Stator annular lead fixing structure and method for large generator

Abstract

The present disclosure relates to the field of generator manufacturing, and disclosed are a stator annular lead fixing structure and method for a large generator. The structure comprises a conical ring, stator annular leads, insulating pressing plates, and a hooping device; the outer circle surface of the conical ring is provided with arc-shaped grooves used for embedding the stator annular leads; the insulating pressing plates are pressed on the outer surfaces of the stator annular leads protruding out of the arc-shaped grooves; the hooping device comprises tightening strips and a tightener; the tightening strips are tied on the outer sides of the insulating pressing plates, and are tightened by means of the tightener to fix the stator annular leads. The method comprises: placing in a large conical ring groove a shape-adaptive material which is thick enough, impregnating the shape-adaptive material in medium-temperature curing epoxy glue, then mounting all annular leads in the large conical ring groove, and screwing steel tool screws into two ends of each of insulating pressing plates and tool holes of a large conical ring to temporarily fix the annular leads and the insulating pressing plates; and mounting a hooping device. The lead fixing structure of the present invention has large overall rigidity, high strength and good insulating properties, and effectively improves the reliability of fixing of annular leads.

Description

A large generator stator ring lead fixing structure and fixing method Technical Field

[0001] The present invention relates to the field of steam turbine generator design and manufacturing, and in particular to a large-scale generator stator annular lead fixing structure and a fixing method. Background Art

[0002] Generator ring leads are hollow, conductive round or square copper tubes. They are a crucial component for transmitting electrical energy. One end is connected to the high-voltage stator coil, and the other end is connected to other conductive components, serving as a connection between water and electrical circuits. Typically, large-capacity generator ring lead copper tubes are exposed to hydrogen pressure on the outside and water pressure on the inside.

[0003] During operation, the generator's ring leads carry an AC current of approximately 10,000A. This enormous current, coupled with the small distance between the leads (typically only 90mm between centerlines), can generate significant and harmful alternating electromotive force, necessitating effective securing. If the ring leads are not effectively secured, the fixings can loosen and wear during generator operation, damaging the ring lead's main insulation and even wearing down the ring lead's copper tube, leading to water leaks, electrical grounding, and other downtimes, resulting in significant economic losses.

[0004] In the prior art, the more typical ones are the binding type annular lead fixing structure and the cone ring pressure plate insulated screw tensioning type annular lead fixing structure, as shown in Figure 3 of the specification. The generator binding type annular lead fixing structure adopts an epoxy glass cloth laminate bracket and a binding rope to form a fixing structure. The stator annular lead is supported by a bracket and an insulating bracket, and the lead is tightly packed with a pad wrapped with impregnated felt, and fixed with a binding rope to ensure that the annular lead and the pad do not loosen or shift, so that the entire end becomes a solid whole. The rope used for binding is an alkali-free glass wire rope, an alkali-free glass filament bundle, a glass fiber roving or a weft-free tape, etc., and the glue is a medium-temperature curing epoxy adhesive and a two-component epoxy resin room-temperature curing adhesive. The advantage of the binding type annular lead fixing structure is that the structure is simple and the operation and preparation are convenient, but the disadvantage is that the overall stiffness of the generator end is poor. When the unit capacity is too large, the electric force of the annular lead will increase significantly, and the strength of the binding structure cannot meet the design.

[0005] The cone-ring, pressure plate, and insulated screw tensioning ring lead fixing structure uses a large, integral cone ring at the end of the stator winding. The ring lead is placed in a groove in the cone ring and secured by an insulating screw and pressure plate, as shown in Figure 4 of the specification. The advantages of this cone-ring, pressure plate, and insulated screw tensioning ring lead fixing structure include high overall rigidity, high strength, excellent insulation performance, high frequency response, high reliability, and long life, meeting the power requirements of large-capacity generators. However, the disadvantages of this fixing method are the large number of screws required for installation, complex operation, and difficult quality control. It is also difficult to prevent loosening of bolts or pressure plates during operation.

[0006] Therefore, it is urgent to design a large-scale generator stator ring lead fixing structure with high reliability.

[0007] Summary of the Invention

[0008] The present invention aims to solve the shortcomings of the existing generator ring lead fixing structure and proposes a large generator stator ring lead fixing structure and fixing method. A clamping device is used to clamp the pressure plate and the ring lead to the outer surface of the large cone ring at the generator excitation end. It has the advantages of high fixing reliability and simple installation.

