Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
  • H01H33/02—Details
  • H01H33/04—Means for extinguishing or preventing arc between current-carrying parts
  • H01H33/12—Auxiliary contacts on to which the arc is transferred from the main contacts
  • H01H33/121—Load break switches
  • H01H33/122—Load break switches both breaker and sectionaliser being enclosed, e.g. in SF6-filled container
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H1/00—Contacts
  • H01H1/0015—Means for testing or for inspecting contacts, e.g. wear indicator
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/02—Bases, casings, or covers
  • H01H2009/0292—Transparent window or opening, e.g. for allowing visual inspection of contact position or contact condition

Definitions

• the present invention relates to a gas-insulated switchgear device for high- or medium- voltage applications, i.e. for applications with nominal operating voltages above 1000V, having improved functions and characteristics. Further, the present invention relates also to an electric power station or substation comprising such a gas-insulated switchgear device. It is well known in the art that along the path of a power grid there are provided several electric substations for transmitting and distributing electricity from a power generating source to loads and users connected to the feeding grid; these substations may be configured according to different layouts depending on the applications, and are realized by using a series of electric components, such as disconnectors, circuit breakers, instrument transformers, control systems.
• electric substations are realized by using several components which are structurally independent and suitably connected to each other and to the power line when assembling in order to obtain the required layout and to perform each a respective dedicated function;
• these traditional solutions have presented some drawbacks in practical use, mainly due to the large number of components required, even for providing a minimal configuration, and to their structural and functional separation. Indeed, these aspects result in heavy maintenance requirements for each and any of the components used, and to a considerable increase of the overall dimensions of the substation, with a consequent negative impact on installation and maintenance costs, as well as on environmental impact.
• these new devices comprise an external casing on which there are mounted two or three bushings each containing a corresponding electric terminal for input/output connections with a power line and/or other elements of the substation; inside the casing there are normally provided one or more disconnection units and one or more interruption units, which are electrically connected to each other and to the electric terminals, in such a way that electrical disconnection and/or circuit breaker maneuvers are performed in a coordinated way.
• switchgear devices has significantly contributed to reduce the number of components needed, thus allowing to realize more compact substations with less environmental visual impact, and to reduce installation and maintenance costs.
• a gas-insulated switchgear device of the present invention as defined in the appended claims.
• the present invention also provides an electric station or substation comprising such a gas-insulated switchgear device and more particularly a wind power generation station having a wind tower which houses such a gas-insulated switchgear device.
• figure 1 is a side view illustrating an embodiment of a pole of the gas-insulated switchgear device according to the invention
• figure 2 is a partial cross-section view of the switchgear device of figure 1
• figure 3 illustrates in greater details part of the portion circled of figure 2
• figure 4 is a view schematically illustrating another embodiment of a pole of the gas- insulated switchgear device according to the invention
• figure 5 is a perspective view showing the gas-insulated switchgear device according to the invention seen from the front in a three-pole configuration
• figure 6 is a perspective view showing the gas-insulated switchgear device of figure 5 seen from the back
• figure 7 is a perspective view schematically illustrating part of the base of a supporting structure used in the switchgear device according to the invention coupled with a hinge device
• figure 8 shows the device of figure 5
• the high- or medium-voltage gas-insulated switchgear device comprises a supporting structure globally indicated by the reference number 300 and one or more poles, e.g. three poles as shown in the appended figures.
• the number of poles can be modified according to the application.
• the supporting structure 300 comprises a plurality of members, for example U- or C or L shaped metallic elements, which are assembled to each other, e.g. by soldering, or screwing, or both.
• the profiled assembled elements define a frame having a base 301 adapted for placement on a supporting surface 302, such as a pavement, a concrete pad, another metallic base, land or any other suitable placement surface.
• the assembled members define at least one surface for mechanical connection with the one or more poles in the way that will be further described hereinafter.
• the assembled profiled members of the supporting structure 300 in addition to the base 301, define also a lateral wall or side 303 and a main or front side or wall 304.
• the base 301 comprises for example two parallel profiled members 310 which are connected at one side by a profiled cross member 306.
