JP2012015009A - High voltage switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high voltage switchgear miniaturized by reducing an electric field in a blade end and a stator end and improving a voltage resistance property without using a larger shield.SOLUTION: A high voltage switchgear has a switchgear including: a movable side conductor 2 connected to one of bus conductors: a movable element 4 provided for each phase and made of a conductive member with one end side pivotally supported by the movable side conductor 2 in a rotatable manner; and insulating gas. The switchgear also has shields 7a and 7b in which a surface of each of shield electrodes 10c and 10d electrically and mechanically secured to the movable side conductor 2 is insulation-covered or molded with an insulator, and the shields 7a and 7b are each arranged to face a side surface of the movable element 4 at an opening position of the movable element 4.

Description

  The present invention relates to a high-voltage switchgear applied to a receiving / transforming facility, a substation, a switchgear, and the like.

  High-voltage switchgear that is configured by electrically connecting various switches such as circuit breaker (CB), disconnect switch (DS), ground switch (ES), etc. is highly reliable in order to provide stable power supply. In order to meet the needs of the world, there have been efforts to reduce the size and capacity of the device and improve safety. For example, in the case of a disconnecting switch and a grounding switch that do not require high current interrupting performance, the opening / closing speed may be low. Therefore, it is possible to open and close by combining the switch and combining the disconnecting switch and the grounding switch. Miniaturization of the entire apparatus has been attempted.

  In particular, the blade type that can share the movable element of the disconnecting switch and the earthing switch is suitable for miniaturization, but there is a problem that the electric field increases due to the electric field concentration at the end of the movable element or the stator. The use of insulating coatings and resin molds against these high electric fields has ensured the dielectric strength, and the high voltage switchgear has been miniaturized by shortening the insulation distance.

  For example, it is a blade type disconnector in which the movable element rotating shaft fixed end and the stator of the disconnector are covered with a substantially rectangular insulating tube, and U-shaped openings are provided on two opposing side surfaces of the insulating tube. At the same time, two rectangular plate electrodes are embedded in two side surfaces other than the side surface on which the U-shaped opening is formed so as to maintain a constant interval substantially in parallel (see Patent Document 1). That is, the flat plate electrode is covered with an insulating resin to form a composite insulating structure in which an insulating gas and solid insulation are combined, thereby improving the dielectric strength and withstand voltage performance and reducing the size of the disconnector.

  In order to further reduce the size, the shield with insulation coating on the mover and the stator is bolted, and a withstand voltage of triple junction is ensured by ensuring a gap of 1 mm or more between the mover and the shield. A structure for preventing the reduction has been proposed (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 11-252721 JP 2006-216448 A

  Since the conventional technique of Patent Document 1 has a structure including an insulating cylinder as an element, there is a problem that a conductor is necessarily arranged in the shield, and the shield becomes large. In addition, there is a need for a space for the mover to enter between the stator and the shield, and there is a problem that the shape of the shield must be increased in order to reduce the electric field of the stator.

  In the prior art of Patent Document 2, since the movable element and the movable shield arranged on the side surface move together, there is an interval for the movable shield to enter between the stator and the fixed shield in addition to the movable element. This is necessary, and there is a problem that the fixed shield shape has to be made larger. In addition, since the fixed shield must be placed outside the movable shield, the space between the ground and the phase is necessary to secure a gas gap between the fixed shield and the tank or other phase fixed shield. Therefore, there is a problem that the size of the entire switch is hindered.

  The present invention has been made based on the above matters, and its purpose is to improve the withstand voltage performance by relaxing the electric field at the blade end and the stator end without increasing the size of the shield. The present invention provides a high voltage switchgear that is miniaturized.

  In order to achieve the above-mentioned object, the first invention is provided for each phase comprising a movable conductor connected to one bus conductor and a conductor member pivotally supported at one end of the movable conductor. In a high-voltage switchgear having a switch provided with one mover and an insulating gas, the surface of the shield electrode fixed electrically and mechanically to the movable conductor is molded with an insulation coating or an insulator. The switch is provided with a shield formed in such a manner that the shield is disposed so as to face the side surface of the mover at the opening position of the mover.