[0009] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0010] A large generator stator ring lead fixing structure is characterized by including a conical ring, a stator ring lead, an insulating pressure plate and a tightening device; the outer circular surface of the conical ring is provided with an arc groove for embedding the stator ring lead, the insulating pressure plate is pressed on the outer surface of the stator ring lead protruding from the arc groove, and the tightening device includes a tightening strip and a tightener, the tightening strip is bundled on the outside of the insulating pressure plate, and is tightened by the tightener to fix the stator ring lead.

[0011] Furthermore, a plurality of arc-shaped grooves are provided, and these arc-shaped grooves are parallel to each other and distributed at equal intervals on the surface of the cone ring, and the stator annular lead wires are embedded in each arc-shaped groove one by one.

[0012] Furthermore, a conformable material for adjusting thickness is provided in the arc-shaped groove.

[0013] Furthermore, a plurality of insulating pressing plates are provided, and these insulating pressing plates are arranged at equal intervals in the circumferential direction of the cone ring along a direction perpendicular to the arc-shaped slot and the stator annular lead.

[0014] Furthermore, the insulating pressing plate adopts F-grade epoxy glass mat laminate CC132 with a tensile strength of ≥250MPa.

[0015] Furthermore, a plurality of positioning grooves are provided on the surface of the insulating pressing plate in contact with the stator annular lead wires, and these positioning grooves match the shapes and sizes of the plurality of stator annular lead wires protruding from the arc-shaped grooves.

[0016] Furthermore, tool holes are provided at both ends of the insulating pressing plate, and threaded holes for installing tool bolts are provided on both sides of the large cone ring.

[0017] Furthermore, several groups of tightening devices are provided, and these groups of tightening devices are arranged at intervals on the outer surface of the insulating pressure plate. The upper surface of the insulating pressure plate is provided with slots corresponding to the layout positions of the tightening strips.

[0018] Furthermore, the tightening strip is woven from a whole length of high-strength material; the tightener is arranged at the joint where the ends of the tightening strip are connected around a circle.

[0019] The present invention also provides a method for fixing a large generator stator ring lead, comprising the following steps:

[0020] 1) Prepare a large conical ring; pre-design and process an arc groove for installing the ring lead on the circumferential surface of the large conical ring, and process a tool screw hole for temporarily fixing the ring lead in conjunction with the insulating pressure plate;

[0021] 2) Prepare the ring lead;

[0022] 3) Prepare an insulating plate; machine a positioning groove on the lower surface of the insulating plate at a position corresponding to the arc groove, wherein the depth and width of the positioning groove match the shape of the annular lead protruding from the arc groove; machine a clamping groove on the upper surface of the insulating plate to match the tightening strip in the clamping device, and apply lubricant to the clamping groove; machine tool holes at both ends of the insulating plate for temporary fixing;

[0023] 4) Install the large conical ring at the end of the generator stator. Place a sufficiently thick conformable material in the groove of the large conical ring. Impregnate the conformable material with medium-temperature curing epoxy adhesive. Then install all the ring leads in the groove of the large conical ring. Use steel tool bolts to screw into the ends of the insulating pressure plate and the tool holes of the large conical ring to temporarily fix the ring leads and the insulating pressure plate.

[0024] 5) Install the tightening device, apply lubricant to the inner surface of the tightening strip, circle around the outside of the insulating plate, converge in the operable space, and tighten; according to the curing time characteristics of the glue, tighten multiple times until the glue is completely cured;

[0025] 6) After tightening, remove the tool bolts and the installation is complete.

[0026] In summary, the present invention has the following advantages:

[0027] 1. The present invention changes the existing annular lead fixing method and adopts a clamping device to clamp the pressure plate and the annular lead to the outer surface of the large cone ring at the generator excitation end. By adjusting the tightening method, the fixing structure is connected as a whole, which effectively improves the reliability of the annular lead fixing;

[0028] 2. The lead fixing structure of the present invention has high overall rigidity, high strength and good insulation performance. The insulating pressure plate adopts F-class epoxy glass mat laminate, which has high strength characteristics. The tightening strip is woven from a full length of high-strength material, which can meet the strength requirements under the operating conditions of the generator;

[0029] 3. The present invention can adjust the tightening force of the clamping device multiple times to avoid loosening of the fixed structure. It requires a small operating space, has simple process operation, strong controllability, can be stopped for replacement, and can also be used to carry out technical transformation of the running generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic diagram of the overall structure of the present invention;

[0031] FIG2 is an enlarged schematic diagram of the structure of FIG1;

[0032] FIG3 is a conventional binding type ring lead fixing structure;

[0033] FIG4 is a conventional cone ring pressure plate insulation screw tensioning type annular lead fixing structure;

[0034] In the figure,

[0035] 1. Stator ring lead, 2. Cone ring, 3. Insulation pressure plate, 4. Tightening strip, 5. Tightener. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0039] In the description of the present invention, it should be noted that the terms "upper," "vertical," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is typically placed when in use, or are commonly understood by those skilled in the art. These terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0041] Example 1

[0042] The present invention provides a large generator stator ring lead fixing structure, as shown in Figures 1-2, comprising a cone ring 2 and a stator ring lead 1 arranged on the cone ring 2, an insulating pressure plate 3 and a clamping device.

