阅读说明：本技术 一种层错防晕结构的定子线棒制作方法 (Manufacturing method of stator bar with staggered corona-proof structure ) 是由 孙永鑫 李屹 梁彬 程宇坤 杨秀伟 曹宏玉 王启发 云浩 于 2021-10-14 设计创作，主要内容包括：本发明公开一种层错防晕结构的定子线棒制作方法。定子线棒的防晕结构由多层防晕材料和层间多胶粉云母材料所组成的层错复合结构。层错防晕结构的定子线棒具有防晕结构简单,工艺方便,易于设计和制造的优点。在不同防晕材料层间添加多胶粉云母材料,能够在提高线棒介电性能的情况下,保护多层防晕搭接位置,加强防晕层的粘接性能,避免定子线棒防晕起层、防晕搭接处阻值不可控情况,保障定子线棒防晕性能的稳定性。(The invention discloses a method for manufacturing a stator bar with a staggered corona-proof structure. The anti-corona structure of the stator bar is a laminated composite structure consisting of multiple layers of anti-corona materials and interlayer multi-rubber powder mica materials. The stator bar with the fault corona prevention structure has the advantages of simple corona prevention structure, convenient process and easy design and manufacture. The multi-rubber powder mica material is added between different anti-corona material layers, so that the multilayer anti-corona lap joint positions can be protected under the condition of improving the dielectric property of the coil bar, the bonding property of the anti-corona layers is enhanced, the uncontrollable conditions of the anti-corona layers and the resistance values of the anti-corona lap joints of the stator coil bar are avoided, and the stability of the anti-corona property of the stator coil bar is ensured.)

1. A manufacturing method of a stator bar with a staggered corona-proof structure is characterized by comprising the following steps:

the method comprises the following steps: the high-resistance corona-proof structure of the stator bar consists of an epoxy multi-glue powder mica tape (1), a silicon carbide middle-resistance corona-proof tape (2) and a silicon carbide high-resistance corona-proof tape (3)The epoxy multi-glue powder mica tape (1) has the thickness of 0.14mm, the glue content of 37-40 percent and the volume resistivity>10¹²Omega.m, the thickness of the silicon carbide middle-resistance anti-corona band (2) is 0.12mm, and the inherent surface resistivity is 10¹¹～10¹²Omega, nonlinear coefficient of 0.5-1.0 cm/kV, thickness of silicon carbide high-resistance anti-corona band (3) of 0.12mm, and inherent resistivity of 10¹²～10¹³Omega, the nonlinear coefficient is 3-5 cm/kV;

step two: the formed wire (4) is wrapped by a thickness d₀The main insulating material (5) is wrapped with a layer of low-resistance corona-proof material (6) in a half-lap winding way in the main insulating groove part and is wrapped to a middle-low resistance lap joint part (7);

step three: a layer of epoxy multi-glue mica tape (1) is wrapped on the low-resistance corona-proof material (6) in a half-lap winding way, and the axial distance d of the low-resistance corona-proof material (6) is covered on one side₁4cm, the other side is covered with a main insulating material (5) for an axial distance d₁；

Step four: a layer of silicon carbide middle anti-corona belt (2) is wrapped above the low-resistance anti-corona material (6) and the epoxy multi-gelatine powder mica tape (1) on the low-resistance anti-corona material in a half-lap winding way, and the epoxy multi-gelatine powder mica tape (1) is covered by the silicon carbide middle anti-corona belt (2) at an axial distance d₂＝2cm；

Step five: wrapping a layer of epoxy multi-glue mica tape (1) on the silicon carbide middle-resistance anti-corona tape (2) in a semi-lap winding way, and covering the silicon carbide middle-resistance anti-corona tape (2) at one side by the axial distance d₁4cm, the other side is covered with a main insulating material (5) for an axial distance d₁；

Step six: a layer of silicon carbide high-resistance anti-corona belt (3) is wrapped above the silicon carbide middle-resistance anti-corona belt (2) and the epoxy rich-gelatine powder mica tape (1) on the silicon carbide middle-resistance anti-corona belt in a semi-lap winding way, and the axial distance d of the epoxy rich-gelatine powder mica tape (1) is covered₂＝2cm；

Step seven: after the lamination of the anti-corona layer with the staggered structure is finished, the forming lead (4) is heated, pressurized, cured and formed, and then the die is removed.

