BG66820B1 - Single-phase power switch with two vacuum arc-suppression chambers for on-load tap-changer - Google Patents

Abstract

(57) The single-phase power switch is applied in a on-load tap-changer with three phases located one above the other phases in one column. One main vacuum arc-suppressing chamber VAC (V1) and one auxiliary VAC (V2) are are located stationary next to each other to the inner wall of a split up insulation cylinder (18) and are fastened to the upper insulation disk (19). Centrally to the insulation cylinder (18) between the upper disk (19) and a lower disk (20) is mounted via bearings the main actuating shaft (5), which is connected to the main contact system consisting of a large contact arc (1), a small contact arc (3) and a movable contact assembly (4). Axially to the shaft (5) is mounted a hollow insulating shaft (10), which is connected to the contact system consisting of a large contact arc (6), a small contact arc (8) and a movable contact assembly (9). The shaft (5) has a toe cam (14) for actuating the main VAC (V1), and the shaft (10) has a toe cam (15) for actuating the auxiliary VAC (V2). By means of a coupling with an angular clearance, the shaft (5) rotates the shaft (10) always in the last third of the switching angle. This ensures switching of the operating current from the main VAC (V1) and of the circulating current - from the auxiliary VAC (V2). 5 claims, 8 figures A declaration of license readiness has been submitted in accordance with Art. 30 of the Law on Patents and Utility Model Registration.

Description

Field of technology

The invention relates to a single-phase power switch for a step voltage regulator of column type. It is built into the oil space of a power transformer and serves to regulate its voltage under load. The power switch has two vacuum arc quenching chambers - main and auxiliary.

BACKGROUND OF THE INVENTION

A single-phase power switch / 1 / with one main and one auxiliary vacuum arc quenching chambers (VDK) is known. The two VDCs are located inside a lengthwise insulated cylinder. The power switch has an axially located drive shaft mounted between the upper and lower disc. The contact system and the mechanism for actuating the movable contact elements of VDK are connected to this shaft. By rotating the drive shaft 180 ° in one switch, synchronized operation of the contact system and VDK is ensured.

The disadvantage of this single-phase power switch is that the main VDK is overloaded as it switches the sum of operating and circulating current. This leads to reduced switching parameters concerning the rated current and the step voltage.

Another disadvantage is that the construction is complicated because there are additional contact elements for connecting the resistor.

Another disadvantage is that the VDCs rotate when switching, which makes them more unstable.

A power switch / 2 / is also known, in which the main VDK switches off only the operating current, and the auxiliary VDK only the circulating current. This power switch is three-phase, each phase occupying a sector of 120 °.

The disadvantage of this power switch is that the contact system is located above the VDK, which complicates the construction and increases the overall dimensions. This embodiment cannot provide a compact single-phase power switch for a column-type step controller.

Technical essence of the invention

The object of the invention is to create a single-phase power switch with two VDK - main and auxiliary, as the main VDK should turn off only the operating current, and the auxiliary VDK only the circulating current. Three single-phase power switches are arranged in floors and form a column-type step controller, which can have isolated phases.

The problem is solved with a single-phase power switch for step voltage regulator, comprising a longitudinally cut insulating cylinder with a main vacuum arc quenching chamber (VDK) and an auxiliary VDK and a drive shaft mounted between the upper disk and the lower disk. Large contact arcs are attached to the inner surface of the insulating cylinder. Both VDCs are actuated by a lever and cam mechanism.

According to the invention, the main VDK and the auxiliary VDK are fixed to each other next to one inner wall of the insulating cylinder. On the opposite inner wall of the insulating cylinder are attached on two floors a main large contact arc and an auxiliary large contact arc. Against these arcs there is a small contact arc. The large main and small main contact arcs are connected to a movable contact unit, which is actuated by a centrally mounted between the upper disk and the lower disk drive shaft. Concentrically on this shaft is mounted a hollow drive shaft isolated relative to it. An auxiliary contact node is attached to the hollow shaft, connecting the large and small auxiliary contact arcs. The main VDK and the auxiliary VDK have separate drive cams. The interaction between the two shafts takes place through a sector and an arm, between which there is a free angular travel. In one variant, the cam for the main VDK is mounted on the drive shaft and the cam for the auxiliary VDK is mounted on the hollow shaft. In another variant, the two cams are towards the drive shaft. A buffer arm is attached to the hollow insulating shaft. Pre

Descriptions of issued patents for inventions № 02.2 / 28.02.2019 the inclusion takes place by turning the main drive shaft at an angle a, as three steps are characteristic - a / 3. During the first, only the main contact node is activated, during the second - the main VDK and during the third - the auxiliary VDK.

