A dry-type transformer assembly process

Abstract

This invention relates to an assembly process for a dry-type transformer, characterized by the following specific assembly steps: pre-assembly preparation; removal of the upper yoke; support insulation binding; placement of coil under-coil pads; hoisting of the high-voltage coil; placement of the insulation cylinder; hoisting of the low-voltage coil; placement of support pads; assembly of the upper yoke; clamping of the yoke clamps; application of core insulating varnish; placement of insulation blocks on the coils; coil tightening; lead wire assembly; transformer testing; and assembly of accessories and nameplates. The assembly process for the dry-type transformer is simple to operate, with a reasonable process sequence, facilitating later maintenance, reducing the labor intensity of workers, and avoiding excessive welding and painting processes during installation, thus shortening the assembly production cycle and saving labor costs. The high and low voltage resin coils exhibit good installation stability and are less prone to displacement during transportation, preventing changes in the relative spacing between the high and low voltage resin coils and the core. Precise control of the installation dimensions of each component ensures assembly accuracy.

Description

Technical Field

[0001] This invention relates to the field of dry-type transformer assembly technology, and more particularly to a dry-type transformer assembly process. Background Technology

[0002] Currently, the structure of a dry-type transformer typically consists of three resin-cast coils (high and low voltage) mounted on the core column. The lower yoke of the core rests on a supporting channel steel and is secured by four fastening screws in a lower clamp. Three x four lower pads and inserts are placed on the lower clamp. The high and low voltage resin-cast coils are placed on the lower pads and inserts. The lower clamp and upper clamp are connected by three pull plates on each side of the core and upper and lower pins on the pull plates. The upper clamp has four lifting rings. The lifting weight of the entire transformer is borne by six pull plates. The upper clamp is secured to the upper yoke of the core by four fastening screws and the four upper pads and inserts on the three resin-cast coils (high and low voltage) are pressed together by pressure pins, thereby fixing and maintaining the position of the high and low voltage resin coils.

[0003] In some cases, after being transported to the site, dry-type transformers of this traditional structure may experience problems such as broken high-voltage connecting rods and cracked high-voltage terminals. The main reasons are: (1) During loading, unloading, and transportation, the high and low voltage resin coils of the dry-type transformer are displaced. The instantaneous displacement causes great pulling or squeezing forces, resulting in the above problems. (2) This displacement can also easily cause changes in the relative spacing between the high and low voltage resin coils and the core, resulting in a shorter leakage path, which can cause short-circuit discharge between the high and low voltage resin coils and burn out the transformer. (3) This displacement can also easily cause the core to loosen, resulting in insufficient magnetic cross-section, causing vibration, noise, and temperature rise, which in turn damages the insulation and reduces the service life of the transformer. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a dry-type transformer assembly process that can solve the problems of complex assembly processes for general dry-type transformers and the breakage of high-voltage connecting rods and cracking of high-voltage terminals after the dry-type transformer is transported to the site after assembly.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a dry-type transformer assembly process, the innovation of which is as follows: the specific assembly process is as follows:

[0006] S1: Pre-assembly preparation: After the insulation resistance of the stacked and qualified iron core is measured by a dedicated inspector, it is hoisted into the assembly area; the coil that is consistent with the specifications in the drawings and has passed the DC resistance test is hoisted into the assembly area; the insulation components, leads, and transformer accessories are checked to be consistent with the specifications in the drawings.

[0007] S2: Remove the upper yoke: Remove the clamp, clamp insulation plate, and upper yoke of the iron core. When removing, first loosen the pull plate bolts, and then remove the clamping bolts, including the grounding plate; carefully remove the upper yoke and place it flat on the table; use fiberglass tape to tie the lower insulating rubber support rod of the low voltage and the iron core to the iron core.

[0008] S3: Support insulation binding: After binding, ensure that the outermost diameter circle of the rubber rod is concentric with the outer diameter circle of the iron core, and the diameter is 2-4mm in positive tolerance to the inner diameter of the low voltage coil. When fitting, the tightness should meet the assembly requirements.

