryogenic materials other than liquid helium. HTS materials are particularly attractive because these materials can have very high critical current densities, depending on the choice of operating temperature, and thus for very high cable systems

Current carrying capacities are suitable.

In particular, the high temperature superconducting material may comprise magnesium diboride. Particularly advantageously, the conductor element can comprise magnesium diboride as the main constituent or even consist essentially of magnesium diboride. Magnesium diboride has a transition temperature of about 39 K and is thus considered a high-temperature superconductor, but the transition temperature is rather low compared to other HTS materials. The advantages of this material in comparison to high-temperature oxide ceramic superconductors lie in its easy and thus inexpensive manufacturability. Magnesium diboride based conductors can be prepared particularly simply and favorably by aerosol deposition or by the so-called powder-in-tube process.

Alternatively or additionally, the conductive element may also include other high temperature superconducting materials in ^¬ play HTS materials of the second generation, that compounds of the type REBa ₂ CU30 _x (short REBCO), wherein RE represents a rare earth element or a mixture of such elements , REBCO superconductors can due to their high

Are also cooled with liquid nitrogen and have a particularly high current carrying capacity, especially at temperatures lower than 77 K.

Other advantageous materials are HTS materials of the first generation, for example the different variants of bismuth strontium calcium copper oxide. Alternatively you can superconducting pnictides are also used. Due ih ^¬ rer rather low critical temperature superconducting Pnictides eligible for an operating temperature of about 20 to 30 K in question.

The cable system can be designed for the transmission of alternating current. For this purpose, the cable system may comprise a plurality of superconducting conductor elements, which are each associated with a phase of the alternating current. In particular, it may be a cable for the transmission of three-phase alternating current. The conductor elements, which are assigned to the respective phases, can advantageously be guided in individual cable strands. For example, a single ^¬ ner harness may be provided for each phase, which may each have two electrically separate conductors. The cable strands of the individual ^¬ nen phases can, as described above, either advantageously be arranged in a common cryostat or alternatively be arranged in separate cryostat.

Alternatively, however, the cable system can also be designed as a cable system for DC transmission. Also in this embodiment can be achieved with superconducting conductor elements advantageously a transfer of high electrical power at a low overall weight of the cable system. For DC transmission, only two electrically separated superconducting conductors are advantageously required for this purpose. Accordingly, less mass per meter of cable system for insulation elements must be used, and the cable system can be made particularly easy as a DC cable system.

Generally, each harness can advantageously have only a maximum of two separate superconducting conductor elements that are ne ^¬ by side and in parallel to each other. In contrast to the state of the art - for example the cables from Nexans - here each conductor layer does not consist of a multiplicity of separate conductor strands or filaments, but each electrical conductor unit is made of only one element. formed element. In this conductor member may be, for example, a superconducting wire, a supralei ^¬ Tenden stripline or other type of superconducting layer on a substrate. It is essential that the respective conductor element not from a plurality of individual

Conductor strands is composed of or consists of a strand bundle, but only consists of a superconducting body, so that the complexity of the cable construction is significantly reduced. In this way, a much simpler and easier cable system can be realized.

As an alternative, other embodiments may also be considered advantageous in which each electrically separate conductor unit is not formed by a single, but only a few conductor elements. It can involve, for example, two to four conductor elements per electrically isolated Lei ^¬ tereinheit. In comparison with the embodiment with only one conductor element per unit of electrical conductors can be ^¬ achieved here with a higher redundancy, which still show a simple and therefore easily executed Ka ^¬ belsystem present.

Regardless of whether each cable harness has only two separate conductor elements as a single conductor or as described above, a slightly larger number of up to four conductor strands per conductor unit, the two conductor units of a Ka ^¬ belstrangs can advantageously be carried side by side and parallel to each other. In contrast to the prior art, in which the individual conductor unit typically extend coaxially into one another, such a construction can be constructed much simpler with a smaller number and / or mass of mechanical support elements and / or electrical insulation elements. Thus, such a cable harness can be formed with a lower weight per meter than a conventional cable harness with coaxially formed conductor units.

