CN114242376A - Transformer neutral point overvoltage protection gas insulation discharge gap - Google Patents
Transformer neutral point overvoltage protection gas insulation discharge gap Download PDFInfo
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- CN114242376A CN114242376A CN202111537767.4A CN202111537767A CN114242376A CN 114242376 A CN114242376 A CN 114242376A CN 202111537767 A CN202111537767 A CN 202111537767A CN 114242376 A CN114242376 A CN 114242376A
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- conducting rod
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/02—Casings
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/28—Coils; Windings; Conductive connections
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
- H01F27/36—Electric or magnetic shields or screens
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T1/00—Details of spark gaps
- H01T1/15—Details of spark gaps for protection against excessive pressure
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
- H02H9/06—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage using spark-gap arresters
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- Power Engineering (AREA)
- Gas-Insulated Switchgears (AREA)
Abstract
The application provides a transformer neutral point overvoltage protection gas insulation discharge gap. This application utilizes to connect metal casing to form seal chamber in order to hold the conducting rod and receive discharge move side bulb and quiet side bulb to provide gas insulation to it. From this, set up the induction coil in the conducting rod periphery can be close the quiet side bulb that links to each other with the transformer neutral point at the moving side bulb and when discharging in insulating gas, respond to the discharge current of being conducted to the conducting rod in by the moving side bulb in step to it is integrated as an organic whole with current transformer with transformer neutral point overvoltage protection discharge gap through single clearance discharge structure, reduce the part size, thereby reduce the insulating distance and reduce the shared space of part and provide higher security performance simultaneously.
Description
Technical Field
The application relates to the field of transformer protection equipment, in particular to a transformer neutral point overvoltage protection gas insulation discharge gap.
Background
After the neutral point of the transformer is led out by the combined electrical appliance for overvoltage protection of the neutral point of the transformer, the neutral point is electrically connected with equipment such as a discharge gap, a current transformer, an isolating switch for grounding, a lightning arrester and the like respectively to be used as neutral point overvoltage comprehensive protection equipment of an ungrounded transformer in an effectively grounded power grid. The electrical principle of which can be seen with reference to fig. 3. The electric elements are electrically isolated by an open air insulation technology. The discharge gap is used as a part of the combined electrical apparatus and mainly plays a role in realizing the electric energy release of the overvoltage of the neutral point of the transformer.
Existing switchgears using air insulation technology often use solid insulation type current transformers, which are connected in series in a loop to measure the current passing through the loop. The existing combined electrical apparatus for overvoltage protection of the neutral point of the transformer is easily influenced by factors such as external environment, humidity, altitude and the like due to the adoption of an open air insulation technology, and the safe distance needs to be kept according to the regulation requirement of a corresponding voltage grade during operation. The discharge gap adopting the air insulation technology occupies a large space, and is not beneficial to the requirement of building an intensive transformer substation; current transformers are often integrally cast by solid insulating media, cannot be integrated with a discharge gap, and installation spaces of the current transformers and the discharge gap are difficult to compress
Disclosure of Invention
The utility model provides a to prior art's not enough, provides a transformer neutral point overvoltage protection gas insulation discharge gap, and it is as transformer neutral point overvoltage integrated protection equipment's partly, wholly adopts SF6 gas insulation technique, can realize the electric energy release of transformer neutral point overvoltage and realize the detection to the bulb internal discharge current value that connects the conducting rod simultaneously with current transformer integration together through inside bulb clearance discharge. The neutral point overvoltage protection device structure of the transformer can be simplified, and the function of measuring the discharge current is integrated. The technical scheme is specifically adopted in the application.
First, in order to achieve the above object, a transformer neutral point overvoltage protection gas insulation discharge gap is provided, which includes: the metal shell is hermetically connected with the common end shell of the neutral point of the transformer and is commonly grounded; the upper part of the conducting rod is in sliding electric connection with the top of the metal shell, and the bottom of the conducting rod is fixedly and electrically connected with a movable ball head; an induction coil disposed at an outer periphery of the conductive rod to detect a current in the conductive rod; the static side ball head is fixedly arranged in a common end shell of the transformer neutral point and is electrically connected with the transformer neutral point; the movable side ball head is positioned above the static side ball head, and the movable side ball head and the static side ball head are both arranged in insulating gas; when the conducting rod slides upwards along the metal shell, the gap distance between the movable-side ball head and the static-side ball head is increased, and the discharge voltage threshold between the ball heads is increased; when the conducting rod slides downwards along the metal shell, the gap distance between the movable side ball head and the static side ball head is reduced, the discharge voltage threshold value between the ball heads is reduced, the insulating gas is broken down when the voltage between the ball heads exceeds the discharge voltage threshold value, and the discharge current is conducted to the conducting rod through the movable side ball head and is discharged to the grounding loop.
