BG65908B1 - Power switch for step voltage regulator with vacuum arc chutes - Google Patents

Abstract

The power switch is built in a step regulator intended to switch under load the deviations of the power transformer regulating winding. Thus the operating transformer voltage gets regulated. The use of vacuum arc chutes (VAC) does not cause pollution of the insulating medium of the transformer, which may be either transformer oil or elegas (gas SF6). The commutation ability is increased. The power switch with VAC is interchangeable with the known power switch with arc extinction in oil. The power switch has two main VACs (1, 2) and one secondary VAC (3), which is in-series connected to a resistor (44) and a switching contact unit (21, 22, 23, 24, 25). The motion of the switching contact unit is performed by an arm (15) of a spring mechanism (14), such arm acting upon a ring (30) that contains a pin with a roll (32). At the end of the arm (15) motion, the roll overturns a fork (28) fastened at the lower end of an insulating shaft (27), which rotates the contact plates (25) of the switching contact unit. A slipping flywheel (20) mounted on a driving shaft (8) is used for the purpose of stabilizing the switching times and reliable additional switching.

Description

Technical field

The invention relates to a power switch for a stepped voltage regulator under load of power transformers. Vacuum damping chambers are used in it in order not to pollute the insulating medium in which it is submerged and to increase the switching capacity. It can be used both in oil transformers and in transformers with insulating medium elegas (SFe gas)

BACKGROUND OF THE INVENTION

A power switch with vacuum arc chambers (1) is known, comprising two main vacuum arc chambers and one auxiliary arc chamber connected in series with a resistor and a switching contact assembly. A single disconnector is provided in series with each main vacuum boom, providing increased insulation strength. The overall conclusion of the three vacuum choke chambers has a lever system that interacts with humps incorporating the vacuum choke chambers in a certain order. The humps are located on a spring-driven, battery-powered shaft. On the same shaft there is a disc with pins that jump-start the disconnectors and the switching contact assembly.

A disadvantage of the known power switch is that it is difficult to synchronize the opening and closing of vacuum arc chambers, high-speed disconnectors, and the high-speed switch contact unit, designed to provide the necessary times for extinguishing electric arcs. This impedes production and control and limits application.

Another disadvantage is that the power switch is not interchangeable with the power switch with butterfly throttling, which works on many sites. This does not allow the old switch to be removed and replaced with a new one, which has significant operational advantages.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a power switch for a step-by-step voltage regulator with vacuum arc chambers that is easy to manufacture and control and is interchangeable with a power switch with buttermilk in oil.

The problem is solved by a power switch with vacuum arc chambers, comprising two main vacuum arc chambers and one auxiliary vacuum arc chamber, connected in series with a resistor and a switching contact unit, a spring mechanism with centrally rotating pivot and rotary actuator wherein according to the invention the switching contact assembly for each phase is composed of two contact queues connected respectively to the supports of the two main vacuum quenchers chambers, an arcuate contact element secured by an insulating element to the support of the auxiliary vacuum extinguishing chamber and contact plates. The contact plates are clamped to the upper end of a vertical insulating shaft which has a fork at its lower end. Below the bottom of the power switch, a rotating ring is mounted at a certain angle, containing a pin with a roller that interacts with the end positions of the switch with the fork. There are also two pins on the ring, one for each of the two switching directions. In the final position, the rotating arm interacts with the corresponding pin, the ring rotates and the roller pin flips the fork and contact plates. This happens after the spring mechanism has made the power switch.

A sliding flywheel mounted on the drive shaft was used to achieve suitable switching times.

With a single-phase power switch, the resistors are located inside the insulation cylinder at the level of the vacuum damping chambers.

Advantage of the power switch for step regulator with vacuum arc

65908 Blind cameras according to the invention is that the switch contact assembly is actuated by slow motion immediately after the jump switch. This makes it easier to synchronize between the operation of vacuum blowers and high-speed disconnectors. This facilitates production and control. At the same time, in the steady state, the auxiliary vacuum extinguisher and the resistor are connected in parallel to the closed main vacuum extinguisher.

An additional advantage is the use of a sliding flywheel, which enables favorable combustion times and damping of electric arcs during switching.

Another advantage is that the power switch with vacuum blowing chambers is interchangeable with the many-object power switch with butterfly-throttling in operation. In this way replacements can be made, which will significantly increase the operational parameters.

Explanation of the annexed figures

An exemplary embodiment of the power switch with vacuum damping chambers according to the invention is shown in the accompanying figures, of which:

Figure 1 is a longitudinal section view of a single-phase power switch.

FIG. 2 is a top plan view of the power switch of FIG. 1.

3 is a bottom view of the power switch of FIG. 1.

Figure 4 is a longitudinal section of a three-phase power switch unified with the single-phase of Fig. 1.

Examples of carrying out the invention

The single-phase power switch (Fig. 1 and Fig. 2) has an odd vacuum damping chamber (VDK) 1 and an even vacuum (VDK) 2. Between them is an auxiliary VDK 3. The three VDKs are secured by supports 4 to an insulating plate 5. Through an insulating cylinder 6, the plate 5 is connected to the metal bottom 7 of the power switch. In the center of the metal bottom there is a drive shaft 8 with cam gear 9 for main VDK1 and 2 and cam drive 10 for auxiliary VDKZ. The three VDKs are closed and opened in a sequence by the action of the cam disks 9 and 10 on a mechanism composed of bearing 11, the D-shaped fork 12 and the rod 13.

