Unitized phase over phase two-way or three-way high voltage switch assembly with one vacuum interrupter per phase

Switch gear for interconnecting a plurality of power transmission lines including a number of high voltage switches arranged in three phases for routing power in multiple directions. The switches are pre-mounted on a beam to form a three phase unit as a unitized assembly which is attached in the field to a vertical support structure. Each phase includes a vertical break switch and two side break switches for a three-way switch. For a two-way, each phase includes two side break switches. The vertical break switch and the two side break switches for each phase are operatively and electrically connected to a common electric power interrupter. The unitized assembly for each phase has the insulators and power interrupter arranged in cantilevered horizontal relationship with the beam which is attached to the vertical support structure. Operating links between phases are operatively connected in a push-pull relationship with the high voltage outdoor electric switches.

BACKGROUND OF THE INVENTION

The invention relates to a unitized phase over phase two-way and three-way high voltage switch assembly for electrical switchgear such as air break disconnect switches used in transmission for the routing of power in multiple directions. And, in particular, to such a two-way and three-way high voltage switch assembly utilizing a single vacuum interrupter per phase.

U.S. Pat. No. 3,226,499 issued to Thomas E. Curtis, et al. on Dec. 28, 1965, which is incorporated herein by reference, discloses a load break switch gear including a plurality of side air break switches in combination with a single load interrupting switching device. The Curtis apparatus includes means for interconnecting each air break switch with the load interrupter during opening of the air break switches. The Curtis load interrupter includes a plurality of serially connected vacuum-break interrupters. Tandem operation of any number of vacuum-break interrupters is provided, whereby the transmission line voltages that maybe interrupted are greatly increased. The Curtis apparatus includes a frame54, that as depicted inFIG. 2of Curtis, is triangularly shaped and extends horizontally from a power pole56. As depicted inFIG. 1of Curtis braces apparently are attached below the frame54for support. Rotary insulators48,50and52are vertically arranged at the corners or vertexes of the frame54. A load interrupter40is secured to a support insulator66mounted centrally within the perimeter of frame54. The load interrupter40is for extinguishing the arc upon opening of main switches28-32, as described in detail in the aforesaid patent.

Traditionally such switch gear assemblies in a two-way or three-way switch configuration with one vacuum interrupter per phase in a three phase system have had problems with phase over phase spacing for a given voltage requiring special long expensive transmission poles. The phase over phase spacing is the minimum permissible distance between electrical phases. For example, the three-way switch assembly manufactured by Turner Electric Corporation of 9510 Clair Avenue, Fairview Heights, Ill. 62208 requires for a 115 kv switch assembly a minimum phase spacing of twenty feet. As described in Turner Electric Corporation sales brochure, entitled “Air Break Switch 3D-D001, Teco Air Switches, 15 KV-161 KV”, copyright Turner Electric Corporation 1983, a relatively large phase spacing is required because of structural braces which are at electrical ground potential. The Turner air break switch is similar in structure and operation to the above-mentioned load break switch gear patent by Curtis. Braces are also required for the Turner switch because, for example for each phase in a 3-way arrangement; three side break switches are affixed to an equilateral triangular bracket arrangement attached to a vertical transmission pole in a similar manner as mentioned for the Curtis patent. The braces support the triangular bracket arrangement. One end of each of the side break switches is supported by a rotatable vertical insulator attached at one end to each vertex or corner of the triangular bracket. A vacuum interrupter is arranged coaxially vertically above another insulator which is stationary and positioned about in the center of the triangular bracket. The vacuum interrupter is supported by a cross member attached at one end at a vertex of the triangular bracket and at the other end to about the center of the opposite side of the bracket. The braces are attached at one end to the pole at a distance below the triangular bracket and at the other end at about each vertex of the triangular bracket. This arrangement requires a minimum clearance between the top of the vacuum interrupter and the brace supports to avoid establishing a path to ground via the interrupter and the triangular bracket supports. Also, in conjunction with this Turner switch assembly, as a common practice, a purely torsional drive is used for opening and closing each switch, which makes adjusting the switching sequence between phases very random due to the “wind-up” of the pipe which is in torsion. Also, with such three-way switches when installing the switches it is very time consuming because each phase has to be installed separately and the mechanical operating mechanism between the phases is field installed and adjusted.

