EP1609162B1 - Multipoint switch - Google Patents

Abstract

The invention relates to a multipoint switch for continuously switching different coil branches of a step-down transformer. According to said invention, at least one torque motor associated to various drive configurations carries out different driving functions for individual groups, thereby substituting a conventional motor.

Description

The invention relates to a tap changer for uninterrupted switching between different winding taps of a control transformer.

Tap changers have been known devices for voltage regulation and ensuring a high quality of electrical energy for decades. Their basic mode of operation allows them to be subdivided into resistance quick switches and reactor switches.

The principle of all resistance quick switches goes back to the German Reich Patent No. 474 613, issued in 1929, which describes for the first time the principle of sudden, uninterrupted switching between different winding taps by means of short-circuited overshoot resistors. Tap changers based on this principle are known in numerous embodiments. A typical representative is the type "M" described in the company publication "Step switch type M inspection instructions or in the company publication" Step switch types M and MS. "This on-load tap changer has a tap selector for the loadless preselection of the winding tapping to which it is to be switched to. The operation of this on-load tap-changer is carried out by a motor drive with an electric motor, which, when put into operation, puts it on the one hand the fine selector and possibly a preselector continuously On the other hand, the motor drive sits laterally outside of the transformer, and the linkage, angle drive, gear stages and mechanical Geneva gearbox turn the energy into a tap-changer Itet. Has the energy storage reaches its end position, d. H. when fully raised, its hitherto fixed detent is released, and it makes a sudden movement with which it actuates the diverter switch. In Figure 1, the drive trains of this known on-load tap-changer are shown schematically. In Figure 2, a modified such on-load tap-changer is shown, which has a multiple coarse selector instead of a conventional preselector; this arrangement is also known to the person skilled in the art.

Another on-load tap-changer is described in the company publication "tap-changer type V - inspection instructions" or in the company publication "tap-changer type V" of the applicant. In this designed as a load selector type "V" are the preselection of the respective winding tap to be switched to, and the components for this subsequent switching structurally combined. Here, too, a motor drive with the above-described spatial arrangement is provided, which initially raises the energy storage. After its complete lift and subsequent triggering a rotatable switching shaft is actuated, the fast and uninterrupted by one on an adjacent other fixed contact, the each electrically connected to a winding tap, switches. A typical gear train of such a known load selector is shown schematically in FIG.

A tap changer of the type of reactor switch is z. B. from DE-PS 40 11 019 and DE-PS 41 26 824 and the company publication "Load Tap Changer Type RMV-I" of Reinhausen Manufacturing Inc., Alamo, Tennessee, USA known. They have two load branches preselectable by a tap selector, between which a switch, in this case a vacuum switch cell, is arranged in each phase to be switched. Each vacuum switching cell can be bridged by a bypass contact, which in turn connects at least one of the two load branches to the load discharge. The actuation of the vacuum switching cells is carried out by a respective energy storage, which is wound up by the movement of a drive shaft. For each phase to be switched, a double-sided cam is spatially arranged between the bypass contact and the energy storage, which is rotated by the drive shaft at each switching step by 180 degrees. On the side facing the bypass contact side of the double-sided cam there is a groove for controlling the bypass contact and on the other side another groove for controlling the vacuum switching cells driving force accumulator. The control of the force accumulator is such that it is tensioned once each switching step and then triggered and thereby actuates the vacuum switching cells. The operation of this tap changer is done by a motor drive with an electric motor, which, it is set at an intended switching in operation, on the one hand, the selector contacts continuously actuated and on the other hand via the cam described both the bypass contact also continuously actuated and raises the described energy storage. Has the energy storage reaches its end position, d. H. when fully raised, its hitherto fixed detent is released, and it makes a sudden movement with which it actuates the diverter switch. In Figure 7, the drive trains of this known tap changer are shown schematically.

Another tap-changer of the type of reactor switch is already known from DE-PS 197 43 864, in which, incidentally, the functional differences between reactor switches on the one hand and resistance snap-action switches are also shown in detail. In this known tap changer fixed selector contacts are provided in a housing for each phase, which can be connected by two movable selector contacts, further preselector contacts are provided for each phase. In turn, bypass contacts are arranged for each phase, and in each case a vacuum switching cell can be actuated by means of a force accumulator. In a separate lateral housing part a single drive mechanism for actuating all movable contacts and all vacuum switching cells is arranged in the corresponding switching sequence, said single drive acts by means extending through the housing insulating waves on the individual components. A typical gear train of this known tap changer is shown in FIG.