Generally, a superconducting Leiterele ^¬ ment can be carried by one or more support elements having at least and / or be surrounded by one or more electrical insulation elements. In this case, the total weight of support elements and insulating elements can in each cable strand of the cable system advantageously at most 0.1 kg / m, particularly advantageously at most 0.05 kg / m or even at Hoechsmann ^¬ least 0.03 kg / m respectively. In turn, each wire harness can in turn be assigned to one phase of an alternating current transmission system. Particularly advantageous is even the Ge ^¬ total weight for support and insulation elements in the whole cable system sels within the specified value ranges. With such a low weight for the elements of the insulation and the support, the stated maximum values for the total weight per meter for the cable harness and / or the total weight per meter for the cable system can be realized particularly easily.

The superconducting conductor member can be cooled at least during loading ^¬ operating the cable system by a fluid coolant. For this purpose, a coolant passage in the interior of the cable system, in particular be arranged in the interior of a cryostat of the cable ^¬ system in which, for example, liquid nitrogen, liquid hydrogen or liquid helium may strö ^¬ men. Advantageously, the at least one superconducting conductor element can be arranged within a coolant channel such that a liquid coolant can flow around it during operation of the energy transmission device. This is particularly advantageous since then the coolant can also serve for dielectric isolation in addition to the cooling ^¬ and thus less weight is caused by solid state dielectrics. Liquid coolant such as liquid nitrogen, liquid helium or liquid What ^¬ serstoff have a Spannungsfestig ^¬ ness in the range of 50 kV / mm. If the at least one and in particular all the superconducting conductor elements are surrounded radially on all sides by coolant, an additional solid insulation can thus either be completely eliminated or reduced to a minimum. For example, the at least one conductor element can be seen radially in all directions from at least one 1 mm to 2 mm thick liquid keitsmantel be surrounded by coolant. This liquid ^¬ coat can be substantially continuous, in which case it should not be excluded that it is interrupted by individual support elements, such as support struts, for the mechanical support tion of at least one conductor element in its interior.

The wire harness may generally have a circular outer cross section. But it may alternatively also deviates from this geometry outer cross-sectional shape aufwei ^¬ sen. For example, a lower weight of the coolant channel is ^¬ closed coolant can be achieved with a polygonal cross-section before ^¬ part adhesive, while maintaining a predetermined minimum thickness of a liquid coat the respective gene conductor elements surrounding of at ^¬ play, at least 1 mm on all sides.

Liquid hydrogen is particularly advantageous ^¬ way as the coolant because it has the liquids mentioned, a particularly low specific weight, and thus contributes little to the total weight of the respective wiring harness. Thus, even with cable diameters of several centimeters, the weight contribution of the coolant can be below 100 g / m and in ^some cases even below 50 g / m. For example, with a cable diameter of 2.5 cm, the weight contribution of the liquid hydrogen as the coolant may be about 35 g / m.

The liquid coolant may form a closed circuit via the coolant channel of the Ka ^¬ belsystems within which it reusing the refrigerant ^¬ example by means of a pump, is circulated. It can also be provided for this purpose a plurality of coolant channels within the same or inner ^¬ half different cable strands to circulate the coolant along the cable system back and forth.

Alternatively, however, the coolant can also advantageously be transported in only one direction along the cable system. This is particularly useful when the coolant is liquid hydrogen which is used at the end of the cable system to which it flows to generate energy.

As an alternative or in addition to the electrical insulation by the coolant, the at least one superconductive conductor element can be electrically insulated by a surrounding solid-state dielectric. For example, the conductor element, in particular any conductor element present, may be enveloped by an electrically insulating polymer such as, for example, extruded polyetheretherketone (PEEK). Such an envelope can be designed with a small layer thickness and thus correspondingly low weight contribution to the weight of the cable system. For example, the layer thickness can be below 2 mm, in particular below 1 mm.

The superconductive conductor element can be connected to a superconducting coil winding at at least one end of the cable system. In particular, the superconducting Leiterele ^¬ ment can be connected without any interruption of its coolable to a cryogenic temperature environment with such a superconducting coil winding. The superconducting coil winding can either also be part of the energy transmission device, or it can alternatively be an additional electrical device, which is also arranged in the vehicle. Is essential for this execution ^¬ form that the cable system does not have to be provided lock with a terminal at the end at which the superconducting ^¬ conductive coil winding is arranged, through which an electrical connection from the cryogenically cooled superconducting provided to a warm outer conductor becomes. Rather, the corresponding end of the cable is advantageously provided with a contact element for connection to the superconducting coil winding, which, like the superconducting conductor element and the superconducting coil winding, can be cooled to a cryogenic temperature. In an operation of the energy transmission device so that is at least one superconducting Conductor element, the superconducting coil winding as well as the present between ^¬ existing electrical contact throughout in a cryogenic temperature range, without intervening an electrical connection element in the temperature range of the comparatively warm ambient temperature of the vehicle is ^{¬ assigned} . This continuous cryogenic electrical connection between the conductor element of the cable system to the conductor of the coil Wick ^¬ development firstly has the advantage that the Ge ^¬ weight is saved for a costly sealing end for the connection of hot and cold conductors on this page. Thus, the

