STATIC ELECTRIC INDUCTION DEVICE AND OPERATING METHOD

Abstract

In one example, the static electric induction device includes: a heat-generating component which is subject to electric induction, and a duct system configured to lead a coolant along the heat-generating component, wherein the duct system includes a plurality of cross channels and at least two longitudinal channels, each one of the longitudinal channels is assigned to at least some of the cross channels and the assigned cross channels connect the respective longitudinal channels with each other, and the duct system further includes at least one flow obstruction located in at least one of the longitudinal channels, the flow obstruction is configured to allow flow of the coolant through it and locally narrows a cross-section of the respective longitudinal channel by at least 75%.

Claims

1-15. (canceled)

16. A static electric induction device comprising: a heat-generating component which is subject to electric induction, and a duct system configured to lead a coolant along the heat-generating component, wherein the duct system includes a plurality of cross channels and longitudinal channels, each of the longitudinal channels having a cross-sectional area and each one of the longitudinal channels being assigned to at least some of the cross channels and the assigned cross channels connect the longitudinal channels with each other, the duct system further includes at least one flow obstruction located in at least one of the longitudinal channels, the flow obstruction is configured to allow flow of the coolant through it and locally narrows the cross-sectional area of the at least one of the longitudinal channels by at least 75% so that a bypass for the coolant is realized, the heat-generating component comprises a plurality of electric conductor sections stacked one above the other along a direction of main extent of the longitudinal channels, the cross channels in each case run between adjacent ones of the electric conductor sections, and along the direction of main extent the at least one flow obstruction is thinner than the electric conductor sections, the heat-generating component is a transformer and the electric conductor sections are transformer windings, the at least one flow obstruction comprises an obstruction plate having a plurality of bypass openings configured to be passed through by the coolant, and the at least one flow obstruction further comprises a mounting plate running in parallel with the direction of main extent, the obstruction plate and the mounting plate being manufactured from one piece of a dielectric material which is a polymeric material.

17. The static electric induction device according to claim 16, wherein the at least one flow obstruction is mechanically permanently connected with the heat-generating component, wherein the flow obstruction is free of parts which are configured to be movable in the intended use of the static electric induction device.

18. The static electric induction device according to claim 16, wherein the at least one obstruction plate is arranged in elongation with at least one of the cross channels.

19. (canceled)

20. (canceled)

21. The static electric induction device according to claim 16, wherein the at least one flow obstruction narrows the cross-section of the respective longitudinal channel by at least 85% and by at most 95%.

22. The static electric induction device according to claim 16, wherein the cross channels are oriented in a horizontal manner and the longitudinal channels are oriented in a vertical manner.

23. The static electric induction device according to claim 16, further comprising: a tank housing the heat-generating component, a pump configured to circulate the coolant through the duct system, and a cooler connected by means of the duct system wherein the tank is configured to be filled with the coolant and the duct system is configured to lead the coolant from the pump and the cooler through the tank, and the pump and the cooler are located outside the tank.

24. A method for operating the static electric induction device according to claim 16, wherein in operation the pump pumps the coolant through the cooler and the duct system so that the heat-generating component is cooled by means of a flow of the coolant, and wherein, seen along the longitudinal channels, at most 25% of a coolant flow is through the at least one flow obstruction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] A static electric induction device and an operating method described herein are explained in greater detail below by way of exemplary embodiments with reference to the drawings. Elements which are the same in the individual figures are indicated with the same reference numerals. The relationships between the elements are not shown to scale, however, but rather individual elements may be shown exaggeratedly large to assist in understanding.

[0056] In the figures:

[0057] FIG. 1 is a schematic perspective sectional view of an exemplary embodiment of a static electric induction device described herein,

[0058] FIGS. 2 and 3 are schematic sectional views of modified static electric induction devices,

[0059] FIGS. 4 and 5 are schematic sectional views of exemplary embodiments of static electric induction devices and of an operating methods described herein,

[0060] FIG. 6 is a schematic perspective view of an exemplary embodiment of a static electric induction device described herein, and

[0061] FIGS. 7 to 9 are schematic perspective views of flow obstructions for exemplary embodiments of static electric induction devices described herein.

DETAILED DESCRIPTION

[0062] FIG. 1 illustrates an exemplary embodiment of a static electric induction device 1. The static electric induction device 1 comprises a tank 2 in which a heat-generating component 2, like a power transformer, is located. As an option, the heat-generating component 4 could comprise an inner winding 44, for example, a low voltage winding, and an outer winding 45, for example, a high voltage winding. The power transformer can be of a core type as illustrated in FIG. 1, but can alternatively also be of a shell type.

[0063] Further, the device 1 comprises a duct system 5 having various ducts and optionally a pressure chamber in which the heat-generating component 4 is accommodated. The ducts connect the pressure chamber with a pump 71 and a cooler 72, and the pressure chamber is located inside the tank 2. As a further option, there can be a separate bypass 73 that allows flow of a coolant 3 outside of the pressure chamber. A flow direction F of the coolant 3 is symbolized by arrows.

