BG67223B1 - On-load tap-changer column with laterally positioned preselector - Google Patents

Abstract

The on-load tap changer comprises a carrier head (1), an insulating cylinder (3) and a bottom (3). There is a fixed insulating cylinder inside (25), in which three single phase power switches are arranged in tiers for the three phases (x, y, z.). Around each phase there is an even current-carrying ring (28), an odd current-carrying ring (29) and an output current-carrying ring (30) that are connected in a definite sequence to fixed contact elements (45, 46, 47) via contact bridges - even (39) , odd (41) and current-carrying (40). These contact bridges are rotated periodically by vertical insulating shafts (35, 37) connected to a Geneva drive (17, 18, 19). In the carrier head (1) there is a spring-energy accumulator (8) and a drive system of toothed gears (91 10). The preselector consists of separate nodes for each phase, attached to the last of the even and odd fixed contacts. The contact system is positioned horizontally and provides both a pre-selector upender and an RF preselector.

Description

(54) STEP REGULATOR HA VOLTAGE COLUMN TYPE WITH SIDE LOCATOR

Field of technology

The invention relates to a three-phase step voltage regulator of column type, in which three single-phase power switches for the three phases are located one below the other in a column. The pre-selector doubles the control range of the power transformer in which the step controller is integrated. Power switches can be of the conventional type with oil arc quenching or with vacuum arc quenching chambers.

BACKGROUND OF THE INVENTION

A step voltage regulator is known from the so-called load voters [1]. It consists of a bearing head, an insulating cylinder and a bottom. Drives and a spring energy accumulator are located in the support head. The contact systems of the three phases are arranged in floors one below the other. They comprise fixed contact elements mounted in a circle on the inner surface of the insulating cylinder and roller movable contact elements attached to an insulating tube driven by the spring-energy accumulator. Current-limiting resistors are also mounted on the pipe. The pre-selector is located above the first phase.

The disadvantage of this step controller is that it has relatively low technical and operational parameters. The contact elements wear unevenly from the electric arcs. Revision and replacement of worn fixed contact elements is difficult. The supporting insulation pipe is subjected to radial forces and it is necessary for the three phases to be displaced at an angle to each other.

Another step regulator is also known [2], operating as a load selector. It has a similar construction, but two vacuum arc quenching chambers with movable contact elements and resistors are attached to the drive central insulation pipe. The fixed contact elements are also arranged in a circle and are mounted to the inner surface of the insulating cylinder. They do not wear out electrically, but are subjected to strong impacts from the movable contact elements during hopping.

The pre-selector is a laterally located pipe with contact sockets mounted in it one below the other.

The disadvantage of this step regulator is that it has a large diameter and nevertheless does not provide an adjustment range greater than ± 11 steps. Another disadvantage is that a more powerful spring-energy battery is needed due to the high resistance moments during switching, accompanied by the strong shocks noted above. Another disadvantage is that the drive system of the pre-selector performing vertical movement is complex.

Another concept of construction of a step regulator of column type is given in [3]. It works as a normal step controller with split dialing and power switching. Three single-phase power switches for the three phases are mounted one below the other in a centrally located insulating cylinder on the outer surface, to which movable contact rollers are attached. On the inner surface of the bearing insulating cylinder are mounted arcuate fixed contact elements, with

BG 67223 Bl which alternately contact the rollers. The centrally located insulating cylinder with power switches is rotated stepwise by a Maltese gear housed in a support head. A special gear differential mechanism is used to synchronize the operation of the Maltese gear with the spring-energy accumulator. The pre-selector for each phase consists of an insulating carrier with three linearly arranged fixed contact elements and a movable contact plate, moved vertically up and down by an insulating rail. The insulating supports are attached to the last even and odd contact elements, located one below the other.

The disadvantage of this step regulator is that it uses a complex spring energy accumulator and a gear differential mechanism. Another disadvantage is that the contact rollers have a front contact, which does not guarantee high electrodynamic stability and creates a radial load on the rotating central insulating cylinder. Therefore, the movable contact systems for the three phases must be offset at an angle.

It is also difficult to insert and remove the insulating cylinder with the power switches and the movable contact rollers in the oil tank. Another disadvantage is that due to the vertical movement of the movable part of the pre-selector, the drive mechanism is complicated.

A column-type step regulator is also known [4], in which the three single-phase power switches are mounted in a fixed insulating cylinder, which is built into an oil vessel with radially conducting current rings. The fixed contact elements are attached to segments of an insulating cylinder. The contact between them and the current-carrying rings is made by arcuate movable contact elements mounted on a vertical insulating shaft, which is driven by a combined Maltese gear located in the support head. Preselector not shown.

The disadvantage of this step regulator is that it is very complex and has large dimensions and weight.