2. The method for manufacturing a stator bar with a staggered corona-proof structure as claimed in claim 1, wherein: and seventhly, curing and molding the molded lead (4) in an internal heating mode.

3. The method for manufacturing a stator bar with a staggered corona-proof structure as claimed in claim 1, wherein: in the seventh step, the temperature rising speed of the formed lead is 1.5 ℃/min.

4. The method for manufacturing a stator bar with a staggered corona-proof structure as claimed in claim 1, wherein: and seventhly, unloading the mold when the mold is naturally cooled to below 50 ℃.

Technical Field

The invention relates to the field of generator stator bar, in particular to a manufacturing method of a stator bar with a staggered corona-proof structure.

Background

The anti-corona structure is one of the most important insulation structures of the stator bar of the generator, and the quality of the anti-corona performance has a decisive effect on the stable operation of the stator winding. The corona-proof material at the end part of the stator bar is usually a multilayer non-linear silicon carbide corona-proof material, the resistivity of the material is reversely changed with the electric field intensity, so that the electric field intensity at the end part of the bar can be gentle, and the highest electric field intensity at the end part can be effectively reduced.

The anti-corona structure generally adopts a multilayer anti-corona structure which is wrapped with different nonlinear silicon carbide anti-corona materials in sequence, and the different anti-corona materials are in direct contact at the lap joint. The traditional view points that different corona-proof materials are in direct contact with each other can ensure effective connection between the different corona-proof materials, so that the continuity of the potential distribution of the end part of the winding bar is better.

However, the direct contact of the different antihalation materials causes interpenetration during the curing of the materials, causing an uncontrolled variation of the resistance of the antihalation material and affecting the electric field distribution. Meanwhile, because the adhesion performance of the corona-proof material is poor, the traditional corona-proof structure wire rod is easy to be bonded firmly or even to be internally unshelled after being formed, and the running safety of the stator wire rod is influenced.

Disclosure of Invention

In view of the above, the invention aims to develop a method for manufacturing a stator bar with a staggered corona prevention structure, the stator bar has the advantages of simple corona prevention structure, convenient process and easiness in design and manufacture, the multilayer corona prevention lap joint positions can be protected under the condition of improving the dielectric property of the bar, the bonding property of the corona prevention layers is enhanced, the uncontrollable resistance of the corona prevention layers and the corona prevention lap joint positions of the stator bar is avoided, and the stability of the corona prevention performance of the stator bar is ensured. The technical scheme of the invention is as follows:

the method comprises the following steps: of stator barsThe high-resistance anti-corona structure consists of an epoxy multi-glue powder mica tape, a silicon carbide middle-resistance anti-corona tape and a silicon carbide high-resistance anti-corona tape, wherein the thickness of the epoxy multi-glue powder mica tape is 0.14mm, the glue content is 37-40%, and the volume resistivity is high>10¹²Omega.m, a silicon carbide middle-resistance anti-corona band thickness of 0.12mm, and an inherent surface resistivity of 10¹¹～10¹²Omega, nonlinear coefficient of 0.5-1.0 cm/kV, silicon carbide high-resistance corona-proof band thickness of 0.12mm, and inherent resistivity of 10¹²～10¹³Omega, the nonlinear coefficient is 3-5 cm/kV;

step two: wrapping thickness d on the formed wire₀The main insulating material is wrapped with a layer of low-resistance corona-proof material in a half-lap winding way in the main insulating groove part and is wrapped at the middle-low resistance lap joint part;

step three: wrapping a layer of epoxy multi-glue mica tape on the low-resistance corona-proof material in a half-lap winding way, and covering the axial distance d of the low-resistance corona-proof material on one side₁4cm, the other side is covered with main insulating material for an axial distance d₁；