[0043] The outer surface of the cone ring 2 is provided with several arcuate grooves for accommodating the stator ring lead wires 1. These arcuate grooves are parallel to each other and evenly spaced across the cone ring 2. Conformable material is placed within these arcuate grooves to adjust their thickness. The stator ring lead wires 1 are inserted into each arcuate groove one by one to achieve initial positioning.

[0044] The stator ring lead 1 in this embodiment is formed by bending a hollow copper tube, the interior of which can be cooled by water, and the exterior of which is a 3-10 mm thick main insulation. The stator ring lead 1 can also be formed by bending a square tube or other shaped copper tube.

[0045] The insulating pressure plate 3 covers the surface of the stator ring lead 1 and is arranged perpendicular to the arc-shaped slot and the stator ring lead 1. In this embodiment, several insulating pressure plates 3 are provided and evenly spaced along the circumference of the cone ring 2. The insulating pressure plates 3 have high strength. In this embodiment, the insulating pressure plates 3 are made of F-grade epoxy glass mat laminate CC132 with a tensile strength of ≥250 MPa.

[0046] A plurality of positioning grooves are provided on the surface of the insulating pressing plate 3 that contacts the stator ring lead 1 . These positioning grooves match the shape and size of the stator ring lead 1 protruding from the arc-shaped groove.

[0047] Furthermore, tool holes are provided at both ends of the insulating pressure plate 3, which are used to cooperate with tool bolts to temporarily fix the ring lead and the insulating pressure plate 3. Correspondingly, threaded holes are provided on both sides of the large cone ring 2 for cooperating with the insulating pressure plate 3 to install tool bolts.

[0048] The tightening devices are bundled and mounted on the surface of the insulating platen 3. Several sets of tightening devices are provided, evenly spaced on the outer surface of the insulating platen 3, securing the insulating platen 3 and the stator ring lead 1. In this embodiment, each set of tightening devices includes a tightening strip 4 and a tightener 5. The ends of the tightening strip 4 are wrapped around a circle and then secured with the tightener 5. The tightener 5 can perform multiple tightening operations depending on the stress release state. In this embodiment, the tightening strip 4 is woven from a single length of high-strength material, such as carbon fiber.

[0049] In order to prevent the tightening strips 4 from axially slipping when tightening, the upper surface of the insulating pressure plate 3 is provided with grooves corresponding to the layout positions of each tightening strip 4. Lubricant can be applied to the grooves to reduce friction between the tightening strips 4.

[0050] The lead fixing structure of the present invention has high overall rigidity, high strength, and good insulation performance. The tightening force can be adjusted multiple times, the required operating space is small, the process operation is simple, the controllability is strong, the machine can be stopped for replacement, and the operating generator can also be technically modified.

[0051] Example 2

[0052] This embodiment provides a method for fixing a large generator stator ring lead, comprising the following steps:

[0053] 1) Prepare the large conical ring 2; pre-design and process the arc groove for installing the ring lead on the circumferential surface of the large conical ring 2, and process the tool screw hole for temporarily fixing the ring lead with the insulating pressure plate 3;

[0054] 2) Prepare the ring lead;

[0055] 3) Prepare the insulating plate 3; machine a positioning groove on the lower surface of the insulating plate 3 at a position corresponding to the arc groove, wherein the depth and width of the positioning groove match the shape of the annular lead protruding from the arc groove; machine a clamping groove on the upper surface of the insulating plate 3 to match the tightening strip 4 in the tightening device, and apply lubricant to the clamping groove; machine tool holes at both ends of the insulating plate 3 for temporary fixing;

[0056] 4) Install the large conical ring 2 at the end of the generator stator. Place a sufficiently thick conformable material in the groove of the large conical ring 2. The conformable material is impregnated with medium-temperature curing epoxy adhesive. Then install all the ring leads in the groove of the large conical ring 2. Use steel tool bolts to screw into the ends of the insulating pressure plate 3 and the tool holes of the large conical ring 2 to temporarily fix the ring leads and the insulating pressure plate 3.

[0057] In this embodiment, the thickness of the conformable material is twice the gap to be filled, and the gap is filled after compression and curing, and the gap range is 2-10 mm.

