A multi-pulse rectifier transformer with a magnetic shunt core and its installation method

Abstract

The present invention discloses a multi-pulse rectifier transformer with a magnetic shunt core and an installation method thereof, which relates to the technical field of transformers, and includes a base, which is used to place and support the transformer, and also includes a lower clamp, which is arranged on the top of the base and can clamp and fix the lower iron yoke; the lower iron yoke is arranged inside the lower clamp. The present invention also discloses an installation method for a multi-pulse rectifier transformer with a magnetic shunt core, which includes the following steps: monomer cutting, monomer stacking, lower iron yoke fixing, magnetic shunt core and winding installation, upper iron yoke installation and fixing, and base installation. The present invention increases the gap width between two adjacent iron core monomers with a first notch by pushing the expansion block, so that the magnetic shunt core monomer can be easily plugged into the gap between the two adjacent iron core monomers, thereby improving the installation efficiency of the magnetic shunt core and saving labor costs and installation cycles.

Description

Technical Field

[0001] The invention relates to the technical field of transformers, and in particular to a multi-pulse rectifier transformer with a magnetic shunt core and an installation method thereof. Background Art

[0002] A transformer is a device that uses the principle of electromagnetic induction to change AC voltage. Its main components are primary coil, secondary coil and iron core. Its main functions include: voltage conversion, current conversion, impedance conversion, isolation, voltage stabilization (magnetic saturation transformer), etc. Transformers are basic equipment for power transmission and distribution, and are widely used in industry, agriculture, transportation, urban communities and other fields.

[0003] Rectifier transformer is the power transformer of rectifier equipment. The characteristic of rectifier equipment is that the primary side inputs AC, and the secondary side outputs DC after passing through the rectifier element. Current conversion is the general term for the three working modes of rectification, reverse current and frequency conversion, and rectification is the most widely used one. The transformer used as the power supply of the rectifier device is called a rectifier transformer. Most of the rectifier DC power supplies used in industry are obtained from the AC power grid through the rectifier transformer and the rectifier equipment.

[0004] For example, a transformer and assembly method with publication number CN109473265B includes a skeleton, a winding wound on the skeleton, and a yoke iron arranged on the skeleton. An iron core is arranged inside the skeleton, and an enameled layer is installed on the winding. An inner shielding layer is arranged between each layer of winding coils, and an insulating layer is arranged on both sides of the inner shielding layer; an outer shielding layer is also arranged outside the yoke iron. The transformer adds an inner shielding layer between coils of different layers of windings, so that the magnetic induction shielding ability between the entire windings is enhanced. At the same time, the inner shielding layer can effectively reduce the heat accumulation between coils of different layers, so that the heat is quickly discharged; an outer shielding layer is also arranged on the yoke iron, which further enhances the scattered magnetic shielding ability. In addition, the above transformer structure can reduce the potential difference between the windings, reduce the insulation distance between the windings and the winding to the iron core, increase its own heat dissipation surface, improve the heat dissipation effect, reduce the heat interference on the current in the winding, and reduce the current fluctuation.

[0005] Although the transformer in the prior art can improve its heat dissipation effect and enhance its magnetic shielding ability, its performance in preventing multi-point grounding of the transformer core and circulating current inside the clamp is still not ideal. In addition, in terms of transformer installation, it is inconvenient to plug and install the core and the magnetic shunt, which greatly increases the labor cost and installation cycle.

[0006] Therefore, it is necessary to invent a multi-pulse rectifier transformer with a magnetic shunt core and an installation method thereof to solve the above problems. Summary of the invention

[0007] The object of the present invention is to provide a multi-pulse rectifier transformer with a magnetic shunt core and an installation method thereof to solve the problems raised in the above background technology.

[0008] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a multi-pulse rectifier transformer with a magnetic shunt core, comprising a base, the base is used to place and support the transformer, and also comprises a lower clamp, which is arranged on the top of the base and can clamp and fix the lower iron yoke; the lower iron yoke is arranged inside the lower clamp; the iron core is provided in three numbers, and the three iron cores are arranged on the top of the lower iron yoke; the upper clamp is arranged on the top of the iron core and can clamp and fix the upper iron yoke; the upper iron yoke is arranged inside the upper clamp; the magnetic shunt core is provided in multiple numbers and is arranged between two adjacent iron cores; the clamp is arranged on the outer side of the corresponding magnetic shunt core and can clamp and fix the magnetic shunt core and the iron core; the side beam is arranged inside the lower clamp and the upper clamp; the fastening assembly is arranged on both sides of the side beam and can tighten and insulate the lower clamp and the upper clamp; the winding is evenly sleeved on the outside of the iron core.

[0009] Preferably, it also includes iron yoke step pads, which are evenly arranged inside the lower clamp and the upper clamp, and the iron yoke step pads can support and press the lower iron yoke and the upper iron yoke; iron core step pads, which are arranged on the side corresponding to the side beam, and the iron core step pads can support and press the iron core; an upper beam, which is evenly arranged on the top of the upper clamp; and a binding belt, which is tied to the outer periphery of the iron core.

[0010] Preferably, the lower iron yoke includes a plurality of stacked lower iron yoke monomers; the iron core includes a plurality of stacked iron core monomers; the upper iron yoke includes a plurality of stacked upper iron yoke monomers; the magnetic shunt iron core includes a plurality of stacked magnetic shunt iron core monomers; the sides of the two adjacent stacked iron core monomers are respectively provided with a first notch and a second notch, and the depth of the first notch is less than the depth of the second notch, the iron core monomers with the first notch and the iron core monomers with the second notch are alternately stacked, and both ends of each magnetic shunt iron core monomer are adapted to the corresponding first notch or second notch; the thicknesses of the lower iron yoke monomers, the iron core monomers, the upper iron yoke monomers and the magnetic shunt iron core monomers are all kept consistent.

[0011] Preferably, the lower clamp includes a lower low-pressure side clamp, which is fixedly arranged on the top of the base; a lower high-pressure side clamp, which is symmetrically arranged with the lower low-pressure side clamp; the lower low-pressure side clamp and the lower high-pressure side clamp are respectively arranged on both sides of the lower iron yoke, and can clamp and fix the lower iron yoke;

[0012] The upper clamp includes an upper low-pressure side clamp; an upper high-pressure side clamp, which is symmetrically arranged with the upper low-pressure side clamp; the upper low-pressure side clamp and the upper high-pressure side clamp are respectively arranged on both sides of the upper iron yoke, and can clamp and fix the upper iron yoke.