Optionally, the transformer neutral point overvoltage protection gas insulation discharge gap as described in any of the above, wherein the ground loop comprises: the upper flange is hermetically connected with the periphery of the conducting rod and arranged above the induction coil; the lower flange is hermetically connected with a common end shell of a neutral point of the transformer and arranged below the induction coil; the metal connecting piece is hermetically arranged between the upper flange and the lower flange and is simultaneously and stably electrically connected with the upper flange and the lower flange; the upper flange, the metal connecting piece and the lower flange are connected on the outer side of the induction coil to form a grounding backflow passage, and the discharge current is guided to be grounded through the grounding backflow passage from the top end of the conducting rod in a single direction.
Optionally, the transformer neutral overvoltage protection gas insulation discharge gap as described in any above, wherein the metal casing forms a ground loop only outside the induction coil.
Optionally, the transformer neutral point overvoltage protection gas insulation discharge gap as described in any of the above, wherein the inner side of the upper flange extends to the lower flange and is formed with a shielding cylinder surrounding the outer circumference of the conducting rod, and the bottom of the shielding cylinder is insulated from the lower flange.
Optionally, the transformer neutral point overvoltage protection gas insulation discharge gap as described in any of the above, wherein the metal connecting member is a jumper metal bar; the bottom of the shielding cylinder is isolated from the lower flange by an insulating connecting piece; the top of the insulating connecting piece is abutted to the bottom end of the shielding cylinder, and the bottom of the insulating connecting piece is abutted to the upper surface of the lower flange.
Optionally, the transformer neutral point overvoltage protection gas insulation discharge gap as described in any of the above, wherein the outside of the induction coil is further provided with a coil housing, and the coil housing is optionally provided inside or outside the crossover metal row.
Optionally, the transformer neutral point overvoltage protection gas insulation discharge gap as described in any of the above, wherein the metal connecting member is a sealed metal cylinder, a top of the sealed metal cylinder is hermetically connected to the upper flange, and a bottom of the sealed metal cylinder is hermetically connected to or integrated with the lower flange; and insulating gas is filled between the bottom of the shielding cylinder and the lower flange.
Optionally, the transformer neutral overvoltage protection gas insulation discharge gap as described in any of the above, wherein the top of the upper flange is sealed by a grounded end cap; the upper end surface or the lower end surface of the grounding end cover is also provided with a contact seat which extends downwards to the inside of the upper flange and surrounds the periphery of the conductive rod; the bottom end of the shielding cylinder is provided with a movable side ball head guide seat; the conductive rod penetrates through the contact seat and the movable-side ball head guide seat, and the movable-side ball head is driven to slide up and down above the static-side ball head under the limitation of the contact seat and the movable-side ball head guide seat.
Optionally, in any of the above transformer neutral point overvoltage protection gas insulation discharge gaps, the movable side ball guide seat and/or the shielding cylinder are made of an insulating material to block electrical contact between the lower flange and the conductive rod; the grounding end cover and the contact seat are made of conductive materials, and the grounding end cover, the contact seat, the upper flange and the conductive rod are electrically connected.
Optionally, the transformer neutral point overvoltage protection gas insulation discharge gap as described above, wherein a gap distance adjusting mechanism is further disposed at a top of the grounding end cap; the static side ball head is arranged on a common end conductor electrically connected with a neutral point of the transformer; the gap distance adjusting mechanism drives the conducting rod to slide downwards or upwards along the central axis direction of the induction coil, so that the discharge voltage threshold between the movable ball head and the static ball head is correspondingly increased or reduced.
Optionally, the transformer neutral point overvoltage protection gas insulation discharge gap as described above, wherein a hand hole is further disposed at a bottom of the common end housing of the transformer neutral point, and an opening direction of the hand hole is opposite to the common end conductor and is located below the dead-side ball head.
Advantageous effects
1, a metal shell is utilized to form a sealed cavity to accommodate a conducting rod and a moving ball head and a static ball head which are in gap discharge, and gas insulation is provided for the conducting rod and the moving ball head and the static ball head. This application is through controlling the conducting rod and slide from top to bottom in the metal casing cavity, adjusts the clearance distance between the bulb to the limit voltage of control clearance discharge realizes neutral point overvoltage protection. From this, set up the induction coil in the conducting rod periphery can be close by the quiet side bulb that transformer neutral point is connected and when discharging in insulating gas at the moving side bulb, respond to the discharge current of being conducted to the conducting rod in by the moving side bulb in step to it is integrated as an organic whole with current transformer with transformer neutral point overvoltage protection discharge gap through single clearance discharge structure, reduce the part size, thereby reduce the insulating distance and reduce the shared space of part and provide higher security performance simultaneously
2, the isolation protection of the neutral point discharge gap of the transformer is realized in a sealed cavity formed by the metal shell through a gas insulation technology. By adopting SF6 as an insulating medium, the insulation distance of the transformer can be effectively reduced, and the distance value of the discharge gap is not limited by the surrounding atmosphere conditions, so that the floor area of the transformer equipment and the requirement on the installation space are reduced, and the equipment floor area and the installation and debugging cost are saved.