  Further, the second invention uses the switch formed in the first invention such that the distance between the shields is narrower on the tip side of the shield than on the fixed side to the movable conductor. It is characterized by.

  Furthermore, a third invention is the first or second invention, wherein the shield electrode is mechanically fixed to the movable conductor via an insulator, and the potential of the shield electrode is lower than that of the movable conductor. A switch configured as described above is used.

  According to the present invention, since the withstand voltage performance of the blade type switch can be improved while reducing the size of the shield shape, it is possible to provide a high voltage switchgear that is smaller than the conventional one.

It is a top view which shows the disconnector which comprises 1st Embodiment of the high voltage switchgear of this invention. It is sectional drawing which looked at the disconnector shown in FIG. 1 from the II-II arrow. It is a perspective view which shows the movable side shield of the disconnector which comprises 1st Embodiment of the high voltage switchgear of this invention. It is a top view which shows the disconnector which comprises 2nd Embodiment of the high voltage switchgear of this invention. It is sectional drawing which looked at the disconnector shown in FIG. 4 from the VV arrow. It is a conceptual diagram explaining the electric potential of the shield electrode in 2nd Embodiment of the high voltage switchgear of this invention. It is a schematic side view which shows the structure of 3rd Embodiment of the high voltage switchgear of this invention.

  Hereinafter, embodiments of a high-voltage switchgear according to the present invention will be described with reference to the drawings.

  1 to 3 show a first embodiment of a high-voltage switchgear according to the present invention, and FIG. 1 is a plan view showing a disconnector constituting the first embodiment of the high-voltage switchgear according to the present invention. FIG. 2 is a cross-sectional view of the disconnector shown in FIG. 1 as viewed from the direction of arrows II-II, and FIG. 3 is a movable side shield of the disconnector constituting the first embodiment of the high-voltage switchgear according to the present invention. It is a perspective view shown.

  FIG. 1 is a plan view of an example of a blade-type disconnector disposed between a fixed-side conductor 1 and a movable-side conductor 2 in which a disconnector and a grounding switch are combined. Only the part between the poles of the disconnector is shown, and the fixed side of the tank and the ground switch, the drive system of the insulating rod, etc. are not shown. The embodiment of the present invention is characterized in that shields each having a shield electrode surface molded with an insulating coating or an insulator are arranged on both sides of the stator and on both sides of the mover in an open state.

  As these insulating coating materials and insulators, for example, epoxy resin, oxide film, PTF, silicone rubber, filled epoxy resin, etc. are used, and SF6, air, N2, CO2, N2 are used in the atmosphere of the disconnecting switch. / Insulating gas such as SF6 mixed gas is filled.

  In FIG. 1, the disconnector is, for example, a movable side conductor 2 that is electrically connected to one bus conductor (not shown), and one piece that is pivotally supported on the movable side conductor 2 by a rotary shaft 8 at one end side. , A fixed-side conductor 1 that is electrically connected to the other bus conductor (not shown), and the other end side of the movable element 4 that is electrically connected to the fixed-side conductor 1 ( And stators 3a and 3b arranged so as to be in contact with and away from the outer surface on the front end side.

  On both outer sides in the horizontal direction of the stators 3a and 3b, fixed-side shields 6a and 6b are respectively provided in which the surfaces of the shield electrodes 10a and 10b are molded with an insulating coating or an insulator.

  As shown in FIG. 1, the fixed-side shields 6a and 6b are respectively fixed by providing stators 3a and 3b and a gap G1. The shield electrodes 10a and 10b indicated by broken lines are electrically and mechanically fixed to the fixed-side conductor 1, respectively.