• the lateral side 303 is formed for example by two vertical uprights 305 and 307 which are connected to each other by some profiled cross members 306, e.g. four, and are connected each at a corresponding end of the two members 310.
• the upright 307 is part of the front wall 304 which further comprises a third upright 308.
• the uprights 307 and 308 are connected to each other by one of the members 310 and by some profiled members 311, 312, 313 which are spaced apart from each other and from said one member 310.
• One or more of the profiled members 311, 312, 313, for example at least the member 311 has a substantially flat surface provided with holes 314.
• each pole comprises a first fixed casing 1 which can be realized in one single piece or more pieces connected together and is partially or totally filled with an electric insulating gas, e.g. SF ⁇ , and extends along a longitudinal axis .
• the casing 1 houses at least a first terminal or bar 5 for electrical input/output connections of the switchgear device with a power line and/or other electrical equipments, such as transformers, loads, et cetera.
• the switchgear device according to the invention comprises a second terminal 6 for input/output connection.
• the switchgear device when for example the switchgear device is devised to realize a layout of the so-called double bus-bars type, it comprises a third terminal 70 for input/output connection, as schematically shown in figure 4.
• the connections between each terminal and the associated component e.g. the power line or any other electric equipment, such as a power transformer, can be realized by means of bushings which are connected to the pod- shaped portion 2 of the casing 1 and house the connecting conductors, or cables 201 or both.
• the connecting conductors, or cables 201 or both for example, in the embodiments of figures 1, 2 and 4, for each terminal 5, 6 and 70 there is provided a corresponding bushing, 3, 4 and 7, respectively.
• one of the input/output connections is realized by using a cable 201, and another connection is realized using a bushing 3.
• all connections are realized by using cables 201.
• the disconnector unit Inside the casing 1 there is a disconnector unit having at least a first fixed contact 8 electrically coupled to the first terminal 5, and a corresponding first movable contact 9 which can be actuated, during operation of said disconnector unit, so as to electrically connect/disconnect with/from the first fixed contact 8; in the embodiments illustrated, the disconnector unit preferably comprises also a second fixed contact 14 electrically coupled to the second terminal 6 and a corresponding second movable contact 15. According to the embodiment illustrated in figure 4, the disconnector unit comprises a third fixed contact 71 which is operatively connected to the corresponding third terminal 70; accordingly, the disconnector unit comprises a third movable contact 72 which can be electrically connected/disconnected with/from the third fixed contact 71.
• the disconnector unit can have the second movable contact 15 which can be suitably arranged so that it can be electrically connected/disconnected either with/from the second fixed contact 14 and also with/from the third fixed contact 71.
• the disconnector unit preferably comprises one or more additional fixed earth contacts, e.g. a first 40, a second 41 and a third earth contact 42 mounted on the inner surface of the first casing 1 which is at ground potential; during operations each earth contact 40, 41, 42 can be connected to a corresponding moving contact 9 or 15 or 72 so as to realize ground or earth connections.
• Some of or all the earth contacts 40, 41, 42 can be placed inside the main part of the casing 1, e.g.
• a circuit breaker unit which is electrically connected to the disconnector unit and comprises at least a couple of interruption contacts, i.e.
• a first main contact 10 and a second main contact 11 which, during operation of the circuit breaker unit, can be actuated along a longitudinal reference axis 200, which in practice may preferably coincide or be parallel with the longitudinal axis of the casing 1, between a circuit breaker closed position where they are electrically coupled and a circuit breaker open position, illustrated in figure 2, where they are electrically separated.
• the circuit breaker unit comprises also arcing contacts 12 and 13 whose structure and functions are well known in the art and therefore not described here in details.
• each pole is mounted on the supporting structure 300 with its longitudinal reference axis 200 transversal, more preferably vertical i.e. perpendicular, relative to the supporting surface 302.
• the supporting structure 300 features at said base 301 a bearing device which comprises a couple of elements 315, e.g. L-shaped, which extend upwardly from the members 310 of the base, and are connected to each other by a flat plate 316 which extends transversally relative to the reference axis 200.
