WO2016050490A1

WO2016050490A1 - Vacuum interrupter

Info

Publication number: WO2016050490A1
Application number: PCT/EP2015/070924
Authority: WO
Inventors: Georg Bachmaier; Andreas GÖDECKE; Sylvio Kosse; Thomas Vontz; Wolfgang Zöls
Original assignee: Siemens Aktiengesellschaft
Priority date: 2014-09-30
Filing date: 2015-09-14
Publication date: 2016-04-07
Also published as: DE102014219772A1

Abstract

The vacuum interrupter comprises a first (20) and a second switching contact (25) and a hydraulic drive (75) by means of which the first (20) and the second switching contact (25) can be brought into contact or out of contact.

Description

description

Vakuumsehaltröhre The invention relates to a vacuum interrupter tube.

Vacuum interrupters are today for switching medium and increasingly high voltage state of the art. Its spread continues to increase, partly because based on SF6 (sulfur hexafluoride) switchgear due to the klimaschädli ^¬ chen effect of SF6 are increasingly being forced out of business. However, the substitution of SF6 as an insulating egg ^¬ ne challenge, as other insulating gases have a lower dielectric strength and therefore the switchgear surfactant-denziell less can be made compact.

There is therefore a need for approaches to be able to build compact switchgear despite the absence of SF6 as a switching and insulating medium. Particular attention is paid to the overall consideration of interrupter and drive.

The most common approach to replace SF6 in medium voltage switchgear is the use of vacuum interrupters, along with alternative insulating gases such as nitrogen or carbon dioxide or solid state insulators.

The compact design of the drive is a basic requirement for a compact overall switchgear. For example, in

EP2312606B1 describes the use of a magnetic drive in the same housing as the tube, which results in a particularly unit. While older systems (e.g., the ABB system VM1) often have a leverage between the drive and the vacuum interrupter tube, recent work such as e.g.

CN201788887U or CN202159623U a direct drive before, ie a direct, and thus compact, connection between the actuator and vacuum interrupter. A similar arrangement is given in the so-called "Reclosern", where the vacuum interrupter is also driven by a direct drive by means of magnetic drive (see for example EP0580285A2 or CN2350863Y).

Finally, in DE000010238950B4 an arrangement is described, which brings together the vacuum interrupter and drive so far that the latter is not only housed in the same housing, but even in the vacuum region of the interrupter. Furthermore, there is described that the drive is maintained at the electrical potential of the medium voltage, which can be dispensed ver ^{¬ to} electrical insulation between the drive and the interrupter. Both approaches allow a particularly compact design.

Against this background, it is an object of the invention to provide an improved vacuum interrupter. In particular, the vacuum interrupter should be able to be built compact. Suitably ^¬ SSIG to the vacuum interrupter highly dynamically operable pre- zise controllable and be robust formable.

This object is achieved with a vacuum interrupter with the features specified in An ^¬ claim 1. Preferred Wide Erbil ^¬ developments of the invention are specified in the associated dependent claims, the following description and the drawing.

The vacuum interrupter according to the invention comprises a first and a second switching contact and a hydraulic drive, by means of which first and second switching contact can be brought into or out of contact position. Suitably, in the vacuum interrupter according to the invention, the hydraulic drive is a piezo-hydraulic drive. Just one

piezohydraulic drive is particularly well integrated into the vacuum interrupter. In particular, a bellows already present in conventional vacuum interrupters, for example, can be used directly as a drive bellows. The resulting com pact ^¬ structure allows a flexible positioning of the vacuum interrupter in a switchgear ^¬ and thus optimum Isolation distances. As explained in the introduction, this is particularly important for the construction of SF6-free switchgear.

Hydraulic drives, in particular piezohydraulic drives, are advantageously highly dynamically operable, as well as precisely controllable and also very robust. Consequently, the erfindungs ^¬ proper vacuum interrupter tube is highly dynamic and precise operation and robust and low maintenance interpretable. Preferably, the vacuum interrupter according to the OF INVENTION ^¬ extension comprises at least one spring element, by means of which at least the first switching contact can be deflected into a contact position with the two ^¬ th switching contact. In this way, the first switching contact can be deflected in a resonant frequency of the spring element. In this way the erfindungsge ^¬ Mäss expected drive compensates for only the losses and can thus be made particularly small and efficient.

In an advantageous further development of the vacuum interrupter according to the invention the first switching contact, preferably rigidly, to a free end of the at least one motion-coupled Federele ^¬ management.

Preferably, in the vacuum interrupter according to the invention, the spring element by means of the hydraulic drive auslenk ^¬ bar.