Technical essence of the invention

The object of the invention is to provide a step voltage regulator of column type, which has a simple and compact construction with three single-phase power switches fixed in a central insulating cylinder. The Maltese gear should be in two variants, both single for single-shaft selected and double - for two-shaft selected. To have standard contact systems of choice, which do not create radial forces and have increased thermodynamic stability. The pre-selector shall be of separate identical nodes for each phase, which shall be attached to the last by number even and odd fixed contacts elements. The mechanisms located in the support head and synchronizing the operation of the spring-energy accumulator, the Maltese gear and the pre-selector should have a simple construction and take up little space. Ensure easy insertion of the inside with the power switches in the oil pan.

The problem is solved with a three-phase step voltage regulator of column type, containing an oil vessel consisting of a bearing head, an insulating cylinder and a bottom. Inside it there is another insulating cylinder, in which three single-phase power switches are located on the floor, and around it there are fixed and movable contact elements. In the bearing head are mounted a spring energy accumulator, Maltese

BG 67223 Bl gear and mechanisms for synchronizing their joint operation. A pre-selector with insulating and contact elements is mounted on the side of the oil tank.

According to the invention, the three single-phase power switches are arranged one below the other in an internal insulating cylinder which is fixed. This cylinder could be replaced by a cage of segments. For each phase, an evenly conductive ring, an odd conductive ring and a terminal conductive ring are arranged coaxially on the insulating cylinder. The connection between these rings and fixed contact elements mounted on the inner surface of the insulating cylinder of the oil pan is made by even contact bridges, odd contact bridges and current-carrying contact bridges mounted on vertical insulating shafts. These shafts are driven by Maltese wheels mounted on a metal cylinder mounted on a bearing flange.

A cylindrical bracket is mounted on the bearing flange, to which a gear wheel is mounted on the top, and a double gear for the Maltese wheels is mounted on the bottom. The gear and the double gear are connected by a clutch that has a certain free travel. The gear performs half a shift, driven by a parasitic gear from a worm gear connected to a worm gear, which performs one shift. The first gear is connected by a rod to a spring-loaded energy accumulator, charging it every half turn.

Maltese gears can be in two versions. The first has a Maltese wheel and has only one insulating shaft carrying the movable contact bridges. In this case, the fixed contact elements mounted on the inner surface of the main insulating cylinder are shaped like arcs. The two-Maltese version has two insulating shafts that are activated one after the other. In this case, the fixed contacts are normal and higher insulation parameters are provided.

Due to the different angles of rotation of the spring energy accumulator (approx. 90 °) and the shaft driving the power switches (in the range from 120 ° to 1 80 ° depending on the type of power switch), a gear is mounted on the bearing flange. Power switches can be of the conventional type with oil arc quenching, as well as those with vacuum arc quenching chambers.

The pre-selectors for each phase are the same in construction, but are separated from each other. They have insulating supports formed by a vertical plate attached to the last numbered fixed contact element and the last odd fixed fixed element located below it. In the middle of the plate there is a horizontally located arcuate insulating element, on which two fixed contact elements of the pre-selector are mounted. At the same horizontal level in the middle of the plate there is another fixed contact element with a terminal. The connection of these contact elements with one of the two contact elements located on the arc is made by a contact bridge carried by a vertical insulating shaft of the pre-selector. Alternatively, the insulation system may be assembled from several parts.

The kinematic chain for actuating this insulating shaft consists of a roller connected to an odd Maltese wheel, a two-position sector, a vertical shaft leading above the bearing flange a arm connected by a rod to a arm driving the pre-selector shaft.

BG 67223 Bl

The pre-selector can implement both a reversible version and a coarse-foot pre-selector. This is achieved by connecting different contact elements differently.

An advantage of the step voltage regulator of column type with lateral pre-selector is that it has a simple and rational design, providing small dimensions and high technical parameters. It is possible to use different variants of power switches and selectors. For example, for a smaller step controller with lower parameters, a conventional power switch with a single-shaft selector can be used, and for a large step controller with high parameters, a switch with vacuum arc suppression chambers and a two-shaft selector can be used.

Another advantage is that there is no radial effort from the voter's contacts, which requires some special measures to achieve stability. Butt contact, which reduces thermodynamic stability, is avoided. Another advantage is that the insertion and removal of the inner part is done without effort and risk of damage when performing these actions.

The advantage of the pre-selector is that separate units are used for each phase, which have a stable contact system at small overall dimensions. The actuation of the pre-selector is simpler and more stable because the vertical reciprocating motion is replaced by a rotary one.

Explanation of the attached figures

An exemplary embodiment of the three-phase column-type voltage regulator according to the invention is shown in the attached figures, of which:

Figure 1 - is a longitudinal section of a step voltage regulator.

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

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

Figure 4 - cross section of the selector and pre-selector in a single-shaft drive system.

