A large-capacity steam turbine generator stator bar anti-hum manufacturing process

Abstract

The present application relates to the technical field of generator stator bar manufacturing, in particular to a large-capacity steam turbine generator stator bar anti-buckling manufacturing process, comprising the following steps: step one: transposing and braiding the stator bar to form a shaped stator bar; step two: pasting a semiconductor plate on both sides of the slot of the shaped stator bar respectively, and then gluing to obtain a glued stator bar; step three: overlapping 1 / 2 to wrap the main insulation mica tape; step four: overlapping 1 / 3 to wrap the low-resistance anti-buckling tape; step five: overlapping 2 / 3 to wrap the high-resistance anti-buckling tape; step six: overlapping 1 / 3 to wrap the low-resistance isolation anti-buckling tape to obtain an anti-buckling stator bar; step seven: overlapping 1 / 3 to wrap the polytetrafluoroethylene release tape; step eight: placing in a mold and drying to obtain a pretreated stator bar; step nine: performing vacuum impregnation treatment, heating and curing to obtain an impregnated stator bar; and step ten: removing the mold to obtain a finished stator bar. The manufacturing process is simple, environmentally friendly, and stable in anti-buckling effect.

Description

Technical Field

[0001] The invention relates to the technical field of generator stator wire bar manufacturing, and in particular to an anti-corona manufacturing process for large-capacity steam turbine generator stator wire bars. Background Art

[0002] A steam turbine generator is a synchronous generator driven by a steam turbine. During the power generation process, a steam turbine generator utilizes various energy sources, such as coal, natural gas, nuclear energy, and hydropower, to drive the turbine. The turbine acts as the prime mover, rotating the rotor and converting mechanical energy into electrical energy through the principle of electromagnetic induction. Steam turbine generators are characterized by high efficiency, stability, and large capacity, and are widely used in power generation, industrial production, and aerospace.

[0003] The most basic components of a steam turbine generator are the rotor, stator, excitation system, and cooling system. The rotor is the turbine generator's power source, converting mechanical energy into electrical energy. The stator is the key component for generating alternating current, consisting primarily of the stator core, stator windings, and frame. The stator core, a crucial component that forms the magnetic circuit and secures the stator windings, is typically constructed from laminated cold-rolled silicon steel sheets with excellent magnetic conductivity. The stator windings are coils formed by connecting stator bars inserted into the stator core slots at their ends. The stator bars of medium and small steam turbine generators are solid, while large steam turbine generators often utilize internally cooled bars to improve heat dissipation. For example, these bars consist of several solid bars connected in parallel with hollow bars that allow water to flow through them.

[0004] In recent years, the capacity of steam turbine generators has been continuously increasing with technological developments and improvements. However, when the voltage level of large-capacity steam turbine generators reaches a certain level, corona discharge is prone to occur. Corona discharge can cause the stator's main insulation material to gradually corrode and fail, eventually breaking down, threatening the unit's operational safety. Currently, the stator bars of large-capacity, high-voltage generators utilize a manufacturing process that combines an internal equipotential layer with an external anti-corona layer to address this corona discharge phenomenon. The internal equipotential layer of the stator bar is typically applied by applying a semi-conductive paint to the side of the stator bar before wrapping the main insulation. This semi-conductive paint is prone to falling off during subsequent handling or wrapping, and is ineffective in shielding the balanced electric field. The outer anti-corona layer is generally formed and cured by painting the main insulating mica layer, or the main insulating mica layer is dipped in paint and then wrapped with a conductive tape and then hot-pressed and cured. In addition, the ends of high-voltage stator wire bars generally require segmented anti-corona. This type of external anti-corona manufacturing process is mostly a discontinuous forming process. On the one hand, the multi-stage anti-corona process is relatively cumbersome. On the other hand, painting or dipping the main insulating mica layer in paint and then wrapping it with a conductive tape can easily cause environmental pollution and harm the health of employees. Summary of the Invention