[0013] Preferably, the clamping member includes a clamping side plate, which is clamped on both sides of the corresponding magnetic shunt core; a screw, which passes through the middle of the corresponding magnetic shunt core, and both ends are pressed on both sides of the corresponding clamping side plate by nuts.

[0014] Preferably, the fastening assembly includes screw holes, which are opened on both sides of the side beam; insulating rubber pads, which are arranged on both sides of the side beam; through holes, which are opened on the sides of the lower clamp and the upper clamp; pulp-molded insulating parts, which are arranged inside the through holes, and the end of the pulp-molded insulating parts away from the side beam is a flared structure; a limiting epoxy plate, which is sleeved on the outside of the flared end of the pulp-molded insulating parts; high-density insulating paperboard, which is arranged on one side of the pulp-molded insulating parts and the limiting epoxy plate; a steel pressing plate, which is arranged on one side of the high-density insulating paperboard; a fastening bolt, which passes through the steel pressing plate, the high-density insulating paperboard and the pulp-molded insulating parts in sequence, and its threaded section is threadedly connected to the screw hole.

[0015] A method for installing a multi-pulse rectifier transformer with a magnetic shunt core is also provided, comprising the following steps:

[0016] S1. Single body cutting: Cut out the lower iron yoke single body, iron core single body, upper iron yoke single body and magnetic shunt iron core single body that meet the standards according to the transformer specifications;

[0017] S2. Single-body stacking: Place the lower low-voltage side clamp on the workbench, and stack the lower iron yoke single body and the iron core single body, so as to complete the stacking of the lower iron yoke and the iron core;

[0018] S3, fixing the lower iron yoke: placing the lower high-pressure side clamp on one side of the stacked lower iron yoke, and clamping and fixing the lower iron yoke through the side beam and the fastening assembly;

[0019] S4, installation of magnetic shunt core and winding: install the lower winding, the lower magnetic shunt core, the middle winding, the upper magnetic shunt core and the upper winding on the stacked core monomer in sequence to complete the installation of the magnetic shunt core and winding;

[0020] S5. Installation and fixation of the upper iron yoke: insert multiple upper iron yoke monomers into the top of the iron core to complete the insertion of the upper iron yoke, and then clamp and fix the upper iron yoke through the upper clamp, side beam and fastening assembly. At this point, the installation of the transformer body is completed;

[0021] S6. Installation of base: Place the transformer body installed in S5 on the base, and install and fix the lower clamp and the base to complete the installation of the transformer as a whole.

[0022] Preferably, the S2 further comprises the following steps:

[0023] S21, placing the iron core monomer with the first notch and the lower iron yoke monomer in sequence to complete the placement of the single-layer monomer;

[0024] S22, placing an expansion block on the upper side of the first notch on the core monomer in S21;

[0025] S23, stacking the core monomer and the lower iron yoke monomer with the second notch on the upper side of the core monomer and the lower iron yoke monomer in S21, so as to stack a new layer of monomers, and at this time, the expansion block corresponds to the core monomer with the second notch;

[0026] S24, repeat S21-S23 to complete the stacking of the lower iron yoke and the iron core and the pre-placement of the expansion blocks. After the placement is completed, the front end of each expansion block is clamped between two adjacent iron core monomers with a first notch, and each expansion block corresponds to the corresponding iron core monomer with a second notch.

[0027] Preferably, the S4 further comprises the following steps:

[0028] S41, use a binding belt to bind the stacked iron cores, and turn the iron cores to a vertical state;

[0029] S42, inserting the windings from top to bottom to the bottom of the three cores, and limiting and fixing the windings after they are in place, thereby completing the installation of the lower windings;

[0030] S43, pushing the expansion block so that the rear end of the expansion block is inserted between two adjacent core monomers with first notches, further expanding the gap between the two adjacent first notches, so that the gap between the two adjacent core monomers with first notches is increased;

[0031] S44, insert the two ends of the magnetic shunt core monomer that matches the second notch into the gap between the two expanded core monomers with the first notch on the corresponding side, then pull out the expansion block, the two adjacent core monomers with the first notch will clamp the magnetic shunt core monomer, press down the two ends of the magnetic shunt core monomer to the designated installation position, and complete the plug-in installation between the core monomer with the second notch and the corresponding magnetic shunt core monomer;

[0032] S45, placing the magnetic shunt core monomer that matches the first notch on one side of the magnetic shunt core monomer that matches the second notch in S44, and making both ends of the magnetic shunt core monomer be at the designated installation positions at the first notch, completing the installation between the core monomer with the first notch and the corresponding magnetic shunt core monomer;

[0033] S46, repeat S43-S45 to complete the plug-in installation between the lower magnetic shunt core and the core, and use a clamping member to clamp and fix the lower magnetic shunt core and the core;

[0034] S47, insert the winding into the middle of the three cores from top to bottom, and limit and fix the winding after it is placed in place, so as to complete the installation of the middle winding;

[0035] S48, repeat S43-S46 to complete the plug-in installation between the upper magnetic shunt core and the core, and use a clamp to clamp and fix the upper magnetic shunt core and the core;

[0036] S49, inserting the windings into the upper parts of the three cores from top to bottom, and limiting and fixing the windings after they are in place, thereby completing the installation of the upper windings;

[0037] S410, reinsert the front end of at least one expansion block into between two corresponding adjacent core monomers with first notches, and the front end of the expansion block is located below the corresponding magnetic shunt core monomer after the plug-in installation is completed.

[0038] Preferably, the expansion block includes a pre-embedded portion, which is the front end of the expansion block, which is pre-placed between two adjacent core monomers with a first notch and corresponds to the corresponding core monomer with a second notch; an inclined guide portion, which is fixedly arranged on the rear side of the pre-embedded portion; an expansion portion, which is the rear end of the expansion block, which is fixedly arranged on the rear side of the inclined guide portion and can further expand the gap between the two adjacent core monomers with the first notch; and a pulling portion, which is fixedly arranged on the rear side of the expansion portion and can pull the expansion block out from between the two adjacent core monomers.

