WO2025092714A1 - Stator annular lead fixing structure and method for large generator - Google Patents

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

The 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

The generator ring lead is a hollow conductive round copper tube or square copper tube. It is one of the important components for the transmission of power in the generator. One end of it is connected to the high-potential stator coil, and the other end is connected to other conductive components. It has the function of connecting the waterway and the circuit. Usually, the outside of the large-capacity generator ring lead copper tube is a hydrogen pressure environment, and the inside is a water pressure environment.

During the operation of the generator ring lead, the AC current passing through is about 10000A. Such a huge current, with a small distance between each other, generally the center line spacing is only 90mm, will form a huge and harmful alternating electric force, so it needs to be effectively fixed. Once the ring lead is not effectively fixed, when the generator is running, the fixing structure will loosen and wear, destroying the main insulation of the ring lead, and even wearing the ring lead copper tube, causing water leakage, electrical grounding and other shutdown accidents, causing huge economic losses.

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 a rubber-impregnated felt, and is fixed with a binding rope to ensure that the annular lead and the pad do not loosen or move, 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 glue. The advantages of the binding type annular lead fixing structure are simple structure and convenient operation and preparation, 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.

The cone ring pressure plate insulated screw tensioning type annular lead fixing structure refers to the use of an integral large cone ring at the end of the stator winding, the annular lead is placed in the groove of the cone ring, and the annular lead is fixed by the insulating screw and the pressure plate, as shown in Figure 4 of the specification. The advantages of the cone ring pressure plate insulated screw tensioning type annular lead fixing structure are high overall rigidity, high strength, good insulation performance, high frequency response, high reliability, and long life, which meet the requirements of large-capacity generator operation electric power. The disadvantages of this fixing method are that the number of installation screws is large, the operation is complicated, the quality control is difficult, and it is difficult to avoid the loosening of bolts or pressure plates during operation.

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

Summary of the invention

The present invention aims to solve the shortcomings of the existing generator annular lead fixing structure and proposes a large generator The motor stator annular lead fixing structure and fixing method adopt 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, which has the advantages of high fixing reliability and simple installation.

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

A large generator stator ring lead fixing structure, characterized in that it includes 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, the tightening device includes a tightening strip and a tightener, the tightening strip is bundled on the outside of the insulating pressure plate, and the stator ring lead is fixed by tightening it through the tightener.

Furthermore, a plurality of arc-shaped grooves are provided, and the plurality of arc-shaped grooves are parallel to each other and are evenly spaced on the surface of the cone ring, and the stator annular lead wires are embedded in each arc-shaped groove one by one.

Furthermore, a conformable material for adjusting thickness is provided in the arc groove.

Furthermore, a plurality of insulating pressing plates are provided, and the plurality of 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 wire.

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

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

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.

Furthermore, 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, and the upper surface of the insulating pressing plate is provided with slots corresponding to the layout positions of the tightening strips.

Furthermore, the tightening strip is woven from a whole length of high-strength material; the tightener is arranged at the joints where the ends of the two ends of the tightening strip are wrapped around a circle.

The present invention also provides a method for fixing a large generator stator annular lead wire, comprising the following steps:

1) Prepare a large cone ring; pre-design and process an arc groove for installing the ring lead on the circumferential surface of the large cone ring, and process a tool screw hole for temporarily fixing the ring lead in cooperation with the insulating pressing plate;

2) Prepare the ring lead;

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

4) Install the large cone ring at the end of the generator stator, place a sufficiently thick conformable material in the groove of the large cone ring, and immerse the conformable material in the groove. Temperature-cured epoxy glue is used to temporarily fix the ring leads and the insulating plate by screwing steel tool bolts into the tool holes at both ends of the insulating plate and the large cone ring.

5) Install the tightening device, apply lubricant to the inner surface of the tightening strip, make a circle along the outer side of the insulating pressing plate, 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.

In summary, the present invention has the following advantages:

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

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

3. The present invention can adjust the tightening force of the clamping device multiple times to avoid loosening of the fixed structure. The required operating space is small, the process operation is simple, the controllability is strong, the machine can be stopped for replacement, and the running generator can also be technically modified.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG2 is an enlarged schematic diagram of the structure of FIG1;

FIG3 is an existing binding type annular lead fixing structure;

FIG4 is an existing cone ring pressure plate insulation screw tensioning type annular lead fixing structure;

In the figure,

1. Stator ring lead, 2. Cone ring, 3. Insulation pressure plate, 4. Tightening strip, 5. Tightener.

DETAILED DESCRIPTION

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 here can be arranged and designed in various different configurations.

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 claimed for protection, but merely represents selected embodiments of the present invention. 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.

It should be noted that similar reference numerals and letters refer to similar items in the following drawings, and therefore, whenever an item is referred to in a If a feature is defined in one figure, it does not need to be further defined or explained in the subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "vertical", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Example 1

The present invention provides a large generator stator annular lead fixing structure, as shown in FIG1-2, comprising a cone ring 2 and a stator annular lead 1 arranged on the cone ring 2, an insulating pressing plate 3 and a clamping device.

The outer surface of the cone ring 2 is provided with a plurality of arc grooves for embedding the stator annular lead wires 1. The arc grooves are parallel to each other and are evenly spaced on the surface of the cone ring 2. Conformable materials for adjusting thickness are provided in the arc grooves, and the stator annular lead wires 1 are embedded in each arc groove one by one to achieve preliminary positioning.