Figure 5 - cross section of the selector and pre-selector in a two-shaft drive system.

Figure 6 is an enlarged longitudinal section through the support head of a two-shaft drive system.

Figure 7 is a top view of the Maltese gear and the pre-selector actuator with a two-shaft drive system.

Figure 8 is an enlarged longitudinal section through the support head of a single-shaft drive system.

Figure 9 is a top view of the Maltese gear and the pre-selector actuator in a single-shaft drive system.

Examples of the invention

The support structure of the step regulator consists of a support head 1, an insulating cylinder 2 and a bottom 3. The support head 1 comprises a housing 4, a support flange 5 and a cover 6. A known gearbox 7 with worm gear, digital pointer and end is mounted on the flange 5. mechanical lock. In the bearing head 1 there is a known spring energy accumulator 8 and a charging system of three gears 9, 10 and 11 (Fig. 2), 11 being driven by the gearbox 7. Gear 9 drives the spring-energy accumulator (PEA) 8 by means of a rod 12 at each switch. The shaft 13 of the gear 9 is mounted in a cylindrical carrier 14 (Fig. 6), which is mounted together with the PEA 8 on a bearing flange 15. To the lower part

BG 67223 Bl on a flange 15 is a clamped metal bearing sleeve 16. around which are mounted an even Maltese wheel 17 and an odd Maltese wheel 18. This is in the case of a two-shaft selector variant. With a single-shaft selector, there is only one Maltese wheel (Fig. 8). The two Maltese wheels 17 and 18 are rotated alternately in one step by a double translation 19, the shaft 20 of which is also mounted in the carrier 14. Between the shafts 13 and 20 there is a known clutch 21 with a freewheel at a certain angle. The PEA rotates a gear 22, which is engaged with a smaller gear 23. This is necessary because the angles of rotation of the PEA 8 and the shaft 24 performing the switching of the three single-phase power switches x, y and z are different. Power switches can be either conventional type with oil arc quenching or vacuum arc quenching chambers.

The three power switches are mounted inside a fixed insulating cylinder 25 having an upper flange 26 attached to a support sleeve 16 and a lower flange 27. Coaxially around the cylinder 25 are mounted for each phase an even current ring 28, an odd current ring 29 and an output ring 30. The switching of the power switches is done by a shaft 24 through a main insulating shaft 31 and intermediate shafts 32. which are metal when connected in a star center and insulating in isolated phases. If necessary, a flywheel can also be used 33.

An arm 34 is connected to the even Maltese wheel 17, which actuates an even vertical insulating shaft 35 shaped like a rail or tube. Respectively, an arm 36 is connected to the odd Maltese wheel 18, which actuates an odd vertical insulating shaft 37. The odd Maltese wheel 18 has a roller 38 which actuates the pre-selector. The even insulating shaft 35 carries even contact bridges 39 and terminal contact bridges 40, and the odd insulating shaft 37 carries odd contact bridges 41 and terminal contact bridges 40. The lower ends of the two insulating shafts 35 and 37 are mounted by arms 42 and 43 to axis 44. , attached to the lower flange 27. On the inner surface of the insulating cylinder, for each phase and in a circle, even 45 and odd 46 fixed contact elements and terminal contact elements 47 are arranged. There are two variants for the type of these fixed contact elements.

In the case of a two-shaft selector (Figures 5. 6, 7), the fixed contact elements 45 and 46 are of normal width. In this case, the double translation 19 has two rollers 48 and 49 and the rotation of the two Maltese wheels 17 and 18 takes place at a double angle. In the case of ten contact elements at 72 °. In this variant, the insertion and removal of the power switches and movable contact bridges carried by the flange 15 is easy. An adjustment range of ± 17 steps can be easily achieved.

In the case of a single-shaft selector (Figures 4, 8, 9), the fixed contact elements are shaped like arcs 50. The double translation 19 has one roller 51. The rotation is one step, in this case 36 °. The insertion and removal of the central part can be facilitated if it is possible for the two even and odd contact bridges 52 and 53 to rotate in two positions of 90 ° - tangentially during insertion and removal and then radially in the operating position.

The pre-selector is actuated by the following kinematic circuit (Figures 3, 6, 7): The roller 38 acts on the two-position sector 54 mounted on the shaft bearing 56 in the sleeve 55. It transmits the movement over the flange 15 and arm 57 via rod 58, rotates arm 59 , mounted on a shaft 60. which is mounted in a sleeve 61 mounted on a housing 4. The shaft 60 is sealed against the weight by seals 62 and has an arm 63,

BG 67223 Bl which carries an insulating vertical shaft of the preselector 64. In its lower part the insulating shaft 64 has an arm 65 which is mounted on a bottom 3.