[0009] S4: Placement of lower pads for coils: Place lower pads around the iron core column on the lower clamp, so that they are adjacent to each other at 90° and at 45° to the center line of the iron core column;

[0010] S5: High-voltage coil hoisting: Use a special hook to hoist the high-voltage coil on both symmetrical sides and secure it with tightening straps; determine the high and low voltage sides of the core and ensure that the high and low voltage coil lead-out positions are consistent with the drawing requirements; roll a piece of thin cardboard into a tapered tube and wrap it around the core column to avoid scratching the coil or damaging the core during coil mounting; place the coil on the corresponding three core columns and let it rest on the lower pad; ensure that the center line of the high-voltage coil lead is aligned with the center line of the pull plate, and adjust the distance between the coil and the core to ensure concentricity;

[0011] S6: Insulating cylinder placement: Place the insulating cylinder as required; adjust the distance between the insulating cylinder and the iron core to ensure concentricity; ensure effective fixing to prevent noise during operation;

[0012] S7: Low-voltage coil hoisting: Use a special hook to hoist the coil through both sides of the high-voltage coil symmetrically and secure it with nuts; the operation method for hoisting the low-voltage coil is the same as that for hoisting the high-voltage coil; after the low-voltage coil is lowered, adjust the distance between the coil and the iron core and ensure concentricity;

[0013] S8: Placement of support pads: Use a force bar to pry the support pads evenly around the circumference between the low-voltage coil and the iron core, and between the high-voltage coil and the low-voltage coil. The number of support pads on the same circumference shall not be less than 4, and the corresponding pads of the inner and outer layers shall be on the same radial line. When placing support pads, it must be ensured that the coil and the iron core are concentric as a whole.

[0014] S9: Assemble the upper yoke: The assembler stands on the high-voltage side and inserts the upper yoke plate; care must be taken to protect the flatness of the yoke plate, and the plate must be inserted in place to ensure the joint requirements are met; the operator must not stand on the clamps; if two people are operating, they should each insert one side facing each other, starting from the main stage; when inserting the upper yoke plate on the low-voltage side, insert the core grounding plate according to the drawing requirements and ensure sufficient effective depth, which is not less than 30mm.

[0015] S10: Install the yoke clamp: Install the clamp and clamp insulation, pull strap and pull strap insulation in sequence; it is a limit combination with the pull plate, and the clamp must be effectively limited by the pull plate; after pre-tightening all fasteners, check the distance between the upper clamp and the low-voltage copper busbar, the shortest straight distance should not be less than 20mm; tighten the upper yoke clamp bolts, pull plate bolts, pull strap bolts and the bolts fixing the insulation terminal to the low-voltage copper busbar in sequence, and ensure that the upper yoke is reliably tightened; after inspection and approval, prepare for painting;

[0016] S11: Apply insulating varnish to the iron core: Apply a layer of insulating varnish evenly to the lower and upper surfaces of the upper yoke, ensuring that the cut surfaces of the yoke pieces are all coated;

[0017] S12: Placement of insulation block on coil: The position of the insulation block on the coil corresponds to the position of the lower insulation block, and the verticality is adjusted with a plumb line.

[0018] S13: Coil clamping: Place the clamping shim on the insulating pad, tighten the coil clamping screw, and clamp the coil so that the compression of the rubber block is not less than 25%; during the clamping process, adjust while clamping to ensure that the coil is upright, the upper end faces of the high and low voltage coils are kept on the same horizontal plane, the three high voltage panels are on the same plane, and the coil phase distance meets the requirements of the drawing.

