ELECTRIC DEVICE WITH CAPSULES WITH DIFFERENTLY COOLED INTAKES

Description

[0001] The invention relates to an electrical device for connection to a high-voltage network with a vessel filled with an insulating fluid, an active part arranged in the vessel, which has a magnetizable core and partial windings for generating a magnetic field in the core, a cooling device for cooling the insulating fluid, and at least one barrier system which at least partially delimits encapsulation spaces in which at least one partial winding is arranged, wherein the barrier system guides the insulating fluid cooled by the cooling device over the encapsulation spaces in such a way that different temperatures of the insulating fluid and / or the partial windings are established in the encapsulation spaces.

[0002] Such an electrical device is already known from JP S 61 150309 A. This document discloses a winding arranged inside insulating tubes. Vertical flow channels are formed in the encapsulation space formed by the insulating tubes. JP S 52 96313 A discloses a transformer with two windings, which are also arranged in different encapsulation spaces. Further prior art can be found in JP S 54 52620 A, JP S 57 90921 A, DE 27 38 398 A1, DE 20 16 508 A1, JP S 60 246608 A, and finally US Pat. No. 6,401,518 B1.

[0003] DE 197 01 269 A1 discloses a liquid-cooled transformer. The transformer is divided into several temperature zones. A first temperature zone is described as an outer region of the winding. Another, hotter zone is located further inside. The hotter zone is defined by the transformer core, so that its heat loss is transferred to the hotter liquid in the inner temperature zone. It is proposed that the inner winding be designed for a higher insulation class.

[0004] Furthermore, transformers or chokes connected to a high-voltage network, for example, each have a container that is usually filled with a mineral insulating oil as an insulating fluid. In a transformer, a low-voltage and a high-voltage winding are arranged in the container. Both windings are inductively coupled to each other via a magnetizable core. The insulating fluid serves to insulate the windings but also to cool the transformer. For this purpose, the insulating fluid, which heats up during operation, is passed through a cooling device attached to the outside of the container to dissipate the heat. The cooling is adjusted so that a maximum temperature of the insulating fluid is not exceeded, as otherwise the solid insulation of the transformer could be damaged.

[0005] Because the aging and service life of solid insulation depend to a large extent on temperature, electrical devices have already been proposed whose windings and winding structures comprise combinations of insulating materials with different thermal performances.

[0006] In addition, alternative insulating fluids, such as ester or silicone oils, are increasingly being used in transformers, which offer higher temperature resistance. These alternative insulating fluids ensure greater fire safety and are also biodegradable. Improved environmental compatibility of insulating fluids is particularly necessary for offshore applications. Due to the improved thermal stability of these alternative insulating fluids, the transformer can be operated at higher temperatures. In this context, reference is made to the IEEE 1276(1997) standard.

[0007] In addition to the conventional insulation systems and materials currently predominantly used, so-called high-temperature insulations for electrical devices are known. However, these are cost-intensive. For this reason, so-called hybrid solutions have been proposed, which combine both high-temperature insulation and insulation made of conventional materials. For example, the barrier system features conventional insulating materials, while the conductor winding insulation is made of high-temperature materials. However, these hybrid solutions have the disadvantage that, despite the use of expensive high-temperature insulating materials, the operating temperature of the insulating fluid is significantly lower than that which would be possible with the exclusive use of high-temperature insulating materials due to the continued use of conventional insulating materials.

[0008] The object of the invention is therefore to provide an electrical device of the type mentioned above which can be operated at higher temperatures while remaining cost-effective.

[0009] The invention solves this problem by arranging insulation made of different insulating materials in the encapsulation spaces.

