BG67123B1 - Selector with preselector for on-load tap changer - Google Patents

Abstract

The selector comprises an upper metal flange (1) with a housing (6), a lower metal flange (2) and fastened between them fixed number of segments (3), cutted from an insulation cylinder and arranged in a cage-like manner. On the segments there are mounted in tiers odd (4) and even (5) stationary contact elements. In the centre of the selector there is an insulating tube (7) with even (9) and, odd (8) current-carrying rings arranged in tiers thereon. To them are connected conductors (13) passing upwards in the insulating tube. The selector actuating system is located in the body (6). It is composed of a drive shaft (31) with a double transmission (25). On an adjacent axis (32) are mounted via bearings an even unit (26) and an odd unit (27) each of which is composed from one Geneva drive wheel (28) and one toothed gear (29). These toothed gear are engaged with one large even toothed gear (16) and one large odd toothed gear (19). They are mounted via rolling-contact bearings (15) coaxially at the top section of the insulation tube (7). To the elongated cylindrical portion (17) of the toothed gear (16) is attached an even drive segment (18) cutted from an insulation cylinder. An analogous odd drive sector (21) is connected to the metal sector (20) of the toothed gear (19). The two drive sectors have profile-cut lugs to which are fastened the contact carriers (35) of the contact pins (36). The selector is of known construction and is mounted sideways to the selector. It has a simplified and compact actuating system of Geneva drive sector (50) with a toothed rim, engaged with toothed rim of a actuating arm (48).

Description

Field of technology

The invention relates to a selector with a preselector, which is used in a step voltage regulator. Step regulators are built into the power transformers and regulate their high voltage under load, ie without interrupting the power supply to consumers. The pre-selector is three-phase and is used for star center windings.

BACKGROUND OF THE INVENTION

Known voters are compared, which have a central insulating pipe with current-carrying rings arranged on it and connected wires passing inside the central pipe upwards to the oil vessel of the step regulator. The pre-selector is mounted on the side of the voter.

A three-phase selector with a preselector [1] is known, comprising an insulating central tube, on which six conductive rings are arranged in layers, one even and one odd for each phase. A wire is connected to each ring, the six wires being located inside the pipe. They pass vertically upwards to the bottom of the oil tank, in which a power switch is built-in. Between the upper housing and the lower flange are attached columns of insulating rails, on which fixed contact elements are mounted. In the upper body there are two Maltese wheels located one below the other concentrically on the central tube. The Maltese wheels are rotated alternately by a double gear with two pairs of drive rollers located 180 ° to each other. The Maltese wheels rotate in two successive steps at a certain angle, depending on whether 10 positions or 12 positions or more are required. Therefore, the Maltese wheels and the double translation are different for the specific number of situations. Attached to each Maltese wheel is a drive column composed of insulating rails carrying movable contact bridges that connect the guide rings to the fixed contact elements. The pre-selector is mounted on the side of the voter. It contains two insulating columns of rails bearing fixed contact elements and driving rails with movable contact bridges. The insulation columns are reinforced with profile plastic arches.

The disadvantage of this pre-selector is that the Maltese wheels are large in size and complicated to make. If the dimensions are not correct, the Maltese gear can lock. For a different number of situations, the Maltese gears are different, which makes production difficult. Another disadvantage is that the entire load-bearing structure requires strong and straight insulation rails in order to ensure stability. Another disadvantage is that the fixed even and odd contact elements are not arranged in series, which increases the requirements for insulation distances. Another disadvantage is that the design of the pre-selector is complicated.

Another selector with a preselector [2] is also known, also comprising a central tube with contact rings and wires passing vertically inside it and a cage of insulating rails attached between the upper housing and the lower flange. Fixed contact elements are mounted on the rails, which are arranged here in sequence. The housing has a Maltese gear of two Maltese wheels with large dimensions and complex configuration in order to achieve rotation at two different angles. The movable contact bridges are mounted on profile insulating girders, sliding on the contact rings, which have a special profile. They are driven by vertical columns. The pre-selector is located on the side of the selector and has a complex structure with large contact nodes.

The disadvantage of this selector is that it has large dimensions and complex construction. Maltese gears are large and complex and require very precise workmanship. For different numbers of situations are different, which complicates the production. Another disadvantage is that the pre-selector also has a complicated construction and relatively large dimensions.