[0019] S14: Lead wire assembly:

[0020] S14.1: High-voltage lead assembly: Fabricate the copper tubing into high-voltage coil connecting wires according to the drawings and tin-plat them; use heat shrink tubing to cover the connecting wires and heat it with a heat gun until the tubing is tightly fitted onto the connecting wires, ready for use; according to the drawings, cold-press the cable and connector to form high-voltage coil lead wires, use heat shrink tubing to cover the lead wires and heat it with a heat gun until the tubing is tightly fitted onto the lead wires, ready for use; according to the drawings, fix one end of the high-voltage lead wire to the high-voltage coil output terminal and the other end to the clamp with an insulated terminal; connect the corresponding connecting wires according to the connection requirements of the connection group in the drawings; connect the tap terminals with connectors according to the drawings; the tap connection positions are consistent with the drawing requirements;

[0021] S14.2: Low-voltage lead assembly: Fabricate the copper strip into a low-voltage coil connecting bar according to the drawing requirements and tin plate it; connect it to the low-voltage output bar at the position required by the drawing, and fix it to the upper clamp through the insulating terminal;

[0022] S15: Transformer Testing: After the assembly inspection is passed, the transformer is hoisted into the testing area for testing; after the transformer test is passed, it is hoisted back into the assembly area for accessory assembly.

[0023] S16: Assembly of accessories and nameplates: Install the temperature controller, fan, and housing accessories one by one according to the drawings; install the nameplate, and seal the test report, instruction manual, certificate of conformity, and other documents in a bag and attach it to the transformer.

[0024] Furthermore, the placement of the support pad in S8: If a support plate is placed, the support plate is evenly placed at the low-voltage coil copper busbar and around the coil, and it is hammered tightly with an iron hammer. The support plate between the copper busbar and the iron core is required to press tightly against the lower clamp, and the four support plates around it are pressed tightly against the pad.

[0025] Furthermore, in S11, the core insulating varnish is applied with the following requirements: uniform color, no wrinkles, no paint drips, no missing paint, and no bubbles; the grounding plate does not need to be painted, and the connection between it and the clamp should ensure effective contact.

[0026] The advantages of this invention are:

[0027] 1) The assembly process of the dry-type transformer in this invention is simple to operate, the process sequence is reasonably arranged, which facilitates later maintenance, greatly reduces the labor intensity of workers, and avoids the problems of too much welding, painting and other processes during installation, which would cause harm to workers' health and pollute the environment; the assembly method of this dry-type transformer shortens the assembly production cycle, greatly improves production efficiency, and saves labor costs.

[0028] 2) In the assembly process of the dry-type transformer of the present invention, the high and low voltage resin coils have good installation stability and are not easily displaced during transportation, which would cause changes in the relative spacing between the high and low voltage resin coils and the core; by precisely controlling the installation dimensions of each component, the assembly accuracy is guaranteed. Attached Figure Description

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] Figure 1 This is a flowchart of the assembly process of a dry-type transformer according to the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0033] like Figure 1The following describes an assembly process for a dry-type transformer:

[0034] S1: Pre-assembly preparation: After the insulation resistance of the stacked and qualified iron core is measured by a dedicated inspector, it is hoisted into the assembly area; the coil that is consistent with the specifications in the drawings and has passed the DC resistance test is hoisted into the assembly area; the insulation components, leads, and transformer accessories are checked to be consistent with the specifications in the drawings.

[0035] S2: Remove the upper yoke: Remove the clamp, clamp insulation plate, and upper yoke of the iron core. When removing, first loosen the pull plate bolts, and then remove the clamping bolts, including the grounding plate; carefully remove the upper yoke and place it flat on the table; use fiberglass tape to tie the lower insulating rubber support rod of the low voltage and the iron core to the iron core.

[0036] S3: Support insulation binding: After binding, ensure that the outermost diameter circle of the rubber rod is concentric with the outer diameter circle of the iron core, and the diameter is 2-4mm in positive tolerance to the inner diameter of the low voltage coil. When fitting, the tightness should meet the assembly requirements.

