On-load tap changer and tap-changing transformer having an on-load tap changer

Abstract

The invention relates to an on-load tap changer (1) for uninterrupted load transfer between different winding taps of a tap-changing transformer (30), comprising - a load diverter (43) and a selector (50); wherein - the selector (50) has a contact support (60) with a number of fixed contacts (61); - the selector (50) has a planetary gearing (59) with a first ring gear (53), a first planet gear (52) and a first sun gear (51); and - the first ring gear (53) has a first selector contact (71) for contacting the fixed contacts (61).

Description

[0001] On-load tap-changer and tap-changer with on-load tap-changer

[0002] The invention relates to an on-load tap changer for uninterrupted load switching between different winding taps of a tapped transformer.

[0003] Furthermore, the invention relates to a tap-changer with an on-load tap-changer for uninterrupted load switching between different winding taps of the tap-changer.

[0004] On-load tap-changers are known from the prior art and typically comprise a diverter switch and a selector. The diverter switch, with its vacuum interrupters and switching resistors, is housed in a cylindrical container. The selector is constructed from a plurality of bars arranged in a circle. Contacts are arranged at different levels on these bars, serving as connections for the taps of a regulating winding. Within the selector, two selector arms are attached to a switch column. These arms contact the contacts on the bars. The selector arms are operated via a complex Geneva gear mechanism located between the diverter switch and the selector.

[0005] The object of the invention is to create an on-load tap-changer which is simple and compact in design and offers a high level of safety.

[0006] This object is achieved with an on-load tap-changer according to claim 1. The features of the subclaims constitute advantageous developments of the invention.

[0007] A further object of the invention is to provide a tap-changer with an on-load tap-changer which is simple and compact in design.

[0008] This object is achieved with a step-down transformer according to claim 1 1. The features of the subclaims constitute advantageous developments of the invention.

[0009] According to a first aspect, the invention proposes an on-load tap changer for uninterrupted load switching between different winding taps of a tapped transformer, comprising a load changer and a selector; wherein the selector has a contact carrier with a plurality of fixed contacts; the selector has a planetary gear with a first ring gear, a first planet gear, and a first sun gear; the first ring gear has a first selector contact for contacting the fixed contacts.

[0010] The use of a planetary gear in the selector of an on-load tap-changer enables a particularly space-saving design. The planetary gear, which consists of a sun gear, a planetary gear, and a ring gear, is particularly smooth-running, robust, and can withstand particularly high torque loads. Because the ring gear not only transmits the motion, thus forming part of the planetary gear, but also includes the selector contact, a separate selector arm is unnecessary. This also leads to a significant reduction in the size of the selector and thus of the entire on-load tap-changer.

[0011] The selector can be configured in any desired manner; in particular, the selector and the planetary gear can comprise a first and a second ring gear, a first and a second planet gear, and a first and a second sun gear. A first selector contact is arranged on the first ring gear, and a second selector contact is arranged on the second ring gear.

[0012] The selector contacts can be screwed, glued, clipped, or molded onto the ring gear. The ring gears thus not only form part of the planetary gear system and transmit the rotary motion, but also serve as the selector arms of the selector.

[0013] Each ring gear can be configured in any desired manner; in particular, the first ring gear and / or the second ring gear can have a first and a second end-position lock; the first and / or the second ring gear can have internal toothing, and the first and second end-position locks can be designed as wall elements at a respective end of the toothing.

[0014] The limit stop devices can be designed as wall elements or blocks. These can be part of the ring gears, or they can be screwed, clamped, or clipped onto the ring gear. The limit stop devices are located at the end of the internal gearing, particularly in the area where the planetary gear engages to transmit the rotational movement of the sun gear.

[0015] Each sun gear can be designed in any desired manner, for example, the first and second sun gears can each have partial teeth.

[0016] The partial toothing of the two sun gears enables the continuous rotation of the drive shaft to be converted into a step-by-step movement of the sun gears and thus of the selector arms, i.e., the ring gears. The offset of the partial toothing of the two sun gears results in a staggered operation of the ring gears. The partial toothing of the first sun gear is offset from the partial toothing of the second sun gear.

[0017] Each sun gear can be designed in any desired manner, for example the first and second sun gears can be arranged one above the other on a drive shaft.

[0018] The first sun gear, the first planet gear and the first ring gear are formed or arranged in a mirror image by the second sun gear, the second planet gear and the second ring gear on the drive shaft.

[0019] Furthermore, one or more permanent main contacts can be arranged on the drive shaft between the selector and the diverter switch. These can be designed as simple contacts or sliding contacts.

[0020] The load transfer switch can be designed in any way and can, for example, have semiconductor switching elements.