Energy transmission device are made easier overall. On the other hand, there is the additional advantage that the electrical losses are reduced by the continuous cold electrical connection. Particularly advantageously, the connection between the conductor element of the cable system and the superconducting coil winding can even be continuously superconducting. However, this is not absolutely necessary to realize the advantage of weight saving. It when the superconducting conductor element is connected at both ends of the cable system in the manner described with a superconducting coil winding and / or when all the conductor elements of the cable system are connected to one or meh ^¬ reren superconducting coil windings is particularly advantageous. In the embodiment described above, the superconducting coil winding may be a winding of a transformer or a stator or rotor winding of a motor or generator. The embodiment with a superconducting transformer winding is particularly useful when dealing with the over ^¬ tragungsvorrichtung a device for transmitting alternating current. Then, two such superconducting transformer windings can be provided - one at each end of the cable system - around the power to be transmitted after the

Transform current source to a voltage suitable for the transmission and then transform back to a voltage suitable for the consumer. At this Embodiment, the transformers are also parts of the Energieübertragungs orrichtung.

Alternatively, one end of the cable system may be connected to a winding of a motor or a generator. It is also possible that one end with a winding of a generator and the other end with a winding of a motor is connected ^¬ ver. The generator may be part of a power source arranged on the vehicle, and / or the engine may be part of a drive system arranged on the vehicle. Particularly advantageously, then the entire electrical chain between the power source, transmission system and consumer ^¬ cher continuously cold and in particular even continuously sup ^¬ raleitend be formed. This can in principle be designed for both DC and AC transmission systems. A significant advantage of such embodiments is that the weight of the transmission system can be kept low, since complex connecting elements for the connection of hot and cold conductor elements can be omitted. Furthermore, electrical and thermal losses are reduced overall. In direct current transmission systems such ^¬, through superconducting ^¬ tragungskette is particularly advantageous as there is no galvanic ^¬ specific separation by transformers and / or converter is Untitled benö-.

The energy transfer device may generally advantageously comprise a transformer at each end of the cable system to transform the current generated by a current source to a lower voltage for transmission in the cable system and to transform the transmitted current for a consumer back to a higher voltage. It is advantageous, but not mandatory, if the transformers have sup ^¬ conducting coil windings. If this is the case, there can be a continuous, cryogenic temperature-coolable environment across the windings of the two transformers and across the cable system. In particular, a cryostat of the cable system can be used continuously with the Cryostats be connected to the superconducting transformers. It can be a jointly coolable interior of these three components with a common coolant circuit vorlie ^¬ gene.

In general, transforming the alternating current to be transmitted to a lower voltage for transmission is ^{advantageous in} order to transmit the electrical energy with a cable system with a lower weight. Thus, a high voltage of some 10 kV or more can be transformed to a much lower voltage in the range below 10 kV. It then only a higher current must be transmitted, which is easy to reali ^¬ by a superconducting conductor element. On the other hand, the superconducting cable system need not be designed for very high voltages, and we ^¬ nigstens a wire harness can be carried out according to easily due to lower requirements for its dielectric strength. With superconducting transformer windings transforming can be implemented very easily to a favorable for the transmission of power without much extra weight accumulates for Transforma ^¬ tors. Advantageously, a transformer having one or more superconducting windings, namely without a soft magnetic core, can be formed in the majority of the winding, as a result of which its weight can be substantially lower than in the case of transformers with such cores. In a polyphase transformer, there may be multiple superconducting windings, with each pair of windings each associated with a phase. This Wicklun ^¬ gen can be arranged within a common cryostat, which also contributes to saving space and weight at ^¬. In general, the superconducting transformers can be advantageous as in the non-prepublished DE

102015212824 be described. In particular, the individual superconducting windings of the transformer can be designed as ring-like windings, each with an annular opening and an axial offset in the region of the opening be. A predetermined magnetic coupling of the individual phases can advantageously be achieved via these openings.