[0037] S4: Placement of lower pads for coils: Place lower pads around the iron core column on the lower clamp, so that they are adjacent to each other at 90° and at 45° to the center line of the iron core column;

[0038] S5: High-voltage coil hoisting: Use a special hook to hoist the high-voltage coil on both symmetrical sides and secure it with tightening straps; determine the high and low voltage sides of the core and ensure that the high and low voltage coil lead-out positions are consistent with the drawing requirements; roll a piece of thin cardboard into a tapered tube and wrap it around the core column to avoid scratching the coil or damaging the core during coil mounting; place the coil on the corresponding three core columns and let it rest on the lower pad; ensure that the center line of the high-voltage coil lead is aligned with the center line of the pull plate, and adjust the distance between the coil and the core to ensure concentricity;

[0039] S6: Insulating cylinder placement: Place the insulating cylinder as required; adjust the distance between the insulating cylinder and the iron core to ensure concentricity; ensure effective fixing to prevent noise during operation;

[0040] S7: Low-voltage coil hoisting: Use a special hook to hoist the coil through both sides of the high-voltage coil symmetrically and secure it with nuts; the operation method for hoisting the low-voltage coil is the same as that for hoisting the high-voltage coil; after the low-voltage coil is lowered, adjust the distance between the coil and the iron core and ensure concentricity;

[0041] S8: Placement of support pads: Use a force bar to pry the support pads evenly around the circumference between the low-voltage coil and the iron core, and between the high-voltage coil and the low-voltage coil. The number of support pads on the same circumference shall not be less than 4, and the corresponding pads of the inner and outer layers shall be on the same radial line. When placing support pads, it must be ensured that the coil and the iron core are concentric as a whole.

[0042] S9: Assemble the upper yoke: The assembler stands on the high-voltage side and inserts the upper yoke plate; care must be taken to protect the flatness of the yoke plate, and the plate must be inserted in place to ensure the joint requirements are met; the operator must not stand on the clamps; if two people are operating, they should each insert one side facing each other, starting from the main stage; when inserting the upper yoke plate on the low-voltage side, insert the core grounding plate according to the drawing requirements and ensure sufficient effective depth, which is not less than 30mm.

[0043] S10: Install the yoke clamp: Install the clamp and clamp insulation, pull strap and pull strap insulation in sequence; it is a limit combination with the pull plate, and the clamp must be effectively limited by the pull plate; after pre-tightening all fasteners, check the distance between the upper clamp and the low-voltage copper busbar, the shortest straight distance should not be less than 20mm; tighten the upper yoke clamp bolts, pull plate bolts, pull strap bolts and the bolts fixing the insulation terminal to the low-voltage copper busbar in sequence, and ensure that the upper yoke is reliably tightened; after inspection and approval, prepare for painting;

[0044] S11: Apply insulating varnish to the iron core: Apply a layer of insulating varnish evenly to the lower and upper surfaces of the upper yoke, ensuring that the cut surfaces of the yoke pieces are all coated;

[0045] S12: Placement of insulation block on coil: The position of the insulation block on the coil corresponds to the position of the lower insulation block, and the verticality is adjusted with a plumb line.

[0046] S13: Coil clamping: Place the clamping shim on the insulating pad, tighten the coil clamping screw, and clamp the coil so that the compression of the rubber block is not less than 25%; during the clamping process, adjust while clamping to ensure that the coil is upright, the upper end faces of the high and low voltage coils are kept on the same horizontal plane, the three high voltage panels are on the same plane, and the coil phase distance meets the requirements of the drawing.

