BG63835B1 - Selector switch - Google Patents

Abstract

The selector is intended for step transformers for continuous switching between the deviations of the control coil. For each phase in the horizontal plane, fixed contacts are mounted inside the cylinder of insulating material (1). Inside the cylinder (1) there is a rotary switch shaft (2) having a contact carrier (3) for each switched phase, which is pivotally mounted and two vacuum circuit breakers are mounted vertically on it.

Description

(54) COMMODITY SELECTED

Technical field

The invention relates to a load selector for step transformers.

BACKGROUND OF THE INVENTION

Load switches for transformers serve to switch the deviations of the regulating windings of these transformers under load and thus expediently equalize the voltage deviations.

Freight voters are less expensive to manufacture and install because of the lack of a normal disconnect between the voter and the power switch.

In the process of switching, various contact electric arcs appear in the load selector.

DE 3 833 126 C2 describes a load selector in which, in each switching phase, two mechanical switching contacts are provided on one common contact carrier, which are simultaneously movable, capable of displacement, and which in succession to each of the two moving mechanical switches the socket is provided with a vacuum circuit breaker mounted on the socket.

The mechanical selector contacts, which can be displaced by the fixed contacts of the load selector, are mounted in a concentric circle in the cylinder wall of insulating material.

Vacuum switches are mounted horizontally on the contact carrier and are operated or respectively. actuate by means of a cam guide rail mounted on an additional concentric circle, located axially between the fixed contact circle and an additional contact ring.

By horizontally lying the vacuum switch on a common contact carrier, on the one hand, an unwanted large diameter of the insulation cylinder and thus of the load selector is obtained.

Vacuum switches, depending on their switching power, have certain minimum dimensions, in particular a considerable length extension. In the longitudinal direction, the actuating slider also extends outward from the vacuum switch. Obviously, the common contact carrier should have a radial extension dictated by the size of the vacuum switch and the actuator, which together determine the diameter of the load selector.

Based on these common dimension problems, the horizontal mounting of the vacuum circuit breakers, according to the prior art, implies that when the load selector is filled with oil along the upper bend of the bellows seal of the vacuum circuit breaker, air is not expelled completely. For this reason, the actuation of the vacuum circuit breaker results in an uneven load on the corresponding bellows seal, and there is a danger that it may rupture. The presence of residual air in the area of the bellows seal of the vacuum circuit breaker when lying down can only be avoided by filling the load selector under vacuum. However, filling in a vacuum on-site, for example after checks have been completed, cannot or cannot be carried out at very high costs.

In addition, it should be borne in mind that the payload selector generally has a large axial longitudinal extension, a significant structural height in the flow. Fixed stepping contacts of the individual switching phases, which are arranged one above the other in a circular fashion, means for actuating the rotary switch shaft inside the load selector, which carry a contact carrier for each phase in the load switch head, and means for bearing this shift shaft at the bottom of the load selector also needs space, so that overall the load selector has a considerable longitudinal extension. As a consequence, the switch shaft is also quite long.

Such switch shafts, which are typically made of GFK or other insulating material, are also known as metal switch shafts.

The contact supports of the known load selector are secured by mounting screws to the shift shaft.

DE 4 414 941 C1 describes another rigid attachment of a contact carrier to a switch shaft by means of a terminal flange.

Due to tolerances, different thermal expansion of the oil pan and circuit breaker, bends, etc., known loads may cause problems in the mutual clearance of the structural elements located on individual contact carriers, especially vacuum switches, with circular actuators. , in particular because the vacuum lever actuator lever has only a relatively small linear actuator stroke.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a load selector of the appropriate type, which forms a space-saving device for the vacuum circuit breakers and their safe and reliable actuation under all operating conditions.

The problem is solved by a freight selector with the features of the first patent claim.

The dependent claims relate to particularly preferred other embodiments of the invention.

In the load selector according to the invention, the vacuum switches are mounted on a contact carrier. The contact carrier has sliding contacts that guide straight through the rollers into the withdrawal ring. In this discharge ring, the tubular vacuum circuit breakers are controlled by humps.

Knife sliding contacts, which are mounted in the contact carrier, draw current through the deflection.

Additional knife sliding contacts are also possible in the contact carrier for guidance.

According to another feature of the invention, the contact bearers are mounted wines movably on the switch shaft.