[0005] To address the technical problem that corona discharge is prone to occur in stator bars of large-capacity steam turbine generators, the present invention provides an anti-corona manufacturing process for stator bars of large-capacity steam turbine generators. The process comprises first manufacturing an equipotential layer, then pre-treating the stator bars by sequentially wrapping them with main insulating mica tape, low-resistance anti-corona tape, high-resistance anti-corona tape, low-resistance isolation anti-corona tape, and polytetrafluoroethylene release tape from the inside out. The pre-treated stator bars are then placed in a mold for vacuum dipping. The main insulation and anti-corona treatment of the stator bars can be completed through only one dipping and curing process. The manufacturing process is simple and environmentally friendly, and the anti-corona effect is stable.

[0006] The technical solutions of the present invention are as follows:

[0007] A corona prevention manufacturing process for a large-capacity steam turbine generator stator bar comprises the following steps:

[0008] Step 1: Transpose the stator wire rods and weave them into a shape to obtain a formed stator wire rod;

[0009] Step 2: Use semi-conductive adhesive strips to adhere the semiconductor plates to both sides of the slot of the formed stator bar, and then heat to 150-170°C for gelation for 10-40 minutes to complete the formation of the equipotential layer and obtain the gelled stator bar;

[0010] Step 3: Wrap the main insulation mica tape on the outside of the gelled stator bar with an overlap of 1 / 2;

[0011] Step 4: Wrap low-resistance anti-corona tape on the core slot of the gelled stator bar wrapped with the main insulation mica tape, overlapping 1 / 3;

[0012] Step 5: Wrap high-resistance anti-corona tape between the two side edges of the low-resistance anti-corona tape and the end copper blocks at both ends of the gelled stator wire rod, overlapping by 2 / 3;

[0013] Step 6: Wrap the low-resistance isolation anti-corona tape on the outside of the low-resistance anti-corona tape by overlapping it by 1 / 3 to obtain the anti-corona stator bar. The wrapping direction of the resistance isolation anti-corona tape is opposite to that of the low-resistance anti-corona tape.

[0014] Step 7: Wrap the outer side of the anti-corona stator wire rod with polytetrafluoroethylene release tape overlapping 1 / 3;

[0015] Step 8: Place the anti-corona stator wire rod wrapped with polytetrafluoroethylene release tape into the mold and dry it at 100-120°C for 4-8 hours to obtain a pretreated stator wire rod;

[0016] Step 9: Vacuum-impregnate the pretreated stator wire rods, and then heat-cure them at 100-120° C. for at least 24 hours to obtain impregnated stator wire rods;

[0017] Step 10: Remove the mold of the varnished stator wire rod, clean the polytetrafluoroethylene release tape and resin chips of the varnished stator wire rod, obtain the finished stator wire rod, and transfer the finished stator wire rod to the quality inspection for electrical performance test.

[0018] Furthermore, in step 2, the semi-conductive adhesive strip is a conductive, semi-cured material with a volume resistivity of less than 5000 Ω·m, and the semiconductor plate is a conductive, rigid plate with a volume resistivity of 2000-20000 Ω·cm. The present invention first adheres the semiconductor plate to the outside of the semi-conductive adhesive strip to form an adhesive semiconductor plate. The inner side of the semi-conductive adhesive strip, which is adhesive to the semiconductor plate, is then adhered to both sides of the slot of the formed stator bar. Bonding the adhesive semiconductor plates to both sides of the slot of the formed stator bar not only fills the transposition grooves on the side of the formed stator bar, but also balances the electric field distribution of the stator bar.

[0019] Furthermore, in step 3, the main insulating mica tape is a low-resistance mica tape. Before wrapping the main insulating mica tape, first clean the sharp corners of the gelled stator wire rods and wipe the dust, debris and other debris on the surface of the gelled stator wire rods with a rag dipped in alcohol.