[0039] Technical effects and advantages of the present invention:

[0040] 1. The present invention pre-places an expansion block during the process of stacking the iron cores. When the magnetic shunt core is inserted between two iron cores, the expansion block is pushed to increase the width of the gap between two adjacent iron core monomers with the first notch, so that the magnetic shunt core monomer can be easily inserted into the gap between the two iron core monomers. There is no need to use additional tools to pry between the two adjacent iron core monomers, which optimizes the installation method of the magnetic shunt core, avoids damage to the iron core, improves the installation efficiency of the magnetic shunt core, and saves labor costs and installation cycles.

[0041] 2. The present invention places expansion blocks in advance and then uses binding tape to bind the iron core, so that the state of the iron core remains consistent before and after the magnetic shunt core is plugged in and installed. Before plugging in the magnetic shunt core, the staff can directly use the binding tape to bind the iron core with a standard force, thereby ensuring that the iron core is in a stably bound state before and after the magnetic shunt core is plugged in and installed.

[0042] 3. The present invention re-inserts one or more expansion blocks between two corresponding adjacent core monomers with the first notch after completing the insertion and clamping of the magnetic shunt core, so that when the clamping piece becomes loose, the expansion block falls off the core, thereby promptly reminding the staff to check the clamping piece to avoid the clamping piece from losing its clamping function on the core and the magnetic shunt core due to excessive loosening, thereby improving the operating stability of the transformer.

[0043] 4. The present invention inserts the pulp-molded insulating part into the through hole, and then sleeves the limiting epoxy plate on the outside of the expanded end of the pulp-molded insulating part, so that the fastening bolts and the clamps are completely insulated and separated, thereby improving the insulation performance. Its insulation strength is better than that of the traditional epoxy tube insulation method, and it has more excellent performance in preventing multi-point grounding of the transformer core and circulating current inside the clamp.

[0044] 5. The present invention divides the interior of the transformer into 6 core windows through the combination of the lower iron yoke, the iron core, the upper iron yoke and the magnetic shunt iron core, and sets three layers of windings on the three cores respectively, so as to achieve the effect of completing 36-pulse high-voltage phase shifting by the three layers of windings. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0046] Figure 2 It is a schematic diagram of the installation structure of the magnetic shunt core of the present invention.

[0047] Figure 3 It is a schematic diagram of the installation structure of the iron core, the lower iron yoke and the upper iron yoke of the present invention.

[0048] Figure 4It is a schematic diagram of the installation structure of the lower low-pressure side clamp and the lower high-pressure side clamp of the present invention.

[0049] Figure 5 It is a schematic diagram of the installation structure of the upper low-pressure side clamp and the upper high-pressure side clamp of the present invention.

[0050] Figure 6 It is a schematic structural diagram of the fastening assembly of the present invention.

[0051] Figure 7 It is a schematic diagram of the planar structure of the iron core, the lower iron yoke and the upper iron yoke of the present invention.

[0052] Figure 8 It is a schematic structural diagram of the clamping member of the present invention.

[0053] Fig. 9 This is a schematic diagram of the state in which the expansion block of the present invention is pre-placed.

[0054] Fig.10 It is a schematic diagram of the cooperation between the expansion block and the first notch and the second notch of the present invention.

[0055] Fig.11 It is a structural schematic diagram of the expansion block of the present invention.

[0056] Fig.12 It is a schematic diagram of the cooperation between the pre-embedded part and the iron core monomer of the present invention.

[0057] Fig.13 It is a schematic diagram of the cooperation between the expansion support part and the iron core monomer of the present invention.

[0058] In the figure: 1, base; 2, lower clamp; 3, lower iron yoke; 4, iron core; 6, upper clamp; 7, upper iron yoke; 8, magnetic shunt iron core; 9, clamp; 10, side beam; 11, fastening assembly; 12, winding; 13, iron yoke step pad; 14, iron core step pad; 15, upper beam; 16, binding belt; 18, expansion block; 201, lower low-voltage side clamp; 202, lower high-voltage side clamp; 301, lower iron yoke monomer; 401, iron core monomer; 601, upper low-voltage side clamp; 602, upper high-voltage side clamp; 701, upper iron Yoke monomer; 801, magnetic shunt core monomer; 901, clamping side plate; 902, screw; 903, nut; 1101, screw hole; 1102, insulating rubber pad; 1103, through hole; 1104, pulp molding insulation; 1105, limiting epoxy board; 1106, high-density insulating paperboard; 1107, steel pressure plate; 1108, fastening bolt; 1701, first notch; 1702, second notch; 1801, pre-embedded part; 1802, inclined guide part; 1803, expansion part; 1804, pulling part. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] Embodiment 1, the present invention provides as follows Figures 1 to 13 A multi-pulse rectifier transformer with a magnetic shunt core is shown, comprising a base 1, which is used to place and support the transformer.

[0061] It also includes a lower clamp 2 which is arranged on the top of the base 1 and can clamp and fix the lower iron yoke 3.

[0062] Specifically, the lower clamp 2 includes a lower low-pressure side clamp 201, which is fixedly arranged on the top of the base 1; a lower high-pressure side clamp 202, which is symmetrically arranged with the lower low-pressure side clamp 201; the lower low-pressure side clamp 201 and the lower high-pressure side clamp 202 are respectively arranged on both sides of the lower iron yoke 3, so as to ensure the stability of the lower iron yoke 3 during operation.

[0063] The lower iron yoke 3 is arranged inside the lower clamp 2 and includes a plurality of stacked lower iron yoke monomers 301 .

[0064] There are three iron cores 4 , which are arranged on the top of the lower iron yoke 3 . The iron core 4 includes a plurality of stacked iron core monomers 401 .

[0065] Specifically, the outer periphery of the core 4 is provided with binding straps 16, which can ensure the structural stability of the core 4 and prevent the core 4 from displacement or deformation, thereby reducing the vibration and noise of the core 4 during operation and ensuring the continuity of the magnetic circuit and the electrical performance of the transformer.

[0066] The upper clamp 6 is arranged on the top of the iron core 4 and can clamp and fix the upper iron yoke 7.

[0067] Specifically, the upper clamp 6 includes an upper low-pressure side clamp 601; an upper high-pressure side clamp 602, which is symmetrically arranged with the upper low-pressure side clamp 601; the upper low-pressure side clamp 601 and the upper high-pressure side clamp 602 are respectively arranged on both sides of the upper iron yoke 7, so as to ensure the stability of the upper iron yoke 7 during operation.