In the known tap changers, the drive is effected by an electric motor drive. Such a drive is described for example in WO 98/38661. In such a known motor drive all mechanical and electrical components that are required to drive the tap changer, united. Important mechanical assemblies are the load gear and the control gear. The load gearbox directly actuates the tap changer; It has a correspondingly dimensioned electric motor. The control gear includes a cam which rotates one full turn each time the tap changer is changed over. The cam disk in turn has a plurality of switching cams for the mechanical actuation of numerous cam switches or cam-actuated contacts. The control gear further includes means for displaying the tap position or the switching step. The electrical components in the motor drive include different circuits. Thus, there is a motor circuit through which the terminals of the electric drive motor via motor contactors, brake contactors and other switching means are connected to the power supply line. Furthermore, a control circuit and various signaling circuits and trip circuits for a motor protection switch are available. The control of the motor drive itself takes place according to the principle of stepping, d. H. an adjustment by a switching step is initiated by a one-time control pulse and then inevitably completed; the output shaft of the motor drive, which is coupled to a drive shaft of the tap changer, doing so in advance a precisely defined number of revolutions. Furthermore, the known motor drive, in addition to other safety devices, also a continuous protection device, which prevents the failure of the described step control of the motor drive passes through to the end position.

• Erzeugung eines Rotationsdrehmomentes mit nachfolgender Umsetzung in eine Bewegung für den Stufenwähler
• Übertragung sowie Über/Untersetzung des Drehmomentes
• Aufzug eines Kraftspeichers
• Umwandlung einer kontinuierlichen Bewegung in eine Schrittbewegung
• Fixierung des Schaltelementes nach vollzogenem Schaltschritt
• Stellungsmeldung
• mechanische Endanschlagsfunktion.

The known motor drive described has to fulfill a whole series of functions together with the downstream Geneva transmission in the tap-changer of the type of resistance rapid-action switch:

• Generation of a rotational torque with subsequent conversion into a movement for the tap selector
• Transmission and over / reduction of the torque
• Elevator of a power storage
• Conversion of a continuous movement into a step movement
• Fixierung of the switching element after completed switching step
• position feedback
• mechanical limit stop function.

Overall, both conventional motor drive and downstream gear are complicated in construction, expensive to manufacture, as necessarily highly accurate, and together with the energy storage usually represent the most complex part of the entire tap changer.

• Erzeugung eines Rotationsdrehmomentes mit nachfolgender Umsetzung in eine Bewegung für den Feinwähler sowie, getrennt davon, den Vorwähler
• Betätigung der Bypasskontakte
• Aufzug eines Kraftspeichers zur nachfolgenden Betätigung der Vakuumschaltzellen
• Stellungsmeldung
• mechanische Endanschlagsfunktion.

Insgesamt sind auch hierbei sowohl herkömmlicher Motorantrieb als auch nachgelagertes Getriebe kompliziert im Aufbau, teuer in der Fertigung, da notwendigerweise hochgenau, und sie stellen gemeinsam mit dem Kraftspeicher üblicherweise den aufwändigsten Teil des gesamten Stufenschalters dar.In a tap changer of the type of reactor switch, the known motor drive described together with the downstream transmission, in particular the Geneva drive and a Hebelumlenkgetriebe to fulfill the following functions in tap changer:

• Generation of a rotational torque with subsequent conversion into a movement for the fine selector and, separately, the selection
• Actuation of the bypass contacts
• Elevator of an energy storage device for subsequent actuation of the vacuum switching cells
• position feedback
• mechanical limit stop function.

Overall, here also both conventional motor drive and downstream gear are complicated in construction, expensive to manufacture, because necessarily highly accurate, and together with the power storage they usually represent the most complex part of the entire tap changer.

The object of the invention is to simplify the basic structure of tap changers, as it has been established for decades and solidified in the prior art, drastically.

This object is achieved by a tap changer with the features of the independent claims 1 and 6 or 11; the dependent claims relate to advantageous possible developments and modifications of the invention.

The invention is based on the general inventive idea of using at least one known per se torque motor as part of the drive train or strand of a tap changer.

Such torque motors are known, for example, from the company publication "Brushless Torque Motors" from ETEL. Such a known torque motor works on the same physical basis as a linear drive, except that the here lying flat stator is wound into a circle. A torque motor is therefore a high torque optimized servo drive; Modern versions are 3-phase brushless synchronous motors with permanent excitation. They are currently used in the machine tool industry. It has not yet been attempted to implement them in tap changer or to make it usable in principle for the drive of a tap changer.

