CN211404203U - Current Transformers for Substations - Google Patents

Abstract

The utility model discloses a current transformer used in a substation, which extends the position of an oil discharge port, expands the function of the oil discharge port, and is very practical; the utility model also improves the top protective cover and the interior thereof, so that the It is clearer to observe the height of the expander, and the operation process of the expander can be easily limited by the internal integrated limit component. In the utility model, the oil drain port is provided with a tee, and the tee includes an oil drain port interface for installation with the oil drain port, a reserved interface for connecting with a plug or an oil pressure monitoring sensor, and a connection for connecting down sampling The bottom of the down sampling pipe is equipped with a down drain valve; a window is opened on the top protective cover, a rubber frame is installed on the inner wall of the window, and an indicator line observation window is installed in the rubber frame, and the outer edge of the rubber frame is coated with A circle of waterproof glue is covered; the expander is coated with a circle of position indication lines; the top protective cover is provided with an expander oil injection and oil extraction limit assembly.

Description

Current Transformers for Substations

technical field

The utility model relates to an improvement of a current transformer in a substation, in particular to an outdoor oil-immersed current transformer used in the substation.

Background technique

The use of oil-immersed current transformers in substations in Xinjiang is very common. This current transformer is used outdoors. In recent years, we have paid great attention to the safe operation of this equipment, and have invested R&D efforts to monitor the status of oil-immersed current transformers. The oil pressure and oil temperature sensor is used to monitor the oil to achieve our monitoring purpose;

Through long-term operation and the implementation of a series of safe and stable operation technologies, we have gained a more detailed experience in the use of oil-immersed current transformers, and also found some structural defects that are not conducive to daily reliable use. This application is dedicated to Addresses the following identified defects:

(1) When we installed sensors at the bottom oil drain port and the top expander position of the oil-immersed current transformer, we found that the oil drain port was too high, and it was very inconvenient to add components or take oil samples later. There is no expansion port for the oil port. Once it needs to be installed, the oil drain port can only be modified on site, which takes a long time and causes the power outage time to be too long.

(2) We inject oil into the expander at the top of the oil-immersed current transformer or observe the liquid level daily (the change of the expansion height of the expander reflects the change of the oil position inside the expander), and the observation window of the expander is easily damaged. , the height position is not easy to be clearly and accurately detected. In addition, when the expander is filled with oil or installed components, the expander must be in a fully extended state, otherwise the oil filling will be non-standard or the oil will be sprayed out when the oil filling hole is opened; this special It is very troublesome to make tools on site or reserve them in advance every time; on-site production is mainly a tool for stretching the expander and limiting the position. On-site production is relatively easy for experienced personnel, and it is not easy to cause potential safety hazards, but for lack of experience very uncontrollable for the personnel.

(3) When installing oil-immersed current transformers in substations, it is currently necessary to dig deep pits on site, and bury the supporting pipe columns into the deep pits like street lamp poles and fix them with concrete. The procedure of the on-site operation process is complicated and time-consuming. It is labor-intensive and often affected by the weather. If there are hidden dangers in the support structure of the supporting pipe string, it will lead to a great safety hazard in the operation of the oil-immersed current transformer.

Utility model content

The technical problem to be solved by the utility model is that aiming at the above-mentioned deficiencies in the prior art, a current transformer for a substation is disclosed, which extends the position of the oil drain port and expands the function of the oil drain port, which is very practical; The utility model also improves the top protective cover and its interior, so that the height of the expander can be observed more clearly, and the operation process of the expander can be conveniently limited by the internal integrated limiting component, which is convenient for reliable and fast operation.

The technical solution adopted by the utility model to solve the technical problem is: a current transformer used in a substation, a transformer body including an oil-immersed current transformer, an expander on the top of the transformer body, and a top protection on the outer cover of the expander cover, the bottom of the transformer body is supported and fixed by the support pipe column, the outer surface of the bottom of the transformer body close to the support pipe column is provided with a junction box, and the junction box has lead wires, and the position of the transformer body near the bottom is also provided with a junction box for sampling the oil drain port;

It is characterized in that: the oil drain port is installed with a tee, and the tee includes an oil drain port interface for installation with the oil drain port, a reserved interface for connecting with a plug or an oil pressure monitoring sensor, and a connection for connecting the down-conductor. The interface of the sampling pipe; the bottom of the down sampling pipe is equipped with a down drain valve;