[0068] The upper iron yoke 7 is arranged inside the upper clamp 6 and includes a plurality of upper iron yoke monomers 701 which are stacked.

[0069] There are multiple magnetic shunt cores 8 , which are arranged between two adjacent cores 4 . The magnetic shunt core 8 includes multiple stacked magnetic shunt core monomers 801 .

[0070] It should be noted that the thickness of the lower yoke monomer 301, the core monomer 401, the upper yoke monomer 701 and the magnetic shunt core monomer 801 are all consistent; the sides of the two adjacent stacked core monomers 401 are respectively provided with a first notch 1701 and a second notch 1702, and the depth of the first notch 1701 is less than the depth of the second notch 1702, and the core monomers 401 with the first notch 1701 and the core monomers 401 with the second notch 1702 are alternately stacked; both ends of each magnetic shunt core monomer 801 are matched with the corresponding first notch 1701 or second notch 1702, and positioning holes can be provided on the lower yoke monomer 301, the core monomer 401, the upper yoke monomer 701 and the magnetic shunt core monomer 801 to facilitate positioning during the stacking process, thereby improving the stacking speed and effect.

[0071] The clamping member 9 is arranged on the outer side of the corresponding magnetic shunt core 8 and can clamp and fix the magnetic shunt core 8 and the core 4.

[0072] Specifically, the clamping member 9 includes a clamping side plate 901, which is clamped on both sides of the corresponding magnetic shunt core 8; a screw 902, which passes through the middle of the corresponding magnetic shunt core 8, and both ends are respectively pressed on both sides of the corresponding clamping side plate 901 by nuts 903; through the cooperation of the screw 902 and the nut 903, the clamping side plate 901 can be pressed on both sides of the magnetic shunt core 8, thereby improving the structural stability of the magnetic shunt core 8 during operation.

[0073] The side beam 10 is arranged inside the lower clamp 2 and the upper clamp 6. Two side beams 10 are symmetrically arranged at both ends of the lower clamp 2 and the upper clamp 6. The side beam 10 is used to tighten the lower clamp 2 and the upper clamp 6 to ensure the clamping effect of the lower clamp 2 on the lower iron yoke 3 and the upper clamp 6 on the upper iron yoke 7.

[0074] The fastening assembly 11 is disposed on both sides of the side beam 10 and can tighten and insulate the lower clamp 2 and the upper clamp 6 .

[0075] Specifically, the fastening assembly 11 includes a screw hole 1101, which is opened on both sides of the side beam 10; an insulating rubber pad 1102, which is arranged on both sides of the side beam 10; a through hole 1103, which is opened on the side of the lower clamp 2 and the upper clamp 6, and the aperture of the through hole 1103 is larger than the aperture of the screw hole 1101; a pulp-molded insulating member 1104, which is arranged inside the through hole 1103, and the end of the pulp-molded insulating member 1104 away from the side beam 10 is a flared structure; a limiting epoxy plate 1105, which is sleeved on the outer side of the flared end of the pulp-molded insulating member 1104; the high-density insulating paperboard 1106, which is arranged on one side of the pulp-molded insulating member 1104 and the limiting epoxy plate 1105; the steel pressing plate 1107, which is arranged on one side of the high-density insulating paperboard 1106; the fastening bolt 1108, which passes through the steel pressing plate 1107, the high-density insulating paperboard 1106 and the pulp-molded insulating member 1104 in sequence, and its threaded section is threadedly connected with the screw hole 1101.

[0076] When the upper clamp 6 needs to be tightened, the side beam 10 is placed between the upper low-voltage side clamp 601 and the upper high-voltage side clamp 602. At this time, the insulating rubber pads 1102 on both sides of the side beam 10 are respectively attached to the inner sides of the upper low-voltage side clamp 601 and the upper high-voltage side clamp 602. The pulp-molded insulating member 1104 is inserted into the interior of the through hole 1103, and the flared end of the pulp-molded insulating member 1104 is abutted against the outer sides of the upper low-voltage side clamp 601 and the upper high-voltage side clamp 602. The limiting epoxy plate 1105 is sleeved on the outer side of the flared end. On the other side, high-density insulating paperboard 1106 and steel pressure plate 1107 are placed on the outside of the limiting epoxy plate 1105 in turn, and finally, fastening bolts 1108 are used to pass through the steel pressure plate 1107, high-density insulating paperboard 1106 and pulp-molded insulating member 1104 in turn, and the threaded section is screwed into the screw hole 1101, so as to achieve complete insulation between the upper clamp 6 and the side beam 10 while tightening the upper low-voltage side clamp 601 and the upper high-voltage side clamp 602, thereby improving the insulation reliability and preventing the transformer from being grounded at multiple points.

[0077] Similarly, through the above operation steps, the lower clamp 2 is tightened and insulated.

[0078] It should be noted that the upper beam 15 and the upper clamp 6 , and the base 1 and the lower clamp 2 can be fixed and insulated by the above-mentioned method, which will not be described in detail here.

[0079] The winding 12 is evenly sleeved on the outside of the iron core 4. The winding 12 is composed of a low-voltage coil and a high-voltage coil sleeved on each other. The specific structure of the winding 12 inside the transformer is prior art and will not be repeated here.

[0080] There are multiple iron yoke step pads 13, which are evenly arranged inside the lower clamp 2 and the upper clamp 6. Each iron yoke step pad 13 is fixedly connected to the corresponding lower low-pressure side clamp 201, lower high-pressure side clamp 202, upper low-pressure side clamp 601, and upper high-pressure side clamp 602 through connecting parts. The iron yoke step pads 13 can support and press the lower iron yoke 3 and the upper iron yoke 7.

[0081] There are a plurality of core step spacers 14 , all of which are fixedly disposed on one side of the corresponding side beam 10 . The core step spacers 14 can support and press the core 4 .

[0082] The upper beam 15 is evenly arranged on the top of the upper clamp 6 .