3, especially noteworthy is that, this patent can utilize insulating gas medium or utilize insulating connecting piece isolation to block the downward electric path of inboard shielding section of thick bamboo of induction coil through the optimization of butt joint metal casing ground return circuit to guarantee that induction coil only inducts the discharge current of transformer neutral point discharge ground through the conducting rod and can not receive the interference of backward flow electric path signal. Therefore, the installation requirement of an intensive transformer substation is met by the aid of the installation space of the compression equipment while space utilization rate is improved by integrating the discharge bulb and the gas-insulated current transformer into a whole, and the induction coil can effectively induce current signals.
Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application.
Drawings
The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application and not limit the application. In the drawings:
FIG. 1 is a cross-sectional view of a transformer neutral overvoltage protection gas insulated discharge gap of the present application in an off state;
FIG. 2 is a cross-sectional view of another transformer neutral overvoltage protection gas insulated discharge gap discharge state of the present application;
fig. 3 is a schematic diagram of a transformer neutral overvoltage protection combination circuit to which the present application is applied;
in the drawings, 1 denotes a gap distance adjusting mechanism; 2 represents a contact seat; 3 denotes a ground end cap; 4 denotes a conductive rod; 5 denotes an upper flange; 6 denotes an induction coil; 7 denotes a bridging metal row; 8 denotes a coil housing; 9 denotes an insulating member; 10, a movable ball head guide seat; 11 denotes a lower flange; 12 represents a moving-side ball head; 13 denotes a dead-side ball head; 14 denotes a common terminal conductor; 15, a lower tank; 16 denotes a hand hole; 21 denotes a moving-side portion; 22 denotes a current mutual inductance section; 23 denotes a stationary side portion; 31 denotes a transformer; 32 denotes a lightning arrester; a grounding disconnecting switch 33; 34 denotes a switching current transformer; 35 denotes a discharge gap; and 36 denotes a discharge current transformer.
Detailed Description
In order to make the purpose and technical solutions of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings of the embodiments of the present application. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the application without any inventive step, are within the scope of protection of the application.
It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The meaning of "and/or" as used herein is intended to include both the individual components or both.
The meaning of "inside and outside" in the application refers to that the direction from the outside of the bridging metal row to the inside center of the conducting rod is inside, and vice versa, relative to the neutral point overvoltage protection gas insulation discharge gap of the transformer in the application; and not as a specific limitation on the mechanism of the device of the present application.
The term "connected" as used herein may mean either a direct connection between components or an indirect connection between components via other components.
The meaning of "up and down" in the application refers to that when a user faces the overvoltage protection gas insulation discharge gap of the neutral point of the transformer, the direction from the ball head on the dead side to the gap distance adjusting mechanism is up, otherwise, the direction is down, and the device mechanism is not specially limited.
Fig. 1 is a transformer neutral overvoltage protection gas-insulated discharge gap structure according to the present application, mounted outside a transformer tank on the lead-out end of a conductive line led out from the neutral point of a circuit structure in the transformer tank. The leading-out terminal of the neutral point comprises a conductive inner core electrically connected with the neutral point of the transformer and a public terminal shell hermetically connected to the outside of the conductive inner core, insulating gas such as SF6 is filled in the public terminal shell to realize gas insulation, and the public terminal shell is grounded to provide grounding protection. The discharging gap can collect discharging current in the discharging process of the neutral point of the transformer while realizing overvoltage protection on the neutral point of the transformer through the following structure:
the metal shell can be integrally formed or can be realized by connecting a plurality of flanges and other connecting parts, the metal shell is hermetically connected with a common end shell of a neutral point of the transformer and is commonly grounded with the common end shell through a metal material at a connecting part, and a cavity formed by sealing the inside of the metal shell is also communicated with the common end shell, so that insulating gas such as SF6 and the like which is the same as a leading-out end is filled in the cavity, a discharge gap and a leading-out end of the neutral point of the transformer are positioned in a sealed gas insulating environment together, the insulating distance can be effectively shortened, the insulating distance is prevented from being influenced by the external atmospheric environment, and the safety of devices and personnel is ensured;
the common end conductor 14 is arranged in a common end shell of the transformer neutral point and is electrically connected with the transformer neutral point through a conductive inner core, a static ball head 13 is also fixedly arranged on the common end conductor 14, and the static ball head 13 is arranged below the connecting part of the metal shell, is positioned in the common end shell and is electrically connected with the transformer neutral point;
the upper part of the conducting rod 4 is in sliding electrical connection with the top of the metal shell, namely, the conducting rod 4 is in electrical connection with the metal shell through sliding contact, the bottom of the conducting rod 4 is electrically connected with the moving-side ball 12, the conducting rod 4 and the moving-side ball 12 are connected into a whole, the moving-side ball 12 can be driven to move downwards to the bottom position of the metal shell through the downward sliding of the conducting rod 4, and at the moment, the gap discharge is realized between the moving-side ball 12 and the static-side ball 13 through breakdown of insulating gas between the moving-side ball 12 and the static-side ball 13; when the conducting rod 4 slides upwards to the top position of the metal shell, the movable ball head 12 is separated from the range of a discharge gap of the fixed ball head 13, gap discharge is blocked, and no current passes through the conducting rod 4 at the moment;
the induction coil 6 is arranged on the periphery of the conducting rod 4 and located inside the metal shell, the metal shell is sealed in a gas insulation environment, the conducting rod penetrates through the induction coil 6 and conducts discharge current into the conducting rod 4 through the moving-side ball 12 in the process of inducing gap discharge between the moving-side ball and the static-side ball through the induction coil 6, the function of a discharge current transformer 36 which is connected in series in a loop of the transformer 31 and the discharge gap 35 for grounding as shown in fig. 3 is realized, and the measurement of the discharge current passing through the loop is realized.