Suitably, in the vacuum interrupter according to the invention, the first switching contact is arranged on a conductor bolt, to which the free end of the at least one spring element is bound to ^¬ .

Advantageously, at least two spring elements are provided in the vacuum interrupter according to the invention.

Suitably, in the vacuum interrupter tube according to the invention He ^¬ encapsulated hydraulic drive, preferably together with hydraulic fluid. The high internal damping of Hydraulic fluid advantageously prevents problems with high-frequency vibrations. A, expediently metallic, encapsulation of the actuator in the hydraulic fluid keeps the on ^¬ operating robust against pollution, aging or aggressive chemicals ( "harsh environments"). The vacuum interrupter according to the invention is therefore virtually maintenance-free and is particularly suitable for high availability applications.

In an advantageous development of the vacuum interrupter according to the invention, the hydraulic drive has a Hydrau ^¬ likpumpe. Appropriately, in the vacuum interrupter according to the invention, the hydraulic pump is a piezohydraulische Pum ^¬ pe.

Preferably, in the case of the vacuum interrupter according to the invention, the piezohydraulic pump has a hydraulic line and a volume-variable hydraulic chamber connected thereto and a piezo plate, which is connected to the hydraulic chamber in such a way that it deflects in a volume-changing manner.

Suitably, the hydraulic line rectification elements in the inventive vacuum switch ^¬ tube. Ins ^¬ special rectification elements Rückschlagven ^¬ tilen formed. Appropriately, a flow is caused by volume changes of the hydraulic chamber, which is rectified by means of the rectification elements, so that a kon ^¬ continuous pump flow takes place.

Preferably, the vacuum interrupter at least one

Locking means, by means of which at least the first

Switching contact, at least temporarily, in one or out of a contact position can be fixed.

In particular, the at least one locking means is in the vacuum interrupter according to the OF INVENTION ^¬ dung at least a magneti ^¬ ULTRASONIC locking means. Alternatively or additionally, and preferably also the at least one locking means at least ^¬ a mechanical locking means. Advantageously, the vacuum interrupter at least one vacuum interrupter tube housing, wherein the drive is arranged in the vacuum umschaltröhrengehäuse. By installing the drive in the vacuum interrupter housing, the drive is suitably at high voltage potential. This avoids the installation of large, heavy insulation bodies between the drive and vacuum interrupter. Since these insulation body must always be moved, they negatively affect the performance of the vacuum interrupter or make a larger and therefore more expensive design of the drive necessary. Both problems are avoided according to the invention.

The invention will be explained in more detail with reference to an embodiment shown in the drawing.

Show it:

Fig. 1 is a vacuum interrupter according to the invention with a piezohydraulic pump schematically in

Longitudinal section

Fig. 2 in accordance with the piezo-hydraulic pump of the vacuum switching tube ^¬. 1 in a schematic diagram,

Fig. 3 shows a further embodiment of a vacuum ^¬ interrupter with a magnetic holding device schematically in longitudinal section and Figure 4 shows another embodiment of a vacuum ^¬ interrupter with a mechanical holding device schematically in longitudinal section.

The vacuum interrupter according to the invention shown in FIG. 1 comprises a substantially circular-cylindrical vacuum region 5. Within the vacuum region 5, an electrical switch 10 is located with an axial, ie parallel to the longitudinal central axis of the circular cylindrical Vakuumbe-. The first switching contact 20 is resiliently deflectable such that it can be deflected between two deflection positions: in a first deflection position, the first contact is in contact with the first switching contact 20 Switching contact 20, the second switching contact 25, so that the switch 10 turns on in this deflection position of the first switching contact 25 at normal operating voltages. In a second

Switching position, the first switching contact 20 is sufficiently spaced from the second switching contact 25, so that no lei ^¬ tende connection of the switch 10 is made. For this purpose, the first 20 and second switching contact 25 are each formed as contact discs, which face each other and each ^¬ Weils frontally aligned with each other axially aligned in the Vaku ^¬ umbereich 5 contact pins 30, 35 are attached. The two contact pins 30, 35 are made in the illustrated embodiment of copper and form when switching the switch 10 together from a copper conductor.