The top protective cover is provided with a window, a ring of rubber frame is installed on the inner wall of the window, an indicator line observation window is installed in the rubber frame, and the outer edge of the rubber frame is coated with a ring of waterproof glue;

A circle of position indicator lines is coated on the expander, and the highest position and the lowest position of the expander are both located in the visible area of the indicator line window;

The top protective cover is provided with an expander oil injection and oil extraction limit assembly; the oil injection and oil extraction limit assembly includes a limit snap ring for clamping the corrugated valley position of the corrugated expander, and the limit snap ring is divided into two parts. The left half ring and the right half ring are symmetrical, and flanges with threaded holes are arranged at the butting positions of the left half ring and the right half ring, and the left half ring and the right half ring are fastened after the locking screw passes through the flange; The distal ends of the left half ring and the right half ring are provided with bosses with through holes, the top of the screw rod passes through the through holes of the boss, the bottom of the screw rod passes through the upper folded edge of the bracket, and the lower folded edge of the bracket is fixed on the bracket. on the pad;

The upper and lower parts of the boss are respectively provided with upper bolt adjustment pairs engaged with the screw rods, and the upper and lower sides of the upper folded edge are respectively provided with lower bolt adjustment pairs engaged with the screw rods.

As a preferred embodiment of the present utility model: the position indicator line is red and is sprayed on the wave crest position of the corrugated expander.

As a preferred embodiment of the present invention, the left half ring and the right half ring are formed into a circle after being butted, and the diameter of the circle is smaller than the diameter of the trough position of the corrugated expander.

As a preferred embodiment of the present invention: the oil drain port is a one-way valve, and the oil drain port of the three-way is installed and matched with the one-way valve, and the oil in the oil drain port flows into the remaining two of the three-way. interface.

As a preferred embodiment of the present utility model: the junction box and the lead wires are respectively covered with a junction box cover body and a pipeline cover body designed in one piece, and the junction box cover body is a cylindrical structure with an open bottom surface and a closed top surface. The side of the box cover is connected with a pipeline cover, and the pipeline cover is a tubular structure with openings at both ends; along the center position of the pipeline cover and the junction box cover, there is an open seam for covering the lead wire and the junction box after breaking apart. The part of the opening seam located in the pipeline cover is the pipeline opening seam, and the part of the opening seam located in the junction box cover is the opening seam of the cover body.

As a preferred embodiment of the present invention, the junction box cover and the pipeline cover are covered with a junction box and lead wires and then a sealant is applied at the position of the opening seam.

As a preferred embodiment of the present invention, the top surface of the cover of the junction box is a convex arc-shaped cover.

As a preferred embodiment of the present utility model: the prefabricated pit on the ground at the bottom of the support pipe string, the diameter of the prefabricated pit is larger than the diameter of the support pipe string; the top edge of the prefabricated pit is prefabricated and fixed with a prefabricated plate, and the prefabricated plate is prefabricated and fixed There are prefabricated anchor bolts; it also includes a butt clamp tube for clamping and fixing the support pipe column, the butt clamp pipe is arranged symmetrically on the left and right, and the inner diameter of the symmetrical clamp pipe is smaller than the diameter of the support pipe column; the bottom of the butt clamp pipe is used for The round table is fixed with the prefabricated plate, and the round table is provided with strip holes corresponding to the prefabricated anchor bolts; the positions where the left half and the right half of the symmetrical clamp tube are butted are radially extended with a fastening extension plate, and the fastening bolts Connect the left and right halves of the docking tube after passing through the fastening extension plate.

As a preferred embodiment of the present invention, obliquely connected reinforcing ribs are distributed between the circular platform of the butt-jointed clamp tube and the side surface of the butt-jointed clamp pipe; the number of the anchor bolts is at least four evenly distributed.

As a preferred embodiment of the present utility model: concrete is filled between the support pipe string and the prefabricated pit; the height of the prefabricated pit is greater than 1/4 of the height of the support pipe string; the height of the butt-jointed pipe is greater than that of the support pipe 1/5 of the column height.