Optionally, an additional inverter may be arranged on the side of the power source and / or on the side of the load to change a frequency of the alternating current to be transmitted or transmitted. Such a converter can be arranged, for example, between the power source and the first transformer or between the second transformer and the load. Such converters can be regarded as parts of the transmission ^¬ device.

The vehicle with the described energy transmission device may be an aircraft, in particular an aircraft or a helicopter. In principle, however, it may also be another vehicle, that is to say a land vehicle, watercraft or spacecraft, in particular such a vehicle, in which the light weight of an electrical transmission device is important.

Advantageously, the aforementioned consumer of the vehicle may be an electric motor for driving the vehicle. Thus, the vehicle may be an electrically and / or hybrid-electric powered vehicle. In particular, the engine may be a

Actuator motor, fan motor and / or rotor motor of the electrically driven vehicle act.

In the following, the invention will be described by means of some preferred embodiments with reference to the appended drawings, in which:

1 shows a superconducting cable harness after a first

Embodiment of the invention in a schematic cross section shows

2 shows a superconducting cable harness after a second

Embodiment of the invention in a schematic cross section shows Figure 3 shows a superconducting cable harness to a third

Embodiment of the invention in schematic

Cross-section shows

Figure 4 shows a power transmission device according to a third embodiment of the invention and

Figure 5 shows a superconducting harness after a fourth

Embodiment of the invention in schematic

Longitudinal section shows. 1 shows a schematic cross section of a supralei ^¬ Tenden wire harness 5 is shown according to a first embodiment of the invention. Shown are two superconducting Lei ^¬ terelemente 7, each comprising only one conductor strand and are not divided into further sub-conductors. These two conductor elements 7 extend adjacent and parallel to zuei ^¬ Nander inside of the wire harness 5. They are surrounded by a double walled cryostat 9, wherein the intermediate space between the outer cryostat wall 9a and the inner cryostat wall is evacuated 9b. The vacuum V serves to thermally insulate the area within the cryostat against the warm external environment to maintain the superconducting conductor elements 7 at a cryogenic operating temperature below the critical temperature of the respective superconducting material. In order to effect the corresponding cooling efficiently, a coolant channel 13 is formed in the interior of the cryostat 9, within ^¬ half of which a fluid coolant 15 can flow. Thus, the cooling medium flows around ^¬ the two circuit elements 7 and can cool them so effective. Around the two conductor elements 7 ge ^¬ against each other and electrically insulate against the inner wall 9b of the cryostat 9, they are retained by means of support elements 11 in an inner region of the coolant passage 13 at a predetermined distance. So they have a minimum distance from each other and the inner Kryostatwand 9a, which may for example be at least 1 mm. So-acts with the gas flowing through the coolant passage 13 Kühlmit ^¬ tel 15 as a dielectric and serves for the electrical insulation of the conductor members 7 and in particular to avoid voltage flashovers. As shown in Figure 1, this electrical insulation is given only by the coolant 15 and not by another solid dielectric, then the cable harness can be performed with a particularly low cable weight per cable length. Alternatively, however, the conductor elements 7 can generally also be surrounded by additional solid-state insulation (not shown here).

It is essential for the example shown in Figure 1 that achieved by the simple configuration of the wire harness 5, a total of very low weight of the wire harness 5 who can ^¬. This cable harness 5 can be used in a cable system 3 to realize a power transmission device 1 according to the present invention, as will be described in the later example of FIG. The cable harness 5 according to the first exemplary embodiment can in particular already form the cable system 3 of the transmission device 1 as a single strand. For example, such a single cable harness can be used for DC transmission. Alternatively, a plurality of such cable strands can be used to obtain a cable system 3 therefrom. For example, multiple cable strands can be performed as parts of a sol ^¬ chen cable system parallel to each other. Thus, with three such cable strands 5 a three-phase alternating current can be transmitted.