Step four: a layer of silicon carbide intermediate corona resistant tape is wrapped on the low-resistance corona resistant material and the epoxy multi-gelatine powder mica tape on the low-resistance corona resistant material in a semi-lap winding way, and the axial distance d of the epoxy multi-gelatine powder mica tape is covered₂＝2cm；

Step five: wrapping a layer of epoxy multi-glue mica tape on the silicon carbide intermediate-resistance anti-corona tape in a semi-lap winding manner, and covering the silicon carbide intermediate-resistance anti-corona tape at one side by an axial distance d₁4cm, the other side is covered with main insulating material for an axial distance d₁；

Step six: a layer of silicon carbide high-resistance anti-halation tape is wrapped in the silicon carbide middle-resistance anti-halation tape and the upper part of the epoxy multi-gelatine powder mica tape on the silicon carbide middle-resistance anti-halation tape in a semi-lap winding way, and the axial distance d of the epoxy multi-gelatine powder mica tape is covered₂＝2cm；

Step seven: after the lamination of the anti-corona layer with the staggered structure is finished, the formed lead is heated, pressurized, solidified and formed on a die in an internal heating mode, the heating speed is 1.5 ℃/min, when the temperature of a winding bar reaches 170 +/-5 ℃, the power is cut off after heat preservation is carried out for 5h, and when the die is naturally cooled to below 50 ℃, the die is removed.

In the seventh step of the manufacturing method of the stator bar with the staggered corona-proof structure, the formed conducting wire is cured and formed in an internal heating mode.

In the seventh step of the manufacturing method of the stator bar with the staggered corona-proof structure, the temperature rise speed of the formed lead is 1.5 ℃/min.

In the seventh step, the mold is removed when the mold is naturally cooled to below 50 ℃.

The invention has the beneficial effects that:

the invention provides a method for manufacturing a stator bar with a staggered corona-proof structure, which can achieve the following technical effects through an innovative method:

1. and protecting the multi-stage anti-corona lap joint position. Epoxy mica materials with more excellent mechanical and electrical properties are added between different anti-corona material layers, so that the anti-corona lap joint position is prevented from being exposed outside, and the anti-corona lap joint position is effectively protected and prevented from being damaged by external machinery or discharge;

2. the bonding performance of the anti-corona lap joint of the stator bar is improved. The content of resin and glass fiber cloth between anti-corona layers is increased by the multi-rubber powder mica material, the bonding performance of anti-corona lap joint parts is improved, and the situations of weak anti-corona bonding and unshelling of the end parts of the stator bars are effectively prevented;

3. and the dielectric property of the stator bar is enhanced. The main insulation thickness of the end part of the wire rod is increased by the multi-rubber powder mica material, and the dielectric property is improved;

4. the effective connection of electrical performance is guaranteed. Although the physical connection of different anti-corona materials is blocked by the multi-rubber powder mica material, the capacitive resistance of the thinner multi-rubber powder mica material under the power frequency alternating current voltage is very small, so that the effective electrical connection between anti-corona material layers can be still ensured, and the anti-corona effect is not influenced.

Drawings

FIG. 1 is a schematic cross-sectional view of a stator bar in a fault-tolerant corona shielding configuration.

The notation in the figure is: 1-epoxy multi-glue mica tape, 2-silicon carbide middle resistance anti-corona tape, 3-silicon carbide high resistance anti-corona tape, 4-formed conductor, 5-main insulating material, 6-low resistance anti-corona material and 7-middle and low resistance lap joint

Detailed Description

The present application is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present application is not limited thereby.