The preselector represents three separate sectors for each phase. Each sector comprises an insulating carrier 66, injection molded from plastic or molded from epoxy compound and formed by a vertical plate 67 and an arcuate carrier on which the two fixed contacts of the preselector 68 and 69 are mounted. fixed contact elements. In the middle of the plate there is a fixed contact element 70 with a terminal 71. A movable contact bridge 72 is mounted on the insulating shaft 64 of the pre-selector and makes a connection between the contact element 70 and the corresponding contact element 68 or 69.

The following variants are realized with this preselector: When connecting contact 70 with contact 10, a reversal with one or three middle positions is realized. When connecting 70 to contact 9, a rough step with three middle positions is achieved, and when connecting 70 with an external connection, a rough step with one middle position is achieved.

The operation of the step controller according to the invention is as follows: The gearbox 7 is actuated by an undisplaced motor drive and rotates a gear 11 at one switching speed. By bearing shaft 60, the parasitic gear 10, gear 9 is rotated half a turn for switching, pulls the PEA and rotates the respective Maltese wheel 17 or 18 by means of the double translation 19. The movable contact bridges are rotated by the respective vertical insulating shaft 35 or 37 and the next deviation from the control winding of the transformer is selected. This is followed by the release of the three single-phase power switches x, y, z. During the switching from the ninth to the first step, the roller 38 activates the kinematic circuit described above and the preselector is switched.

Claims (8)

1. Step-type column-type voltage regulator with a side-mounted preselector comprising an oil vessel consisting of a support head, an insulating cylinder and a bottom, with three single-phase power switches located on the floor in another internal insulation cylinder, movable and fixed contact elements -energy accumulator and a system of gears housed in the support head, each phase having a laterally located pre-selector with contact elements, characterized in that the three single-phase power switches (x, y, z) are located on the floor inside a fixed insulating cylinder ( 25) or in a cage of segments, coaxially around the cylinder (25) for each phase are arranged evenly conductive ring (28), odd conductive ring (29) and terminal conductive ring (30), the connection between these rings and mounted on the inner surface of the insulating cylinder (2) of the oil tank fixed contact elements (45, 46, 47) is made by even and contact bridges (39), odd contact bridges (41) and current-carrying contact bridges (40) mounted on vertical insulating shafts (35, 37), driven by Maltese wheels (17, 1 8), mounted on a metal bearing sleeve (16 ) mounted to a support flange (15). Step voltage regulator according to Claim 1, characterized in that a cylindrical support (14) is mounted on the support flange (15). to which a gear wheel (9) is mounted at the top and at the bottom BG 67223 Bl - double translation (19) for Maltese wheels (17. 18). connected by a coupling (21) with a certain free travel. as the gear (9) rotating half a turn and is driven by a parasitic gear (10) by a gear (11) connected to a worm gear (7) and making one shift and a gear (9) through a rod (12) charges a spring energy accumulator (8) Step voltage regulator according to claims 1 and 2, characterized in that the Maltese gears can be in two variants - with a Maltese wheel (18) and a single-shaft selector, in which the fixed contact elements (50) are designed as arcs or - with two Maltese wheels (17, 18) and a two-shaft selector, in which the fixed contact elements (45, 46) are of normal width. Step voltage regulator according to claims 1, 2 and 3. characterized in that due to the different angles of rotation of the spring-energy accumulator (8) and the shaft (24) of the power switches (x, y, z) is intended gear (22-23). Step voltage regulator according to claims 1, 2, 3 and 4, characterized in that the power switches can be both conventional with oil arc quenching and those with vacuum arc quenching chambers with the same design of the entire step regulator. Step voltage regulator according to Claims 1 to 5, characterized in that the pre-selector for each phase is made of insulating material, cast of epoxy compound or injected of glass-filled polyamide and consists of a vertical plate (67) fixed in this case. to the tenth contact and the ninth contact located below it, an arcuate carrier (66) connected to the plate (67) mainly in its middle and mounted horizontally, with a contact element (70) with a terminal (71) mounted in the middle of the plate, and on the arcuate part at the same level are located two fixed contact elements (68, 69), the connection between the contact elements (70) and alternatively - with one of the contact elements (68, 69) is made by a contact bridge (72) carried by vertical isolating shaft (64) of the preselector. Step voltage regulator according to Claims 1 to 6, characterized in that the kinematic circuit for actuating the vertical insulating shaft (64) is composed of a roller (38). two-position sector (54), vertical shaft (56), arm (57), bar (58) and arm (59). connected to a shaft (60) bearing a arm (63) rotating the vertical insulating shaft (64) of the pre-selector. Step voltage regulator according to Claim 6., characterized in that a reversing pre-selector is provided. contact elements (70 and 10) are connected, for realization of a pre-selector for rough step with three middle positions - (70 and 9) and for realization of pre-selector for rough step with one middle position contact element (70) is connected with an external conductor.