[0010] According to the invention, a barrier system, in conjunction with the appropriately designed cooling device, ensures that at least two partial windings can be operated in different temperature ranges, referred to here as encapsulation chamber temperatures. In other words, the barrier system ensures that the insulating fluid and the winding have different temperatures in the encapsulation chambers. The encapsulation chamber temperature, i.e., the temperature range of the partial winding and / or the insulating fluid in the respective encapsulation chamber, is expediently set such that a predetermined maximum operating temperature for this encapsulation chamber is not exceeded. This makes it possible to use different insulating materials in the encapsulation chambers.

[0011] Furthermore, the partial winding located in an enclosure where a higher enclosure temperature occurs during normal operation of the electrical device can be designed with a low insulation material. In this context, the use of twisted-core windings is possible, for example.

[0012] Enameled copper wires coated with various insulating varnishes that can withstand even high temperatures are available on the market. This also applies to a wire coated with Pyre-ML polyimide, which is thermally resistant up to 220°C. The thin layer of its varnish ensures good heat transfer from the wire to the insulating fluid.

[0013] Other partial windings, which are arranged in an encapsulation chamber in which the insulating fluid has a lower encapsulation chamber temperature, are equipped according to the invention with the usual conventional, i.e., non-high-temperature-resistant partial winding insulation or barrier systems. Thus, within the scope of the invention, the material of the barrier system can vary from encapsulation chamber to encapsulation chamber.

[0014] According to the invention, insulation made of different insulating materials is arranged in the encapsulation compartments. Insulation here refers to both the insulation of the partial winding arranged in the respective encapsulation compartment and the barrier system itself. For example, the partial windings have different conductor insulation. The first partial winding, for example, is equipped with high-temperature insulation, while a second partial winding and all subsequent partial windings have conventional insulation made of materials designed for lower temperatures. The materials of the barrier system can also vary from encapsulation compartment to encapsulation compartment.

[0015] Within the scope of the invention, the encapsulation spaces are interconnected, providing a hydraulic coupling between them. The flow of the insulating fluid is preferably driven by a pump (OD cooling).

[0016] According to the invention, the barrier system guides the insulating fluid through the encapsulation chambers one after the other, or in other words, sequentially. The cooled and thus cold insulating fluid initially flows into the first encapsulation chamber and ensures the cooling of the partial winding arranged there. The insulating fluid heats up and thus enters the second encapsulation chamber, which follows in the direction of flow. If more than two encapsulation chambers are provided, the insulating fluid flows from the second to the third encapsulation chamber, and so on. In each encapsulation chamber, the insulating fluid heats up slightly, causing the encapsulation chamber temperature to rise. The insulating fluid therefore has the highest encapsulation chamber temperature in the last encapsulation chamber.

[0017] According to this variant of the invention, each encapsulation chamber is connected to another encapsulation chamber, forming a series of encapsulation chambers arranged one after the other in the flow direction of the insulating fluid, with the first encapsulation chamber of said series forming an inlet opening and the last encapsulation chamber of said series forming an outlet opening. The encapsulation chambers thus form a hydraulic series connection. The insulating fluid enters the series-connected encapsulation chambers through the inlet opening and exits them again through the outlet opening. The opening between two encapsulation chambers is referred to here as a connecting opening. A meandering channel system formed by a labyrinth-like barrier system can be arranged downstream of the inlet opening and each connecting opening. The barrier system advantageously also forms a labyrinth structure in the region of the inlet and / or connecting opening.

[0018] According to the invention, the barrier system encloses a partial winding at least in sections. The barrier system is, for example, partially hollow-cylindrical, and this part is arranged concentrically with at least one partial winding.

[0019] The barrier system consists, for example, partly of pressboard, paper, or other cellulose. According to this variant of the invention, the barrier system serves as both a thermal and an electrical barrier.