The movable side ball head and the static side ball head can be realized through a metal ball, and can also be arranged in a hemispherical shape of a conductive structure or only have an arc surface.
Therefore, the discharge structure can integrate the discharge gap ball head structure for overvoltage protection of the neutral point of the transformer and the current transformer into a whole through a gas insulation environment formed by the metal shell, and gas insulation is provided through SF6 gas filled in the metal shell and the common end shell of the neutral point of the transformer. The integration mode not only saves the space occupied by the device, but also reduces the insulation distance required by the device by adopting SF6 as an insulation medium, thereby further reducing the space occupied by the whole transformer system.
Taking the implementation shown in fig. 1 as an example, the above-mentioned transformer neutral overvoltage protection discharge gap can be specifically divided into an upper moving-side portion 21, a lower stationary-side portion 23, and an intermediate current transformer portion 22:
the upper movable-side part includes: clearance distance adjustment mechanism 1, conducting rod 4, contact seat 2 and earthing terminal lid 3. The conductive rod passes through the inside of a current transformer induction coil 6 in the middle downwards from a movable contact seat 2 arranged on the inner side of a grounding end cover 3 at the top of the metal shell; the gap distance adjusting mechanism can be usually fixed on the top of the grounding end cover 3, and drives the top and the corresponding up-and-down linear motion of the conducting rod meshed with the transmission part by selecting the motor and the transmission parts such as a gear, a rack and the like driven by the rotating shaft of the motor; the contact seat surrounds the periphery of the upper part of the conducting rod, is arranged in the middle of the grounding end cover 3 and is in sliding connection with the conducting rod through a ball bearing and other connecting structures, the contact seat is made of metal materials at least at the position where the inner periphery of the contact seat is in direct contact with the conducting rod so as to realize electrical connection through sliding contact, the contact seat 2 can be attached to the periphery of the conducting rod downwards from the upper end surface or the lower end surface of the grounding end cover 3 and extends to the inner periphery of an upper flange 5 in a current mutual inductance part 22, a metal connecting disc structure is formed at the top of the contact seat 2, the bottom surface of the metal connecting disc structure and the top surface of the grounding end cover 3 are fixed and keep the same potential, and therefore, the conducting rod is kept at the grounding potential so as to provide grounding protection for the center point of the transformer;
the intermediate current transformer portion includes: the induction coil 6, the metal shell body formed by the upper flange 5, the lower flange 11 and the bridging metal row 9, and the insulating piece 9, the coil outer cover 8, the moving-side ball head guide seat 10, the shielding cylinder and the like arranged in the induction coil. The induction coil is used for inducing the discharge current of the static ball head passing through the inside of the conducting rod and measuring the current amount of the inner conductor of the conducting rod. The contact seat 2, the grounding end cover 3 and the upper flange 5 of the current transformer are electrically connected through fixed contact. The top of the upper flange 5 is sealed by a grounded end cap 3. The current transformer is arranged on the lower side of the upper flange, the inner part of the upper flange can be extended downwards to form a shielding cylinder surrounding the periphery of the conducting rod 4, and the coil surrounds the outer side of the shielding cylinder and is supported by the shielding cylinder. The contact seat 2 is arranged at the top end of the shielding cylinder to limit the sliding direction of the conducting rod and guide the conducting rod to approach a static ball head at the bottom in a vertical up-down sliding mode or correspondingly leave away; in order to avoid the influence of a grounding backflow passage formed by the shielding cylinder and the lower flange or the metal shell on the inner side of the induction coil on the induction of the induction coil on the discharge current in the conductive rod, an insulating part can be generally arranged between the shielding cylinder and the lower flange, the top of the insulating part 9 is abutted against the bottom end of the shielding cylinder, the bottom of the insulating part 9 is abutted against the upper surface of the lower flange 11, the shielding cylinder cannot form shell backflow through the separation of the insulating part, and therefore the current passing through the conductive rod of the disconnecting switch is ensured to be only in the coil, in addition, an insulating air chamber can be formed between the lower flange and the shielding cylinder through the abutment of the insulating part 8 and the shielding cylinder and the lower flange, so that the insulation protection of a moving contact and a static contact is realized; the coil is surrounded outside the insulating air chamber, the interior of the coil only passes through the induced current, so that the coil can be in contact with air under the protection of the coil outer cover arranged between the upper flange and the lower flange without further increasing the air insulation outside the coil; and a coil outer cover can be further arranged between the upper flange and the lower flange or the coil outer cover is integrally sealed through a metal cylinder on the outer side of the coil, so that the coil is not directly exposed in the atmosphere. In other implementation manners, the coil can be integrally sealed by the grounding shell arranged in a sealing manner, so that the coil is not exposed in the atmosphere and is sealed by the grounding shell outside the coil to realize gas insulation.