  As shown in FIG. 2, the movable shields 7 a and 7 b are fixed at one end to the movable conductor 2, and the shield electrodes 10 c and 10 d shown by broken lines are fixed electrically and mechanically to the movable conductor 2, respectively. Has been. Although the movable element 4 is pivotally supported by the movable conductor 2, the movable shields 7a and 7b are fixed so as not to rotate.

  The movable shields 7a and 7b are fixed so as to be the gap G2 shown in FIG. 1 when the movable element 4 is positioned at the fixed position.

  The movable shields 7a and 7b are formed so that the gap between the movable shields 7a and 7b is narrower at the tip side of the movable shields 7a and 7b than the portion fixed to the movable conductor 2.

  As shown in FIG. 2, the rotary shaft 8 of the mover 4 has a substantially quadrangular prism shape in cross section. A square hole slightly larger than the cross section of the rotating shaft 8 is provided in the penetrating portion of the rotating shaft 8 in the movable element 4, so that the movable element 4 is centered on the rotating shaft 8 when the rotating shaft 8 rotates. Can be rotated. As a result, the closing operation of the disconnector and the closing operation of the ground switch can be performed.

  2 is a cross-sectional view of the disconnector shown in FIG. 1 as viewed from the direction of arrows II-II. In FIG. 2, the fixed side of the ground switch is also shown. In the upper right side of FIG. 2, a grounding conductor 9 that is electrically connected to a grounding wire (not shown), and a grounding conductor 9 that is electrically connected to the outer surface on the other end side (front end side) of the mover 4, respectively. Stators 3c and 3d arranged so as to be separated from each other, and fixed shields 6c and 6d formed by molding the surfaces of shield electrodes on the outer sides in the horizontal direction of the stators 3c and 3d with an insulating coating or an insulator. I have.

  By rotating the rotating shaft 8 clockwise or counterclockwise, the mover 4 is driven in the direction of any arrow. FIG. 2 shows a case where both the disconnect switch and the ground switch are open. If the mover 4 is driven counterclockwise to make the mover 4 substantially horizontal, the mover 4 and the stator 3a are electrically connected, the disconnecting switch is closed, and the ground switch is opened. It becomes a pole state.

  On the other hand, if the mover 4 is driven clockwise to make the mover 4 substantially vertical, the mover 4 and the stator 3c of the earthing switch are electrically connected, and the disconnecting switch is opened and the earthing switch is opened. Is closed. By comprising in this way, a disconnector and a grounding switch can be compounded and the needle | mover 4 can be shared.

  In the switch according to the present embodiment, the insulation performance related to the withstand voltage is most severe when the disconnecting switch and the grounding switch shown in FIG. 2 are both open. At this time, the fixed-side shields 6a, 6b, 6c, 6d and the movable-side shields 7a, 7b are formed in the same size or larger than the stators 3a, 3b, 3c, 3d and the mover 4, respectively. The electric field of the child 3a, 3b, 3c, 3d and the mover 4 can be greatly reduced.

  Further, the stators 3a, 3b, 3c, 3d and the movable element 4 and the respective shields 6a, 6b, 6c, 6d, 7a, 7b can be arranged with a gap of about several mm, and the shields The shape can be made smaller than before.

  FIG. 3 is a perspective view showing the movable side shields 7a and 7b of the disconnector. As shown in FIG. 3, substantially hemispherical portions 7 </ b> R are formed in the portions where the electric fields on the distal ends of the movable shields 7 a and 7 b are increased. As a result, in addition to the effect of increasing the curvature, the shield surface electric field can be further reduced by the action of the dielectric relaxation effect by increasing the thickness of the insulator. Although not shown in the figure, the tip of the fixed side shield can be formed in the same shape, so that the disconnector / grounding switch can be greatly reduced in size by the same effect.

  According to the first embodiment of the high-voltage switchgear of the present invention described above, the withstand voltage performance of the blade type switch can be improved while reducing the size of the shield shape. Thus, a high voltage switchgear can be provided.