U.S. Pat. No. 4,492,835 by John L. Turner, issued Jan. 8, 1985, which is incorporated herein by reference, describes a typical high voltage load interrupter device having a plurality of load interrupter contacts enclosed respectively in axially aligned vacuum bottles, each bottle containing a fixed contact and a second contact movable axially away from the fixed contact to open position and toward the fixed contact to closed position by an actuating mechanism. The bottles are positioned in a tubular housing of dielectric material by a series of stacking pedestals each formed with three equi-angularly spaced radial arms engaging the inner surface of the tubular housing. Each movable contact is normally resiliently biased toward closed position and is moved to open position by a toggle of the actuating mechanism having a pair of arms substantially aligned with the contacts and held in position by springs connected to arms on the operating shaft such that when the operating shaft is rotated by the operating arm, the above-mentioned springs break the toggle, causing the individual contacts to open. A reset spring returns the operating shaft and operating arm to ready position and causes the toggle to return the contacts to their normal closed positions.

It is therefore an object of the present invention to devise an improved phase over phase three-way switch assembly that overcomes the large space requirement of the prior art switch assembly requiring such brace supports between phases; and which has a more positive semi-non-torsional acting switch mechanism; and which is much less time consuming to adjust and which installs quicker as a unitized multi-phase assembly on a beam member. A two-way switch assembly is also disclosed.

SUMMARY OF THE INVENTION

The untized phase over phase two-way or three-way switch assembly of the present invention solves the problems of the prior art arrangement. The two-way or three-way switch assembly of the present invention is a phase over phase arrangement which, in the case of a three-way assembly, includes three arrays of three-way switches, i.e., three switches per phase, pre-mounted on a beam, one array for each phase. The beam in the operative position is vertical and attached to a vertical transmission pole. The cylindrically-shaped insulators of the present invention are cantilevered in such a manner that their axes extend axially horizontally in a cantilevered fashion from the vertical transmission pole, as opposed to the prior art arrangement with all the switch insulators being vertically oriented with their axes, vertically arranged, parallel to the vertical transmission pole. The unitized three phase three-way switch assembly is fully factory adjusted before being shipped to the job site. This arrangement of switches being pre-mounted on a beam for installation on a utility pole in a phase over phase arrangement is called a untized switch arrangement. The switches of the present invention for each phase are driven by a “push-pull” mechanical linkage instead of the prior art purely torsional drive which have so-called “wind-up” problems because of the length of pipe used to engage the switches. Together with a single power interrupter the array of three-switches for each phase forms a switching unit that is mounted to the beam without the need of the previously mentioned prior art support braces for the triangular bracket, for example, thereby reducing the minimum required distance between phases for a particular voltage switch assembly.

For a three-way switch configuration of the present invention, each array of three-switches includes a vertical break switch mounted between two side break switches, as opposed to the typical prior art arrangement of the previously described U.S. Pat. No. 3,226,499 issued to Curtis, et al and the three-way switch assembly previously described of Turner Electric Corporation which both use three side break switches for each phase. When either side break switch of the present invention opens, there is less electrical clearance to the vertical break switch parts as opposed to the use of a side break switch which would open to create an electrical clearance problem. Also, the horizontally mounted side break switch insulators of the present invention are preferably mounted with their axes in the same horizontal plane as the axis of the vacuum interrupter, this further reduces the electrical clearance between phases as opposed to the prior art arrangement which positioned the interrupter vertically in the center of the triangular bracket and which required the problematic supporting cross member and braces as previously mentioned. For a two-way switch configuration of the present invention the vertical break switch is eliminated.

These and other aspects of the present invention will be further understood from the entirety of the description, drawings and claims.

DETAILED DESCRIPTION OF THE PARTICULAR EMBODIMENTS

FIG. 1shows a unitized phase over phase high voltage 3-way high voltage switch assembly10mounted to an electric utility vertical pole12which typically is concrete or steel. The switch assembly10can handle voltages of, for example, 69 kV (thousand volts) to 161 kV with current carrying capacity of 1200 amperes to 2000 amperes. The switch assembly10is adapted to be engageable with a three phase alternating current electrical power system which includes an upper phase ‘A’, an intermediate phase ‘B’ and a lowest phase ‘C’. The phase over phase 3-way switch assembly is typically operatively attached and engageable with three motor operators14a,14b, and14c. The motor operators14a,14b,14cmay be such as sold by Cleaveland/Price Inc., the present assignee, as motor operator model no. TPC. More details of the attachment of the motor operators14a,14b,14cto respective switches will be described subsequently.