In the following exemplary materials and dimensions are given in order to illustrate how the harness 5 shown in Figure 1 of the present invention may be embodied entspre ^¬ accordingly with a sufficiently low weight.:

The outer diameter of the cable strand 5 should be in the example shown at 2.5 cm, the distance of the inner Kryostatwand 9b and the outer Kryostat is 1 mm. The thickness of the two cryostat walls can each be about 0.2 mm. This results in cryostat walls made of stainless steel, a weight contribution of about 250 g / m and in Kryostat ^¬ walls made of PEEK a weight contribution of only about 41 g / m for both walls 9a and 9b together. This example shows clearly that the weight contribution of the Kryostatwände is signi ficantly ^¬, and that, therefore, the use of a Kunststoffma- terials is particularly advantageous. Also, the use of aluminum for the cryostat walls may be advantageous to achieve a weight reduction compared to stainless steel. For the dimensions mentioned, a weight contribution of 84 g / m results for aluminum cryostat walls.

The weight contribution of the two conductor elements results in a conductor width of 10 mm and a conductor thickness of 0.2 mm, assuming an average density of about 8 g / cm ³ to about 32 g / m for both conductor elements 7 together. The values ge ^¬ called based on typical dimensions and densities for band conductors with high temperature superconducting layers of the second generation on a metallic substrate band.

The weight contribution of the supporting elements 11 depends not only on the di ^¬ bridge and the material of the individual elements also on their axial distance, so the number per meter cable. In the example shown, the weight contribution of the support elements 11 should be below 30 g / m, that is to say lower than that of the conductor elements 7. The support elements may advantageously be formed of plastic or at least comprise plastic as a material.

The weight contribution of the coolant 15 flowing in the interior of the coolant channel 13 results in the dimensions mentioned at about 380 g / m for liquid nitrogen and at only about 34 g / m for liquid hydrogen.

Depending on the selected combination of the aforementioned examples of materials that can related to the length of the total weight of the cable ^¬ strand 5 (without a contribution of the end seals) so Zvi ^¬ rule about 137 g / m (and liquid for PEEK-Kryostatwände water serstoff) and 692 g / m are (for precious beam Kryostatwände and FLÜS ^¬ sigen nitrogen). The dimensions mentioned are of course only to be understood as examples, and the weight contributions of the individual components scale in known manner. ter manner with the diameter of the wire harness 5, the cooling ^¬ medium channel 15, the wall thickness of the Kryostatwände 9 a, 9 b and the dimensions of the conductor elements 7 and the densities of the materials used. In particular, the outer diameter of the wire harness 5 may be both higher and lower than in the example given here. It is merely to be shown here as an example, as a lightweight cable through the use of beneficial ^¬-like materials and the absence of a high volume fraction of solid dielectric sträng 5 can be realized.

2 shows a schematic cross section of a supralei ^¬ Tenden wire harness 5 is shown according to a second embodiment of the invention. Shown is a cable harness 5 for the transmission of three-phase alternating current with a total of six superconducting conductor elements 7, which are each performed in pairs next to each other. Within a pair, there is a phase conductor and a return conductor. These two conductors of a pair are supported by comparatively short support members 11 against each other, while each ^¬ the pair is supported by a total of longer supporting elements 11 against the inner wall 9b of all conductor elements 7 together ^¬ the cryostat. In the interior of the cryostat, a coolant channel 13 is formed, within which the conductor elements 7 and the support elements 11 can be surrounded by fluid coolant ^¬ medium.

3 shows a schematic cross section of an alternatively ^¬ ven superconducting wire harness 5 is shown, which is also designed for the transmission of three-phase alternating current. Here too, a total of six superconducting conductor elements 7 are arranged in ^¬ within a common cryostat 9. In this example, three conductor elements 7 acting as return conductors are arranged in the center of the inner cavity as a parallel-guided bundle, these individual return conductors being in turn supported by short support elements 11 against each other and by longer support elements 11 against the inner cryostat wall 9b. The three phase conductors 7, however, are individually in radial are further outer regions of the coolant channel 13 and are each supported individually by a plurality of support members 11 against the inner Kryostatwand 9b. With this arrangement, the overall result is a more complex network of support elements. The cross-section shown in the schematic cross-sectional representation of various support elements 11 is in reality, however, no problem, since they can be performed in the axial direction of the wire harness 5 at different positions and therefore are not really at overlapping position.

The cable strands 5 of the second and third Ausführungsbei ^¬ game can, moreover, particularly in reference to the From ^¬ states of the conductor elements 7 to each other and to the cryostat, the coolant and the optionally present additional hard ^¬ body insulation around the conductor elements analogous to the cable ^¬ strand of the be constructed first embodiment.