[0083] When installing the above-mentioned transformer, the lower low-voltage side clamp 201 is placed at a designated position on the workbench, and the lower iron yoke monomer 301 and the iron core monomer 401 are stacked, and then the lower high-voltage side clamp 202 is placed on one side of the stacked lower iron yoke 3, and the lower iron yoke 3 is clamped and fixed by the side beam 10 and the fastening assembly 11; then the stacked lower iron yoke 3 and the iron core 4 are flipped to a vertical state, and the winding 12 is inserted into the bottom of the iron core 4, and then a plurality of magnetic shunt iron core monomers 801 are inserted between two adjacent iron cores 4, and then the winding 12 is inserted into the middle of the iron core 4 and the magnetic shunt iron core monomer 801 is inserted again, and finally the winding 12 is inserted into the top of the iron core 4. After the winding 12 is installed, a plurality of upper iron yoke monomers 701 are inserted into the top of the iron core 4 to complete the insertion of the upper iron yoke 7, and then the upper iron yoke 7 is clamped and fixed by the upper clamp 6, the side beam 10 and the fastening assembly 11.

[0084] In summary, by providing the lower iron yoke 3, the iron core 4, the upper iron yoke 7 and the magnetic shunt iron core 8, the interior of the transformer is divided into 6 iron core windows, and three layers of windings 12 are respectively mounted on the three iron cores 4, thereby achieving the effect of the three layers of windings 12 completing 36-pulse high-voltage phase shifting.

[0085] By inserting the pulp-molded insulating member 1104 into the through hole 1103 and then sleeve-fitting the limiting epoxy plate 1105 on the outside of the flared end of the pulp-molded insulating member 1104, the fastening bolt 1108 is completely insulated from the clamp, thereby improving the insulation performance. The insulation strength is better than the traditional epoxy tube insulation method, and it has more excellent performance in preventing multi-point grounding of the transformer and circulating current inside the clamp.

[0086] In the second embodiment, the staff found in the long-term transformer installation process that after the lower iron yoke 3 and the iron core 4 are stacked, the iron core 4 is first tied with the binding belt 16, and then the transformer iron core 4 and the magnetic shunt iron core 8 are plugged and installed. If the binding force of the binding belt 16 on the iron core 4 is small, it is impossible to have a relatively stable binding effect on the iron core 4. If the binding force of the binding belt 16 on the iron core 4 is directly adjusted to the standard level, the binding belt 16 will tighten the iron core 4, resulting in a close fit between adjacent iron core monomers 401, so that the gap between two adjacent iron core monomers 401 with the first notch 1701 is close. To reduce, that is, the gap between the two core monomers 401 is smaller than the thickness of the magnetic shunt core monomer 801, the staff needs to frequently use other tools to lift the two core monomers 401 close to each other out of the gap so that the magnetic shunt core monomer 801 can be plugged in. When the core monomer 401 is pried with a tool, on the one hand, since the gap between the two core monomers 401 is small, it is not convenient to insert the tool into the gap for prying. On the other hand, frequent use of tools for prying can easily cause damage to the core monomer 401. At the same time, it also greatly reduces the work efficiency of the staff and prolongs the installation period of the transformer. Therefore, the present invention also provides an installation method for a multi-pulse rectifier transformer with a magnetic shunt core, comprising the following steps:

[0087] S1. Monomer cutting: cutting out the lower yoke monomer 301, the core monomer 401, the upper yoke monomer 701 and the magnetic shunt core monomer 801 that meet the standards according to the transformer specifications;

[0088] S2, monomer stacking: placing the lower low-voltage side clamp 201 on the workbench, and stacking the lower iron yoke monomer 301 and the iron core monomer 401, thereby completing the stacking of the lower iron yoke 3 and the iron core 4;

[0089] S3, fixing the lower iron yoke 3: placing the lower high-pressure side clamp 202 on one side of the stacked lower iron yoke 3, and clamping and fixing the lower iron yoke 3 through the side beam 10 and the fastening assembly 11;

[0090] S4, installation of magnetic shunt core 8 and winding 12: sequentially install lower winding 12, lower magnetic shunt core 8, middle winding 12, upper magnetic shunt core 8 and upper winding 12 on the stacked core monomer 401, completing the installation of magnetic shunt core 8 and winding 12;

[0091] S5, installation and fixation of the upper iron yoke 7: insert multiple upper iron yoke monomers 701 into the top of the iron core 4 to complete the insertion of the upper iron yoke 7, and then clamp and fix the upper iron yoke 7 through the upper clamp 6, the side beam 10 and the fastening assembly 11, so that the installation of the transformer body is completed;

[0092] S6. Installation of the base 1: Place the transformer body installed in S5 on the base 1, and install and fix the lower clamp 2 and the base 1 to complete the installation of the entire transformer.

[0093] Specifically, S2 further includes the following steps:

[0094] S21, placing the iron core monomer 401 with the first notch 1701 and the lower iron yoke monomer 301 in sequence to complete the placement of the single-layer monomer;

[0095] S22, placing an expansion block 18 on the upper side of the first notch 1701 on the core monomer 401 in S21;

[0096] S23, in S21, the core monomer 401 and the lower iron yoke monomer 301 with the second notch 1702 are stacked in sequence on the upper side of the core monomer 401 and the lower iron yoke monomer 301, so as to stack a new layer of monomers, and at this time, the expansion block 18 corresponds to the core monomer 401 with the second notch 1702;

[0097] S24, repeat S21-S23 to complete the stacking of the lower iron yoke 3 and the iron core 4 and the pre-placement of the expansion block 18. After the placement is completed, the front end of each expansion block 18 is clamped between two adjacent iron core monomers 401 with a first notch 1701, and each expansion block 18 corresponds to the corresponding iron core monomer 401 with a second notch 1702.

[0098] Meanwhile, S4 further comprises the following steps:

[0099] S41, using the binding belt 16 to bind the stacked iron core 4, and turning the iron core 4 to a vertical state;

[0100] S42, inserting the winding 12 from top to bottom to the bottom of the three cores 4, and limiting and fixing the winding 12 after it is placed in place, so as to complete the installation of the lower winding 12;

[0101] S43, pushing the expansion block 18, so that the rear end of the expansion block 18 is inserted between two adjacent iron core monomers 401 with first notches 1701, further expanding the gap between the two adjacent first notches 1701, so that the gap between the two adjacent iron core monomers 401 with first notches 1701 is increased;

[0102] S44, insert the two ends of the magnetic shunt core monomer 801 that match the second notch 1702 into the gap between the two expanded core monomers 401 with the first notch 1701 on the corresponding side, then pull out the expansion block 18, the two adjacent core monomers 401 with the first notch 1701 will clamp the magnetic shunt core monomer 801, press the two ends of the magnetic shunt core monomer 801 down to the designated installation position, and complete the plug-in installation between the core monomer 401 with the second notch 1702 and the corresponding magnetic shunt core monomer 801;