[0021] The contact carrier can be designed in any desired manner, for example, tubular and as a separate part of a flange module. The contact carrier is designed as an injection-molded part and is connected to the flange module by form-fitting or frictional engagement. The flange module is then designed in several parts.

[0022] The contact carrier can be designed in any desired manner and, for example, form a unit with the flange module. The contact carrier is formed in a section of the flange module.

[0023] According to a second aspect, the invention proposes a tap-changer with an on-load tap-changer, comprising:

[0024] - a housing; an active part with winding taps; where

[0025] - the on-load tap-changer is arranged above and / or next to the active part; the selector is electrically connected to the winding taps of the active part via its fixed contacts.

[0026] The tap-changer with the on-load tap-changer is particularly compact and safe.

[0027] The tap-changer can be designed in any way, with the on-load tap-changer being aligned horizontally or vertically inside the tap-changer.

[0028] The invention and its advantages are described in more detail below with reference to the accompanying drawings. They show:

[0029] Fig. 1 shows an on-load tap changer in a tapped transformer;

[0030] Fig. 2 is a sectional view of the on-load tap-changer;

[0031] Fig. 3 is a detailed sectional view of a selector;

[0032] Fig. 4 a detailed view of a planetary gear;

[0033] Fig. 5 another detailed view of the selector.

[0034] Figure 1 shows an on-load tap-changer 1 for uninterrupted load switching between different winding taps 31 of a tapped transformer 30. The on-load tap-changer 1 is mounted horizontally above the active part 32 of the tapped transformer

[0035] 30 and protrudes laterally from the housing 6 of the tap-changer 30. Alternatively, the on-load tap-changer 1 can be arranged vertically, in which case it protrudes from the top of the housing 6 or the cover 7. The on-load tap-changer 1 is connected via cables to the respective winding taps 31 of the active part 32.

[0036] The tapped transformer 30 is a single- or multi-phase distribution transformer, which can be designed, in particular, as a so-called mast-mounted transformer, service transformer, pad-mounted transformer, or pole-mounted transformer. This tapped transformer is preferably used for voltages up to 36 kV.

[0037] Figure 2 shows a detailed sectional view of the on-load tap-changer 1 for uninterrupted load switching between different winding taps

[0038] 31 of a tap-changer transformer 30. The on-load tap-changer 1 has a flange module 2, which is essentially divided into two sections. The first section 10 is separated from the second section 20 by a wall 4. After the on-load tap-changer 1 is installed, the first section 10 of the on-load tap-changer 1 is located outside the tap-changer transformer 30. The second section 20 of the on-load tap-changer 1 is located inside the tap-changer transformer 30.

[0039] When assembling the on-load tap-changer 1, the flange module 2 of the on-load tap-changer 1 is inserted through an opening 3 of the housing 6, here a wall 4 of the tap-changer 30. This is possible because the flange module 2 and thus the on-load tap-changer 1 in the first area 10 have a smaller or approximately equal diameter than the diameter of the opening 3 in the wall 4 of the tap-changer 30.

[0040] The flange module 2 has a flange 5 whose diameter is larger than the diameter of the opening 3. The flange module 2 can essentially only protrude through the opening 3 of the wall 4 up to this flange 5. The flange 5 has a first surface 5.1 which points towards the inner side 4.1 of the wall 4 or housing 6. When the on-load tap-changer 1 is in the assembled state, one or more seals in the form of one or more sealing rings 21 can be arranged between the first surface 5.1 and the inner side 4.1 of the wall 4. The seal or sealing ring 21 is thus arranged between the flange module 2 and the housing 6. This prevents the escape of transformer oil which is located inside the tapped transformer 30.

[0041] The first region 10 of the flange module 2, arranged on the outer side 4.2 of the tapped transformer 30, has an at least partially formed, circumferential thread 11. The on-load tap-changer 1 is fastened to the housing 6 of the tapped transformer 30 by means of a union nut 12 having an internal thread 13. By tightening the union nut 12, the flange module 2 and thus the entire on-load tap-changer 1 is pressed against the inner side 4.1 of the housing 6 or the wall 4. The connection between the union nut 12 and the flange module 2 can also be implemented by means of locking lugs or similar. In this case, the union nut 12 is always placed on the flange module 2 to fix it. The flange module 2 is supported on the inner side of the wall 4 of the tapped transformer 30 via the flange 5. In the embodiment shown here, a cover cap 14 is clipped onto the on-load tap-changer from the outside.This serves as protection against the elements.