In this embodiment, in a manner that an insulating air chamber is formed by sealing the inside of the coil, the outer side of the coil housing 9 is generally required to be matched with the bridging metal row 7 to realize grounding of the flange structure, and the bridging metal row 7 may be optionally disposed on the inner side or the outer side of the coil housing; and under the mode that the gas insulation is realized outside the coil through the integrally sealed grounding shell, a larger insulating air chamber for completely sealing the coil, the ball head and the conducting rod is formed outside the induction coil directly in a mode of welding the upper end and the lower end of the sealed metal cylinder with the flange structure, and the grounding is realized through the integral arrangement of the sealed metal cylinder and the flange structure in the metal shell of the larger insulating air chamber.
The lower flange of the current mutual inductance part is electrically connected with a lower tank body 15 formed by a neutral point common end shell of the lower transformer through fixed contact structures such as welding or sealing bolts; the upper flange and the lower flange can be electrically connected by using a bridging metal row 7 besides realizing the electrical connection through the sealing metal cylinder; the movable-side ball head guide seat 10 can be directly and fixedly arranged at the bottom end of the lower side of the current transformer shielding cylinder, and an insulating guide ring can be arranged in the movable-side ball head guide seat to guide the conducting rod to move up and down and can also be directly made of a metal conducting material; however, considering that burrs may exist on the surface of the structure of the ball head guide seat 10 on the moving side, and the insulating gas is easily broken down when the voltage of the ball head on the static side is higher, a moving contact shielding cover with a smooth metal surface is generally installed on the ball head guide seat 10 on the moving side so as to be matched with the electric field intensity on the two sides of the moving side and the static side of the neutral point leading-out end on the upper part of the switch, and the electric field between the ball head on the moving side and the shielding cylinder is shielded. If the surface of the moving-side ball head guide seat 10 is smooth enough, the moving-contact shielding cover can be omitted, and the performance of the device can not be influenced. The conducting rod shielding cylinder is arranged above the ball head guide seat on the movable side, and the ball head guide seat 10 on the movable side is fixed on the inner periphery of the lower flange 11 so as to be matched with the electric field intensity on the movable side of the upper part of the switch and on the two sides of the static side of the neutral point leading-out end, and avoid the conducting rod from being in electric contact with the shielding cylinder.
In other implementation manners, referring to fig. 2, in order to ensure that the grounding end cap 3 and the upper flange only form a grounding loop at the outer side of the induction coil 6, and a grounding loop cannot be formed between the induction coil and the conductive rod to influence the induction of the discharge current by the induction coil, the grounding loop may be formed by connecting the following conductive components:
an upper flange 5 hermetically connected to the outer periphery of the conductive rod 4 and disposed above the induction coil 6;
the lower flange 11 is hermetically connected with a common end shell of a neutral point of the transformer and is arranged below the induction coil 6;
the metal connecting piece is arranged between the upper flange 5 and the lower flange 11 in a sealing way through a metal cylindrical structure, and is simultaneously and stably electrically connected with the upper flange 5 and the lower flange 11 to provide grounding protection;
the upper flange 5, the metal connecting piece and the lower flange 11 are connected at the outer side of the induction coil 6 to form a grounding backflow path, and the discharge current is guided to be grounded through the grounding backflow path from the top end of the conducting rod 4 in a single direction.
The inner side of the upper flange 5 extends towards the lower flange 11 to form a shielding cylinder surrounding the periphery of the conducting rod 4, the bottom of the shielding cylinder and the lower flange 11 are electrically isolated by using insulating gas sealed in a metal shell and a common end shell of a neutral point as an insulating medium, and the structure of an insulating part 9 in the previous implementation mode is omitted, and a grounding backflow passage is effectively guaranteed between the induction coil 7 and the conducting rod 4.