A selector [3] is also known, in which the fixed contact elements are mounted on sectors cut out of an insulating glass roving cylinder. Even and odd contact rings are arranged on the central insulation pipe, and six wires are placed in it, passing upwards to the bottom of the oil vessel. Maltese gears and pre-selector are not shown, but they are assumed

Descriptions of issued patents for inventions № 09.1 / 15.09.2020 are similar to those of [1]. The insulation sectors are attached to the upper body and lower flange. The contact bridges are driven by vertical columns of insulating rails.

The disadvantage of this selector is that the fixed contact elements are not arranged in series, which impairs the insulation coordination. Other disadvantages are similar to those of [1].

Technical essence of the invention

The object of the invention is to provide a selector with a pre-selector for a step voltage regulator which has a compact, simple and stable construction. To be with a central pipe with six conductive rings arranged in layers, six conductors are connected, passing axially inside the pipe. Maltese gears should be simplified and unified for 10, 12 and 14 positions. The supports of the movable contact bridges should be stable with a small number of simple elements, providing work with sequentially arranged fixed contact elements. The pre-selector should be located on the side of the selector and have a simple and stable construction.

The problem is solved with a selector with a preselector for a step voltage regulator, containing an upper metal flange and a lower metal flange with cage-shaped segments of insulating material, on which even and odd fixed contact elements are mounted. In the center of the voter there is an insulating pipe with even and odd current-carrying rings arranged on it in layers, which are connected by wires passing vertically upwards inside the pipe. Above the upper shield is mounted a housing with a drive system located in it is Maltese mechanisms, which are connected to vertical drive columns carrying movable current-carrying contact pins. A pre-selector with movable and fixed contact elements is located on the side of the selector.

According to the invention, the drive system consists of a double gear attached to a drive shaft. On one side of the double translation there are two pins with rollers, which are located at a certain angle to each other. On the other side of the double translation, opposite 180 °, there are also two roller pins. An even block consisting of a Maltese wheel and a gear and a similar odd block consisting of a Maltese wheel and a gear wheel are mounted on a vertical axis parallel to the drive shaft. The gear of the even block is engaged with a larger even gear mounted coaxially at the upper end of the central tube. At the elongated cylindrical end of this gear is mounted an odd gear with the same number of teeth, which is engaged with the gear of the odd block.

To the elongated cylindrical part of the even large gear wheel is attached an even driving insulating segment with profile-cut lugs, on which are mounted brackets with even contact pins with contact springs. Attached to an elongated segment of the odd large gear wheel is an odd driving insulating segment with profile-cut lugs, on which there are supports with odd contact pins.

The Maltese wheels of the two blocks have six channels with an angle between them of 60 °. The angle between the two pins with double translation rollers is similar. It complies with the requirement that when the double translation is rotated 180 °, the Maltese wheel rotates smoothly and continuously in two steps of a total of 120 °.

In the 10, 12 and 14 position selectors, the double gear and the Maltese wheels do not change, and the achievement of the respective angles of rotation in a shift of 72 °, 60 ° and 51 ° 26 'is achieved by changing the gear ratio between the gears. The center distance is the same.

The large even and odd gears are coaxially mounted on the central tube by rolling bearings.

In a different number of positions, respectively a different number of fixed contact elements per phase, there may be a different number of insulating segments, but it is recommended that for 12 positions the segments be four pieces with three contact elements each. For 14 positions, it is recommended that the segments be four, of which two segments with three contact elements each and two segments with four contact elements each. For 10 positions a good option is five segments with two contact elements. The arrangement of the insulation segments must be such that it is always between the first and the last contact number

Descriptions of issued patents for inventions № 09.1 / 15.09.2020 element to have oil insulation.

The drive of the pre-selector is characterized by the fact that on the axis of the two blocks with gears and Maltese wheels is mounted a Maltese sector with a gear ring. The sector is connected on one side by a pin with a roller, which is mounted on a disk connected to the large odd gear. On the other hand, the Maltese sector is connected by its ring gear to a ring gear mounted on the drive shaft of the double gear. The arm is connected to vertical insulating rails carrying movable contact pins of the pre-selector.

An advantage of the selector with a pre-selector for a step voltage regulator according to the invention is that it has a simple, small-sized and light construction. Another advantage is that the Maltese wheels are the same in a different number of positions. In general, they are more difficult to make than gears, for which there are specialized high-performance machines.