[0042] The flange module 2 forms part of the on-load tap-changer 1. The control unit 40 and the communication unit 41 are located in the first area 10 of the flange module 2. These are accessible from the outside, i.e., outside the tap-changer 30. The drive 42, the diverter switch 43, and the selector 50 are located in the second area 20, which is located inside the tap-changer 30. While the selector 50 is constructed of mechanical switches / contacts, the diverter switch 43 has semiconductor switching elements. The on-load tap-changer 1 is thus a so-called hybrid on-load tap-changer.

[0043] The flange module 2 has a contact carrier 60 in the area of ​​the selector 50, on which a plurality of fixed contacts 61 are arranged. The contact carrier 60 is tubular and essentially corresponds to the cross-section of the flange module 2. The contact carrier 60 can initially be designed as a separate part, but in the assembled state forms a unit with the flange module 2. The contact carrier 60 surrounds the individual elements of the selector 50 and, distributed over its circumference, holds the individual fixed contacts 61, which are connected to the individual winding taps 31 of a control winding of a tapped transformer 30.

[0044] Figure 3 shows a detailed sectional view of the selector 50, which is part of the on-load tap-changer 1. A contact carrier 60 with the fixed contacts 61 is part of the flange module 2. The selector 50 comprises a first sun gear 51, which is arranged on a drive shaft 62 and connected to the latter. The first sun gear 51 has partial toothing 69 on its circumference. Furthermore, a first planet gear 52 and a first ring gear 53 are provided. The first planet gear 52 is partially toothed on its circumference and has a partially toothed region 52 / 55. The first ring gear 53 has a first selector contact 71 on its outer contour, as well as internal toothing 67 on an inner contour. When actuated, i.e. when the drive shaft 62 is rotated, the first sun gear 51 is rotated by the drive shaft 62. The rotational movement is transmitted to the first planetary gear 52 through its toothing.Since the planetary gear is only partially toothed, the rotation is only partially transmitted to the first ring gear 53. This ensures that the first ring gear 53 is only rotated a few degrees, while the drive shaft 62 and the first sun gear 51 complete a 360-degree rotation.

[0045] The first ring gear 53 is further configured as a first selector arm, which, on the one hand, encompasses or supports the first selector contact 71 and, on the other hand, is driven via a toothing 67 and executes the movement. The first selector contact 71 is directly connected to the first ring gear 52 or arranged on it.

[0046] The selector 50 further comprises a second sun gear 54, which is arranged on the drive shaft 62 and connected thereto. The second sun gear 54 has a partial toothing 69 on its circumference. Furthermore, a second planet gear 55 and a second ring gear 56 are provided. The second planet gear 55 also has a partially toothed area 68 on its circumference. The second ring gear 56 has a second selector contact 72 on its outer contour and a toothing 67 on its inner contour. Upon actuation, i.e. the rotation of the drive shaft 62, the second sun gear 54 is rotated. The partial toothing 69 transmits the rotational movement to the second planet gear 55. Since this is only partially toothed, the rotation is only partially passed on to the second ring gear 56. This ensures that the second ring gear 56 is rotated only a few degrees, while the drive shaft 62 and the second sun gear 54 perform a 360 degree rotation.

[0047] The second ring gear 56 is thus designed as a second selector arm, which, on the one hand, encompasses or supports the second selector contact 72 and, on the other hand, is driven via a gearing and executes the movement. The second selector contact 72 is directly connected to the second ring gear 56 or arranged on it.

[0048] The first and second sun gears 51, 54, the first and second planet gears 52, 54, and the first and second ring gears 53, 56 form the planetary gear 59.

[0049] The first sun gear 51, the first planet gear 52 and the first ring gear 53 correspond to the second sun gear 54, the second planet gear 55 and the second ring gear 56, which are merely arranged one above the other in a mirror image on the drive shaft 62 in the selector 50.

[0050] Figure 4 shows part of the planetary gear 59. The second ring gear 56 has a second selector contact 72. The selector contact 72 is mechanically connected to the second ring gear 56. The second sun gear 54 is attached to the drive shaft 62. This has partial teeth 69 on its outer circumferential side. When the drive shaft 62 is actuated (rotated), the partial teeth 69 engage with the partially toothed area 68 of the second planet gear 55. The teeth of the second planet gear 55 rotate and ultimately engage with the teeth 67 of the second ring gear 56. This toothing 67 is arranged on an inner contour of the ring gear 56. During operation or when the selector 50 is actuated, the drive shaft 62 performs one or more rotations, whereas the second ring gear 56 performs only a part of a rotation, thereby creating a stepwise rotational movement of the second ring gear 56.When actuated, the second ring gear 56 rotates so far that the second selector contact 72 moves from one fixed contact 61 to the next fixed contact 61 and contacts it.