[0020] In a preferred embodiment of the invention, an electrically required section of the barrier system is incorporated into the formation of the encapsulation spaces as an encapsulation or insulation section. Therefore, essential components of the encapsulation are formed by the appropriate design of the cylindrical, disc-shaped, and curved sections of the electrical barriers. For this purpose, the conventional meandering horizontal barriers are closed off to the outside, so that the inflow and outflow of the insulating fluid to the encapsulation spaces can only occur via defined inlet and outlet openings. Furthermore, in this embodiment, the encapsulation spaces are fluidically connected to one another by using the gap between the cylindrical sections of the barriers forming the encapsulation as a return flow channel for the insulating fluid.In this design, the flow of the insulating fluid is redirected and guided by the appropriate design and connection of the curved sections of the barriers to the adjacent cylindrical and disc-shaped sections of the barrier system. In areas and transitions where the number and design of the electrically required barriers do not allow for the flow of the insulating fluid to be redirected and guided, additional curved, cylindrical, or disc-shaped barrier sections are inserted to guide the flow and seal the flow channel.

[0021] Advantageously, the gaps between the barriers of the encapsulation spaces, which form part of the electrical barrier arrangement and which in this embodiment are used as flow channels for the diversion and return of the insulating liquid, are at least partially divided into narrower partial gaps by further electrical barriers located within the flow channels in order to increase the electrical strength.

[0022] According to the invention, the partial winding with the greater high-voltage stress, i.e. with the higher proportion of insulating material, is now arranged in the area which is upstream in terms of flow technology, i.e. the area with the colder insulating fluid.

[0023] According to the invention, the first partial winding is a low-voltage winding, and a second partial winding is a high-voltage winding. The two windings are arranged concentrically to one another and, for example, also to a core section extending through the inner low-voltage winding. In other words, the electrical device according to this embodiment of the invention is a transformer with concentric high-voltage and low-voltage windings as partial windings. The partial windings are advantageously designed as circumferentially closed cylindrical windings.

[0024] As already described above, it is advantageous within the scope of the invention for the cooling device to have a supply line that forms an outlet opening arranged, for example, below the first partial winding and in particular below the high-voltage winding. According to this variant, the cooled insulating fluid is guided from the cooling device via the supply line directly into the encapsulation space of the first partial winding, so that the first partial winding is cooled more effectively than the other partial windings arranged downstream of the first partial winding in the direction of flow of the insulating fluid.

[0025] According to a further variant, the partial windings are designed for different operating voltages, wherein the temperature of the insulating fluid and / or the partial winding in the encapsulation space in which a partial winding designed for a higher voltage is arranged is lower during normal operation of the electrical device according to the invention than the temperature of the insulating fluid and / or the partial winding in the encapsulation space in which a partial winding designed for a comparatively lower voltage is arranged. The partial winding designed for higher voltages has a larger proportion of insulating material than the partial winding for lower voltages. In order to avoid expensive high-temperature insulating materials there, the cooled insulating fluid is first fed to the partial winding across which a higher voltage drop, for example in the range of several hundred kilovolts, occurs during normal operation.

[0026] Advantageously, the cooling device has a control unit with temperature sensors. The control unit has a threshold value for each temperature range and controls the cooling capacity of the cooling device depending on the respective threshold value. The respective threshold value is determined, for example, depending on the respective class of insulating material of the partial windings. If the temperature detected by the temperature sensors reaches the threshold value, the control unit controls, for example, a circulation pump of the cooling device, thus increasing its cooling capacity. Each temperature range of a partial winding is advantageously equipped with a sensor.

[0027] According to a further development useful in this regard, the temperature sensors are configured to detect the temperature of a partial winding and / or to detect the temperature of the insulating fluid in a partial winding.

[0028] In a further variant, the barrier system has at least one insulation section which is designed to control electrical field strengths.

[0029] According to a further variant, the barrier system defines parallel vertical flow channels with opposite flow directions, with at least one of the vertical flow channels being arranged as a return channel between insulation sections surrounding a respective partial winding. In this variant, the cooled insulating fluid flows, for example, from bottom to top through the first vertical flow channel. Its flow is thus aligned with the inherent movement of the insulating fluid caused by heating.