[0020] Furthermore, in step 4, the low-resistance anti-corona tape is a fully cured polyester-glass woven tape with a surface coated with conductive graphite, and the surface resistance of the fully cured polyester-glass woven tape with a small amount of conductive graphite is 1000-3000Ω.

[0021] Furthermore, in step 5, the high resistance anti-corona tape is a fully cured polyester fiber tape coated with silicon carbide on the surface, and the surface resistance of the fully cured polyester fiber tape coated with silicon carbide under a DC voltage of 5000V is 10 9 -10 13 The overlap between the high-resistance and low-resistance anti-corona tapes is 20 mm to ensure a smooth transition between the two. Silicon carbide coating the surface of the fully cured polyester tape can improve the electric field distribution at the stator slot opening by leveraging its nonlinear resistance properties.

[0022] Furthermore, in step six, the low-resistance isolation and anti-corona tape is a fully cured polyester-glass woven tape coated with a large amount of conductive graphite. The surface resistance of the fully cured polyester-glass woven tape coated with conductive graphite is 200-2000Ω. Coating the fully cured polyester-glass woven tape with a large amount of conductive graphite can reduce friction, improve the conductivity of the fully cured polyester-glass woven tape, and reduce resistance.

[0023] Furthermore, the distance between the side edge of the low-resistance isolation anti-corona band and the side edge of the proximal high-resistance anti-corona band is 1-3 mm. During the wrapping process, the low-resistance isolation anti-corona band should not be pressed on top of the high-resistance anti-corona band to ensure a smooth transition in resistance between the low-resistance and high-resistance anti-corona bands. The installation of the low-resistance isolation anti-corona band allows for thermal expansion and contraction and axial movement of the stator bars during operation after they are inserted into the core slots.

[0024] Furthermore, in step seven, the tetrafluoroethylene release tape has a porous structure with uniform pore distribution, and the pore diameter of the tetrafluoroethylene release tape is 0.7-0.8 mm; the number of pores per unit area of ​​the tetrafluoroethylene release tape is about 300 / dm 2 The use of a porous PTFE release tape with uniform pore distribution facilitates the separation of the varnished stator wire rod from the mold, preventing the anti-corona layer of the varnished stator wire rod from being damaged during the mold removal process.

[0025] Furthermore, in step nine, the vacuum dipping treatment includes vacuum drying treatment and pressure dipping treatment. During the vacuum drying period, the vacuum degree reaches below 0.2 mbar and is maintained for at least 10 hours. During the pressure dipping period, the pressure is 2.7-3.0 bar and is maintained for 10-20 hours. The surface resistance of the core slot portion of the dipping stator wire rod is 1000-8000Ω.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a large-capacity steam turbine generator stator wire bar anti-corona manufacturing process. First, equipotential layers are formed on both sides of the groove portion of the formed stator wire bar, and the equipotential layers are used to fill the transposition grooves on the sides of the stator wire bar, thereby ensuring the fastening effect of the stator wire bar and the stable and good balanced electric field effect; low-resistance anti-corona tape, high-resistance anti-corona tape and low-resistance isolation anti-corona tape are superimposed, and the wrapping positions and overlapping multiples of the main insulating mica tape, low-resistance anti-corona tape, high-resistance anti-corona tape and low-resistance isolation anti-corona tape are adjusted. Under the premise of ensuring the resistance value of the anti-corona tape, the axial slippage of the stator wire bar is improved, the anti-corona paint is dipped in one step for molding, the operation is simple, the process is environmentally friendly, and the anti-corona effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 This is a schematic diagram of the stator bar structure of Example 1.

[0030] In the figure, ①-formed stator bar, ②-equipotential layer, ③-main insulation mica tape, ④-low resistance anti-corona tape, ⑤-high resistance anti-corona tape, ⑥-low resistance isolation anti-corona tape. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0032] Example 1

[0033] A 220MW generator stator bar anti-corona manufacturing process comprises the following steps:

[0034] Step 1: On the automatic blanking machine platform, the stator wire rod strands are cut, pressed, transposed and bent, and then transposed and braided to form a formed stator wire rod.