Compared with the prior art, the utility model has the following advantages:

The utility model discloses a current transformer used in a substation, wherein a tee is installed at the oil discharge port, and the tee comprises an oil discharge port interface for installation with the oil discharge port, and a plug for monitoring the plug or oil pressure. The reserved interface for sensor connection and the interface for connecting the down sampling pipe; the bottom of the down sampling pipe is equipped with a down oil drain valve; the three-way reduces the height of the oil drain valve through the down sampling pipe, so that the operation is convenient , reduce the safety hazards of climbing; through the reserved interface of the tee, monitoring components such as oil pressure sensors can be installed, which expands the function of the original oil discharge port, and can be installed in advance according to the power outage plan. The monitoring components are easy to assemble, greatly reducing manual installation time.

The top protective cover of the utility model is provided with a window, a rubber frame is installed on the inner wall of the window, an indicator line observation window is installed in the rubber frame, and the outer edge of the rubber frame is coated with a ring of waterproof glue; the observation window is provided with waterproof and rubber structures Reliability can be guaranteed, so that the area of the observation window can be increased to improve the visual effect; in addition, the utility model coats a circle of position indicating lines on the expander, and the highest position and the lowest position of the expander are located at The visible area of the indicator line window; the position of the indicator line in the observation window can be very intuitively detected.

The top protective cover of the present utility model is provided with an expander oil injection and oil removal limit assembly; the oil injection and oil removal limit assembly includes a limit snap ring for clamping the trough position of the corrugation of the corrugated expander. The limit snap ring is divided into a symmetrical left half ring and a right half ring. A flange with a threaded hole is set at the butting position of the left half ring and the right half ring. After the locking screw passes through the flange, the left half ring and the right half ring are connected. The half ring is fastened; the distal ends of the left half ring and the right half ring are provided with bosses with through holes, the top of the screw rod passes through the through holes of the boss, the bottom of the screw rod passes through the upper fold of the bracket, and the The lower folded edge is fixed on the spacer block; the upper and lower parts of the boss are respectively provided with upper bolt adjustment pairs engaged with the screw rod, and the upper and lower sides of the upper folded edge are respectively provided with lower bolt adjustment pairs engaged with the screw rod. The utility model integrates the limit component inside the top protective cover, so it can be used as long as the protective cover is opened, and the limit component is also used for oil injection or sensor installation of the expander, and the first step of oil injection or sensor installation is also The protective cover must be opened, so it is very convenient; since the core of the limit component is the limit snap ring, it occupies a small space, and the tightening state does not affect the change of the expander itself; the bracket is also a relatively light structure, and the two sides pass through The folded edge realizes the fixing function; the upper and lower bolt adjustment pairs are very easy to adjust, the whole structure is simple, and after integration, there is no need to make troubles and troubles for the use of on-site limit tools.

Description of drawings

1 is a schematic structural diagram of an oil-immersed current transformer commonly used in substations in the prior art;

Fig. 2 is the structural schematic diagram of the oil drain port installation assembly of the present invention;

Fig. 3 is the structural schematic diagram of the top protective cover of the present invention;

4 is a schematic diagram of the internal structure of the top protective cover of the present invention;

5 is a schematic structural diagram of a junction box protective cover of the present invention;

FIG. 6 is a schematic diagram of the bottom installation structure of the support pipe string of the present invention.

Description of reference numbers:

1- Top protective cover, 2- Expander, 3- Transformer body, 4- Junction box, 5- Lead wire, 6- Support pipe string, 7- Oil drain;

41-junction box cover, 42-arc cover, 43-cover opening slit, 44-pipeline opening slit, 45-pipeline cover;

71-Tee, 72-Reserved interface, 73-Oil drain port, 74-Drain sampling pipe, 75-Drain drain valve;

101-rubber frame, 102-indicating line observation window, 103-waterproof glue, 104-position indicating line, 105-limiting snap ring, 106-locking screw, 107-height adjusting screw, 108-upper bolt adjustment pair, 109 - lower bolt adjustment pair, 110- bracket, 111- spacer;

601-ground, 602-prefabricated plate, 603-prefabricated anchor bolt, 604-prefabricated pit, 605-strip hole, 606-reinforcing rib, 607-butt clamp, 608-fastening extension plate, 609-fastening bolt .