[0030] Of course, it is possible within the scope of the invention to provide several parallel flow channels. These can be horizontal or vertical channels. During operation, the insulating fluid can flow through adjacent flow channels in the same direction. The flow channels can be delimited by the insulation sections, or in other words, by sections of the barrier system that serve to electrically insulate the partial windings. The design of the flow channels is possible in a variety of ways within the scope of the invention.

[0031] Advantageously, channels between the barriers which are not required for the targeted fluid flow are closed by shims to avoid bypass formation.

[0032] In a preferred embodiment of the invention, the main flow of the insulating fluid within the encapsulation chambers is from bottom to top, thus paralleling the inherent thermal motion of the insulating fluid. Outside the encapsulation chambers, the insulating fluid is diverted to another insulation section. In these areas without a heat source, the flow is from top to bottom, before flowing into another encapsulation chamber, again identical to the inherent thermal motion of the insulating fluid, from bottom to top.

[0033] Advantageously, a wall of the barrier system between parallel vertical flow channels with opposite flow directions is thermally insulated. Thermal insulation can be achieved, for example, by a wall thickness greater than that of the remaining components of the barrier system or by a thermal coating.

[0034] Advantageously, at least one partial winding forms temperature ranges in which insulating materials with varying thermal load capacities are arranged. The insulating materials are, for example, each assigned to different thermal classes.

[0035] According to one variant, each temperature zone equipped with different insulating materials is equipped with a thermal sensor for measuring the hot-spot temperature of the respective temperature zone. The sensors are connected to a control unit that monitors the hot-spot temperature separately for each temperature zone. For this purpose, each temperature zone is assigned threshold values ​​tailored to the respective insulating materials used.

[0036] In a further variant of the invention, the barrier system is designed such that cooling channels of the magnetic core are included in the forced flow of the insulating fluid.

[0037] In a variant of the invention, the temperature classes for the insulating components are also graded according to their thermal stress within a temperature range of a partial winding. Thus, for example, the conductor insulation is designed according to the hotspot temperature of the respective temperature range. Insulating components within the respective temperature range, but which maintain a certain distance from the hottest spots of the respective partial winding, can be designed in a lower thermal class if the corresponding temperature gradient permits.

[0038] Thus, gradations of thermal strength can be provided, for example, in the following order: 1. Conductor insulation 2. Spacers with contact to the conductor (riders, shims, strips) 3. Potential control rings and barriers (cylindrical barriers, angle rings, caps, strips between the barriers)

[0039] Preferably, winding parts that require complex insulation technology, in particular winding leads, are arranged in the area where the insulating liquid enters the corresponding winding section.

[0040] Partial windings which, due to their geometry or technical design, are not suitable for integration into the described fluidic series circuit can still form separate concentrically arranged winding blocks.

[0041] According to the invention, operation at higher temperatures is possible, eliminating the need for costly conversion of, for example, the insulating material-rich winding components of a high-voltage winding to high-temperature insulating materials. Furthermore, a higher current density in the winding conductors and thus a significant reduction in size are possible. Within the scope of the invention, increasing the temperature of the insulating fluid leads to a significant increase in the temperature difference to the external cooling medium, such as air or water. This significantly increases the cooling effectiveness, allowing the electrical device according to the invention to be designed more compactly.

[0042] The high viscosity of ester- and silicone-based insulating fluids further offers flow and cooling advantages when operating at higher temperatures. This allows for optimized losses under normal load conditions while providing a high overload margin. For certain applications, the wide temperature range of the insulating fluid enables the effective use of external evaporative coolers and heat pipe-based coolers.

[0043] Further expedient embodiments and advantages of the invention are the subject of the following description of embodiments of the invention with reference to the figure of the drawing, wherein the Figures 1 to 4 illustrate embodiments of the electrical device according to the invention schematically in a side view.