Therefore, when the neutral point of the transformer needs grounding discharge, the gap distance adjusting mechanism can be set to drive an internal transmission part to drive the conducting rod at the top end of the moving-side ball head to move downwards through the contact seat 2 and the moving-side ball head guide seat 10, and in the sliding process, the moving-side ball head 12 at the bottom end of the conducting rod 4 is guided by the moving-side ball head guide seat 10 to enable the moving-side ball head 12 to be opposite to the upper part of the common end conductor 14, when the neutral point voltage exceeds a discharging voltage interval corresponding to the gap of the moving-side ball head and the static-side ball head, discharging occurs between the moving-side ball head and the static-side ball head, and the electrical connection among the static-side ball head, the moving-side ball head, the conducting rod, the grounding end cover and the upper flange of the current transformer is realized, and discharging current can enter the conducting rod through a discharging mode, and then passes through the grounding end cover 3 and the upper flange of the top of the conducting rod through a bridging metal row or a sealing metal cylinder and the lower flange of the current transformer, The lower tank body is connected with the grounding net, so that overvoltage discharge of the transformer neutral point gas insulated switchgear is realized, and the induction coil only has discharge current passing through the conducting rod, so that the induction coil can detect the discharge current value passing through the conducting rod through induction current triggered by the discharge current in the discharge process.
And in cooperation with the movable side part and the current transformer part, the static side part of the lower part of the discharge gap, which is connected with a neutral point leading-out end of the transformer, can be electrically connected with the movable side ball head through a static side ball head 13 and a common end conductor 14. The static side ball head is arranged at the top end of a common end conductor led out from a transformer neutral point oil gas sleeve and is positioned in a lower tank body formed by a transformer neutral point common end shell. The tank body can be further provided with a hand hole 16 at the lower part of the tank body close to the static side, namely the bottom of the public end shell of the neutral point of the transformer, and the opening direction of the hand hole can be opposite to the public end conductor 14 and is positioned below the conducting rod 4 and the static side ball head so as to be convenient for observing and overhauling the ball head structure.
In some implementation modes, in order to prevent the movable-side ball head, the conductive rod seat, the gap side end cover and the upper flange from forming a discharge current path downwards on the inner side of the coil through the shielding cylinder, so that the conduction of a grounding path formed outside the current transformer coil by the upper flange, the metal connecting piece and the lower flange to the discharge current is influenced, and further the detection of the induction coil to the discharge current is influenced, any one or both of the movable-side ball head guide seat 10 and the shielding cylinder can be selected to be made of an insulating material, so that the electric contact between the lower flange 11 and the conductive rod 4 is blocked, and the grounding path connected to a grounding net by a gas insulation tank body is formed outside the induction coil. And in order to ensure the discharge current path outside the induction coil, the grounding end cover 3 and the contact seat 2 in the structure can be correspondingly selected to be made of conductive materials, so that the top end of the conductive rod is connected to the grounding current path through the electric connection among the grounding end cover 3, the contact seat 2, the upper flange 5 and the conductive rod 4 to realize the drainage of the discharge current.
Thus, when overvoltage protection is performed according to a voltage value specified by the transformer line, the gap distance adjusting mechanism 1 drives the conducting rod 4 to slide to a proper position along the central axis direction of the induction coil 6, so that the movable and stationary bulbs can keep a proper gap distance, wherein the gap distance corresponds to one section of a discharge voltage value. When the neutral point voltage exceeds the voltage value range, gap discharge is carried out, so that a grounding path is formed between the two ball heads, current is guided through the conducting rod to be grounded in a single direction through the upper flange and the grounding end cover, and single-direction discharge current capable of being detected by the induction coil is formed in the conducting rod; when the voltage of the neutral point does not exceed the voltage value interval corresponding to the gap distance, the gap does not discharge, the electric contact between the ball heads is disconnected, and the independent operation of the neutral point of the transformer is ensured.
In summary, the switch structure of the present application has the following advantages:
1, the movable side, the static side and the current transformer are integrated into an integrated structure by the discharge gap provided by the application, and are placed in SF6 insulating gas, so that the functions of grounding and current measurement are realized, the occupied space is smaller, the insulating property is not influenced by external weather, and the safety and the stability are higher;
2, the movable side bulb, the conducting rod seat, the gap side end cover and the upper flange of the gas insulation discharge gap required by the patent form a discharge current path inside the current transformer coil, then an upper flange, a metal connecting piece and a lower flange form a grounding path outside the current transformer coil, and finally a gas insulation tank body is connected into a grounding network to ensure that the metal shell of the application can be stably grounded so as to improve the safety of the whole discharge gap structure. By adjusting the distance of the air gap between the ball heads on the moving side and the static side, the overvoltage protection of the neutral point gas insulation combined electrical appliance of the transformer under a specified voltage value can be realized. After the conducting rod moves downwards to be close to the ball head at the static side, the discharge grounding of the transformer neutral point gas insulation combined electrical apparatus can be realized. The shell and the bridging metal bar are connected into the grounding grid, so that the device can be protected from being electrified outside, and the safety performance is higher.