[0058] 5) Install the tightening device, apply lubricant to the inner surface of the tightening strip 4, wrap it around the outer side of the insulating pressure plate 3 in a circle, and then converge and tighten it in the operable space; according to the curing time characteristics of the glue, tighten it multiple times until the glue is completely cured;

[0059] 6) After tightening, remove the tool bolts and the installation is complete.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A large generator stator annular lead fixing structure, characterized in that: The invention comprises a cone ring (2), a stator ring lead (1), an insulating pressure plate (3) and a clamping device; the outer circumferential surface of the cone ring (2) is provided with an arc groove for embedding the stator ring lead (1); the insulating pressure plate (3) is pressed on the outer surface of the stator ring lead (1) protruding from the arc groove; the clamping device comprises a tightening strip (4) and a tightener (5); the tightening strip (4) is bundled on the outer side of the insulating pressure plate (3) and is tightened by the tightener (5) to fix the stator ring lead (1).

2. A large generator stator annular lead fixing structure according to claim 1, characterized in that: A plurality of arc-shaped grooves are provided, and the plurality of arc-shaped grooves are parallel to each other and are distributed at equal intervals on the surface of the cone ring (2), and the stator annular lead wires (1) are embedded in each arc-shaped groove one by one.

3. A large generator stator annular lead fixing structure according to claim 1, characterized in that: The arc-shaped groove is provided with a conformable material for adjusting thickness.

4. A large generator stator annular lead fixing structure according to claim 2, characterized in that: A plurality of insulating pressing plates (3) are provided, and the plurality of insulating pressing plates (3) are arranged at equal intervals in the circumferential direction of the cone ring (2) along a direction perpendicular to the arc-shaped slot and the stator annular lead wire (1).

5. A large generator stator annular lead fixing structure according to claim 4, characterized in that: The insulating pressing plate (3) is made of F-grade epoxy glass felt laminate CC132, and its tensile strength is ≥250MPa.

6. A large generator stator annular lead fixing structure according to claim 1, characterized in that: A plurality of positioning grooves are arranged on the surface of the insulating pressing plate (3) in contact with the stator annular lead wire (1), and the positioning grooves match the shapes and sizes of the plurality of stator annular lead wires (1) protruding from the arc-shaped grooves.

7. A large generator stator annular lead fixing structure according to claim 1, characterized in that: Tool holes are arranged at both ends of the insulating pressing plate (3), and threaded holes for installing tool bolts are arranged on both sides of the large cone ring (2).

8. A large generator stator annular lead fixing structure according to claim 1, characterized in that: A plurality of groups of tightening devices are provided, and the plurality of groups of tightening devices are arranged at intervals on the outer surface of the insulating pressing plate (3), and the upper surface of the insulating pressing plate (3) is provided with slots corresponding to the arrangement positions of the tightening strips (4).

9. A large generator stator annular lead fixing structure according to claim 1, characterized in that: The tightening strip (4) is woven from a whole length of high-strength material; the tightener (5) is arranged at the joints of the two ends of the tightening strip (4) after they have circled a circle.

10. A method for fixing a large generator stator ring lead, characterized in that: The steps include: 1) preparing a large conical ring (2); pre-designing and processing an arc groove for installing the annular lead on the circumferential surface of the large conical ring (2), and processing a tool screw hole for cooperating with the insulating pressing plate (3) to temporarily fix the annular lead; 2) Prepare the ring lead; 3) preparing an insulating pressing plate (3); processing a positioning groove at a position corresponding to the arc groove on the lower surface of the insulating pressing plate (3), wherein the depth and width of the positioning groove match the shape of the annular lead protruding outside the arc groove; processing a clamping groove matching the tightening strip (4) in the clamping device on the upper surface of the insulating pressing plate (3), and applying lubricant in the clamping groove; processing tool holes for temporary fixing at both ends of the insulating pressing plate (3); 4) Install the large cone ring (2) at the end of the generator stator, place a sufficiently thick conformable material in the groove of the large cone ring (2), impregnate the conformable material with medium-temperature curing epoxy glue, then install all the annular leads in the groove of the large cone ring (2), and use steel tool bolts to screw into the two ends of the insulating pressure plate (3) and the tool holes of the large cone ring (2) to temporarily fix the annular leads and the insulating pressure plate (3); 5) Install the tightening device, apply lubricant to the inner surface of the tightening strip (4), wrap a circle around the outer side of the insulating pressing plate (3), converge in the operable space and tighten; according to the curing time characteristics of the glue, tighten several times until the glue is completely cured; 6) After tightening, remove the tool bolts and the installation is complete.

Images