The method comprises the following steps: as shown in figure 1, the high-resistance corona-proof structure of the stator bar consists of an epoxy rich glue powder mica tape 1, a silicon carbide medium-resistance corona-proof tape 2 and a silicon carbide high-resistance corona-proof tape 3, wherein the thickness of the epoxy rich glue powder mica tape 1 is 0.14mm, the glue content is 37-40%, and the volume resistivity is high>10¹²Omega.m, a silicon carbide intermediate resistance corona band 2 with a thickness of 0.12mm and an inherent surface resistivity of 10¹¹～10¹²Omega, nonlinear coefficient of 0.5-1.0 cm/kV, silicon carbide high-resistance anti-corona band 3 with thickness of 0.12mm and inherent resistivity of 10¹²～10¹³Omega, the nonlinear coefficient is 3-5 cm/kV;

step two: as shown in FIG. 1, the formed wire 4 is wrapped with a thickness d₀The main insulating material 5 is wrapped with a layer of low-resistance corona-proof material 6 in a half-lap winding way in the main insulating groove part and is wrapped to a middle-low resistance lap joint part 7; the function of binding the main insulating material 5 in the step is to ensure the electrical strength and the mechanical strength of the stator bar, and the function of binding the low-resistance anti-corona material 6 in the step is to ensure the good grounding condition of the groove part of the stator bar.

Step three: as shown in figure 1, a layer of epoxy multi-glue mica tape 1 is wrapped on the low-resistance corona-proof material 6 in a half-lap winding way, and the low-resistance corona-proof material 6 is covered on one side by an axial distance d₁4cm, the other side is covered with a main insulating material 5 for an axial distance d₁(ii) a The purpose of binding the epoxy resin mica tape 1 in the step is to protect the low-resistance corona-proof material 6 and enhance the bonding effect between corona-proof layers.

Step four: as shown in figure 1, a layer of silicon carbide middle corona-resistant belt 2 is wrapped above the low-resistance corona-resistant material 6 and the epoxy rich-gelatine powder mica tape 1 on the low-resistance corona-resistant material in a half-lap winding way, and the epoxy rich-gelatine powder mica tape 1 is covered by an axial distance d₂2 cm; in the step, a layer of epoxy rich-rubber mica tape 1 exists between the silicon carbide middle corona-resistant tape 2 and the low-resistance corona-resistant material 6, and because the epoxy rich-rubber mica tape 1 is very thin and has very small capacitive reactance, the current between the silicon carbide middle corona-resistant tape 2 and the low-resistance corona-resistant material 6 is applied under the action of power frequency alternating currentThe transmission influence is small;

step five: as shown in figure 1, a layer of epoxy rich glue mica tape 1 is wrapped on a silicon carbide middle anti-corona tape 2 in a semi-lap winding way, and one side of the silicon carbide middle anti-corona tape 2 is covered by an axial distance d₁4cm, the other side is covered with a main insulating material 5 for an axial distance d₁(ii) a The process and principle of the step three are similar.

Step six: as shown in figure 1, a layer of silicon carbide high-resistance anti-corona tape 3 is wrapped above the silicon carbide middle-resistance anti-corona tape 2 and the epoxy rich-gelatine powder mica tape 1 on the silicon carbide middle-resistance anti-corona tape in a semi-lap winding way, and the silicon carbide high-resistance anti-corona tape 1 is covered by the epoxy rich-gelatine powder mica tape 1 for an axial distance d₂2 cm; the process and principle of the step four are similar.

Step seven: after the lamination of the anti-corona layer with the staggered structure is finished, the formed lead 4 is heated, pressurized, solidified and formed on a die in an internal heating mode, the heating speed is 1.5 ℃/min, when the temperature of a winding bar reaches 170 +/-5 ℃, the power is cut off after heat preservation is carried out for 5h, and when the die is naturally cooled to below 50 ℃, the die is removed; the mode of unloading the die after natural cooling is adopted in the step, so that the residual stress in the stator bar is eliminated as much as possible, and the performance of the bar is improved.

Further, in the seventh step, the molded conducting wire (4) is cured and molded in an internal heating mode.

Further, in the seventh step, the temperature rise speed of the formed wire is 1.5 ℃/min.

Further, in the seventh step, the mold is unloaded when the mold is naturally cooled to below 50 ℃.

The present invention is illustrative only and not intended to limit the scope thereof, and those skilled in the art can make modifications to the present invention without departing from the spirit and scope thereof.