BG112080A - A load tuner for regulating pressure of power transformers - Google Patents

Abstract

The load tuner is comprised of a carrier head (1), an isolation cylinder (2) and a bottom (3). In the carrier head is placed a two-step mechanism for hop shifting. It consists of a loading teeth gear (8) and two blocks (15 and 16), each comprised of one Maltese gear and one tooth gear. The upper tooth gear is clasped with another tooth gear (22), which spins internal isolation drive (24), and the lower tooth gear- with tooth gear (25), which spins pipe isolation valve (26). To the valve (24) are connected a single vacuum finger arc chamber (VAC 35) on phase with contact outlet (38) and mechanism for turning on and shutting down. To the pipe valve (26) are connected aiding VAC (52) with an analog device. They work with resistors (56). With sequential shifts an initial VAC works immediately after the other VAC. A simplified low toll construction is achieved. There is a self-replacing implementation with VAC and contact rolls, turning off arches in the transforming oil.

Description

VOLTAGE DRIVE FOR VOLTAGE ADJUSTMENT OF

POWER TRANSFORMERS

FIELD OF THE INVENTION

The invention relates to a three-phase selected under load, intended for the regulation of power transformers with windings connected in a star center or in a triangle. It uses vacuum arc quenching chambers, but there is also an interchangeable version with contact units that extinguish electric arcs in transformer oil.

BACKGROUND OF THE INVENTION

It is known to be selected under load (1), comprising a support head, an insulating cylinder and a bottom. The support head has a spring energy accumulator consisting of a spring, a drive pulley with arm and roller and a Maltese wheel.

The shaft of the Maltese wheel is connected to a tubular insulating shaft located coaxially along the axis of the insulating cylinder. Movable contact systems containing a main vacuum arc quenching chamber, an auxiliary vacuum arc quenching chamber, a current-carrying contact unit, insulating carriers and levers with rollers for controlling the vacuum arc quenching chambers are connected to this shaft. Resistors are attached to the insulating shaft. At least ten fixed contact elements are installed on the periphery of the insulating cylinder, located at 36 ° to each other. There is also a drain ring and rings for guiding the contact system and commanding the vacuum arc quenching chambers.

The disadvantage of this selected under load is that it has a large diameter of the cylinder, which increases the overall dimensions and weight. This is because the fixed contact elements must have wide current-carrying arcs to ensure correct contact during switching. Large dimensions require more space in the transformer boiler. Another disadvantage is that the assembly and disassembly of the movable contact system in the insulating cylinder is difficult.

Reduction of the overall dimensions can be achieved by using a spring-energy accumulator with two-stage switching. Such a selector is known under load (2) the spring-energy accumulator on which it contains a spring, a gear with the possibility of free angular travel and a transfer with a roller. The translation activates a Maltese cross connected to another gear and a double translation with two offset angle rollers. When switching, the rollers actuate two Maltese wheels in series, one of which is connected to a hollow insulating shaft and the other to an insulating shaft located in the hollow shaft. A movable contact system is mounted to each of these shafts.

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The disadvantage of this selected load is that it has a complex spring-loaded battery, which takes up a lot of space in the support head. Another disadvantage is that this selected under load can not work with vacuum arc quenching chambers.

SUMMARY OF THE INVENTION

The object of the invention is to provide a selectable load having a simplified two-stage switching system providing small transverse dimensions and weight. Contact systems with both vacuum arc quenching chambers and contact systems with arc quenching in transformer oil can be used. The assembly and disassembly of the removable part can be done easily and without difficulty.

The problem is solved with a three-phase selected under load, containing a bearing head, an insulating cylinder and a bottom. The support head has a two-stage switching mechanism connected to insulating shafts bearing movable contact systems. Ten or more fixed contact elements are arranged on the inner periphery of the insulating cylinder.

According to the invention, the two-stage switching mechanism comprises a vertical axis mounted on a bearing flange. Two blocks are mounted on the axle, each consisting of one Maltese wheel and one gear wheel. The Maltese wheels are powered by a double translation, which has two arms with rollers located at a certain angle to each other. This angle is consistent with the angle between the grooves of the Maltese wheels. It is preferable for the Maltese wheels to have six channels. The angle between the two shoulders is similar

of the double translation, the aim being that the rotation of one Maltese wheel does not overlap with the rotation of the other Maltese wheel.

The double gear is actuated by a gear wheel mounted above it, to the periphery of which one end of a switching spring is connected. There is a suitable freewheel clutch between the double gear and the gear.