Although there have been in the past described in DD Patent 58,131 from 1967 attempt to leave the conventional drive concept of a tap changer, as described above. It was a solution in which a tap selector of so many hydraulically actuated individual drive modules is formed as steps are provided so that arbitrarily between individual winding taps - not only between neighboring - could be switched. However, this hydraulic solution is because of the high functional risk, z. As the risk of aging of the supplying lines and seals, not realized.

For switching devices in general, various other drive mechanisms have been proposed. For example, EP 996 135 relates to a magnetic traveling-field drive for a switching device, WO 99/60591 and WO 00/05735 describe drives in the manner of a stepping motor for switching devices. These solutions are not readily applicable to tap changers, as they do not allow sudden movements and are a total problem for the realization of dynamic processes, even at low temperatures.

Finally, in WO 01/06528 still a controlled drive for a switching device has been proposed, which, however, is also not suitable for a tap changer.

References to the inventive use of at least one torque motor on a tap changer, however, can not be deduced from all these efforts to further develop the drive technology of switching devices.

According to the invention, such a torque motor can be provided as part of a tap changer at different locations. It can be arranged outside the transformer room, on top of the transformer or on the side of the transformer. It can also be arranged within the transformer room and there replace the power storage of the diverter switch, the fine-vote drive or a preselector drive or even more of these modules.

The use according to the invention of one or more torque motors, whereby newly structured positioning units are formed, has numerous advantages. First of all, neither clutch nor separate transmission are required, which significantly reduces the number of parts. Furthermore, a compact construction is realized. Due to the low elasticity results in a high rigidity and by the low mass and the low moment of inertia high dynamics with the ability to realize jump-like movements and thus to make a conventional energy storage superfluous. Finally, any switching step regardless of the particular effective counter-torque can be imprinted on a suitable control, which z. B. temperature influences can be largely excluded.

The invention will be explained in more detail by way of example with reference to schematic representation.

Figuren 1 bis 3

bereits erläuterte Antriebszüge bekannter Stufenschalter vom Typ des Widerstandsschnellschalters in schematischer Darstellung

Figuren 4a, 4b und 5a, 5b

schematische Möglichkeiten der erfindungsgemäßen Anwendung mindestens eines Torque-Motors bei einem Laststufenschalter dieses Typs

Figur 6a, 6b

schematische Möglichkeiten der erfindungsgemäßen Anwendung mindestens eines Torque-Motors bei einem Lastwähler dieses Typs

Figuren 7 und 8

bereits erläuterte Antriebszüge bekannter Stufenschalter vom Typ des Reaktorschalters in schematischer Darstellung

Figuren 9a, 9b, 10a, 10b und 11a, 11b

schematische Möglichkeiten der erfindungsgemäßen Anwendung mindestens eines Torque-Motors bei einem ersten Stufenschalter dieses Typs

Figuren 12a, 12b

schematische Möglichkeiten der erfindungsgemäßen Anwendung mindestens eines Torque-Motors bei einem zweiten Stufenschalter dieses Typs.

Show it:

FIGS. 1 to 3

already described drive trains known tap changer of the type of resistance rapid switch in a schematic representation

FIGS. 4a, 4b and 5a, 5b

schematic possibilities of the inventive application of at least one torque motor in an on-load tap-changer of this type

Figure 6a, 6b

schematic possibilities of the inventive application of at least one torque motor in a load selector of this type

FIGS. 7 and 8

already explained drive trains known tap changer of the type of reactor switch in a schematic representation

FIGS. 9a, 9b, 10a, 10b and 11a, 11b

schematic possibilities of the inventive application of at least one torque motor in a first tap-changer of this type

Figures 12a, 12b

schematic possibilities of the inventive application of at least one torque motor in a second tap-changer of this type.

In the following schematic diagrams, the assemblies according to the invention, each containing a torque motor, respectively referred to as "positioning unit" and highlighted in gray. Italics in the respective field the concrete function is listed, the respective Torque engine, d. H. the respective positioning unit, executes.

In Figure 4a is shown for the location of a tap changer outside the transformer that here according to the invention a torque motor replaced the previous motor drive and the downstream transmission and acts directly on the energy storage of the diverter switch, the Maltese transmission of the fine selector and possibly also the preselector. Below is another embodiment of the invention is shown schematically, in which a torque motor in addition to the previous power storage of the prior art and the associated gearbox replaced, such that this new positioning with torque motor directly to the Geneva drive of the fine vote and, if necessary The preselector acts as well as the diverter switch is operated directly. This second embodiment can also be arranged overall within the transformer, as shown in FIG. 4b.