• the elements 315 can be differently profiled, and the plate 316 can be realized in two or more pieces.
• the flat plate 316 is close to and transversal, preferably substantially perpendicular, relative to the flat surface of the profiled member 311.
• a corresponding bearing device For each pole there is provided a corresponding bearing device.
• the first casing 1 is removably connected to the profiled member 311, e.g. by screwing into the respective holes 314.
• the first casing 1 comprises an outward protrusion 110 which is connected to a corresponding flat surface of a second profiled member, i.e. the member 312 of the front wall. Also in this case the protrusion 110 can be screwed into the corresponding holes 314.
• the first casing 1 comprises at least a first porthole 120 for visually checking the position of the first movable contact 9; preferably, the first casing 1 also comprises a second porthole 121 which is spaced apart from the first porthole 120 for visually checking the position of the second movable contact 15.
• the first casing 1 may be provided with a third porthole, similar to the portholes 120, 121, for visually checking the position of the third movable contact 72.
• each of the earth contacts 40, 41 and 42 for earth connection with the corresponding movable contact 9, 15, 72 is positioned internally on the first casing 1 in such a way that it is visible from outside the first casing 1 through the corresponding porthole 120, 121.
• each porthole 120, 121 and the corresponding terminals 5, 6, 70 are positioned on the casing 1 substantially opposite to each other with respect to the reference axis 200, i.e. they are positioned relative to each other so that when the pole is mounted on the supporting structure 300, they face towards opposite directions with respect to the front side 304.
• all poles are mounted on the supporting structure 300, they are positioned substantially vertically and side by side with their respective longitudinal axes 200 lying on a common vertical plane; all portholes 120, 121, are positioned on one half plane, while the terminals for input/output connections are placed on the opposite half plane relative to said common plane.
• the second porthole 121 will allow visual inspection of the second and third movable contacts 15, 72 as well as of the second and third earth contacts 41 and 42. Also in this case, the second porthole 121 is positioned opposite to the second and third terminals 6, 70 relative to the reference longitudinal axis 200.
• the switchgear device further comprises: actuating means for operating the disconnection unit and the circuit breaker unit when executing electrical manoeuvres, e.g. opening/closing of the circuit breaker unit and/or connection/disconnection of the input/output connections; and a second casing unit, globally indicated in figure 1 by the reference number 100, which is operative Iy coupled with said actuating means, which houses the contacts of the circuit breaker unit and on the outer surface of which at least the first movable contact 9 is mounted.
• the second casing 100 is filled with insulating gas, e.g. SF ⁇ ; alternatively, it is possible to fill with a first insulating gas having high dielectric properties, e.g.
• the second casing 100 which can be hermetically sealed, and to fill the remaining internal volume of the first casing 1 with air or other suitable insulating gases, such as nitrogen (N2), nobles gases, or mixtures.
• the second casing 100 is formed by several pieces solidly connected to each other and forming a unique rotating body; in particular, as illustrated in figures 1-2, its structure advantageously comprises the interruption chamber 101 of the circuit breaker unit which in turn can be formed by one or more pieces solidly connected to each other, an electric shield 102 which is preferably mounted close to a first end of the interruption chamber 101, and a hollow rotating supporting member 103.
• the second casing 100 is operatively connected to the opposite ends of the first casing 1 by means of rotating shaft means shaft 105 and said member 103 which are connected to the casing 1 by using suitable systems, e.g. bearings, flanges etc.
• the second casing 100 is preferably pivotally mounted inside the first casing 1 and is operatively coupled to the actuation means so as, when the disconnection unit is operated by the actuating means, it rotates dragging into rotation at least the first movable contact 9, substantially solidly with it; preferably, also the second movable contact 15 and when present also the third movable contact 72 are mounted on the second casing 100, and rigidly rotate with it so that they can be electrically connected/disconnected with/from the corresponding fixed contact(s) 14 (71) during operation of the disconnector unit.