[0103] S45, placing the magnetic shunt core monomer 801 matched with the first notch 1701 on one side of the magnetic shunt core monomer 801 matched with the second notch 1702 in S44, and making the two ends of the magnetic shunt core monomer 801 at the designated installation positions of the first notch 1701, completing the installation between the core monomer 401 with the first notch 1701 and the corresponding magnetic shunt core monomer 801;

[0104] S46, repeat S43-S45 to complete the plug-in installation between the lower magnetic shunt core 8 and the iron core 4, and use the clamping member 9 to clamp and fix the lower magnetic shunt core 8 and the iron core 4;

[0105] S47, insert the winding 12 into the middle of the three cores 4 from top to bottom, and limit and fix the winding 12 after it is placed in place, so as to complete the installation of the middle winding 12;

[0106] S48, repeat S43-S46 to complete the plug-in installation between the upper magnetic shunt core 8 and the core 4, and use the clamping member 9 to clamp and fix the upper magnetic shunt core 8 and the core 4;

[0107] S49, inserting the winding 12 into the upper part of the three cores 4 from top to bottom, and limiting and fixing the winding 12 after it is placed in place, so as to complete the installation of the upper winding 12;

[0108] S410, reinsert the front end of at least one expansion block 18 between two corresponding adjacent core monomers 401 with first notches 1701, and locate it below the corresponding magnetic shunt core monomer 801 after the plug-in installation is completed.

[0109] More specifically, the expansion block 18 includes a pre-embedded portion 1801, which is the front end of the expansion block 18 and is pre-placed between two adjacent core monomers 401 with a first notch 1701, and corresponds to the corresponding core monomer 401 with a second notch 1702; an inclined guide portion 1802, which is fixedly arranged on the rear side of the pre-embedded portion 1801 and is arranged as a smooth inclined structure, which can facilitate the expansion block 18 to further slide between the two adjacent core monomers 401 with the first notch 1701; an expansion portion 1803, which is the rear end of the expansion block 18 and is fixedly arranged on the rear side of the inclined guide portion 1802 and can further expand the gap between the two adjacent core monomers 401 with the first notch 1701; a pulling portion 1804, which is fixedly arranged on the rear side of the expansion portion 1803 and can pull the expansion block 18 out from between the two adjacent core monomers 401.

[0110] It should be noted that the expansion block 18 as a whole is a conical structure that is thin at the front and thick at the back, wherein the thickness of the pre-embedded portion 1801 is the same as the thickness of the magnetic shunt core monomer 801, and the thickness of the expansion portion 1803 is set to 1.5 times that of the magnetic shunt core monomer 801.

[0111] Specifically, when the iron core 4 and the magnetic shunt iron core 8 are plugged and installed, the iron core 4 is first stacked. During this process, the pre-embedded portion 1801 is clamped between two adjacent iron core monomers 401 with first notches 1701. At this time, the gap width between the two iron core monomers 401 is the same as the thickness of the magnetic shunt iron core monomer 801, and the inclined guide portion 1802 and the expansion portion 1803 are both located on the outside of the corresponding first notch 1701. Fig.12 When the expansion block 18 is pushed so that the inclined guide portion 1802 guides the expansion portion 1803 to be inserted between two adjacent core monomers 401 with a first notch 1701, the gap width between the two core monomers 401 is expanded to 1.5 times the thickness of the magnetic shunt core monomer 801, as shown Fig.13 As shown, the magnetic shunt core monomer 801 can now be easily inserted between the two corresponding core monomers 401 , and the inclined guide portion 1802 can guide the expansion portion 1803 to be smoothly inserted between the two adjacent core monomers 401 .

[0112] More specifically, after completing the plug-in installation between the iron core 4 and the magnetic shunt core 8 and clamping and fixing the iron core 4 and the magnetic shunt core 8 with the clamping piece 9, an expansion block 18 is reinserted between two adjacent iron core monomers 401 with the first notch 1701, and the expansion block 18 is located below the corresponding magnetic shunt core monomer 801 after the plug-in installation is completed. Since the magnetic shunt core monomer 801 has been plug-in installed between the two adjacent iron core monomers 401 with the first notch 1701 at this time, and the magnetic shunt core monomer 801 has the same thickness as the pre-embedded portion 1801, the pre-embedded portion 1801 can be directly inserted below the corresponding magnetic shunt core monomer 801 and clamped between the corresponding two adjacent iron core monomers 401 with the first notch 1701. It should be noted that at this time, the pre-embedded portion 1801 only needs a part of its front end to be clamped between the above two core monomers 401. There is friction between the above two core monomers 401 and the pre-embedded portion 1801. The two core monomers 401 clamp the pre-embedded portion 1801 so that the expansion block 18 will not fall off automatically. During the operation of the transformer, when the screw 902 and the nut 903 in the clamping member 9 become loose, the clamping effect of the clamping member 9 on the magnetic shunt core 8 and the core 4 is weakened, and the friction between the core monomer 401 and the pre-embedded portion 1801 is reduced, so that the pre-embedded portion 1801 can no longer be stably clamped and fixed between the above two core monomers 401. In addition, a certain degree of vibration will be generated during the operation of the transformer, and the expansion block 18 will fall off the core 4. It should be noted that multiple expansion blocks 18 can also be re-inserted between the corresponding two adjacent core monomers 401 with the first notch 1701.

[0113] To summarize, by pre-placing the expansion block 18 during the process of stacking the core 4 and then using the binding strap 16 to bind the core 4, the state of the core 4 with the expansion block 18 pre-placed is consistent with the state of the core 4 that is subsequently plugged in and installed with the magnetic shunt core 8. Therefore, the staff can directly use the binding strap 16 to bind the core 4 with a standard force, thereby ensuring the effect of the binding strap 16 on stably binding the core 4, and ensuring that the core 4 is in a stably bound state before and after the magnetic shunt core 8 is plugged in and installed.

[0114] By pushing the rear end of the pre-placed expansion block 18 into between two adjacent core monomers 401 with the first notch 1701, the width of the gap between the two core monomers 401 is increased, so that the magnetic shunt core monomer 801 can be easily plugged into the gap between the two core monomers 401, and then the expansion block 18 is pulled out to complete the plugging of the magnetic shunt core monomer 801. There is no need for the staff to use additional tools to pry the two core monomers 401, thereby avoiding damage to the core monomer 401. At the same time, it also speeds up the staff's plug-in installation efficiency of the magnetic shunt core 8 and shortens the installation period of the transformer.