The drive shaft 8 is swiveled (approximately 90 °) by a spring mechanism 14 that is secured between the arm 15 and the lever 16 coupled to the shaft8. The lever 16 is locked at the two end positions by lock 17 and a buffer 18 is provided to soften the impact at the end.

Springs 19 are provided to provide contact pressure to the VDK 19. In order to harmonize the switching times and to ensure safe shut-off, a flywheel 20 is fitted on the shaft8.

The switching contact assembly is composed of two contact queues 21 and 22 connected respectively to the two main VDK1 and 2, an arched contact element 23 secured by an insulating element 24 to the carrier 4 of the auxiliary VDKZ and movable contact plates 25 with contact springs 26. The contact plates 25 are secured to the upper end of a vertical insulating shaft 27, supported to the insulating plate 5 and the metal bottom 7. A fork 28 (Fig. 1 and Fig. 3) is mounted on the lower end of the insulating shaft 27. Below the bottom 7, a rotating ring 30 with two interacting with the arm 15, a pin 31. is mounted on the bottom 7 through the three rails 29. A pin with a roll 32 is mounted on the ring 30, which interacts with the fork 28. The two end positions of the ring 30 are fixed by its protrusion 33 and two stops 34.

The power switch is coupled in a known manner to an unshown oil pan bottom by an odd contact 35, an even contact 36, and a current contact 37. There is a known mechanism at the bottom of the oil pan that rotates the arm 15 through the tail 38.

The current connection between VDK1 and socket 35 is made by an odd disconnector 39 (Fig. 2 and FIG. 4) and the connection between VDK1 and socket 36 by an even disconnector 40. The disconnectors 39 and 40 are actuated alternately by pins 41 and 42, mounted to disk 43 coupled to drive shaft 8.

65908 Bl

In the space free of the contact system, at the VDK level, one or more current-limiting resistors 44 are mounted, fixed to the bottom 7 by means of an insulating plate 45. Figure 4 shows a three-phase power switch in which the three phases are like those of the single-phase one. FIG. 1 and are 120 ° apart from each other. Here, the resistors 44 attached to the insulating ring 46 are located above the contact system.

The operation of the single-phase or three-phase power switch according to the invention is as follows:

In the stationary position (Fig. 1 and Fig. 2), the main VDK1 is switched on and the auxiliary VDK3 and the other main VDK2 are open. The disconnector 39 is closed and connected in series with VDK1. The working current flows through this circuit. The switch 40 is open and provides a high insulation level. The contact plates 25 are connected to the contact tail 21 of VDK 1. In this way, the VDK and the resistor 44 connected in series therewith are connected in parallel to the VDK1.

In order to switch from VDK1 to VDK2, the mechanism shown at the bottom of the oil pan does not start, by means of the tail 38, to rotate clockwise (Fig. 3) the lever 15. The lever 16 is retained by the lock 17 and the spring mechanism 14 begins to rotate. stretches and accumulates energy. After a certain rotation (eg 120 °), the lock 17 releases the lever 16 and switches jumping. First, disconnect 40 is closed, and then the humps 9 and 10 sequentially include the VDK3, switch off the VDK1, include the VDK2 and switch off the VDK3. Finally, disconnector 39 opens. The arm 15 is rotated further and clockwise (Fig. 3) and the ring 30 is rotated by the pin 31. The roll pin 32 turns the fork 28 and through the insulating shaft 27 the contact plates 25 are connected to the tail 22 of VDK2. . Flywheel 20 slows down the movement at the beginning of the shift, and at the end - helps to secure the switch. Its movable parts slip on impact of the buffer 18 in the end position and reduce the dynamic load.

The reverse switching is done in the same way by turning the arm 15 counterclockwise (Fig. 3).

Claims (3)

Claims 1. Power switch for a voltage regulator with vacuum arc chambers, comprising two smooth vacuum arc chambers, one auxiliary vacuum arc chambers connected in series with a resistor and a switching contact unit, a centrally rotating spring-loaded mechanism command humps, characterized in that the switching contact assembly for each phase consists of two contact queues (21,22) connected respectively to the supports (4) of the two main vacuum damping chambers (1,2), arc contact element (23) secured by means of an insulating element (24) to the support (4) of the auxiliary vacuum damping chamber (3) and contact plates (25) held to a vertical insulating shaft (27) ) which at its lower end has a fork (28) functionally connected to a pin with a roller (32) located on a rotating ring (30), which is supported by the bottom (7), the rotating ring (30) having two pins (31). ) which are functionally connected to the end of the rotating arm (15) of the spring mechanism (14). Power switch according to claim 1, characterized in that a sliding flywheel (20) is arranged on the drive shaft (8) connected to the spring mechanism (14). Power switch according to Claims 1 and 2, characterized in that, in a single-phase embodiment, the resistors (44) are arranged inside the insulation cylinder (6) at the level of the vacuum blowing chambers (1, 2, 3).