• the actuating means are configured and operatively coupled to the couple of main interruption contacts 10-11 and also to the second casing 100 which in practice acts as and constitutes an actuating means as well- in such a way that, when the second casing 100 rotates during operation of the disconnection unit, the main interruption contacts 10-11 remain electrically coupled in the circuit breaker closed position and substantially still relative to each other, i.e. they do not have movement relative to each other (apart from unavoidable mechanical inertia).
• the couple of interruption contacts 10 and 11 are operatively coupled to the actuating means so as to rotate, during rotation of the second casing 100, about the reference longitudinal axis 200, substantially simultaneously to each other (apart from initial unavoidable mechanical inertia), i.e. with the same angular speed, while being electrically coupled in the circuit breaker closed position, and to translate one relative to the other along the longitudinal axis 200 with the casing 100 kept still, during closing/opening operation of the circuit breaker unit.
• the couple of main interruption contacts 10 and 11 are operatively coupled to the actuating means so as to rotate, during rotation of the second casing 100, substantially simultaneously to each other and together with the second casing 100 (apart from initial mechanical inertia).
• the first main contact 10 is solidly connected to the second casing 100 and the actuation means comprise: rotating shaft means, comprising the rotating shaft 105, which are connected to the second casing 100 and are operatively coupled with driving means, e.g.
• a motor positioned outside the first casing 1, schematically indicated in figure 1 by the reference number 106; and rod-shaped means which comprise a first rod portion 16, for example made of electrically conducting material, which is connected to and supports the main contact 11, and a second rod portion 17, for example made of electrically insulating material, which protrudes outside the first casing 1 and is operatively connected to driving means 107, e.g. another motor.
• driving means 107 e.g. another motor.
• the motors 106 and 107 are connected to the supporting structure 300 at the end portions of the lateral side 303.
• the first rod 16 portion and the main contact 11 may be realized in a unique piece made of electrically conducting material.
• the two portions 16 and 17 are substantially aligned along the longitudinal axis 200 and are operatively connected to each other and to the second casing 100 by suitable coupling means; as illustrated in figures 2-3 said coupling means comprise a first bush 18 which is positioned around facing ends of the first and second rod portions 16-17, and is connected to a first end of the second casing 100.
• the bush element 18 is connected to the internal side of the electric shield 102 by interposing sealing means 19, e.g. a ring made of teflon.
• the coupling means comprise also a first shaped element 20 which is inserted in the first rod portion 16 at an end thereof, and is provided with a first through hole 21 and a second through hole 22 which are arranged transversally with respect to the longitudinal axis 200; preferably, the shaped element 20 has also a contoured head 35 adapted to obstruct an opening 36 provided on the first rod portion 16.
• the coupling means further comprise: a first pin 23 which passes inside the first through hole 21 and a corresponding hole of the rod portion 16, and is fitted in a receiving seat provided on the first bush 18; a second pin 24 which passes within the second through hole 22 and is fitted inside a receiving seat provided on the first rod portion 16.
• the pins 23 and 24 allow realizing rigid couplings among the bush element 18, the first rod portion 16, and the shaped element 20.
• a first hollow tube 25 which is positioned, along the longitudinal axis 200, inside the second rod portion 17 and at an end thereof;
• a second hollow tube 26 which is also positioned inside the second rod portion 17 around the first tube 25, and is provided with a through channel 27 extending transversally with respect to the axis 200;
• a coupling pin 28 which is inserted inside said through channel 27 and is fitted in a seat arranged on the second rod portion 17; the coupling pin 28 has a through opening, directed along the axis 200, receiving the first hollow tube 25.
• a fixing a element e.g.
• a screw 29 which passes through the first tube 25, and has a first end portion 30 which is fixed, e.g. screwed onto the first shaped element 20, and a head portion 31 which, by the fixing, is brought to push the first tube 25 in abutment against the first shaped element 20.
• the operative coupling between the various components is realized so as, when fixing is completed, there is a suitable small clearance between: the second tube 26 and the first tube 25; the facing surfaces of the second tube 26 and the first shaped element 20-the first rod portion 16; the head portion 31 and the second tube 26.
• the device according to the invention there is a unique motor 106 which is connected to and contemporaneously drives all the disconnection units of the various poles used.