The advantage of the load selector according to the invention, in addition to its small size, is that all the forces for actuating the vacuum switching cells, as well as the contact forces through the discharge ring and the fixed contacts, are supported axially in a stable oil pan. This avoids radial loading of the circuit breaker column, in particular its bending, and thus changes the timing of the control of the vacuum switching cells and the reduction of the contact forces. By means of the rotary carrier, respectively. Bearing with the possibility of displacement of the contact beams, which is driven axially through the withdrawal ring, the switching process is also achieved with large displacements by tolerances and different thermal extensions of the oil pan and the breaker column.

Explanations of the annexed figures

The invention is illustrated by the accompanying figures, of which:

Figure 1 is a first exemplary embodiment of a load selector according to the invention in partial cross-sectional view;

Figure 2 is a section of a contact carrier of this cargo voter in section, seen from above;

Figure 3 is a second exemplary embodiment of a load selector according to the invention in partial sectional view, sectional view;

FIG. 4 is a schematic representation of a load switch based on the switch according to the invention; FIG.

Figure 5 shows a modified such switch;

Figure 6 is a typical switching sequence of a cargo voter.

Examples of carrying out the invention

The load selector shown in Figure 1 shows an exemplary embodiment of the invention with rotatable bearing 2 on pivot carrier 3 and rotatably mounted vacuum switch cells 27, 28.

The load selector consists of a cylinder of insulating material 1, a switch shaft 2, preferably of insulating material, mounted centrally and longitudinally extending through the cylinder of insulating material 1. The switch shaft 2 can be rotated in a known manner. This is usually done by a Maltese drive which is not shown in the figures. Also, a schematic representation of the bearing of the switch shaft 2 to the bottom of the cylinder is made of insulating material 1.

The switch shaft 2 carries in each plane, which is actuated by the fixed stepping contacts 16, which are explained below in more detail, the contact carrier 3, which is supported by rotation in the bearing support on the switch shaft 2. The bearing support 4 is fixed to switch shaft 2 with bolts 4.1, 4.2.

The contact carrier 3 consists of a bearing part 5, a bearing housing 6 and a contact structure 7. The individual structural details of the contact carrier 3 are connected to each other by bolts 8, 9. The contact structure 7 consists of an upper contact body 10 and a lower contact body 11. The two parts are connected to each other by other screws 12. The contact structure can also be easily constructed as a monolithic. The bearing portion 5 has a bearing portion 13 into which a bolt 14 is inserted which connects to the bearing support 4 and thereby permits rotation. The position of the bolt 14 is secured by a cross pin 15.

In this way, the overall contact carrier 3 as a complete structural group can be rotated about the bolt 14 and thus with respect to the fixed switch shaft 2.

In the cylinder wall of insulating material 1, for each switching phase, always in a separate plane, fixed step contacts 16 are mounted, which are electrically connected to the deviations of the control coil of the step transformer to be switched. The fixed contacts 16 can be switched through the respective contacts 17, 18. These contacts 17, 18 are mounted on the contact carrier horizontally side by side, so that when the switch shaft 2 and thereby the contact carrier 3 are rotated, one of contacts 17, 18 reach the adjacent new fixed contact 16 before the other of these contacts leaves the previous fixed fixed contact. In this case, one contact 17 acts as a switch contact and the other contact 18 acts as an auxiliary contact.

Figure 2 shows the device of the two contacts 17, 18 above, side by side on the contact carrier 3 and interacting with the respective fixed step contacts 16. In the embodiment shown in Figure 2, the act acting as a switch contact 17, for reasons of possible double current capability load is made of two electrically connected parts 17.a and 17.b. Each of the contacts 17, 18 consists of an upper contact portion 17.1, 18.1, and respectively a lower contact portion 17.2,18.2. In the embodiment of FIG. 2, a variant embodiment of the switch contact 17 is made up of four parts in total, namely two upper contact parts 17.1a and 17.1b, as well as two lower contact parts 17.2a and 17.2c. This dual embodiment of the switch actuator 17 is appropriate for various embodiments, however, it is not necessary for the invention. Both the upper contact parts 17.1, 18.1 and the lower contact parts 17.2, 18.2 of each of the two contacts 17, 18 are always bearable with the possibility of rotation about different axes of rotation 19, 20, 21, 22 in the contact device. They are pressed together by the springs 23, 24, 25, 26 in the direction of the fixed contacts 16 between them.