Another advantage is that the large gears are mounted coaxially on the central tube by rolling bearings due to the fact that their outer diameters are relatively small. This results in a stable attachment of the drive sectors and their slight rotation. The sectors are shaped in such a way that the gripping of the carriers of the movable contact pins does not require additional elements. Linear arrangement of the fixed contact elements is guaranteed, as there is an oil insulation distance between the first and the last number of contact elements. As an advantage, the voter drive system is simple and stable.

Explanation of the attached figures

An exemplary embodiment of the selector with a pre-selector for a step voltage regulator according to the invention is shown in the attached figures, of which:

Figure 1 is a longitudinal section through the selector and the pre-selector.

Figure 2 - Cross section over the Maltese and gears.

Figure 3 is a cross-sectional view of the pre-selector actuators.

Figure 4 - cross section over the contact systems.

Figure 5 is a longitudinal section showing a front view of the movable contact bridge girders.

Examples of the invention

Between the upper metal flange 1 and the lower metal flange 2 are fixed a number of segments 3, cut by an insulating cylinder and arranged as a round cage. Odd fixed fixed contact elements 4 and even fixed fixed contact elements 5 are mounted on the segments 3. A housing 6 is located on the flange 1, in which the selector drive mechanisms are placed. In the center of the selector to the housing 6 above and the lower flange 2 below is attached an insulating tube 7, around which are mounted odd conductive rings 8 and even conductive rings 9. The central tube 7 is connected to the housing 6 by a ring 10 and the lower flange 2 - through an axis 11 with a flange 12. Inside the central tube 7 are six wires 13, three of which are connected to the odd conductive rings 8 and three - with the even conductive rings 9. The conductors 13 pass up into the central tube 7 and above the housing 6 have bent ends 14 through which they are connected in a known manner to an oil tank and a power switch not shown.

An even drive gear 16 is mounted on the ring 10 by a rolling bearing 15, connected by its cylindrical end 17 to an even drive insulation segment 18. An odd gear 19 is mounted on the end 17, the elongated segment 20 of which is connected to an odd drive segment. 21. At their lower end, the two segments 18 and 21 have arms 22 and 23 through which 24 are mounted on the shaft 11. The two gears 16 and 19 rotate alternately at a certain angle by a double gear 25 by two blocks 26 and 27 composed of of one Maltese wheel 28 and one gear 29. The double gear 25 has four pins with rollers 30, two on one side and two on the other. It is mounted on a drive shaft 31, which is rotated in a known manner by a freewheel clutch not shown. The two blocks 26 and ΊΊ are mounted on an axis 32. The conductors 13 are reinforced in their upper part by an insulating plate 33 with fixed channels. It is mounted on top of the housing 6.

The even insulating segment 18 has profile cut-out lugs 34 to which supports 35 are attached.

Descriptions of issued patents for inventions № 09.1 / 15.09.2020 with contact pins 36 with contact springs 37 mounted on them. Similarly, the odd insulating segment 21 has lugs 38 on which such carriers 35 with contact pins 36 and contact springs are also mounted. 37.

In the considered example there are 12 pcs. fixed contact elements arranged sequentially clockwise. The odd contact elements 1, 3, 5, 7, 9, 11 occupy the top row of each phase, and the even 2, 4, 6, 8, 10, 12 (K) are arranged below them. There are voters in which the even contact elements are above and the odd ones below them, but this does not change the essence of the invention.

The pre-selector, designed as a reverser, is located on the side of the selector. It has an upper sector 38 and a lower sector 39, between which is attached an insulating segment 40, on which are mounted two fixed contact elements 41 and 42 per phase. To the end contact elements 5 are attached L-shaped conductive elements 43. With them and alternatively - is the contact elements 41 and 42, contact contact pins 44 is contact springs 45. The pins 44 are attached to supports 46 mounted on insulating rails 47, which above are attached to a shoulder with a ring gear 48, and below - to a shoulder 49, bearing to the lower sector 39. The arm 48 is a bearing of a shaft 31, and its ring gear is engaged with a gear ring of the Maltese sector 50, mounted on a shaft 32. To the segment 20 of the odd gear 19 is mounted a disk 51 is a pin with a roller 52. The disk 51 rubs with its ring on the corresponding arm of the Maltese sector 50 and locks it in normal working position.