[0035] Step 2: Attach the semiconductor board to the outside of the semi-conductive adhesive strip to form an adhesive semiconductor board. Attach the inner sides of the two semi-conductive adhesive strips that can be attached to the two sides of the slot of the molded stator wire bar. Then, heat to 155°C in a curing mold to gel for 35 minutes to complete the production of the equipotential layer and obtain the gelled stator wire bar.

[0036] Step 3: Clean the sharp corners of the gelled stator wire rods, and wipe the dust, debris and other debris on the surface of the gelled stator wire rods with a rag dipped in alcohol. Use an automatic taping machine to wrap the main insulating mica tape on the outside of the gelled stator wire rods, overlapping it by 1 / 2.

[0037] Step 4: Wrap a low-resistance anti-corona tape on the core slot of the gelled stator wire rod wrapped with the main insulating mica tape, overlapping 1 / 3 of the tape. The low-resistance anti-corona tape is a fully cured polyester-glass braided tape coated with conductive graphite. The surface resistance of the low-resistance anti-corona tape is 1000-3000Ω.

[0038] Step 5: Wrap high resistance anti-corona tape between the two sides of the low resistance anti-corona tape and the end copper blocks at both ends of the gelled stator wire rod, overlapping by 2 / 3. The high resistance anti-corona tape is a fully cured polyester fiber tape coated with silicon carbide. The surface resistance of the high resistance anti-corona tape is 10 at a DC voltage of 5000V. 9 -10 13 Ω, the overlapping length of the high-resistance anti-corona tape and the low-resistance anti-corona tape is 20 mm.

[0039] Step 6: Wrap the low-resistance isolation anti-corona tape around the outside of the low-resistance anti-corona tape, overlapping it by 1 / 3 in the opposite direction of the previous wrapping, to form the anti-corona stator bar. During the wrapping process, the low-resistance isolation anti-corona tape should not be pressed on top of the high-resistance anti-corona tape. The distance between the side edges of the low-resistance isolation anti-corona tape and the side edges of the proximal high-resistance anti-corona tape is 2mm. The low-resistance isolation anti-corona tape is a fully cured polyester-glass braided tape with a large amount of conductive graphite coated on the surface. The surface resistance of the low-resistance isolation anti-corona tape is 200-2000Ω.

[0040] Step 7: Wrap the outer side of the anti-corona stator wire rod with a porous polytetrafluoroethylene release tape with a pore diameter of 0.7-0.8mm, overlapping 1 / 3. The number of pores per unit area of ​​the porous polytetrafluoroethylene release tape is about 300 / dm 2 .

[0041] Step 8: Place the anti-corona stator wire rod wrapped with polytetrafluoroethylene release tape into a mold, and dry it in a drying kiln at 110° C. for 8 hours to obtain a pretreated stator wire rod.

[0042] Step 9: Vacuum impregnation of the pretreated stator bars in the VPI impregnation tank. This process includes vacuum drying and pressure impregnation. During the vacuum drying process, the vacuum is maintained at a pressure of less than 0.2 mbar for 12 hours. During the pressure impregnation process, the pressure is maintained at 2.8 bar for 20 hours. After vacuum impregnation, the stator bars are transferred to a drying kiln and cured at 110°C for 30 hours to obtain the coated stator bars. After vacuum impregnation, the surface resistance of the core slots of the coated stator bars is 1000-8000Ω at multiple points.