In the figures 5a and 5b further embodiments of the invention are shown schematically. In Figure 5a is shown for a location of the tap changer outside the transformer that a first torque motor according to the invention directly actuates the diverter switch, by making the previous power storage superfluous (left positioning unit); Another torque motor (right positioning unit) directly actuates the Geneva transmission of the fine selector and, if necessary, the preselector. In contrast to the embodiments of the invention in Figure 4a and 4b, in each of which only a single torque motor is provided, so here are several such positioning units with torque motor shown. Underneath a modified embodiment of the invention is then shown, which provides a total of three such torque motors: a first positioning unit according to the invention (left) actuates directly - while avoiding a previous force accumulator - the diverter switch, a second positioning unit (middle) directly actuates the fine selector, and a third positioning unit (right) directly actuates the selection, if any. In Figure 5b, these embodiments of the invention are shown at a mounting location of the tap changer within the transformer.

In the context of the invention, it is also possible to spatially separate the diverter switch from the fine selector and possibly selection, d. H. to arrange both modules of the tap changer at different locations separately. Furthermore, it is possible to drive the fine selector and possibly selection separately by means of a known stepping motor. Since the voters are operated slowly and continuously, the disadvantage of the known stepper motors, namely their poor dynamic behavior, not disturbing here.

FIGS. 6a and 6b show, in the same schematic representation, possible embodiments of the invention in the case of a tap changer of the load selector type. FIG. 6a again relates to the arrangement of the tap-changer outside the transformer, FIG. 6b for one inside the transformer. The upper illustration in each case illustrates an embodiment in which a torque motor directly actuates the energy storage, which in turn rotates in a known manner, the switching column jumped and also optionally actuates the preselector. The middle diagram shows an embodiment of the invention, in which the torque motor also takes over the function of the previous energy storage and directly rotates the switching column jump. Finally, the lower illustration shows an embodiment with two separate torque motors, such that the first of these novel positioning units jumps directly over the switching column and the second positioning unit actuates an existing preselector separately.

In Figure 9a is shown for an arrangement of the tap changer outside the transformer in the upper half of the illustration that here according to the invention a torque motor replaces the previous motor drive and acts directly on the drive shaft and the reversing gear. The drive shaft in turn then actuates in each phase again selection, fine selector, bypass contact and the energy storage device (not shown), the vacuum switching cell. Below is a further embodiment of the invention is shown schematically, in which a torque motor in each phase in each case a new positioning, which also includes the previous deflection gear, forms. FIG. 9b shows the corresponding arrangements for a tap changer arranged in the transformer.

FIGS. 10a and 10b again schematically illustrate further embodiments of the invention. In Figure 10a is shown in the upper part that in each phase, a first torque motor means a gearbox at the same time preselector and fine selector operated and in each case a second torque motor the bypass contact and - again operated by the windable energy storage - the vacuum switching cell. Among them, a further embodiment of the invention is shown, which has a total of three such torque motors in each phase, which together with the corresponding gear form a separate positioning and directly each on the preselector or the fine or both the bypass switch and the energy storage of the vacuum switch cell Act. FIG. 10b again shows these embodiments for an arrangement of the tap changer in the transformer.

In FIGS. 11a and 11b, modified embodiments of the invention are shown again. In these embodiments, the hitherto underlying assignment of the individual components to each switching phases is resolved. A first torque motor actuates the preselection of all three phases, a second torque motor controls the fine-tuning of all two phases, and a third torque motor actuates both the bypass contacts and the energy storage and thus vacuum switching cells of all three phases.

In FIGS. 12a and 12b, in the same schematic representation, possible embodiments of the invention are shown in a further known generic tap changer whose known prior art gear train has been illustrated in FIG. 8 and has already been explained. The upper representations each show an embodiment in which a single torque motor in each case via intermediate gearbox the preselector, the fine selector and at the same time bypass contact and vacuum switching cell, in turn via a force storage device operated. The underlying middle representations each show an embodiment in which two such torque motors are provided in each phase. One of them actuates both preselector and fine selector, the other both bypass contact and energy storage of the vacuum switching cell. Finally, at the bottom of each another variant is shown in which three torque motors are provided for actuation in each phase: one for the preselector, one for the fine selector, one for the bypass contact and the energy storage of the vacuum switch cell. Again, it is possible to resolve the phased arrangement and perform in all the arrangements shown in Figure 12a and 12b, the actuations of the individual components described simultaneously for all three phases of the respective positioning. The illustrated figure 12a again refers to the arrangement of the tap changer outside the transformer, the figure 12b on its arrangement in the transformer.