  Further, according to the first embodiment of the high-voltage switchgear of the present invention described above, since the gaps G1 and G2 are provided, it is possible to prevent the formation of a triple junction where the insulator / electrode / insulating gas intersect. It is possible to prevent the breakdown voltage performance from degrading or the breakdown voltage performance from becoming unstable, and to prevent the discharge along the shield surface from progressing to the stators 3a, 3b, 3c, 3d and the mover 4. is there.

  Further, according to the first embodiment of the high-voltage switchgear of the present invention described above, the substantially hemispherical portion 7R is formed in the portion where the electric field on the tip side of the movable shields 7a and 7b is increased. The surface electric field can be reduced and the disconnector / grounding switch can be greatly downsized.

  In addition, when adopting a structure having two movable elements 4 as in the prior art, the stator has a single structure so as to be sandwiched between the two movable elements, and a fixed-side shield that relaxes the electric field of the stator. Since it is indispensable to widen the distance from the stator beyond the size that the mover can pass through, the shield on the movable side must be enlarged. Further, in a horizontal single-row three-phase structure or the like, the mover is arranged outside the stator, and the fixed shield is arranged outside the stator, so that the fixed shield interval between the phases is narrowed. For this reason, it becomes necessary to lengthen the interphase distance, and it becomes necessary to increase the size of the disconnector / ground switch. In the present embodiment, advantageous effects can be obtained also from these viewpoints.

  4 to 6 show a second embodiment of the high-voltage switchgear according to the present invention, and FIG. 4 is a plan view showing the disconnector constituting the second embodiment of the high-voltage switchgear according to the present invention. 5 is a cross-sectional view of the disconnector shown in FIG. 4 as viewed from the direction of arrows V-V. FIG. 6 is a conceptual diagram for explaining the potential of the shield electrode in the second embodiment of the high-voltage switchgear according to the present invention. It is. 4 to 6, the same reference numerals as those shown in FIGS. 1 to 3 are the same or corresponding parts, and the description thereof is omitted.

The disconnector shown in FIGS. 4 and 5 is different from the disconnector of the first embodiment shown in FIGS. 1 and 2 in the following points.
(1) As shown in FIG. 4, the fixed-side shields 6a and 6b are mechanically fixed to the fixed-side conductor 1 with insulating screws 11a and 11b, respectively, by providing stators 3a and 3b and a gap G1. . The shield electrodes 10a and 10b indicated by broken lines are insulated from the fixed conductor 1 without being electrically connected to each other.
(2) As shown in FIG. 4, the movable shields 7a and 7b are mechanically fixed at one end to the movable conductor 2 with insulating screws 11c and 11d, respectively. Further, the shield electrodes 10c and 10d shown by broken lines are insulated from the movable conductor 2 without being electrically connected to each other.

First, the potential of the shield electrode 10b will be described with reference to FIG. When the potential V1 of the shield electrode 10b is the voltage V of the fixed-side conductor 1, the capacitance C1 between the fixed-side conductor 1 and the stator 3b and the shield electrode 10b, the shield electrode 10b and the ground electrode (for example, ground) V1 = V × C2 / (C1 + C2), which is a voltage corresponding to the capacitance ratio with the floating capacitance C2 between the containers.
Therefore, the potential V1 of the shield electrodes 10a and 10b is lower than the voltage V of the fixed-side conductor 1. Therefore, the electric field generated on the surfaces of the fixed shields 6a and 6b is reduced, and the ground insulation performance can be improved as compared with the case of the first embodiment shown in FIG. The same applies to the movable shields 7a and 7b shown in FIG.

  On the other hand, for example, in the fixed shields 6a and 6b, the voltage difference between the stators 3a and 3b is larger than that in the first embodiment shown in FIG. 1, so that the gas gaps G1 and G1 shown in FIG. It is often thought that G2 must be wider than in FIG. However, the fixed-side shields 6a and 6b and the stators 3a and 3b are provided with an interval of several millimeters in order to suppress an increase in electric field due to the triple junction, and if the differential voltage that can be covered within the gap range is designed, the movable element Or it is not necessary to widen the space | interval between a stator and a shield compared with the case of 1st Embodiment shown in FIG. 1, and size reduction is attained.