An advantage of the single-phase power switch is that the main VDK in all switches interrupts only the operating current, and the auxiliary VDK - the circulating current. This increases the rated current and the step voltage. Another advantage is that the VDK are stationary and are not loaded by inertial forces when switching.

Explanation of the attached figures

An exemplary embodiment of the single-phase power switch for step voltage regulator according to the invention is shown in the attached figures, of which:

Figure 1 is an electro-kinematic diagram of a single-phase power switch;

Figure 2 - sequence of action of VDK and contact systems depending on the angle of rotation of the drive shafts;

Option I - action of the structure of figure 3 and figure 6;

Option II - action of the structure of figure 7 and figure 8;

Figure 3 is a longitudinal section through the single-phase power switch of Option I;

Figure 4 is a cross-sectional view above the main contact system;

Figure 5 is a cross-sectional view above the auxiliary contact system;

Figure 6 is a cross-sectional view above the VDK actuating mechanism in Option I;

Figure 7 is a longitudinal section through the single-phase power switch of Option II;

Figure 8 is a cross-sectional view of the VDC actuation mechanism in Option II.

Examples of the invention

The main contact system Kj of the single-phase power switch consists of (Figure 1) a large contact arc 1 with an insulating gap 2, a small contact arc 3 and a movable contact unit 4 which connects them. The latter rotates abruptly when switching an angle a from a central drive shaft 5. The auxiliary contact system K ₂ consists of a large contact arc 6 with an insulating gap 7, a small contact arc 8 and a movable contact unit 9 which rotates from a hollow shaft 10, mounted concentrically on shaft 5 and isolated relative to it.

The main VDK - V is connected between the small contact arc 3 and the common terminal 0 and through the contact unit 4 has a connection with the operating deviation N of the step winding 11. Similarly, the auxiliary VDK - V _; is connected between N and 0, by the large contact arc 6, the contact node 9, the small contact arc 8 and the resistor R. After switching V and V ₂ are connected to the deviation Ν V is activated by the schematically shown mechanism 12, and V ₂ by the mechanism 13. The mechanism 12 is controlled by a cam 14 mounted on a shaft 5, and the mechanism 13 by a cam 15 mounted on a shaft 10. The drive shaft 5 has a sector 16, which at the end of switching acts on the arm 17 of the shaft 10. Between elements 16 and 17 has a certain angular clearance.

Figure 2 shows, during a switch, when the switching systems are closed (hatched fields) and when they are open (unshaded fields). In both variants I and II, V always opens in the middle range (about a / 3, in this case a = 180 °).

When V is open, Kj is switched arc-free and in both cases K ₂ is switched arc-free at the end of the switch, and due to the clearance between 16 and 17 this happens in all successive switches. V ₂ in variant I is closed at steady state and opens and closes within the last interval a / 3. In variant II V ₂ is open in the stationary position and closes only within the middle range a / 3. How this happens will be seen in the following figures. In these figures the numbering of the elements of Figure 1 is preserved.

The power switch is located in a longitudinally cut in half insulating cylinder 18. Shaft 5 is mounted between the upper insulation disk 19 and the lower metal disk 20, by rolling bearings 21 and 22 (Figure 3, Figure 4, Figure 5, Figure 6, Figure 7 and Figure 8). An insulating shaft 10 is mounted coaxially on shaft 5 through bearings 23 and 24. The two vacuum arc quenching chambers

Descriptions of issued patents for inventions № 02.2 / 28.02.2019

V and V ₂ are located next to each other at one end of the insulating cylinder 18. They are fixed by brackets 25 to the upper disk 19. The movable contact element 26 of the VDK is connected to a drive mechanism consisting of a L-shaped lever 27 with a bearing or roller 28. The contact pressure between the contacts inside the VDK is carried out by a spring 29. Opposite the VDK to the inner surface of the insulating cylinder 18 on two floors are located the two large contact arcs 1 and 6. The main small contact arc 3 is attached directly to the carrier 25 of V _{r The} auxiliary small contact arc 8 is mounted on two columns 30 attached to the lower disk 20. The movable contact unit 4 consists of two parallel contact lamellas 4.1 and 4.2. The contact pressure is provided by a spring 31.