A first 30 of the contact pins 30, 35 projects into the vacuum region 5 in a stationary manner. The other, second, contact pin 35, however, which carries the first switching contact 20 is, relative to the vacuum wall 15, resiliently held. To this end collar on the second contact pin 35 on the outer circumference two axially spaced apart projections 40 (the switching contacts 20, 25 close) and 45 (the switching contacts 20, 25 away) from, to which in each case an axially disposed helical spring 50, 55 from ^¬ supports. The two axially arranged coil springs 50, 55 extend counter to each other and are supported axially spaced from one another at a radially from the Vakuumwan ^¬ tion 15 on the second contact pin 35 to be projected

Housing collar 60 (the switch contacts 20, 25 close) and 65 (the switch contacts 20, 25 remote) from. In this way, the second contact pin 35 is held axially resilient, so that the first switching contact 20 can spring between the first and second switching position. From the function of the current separation results for the operation in particular the requirement that the second contact ^¬ bolt 35 after a certain time, for example ti = 2 milliseconds, the first 20 of the second switching contact 25 in a certain minimum distance, for example Δχ = 2mm ge - must have brought. By assuming a sinusoidal oscillation with a total amplitude of x0, the resonant frequency can be determined to be ω = 1 / tL ^■ cos ^_1 ((x ₀ - Δχ) / χ ₀ ).

Furthermore: ω = ^ k / m with the moving mass m. Thus, it is also possible to directly calculate the necessary spring stiffness k.

The resilient movement of the second contact pin 35 is driven by ^{¬ means of} a piezohydraulic drive:

For this purpose, two piezohydraulic pumps 75 are integrated in a housing 70 of the vacuum interrupter.

The piezohydraulic pumps 75 each drive an axially movable pilot piston 80, which at one of the second

Contact pin 35 radially projecting perforated disc 85 is attached. Thus, the piezo-hydraulic pumps 75 simultaneously drive the second contact pin 35. The pilot piston 80 are matched to the impedance of the piezo-hydraulic pumps 75: TY pisch typically exhibit piezo-hydraulic pump while high pump ^¬ press, but tends to be rather low pump speeds on. Consequently, the pilot piston diameters are chosen as small as possible. The pilot pistons 80 run into bores which are hydraulically connected to the piezohydraulic pumps 75. The mode of operation of the piezohydraulic pumps 75 will be explained in more detail with reference to FIG. 2.

A piezoelectric actuator 200 is firmly clamped on the one hand in a clamping 205 and on the other hand has a free end 210, which is deflectable relative to the clamping 205. The free end 210 of the piezoelectric actuator 200 is connected to a Hydrau ^¬ likvolumen 215, so that a deflection of the free end 210 of the piezoelectric actuator 200, the hydraulic volume chan ged ^¬ 215th In the exemplary embodiment shown, the hydraulic volume 215 is formed with a hydraulic chamber 220 with a hydraulic piston 225 guided therein, which is connected to the piezoelectric actuator 200. Alternatively, in a further, not specifically illustrated embodiment of the piezoelectric actuator 200 may be frontally connected to a bellows. This may change as-promoting hydraulic volume 215 pumps now hydraulic liquid ^¬ ness by a tethered to the hydraulic volume 215 Hyd ^¬ raulikleitung 230. Check valves 235 on either side of Hyd ^¬ raulikvolumens 215 direct the flow of the hydraulic fluid in the hydraulic line 230 in a direction R the same. The current flowing through the hydraulic line 230 hydraulic liquid ^¬ ness drives each pilot poppet 80th

In principle, one of the check valves 235 may also be replaced by a simple throttle. The activation of the

Piezo plate 200 takes place for example by means of a harmonious ^¬ African input voltage, such as a sinusoidal input voltage. In principle, however, the piezo control can also be effected with a symmetrical or asymmetric sawtooth voltage.

The second and of the housing 70 contact pin 35 formed intermediate space 240 is axially by means of metal bellows 245, 250 sealed from ^¬: Thus, a first metal bellows covers 245, A second metal bellows 250, however, extends from the switch contacts 20, 25 remote housing collar 65 to the switch contacts 20, 25 distant projection 45 of the switch contacts 20, 25 near housing collar 60 second contact pin 35. The metal bellows 245, 250 thus encapsulate both the piezohydraulic pumps 75 and the two coil springs 50, 55 completely. The thus enclosed intermediate space 240 is filled with hydraulic fluid.

The pilot piston 80 with the second contact pin coupling perforated disc 85 abuts in the first deflection position of the switching contact 20 to an axial stop 255 and in a second deflection position of the switching contact 20 to an axial stop 260.

In a further in Fig. Exemplary embodiment shown in Figure 3, which corresponds to the embodiment described above, moreover, are on the second contact pin 35 in addition locking means in the form of a radially continue executing from the two ^¬ th contact pin 35 ferromagnetic disk 265 is provided which both the First and in the second deflection position in each case to a arranged on the inner side of the housing 70 permanent magnet 270 comes to rest. The permanent magnets 265, 270 thus hold by their magnetic forces, the ferromagnetic disk 265 and thus the contact pin 35 and thus the first switching contact 20 in the first and the second axial Ausstellstel- ment each stable for a short period of time.