[0115] After completing the plug-in installation and clamping fixation between the iron core 4 and the magnetic shunt iron core 8, one or more expansion blocks 18 are re-inserted between the corresponding two adjacent iron core monomers 401 with the first notch 1701, and the one or more expansion blocks 18 are located below the corresponding magnetic shunt iron core monomers 801 after the plug-in installation is completed. When the transformer works for a long time in a vibrating environment, the nut 903 on the clamping member 9 will loosen, causing the clamping effect of the clamping member 9 on the iron core 4 and the magnetic shunt iron core 8 to decrease. However, it is difficult to directly determine whether the nut 903 is loose by observing it during daily inspection and maintenance, so safety hazards cannot be discovered in time. Through the above operation, when the nut 903 on the clamping piece 9 is loosened to a certain extent, the clamping effect of the clamping piece 9 on the iron core 4 and the magnetic shunt iron core 8 is reduced, which will cause the clamping force of the iron core monomer 401 on the front end of the expansion block 18 to weaken. Continuous and long-term vibration from the outside will cause the expansion block 18 to fall off the iron core 4. This will promptly remind the inspection personnel to check the status of the clamping piece 9 to avoid the clamping piece 9 from losing its clamping function on the iron core 4 and the magnetic shunt iron core 8 due to excessive loosening, thereby improving the operating stability of the transformer.

[0116] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-pulse rectifier transformer with a magnetic shunt core, comprising a base (1), wherein the base (1) is used to place and support the transformer, and is characterized in that: Also includes: A lower clamp (2) disposed on the top of the base (1) and capable of clamping and fixing the lower iron yoke (3); A lower iron yoke (3) arranged inside the lower clamp (2), the lower iron yoke (3) comprising a plurality of stacked lower iron yoke monomers (301); An iron core (4), the number of which is three, the three iron cores (4) being arranged on the top of the lower iron yoke (3), the iron core (4) comprising a plurality of stacked iron core monomers (401); An upper clamp (6) disposed on the top of the iron core (4) and capable of clamping and fixing the upper iron yoke (7); An upper iron yoke (7) arranged inside the upper clamp (6), the upper iron yoke (7) comprising a plurality of upper iron yoke monomers (701) stacked and arranged; A plurality of magnetic shunt iron cores (8) are provided and arranged between two adjacent iron cores (4); the magnetic shunt iron core (8) comprises a plurality of magnetic shunt iron core monomers (801) arranged in a stacked manner; A clamping member (9) is arranged on the outer side of the corresponding magnetic shunt core (8) and is capable of clamping and fixing the magnetic shunt core (8) and the core (4); A side beam (10) disposed inside the lower clamping piece (2) and the upper clamping piece (6); A fastening assembly (11), which is arranged on both sides of the side beam (10) and is capable of tightening and insulating the lower clamp (2) and the upper clamp (6); A winding (12) uniformly sleeved on the outside of the iron core (4); The sides of the two adjacently stacked iron core monomers (401) are respectively provided with a first notch (1701) and a second notch (1702), and the depth of the first notch (1701) is less than the depth of the second notch (1702); the iron core monomers (401) provided with the first notch (1701) and the iron core monomers (401) provided with the second notch (1702) are alternately stacked, and both ends of each magnetic shunt iron core monomer (801) are adapted to the corresponding first notch (1701) or second notch (1702); The thicknesses of the lower iron yoke monomer (301), the iron core monomer (401), the upper iron yoke monomer (701) and the magnetic shunt iron core monomer (801) are all kept consistent; The expansion block (18) comprises: A pre-embedded portion (1801), which is the front end of the expansion block (18), is pre-placed between two adjacent iron core monomers (401) with first notches (1701), and corresponds to the iron core monomer (401) with a corresponding second notch (1702); An inclined guide portion (1802) fixedly disposed on the rear side of the pre-embedded portion (1801); An expansion portion (1803), which is the rear end of the expansion block (18), is fixedly arranged on the rear side of the inclined guide portion (1802) and is capable of further expanding the gap between two adjacent iron core monomers (401) with first notches (1701); The lifting portion (1804) is fixedly arranged on the rear side of the expansion portion (1803) and is capable of pulling the expansion block (18) out from between two adjacent iron core monomers (401).

2. A multi-pulse rectifier transformer with a magnetic shunt core according to claim 1, characterized in that: Also includes: Iron yoke step pads (13) are evenly arranged inside the lower clamp (2) and the upper clamp (6), and the iron yoke step pads (13) are capable of supporting and pressing the lower iron yoke (3) and the upper iron yoke (7); An iron core step pad (14) disposed on a side corresponding to the side beam (10), the iron core step pad (14) being capable of supporting and pressing the iron core (4); An upper beam (15) evenly arranged on the top of the upper clamp (6); A binding belt (16) is tied to the outer periphery of the iron core (4).

3. A multi-pulse rectifier transformer with a magnetic shunt core according to claim 2, characterized in that: The lower clamp (2) comprises: A lower low-pressure side clamp (201) fixedly disposed on the top of the base (1); A lower high-pressure side clamp (202), which is symmetrically arranged with respect to the lower low-pressure side clamp (201); The lower low-pressure side clamp (201) and the lower high-pressure side clamp (202) are respectively arranged on both sides of the lower iron yoke (3), and are capable of clamping and fixing the lower iron yoke (3); The upper clamp (6) comprises: Upper low pressure side clamp (601); An upper high-pressure side clamp (602) which is symmetrically arranged with respect to the upper low-pressure side clamp (601); The upper low-pressure side clamp (601) and the upper high-pressure side clamp (602) are respectively arranged on both sides of the upper iron yoke (7), and can clamp and fix the upper iron yoke (7).

4. A multi-pulse rectifier transformer with a magnetic shunt core according to claim 3, characterized in that: The clamping member (9) comprises: A clamping side plate (901) which is clamped and arranged on two sides corresponding to the magnetic shunt iron core (8); A screw rod (902) passes through the middle of the corresponding magnetic shunt core (8), and two ends thereof are respectively pressed against two sides of the corresponding clamping side plate (901) through nuts (903).