  In addition, when an insulating gas whose effective ionization coefficient has a gentler slope than that of SF6, such as air, N2, CO2, and N2 / SF6 mixed gas, the surface electric field of the ground potential is high in an unequal electric field. However, as the distance from the ground potential electrode increases, the increase in the number of electrons generated by the avalanche of the electron avalanche decreases remarkably, and the number of electrons decreases when the electric field in the gas space decreases and the effective ionization coefficient becomes negative. start. In other words, even if the surface electric field of the ground electrode is high, the progress of discharge stops and does not lead to dielectric breakdown, and the withstand voltage performance depends only on the surface electric field of the high voltage electrode. This structure of the blade type switch is an unequal electric field, and the fixed side of the ground switch is always at the ground potential. Therefore, when the insulating gas is used, the electric field of the stator of the ground switch is reduced. The shield can be omitted.

  According to the second embodiment of the high-voltage switchgear of the present invention described above, the same effects as those of the first embodiment described above can be obtained.

  Further, according to the second embodiment of the high-voltage switchgear of the present invention described above, the insulation reliability is maintained or improved by the improvement of the insulation performance with respect to the ground, the phase and the inter-pole direction and the effect of parts sharing / reducing parts. However, the high-voltage switchgear can be made smaller than before.

  In addition to the metal such as aluminum, copper, stainless steel and iron for the shield electrode, the same effect can be expected even when a conductive resin is used. When conductive resin is used, the linear expansion coefficient with the dielectric on the shield surface can be reduced, and the shield can be made thinner and lighter than when metal is used.

  FIG. 7 shows a third embodiment of the high voltage switchgear according to the present invention, and is a schematic side view showing the configuration of the third embodiment of the high voltage switchgear according to the present invention. In FIG. 7, the same reference numerals as those shown in FIGS. 1 to 6 are the same or corresponding parts, and the description thereof is omitted.

  FIG. 7 shows an embodiment in which the high voltage switchgear according to the present invention is applied to a disconnect switch and a ground switch. It is one Example of the high voltage switch apparatus comprised combining the grounding container 20 with which insulating gas, such as SF6, air, N2, CO2, N2 / SF6 mixed gas, was enclosed.

  In FIG. 7, the high-voltage switchgear includes a first grounding container 20A filled with an insulating gas, a second grounding container 20B placed above the first grounding container 20A and filled with an insulating gas, The third grounding container 20C is disposed substantially behind the first grounding container 20A and is filled with an insulating gas.

  The first grounding container 20A accommodates the circuit breaker 21 therein to form a circuit breaker unit. The second grounding container 20B houses a disconnector corresponding to the busbar side and a composite device 22a of a grounding switch to constitute a busbar side disconnector unit. Further, the third grounding container 20C houses a disconnector corresponding to the line side and a composite device 22b of a grounding switch to constitute a line side disconnector unit. A bus unit having a bus 23 is connected to the bus-side disconnector unit. A cable 26 is connected to the line-side disconnector unit via a cable head 25.

  The bus unit described above is provided in the direction perpendicular to the upper surface of FIG. 7 and on the back side of the second ground container 20B, and includes a three-phase main bus conductor (not shown). Moreover, the bus-side disconnector unit described above includes a composite device 22a in which a disconnector and a ground switch are combined, and a conductor 15B that is connected to the conductor 12B of the circuit breaker unit via the central conductor of the insulating spacer 13B. Yes.

  The circuit breaker unit in which the circuit breaker 21 is disposed includes the circuit breaker 21, an insulating support member that fixes and supports the circuit breaker 21 to the first grounding container 20A, and the bus-side disconnector unit via the central conductor of the insulating spacer 13B. A conductor 12B connected to the conductor 15B and a conductor 12C connected to the conductor 15C of the line-side disconnector unit via the central conductor of the insulating spacer 13C are provided.