The stator annular lead wire 1 in this embodiment is formed by bending a hollow copper tube, the inside of which can be cooled by water, and the outside of which is a main insulation with a thickness of 3 to 10 mm. The stator annular lead wire 1 can also be formed by bending a square tube or a copper tube of other shapes.

The insulating pressing plate 3 covers the surface of the stator ring lead 1 and is arranged in a direction perpendicular to the arc slot and the stator ring lead 1. In this embodiment, a plurality of insulating pressing plates 3 are provided and are evenly arranged at equal intervals along the circumference of the cone ring 2. The insulating pressing plate 3 has a high strength characteristic. In this embodiment, the insulating pressing plate 3 adopts F-grade epoxy glass felt laminate CC132 with a tensile strength of ≥250MPa.

A plurality of positioning grooves are arranged on the surface of the insulating pressing plate 3 that contacts the stator ring lead 1 , and these positioning grooves match the shape and size of the stator ring lead 1 protruding from the arc groove.

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 annular 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.

The clamping device is bundled and arranged on the surface of the insulating pressing plate 3, and the clamping device is provided with several groups, and these several groups of clamping devices are arranged on the surface of the insulating pressing plate 3. The insulating plate 3 and the stator ring lead 1 are evenly arranged at intervals on the outer surface of the insulating plate 3 to fix the insulating plate 3 and the stator ring lead 1. In this embodiment, each set of tightening devices includes a tightening strip 4 and a tightener 5, wherein the ends of the tightening strip 4 are fixed by the tightener 5 after winding a circle, and the tightener can perform multiple tightening operations according to the stress release state. In this embodiment, the tightening strip 4 is woven from a whole length of high-strength material, such as a carbon fiber material.

In order to prevent the tightening strips 4 from axially sliding when tightening, the upper surface of the insulating pressing plate 3 is provided with grooves corresponding to the layout positions of the tightening strips 4, and lubricant can be applied in the grooves to reduce the friction between the tightening strips 4.

The lead fixing structure of the present invention has large overall rigidity, high strength, good insulation performance, can adjust the tightening force multiple times, requires a small operating space, has simple process operation, strong controllability, can be stopped for replacement, and can also carry out technical transformation of the running generator.

Example 2

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

1) Prepare a large cone ring 2; pre-design and process an arc groove for installing the ring lead on the circumferential surface of the large cone ring 2, and process a tool screw hole for temporarily fixing the ring lead in cooperation with the insulating pressing plate 3;

2) Prepare the ring lead;

3) Prepare the insulating pressing plate 3; Process 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 from the arc groove; Process a card groove matching the tightening strip 4 in the clamping device on the upper surface of the insulating pressing plate 3, and apply lubricant in the card groove; Process 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;

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.

5) Install the tightening device, apply lubricant to the inner surface of the tightening strip 4, make a circle along the outer side of the insulating pressing plate 3, and then converge and tighten in the operable space; 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.

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 protection scope of the present invention.

Claims (10)

A large generator stator ring lead fixing structure, characterized in that it 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). According to a large generator stator annular lead fixing structure as described in claim 1, it is characterized in that a plurality of arc grooves are provided, the plurality of arc grooves are parallel to each other and are evenly spaced on the surface of the cone ring (2), and the stator annular lead (1) is embedded in each arc groove one by one. According to the large generator stator annular lead fixing structure according to claim 1, it is characterized in that a conformable material for adjusting thickness is provided in the arc groove. According to a large generator stator ring lead fixing structure as described in claim 2, it is characterized in that a plurality of insulating pressure plates (3) are provided, and the plurality of insulating pressure plates (3) are arranged at equal intervals in the circumferential direction of the cone ring (2) along a direction perpendicular to the arc slot and the stator ring lead (1). According to the large generator stator annular lead fixing structure described in claim 4, it is characterized in that the insulating pressure plate (3) adopts F-grade epoxy glass felt laminate CC132, and its tensile strength is ≥250MPa. According to a large generator stator ring lead fixing structure as described in claim 1, it is characterized in that a plurality of positioning grooves are provided on the surface of the insulating pressure plate (3) in contact with the stator ring lead (1), and these positioning grooves match the shape and size of the plurality of stator ring leads (1) protruding from the arc groove. According to the large generator stator annular lead fixing structure as described in claim 1, it is characterized in that tool holes are provided at both ends of the insulating pressure plate (3), and threaded holes for installing tool bolts are provided on both sides of the large cone ring (2). According to a large generator stator annular lead fixing structure as described in claim 1, it is characterized in that a plurality of groups of clamping devices are provided, and the plurality of groups of clamping devices are arranged at intervals on the outer surface of the insulating pressure plate (3), and the upper surface of the insulating pressure plate (3) is provided with a card slot corresponding to the layout position of each tightening strip (4). According to the large generator stator annular lead fixing structure as described in claim 1, it is characterized in that the tightening strip (4) is woven from a whole length of high-strength material; and the tightener (5) is arranged at the joint after the ends of the tightening strip (4) are wrapped around a circle. A method for fixing a large generator stator ring lead, characterized in that it comprises the following steps: 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.