Detailed ways

The present invention will be described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments do not limit the present invention, and those of ordinary skill in the art can perform functions, methods, or structures according to these embodiments. Equivalent transformation or replacement of the above all belong to the protection scope of the present invention.

As shown in Figures 1 to 6, it shows a specific embodiment of the present invention; as shown in the figure, the current transformer for substation disclosed by the present invention includes a transformer body 3 of an oil-immersed current transformer , the top of the transformer body 3 has an expander 2, the outer cover of the expander is provided with a top protective cover 1, the bottom of the transformer body is supported and fixed by the support pipe string 6, and the outer surface of the bottom of the transformer body near the position of the support pipe string is provided with wiring Box 4, there are lead wires 5 on the junction box, and the position of the transformer body close to the bottom is also provided with an oil drain 7 for sampling; the description in this part is the basic structure of the current transformer used in the substation. In order to save space, The specification only records and describes the structural components related to the improved position, and the rest of the detailed structures belong to the prior art; and the basic structure described in this specification is an accurate, reliable and unmistakable prior art, and those skilled in the art can use the basic description to correspond to the existing technology. Some oil-immersed current transformers; the structure position of the prior art, especially the improved position and structure, will not be repeated in this specification.

It is characterized in that: the oil drain port 7 is provided with a tee 71, and the tee includes an oil drain port 73 for installing with the oil drain port, a reserved interface 72 for connecting with a plug or an oil pressure monitoring sensor, and a It is connected to the interface of the down sampling pipe 74; the bottom of the down sampling pipe 74 is installed with a down oil drain valve 75;

The top protective cover 1 is provided with a window, a ring of rubber frame 101 is installed on the inner wall of the window, an indicator line observation window 102 is installed in the rubber frame, and the outer edge of the rubber frame is coated with a ring of waterproof glue 103;

A circle of position indicating line 104 is coated on the expander, and the highest position and the lowest position of the expander are both located in the visible area of the indicating line window;

The top protective cover 1 is equipped with an expander oil injection and oil limit assembly; the oil injection and oil limit assembly includes a limit snap ring 105 for clamping the corrugated trough position of the corrugated expander 2. The limit The snap ring is divided into a symmetrical left half ring and a right half ring, and flanges with threaded holes are provided at the butting positions of the left half ring and the right half ring. After the locking screw 106 passes through the flange, the left half ring and the right half ring are connected The ring is fastened; the distal ends of the left half ring and the right half ring are provided with a boss with a through hole, the top of the screw 107 passes through the through hole of the boss, and the bottom of the screw passes through the upper edge of the bracket 110, the bracket The lower folded edge of 110 is fixed on the cushion block 111;

The upper and lower parts of the boss are respectively provided with upper bolt adjustment pairs 108 engaged with the screw rods, and the upper and lower sides of the upper hem are respectively provided with lower bolt adjustment pairs 109 engaged with the screw rods. The bolt adjustment pair consists of two bolts, and the height adjustment and the reliable fixation after adjustment are realized through the up and down adjustment.

Preferably, as shown in Figure 4: the position indicator line is red and is sprayed on the wave crest position of the corrugated expander. The wave crest position refers to the protruding part for the corrugated structure, and the coating position indication line of the protruding part can be closer to the observation window, which is easier for the tanker; for the corrugated structure, it includes the protruding part and the concave part of the interval, and the protruding part is The wave crest and the concave part are the wave trough.

Preferably, as shown in FIG. 4 , the left half ring and the right half ring are formed into a circle after being butted, and the diameter of the circle is smaller than the diameter of the trough position of the corrugated expander. The diameter of the left half ring and the right half ring is smaller than the trough position of the expander, so that the limit snap ring can be fully tightened and the trough position can be securely clamped.

Preferably, as shown in Figures 1 and 2, the oil drain port 7 is a one-way valve, and the oil drain port of the three-way is installed and matched with the one-way valve, and the oil in the oil drain port flows into the other two of the three-way. an interface. The one-way valve prevents oil leakage after disassembly.