[0044] The Figure 1The drawing shows an embodiment of the electrical device 1 according to the invention, which is designed as a transformer. The transformer 1 has an active part 2, which is formed from a core 3, a low-voltage winding 4 and a high-voltage winding 5. The low-voltage winding 4 and the high-voltage winding 5 are arranged concentrically to a leg 6 of the core 3, wherein Figure 1 only one side of the windings is shown. However, it should be noted that both the low-voltage winding and the high-voltage winding are circumferentially closed partial windings, i.e., they run in a ring-like manner around leg 6.

[0045] The active part 2 is arranged within a vessel 7 filled with an insulating fluid 8, in the illustrated embodiment a vegetable ester. A cooling device 9 is attached to the vessel 7 and features a cooling register 10, a circulation pump 11, a supply line 12, and a return line 13. The transformer 1 is designed for connection to a high-voltage network, so that during operation of the transformer, the high-voltage winding 5 is at a high-voltage potential, i.e., is subjected to a voltage of over 50 kV. A barrier system 14, which almost completely encloses both the low-voltage winding 4 and the high-voltage winding 5 with one of its insulating sections, serves to control the resulting electric field.The barrier system 14 is at least partially made of pressboard or another cellulose-based material and has curved sections 15 and cylindrical sections 16, which are arranged relative to one another such that the high-voltage winding 5 and the low-voltage winding 4 are each arranged in an encapsulation space 17 and 18, which are fluidically connected to one another. The encapsulation spaces 17, 18 are not completely fluid-tight. Therefore, some insulating fluid 8 can also escape from the inside to the outside of the barrier system 14 above the high-voltage winding 5. However, these "unintentionally" escaping fluid quantities can be neglected with regard to cooling. The majority of the insulating fluid flow is guided through the barrier system 14.The barrier system 14 forms an inlet opening 19 below the high-voltage winding 5, through which the cooled insulating fluid emerging from the supply line 12 of the cooling device 9 enters the barrier system 14. Furthermore, the barrier system 14 also forms an outlet opening 21, which in the example shown is located above the low-voltage winding 4. The encapsulation spaces 17 and 18 are also hydraulically coupled to each other.

[0046] The circulation pump 11 ensures that the insulating fluid 8 flows through the active part 2 and the vessel 7 in the direction indicated by flow arrows 23. Each partial winding 4 and 5 has shield rings 24 arranged at its upper and lower ends for field control.

[0047] By circulation by means of the circulation pump 11, the insulating fluid 8, i.e. the ester, is guided via the cooling register 10 and cooled, whereby the cooled insulating fluid 8 emerging from the outlet opening 20 of the supply line 12 enters the barrier system 14 through the inlet opening 19. There, the insulating fluid 8 is deflected several times, i.e. guided in a meandering manner, until it reaches the lower end of the high-voltage winding 5, in which cooling channels are formed. In these cooling channels (not shown in the figure), the heat loss of the high-voltage winding 5 is transferred to the insulating fluid 8 flowing through the cooling channels. This results in a continuous heating of the insulating fluid 8. The high-voltage winding 5 forms two temperature regions 25.1 and 25.2, which are Figure 1are indicated by a different pattern. In these temperature ranges 25.1 and 25.2, winding 5 is equipped with different insulating materials, which are assigned, for example, to different thermal classes.

[0048] The gradually warming insulating fluid 8 flows from the encapsulation chamber 17 of the high-voltage winding 5 into the encapsulation chamber 18 of the low-voltage winding 4. The barrier system 14 then guides the insulating fluid 8 over the low-voltage winding 4, which also has cooling channels and temperature zones 25.3 and 25.4 with different insulating materials. Finally, the insulating fluid 8, heated once again here, flows through the outlet opening 21 into the vessel interior. From there, the insulating fluid 8 is fed back to the cooling register 10 via the return line 13 and the circulation pump 11. The cooling cycle begins again.