Claims (16)

1. Tap changer for uninterrupted switching over between different winding taps of a tapped transformer according to the principle of a resistance quick-action switch, consisting of a fine selector and optionally a preselector for power-free selection of the winding tap to be switched over to subsequently, further consisting of a load changeover switch for subsequent rapid switching over from the previous winding tap to the preselected winding tap with transient switching in of at least one switching-over resistance, wherein not only fine selector and optional preselector, but also load changeover switch are actuable by a drive on each switching-over, characterised in that at least one torque motor constructed as a three-phase brushless synchronous motor with permanent excitation is provided as drive.
2. Tap changer according to claim 1, characterised in that the at least one torque motor actuates not only a known force store of the load changeover switch, but also the fine selector and optional preselector.
3. Tap changer according to claim 1, characterised in that at least one torque motor directly actuates not only the load changeover switch, but also the fine selector and optional preselector.
4. Tap changer according to claim 1, characterised in that at least one first torque motor respectively directly actuates the known force store of the load changeover switch and at least one second torque motor respectively actuates the fine selector and optional preselector.
5. Tap changer according to claim 1, characterised in that at least one first torque motor respectively directly actuates the load changeover switch, at least one second torque motor respectively directly actuates the fine selector and optionally at least one third torque motor respectively actuates the preselector.
6. Tap changer for uninterrupted switching-over between different winding taps of a tapped transformer according to the principle of a resistance quick-action switch, consisting of a load selector for simultaneous selection of the winding tap which is to be switched over to, as well as for rapid switching-over from the previous winding tap to the preselected winding tap with transient switching in of at least one switching-over resistance, wherein an abruptly actuable switching element, particularly a switch column, serves for the switching over, characterised in that at least one torque motor constructed as a three-phase brushless synchronous motor with permanent excitation is provided as drive.
7. Tap changer according to claim 6, characterised in that the at least one torque motor directly actuates a known force store which in turn abruptly moves the switching element in known manner and optionally actuates a preselector.
8. Tap changer according to claim 6, characterised in that the at least one torque motor directly abruptly moves the switching element and optionally actuates a preselector.
9. Tap changer according to claim 6, characterised in that at least a first torque motor directly abruptly moves the switching element and optionally at least a second torque motor directly actuates the preselector.
10. Tap changer according to one of claims 1 to 5, characterised in that the load changeover-switch on the one hand and the fine selector and optional preselector on the other hand are arranged to be physically separate and/or the fine selector and optional preselector is or are drivable separately by at least one stepping motor.
11. Tap changer for uninterrupted switching-over between different winding taps of a tapped transformer according to the principle of a reactor switch, consisting of a fine selector with two load branches, between which a vacuum switching cell is arranged in each phase to be switched, consisting of a preselector and of a bypass contact, which bridges over the vacuum switching cell each time and by which in turn at least one of the two load branches is connectible with the load shunt, as well as a force store which actuates the respective vacuum switching cell, wherein a single drive is provided which actuates all stated components by means of various transmissions and by drive shafts, characterised in that at least one torque motor constructed as a three-phase brushless synchronous motor with permanent excitation is provided as drive.
12. Tap changer according to claim 11, characterised in that the at least one torque motor actuates all drive shafts.
13. Tap changer according to claim 11, characterised in that three separate torque motors are arranged in such a manner that each of them actuates the components of one phase, namely preselector, fine selector, bypass contact and force store of the associated vacuum switching cell.
14. Tap changer according to claim 11, characterised in that two separate torque motors are provided for each phase, of which one actuates preselector and fine selector and the other actuates bypass contact and force store of the vacuum switching cell.
15. Tap changer according to claim 11, characterised in that three separate torque motors are provided for each phase, of which respectively one actuates the preselector, one actuates the fine selector and one actuates not only the bypass contact, but also the force store of the vacuum switching cell.
16. Tap changer according to claim 11, characterised in that in total three separate torque motors are provided, of which one actuates the preselectors of all three phases, another actuates the fine selectors of all three phases and the third actuates not only the bypass contacts, but also the force stores of the vacuum switching cells of all three phases.

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