3, in the discharge gap provided by the application, the movable-side ball head guide seat is arranged at the bottom end of a shielding cylinder in the current transformer and can guide a conductive rod with longer length to linearly move and extend into the lower tank body to be close to the static-side ball head to form a discharge grounding path of a transformer neutral point; the conducting rod passes through the inside of the current transformer and is connected with a grounding loop through a grounding end cover, so that the current quantity passing through the conducting rod can be conveniently measured;
4, the quiet side of discharge gap that this application provided is installed on the public end conductor that transformer neutral point oil gas sleeve pipe was drawn forth, and the jar body lower part of mounted position still sets up the access hand hole. The application provides a discharge clearance for ground connection will move the side and separately arrange with quiet side, and the upper portion switch structure is conveniently observed, maintained in the hand hole of maintenance of usable quiet side lower part.
The above are merely embodiments of the present application, and the description is specific and detailed, but not to be construed as limiting the scope of the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the protection scope of the present application.
Claims (11)
1. A transformer neutral overvoltage protection gas insulated discharge gap, comprising:
the metal shell is hermetically connected with the common end shell of the neutral point of the transformer and is commonly grounded;
the upper part of the conducting rod (4) is in sliding electric connection with the top of the metal shell, and the bottom of the conducting rod is fixedly and electrically connected with a movable ball head (12);
an induction coil (6) provided at the outer periphery of the conductive rod (4) to detect a current in the conductive rod (4);
the static side ball head (13) is fixedly arranged in the common end shell of the transformer neutral point and is electrically connected with the transformer neutral point; the movable-side ball head (12) is positioned above the static-side ball head (13), and the movable-side ball head (12) and the static-side ball head (13) are both arranged in insulating gas;
when the conducting rod (4) slides upwards along the metal shell, the gap distance between the movable-side ball head (12) and the static-side ball head (13) is increased, and the discharge voltage threshold value between the ball heads is increased;
when the conducting rod slides downwards along the metal shell, the gap distance between the movable-side ball head (12) and the static-side ball head (13) is reduced, and the discharge voltage threshold between the ball heads is reduced;
when the voltage between the ball heads exceeds the discharge voltage threshold value, the insulating gas is broken down, and the discharge current is conducted to the conducting rod (4) through the moving-side ball head (12) and is discharged to the grounding loop.
2. The transformer neutral overvoltage protection gas insulated discharge gap of claim 1 wherein said ground return path includes:
an upper flange (5) which is hermetically connected with the periphery of the conducting rod (4) and is arranged above the induction coil (6);
the lower flange (11) is hermetically connected with a common end shell of a neutral point of the transformer and is arranged below the induction coil (6);
the metal connecting piece is hermetically arranged between the upper flange (6) and the lower flange (11) and is simultaneously and stably and electrically connected with the upper flange (6) and the lower flange (11);
the upper flange (5), the metal connecting piece and the lower flange (11) are connected on the outer side of the induction coil (6) to form a grounding backflow path, and discharge current is guided to be grounded through the grounding backflow path in a single direction from the top end of the conducting rod (4).
3. A transformer neutral overvoltage protection gas insulated discharge gap according to claim 2 characterized in that said metal housing forms a ground return only outside the induction coil (6).
4. A transformer neutral overvoltage protection gas-insulated discharge gap according to claim 2, characterized in that the inner side of said upper flange (5) extends towards the lower flange (11) and is formed with a shielding cylinder surrounding the outer circumference of the conducting rod (4), the bottom of said shielding cylinder being insulated from the lower flange (11).
5. The transformer neutral overvoltage protection gas insulated discharge gap according to claim 4 wherein said metal connections are bridging metal rows (7);
the bottom of the shielding cylinder is isolated from the lower flange (11) by an insulating connecting piece (9);
the top of the insulating connecting piece (9) is abutted to the bottom end of the shielding cylinder, and the bottom of the insulating connecting piece (9) is abutted to the upper surface of the lower flange (11).
6. The transformer neutral overvoltage protection gas insulated discharge gap according to claim 5, characterized in that the outside of the induction coil (6) is further provided with a coil housing (9), the coil housing (9) being optionally provided inside or outside the jumper metal row (7).
7. The transformer neutral overvoltage protection gas insulated discharge gap according to claim 4, wherein said metal connector is a sealed metal cylinder, the top of said sealed metal cylinder is sealingly connected to an upper flange (5), and the bottom of said sealed metal cylinder is sealingly connected to or integrally provided with a lower flange (11);
and insulating gas is filled between the bottom of the shielding cylinder and the lower flange (11).