[0043] Step 10: Remove the mold of the varnished stator wire rod, clean the polytetrafluoroethylene demoulding tape and resin chips of the varnished stator wire rod, obtain the finished stator wire rod, and send the finished stator wire rod to the quality inspection for equipotential layer resistance value and electrical performance test of the whole wire rod. The test results are as follows: (1) The resistance value of the equipotential layer of the finished stator wire rod meets the standard requirement of less than 100kΩ, mainly concentrated in 15-80kΩ; (2) The surface anti-corona resistance of the finished stator wire rod in the low-resistance anti-corona area meets the requirement of 1000-8000Ω, mainly concentrated in 1500-7000Ω; ( 3) AC withstand voltage corona test: 1.5 times the corona condition was observed, far exceeding the 1.5Un (Un = 18kV) corona requirement, and generally reaching above 40kV; (4) AC withstand voltage test: without protective resistor, test voltage 48.6kV, 1 minute, passed; (5) AC withstand voltage test: with protective resistor, test voltage 64.8kV, 1 minute, passed; (6) Dielectric loss test: tgδ0.2Un = 9.08‰ (required ≤30‰); (Δtgδ / ΔU)max = 0.533[‰ / kV] (required ≤1[‰ / kV]). All the above electrical test data meet the technical standards for imported Alstom products.

[0044] Example 2

[0045] A 220MW generator stator bar anti-corona manufacturing process comprises the following steps:

[0046] Step 1: On the automatic blanking machine platform, the stator wire rod strands are cut, pressed, transposed and bent, and then transposed and braided to form a formed stator wire rod.

[0047] Step 2: Attach the semiconductor board to the outside of the semi-conductive adhesive strip to form an adhesive semiconductor board. Attach the inner sides of the two conductive adhesive strips of the adhesive semiconductor board to both sides of the slot of the formed stator wire bar. Then, heat to 165°C in a curing mold to gel for 20 minutes to complete the production of the equipotential layer and obtain the gelled stator wire bar.

[0048] Step 3: Clean the sharp corners of the gelled stator wire rods, and wipe the dust, debris and other debris on the surface of the gelled stator wire rods with a rag dipped in alcohol. Use an automatic taping machine to wrap the main insulating mica tape on the outside of the gelled stator wire rods, overlapping it by 1 / 2.

[0049] Step 4: Wrap a low-resistance anti-corona tape on the core slot of the gelled stator wire rod wrapped with the main insulating mica tape, overlapping 1 / 3 of the tape. The low-resistance anti-corona tape is a fully cured polyester-glass braided tape coated with conductive graphite. The surface resistance of the low-resistance anti-corona tape is 1000-3000Ω.

[0050] Step 5: Wrap high resistance anti-corona tape between the two sides of the low resistance anti-corona tape and the end copper blocks at both ends of the gelled stator wire rod, overlapping by 2 / 3. The high resistance anti-corona tape is a fully cured polyester fiber tape coated with silicon carbide. The surface resistance of the high resistance anti-corona tape is 10 at a DC voltage of 5000V. 9 -10 13 Ω, the overlapping length of the high-resistance anti-corona tape and the low-resistance anti-corona tape is 20 mm.

[0051] Step 6: Wrap the low-resistance isolation anti-corona tape around the outside of the low-resistance anti-corona tape, overlapping it by 1 / 3 in the opposite direction of the previous wrapping, to form the anti-corona stator bar. During the wrapping process, the low-resistance isolation anti-corona tape should not be pressed on top of the high-resistance anti-corona tape. The distance between the side edges of the low-resistance isolation anti-corona tape and the side edges of the proximal high-resistance anti-corona tape is 2mm. The low-resistance isolation anti-corona tape is a fully cured polyester-glass braided tape with a large amount of conductive graphite coated on the surface. The surface resistance of the low-resistance isolation anti-corona tape is 200-2000Ω.

[0052] Step 7: Wrap the outer side of the anti-corona stator wire rod with a porous polytetrafluoroethylene release tape with a pore diameter of 0.7-0.8mm, overlapping 1 / 3. The number of pores per unit area of ​​the porous polytetrafluoroethylene release tape is about 300 / dm 2 .

[0053] Step 8: Place the anti-corona stator wire rod wrapped with polytetrafluoroethylene release tape into the mold, and dry it in a drying kiln at 120° C. for 6 hours to obtain a pretreated stator wire rod.