[0051] The internal toothing 67 is not formed over the entire inner contour of the ring gear 56. So-called end-position locks 73, 74 are arranged at the beginning and end of the toothing 67. In the embodiment shown here, the first and second end-position locks 73, 74 are designed as wall elements. These serve to limit the rotational movement of the second ring gear 56. This mechanically prevents the selector 50 from being actuated beyond two defined points – the end positions. The second planetary gear 55 blocks the sun gear 54 and thus the rotation of the drive shaft 62 upon reaching the end-position locks 73, 74.

[0052] The structure of the first sun gear 51, the first planet gear 52 and the first ring gear 53 corresponds to the structure of the second sun gear 54, the second planet gear 55 and the second ring gear 56. The first ring gear 53 also has two end position locks.

[0053] Figure 5 shows a detailed view of the selector 50, in particular of the contact carrier 60. It is particularly clearly visible that the fixed contacts 61 extend outward from the interior of the selector 50. Inside, the fixed contacts 61 are contacted by the first and second selector contacts 71, 72.

[0054] List of reference symbols

[0055] 1 on-load tap-changer

[0056] 2 flange module

[0057] 3 Opening

[0058] 4 wall

[0059] 4.1 Inside of 4

[0060] 4.2 Outside of 4

[0061] 5 Flange

[0062] 5.1 First area of ​​5

[0063] 6 housings

[0064] 7 lids

[0065] 10 First area

[0066] 11 threads

[0067] 12 union nut

[0068] 13 internal threads

[0069] 14 Cover cap

[0070] 20 Second area

[0071] 21 Seal or sealing ring

[0072] 30 step transformer

[0073] 31 winding taps

[0074] 32 active part

[0075] 40 Control unit

[0076] 41 Communication unit

[0077] 42 drive

[0078] 43 load diverter switches

[0079] 50 voters

[0080] 51 First sun gear

[0081] 52 First planetary gear

[0082] 53 First ring gear

[0083] 54 Second sun gear

[0084] 55 Second planetary wheel

[0085] 56 Second ring gear

[0086] 59 planetary gears

[0087] 60 contact carriers

[0088] 61 fixed contacts

[0089] 62 drive shaft

[0090] 67 Internal toothing of 53 / 56 Partially toothed area of ​​52 / 55 Partial toothing of 51 / 54 First selector contact Second selector contact First end position lock Second end position lock Permanent main contact

Claims

Patent claims 1. Load tap changer (1 ) for uninterrupted load switching between different winding taps of a tap transformer (30), comprising: a load changeover switch (43) and a selector (50); wherein - the selector (50) has a contact carrier (60) with several fixed contacts (61); the selector (50) has a planetary gear (59) with a first ring gear (53), a first planet gear (52) and a first sun gear (51); the first ring gear (53) has a first selector contact (71) for contacting the fixed contacts (61).

2. Load tap changer (1) according to claim 1, wherein - the planetary gear (59) of the selector (50) has a second ring gear (56), a second planet gear (5) and a second sun gear (54); the second ring gear (56) has a second selector contact (72) for contacting the fixed contacts (61).

3. Load tap changer (1 ) according to one of claims 1 - 2, wherein - the first ring gear (53) and / or the second ring gear (56) have a first and a second end position lock (73, 74).

4. Load tap changer (1) according to one of claims 2 to 3, wherein - the first and / or the second ring gear (53, 56) have an internal toothing (67) and the first and the second end position lock (73, 74) are designed as wall elements at a respective end of the toothing (67).

5. Load tap changer (1) according to claims 2 to 4, wherein - the first and second sun gears (51, 54) each have partial teeth (69).

6. Load tap changer (1) according to claims 2 to 5, wherein - the first and second sun gears (51, 54) are arranged one above the other on a drive shaft (62).

7. Load tap changer (1 ) according to one of claims 1 - 6, wherein - the load switch (43) has semiconductor switching elements.

8. Load tap changer (1 ) according to one of claims 1 - 7, wherein - the contact carrier (60) is tubular in design and is a separate part of a Flange module (2) is. Load tap changer (1) according to one of claim 8, wherein - the contact carrier (60) forms a unit with the flange module (2). Load tap changer (1) according to one of claims 1-9, wherein - permanent main contacts are arranged between the load changeover switch (43) and the selector (50). Stepping transformer (30) with a load tap changer (1) according to any one of claims 1 to 10, comprising: - a housing (30); an active part (32) with winding taps (31); wherein - the load tap changer (1) is arranged above and / or next to the active part - the selector (50) is electrically connected via its fixed contacts (61) to the winding taps (31) of the active part (32). Stepping transformer (30) with a load tap changer (1) according to claim 11, wherein - the load tap changer (1) is oriented horizontally or vertically.

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