[0064] FIGS. 2 and 3 illustrate cross-sectional views through the heat-generating component 4 of a modified static electric induction device 9 wherein for simplicity of the drawing only a part of one of the windings 44, 45 of FIG. 1 is schematically illustrated.

[0065] The duct system 5, compare in particular FIG. 2, comprises longitudinal channels 52 having a direction M of main extent, and further comprises a plurality of cross channels 51. The windings are stacked one above the other and may be composed of an electric conductor section 41 and of an electric insulation 42; however, an inner configuration of the windings could be much more complex than illustrated in FIG. 2. Hence, adjacent windings are distant from one another and the cross channels 51 run between adjacent conductor sections 41 and connect the assigned longitudinal channels 52 with one another. In a lateral direction, on a side remote from the heat-generating component 4, the longitudinal channels 52 are limited by duct walls 58. The duct walls 58 can be wall of the pressure chamber of FIG. 1.

[0066] For example, a height of the cross channels along the direction M of main extent is at least 1 mm and/or at most 10 mm. Alternatively or additionally, a width of the cross channels 51 perpendicular to the plane of projection of FIG. 2 is at least 2 cm and/or is at most 30 cm.

[0067] Alternatively or additionally, a thickness of the windings between adjacent cross channels 51 is at least 2 mm and/or is at most 5 cm. Alternatively or additionally, a breadth of the longitudinal channels 51 perpendicular to the direction M of main extent is at least 2 mm and/or is at most 3 cm. Optionally, in the direction perpendicular to the plane of projection of FIG. 2, the cross channels 51 and the longitudinal channels 52 can have the same width.

[0068] The conductor sections 41 can be grouped into sub-stacks 61, 62. For example, per sub-stack 61, 62 there are at least 5 and/or at most 15 of the windings and, thus, of the cross channels 51. Within a specific sub-stack 61, 62, intentionally the coolant 3 flows in the same direction, indicated by the arrows that symbolize the flow direction F. Between adjacent sub-stacks 61, 62 there is a redirection flow obstruction 54 in one of the associated longitudinal channels 52. These redirection flow obstructions 54 are impermeable for the coolant 3. Hence, by means of the redirection flow obstructions 54 all the arriving coolant is redirected, for example, by 90.

[0069] Accordingly, due to the Venturi effect at the winding next to the redirection flow obstruction 54 the flow direction can be inverted so that a circular flow around the respective winding results. However, such a circular flow leads to a decreased cooling of the respective winding so that a local hot spot H arises. This is shown only schematically in FIG. 2, and in FIG. 3 the local hot spot H is illustrated in more detail by means of the hatchings.

[0070] The strength of the Venturi effect is dependent on the flow speed of the coolant 3. For transformer oil, in order to avoid such local hot spots H, the maximum allowable speed is around 0.3 m/s, for example, in a typical configuration. Because occurrence of only one local hot spot H may lead to severe damage of the device 1, the maximum coolant speed is in particular limited to the case where no significant local hot spots H arise due to the Venturi effect.

[0071] In FIGS. 4 to 6, exemplary embodiments of the static electric induction device 1 are illustrated, wherein FIG. 6 provides a perspective view of a part of the device 1 and FIGS. 4 and 5 show sectional views of slightly different embodiments.

[0072] Compared with the modified static electric induction device 9 of FIG. 2, in the static electric induction device 1 of FIGS. 4 to 6 the redirection flow obstructions 54 are replaced by flow obstructions 53 which allow a minor fraction of the coolant 3 to pass through. For example, a cross-sectional area of the respective longitudinal channel 52 is reduced by the assigned flow obstruction 53 by at least 75% and by at most 95%. Hence, some of the coolant 3 flows through the respective flow obstructions 53.

[0073] Thus, the strength of the Venturi effect at the adjacent cross channel 51 can be reduced and an overall higher flow speed of the coolant 3 through the channels 51, 52 is enabled. For example, the flow speed can be increased by a factor between 1.5 and 3 compared with the modified static electric induction device 9 so that in the static electric induction device 1 flow speeds of the coolant 3 of up to 1 m/s may be realized. By increasing the flow speed, the cooling can be improved.

[0074] For example, the flow obstructions 53 each comprise a obstruction plate 56 in which at least one bypass opening 55 is formed. It is possible that the obstruction plates 56 are mounted onto the duct wall 58 or alternatively onto the respectively assigned winding, or onto both. Mounting could be achieved, for example, by means of a mounting plate 57 running in parallel with the direction M of main extent.

[0075] According to FIG. 4, the flow obstructions 53 and consequently the part of the obstruction plates 56 having the bypass openings 55 run in elongation with a top side of the uppermost winding of the lower sub-stack 62, seen along the direction M of main extent of the longitudinal channels 52. Contrary to that, according to FIG. 5 the flow obstructions 53 and consequently the part of the obstruction plates 56 having the bypass openings 55 run in elongation with a bottom side of the lowermost winding of the upward sub-stack 61, again seen along the direction M of main extent. It is also possible that the two variants of FIGS. 4 and 5 are both realized in the static electric induction device 1.