According to variant I, a sleeve 32 is mounted in the lower part of the shaft 5, on which the cam 14 and the sector 16 are formed. The insulating shaft 10 has in its lower part a metal element with a cam 15 and a arm 17. A buffer 33 is mounted to the arm. delimits in the end positions of the arc 34 with limiting elements 35 (Figure 6). Attached to the movable contact element 26 of the VDK is a flexible copper braid 36 connected in a known manner to the lower disk 20. The drive shaft 5 may have a slotted end or a slotted hole 37. The connection between the phases is made through them with intermediate shafts not shown. and the bearing head.

In variant II (Figure 7, Figure 8) the two cams 14 and 15 are mounted on a shaft 5 and the shaft 10 is mounted higher and is connected to the arm 17 and the buffer 33 by an insulating element 38. The interaction between the sector 16 and the arm 17 is as in option I.

The operation of the single-phase power switch is as follows.

In the initial position, the contact bridge 4 is in the extreme left position (Figure 1, Figure 4), and the contact bridge 9 in the middle position. The cam 14 is 90 ° from the radial axis of the V and the cam 15 is in the middle position. In the case of abrupt rotation of shaft 4 of the unknown spring energy accumulator not shown, the contact bridge 4 rotates at an angle a (in the case of 180 °). There are three zones of angles a / 3 (60 °). During the first, only the contact bridge 4 rotates. In the middle zone, the cam 14 is turned off

V (Figure 2) and 4 pass the current-free insulation gap 2. At the end of this zone, V is switched on and V ₂ is switched off, so that 9 also passes current-free gap 7. Finally, V ₂ is switched on. Due to the presence of an angular clearance between 16 and 17, at each subsequent switch V only interrupts the operating current and V ₂ only the circulating current. In variant II the same result is obtained, but V ₂ is included in the middle zone and excluded in the first and third zones. This is due to the fact that the cam 25 has a different shape and is mounted on a shaft 5.

Claims (5)

1. Single-phase power switch with two arc-quenching chambers for step voltage regulator, comprising a longitudinally cut insulating cylinder, with a main vacuum arc-quenching chamber (VDK) and an auxiliary VDK located inside, a drive shaft housed between a large disk and an upper disk arcs mounted on the inner surface of the insulating cylinder and a lever and cam mechanism for actuating the VDK, characterized in that the main VDK (V)) and the auxiliary VDK (V ₂ ) are fixed to each other to one inner wall of the the insulating cylinder (16), on the opposite inner wall are attached on two floors a main large contact arc (1) and the auxiliary large contact arc (6), against which there is a small contact arc (3, 8), as the main large (1 ) and a small (3) contact arcs are connected to a movable contact unit (4), actuated by a centrally mounted between two disks (19,20) drive shaft (5), and concentrically on it is a hollow insulated shaft (10) connected to a movable contact assembly (9) connecting the large (6) and the small (8) auxiliary contact arcs, the main VDK (V) and the auxiliary VDK (V) having separate cams (14, 15), and the interaction between the two shafts (5, 10) takes place through a sector (16) and an arm (17), between which there is a free angular stroke. Single-phase power switch according to Claim 1, characterized in that the cam (14) for the main VDC (V) is mounted on the drive shaft (5) and the cam (15) for the auxiliary VDC (V ₂ ) is mounted on the hollow insulating shaft (10). Descriptions of issued patents for inventions № 02.2 / 28.02.2019 Single-phase power switch according to Claim 1, characterized in that the two cams (14, 15) are mounted on the drive shaft (5). Single-phase power switch according to claims 1, 2 and 3, characterized in that a shoulder with a buffer (33) is attached to the insulating shaft (10), limited in both end positions by an arc (34) with limiting elements (35) . Single-phase power switch according to claims 1,2,3 and 4, characterized in that the angle switching a consists of three functional steps, the first (a / 3) actuating only the main contact unit (4), in the second step (a / 3) - the main VDK (V) and in the third step (a / 3) - the auxiliary VDK (V ₂ ) and this sequence is preserved for all switches.