Figure 4 shows a schematic perspective view of an energy transmission device 1 according to a fourth

Embodiment of the invention. The energy transmission ^¬ device 1 is designed for the transmission of three-phase alternating current. It has for this purpose a cable system 3, which may comprise, for example, three cable strands according to the embodiment of Figure 1 or in accordance with the embodiment of Fi gur ^¬. 2 This cable system 3 is electric power generated by a generator 21 is transmitted to ei ^¬ nem motor 23rd Here, both Übertragungssys ^¬ tem 1 and generator 21 and motor 23 are arranged on a mobile vehicle, which is not shown here in detail. The generator 21 thus serves to generate three-phase alternating current with a generator voltage U _G and a generator current of strength I _G. For example, U _G may be about 33 kV and I _G about 30 A. These values for current and voltage can be in the same range as the values required for the motor 23 of the vehicle for current I _M and voltage UM. For transmission by means of the energy transmission device 1, however, the input current is here by means of a Transformed transformer 19 down to a lower transmission voltage U _T. After the transmission, the current is trans ^¬ formed by means of another transformer 19 again. The two transformers 19 shown here are each part of the transmission device 1. For example, the transmission voltage U _{T may be} in the range of about 1 kV and the transmission current I _T may be in the range of about 1 kA. Thus, an electric power in the range of 1 MW can be transmitted. The at least one superconducting conductor element 7 of the cable system 3 is used here in order to achieve the required high current carrying capacity for the comparatively high transmission current I _A. As the transfer voltage U _T is comparatively low, the dielektri ^¬ specific insulation of the wire harness or the cable may strands relatively easy and space-saving realized ^¬, the so that the total weight of the cable system kept for 3 (including the refrigerant contained therein 15) according to the invention low can be.

The two transformers 19 of FIG. 4 may each be constructed with superconducting transformer windings 17. In order to keep these superconducting transformer windings 17 at a cryogenic operating temperature, these coils 17 can be disposed within a cryostat designed as transformers ^¬ gate housing twentieth The total of six windings required for trans ^¬ formation of three-phase alternating current can be arranged within a common housing 20 ^¬ , as indicated in Figure 4. The further construction of the respective transformers can be described, for example, as in the unpublished DE 102015212824. Thus, the three phases and soft magnetic coupling ^¬ yoke 28 may be magnetically coupled in the end regions of the windings 17. An advantage of the superconducting embodiment of the transformers 19 in connection with the present invention is that the cryostats 20 of the transformers 19 together with the at least one cryostat 9 of the cable system 5 in FIG to form a common, continuous cold environment in their interior. As is indicated in FIG. 4, these three cryostats 20 can therefore be connected over the length 1 of the cable system 5 to form a continuous cold system. For the transitions between the superconducting conductor elements 7 of the cable system 3 to the coil windings 17 of the transformers 19 so no particular implementation in the end of the cable system 3 between cold and warm environment is necessary. The weight required in conventional cable systems for the correspondingly designed end pieces for overcoming such a temperature difference is thus saved.

In the example of FIG. 4, generator 21 and motor 23 are each connected to a further connection system 25 or 27 with the respective associated transformer 19. These other connection systems 25 and 27 are preferably made very short in comparison to the cable system 3, so that they accordingly little beitra ^¬ gen to the weight of the vehicle. Here, the stream can also be transmitted over normal conducting cable in the warm, especially when generator and motor have normal conducting windings. The transformer; ^¬ ren can then on the side facing away from the cable system in each case 3 side sen feedthroughs for connecting the cold windings 17 with the warm connection system 25 or 27 aufwei-.