Alternatively, as shown in Fig. 4 in a further embodiment, a mechanical locking means is provided: The mechanical locking means comprises two on the second Kon ^¬ clock pin 35 hinged leg 275, which extend from this. The two legs 275 extend in each case against compression springs 280 which extend from the housing 70 in the direction of tion on the second contact pin 35 to entgegenstrecken. Guided by the legs 275 is a respective punch 285, which compresses the compression springs 280. If the second contact pin 35 is located in an axial position between the first and second deflection position, then the legs 275 extend straight perpendicular to the axial extent of the contact pin 35 against the compression springs 280 and compress them maximally by means of the punches 285. From this axial Po ^¬ position, the second contact pin 35 is consequently always driven axially in the first or second deflection position. Also in this embodiment, therefore, the second contact ^¬ bolt 35 is locked in the first and second deflection position for a certain period of time. To compensate for the temperature-related volume expansion of the hydraulic fluid, a per se known, suitable compensating container is further coupled (not shown in the individual ^¬ nen). For example, such a compensation ^¬ ratio is realized as another bellows, which is hydraulically connected via a throttle to the encapsulated gap 240.

The housing 70 is at the same electrical potential as the second contact pin 35. Therefore, the operating energy for the drive must be brought to this potential without making a conductive connection between the lying on Erdpo ^¬ potential switching device housing and the drive housing. There are various possibilities for this: For example, a fiber optic energy transmission

As is known in the high-voltage transmission sector, energy is coupled via a laser into a fiber and into the drive-related one

Electronics using photocell again converted into electrical energy. Since the fiber is electrically non-conductive, so flexible energy over almost any distance can be transmitted to high ^¬ voltage ^potential . Furthermore, energy can be inductively coupled in, for example via two opposing coils. The coils are separated for example by a sufficiently sized solid state insulator, such as a ceramic body. Alternatively, the coils are housed in a vacuum area, so that the excellent insulating effect of the vacuum can be used.

Claims

claims

1. vacuum interrupter, comprising a first (20) and a second switching contact (25) and a hydraulic drive (75), by means of which first (20) and second switching contact (25) can be brought into or out of contact position.

2. Vacuum interrupter according to claim 1, wherein the hydrau ^¬ lic drive is a piezohydraulischer drive (75).

3. vacuum interrupter, comprising at least one spring element, by means of which at least the first switching contact (20) in ei ^¬ ne contact position with the second switching contact (25) from ^¬ steerable.

4. vacuum interrupter according to one of the preceding claims, wherein the first switching contact (20), preferably rigidly, with a free end of the at least one spring element (50, 55) is coupled for movement.

5. vacuum interrupter according to one of the preceding claims, wherein the spring element (50, 55) by means of the hydraulic ^¬ 's drive (75) is deflectable.

6. vacuum interrupter according to one of the preceding claims, wherein the first switching contact (20) on a Leiterbol ^¬ zen (35) is arranged, on which the free end of the at least ^¬ one spring element (50, 55) is connected.

7. vacuum interrupter according to one of the preceding claims, wherein at least two spring elements (50, 55) are provided.

8. vacuum interrupter according to one of the preceding claims, wherein the hydraulic drive (75), preferably ge ^¬ together with hydraulic fluid, is encapsulated.

9. vacuum interrupter according to one of the preceding claims, wherein the hydraulic drive (75) comprises a hydraulic pump.

10. vacuum interrupter according to the preceding claim, wherein the hydraulic pump is a piezohydraulische pump (75).

11. Vacuum interrupter according to the preceding claim, wherein the piezohydraulic pump (75) has a Hydrauliklei ^¬ device (230) and a volume-variable hydraulic chamber connected thereto (215) and a piezoelectric actuator (200), which connected to the hydraulic chamber (215) volume-deflectable connected is.

12. vacuum interrupter according to the preceding claim, wherein the hydraulic line (230) rectifying elements (235).

13. vacuum interrupter according to one of the preceding Ansprü ^¬ che, which at least one locking means (270; 275, 280) on ^¬ has, by means of which at least the second switching contact, at least temporarily, in a switch contact position or a Ausschaltkontaktstellung can be fixed.

14. vacuum interrupter according to the preceding claim, wherein the at least one locking means (270) is at least one magnetic locking means.

15. vacuum interrupter according to one of the two preceding claims, wherein the at least one locking means (275, 280) is at least one mechanical locking means.

16. Vacuum interrupter according to one of the preceding claims, comprising at least one vacuum interrupter housing (70), in which the drive (75) in the vacuum interrupter housing (70) is arranged.