[0047] S14: Lead wire assembly:

[0048] S14.1: High-voltage lead assembly: Fabricate the copper tubing into high-voltage coil connecting wires according to the drawings and tin-plat them; use heat shrink tubing to cover the connecting wires and heat it with a heat gun until the tubing is tightly fitted onto the connecting wires, ready for use; according to the drawings, cold-press the cable and connector to form high-voltage coil lead wires, use heat shrink tubing to cover the lead wires and heat it with a heat gun until the tubing is tightly fitted onto the lead wires, ready for use; according to the drawings, fix one end of the high-voltage lead wire to the high-voltage coil output terminal and the other end to the clamp with an insulated terminal; connect the corresponding connecting wires according to the connection requirements of the connection group in the drawings; connect the tap terminals with connectors according to the drawings; the tap connection positions are consistent with the drawing requirements;

[0049] S14.2: Low-voltage lead assembly: Fabricate the copper strip into a low-voltage coil connecting bar according to the drawing requirements and tin plate it; connect it to the low-voltage output bar at the position required by the drawing, and fix it to the upper clamp through the insulating terminal;

[0050] S15: Transformer Testing: After the assembly inspection is passed, the transformer is hoisted into the testing area for testing; after the transformer test is passed, it is hoisted back into the assembly area for accessory assembly.

[0051] S16: Assembly of accessories and nameplates: Install the temperature controller, fan, and housing accessories one by one according to the drawings; install the nameplate, and seal the test report, instruction manual, certificate of conformity, and other documents in a bag and attach it to the transformer.

[0052] Placement of support pads in S8: If support plates are used, place them evenly around the low-voltage coil copper busbar and around the coil, and hammer them tightly. The support plates between the copper busbar and the iron core should be pressed tightly against the lower clamp, and the four support plates around the perimeter should be pressed tightly against the pads.

[0053] S11 core insulation varnish requirements: uniform color, no wrinkles, paint drips, missing paint, or bubbles; grounding plates do not need to be painted, and the connection points with the clamps should ensure effective contact.