[0076] In FIG. 6 it is further illustrated that the flow obstructions 53 may alternatively be integrated in a coolant guiding ring 6 so that the coolant guiding ring 6 comprises at least one bypass opening 55 per associated longitudinal channel 52. As an option, a plurality of the longitudinal channels 52 can be arranged in parallel with one another all around the heat-generating component 4. Adjacent longitudinal channels 52 can be separated from one another by spacer ribs 63 which run along the direction M of main extent. Between adjacent windings, there can be conductor section spacers 64.

[0077] Concerning the configuration of the ribs 63, the spacers 64 and the channels 51, 52, reference is also made to document WO 2015/040213 A1, in particular to FIG. 1 and page 11, lines 12 to 23, as well as FIG. 4 and page 13, line 15, to page 14, line 30, the disclosure content of which is hereby included by reference.

[0078] Otherwise, the same as to FIGS. 1 to 3 may also apply to FIGS. 4 to 6, and vice versa.

[0079] In FIGS. 7 to 9, some possible examples of the flow obstructions 53 are illustrated. According to FIG. 7, the flow obstruction 53 comprises the obstruction plate 56 and the mounting plate 57. It is possible that the obstruction plate 56 is shorter than the mounting plate 57.

[0080] The plates 56, 57 could be manufactured from one piece, for example, by bending. Otherwise, the flow obstruction 53 could be produced by casting or pressing or molding. For example, the flow obstruction 53 are of a dielectric material like a polymeric material. Composites of a plurality of materials are also possible.

[0081] In FIG. 7, there is a plurality of the bypass openings 55 which may be arranged, for example, along a straight line. All the bypass openings 55 can be of the same shape. The bypass openings 55 completely run through the obstruction plate 56. There can be more than the two bypass openings 55 shown in FIG. 7, for example, there are at least three bypass openings 55 and/or at most eight bypass openings 55 per flow obstruction. In the direction perpendicular to the mounting plate 57, the bypass openings 55 can be located in a middle third of the obstruction plate 56.

[0082] In a lateral direction, in parallel with the line along which the bypass openings 55 are arranged, the mounting plate 57 and/or the obstruction plate 56 may directly adjoin the spacer ribs.

[0083] Otherwise, the same as to FIGS. 1 to 6 may also apply to FIG. 7, and vice versa.

[0084] According to FIG. 8, the bypass opening 55 is located next to the mounting plate 57, that is, in an outermost third of the obstruction plate 56 and, thus, next to the duct wall 58. Moreover, the bypass opening 55 does not need to be of circular shape as in FIG. 7, but can be of square or rectangular shape, too. Again, there can be more than one bypass opening 55 per obstruction plate 56.

[0085] Otherwise, the same as to FIG. 7 may also apply to FIG. 8, and vice versa.

[0086] According to FIG. 9, there is a plurality of the bypass openings 55, and the bypass openings 55 can have different shapes. As an option, one or some or all of the bypass openings 55 can be arranged at an edge of the obstruction plate 56, in particular next to the spacer ribs.

[0087] Otherwise, the same as to FIGS. 7 and 8 may also apply to FIG. 9, and vice versa.

[0088] The components shown in the figures follow, unless indicated otherwise, exemplarily in the specified sequence directly one on top of the other. Components which are not in contact in the figures are exemplarily spaced apart from one another. If lines are drawn parallel to one another, the corresponding surfaces may be oriented in parallel with one another. Likewise, unless indicated otherwise, the positions of the drawn components relative to one another are correctly reproduced in the figures.

[0089] The term and/or describes only an association relationship for describing associated objects and represents that three relationships may exist. For example, A and/or B may represent the following three cases: Only A exists, both A and B exist, and only B exists. Correspondingly, the wording at least one of A, B and C may represent the following seven cases: Only A exists, only B exists, only C exists, both A and B exist, both A and C exist, both B and C exist, as well as all three A and B and C exist; the same applies analogously if there are only two or more than three entities in the list following at least one of. Thus, at least one of A and B is equivalent to A and/or B.

[0090] The static electric induction device described here is not restricted by the description on the basis of the exemplary embodiments. Rather, the static electric induction device encompasses any new feature and also any combination of features, which includes in particular any combination of features in the patent claims, even if this feature or this combination itself is not explicitly specified in the patent claims or exemplary embodiments.

LIST OF REFERENCE SIGNS

[0091] 1 static electric induction device [0092] 2 tank [0093] 3 coolant [0094] 4 heat-generating component [0095] 41 electric conductor section [0096] 42 electric insulation [0097] 44 inner winding [0098] 45 outer winding [0099] 5 duct system [0100] 51 cross channel [0101] 52 longitudinal channel [0102] 53 flow obstruction [0103] 54 redirection flow obstruction [0104] 55 bypass opening [0105] 56 obstruction plate [0106] 57 mounting plate [0107] 58 duct wall [0108] 6 coolant guiding ring [0109] 61 first sub-stack [0110] 62 second sub-stack [0111] 63 spacer rib [0112] 64 conductor section spacer [0113] 71 pump [0114] 72 cooler [0115] 73 separate bypass [0116] 9 modified static electric induction device [0117] F flow direction of the coolant [0118] H local hot spot [0119] M direction of main extent of the longitudinal channels