The gear from the upper block is engaged with a gear mounted to a metal shaft, which is extended by an internal insulating shaft. The gear from the lower block is engaged with a gear connected to a tubular insulating shaft.

In the case of a variant with vacuum arc-quenching chambers (VDK), one main VDK per phase is attached to the inner insulating shaft by means of supports. It has an upper flange with a contact unit connected alternately to the fixed contact elements and a lower flange with a current-carrying contact sliding on a ring mounted on the inner surface of the insulating cylinder. The auxiliary VDK is mounted on the tubular insulating shaft and has a design similar to that of the main VDK. Both VDK have a mechanism that is mounted to the lower flange and serves to properly turn on and off the VDK. The auxiliary contact system also has a radial rail with a contact node that contacts the extension of the fixed contact elements. A resistor is connected between this bus and the upper flange of the auxiliary VDK.

In the case of an arc-quenching in oil, a U-shaped bracket is attached to the supports of the inner insulating shaft, at one end of which there are contact arc-quenching rollers, and at the other - a current-carrying contact. A carrier with auxiliary contact rollers is attached to the tubular insulating shaft. An advantage of the voter under load is that a construction with small ······· · · ···· ·· ·· ·· ······ overall dimensions and weight is obtained. A different number of positions are provided only by changing the gear ratios of the gears. At the same time, the mechanisms are simplified and take up less space.

Another advantage is that it provides a unified design, both with the use of vacuum arc quenching chambers and by roller contact elements for arc quenching in the transformer oil.

EXPLANATION OF THE ATTACHED FIGURES

An exemplary embodiment of the three-phase selector under load according to the invention is shown in the attached figures, of which:

Figure 1 is a longitudinal section of a three-phase selector under load.

Figure 2 - top view of the mechanisms in the support head.

Figure 3 is a cross-sectional view above the two-stage switching system.

Figure 4 - cross section over the two vacuum arc quenching chambers and their contact system. In the right half is a bottom view of the two vacuum arc quenching chambers.

Figure 5 - longitudinal section in two variants of contact systems for arc quenching in oil: I - vertically located movable contact rollers; II horizontally arranged movable contact rollers.

EXAMPLES OF EMBODIMENT OF THE INVENTION

The load selector has a support head 1, an insulating cylinder 2 and a bottom (Fig. 1). A flange 4 with a cover 5 is mounted on top, on which a known one is attached

worm gearbox 6 with drive shaft 7. The shaft is connected to a drive gear 8, which is engaged with a gear 9 of a switching spring 10 (Fig. 2). One end 11 of the spring is mounted to a gear 9 and the other end 12 is attached to a bearing flange 13. On the flange 13 is mounted a vertical axis 14 on which are mounted two blocks 15 and 16, each consisting of one Maltese wheel and one gear (Fig. 3). Gear 9 is mounted on an axle 17 mounted on the flange 13 and interacts with a double gear 18 mounted below it. It has two arms with rollers 19 and 20, which periodically interact with the Maltese wheels 15 and 16. The two arms 19 and 20 are located at a certain angle corresponding to the angle of the grooves of the Maltese wheels 15 and 16. One roller is directed upwards and the other downwards.

The gear 21 of block 15 is connected to a gear 22 attached to a centrally located metal shaft 23 to which an insulating shaft 24 is mounted. The gear 21 of block 16 is connected to a gear 25 mounted to an insulating tubular shaft 26.

Gear 8 has a roller 27, which is connected to a Maltese wheel 28, intended for digital display of positions and actuation of a preselector. This is done in a known manner by a gear 29, a shaft 30, an arm 31 and a shaft 32 with an arm 33 which switches a known unselected preselector.

The movable contact systems of the three phased X, Y and Z phases are mounted to the shaft 24 by means of brackets 34. 37 (Fig. 1, Fig. 4). A main discharge contact assembly 38 is connected to the flange, which is in contact with fixed contact elements 39 mounted to the insulating cylinder 2. The movable terminal 40 of the VDK 35 is connected to an L-shaped lever 41 with a contact roller. ··. . : ···.

···· ·· ·· ·· ······ and contact spring 43. The lever 41 swings on an axis 44 mounted on a support 45 connected to the lower flange 46 of VDK 35. To the lower flange 46 of VDK 35 is connected a drain contact 47, which is in contact with a metal ring 48 mounted to the cylinder 2, through drain contacts 49. The metal ring 48 also has an insulating ring 50 with channels 51 for switching the VDK on and off.