Preferably, as shown in FIG. 5 : the junction box 4 and the lead wire 5 are respectively covered with a junction box cover 41 and a pipeline cover 45 designed in one piece, and the junction box cover is a cylindrical structure with an open bottom surface and a closed top surface. The side of the junction box cover is connected with a pipeline cover, and the pipeline cover is a tubular structure with openings at both ends; Opening seam; the part of the opening seam located in the pipeline cover is the pipeline opening seam 44, and the part of the opening seam located in the junction box cover is the opening seam 43 of the cover body. In this embodiment, the junction box cover and the pipeline cover are installed in view of the defect that the position of the junction box is exposed for a long time and easy to be fouled; the installation process is also very simple. Plastic parts will do.

Preferably, as shown in FIG. 5 , the junction box cover 41 and the pipeline cover 45 cover the junction box and the lead wires and then apply sealant at the position of the opening seam. After the cover is installed, applying sealant to the opening seams and other gaps can make the junction box work more reliably in a sealed environment, ensure isolation from the outside world, and improve stability. The removal of the sealant is relatively simple and does not affect the removal and maintenance.

Preferably, as shown in FIG. 5 , the top surface of the cover body of the junction box is a convex arc-shaped cover body 42 . The curved cover allows rainwater to slide off smoothly.

Preferably, as shown in FIG. 6: the prefabricated pit 604 on the ground at the bottom of the support pipe string, the diameter of the prefabricated pit 604 is larger than the diameter of the support pipe string 6; the top edge of the prefabricated pit is prefabricated and fixed with a prefabricated plate 602, and the prefabricated plate Prefabricated and fixed with prefabricated anchor bolts 603; also includes a butt clamp 607 for clamping and fixing the support pipe string, the butt clamp pipe 607 is symmetrically arranged on the left and right, and the inner diameter of the symmetrical clamp pipe is smaller than the diameter of the support pipe string; the butt clamp The bottom of the tube is a round table for fixing with the prefabricated plate, and the round table is provided with strip holes 605 corresponding to the prefabricated anchor bolts 603 (the strip holes are also called waist holes); the left half and right half of the symmetrical clamp tube A fastening extension plate is radially extended at the positions of the butt joints, and the fastening bolts pass through the fastening extension plate to connect the left half and the right half of the butt clamp tube. In this embodiment, the prefabricated pit can be made in advance. On the spot, only the butt-jointed clamp pipes are butted and then tightened to clamp the support pipe column. The circular platform of the butt-jointed clamped pipe is fixed by the anchor bolts. Adjust the position for the best clamping effect. In this way, this embodiment realizes the fixation of the support pipe string below the ground and the fixation below the ground. During the on-site installation, since the prefabricated pit is prepared in advance, after the support pipe string is inserted, the fixed butt is stuck and the ground is fixed. It is an efficient assembly process, no need to wait for solidification, no need to consider weather factors.

Preferably, as shown in FIG. 6 , obliquely connected reinforcing ribs 606 are distributed between the circular platform of the butt-jointed clamp tube and the side surface of the butt-jointed clamp pipe; the number of the anchor bolts is at least four evenly distributed. The reinforcing rib ensures that the position of the butt-jointed pipe is reliable and stable.

Preferably, as shown in Figures 1 and 6: concrete is filled between the support pipe string and the prefabricated pit; the height of the prefabricated pit is greater than 1/4 of the height of the support pipe string; the height of the butt-jointed pipe is greater than that of the support pipe 1/5 of the column height. This embodiment discloses a better dimensional relationship, which can ensure the reliable and stable fixation of the support pipe column; the filling of the concrete does not need to wait for solidification, and it can be naturally solidified after the construction is completed.

A series of detailed descriptions listed above are only specific descriptions for the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalents made without departing from the technical spirit of the present invention Embodiments or changes should all be included within the protection scope of the present invention.

In addition, it should be understood that although this specification is described in terms of embodiments, not each embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (10)

1. The current transformer for the transformer substation comprises a transformer body of the oil-immersed current transformer, wherein an expander is arranged at the top of the transformer body, a top protective cover is covered outside the expander, the bottom of the transformer body is supported and fixed through a supporting pipe column, a junction box is arranged on the outer surface of the bottom of the transformer body close to the supporting pipe column, a lead-out wire is arranged on the junction box, and an oil discharge port for sampling is also arranged at the position of the transformer body close to the bottom;

the method is characterized in that: the tee joint comprises an oil discharge port interface used for being installed with the oil discharge port, a reserved interface used for being connected with a plug or an oil pressure monitoring sensor and an interface used for being connected with a down-leading sampling pipe; the bottom of the down-leading sampling pipe is provided with a down-leading oil-discharging valve;