[0049] Since the insulating fluid 8 is successively passed through the encapsulation chambers 17 and 18, different encapsulation chamber temperature ranges develop in the temperature ranges 25.1, 25.2, 25.3, and 25.4. Thus, the encapsulation chamber temperature, i.e., the temperature of the winding 5 and the insulating fluid 8, is on average lower in temperature range 25.1 than in temperature range 25.2 and especially than in temperature ranges 25.3 and 25.4.

[0050] By arranging insulating materials with different heat resistance in the appropriate temperature ranges of the partial windings, unnecessary costs are avoided.

[0051] The following provides an example assignment of thermal classes to the winding areas 25.1 - 25.4 shown in the exemplary embodiment. In the exemplary embodiment, an ester oil is used as the insulating fluid.

[0052] Design example of partial windings 4.5 according to Fig. 1(Thermal classes of insulating materials according to EN 60085:2008) Temperature range 25.1 25.2 25.3 25.4 Conductor insulation E (120°C) B (130°C) F (155°C) H (180°C) spacers A (105°C) E (120°C) B (130°C) F (155°C) Barrier system / potential control rings A (105°C) A (105°C) E (120°C) B (130°C) Spacers include: Radial and axial spacers (strips, riders, intermediate layers) Barrier system includes: Barriers, angle rings, caps, discs, insulating cylinders

[0053] The grading of the thermal performance of the insulating materials can also be carried out within the thermal classes according to EN 60085; there are a variety of options here, for example, grading in temperature steps of less than 10 Kelvin is also possible.

[0054] Fig. 2shows a simplified embodiment of the electrical device 1 according to the invention, with the barrier system 14 being particularly clearly visible. The barrier system 14 is designed such that it can be used to guide and redirect the flow of the insulating fluid 8. For this purpose, the barrier system 14 again has cylindrical sections 16, 16.1, 16.2, 16.3, disc-shaped sections 26.1, 26.2, 26.3, and curved sections 15, 15.1, 15.2, 15.3, and 15.4, the latter also being referred to as angle rings or caps.

[0055] According to the invention, the barrier system 14 is designed such that encapsulated winding spaces are formed, which are referred to here as encapsulation spaces 17, 28. For this purpose, the usually present, outer horizontal, disc-shaped barriers defining a flow channel for the insulating fluid are replaced by closed discs 26.2, 26.3, so that the inflow and outflow of the insulating fluid 8 into the encapsulation spaces 17 and 18 takes place in a controlled manner via the inlet opening 19 and outlet opening 21. The encapsulation spaces 17 and 18 are fluidically connected to one another by using the gap between the cylindrical sections 16.2 and 16.3 as a return flow channel 27 for the insulating fluid. In the exemplary embodiment, the inlet opening 19 is formed in the so-called winding substructure.

[0056] The outlet opening 21 is located in the disc-shaped section 26.1. In the illustrated embodiment, the gap between the curved sections 15.3 and 15.4 is used to deflect, or in other words, reverse the direction of, the flow 23 of the insulating fluid 8.

[0057] For high-voltage applications, the construction of closed barrier surfaces as perpendicular to the field direction as possible is preferable. Accordingly, the curved barriers should also advantageously follow the course of the equipotential lines. The resulting largely parallel arrangement of the curved sections 15, 15.2 also facilitates their use as flow channels 27 for redirecting the flow of the insulating fluid 8, so that only minor fluidic modifications are necessary. At transitions where the number of electrically required curved barrier sections 15.4, 15.5 does not allow reversal of the flow of the insulating fluid, additional curved barriers 15.3 are inserted to guide the flow and seal the winding space from the outside.

[0058] In the illustrated embodiment, an additional curved barrier 15.3, which serves to redirect the flow of the insulating fluid, creates an overlap of several solid insulation layers at the interface between the cylindrical and curved barrier sections. To avoid unfavorable field conditions caused by an excessive overall thickness of the solid insulation forming the electrical barrier, collared 15.2 and uncollared angle rings with a small wall thickness 15.3 are combined at the interface between the curved barriers and the cylindrical barriers and arranged opposite one another on the cylindrical section 16.3.