[0054] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A dry-type transformer assembly process, characterized by: The specific assembly process is as follows: S1: preparation before assembly: the stacked qualified iron core is hoisted into the assembly area after being measured by the full-time inspection personnel; the coil consistent with the drawing specifications and the direct current resistance inspection qualified is hoisted into the assembly area; the insulation parts, leads and transformer accessories are checked according to the drawing specifications; S2: remove the upper yoke: remove the clamp, clamp insulation board and upper yoke of the iron core; loosen the pull plate bolt first, then remove the clamp bolt, including the grounding sheet; carefully remove the upper yoke and place it on the table surface; use glass fiber tape to bind the low-voltage and the lower part of the rubber support rod on the iron core; S3: support insulation binding: after binding, ensure that the outer diameter circle of the rubber rod is concentric with the outer diameter circle of the iron core, and the diameter is 2-4mm larger than the inner diameter of the low-voltage coil; the tightness of the sleeve meets the assembly requirements; S4: place the lower pad block: place the lower pad block around the iron core column on the lower clamp, so that they are adjacent to each other at 90° and form 45° with the center line of the iron core column; S5: hoist the high-voltage coil: use a special hook to hoist the high-voltage coil on both sides of the symmetry, and use the tightening belt to bind it firmly; determine the high and low voltage side of the iron core to ensure that the outlet position of the high and low voltage coils is consistent with the drawing requirements; use a thin paper board to roll into a tapered paper tube and surround the iron core column to avoid scratching the coil and damaging the iron core sheet during sleeve assembly; sleeve the coil on the corresponding three core columns and drop it on the lower pad block; keep the center line of the high-voltage coil lead consistent with the center line of the pull plate and adjust the distance between the coil and the iron core to ensure concentricity; S6: place the insulation cylinder: place the insulation cylinder according to the requirements; adjust the distance between the insulation cylinder and the iron core to ensure concentricity; ensure effective fixation to prevent noise during operation; S7: hoist the low-voltage coil: use a special hook to hoist the low-voltage coil through the symmetry of the high-voltage coil and fix it with a nut; the operation method of hoisting the low-voltage coil is the same as that of hoisting the high-voltage coil; after placing the low-voltage coil, adjust the distance between the coil and the iron core to ensure concentricity; S8: place the support pad block: evenly use the force rod to pry the support pad block between the low-voltage and the iron core, and between the high-voltage and the low-voltage coil; the number of circumferential pad blocks must not be less than 4, and the corresponding pad blocks in the inner and outer layers must be on the same radial line; when prying the support pad block, the coil and the iron core must be concentric as a whole; S9: assemble the upper yoke: the assembly personnel stand on the high-voltage side and insert the upper yoke sheet; pay attention to protect the flatness of the yoke sheet when inserting the sheet; ensure that the joint meets the requirements; the operator must not stand on the clamp; if two people operate, each inserts one side from the main level; when inserting the upper yoke sheet on the low-voltage side, insert the iron core grounding sheet according to the drawing requirements and ensure sufficient effective depth, which must not be less than 30mm; S10: clamp the upper yoke clamp: clamp the clamp and clamp insulation, pull belt and pull belt insulation in turn; the clamp needs to be effectively limited with the pull plate; all fasteners are pre-tightened first, then check the distance between the upper clamp and the low-voltage copper bar, the shortest straight-line distance must not be less than 20mm; tighten the upper yoke clamp bolt, pull plate bolt, pull belt bolt and low-voltage copper bar fixed insulation terminal bolt in turn and ensure the reliable fastening of the upper yoke; after inspection, prepare for painting; S11: Brush iron core insulating paint: the upper yoke lower surface and the upper surface of the secondary uniform brush a layer of insulating paint, ensure that the yoke cut surface are brushed to; S12: Coil on the insulating block placement: coil on the insulating pad placement position corresponding to the lower insulating pad position, up and down vertical degree with plumb line adjustment; S13: Coil compression: insulating pad on the put on compression gasket, screw on the coil compression screw, compression coil, the compression amount of rubber block should not be less than 25%; compression process, edge compression adjustment to ensure that the coil is straight, high and low pressure coil end surface to keep in the same horizontal plane, three high voltage panel in a plane, coil distance between the corresponding figure requirements; S14: lead assembly: S14.1: high voltage lead assembly: according to the drawing requirements, the copper pipe is made into high voltage coil connecting line, and is tinned; with heat shrink tube on the connecting line, with hot blow gun to heat to the sleeve tightly on the connecting line, ready for use; according to the drawing requirements, the cable and the terminal are cold pressed to make high voltage coil lead-out line, and the heat shrink tube is sleeved on the lead-out line, and the heat blow gun is used to heat to the sleeve tightly on the lead-out line, ready for use; according to the drawing requirements, one end of the high voltage lead is fixed on the high voltage coil lead-out terminal, and the other end is fixed on the clamp by the insulating terminal; according to the connection requirements of the drawing, the corresponding connection lines are connected; according to the drawing requirements, the connection piece is connected to the tapping terminal; the tapping connection position is consistent with the drawing requirements; S14.2: low voltage lead assembly: according to the drawing requirements, the copper strip is made into low voltage coil connecting row, and is tinned; according to the drawing requirements, the position is connected with the low voltage lead-out row, and is fixed on the upper clamp through the insulating terminal; S15: transformer test: after the assembly inspection is qualified, it is hoisted into the test area, and the transformer test is carried out; after the transformer test is qualified, it is hoisted into the assembly area again; accessory assembly is carried out; S16: accessory and nameplate assembly: temperature controller, fan, shell accessories are installed one by one according to the drawing; install the nameplate, and seal the test report, instruction manual, certificate and other documents in the bag, and attach them to the transformer.

2. A dry-type transformer assembly process as claimed in claim 1, wherein: The placement of the support pad in S8: if the support plate is placed, the support plate is placed uniformly at the low voltage coil copper row and around the coil, and is hammered tightly with a hammer, and the support plate between the copper row and the iron core is required to be tightly contacted with the lower clamp, and the four surrounding support plates are tightly contacted with the pad.

3. A dry-type transformer assembly process as claimed in claim 1, wherein: The brush iron core insulating paint in S11: requirements: uniform color, no wrinkles, hanging paint, lack of paint and bubble phenomenon; the grounding piece does not need to be painted, and the connection part with the clamp ensures effective contact.

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