5. A multi-pulse rectifier transformer with a magnetic shunt core according to claim 4, characterized in that: The fastening assembly (11) comprises: Screw holes (1101) are provided on both sides of the side beam (10); Insulating rubber pads (1102) arranged on both sides of the side beam (10); A through hole (1103) is formed on the side surfaces of the lower clamping piece (2) and the upper clamping piece (6); A pulp-molded insulating member (1104) is arranged inside the through hole (1103), and one end of the pulp-molded insulating member (1104) away from the side beam (10) is a flared structure; A limiting epoxy plate (1105) sleeved on the outside of the flared end of the pulp-molded insulating member (1104); A high-density insulating paperboard (1106), which is arranged on one side of the pulp-molded insulating member (1104) and the limiting epoxy board (1105); A steel pressing plate (1107) disposed on one side of the high-density insulating paperboard (1106); A fastening bolt (1108) passes through the steel pressing plate (1107), the high-density insulating paperboard (1106), and the pulp-molded insulating member (1104) in sequence, and a threaded section thereof is threadedly connected to the screw hole (1101).

6. A method for installing a multi-pulse rectifier transformer with a magnetic shunt core, applied to the multi-pulse rectifier transformer with a magnetic shunt core as claimed in claim 5, characterized in that: The following steps are involved: S1. Single-body cutting: Cutting out lower iron yoke single bodies (301), iron core single bodies (401), upper iron yoke single bodies (701) and magnetic shunt iron core single bodies (801) that meet the standards according to the transformer specifications; S2, single body stacking: placing the lower low-voltage side clamp (201) on a workbench, and stacking the lower iron yoke single body (301) and the iron core single body (401), thereby completing the stacking of the lower iron yoke (3) and the iron core (4); S3, fixing the lower iron yoke (3): placing the lower high-pressure side clamp (202) on one side of the stacked lower iron yoke (3), and clamping and fixing the lower iron yoke (3) through the side beam (10) and the fastening assembly (11); S4, installation of the magnetic shunt core (8) and the winding (12): sequentially installing the lower winding (12), the lower magnetic shunt core (8), the middle winding (12), the upper magnetic shunt core (8) and the upper winding (12) on the stacked core monomer (401), thereby completing the installation of the magnetic shunt core (8) and the winding (12); S5, installing and fixing the upper iron yoke (7): inserting a plurality of upper iron yoke units (701) into the top end of the iron core (4) to complete the insertion of the upper iron yoke (7), and then clamping and fixing the upper iron yoke (7) through the upper clamp (6), the side beam (10) and the fastening assembly (11), thereby completing the installation of the transformer body; S6. Installation of the base (1): Place the transformer body installed in S5 on the base (1), and install and fix the lower clamp (2) and the base (1) to complete the installation of the entire transformer.

7. The method for installing a multi-pulse rectifier transformer with a magnetic shunt core according to claim 6, characterized in that: S2 further comprises the following steps: S21, placing the iron core monomer (401) with the first notch (1701) and the lower iron yoke monomer (301) in sequence to complete the placement of the single-layer monomers; S22, placing an expansion block (18) on the upper side of the first notch (1701) on the iron core unit (401) in S21; S23, stacking the core monomer (401) and the lower iron yoke monomer (301) with the second notch (1702) on the upper side of the core monomer (401) and the lower iron yoke monomer (301) in S21, thereby stacking a new layer of monomers, and at this time, the expansion block (18) corresponds to the core monomer (401) with the second notch (1702); S24, repeat S21-S23 to complete the stacking of the lower iron yoke (3) and the iron core (4) and the pre-placement of the expansion block (18), and after the placement is completed, the front end of each expansion block (18) is clamped between two adjacent iron core monomers (401) with a first notch (1701), and each expansion block (18) corresponds to the corresponding iron core monomer (401) with a second notch (1702).

8. The method for installing a multi-pulse rectifier transformer with a magnetic shunt core according to claim 7, characterized in that: S4 further comprises the following steps: S41, using a binding belt (16) to bind the stacked iron core (4), and turning the iron core (4) to a vertical state; S42, inserting the winding (12) from top to bottom into the bottom of the three iron cores (4), and limiting and fixing the winding (12) after it is in place, thereby completing the installation of the lower winding (12); S43, pushing the expansion block (18) so that the rear end of the expansion block (18) is inserted between two adjacent iron core monomers (401) with first notches (1701), further expanding the space between the two adjacent first notches (1701), thereby increasing the gap between the two adjacent iron core monomers (401) with first notches (1701); S44, inserting the two ends of the magnetic shunt core monomer (801) matched with the second notch (1702) into the gap between the two expanded core monomers (401) with the first notch (1701) on the corresponding side, and then pulling out the expansion block (18), the two adjacent core monomers (401) with the first notch (1701) will clamp the magnetic shunt core monomer (801), and press the two ends of the magnetic shunt core monomer (801) down to the designated installation position, thereby completing the plug-in installation between the core monomer (401) with the second notch (1702) and the corresponding magnetic shunt core monomer (801); S45, placing the magnetic shunt core monomer (801) matched with the first notch (1701) on one side of the magnetic shunt core monomer (801) matched with the second notch (1702) in S44, and making the two ends of the magnetic shunt core monomer (801) be located at the designated installation positions at the first notch (1701), thereby completing the installation between the core monomer (401) with the first notch (1701) and the corresponding magnetic shunt core monomer (801); S46, repeating S43-S45 to complete the plug-in installation between the lower magnetic shunt core (8) and the core (4), and using the clamping member (9) to clamp and fix the lower magnetic shunt core (8) and the core (4); S47, inserting the winding (12) into the middle of the three iron cores (4) from top to bottom, and limiting and fixing the winding (12) after it is placed in place, thereby completing the installation of the middle winding (12); S48, repeating S43-S46 to complete the plug-in installation between the upper magnetic shunt core (8) and the core (4), and using the clamping member (9) to clamp and fix the upper magnetic shunt core (8) and the core (4); S49, inserting the winding (12) into the upper part of the three iron cores (4) from top to bottom, and limiting and fixing the winding (12) after it is placed in place, thereby completing the installation of the upper winding (12); S410, reinserting the front end of at least one expansion block (18) between two corresponding adjacent iron core monomers (401) with first notches (1701), and positioning the front end below the corresponding magnetic shunt iron core monomer (801) that has been plugged in and installed.

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