[0059] Fig. 3shows an embodiment in which only one of the encapsulation chambers 17, 18 has a partial winding with multiple temperature ranges 25.1 and 25.2. The thermal class of the conductor insulation 26 increases from encapsulation chamber 17 to encapsulation chamber 18, and in the latter, again from temperature range 25.1 to temperature range 25.2. The transition between the temperature ranges occurs after reaching a winding height H1.

[0060] To increase the electrical strength, the oil gaps of the insulation structure are divided, as is known, by the barrier system 14 into narrower vertical channels 27 and horizontal channels 28. These channels 27, 28 are used according to the invention to conduct the insulating fluid 8 to the partial winding 4 downstream in the flow direction 23. In the exemplary embodiment, several of these channels 27, 28 extend parallel to one another in order to achieve the cross-section required for the flow of the insulating fluid 8. The cross-section, or more precisely the cross-sectional area, and the number of interconnected vertical 27 and horizontal 28 channels can differ from one another within the scope of the invention. To avoid bypasses, the channels 29 that are not used as flow channels are completely or partially closed at their lower end by shims 30 made of insulating material.

[0061] In the illustrated embodiment, traditional disc windings are depicted within the temperature ranges 25.1 and 25.2. The insulating fluid 8 flows from an outer vertical channel through several horizontal channels into a second outer channel, where the flow direction of the insulating fluid 8 is redirected, so that the insulating fluid 8 flows in the opposite direction further along the winding height, changing flow direction several times along the winding height. However, the inventive design of the barrier system 14 and insulation is analogously applicable to all other winding types.

[0062] In the illustrated embodiment, the partial windings are equipped with thermal sensors 31 at the so-called hot spots of their respective temperature ranges 5, 25.1, and 25.2. The sensors 31 are connected to a control unit not shown in the figure.

[0063] At the outlet opening 21 of the last thermally series-connected partial winding 4, a further sensor 32 is arranged for measuring the maximum temperature of the insulating fluid 8. If necessary, the maximum temperature of the insulating fluid 8 in the upstream partial winding 5 can also be monitored via sensor 33.

[0064] Fig. 4 shows an embodiment in which the core 3 is incorporated into the cooling circuit. This is advantageous when a large temperature spread of the insulating fluid 8 is intended. The design of the core 3 for higher temperatures requires only a very small effort, since no molded parts are required and an electric field stress does not have to be taken into account. Therefore, the core 3 is arranged at the end of the fluidic series connection of the components of the electrical device 1 to be cooled. In the embodiment according to Figure 4The insulating fluid 8 flows through the windings 5 ​​and 4 one after the other, followed by the core 3. The cooling channels of the partial windings 4, 5 and the cooling channels 34 of the core 3 are connected in series thermally and fluidically. In the exemplary embodiment, the barriers are designed such that the main flow of the insulating fluid 8 within the encapsulation spaces 17 and 18 and in the core 3 is directed from bottom to top, i.e., is aligned with the inherent movement of the insulating fluid 8 generated by heating. The insulating fluid 8 is returned in the vertical channels 27 between the barriers of the insulation arrangement, which are referred to here as insulation sections of the barrier system 14.

[0065] In the exemplary embodiment, the vertical sections 16 of the barrier system 14, which define channels 27 with opposing flow directions, are provided with additional thermal insulation 35 in areas with a high temperature difference of the insulating fluid 8. This can be achieved in a simple case by increasing the wall thickness. In the areas close to the direction reversal of the insulating fluid 8, the temperature difference is small. Therefore, no measures are required there.