The respective contact part 17.1, 18.1, as well as the corresponding always other contact part 17.2, 18.2, press with a certain contact force on both sides on the respective fixed contact included 16. In the bearing described above, these separate centers of rotation 19, 20, 21, 22 are possible overlap on fixed step contacts 16. In figures 1 and 2, only in the direction of view, front, respectively.

from above, the contact parts, rotary axes and springs can be seen.

In addition, two vacuum switch cells are secured to each contact carrier 3 via the upper and lower fixing brackets 29, 30, 31, 32 such that the bellows seal 33, 34 as well as the actuator slider 35, 36 of the vacuum switch cells 27, 28 stretch upwards. Also, the structural parts just described in FIG. 1 show only those that lie anteriorly to the gaze direction. For actuation of the actuating sliders 35, 36 of the vacuum switching cells 27, 28 serve two levers 37, 38, which always have at their free end a roller finger 41, 42 with a control roller 39, 40. At their other free end, they act on the previously described actuating sliders 35, 36. The two levers 37, 38 are rotated in rotation centers 43, 44. A common center of rotation may also be provided. The control rolls 39, 40 of the two levers 37, 38 in turn correspond to a control ring 45 having an upper control circuit 46 as well as a lower control circuit 47. The control ring 45 extends radially to the inner wall of the cylinder of insulating material 1 It can be seen from Figure 1 that the first control roll 39 corresponds to the lower control loop, more precisely crawls on it, and thus the second control roll 40 passes on the upper control circuit 46. The two control circuits 46, 47 serve to actuate the vacuum. the smart switching cells 27, 28 by rotating the corresponding lever 37, 38 by rotating about its center of rotation 43, 44 by walking the respective control roll 39, 40 on one contour, thereby activating the respective actuating slider 35, 36 of the vacuum switching cell 27 , 28.

In addition, on the inside of the cylinder of insulating material 1 there is an outlet contact ring 48, which has an outwardly joining member 49 and serves as a load deflection. The control ring 45 and the discharge contact ring 48 can be combined in a particularly simple manner into a single structural element of conductive material, as shown in figure 1. The discharge contact ring 48, in turn, again corresponds to a mechanical discharge contact 50, which is mounted on contact carrier 3 and, quite similarly, as described contacts 17, 18, consists of an upper discharge contact portion 50.1 and a lower contact portion 50.2. These two lead-off contact members 50.1, 50.2 are similarly bearing with the possibility of rotation about other rotation centers 53, 54 and are pressed together by other springs 51, 52, so that they engage the discharge contact ring 48 at a specified contact pressure.

Finally, the contact carrier 3 has two more rolls 55, 56 which are double-sided on the withdrawal contact ring 48, thereby guiding the entire contact carrier 3. By means of the construction described, it is possible to compensate for any tolerances of any kind and to compensate for particular curvature. the long switch shaft. The contact carrier 3 mounted around the pivot shaft 2 is rotatably guided in each case via the withdrawal contact ring 48, so that despite the tolerances described, precise control of the control rollers 39, 40 and actuation of the vacuum switch cells 27, 28 are ensured, their small actuation stroke.

Figure 3 shows another exemplary embodiment of a load selector according to the invention, wherein the contact carrier 103 is not mounted rotatably but rather longitudinally displaced.

Inside the cylinder of insulating material 101 there is also a centrally mounted switch shaft 102 which carries a longitudinally displaced contact carrier 103. The longitudinal displacement capability is achieved by guide 104. Two vacuum switching cells are mounted vertically, with only the front vacuum switch represented. cell 105. In each plane there are also fixed contacts 106 circularly mounted in the cylinder wall of insulating material 101, which are again commuted by means of a switch contact and by an auxiliary horse act as the figure are shown only an upper contact part 107.1 and the associated lower contact part 107.2. Similarly, again inside the cylinder of insulating material there is an outlet contact ring 108 which is covered by an outlet contact which consists of an upper contact portion 109.1 and a lower contact portion 109.2. In this case, guiding of the complete contact carrier is performed by a roll 110, which rolls in the contour of the withdrawal contact ring 108. The control of the vacuum switching cells is again performed by two levers 115, 116, which have control rolls 113 at their free ends. 114, which circumvent the lower control circuit 111, respectively. upper control loop, thereby activating the actuator slider of the vacuum switching cells, with only the actuating slider 117 being presented, which in the gaze direction is for the forward vacuum switching cell 105.