The action of the voter is a pre-voter is as follows.

In the drawings, the even movable contact pins 36 connect the even contact rings 9 is a fixed even contact element 5 located in the twelfth position connected to the preselector. The selector is for twelve positions, ie it has six odd contact elements 4 and six even contact elements 5 in one phase. The odd movable contact thumbs are in the first position. During the transition from the eleventh to the first position, the pre-selector is activated and the contact pins 44 have passed from the contact element 42 to the contact element 41. The current flows through the contact circuit in the first position. When reversing the movement, due to the presence of a freewheel clutch, the shaft 31 rotates at a small angle counterclockwise and the contact systems of the selector remain stationary, and only the power switch switches. The current is already flowing through the contact elements of the twelfth position. When the shaft 31 is further rotated 180 ° counterclockwise, the double gear 25 overturns in two successive steps the Maltese wheel ΊΊ of the odd gear, as a result of which the gear wheel 19 is also a disk 51 rotates counterclockwise. at 30 °. The odd contact thumbs pass from the first position to the eleventh. A pin is a roll 52 turning the Maltese sector 50 and the contact pins 44 of the pre-selector pass from the contact element 41 to 42.

Claims (8)

1. A selector is a pre-selector for a step voltage regulator, containing an upper metal flange and a lower metal flange with segmented segments of insulating material between them. There are fixed even and odd contact elements, and in the center of the selector there is an insulating tube. and odd conductive rings connected by wires passing vertically upwards, inside the tube above the upper shield is mounted a housing with a drive system located in it is Maltese mechanisms connected by vertical drive columns bearing movable conductive contact pins, and laterally to the selector is located preselector is a movable and fixed contact elements, characterized in that the drive system consists of a double translation (25) is two pins is rollers (30) located at a certain angle on one side and two similar pins with rollers located at 180 ° on the other side, on a parallel vertical axis are mounted an even block (26) of Maltese wheel (28) and h gear (29) and mounted below it an odd block (27) of Maltese and gear, the even gear (29) is engaged is a large even gear (16), bearing coaxially on the upper end of the central tube (7), under At its elongated cylindrical end (17) is a bearing odd gear (19) engaged with the gear (29) of the odd block (27), and to the elongated cylindrical end (17) of the even gear (16) is attached an even driving Descriptions of issued patents for inventions № 09.1 / 15.09.2020 insulating segment (18) with profile cut-out lugs (38), on which mounts (35) with even contact pins (36) with contact springs (37) are mounted, and to an extended a segment (20) of the odd gear (19) is attached to an odd drive segment (21) with profile-cut lugs (34), on which there are supports (35) with odd contact pins (36). Selector with pre-selector for step voltage regulator according to claim 1, characterized in that the Maltese wheels (28) of the two blocks (26, 27) have six channels each with an angle between them of 60 °. Selector with pre-selector for step voltage regulator according to Claims 1, 2 and 3, characterized in that the gears (16 and 19) are mounted by rolling bearings. Selector with pre-selector for step voltage regulator according to Claims 1, 2, 3 and 4, characterized in that in a different number of positions, respectively a different number of fixed contact elements (4, 5) per phase, there are a different number of insulating segments (3), in which there is also oil insulation between the first and the last contact element by number. Selector with pre-selector for step voltage regulator according to claim 4, characterized in that in 12 positions the segments (3) are four pieces with three contact elements (4, 5). Selector with preselector for step voltage regulator according to Claim 4, characterized in that in 14 positions the segments (3) are two with three contact elements (4, 5) and two segments (3) with four contact elements each. element (4, 5). Selector with preselector for step voltage regulator according to Claim 4, characterized in that in 10 positions the segments (3) are five with two contact elements (4, 5). Selector with preselector for step voltage regulator according to claims 1, 2, 3 and 4, characterized in that on the axis (32) under the block (27) is mounted a Maltese sector with a toothed ring (50), which from one it is connected on its side with a pin with a roller (52) mounted on a disk (51) attached to the gear (19), and on the other side it is connected with a gear ring on a shoulder (48) mounted on the drive shaft (31) of the the double translation (25), the arm (48) being connected by vertical insulating rails (47) bearing movable contact pins (44) of the preselector.