Each of the three phases ‘A’, ‘B’ and ‘C’ has three switches16a,16b, and16carranged in an array corresponding to each phase as shown inFIGS. 1 and 2. The three switches16a,16b,16cin each array can route electrical power in three ways as is known in the art. As can be seen, for example, fromFIG. 3with reference to lowest phase ‘C’, two stationary cylindrical insulators18a,18bare attached at one end19a,19bin a cantilevered horizontal fashion respectively to horizontal frame20aand vertical frame20b. The horizontal frame20aand vertical frame20bare attached to vertical beam20which in turn is attached to the vertical pole12. As can be seen by reference toFIG. 3, horizontal frame20ais arranged perpendicular to the vertical beam20. The switch16cis a vertical break switch and is attached between the two stationary insulators18a,18band opens as shown inFIG. 4. Two rotating cylindrical insulators22a,22bare positioned and attached at one end23a,23bin cantilevered horizontal fashion on the frame20a. The rotating cylindrical insulators22a,22boperate the switches16a,16bwhich are side break switches which open as shown inFIG. 4. As shown inFIG. 4, supported also in a cantilevered horizontal fashion coaxially at one end29aby stationary insulator18ais a cylindrical vacuum interrupter24, also attached to frame20a. As shown inFIG. 3. desirably, the horizontally mounted side break switch insulators22a,22bof the present invention are preferably mounted with their axes, respectively ‘L’ and ‘M’, lying in substantially the same plane ‘X’, which preferably is a horizontal plane. Also lying in the same plane ‘X’ is the axis ‘V’ of the vacuum interrupter24and the stationary insulator18awhich are coaxial. The vacuum interrupter24houses a plurality of vacuum bottles (not shown), as described in the previously mentioned Turner U.S. Pat. No. 4,492,835, electrically connected in series circuit arrangement for extinguishing the arc caused by the opening of a switch. The vacuum interrupter24at the other end29bincludes rotatable operating shaft26having side portions26a,26bhaving side break interrupter trip arms27a,27brespectively attached thereto as can be seen by reference toFIGS. 3, 4 and 6. The vacuum interrupter24also has attached at the end29b, a vertical break trip arm28as shown inFIGS. 3 and 6. The trip arm28is used for tripping the vacuum interrupter24when the vertical break switch16copens to open contacts within each vacuum bottle (not shown) for extinguishing an arc. Blade trip bar46shown inFIG. 4is attached to vertical break switch16cand engages with arm28as the switch opens. The trip arm28is attached as shown inFIG. 6to rotatable shaft side portion26b. Blade trip bars44a,44bare respectively attached to switches16a,16b. When side break switch16aopens, it actuates trip arm27ato trip the vacuum interrupter24. In a similar manner, when side break switch16bopens it actuates trip arm27bto trip the vacuum interrupter24.

A first transmission line30from a first power source or load32, indicated by a dashed square inFIGS. 3 and 4, is attached to a first strain insulator34which insulates the transmission line30from pole12while providing sufficient support for the transmission line. Electrical current through first transmission line30is conducted via first jumper conductor36to hinge end80bof side break switch16b. The blade end82bof side break switch16bcontacts a jaw84bat the one end29aof the vacuum interrupter24, as shown inFIG. 6. A second transmission line31from a second power source or load33, indicated by a dashed square inFIGS. 3 and 4, is attached to second strain insulator37. Electrical current through second transmission line31is conducted via second jumper conductor39to hinge end80aof side break switch16a. The blade end82aof side break switch16acontacts jaw84aat the one end29aof the vacuum interrupter24. A third transmission line40from a third power source or load41, indicated by a dashed square inFIGS. 3 and 4, is attached to third strain insulator42. Electrical current through the third transmission line40is conducted via jumper conductor43to the hinge end80cof vertical break switch16cbetter shown inFIG. 5. The blade end82cof vertical break switch16cmakes contact at jaw84cat the one end29aof the vacuum interrupter.

The motor operators14a,14b,14care preferably attached near the bottom of the pole12so as to be easily accessible for servicing and operation. The pole12may be 100 feet in height, for example. Of course instead of the use of three motor operators, the switches may be operated manually to provide rotary motion by three manual rotary operators such as a swing handle or geared hand crank, not shown in the drawings. Torsional drive pipes50a,50b,50care respectively operatively attached to motor operators14a,14b,14cand as shown inFIGS. 1 and 2extend upwardly to gear boxes52a,52b,52c. The gear boxes52a,52b,52cmay be such as manufactured and sold by Cleaveland/Price Inc., the present assignee. The gear boxes52a,52b,52cconvert torsional motion to push-pull motion. The motor operators14a,14b,14c, may also be such as manufactured and sold by Cleaveland/Price Inc., the present assignee, and provide torsional or rotary motion to the lower drive pipes50a,50b,50c. The torsional drive pipes50a,50b, and50cmay be 40 feet to 60 feet in length, for example. The gear boxes52a,52b,52care mounted on bottom member54which is attached to beam20. Extending upwardly respectively from gear boxes52a,52b,52care lower push-pull links56a,56b,56cshown inFIGS. 3 and 4. The gear boxes convert the torsional movement of torsional drive pipes50a,50b,50cto a push-pull movement of the lower push-pull links56a,56b,56c. The lower push-pull links56a,56b,56ctransmit the push-pull motion to the three phases ‘A’, ‘B’ and ‘C’ as follows. The lower push-pull links56a,56b, respectively extend from gear boxes52a,52bto rotating insulator lever60a,60bbetter seen inFIG. 3. The lower push-pull link56cis connected to lever60cwhich rotates horizontal shaft62which rotates lever86which operates push-pull insulator74cto open switch16c, as shown inFIGS. 3 and 4.