• the motor 106 is operatively connected to the shaft 105 of each pole disconnection unit by means of a modular rod 130, constituted for example by pieces of a tubular element assembled to each other.
• a unique motor 107 which is connected to and contemporaneously drives all breaker units of the various poles used.
• the motor 107 is operatively connected to the rod 17 of each pole by means of a modular rod 140, constituted for example by pieces of a tubular element assembled to each other.
• the supporting structure 300 can be provided with a hinge device 320 illustrated in figure 7.
• the hinge device comprises for example a U-shaped element 321 which is fixed to a profiled member 310 of the base 301 and a rod 322 which passes through the lateral side of the U-shaped element 321 and enters into corresponding holes provided in the two members 315 of a bearing device.
• a pulley (schematically indicated in figure 8 by the reference number 501)can be coupled to the supporting structure in order to hold the pole.
• the screws connecting the elements 315 of the corresponding bearing device are unscrewed from the member 320; in this way, once the screws connecting the casing 1 to the profiled members 311 and 312 are also unscrewed, the pole can be rotated thanks to the hinge device and can be extracted from the supporting frame 300.
• a profiled track connected to the U-shaped element 321 so as to make the pole sliding along it.
• the circuit breaker unit In practice, in normal working conditions, the circuit breaker unit is in a closed position with the contacts 10-11 electrically coupled; each of the movable contacts of the disconnector unit is connected to the corresponding fixed contact, so as all input/output connections are closed.
• the driving means 107 drive the second rod portion 17; the second rod portion 17 translates along the axis 200, (arrow 50 in figure 2) and, thanks to the couplings above described, it drags in joint translation with it: the screw 29, the tubes 25-26, the coupling pin 28, the two pins 23-24, the shaped element 20, the bush 18 (which slides on the inner surface of the sealing means 19) the first rod 16, and the second main contact 11 connected to the rod portion 16 which moves away from the first main contact 10; with respect to the second casing 100-first main contact 10-shaft means 105 which instead remain substantially still.
• the shaped head 35 is advantageously positioned so as to obstruct the opening 36 thus preventing flowing of the hot gases produced following the opening operation towards the insulating second rod portion 17, and convey such gases in a suitable quenching zone inside the casing 100.
• Closing of the circuit breaker occurs in an analogous way with the same components jointly translating in the opposite direction (arrow 60 in figure 2).
• the drive means 106 drive the shaft means, and in particular the shaft 105 which rotates, around the axis 200, jointly with: the casing 100, the couple of contacts 10-11 (which remain electrically coupled), the sealing means 19, the bush 18, the shaped element 20, the pins 23-24, the first rod portion 16, the screw 30 and the first tube 25; while the second tube 26, the coupling pin 28 and the second rod portion 17 are maintained substantially still.
• the second casing 100 drags into rotation the movable contact(s) 9(15,72) of the disconnector unit mounted thereon.
• the couple of interruption contacts 10 and 11 are operatively coupled to the actuating means so as, during rotation of the second casing 100, they are kept still, i.e. motionless, and electrically coupled in the circuit breaker closed position, while they translate relatively to each other along the axis 200 during opening/closing operations of said circuit breaker unit while the second casing 100 is kept substantially still.
• the first main contact 10 (as well as the arcing contact 12) is mounted on a suitable supporting member, schematically indicated in figure 2 by the number 108, which is operatively coupled to the casing 100, e.g.
• the second main contact 11 is connected to rod- shaped means, constituted for example a single rod-shaped body, or comprising two separate rod portions rigidly coupled to each other, e.g. the two rod portions 16-17 of the previous embodiment.
• the coupling means are configured so as to mechanically connect the second casing 100 on one side with the main contact 10 and the shaft means, and on the other side with the rod-shaped means by realizing a turning kinematic pair during rotation of the second casing 100, and by realizing a sliding kinematic pair during operation of the circuit breaker unit.