Claims

1. Electrical device (1) for connecting to a high-voltage network, with - a vessel (7), which is filled with an insulating fluid (8), - an active part (2), which is arranged in the vessel (7) and has a magnetizable core (3) and partial windings (4, 5) for generating a magnetic field in the core (3), - a cooling device (9) for cooling the insulating fluid (8), and at least one barrier system (14), which at least partially delimits encapsulating spaces (17, 18), in which at least one partial winding (4, 5) is respectively arranged, the barrier system (14) guiding the insulating fluid (8) cooled by the cooling device (9) across the encapsulating spaces (17, 18) in such a way that different temperatures of the insulating fluid and / or the partial windings (4, 5) occur in the encapsulating spaces (17, 18), wherein insulations of different insulating materials are arranged in the encapsulating spaces (17, 18), wherein the barrier system (14) guides the insulating fluid (8) through the encapsulating spaces one after the other, and wherein the first partial winding is a low-voltage winding (4) and a second partial winding is a high-voltage winding (5), the windings (4, 5) being arranged concentrically in relation to one another and in relation to a core portion (6) extending through the inner low-voltage winding, the barrier system having at least one hollow-cylindrical part (16, 16.1, 16.2, 16.3) which is arranged concentrically in relation to the partial winding (4, 5) surrounded by it.

2. Electrical device (1) according to Claim 1, wherein each encapsulating space (17) is connected to a further encapsulating space (18), with the result that a series of encapsulating spaces (17, 18) arranged one behind the other in the direction of flow of the insulating fluid (8) is formed, the first encapsulating space (18) of said series forming an inlet opening (19) and the last encapsulating space of said series forming an outlet opening (21).

3. Electrical device (1) according to either of the preceding claims, wherein the partial windings (4, 5) are designed for different operating voltages, the temperature of the insulating fluid (8) and / or of the partial winding (4, 5) in the encapsulating space (17) in which a partial winding (5) designed for higher voltage is arranged being lower during normal operation than the temperature of the insulating fluid (8) and / or of the partial winding in the encapsulating space (18) in which a partial winding (4) designed for a comparatively lower voltage is arranged.

4. Electrical device (1) according to Claim 3, wherein the barrier system (14) forms core connecting ducts, which extend from an encapsulating space (18) arranged last in the direction of flow of the insulating fluid (8), and cooling ducts (34) of the core (6).

5. Electrical device (1) according to one of the preceding claims, wherein the cooling device (9) has a control unit with temperature sensors (31, 32, 33), the control unit having a threshold value for each encapsulating space (17, 18) or each temperature region (25.1-25.4) of one of the partial windings (4, 5) and controlling the cooling output of the cooling device (9) in dependence on the respective threshold value.

6. Electrical device (1) according to Claim 5, wherein the temperature sensors (31, 32, 33) are designed for sensing the temperature of a partial winding (4, 5) and / or for sensing the temperature of the insulating fluid (8) in a partial winding (4, 5) .

7. Electrical device (1) according to one of the preceding claims, wherein the barrier system (14) has at least one insulating portion that is designed for reducing electrical field strengths.

8. Electrical device (1) according to Claim 7, wherein the barrier system (14) delimits vertical flow ducts (27) running parallel to one another with opposite directions of flow, at least one of the vertical flow ducts (27) being arranged as a return duct between insulating portions respectively surrounding a partial winding (4, 5).

9. Electrical device (1) according to Claim 8, wherein a wall of the barrier system (14) between vertical flow ducts (27) running parallel to one another with opposite directions of flow has a thermal insulation (35).

10. Electrical device (1) according to one of the preceding claims, wherein at least one partial winding (4, 5) forms temperature regions (25.1, 25.2, 25.3, 25.4) in which insulating materials that have differing degrees of thermal loadability are arranged.

11. Electrical device (1) according to Claim 10, wherein at least two temperature regions (25.1, 25.2, 25.3, 25.4) are respectively provided with a thermal sensor (31) for measuring the hotspot temperature of the winding in the respective temperature region.

12. Electrical device (1) according to one of the preceding claims, wherein the barrier system (14) forms flow ducts (27, 28) running parallel to one another at least in certain portions.