The other end of lower horizontal shaft62is attached to lever64. Intermediate links58a,58b,58crespectively extend upwardly from phase ‘C’ to phase ‘B’ and upper links70a,70b,70cextend from phase ‘B’ to phase ‘A’ as shown inFIGS. 1 and 2. The operation of phases ‘B’ and ‘A’ are the same as for lowest phase ‘C’ and therefore is not repeated.

With reference toFIGS. 1 and 3, activation of motor operator14b, for example, causes a rotational movement of torsional drive pipe50bwhich per gear box52bconverts the rotational movement to a linear push-pull movement of lower link56bto open switch16b. With reference toFIG. 1, assuming side break switch16bfor each phase is closed with the resulting movement of gear box52b, the lower link56b, the intermediate link58band the upper link70b, constitute an operating link unit88bare caused to move in unison to rotate insulators22bto simultaneously cause all three side break switches16bof phases ‘A’, ‘B’, and ‘C’ to open, as shown inFIG. 2. As the side break switch16bopens it cases side break interrupter trip arm27bto move to actuate the vacuum interrupter24. A similar operation occurs with regard to the opening and closing of the other side break switch16aand vertical break switch16c. Side break switch16aof each phase ‘A’, ‘B’, and ‘C’ is caused to open by the movement of gear box52awith resulting movement of the lower link56a, the intermediate link58aand the upper link70a, constituting an operating link unit88a, are caused to move in unison to rotate insulators22ato simultaneously cause all three side break switches16aof phases ‘A’, ‘B’, and ‘C’ to open. Likewise, vertical break switch16cof each phase ‘A’, ‘B’, and ‘C’ is caused to open by the movement of gear box52cwith resulting movement of the lower link56c, the intermediate link58cand the upper link70c, constituting an operating link unit88c. With reference toFIGS. 3 and 4, with regard to the vertical break switch16c, it has blade trip bar46attached. When the vertical break switch16cis caused to open trip bar46causes vertical break trip arm28to move to actuate the vacuum interrupter24. The trip arm28and trip bar46are also shown clearly by reference toFIG. 5.FIG. 6also shows trip arms28,27aand27band trip bars44aand44b.

As mentioned, utilizing the hybrid torsional-push-pull arrangement of the present invention to open and close switches16a,16b,16celiminates any problem with the prior art purely torsional drive “wind up” because there is now only push-pull motion between the phases ‘A’, ‘B’ and ‘C’ where accurate sequencing of phases is needed. Also, with the present invention the braces to support the triangular bracket of the prior art have been eliminated allowing for a smaller minimal distance or clearance between phases. Also, this reduced clearance comes about by the present invention, for the three-way switch configuration, that uses one vertical break switch located centrally between and at right angles to the two side break switches so that when the two side break switches open, there is electrical clearance to the vertical break switch parts. Also, by having the side break switch insulators having their axes in line or in the same plane as the axis of the vacuum interrupter24, further reduces the electric clearance necessary between phases. For example, by utilizing the present invention for a 115 kV installation the required spacing between phases is only 13 feet compared to 20 feet specified for the prior art arrangement described in the previously mentioned Turner Electric Corporation sales brochure, entitled “Air Break Switch 3D-D001, Teco Air Switches, 15 KV-161 KV”, as dimension “G” on the last page, copyright Turner Electric Corporation 1983. For such a 115 kV installation 13 feet is a typical minimal allowable safe clearance between phases. The present invention results in significant cost savings for the cost of the transmission pole and also results in a shorter unit which is unitized and can be shipped on a truck as a complete unitized unit. This complete unitized unit of the present invention also reduces the cost of installation, because the linkage between phases is factory adjusted instead of field adjusted.

A two-way switch assembly is shown inFIG. 7which has the same advantages as described for the three-way switch assembly ofFIG. 3, but only two side break switches16a,16bare necessary; no vertical break switch is required. The third transmission line conductor40dead-ends to the pole and is jumpered to the one end29aof vacuum interrupter24instead of the hinge end80cof the not needed vertical break switch16c. This allows current from third transmission line conductor40to be routed to either first transmission line conductor30or second transmission line conductor31depending on the open or closed position of the switches16aor16b.