An auxiliary VDK 52 is attached to the tubular insulating shaft 26 with a device similar to that of the VDK 35. A radial rail 53 with an auxiliary contact unit 54 is attached to the shaft 26, which contacts an elongated tail 55 of contact 39. Resistors 56 are attached to shaft 26. which are connected between the rail 53 and the upper flange 37 of the auxiliary VDK 52. The two shafts 24 and 26 are mounted 56 to the bottom 3. The contact spring 43 is connected between the lower flange 46 and the elongated tail 57 of the lever 41.

In FIG. 5 shows two variants of contact systems with arc quenching in oil. They are simpler and cheaper and are preferred by some users. The fixed contact elements 58 are mounted to a cylinder 2. In variant I, the movable contact rollers, main 59 and auxiliary 60, have a vertical axis. A roller 60 is on a carrier 61 attached to a shaft 26, and a roller 59 is on a Porous carrier 62 mounted by a carrier 34 to a shaft 24. There are also contact springs 63. A current contact 64 in contact with a ring 65 is also attached to the carrier 62. When lime. II construction is similar, but the contact rollers 66 have horizontal axes.

The action of the selector under load when switching is carried out as follows: through the gearbox 6 and the shaft 7 the gear 8 performs one switching turn (Fig. 1 and Fig. 2). One turn also makes a gear 9, after 180 ° the spring 10 is stretched to the maximum and reaches an upper dead center. After ’:. ::. ·· .. *: ···.

···· ·· ·· ·· ······ it is released and rotates the double translation 18 (Fig. 3). Thus, the rollers 20 and 19 rotate the two Maltese wheels 15 and 16 in succession, and through them the gears 22 and 25, respectively the shafts 24 and 26. Thus, the required two-stage switching of the main VDK 35 and the auxiliary VDK 52 takes place. channels 51 and open the respective VDCs, whereby the transfer of contacts 38 and 54 from one contact 39 to the neighboring one becomes current-free. The supports 34 rotate unimpeded in one angular step, since grooves 26 are provided at the periphery on the shaft 26.

The operation of the pre-selector mechanisms is known and will not be described.

Claims (4)

PATENT CLAIMS 1. Selector under load for voltage regulation of power transformers, comprising a bearing head, an insulating cylinder and a bottom, the carrier head having a two-stage switching mechanism connected to insulating shafts bearing movable contact systems, and on the inner periphery of the insulating cylinder a number of fixed contact elements, characterized in that on the axle (14) mounted on a bearing flange (13) are mounted two blocks (15 and 16), consisting of one Maltese wheel and one gear, the Maltese wheels being connected by a double gear (18) with two arms with rollers (19 and 20) located at a certain angle corresponding to the angle of the grooves of the Maltese wheels, and the gears are connected respectively by one gear (22) mounted on a metal shaft 23) extended by an inner insulating shaft (24) and a gear wheel (25) mounted on a tubular insulating shaft (26), the main insulating shaft (24) being connected by main contacts to the inner insulating shaft (24). systems, and auxiliary contact systems and resistors (56) are connected to the tubular insulating shaft (26). Load selector according to claim 1, characterized in that it is preferable that the Maltese wheels (15, 16) have six channels each, and that the angle between the arms (19, 20) of the double translation (18) is such that the rotation of one step of one Maltese wheel does not overlap with the rotation of the other Maltese wheel, and the number of teeth of the wheels (21, respectively 22 and 25) can be changed in order to ensure a different number of positions . Selected under load according to claims 1 and 2, characterized in that the main contact system for each phase consists of a main VDC (35) mounted in an insulating support (36) and comprising an upper flange (37) with a contact assembly (38), a lower flange (46) with a current-carrying contact unit (47) and a VDK on / off control system, and the auxiliary contact system has an auxiliary VDK (52) with a device similar to the main VDK (35) and a bracket (53 ) with contacts (54), which together with the resistors (56) is mounted to the tubular insulating shaft (26), the resistors being connected between the carrier (53) and the upper flange of the auxiliary VDK (52). Load selector according to claims 1 and 2, characterized in that a U-shaped carrier (62) with contact arc-quenching rollers (59) is attached to the support (34) of the central insulating shaft (24) on one side and current-carrying contact (64) - on the other side, and a support (61) with auxiliary contact arc-quenching rollers (60) is attached to the tubular insulating shaft (26).