• said coupling means may comprise at least a thrust bearing; preferably there are provided two thrust bearings, schematically indicated in figure 1 by boxes in dotted lines 80-90, which are positioned for example one inside the electric shield 102 and the other at the opposite end of the first casing 100 at the region where the supporting member 108 is coupled to the casing 100.
• the driving means 107 when executing opening/closing of the circuit breaker, the driving means 107 drive the rod shaped means which translate along the axis 200 and inside the bearing 90 together with the second main contact 11 which moves away from the first contact 10; the first contact 10 and the casing 100 remain still (sliding cinematic pair with respect to the casing 100).
• the drive means 106 When operating the disconnector unit, the drive means 106 drive the shaft 105 which rotates together with the casing 100 around the axis 200, while, thanks to the thrust bearings 80-90, the contacts 10- 11, the supporting member 108 operatively connected to the casing 100 through the bearing 80, and the rod shaped means remain still with the contacts 10-11 electrically coupled in the circuit breaker closed position (turning cinematic pair of the casing 100 with respect to the ensemble contacts 10-11 -rod shaped means-shaft means).
• possible alternative embodiments may be used as regard to the configuration and of disconnection unit and/or of the circuit breaker unit, and/or their mutual coupling, and also as regard to the positioning and actuation of their contacts.
• the second casing 100 can be realized in separate pieces not rigidly rotating all together.
• the gas-insulated switchgear device according to the present invention is particularly suitable for realizing several different types of electric power stations or substations.
• the present invention also relates to an electric power station or substation which is suitable to be connected to a power line characterized in that it comprises a gas-insulated switchgear device as previously described and claimed.
• figures 10 and 11 show an electric substation comprising a switchgear device according to the invention wherein each pole has a first terminal electrically connected to a power transformer 400 by using a corresponding bushing 3 and a second terminal connected to a power line or to another electrical equipment by using a cable 201.
• the first terminal can be connected to the power transformer 400 (or any other electrical equipment) by using a cable 201, as for example schematically represented in figure 13.
• the gas-insulated switchgear device, and if desired also the transformer 400 can be positioned inside a container 401; this embodiment is particularly useful when the station or substation is placed in an aggressive environment, e.g. in a desert.
• the gas- insulated switchgear device is positioned at a distance from and with the terminals of each poles facing the transformer 400; a first protecting net or fence 402 and a second protecting net or fence 403 are positioned at the respective sides of and run from the gas-insulated switchgear device up to the transformer 400.
• the two fences 402 and 403 laterally delimit an area inside which the electrical connections between the terminal of each pole and the power transformer 400 and the terminal of each pole and a power line or another electrical equipment are positioned and protected. In this way an operator can safely approach the switchgear device from the side where the portholes 102, 121 are provided and visually inspect the position of the disconnector movable contacts of each poles.
• the gas insulated switchgear device according to the invention is particularly suitable for use in wind power generation station where wind towers are used.
• the present invention also relates to a wing power generation station comprising at least one wind tower 500 and characterized in that it comprises a gas-insulated switchgear device as previously described and claimed which is positioned inside the tower 500 as for example schematically illustrated in figure 12.
• the switchgear device thus conceived is susceptible of modifications and variations, all of which are within the scope of the inventive concept, all the details may further be replaced with other technically equivalent elements provided they are suitable to perform the required function.
• the supporting structure can be formed by differently- shaped profiled elements, or others elements such as tubes, or pieces obtained by casting, et cetera;
• the motors 106 and 107, and where necessary also the relative connection means with the poles, can be placed in other positions, for example vertical, horizontal or parallel relative to the plane on which the axes of the poles lie;
• the bearing device and/or the hinge device can be differently shaped, et cetera.
• the materials may be any according to the requirements and the state of the art.
• the gas-insulated switchgear device according to the invention fully provides the desired aim giving a number of significant advantages and improvements with respect to the prior art devices.

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Citations (5)

• 2008
  • 2008-03-17 CN CN200880009656.2A patent/CN101641755B/zh active Active
  • 2008-03-17 WO PCT/EP2008/053170 patent/WO2008119655A1/en active Application Filing
  • 2008-03-17 EP EP08717906.5A patent/EP2132757B1/en active Active

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