As an alternative to such an embodiment, generator 21 and / or motor 23 may also have one or more superconducting stator windings. Then, the generator or the motor side of the transformers can be connected via continuous superconducting lines with the corresponding superconducting stator windings in a continuous cold environment. This saves the weight typically required for bushings between cold and warm environments and further reduces electrical and thermal losses. Figure 5 shows a schematic longitudinal section of a supra ^¬ conductive wire harness 5 according to a fifth Ausführungsbei ^¬ game of the invention. The cable cross section may be constructed as in the example of Figure 1 play as similar in ^¬. The double-walled cryostat 9 is formed into a mehrheitli ^¬ chen part of the length 1 of the harness with smooth, so unwaved Kryostatwänden 9a and 9b. In the section shown, these are the segments 33. In between, a corrugated segment 31 is arranged in the section shown. In such corrugated segments 31, the vacuum-insulated Sleeve Shirt ^¬ le on a wave-shaped profile, which increases a mechanical Flexi ^¬ stability of the line both with respect to expansion or compression than with respect to a bend in this area. In order nevertheless to achieve the lowest possible flow resistance and the lowest possible turbulence of the coolant 15 flowing in the coolant channel 13, the inside wall of the cryostat 9b may be lined internally with a smooth-walled tube insert 29 in these segments.

Claims

claims

1. Energy transmission device (1) for transmitting energy within a vehicle, in particular an aircraft,

comprising a cable system (3)

at least one superconducting cable strand (5) having at least one superconducting conductor element (7),

- Wherein the superconducting cable system (5) is designed for the transmission of electrical energy with a power of at least 1 MW

- And wherein the superconducting cable system (3) on its length (1) related weight of not more than 2 kg / m on ^¬ has.

2. Energy transmission device (1) according to claim 1, wherein a superconducting cable harness (5) has a length (1) based on its weight of not more than 0.7 kg / m and the cable system (3) has a weight based on its length of not more than 1 kg / m.

3. Energy transmission device (1) according to one of claims 1 or 2,

- In which the cable system (3) has a current carrying capacity of at least 500 A.

- And in which the cable system (3) is designed for operation at ei ^¬ ner transmission voltage (U _T ), which is below 10 kV.

4. Energy transmission device (1) according to one of the preceding claims, wherein the cable system (3) has at least one double-walled cryostat (9) for cooling the superconducting conductor element (7) whose Kryostatwände (9a, 9b) to a majority part of the longitudinal extent ( 1) of the cable system (3) are designed as smooth-walled tubes.

5. Energy transmission device (1) according to one of the preceding claims, wherein the cable system (3) for transmission supply of alternating current is formed and for this purpose a plurality of sup ^¬ raleitende conductor elements (7), which are each associated with a phase of the alternating current.

6. Energy transfer device (7) according to claim 5, in which the conductors (7) for a plurality of phases are arranged within a common double-walled cryostat (9).

7. Energy transmission device (1) according to one of the preceding claims, wherein each wire harness (5) has only two to at most six separate superconducting conductor elements (7), which are each guided in pairs next to each other and parallel to each other.

8. Energy transfer device (1) according to one of the preceding claims, in which the at least one superconducting conductor element (7) is supported by one or more support elements (11) and / or is surrounded by one or more electrical insulation elements (13),

wherein the total weight of support elements (11) and insula ^¬ onselementen (13) in each wire strand is at most 0.1 kg / m.

9. Energy transmission device (1) according to one of the preceding claims, wherein the at least one superconducting conductor element (7) is arranged within a coolant channel (13) so that it flows around during operation of the device ei ^¬ nem liquid coolant (15) can be.

10. Energy transmission device (1) according to any one of the preceding claims, wherein the superconducting conductor element (7) is connected at at least one end of the cable system (3) with a superconducting coil winding (17).

11. The power transmission device according to claim 10, wherein the superconducting coil winding is a winding of a transformer or a stator winding of a motor or a generator.

12. Energy transmission device (1) according to one of the preceding claims, which at each end of the cable system (3) comprises a transformer (19) to the power generated by a current source (21) for transmission in the cable system

(3) from an original voltage (U _G ) to a lower ^¬ re voltage (U _T ) to transform and to transform the transmitted power for a consumer (23) back to a higher voltage (U _M ).

13. Vehicle, in particular aircraft, with

a power source (21),

- a consumer (23)

- And a power transmission system (1) according to one of the preceding claims for transmitting electrical energy within the vehicle from the power source (21) to the Ver ^¬ consumer (23).

14. The vehicle of claim 12, wherein the consumer (23) is an electric motor for driving the vehicle.

15. A method of transmitting energy in a vehicle, in particular an aircraft, characterized by the following steps:

Generating electricity by means of a power source (21) arranged in the vehicle,

- Transmission of the electrical current from the power source (21) to a consumer (23) by means of a power transmission device (1) according to one of claims 1 to 12.