the top protective cover is provided with a window, the inner wall of the window is provided with a circle of rubber frame, an indicating line observation window is arranged in the rubber frame, and the outer edge of the rubber frame is coated with a circle of waterproof rubber;

a circle of position indicating lines are coated on the expander, and the highest position and the lowest position of the expander are both positioned in a visible area of the indicating line window;

an expander oil injection and extraction limiting assembly is arranged in the top protective cover; the oil injection and oil extraction limiting assembly comprises a limiting clamping ring for clamping the corrugation trough position of the corrugation expander, the limiting clamping ring is divided into a left half ring and a right half ring which are symmetrical, flanges with threaded holes are arranged at the butt joint positions of the left half ring and the right half ring, and a locking screw penetrates through the flanges to fasten the left half ring and the right half ring; the far ends of the left half ring and the right half ring are provided with bosses with through holes, the top of the screw rod penetrates through the through holes of the bosses, the bottom of the screw rod penetrates through the upper folded edge of the support, and the lower folded edge of the support is fixed on the cushion block;

the upper and lower parts of the boss are respectively provided with an upper bolt adjusting pair meshed with the screw rod, and the upper and lower parts of the upper folded edge are respectively provided with a lower bolt adjusting pair meshed with the screw rod.

2. The current transformer for a substation of claim 1, wherein: the position indication lines are red and sprayed at the positions of the peaks of the bellow expander.

3. The current transformer for a substation of claim 1, wherein: the left half ring and the right half ring are circular after being butted, and the diameter of the circle is smaller than that of the wave trough position of the corrugated expander.

4. The current transformer for a substation of claim 1, wherein: the oil discharge port is a one-way valve, and oil in the oil discharge port flows into the other two ports of the three-way valve after the oil discharge port ports of the three-way valve are matched with the one-way valve in an installing mode.

5. The current transformer for a substation of claim 1, wherein: the junction box and the outgoing line are respectively covered with a junction box cover body and a pipeline cover body which are integrally designed, the junction box cover body is of a cylindrical structure with an opening at the bottom and a closed top surface, the side surface of the junction box cover body is communicated with the pipeline cover body, and the pipeline cover body is of a tubular structure with two open ends; opening seams for covering the outgoing lines and the junction box after being broken are formed along the central positions of the pipeline cover body and the junction box cover body; the part of the opening seam positioned on the pipeline cover body is a pipeline opening seam, and the part of the opening seam positioned on the junction box cover body is a cover body opening seam.

6. The current transformer for a substation of claim 5, wherein: and after the junction box cover body and the pipeline cover body are covered with the junction box and the outgoing line, sealant is coated at the position of the opening seam.

7. The current transformer for a substation of claim 5, wherein: the top surface of the junction box cover body is a convex arc cover body.

8. The current transformer for a substation of claim 1, wherein: the diameter of the prefabricated pit is larger than that of the supporting pipe column; a prefabricated plate is prefabricated and fixed at the top edge of the prefabricated pit, and a prefabricated foundation bolt is prefabricated and fixed on the prefabricated plate; the support pipe column clamping device further comprises a butt joint clamping pipe used for clamping and fixing the support pipe column, the butt joint clamping pipe is arranged in a bilateral symmetry mode, and the inner diameter of the symmetrical clamping pipe is smaller than the diameter of the support pipe column; the bottom of the butt joint clamping pipe is a circular table used for being fixed with the precast slab, and a strip-shaped hole corresponding to the precast foundation bolt is formed in the circular table; the positions of the left half part and the right half part of the symmetrical clamping pipe which are butted are radially extended to form a fastening extension plate, and the fastening bolt penetrates through the fastening extension plate to connect the left half part and the right half part of the butted clamping pipe.

9. The current transformer for a substation of claim 8, wherein: reinforcing ribs in inclined connection are distributed between the circular truncated cone of the butt joint clamping pipe and the side face of the butt joint clamping pipe; the number of the foundation bolts is at least four.

10. The current transformer for a substation of claim 8, wherein: concrete is filled between the supporting pipe column and the precast pit; the height of the pre-pit is greater than 1/4 for the support string height; the height of the docking collar is greater than 1/5 the height of the support string.

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