Figure 4 is a schematic representation of a switch that is implemented with a load selector according to the invention. The electrical connections between the contacts 17, 18 to the vacuum switching cells 27, 28 and from there again to the outlet contact 50, and thus to the outlet contact ring 48, are not shown in Figure 1, which corresponds to this image.

Figure 5 shows a switch in which, as shown in Figure 2, the switch contact 17 consists of side-by-side contact parts 17a, 17b. In Figure 2, also corresponding to this image, the electrical connections are only guessed. The principle of operation does not differ, in the same way that the switching process according to Figure 4 and also according to Figure 5 realizes the same switching process.

An exemplary realized switching process is shown in Figure 6. The load selector is represented by different switching steps as described in EP 0 160 125. The inter-center distance between the fixed step contact in the main bend and the two fixed step contacts adjacent thereto is greater than the inter-center distance between the other fixed step contacts. This also allows the load selector to be integrated into transformers with higher rated voltages. In this way high impulse voltage can be achieved. This post also discloses suitable fixed contacts for such a freight voter, which are performed differently.

Nevertheless, a particular advantage is that the fixed contacts 16 are not curved as in the prior art, more precisely parallel to the bend of the insulating cylinder 1, but are straight as shown in FIG. 2. While, according to the prior art, the above, or lower contact parts 17.1, 18.1; 17.2, 18.2, constantly passing over the same working surface of the fixed contacts 16 according to the invention, constantly passing other points on the upper surface of the fixed contact 16, reducing its wear.

Claims (6)

Claims 1. Load selector for step transformers for continuous switching between the deviations of an adjustable coil of a step transformer, wherein the load selector has a cylinder of insulating material as a housing, in which a circularly circularly mounted inside the cylinder of insulating material step contacts which are electrically connected to the deflections, and in the center of the cylinder of insulating material there is a rotating switch shaft, which has for each horizontal equilibrium of the fixed contacts also a rotating contact carrier, wherein each of the contact carriers has at least two mechanical contacts that can contact the fixed contacts on the respective horizontal plane, and at least one of the contacts on each contact carrier is connected directly to the first vacuum a switching cell and at least one second of the contacts on each contact carrier is electrically connected to a second vacuum switching cell by means of an intermediate switch resistor, and always the other side of the two The vacuum switching cells on each contact carrier are electrically connected to a load deflection, characterized in that all contact nose (5) (3) of the switch shaft (2) is movable independently of each other and always the two vacuum switching cells (27 , 28) are mounted vertically on the respective contact carrier (3) so that their actuating slider (35, 36) extends substantially in the axial direction. Load selector according to claim 1, characterized in that each contact carrier (3) is pivotally mounted with 15 rotatable pivots about the center of rotation of the switch shaft (2). Load selector according to claim 1, characterized in that each contact carrier (103) is mounted pivotally on the shift shaft with the possibility of longitudinal displacement. Load selector according to one of Claims 1 or 2, characterized in that each of the contacts (17, 18) consists of at least one upper contact portion (17.1, 18.1) and at least one lower contact portion (17.2) , 18.2) and each contact portion (17.1, 18.1; 17.2, 18.2) is pressed together by the force of at least one spring (23, 30 24, 25, 26) such that when a fixed contact (16 is engaged) ) it is mechanically bilateral and contacts electrically. Load selector according to one of claims 1 to 4, characterized in that the fixed contacts (16) inside the cylinder of insulating material (1) have an extension that is different from the inner contour of the cylinder of insulating material (1) ) and in particular it is linear. Load selector according to one of Claims 1, 2, 4 or 5, characterized in that in the inner wall of the cylinder of insulating material (1) for each switching phase and thus for each horizontal plane of the fixed contacts (16) a corresponding control ring (45) is mounted, which has an upper control circuit (46) and a lower control circuit (47), and a lever (37) is mounted on each contact carrier (3) for each of the two vacuum switching cells (27, 28). , 38), mounted around a rotary axis (43, 44), with each lever (37, 38) always acting with one of twist two free ends on one actuator slider (35, 36) of one vacuum switching cell (27, 28) and with its other free end always pass on one of the control circuits such that, regardless of the spatial shape of the respective control circuit (46, 47) can activate the respective vacuum switching cell (27, 28).