8. The transformer neutral overvoltage protection gas insulated discharge gap according to claim 4, characterized in that the top of said upper flange (5) is sealed by a grounded end cap (3);
the end face of the grounding end cover (3) is also provided with a contact seat (2) which extends downwards to the inside of the upper flange (5) and surrounds the periphery of the conductive rod (4);
the bottom end of the shielding cylinder is provided with a movable side ball head guide seat (10);
the conductive rod (4) penetrates through the contact seat (2) and the movable-side ball head guide seat (10), and the movable-side ball head (12) is driven to slide up and down above the static-side ball head (13) under the limitation of the contact seat (2) and the movable-side ball head guide seat (10).
9. The transformer neutral point overvoltage protection gas insulation discharge gap according to claim 7, wherein the movable side ball head guide seat (10) and/or the shielding cylinder are made of insulating materials, and the lower blocking flange (11) is electrically contacted with the conducting rod (4);
the grounding end cover (3) and the contact seat (2) are made of conductive materials, and the grounding end cover (3), the contact seat (2), the upper flange (5) and the conductive rod (4) are electrically connected.
10. The transformer neutral overvoltage protection gas insulated discharge gap according to claim 1, characterized in that the top of said earth end cap (3) is further provided with a gap distance adjusting mechanism (1);
the static side ball head (13) is arranged on a common end conductor (14) electrically connected with a neutral point of the transformer;
the gap distance adjusting mechanism (1) drives the conducting rod (4) to slide downwards or upwards along the central axis direction of the induction coil (6).
11. A transformer neutral overvoltage protection gas insulated discharge gap according to claim 10 wherein said transformer neutral common terminal housing is further provided with a hand hole (16) in a bottom portion thereof, said hand hole being directed opposite said common terminal conductor (14) and below said dead side bulb (13).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111537767.4A CN114242376A (en) | 2021-12-15 | 2021-12-15 | Transformer neutral point overvoltage protection gas insulation discharge gap |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111537767.4A CN114242376A (en) | 2021-12-15 | 2021-12-15 | Transformer neutral point overvoltage protection gas insulation discharge gap |
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| CN114242376A true CN114242376A (en) | 2022-03-25 |
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| CN202111537767.4A Pending CN114242376A (en) | 2021-12-15 | 2021-12-15 | Transformer neutral point overvoltage protection gas insulation discharge gap |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201207564Y (en) * | 2008-04-23 | 2009-03-11 | 西安安捷迅电气有限公司 | Protection device for transformer earthing |
| CN101621185A (en) * | 2009-06-15 | 2010-01-06 | 上海安越电气工程技术有限公司 | Transformer neutrality point combination electric device |
| CN201774230U (en) * | 2010-08-13 | 2011-03-23 | 上海上友电气科技有限公司 | Transformer neutral point over-voltage protection device |
| CN204188677U (en) * | 2014-12-03 | 2015-03-04 | 哈尔滨理工大学 | A kind of device preventing high precision electrometer to be burned in high-voltage test |
| CN204407764U (en) * | 2014-12-29 | 2015-06-17 | 浙江日新电气有限公司 | 110kV transformer neutral point complete set of equipments |
| CN105140903A (en) * | 2015-09-21 | 2015-12-09 | 中电新源智能电网科技有限公司 | Transformer neutral point gas insulated substation |
| WO2021052053A1 (en) * | 2019-09-18 | 2021-03-25 | 国网浙江省电力有限公司经济技术研究院 | Gas-insulated metal enclosed neutral point complete-set device |
-
2021
- 2021-12-15 CN CN202111537767.4A patent/CN114242376A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201207564Y (en) * | 2008-04-23 | 2009-03-11 | 西安安捷迅电气有限公司 | Protection device for transformer earthing |
| CN101621185A (en) * | 2009-06-15 | 2010-01-06 | 上海安越电气工程技术有限公司 | Transformer neutrality point combination electric device |
| CN201774230U (en) * | 2010-08-13 | 2011-03-23 | 上海上友电气科技有限公司 | Transformer neutral point over-voltage protection device |
| CN204188677U (en) * | 2014-12-03 | 2015-03-04 | 哈尔滨理工大学 | A kind of device preventing high precision electrometer to be burned in high-voltage test |
| CN204407764U (en) * | 2014-12-29 | 2015-06-17 | 浙江日新电气有限公司 | 110kV transformer neutral point complete set of equipments |
| CN105140903A (en) * | 2015-09-21 | 2015-12-09 | 中电新源智能电网科技有限公司 | Transformer neutral point gas insulated substation |
| WO2021052053A1 (en) * | 2019-09-18 | 2021-03-25 | 国网浙江省电力有限公司经济技术研究院 | Gas-insulated metal enclosed neutral point complete-set device |
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