  The line-side disconnector unit includes a composite device 22b in which a disconnector and a ground switch are combined, a conductor 15C connected to the conductor 12C of the circuit breaker unit via the central conductor of the insulating spacer 13C, an arrester 24, and the like. Yes.

  The cable unit has a cable 26 led out from the line side disconnector unit via the conductor 16 and the cable head 25, and this cable 26 is connected to a load.

  Reference numeral 27 denotes another line (bus) such as a bypass circuit.

  In FIG. 7, the composite device 22 a in the bus-side disconnector unit connects the mover 4, which is a conductor extending upward in the drawing, to the stators 3 c and 3 d electrically connected to the ground conductor 9.

  On the other hand, stators 3a and 3b (not shown) that are electrically connected to the bus bar 23 are provided in the direction perpendicular to the paper surface and on the back side of the rotating shaft 8, and the movable element 4 of the composite device 22a is in the state shown in the figure. , The conductor 15B connected to the conductor 12B of the circuit breaker unit and the bus 23 can be electrically connected. In other words, in the composite device 22a, the conductor 15B extending upward in the drawing and the bus bar 23 arranged in the direction perpendicular to the paper surface in the bending position are brought into contact with and separated from each other by rotating the mover 4.

  The rotating shaft 8 is connected to the insulating rod 5 in the second grounding container 20B, and is rotated via the insulating rod 5 by an operating device (not shown) provided outside the second grounding container 20B.

  Further, the composite device 22b in the line-side disconnector unit connects the mover 4 which is a conductor extending downward in the figure to the stators 3c and 3d which are electrically connected to the ground conductor 9.

  On the other hand, the conductor 15C and the conductor 16 connected to the conductor 12C of the circuit breaker unit can be electrically connected by rotating the mover 4 of the composite unit 22b upward from the illustrated state. In other words, the composite unit 22b causes the conductor 15C connected to the conductor 12C of the circuit breaker unit extending in the horizontal direction and the conductor 16 rising in the vertical direction in the bent position relationship to move toward and away from each other by rotating the mover 4. Yes.

  The circuit breaker 21 may be either a gas circuit breaker or a vacuum circuit breaker.

  According to the third embodiment of the high-voltage switchgear of the present invention described above, the same effects as those of the first and second embodiments described above can be obtained, and a combination of a disconnect switch and a ground switch can be obtained. By arranging the current flow paths in the high-voltage switchgear at the portions of the devices 22a and 22b, the space efficiency of the device is improved. As a result, the high voltage switchgear can be further reduced in size / weight.

DESCRIPTION OF SYMBOLS 1 Fixed side conductor 2 Movable side conductor 3, 3a, 3b, 3c, 3d Stator 4, 4a, 4b Movable element 5 Insulating rod 6, 6a, 6b, 6c, 6d Fixed side shield 7, 7a, 7b Movable side shield 8 Rotating shaft 9 Grounding conductor 10 Shield electrode 11 Insulating screw 20 Grounding container 21 Breaker 22, 22a, 22b Combiner of disconnect switch and ground switch 23 Busbar 24 Lightning arrester 25 Cable head 26 Cable

Claims (3)

Opening / closing provided with a movable element connected to one bus bar conductor, one movable element for each phase composed of a conductive member pivotally supported at one end of the movable conductor, and an insulating gas In a high voltage switchgear having a device,
Provided with a shield formed by molding the surface of the shield electrode electrically and mechanically fixed to the movable side conductor with an insulating coating or insulator,
A high-voltage switchgear comprising a switch in which the shield is disposed so as to face the side surface of the mover at the opening position of the mover. The high voltage switchgear according to claim 1,
A high-voltage switchgear comprising a switch formed such that the distance between the shields is narrower on the front end side of the shield than on the fixed side to the movable conductor. The high voltage switchgear according to claim 1 or 2,
A switch is used in which the shield electrode is mechanically fixed to the movable side conductor via an insulator, and the potential of the shield electrode is lower than that of the movable side conductor. Voltage switchgear.

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