[0054] Step 9: Vacuum impregnation of the pretreated stator bars in the VPI impregnation tank. This process includes vacuum drying and pressure impregnation. During the vacuum drying process, the vacuum is maintained at a pressure of less than 0.2 mbar for 12 hours. During the pressure impregnation process, the pressure is maintained at 3.0 bar for 18 hours. After vacuum impregnation, the stator bars are transferred to a drying kiln and cured at 120°C for 26 hours to obtain the coated stator bars. After vacuum impregnation, the surface resistance of the core slots of the coated stator bars is 1000-8000Ω at multiple points.

[0055] Step 10: Remove the mold of the varnished stator wire rod, clean the polytetrafluoroethylene demoulding tape and resin chips of the varnished stator wire rod, obtain the finished stator wire rod, and send the finished stator wire rod to the quality inspection for equipotential layer resistance value and electrical performance test of the whole wire rod. The test results are as follows: (1) The resistance value of the equipotential layer of the finished stator wire rod meets the standard requirement of less than 100kΩ, mainly concentrated in 20-80kΩ; (2) The surface anti-corona resistance of the finished stator wire rod in the low-resistance anti-corona area meets the requirement of 1000-8000Ω, mainly concentrated in 2000-6500Ω; ( 3) AC power frequency withstand voltage corona test: 1.5 times the corona condition was observed, far exceeding the 1.5Un (Un = 18kV) corona requirement, and generally reaching above 40kV; (4) AC power frequency withstand voltage test: without protective resistor, test voltage 48.6kV, 1 minute, passed; (5) AC power frequency withstand voltage test: with protective resistor, test voltage 64.8kV, 1 minute, passed; (6) dielectric loss test: tgδ0.2Un = 5.38‰ (required ≤30‰); (Δtgδ / ΔU)max = 0.064[‰ / kV] (required ≤1[‰ / kV]). All the above electrical test data meet the technical standards for imported Alstom products.

[0056] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be easily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention.

Claims

1. A corona prevention manufacturing process for large-capacity steam turbine generator stator wire rods, characterized in that: The steps include: Step 1: Transpose the stator wire rods and weave them into a shape to obtain a formed stator wire rod; Step 2: Use semi-conductive adhesive strips to adhere the semiconductor plates to both sides of the slot of the formed stator bar, and then heat to 150-170°C for gelation for 10-40 minutes to complete the formation of the equipotential layer and obtain the gelled stator bar; Step 3: Wrap the main insulation mica tape on the outside of the gelled stator bar with an overlap of 1 / 2; Step 4: Wrap low-resistance anti-corona tape on the core slot of the gelled stator bar wrapped with the main insulation mica tape, overlapping 1 / 3; Step 5: Wrap high-resistance anti-corona tape between the two side edges of the low-resistance anti-corona tape and the end copper blocks at both ends of the gelled stator wire rod, overlapping by 2 / 3; Step 6: Wrap the low-resistance isolation anti-corona tape on the outside of the low-resistance anti-corona tape by overlapping it by 1 / 3 to obtain the anti-corona stator bar. The wrapping direction of the resistance isolation anti-corona tape is opposite to that of the low-resistance anti-corona tape. Step 7: Wrap the outer side of the anti-corona stator wire rod with polytetrafluoroethylene release tape overlapping 1 / 3; Step 8: Place the anti-corona stator wire rod wrapped with polytetrafluoroethylene release tape into the mold and dry it at 100-120°C for 4-8 hours to obtain a pretreated stator wire rod; Step 9: Vacuum-impregnate the pretreated stator wire rods, and then heat-cure them at 100-120° C. for at least 24 hours to obtain impregnated stator wire rods; Step 10: Remove the mold of the varnished stator wire rod, clean the polytetrafluoroethylene release tape and resin chips of the varnished stator wire rod, obtain the finished stator wire rod, and transfer the finished stator wire rod to the quality inspection for electrical performance test.

2. The anti-corona manufacturing process for a large-capacity steam turbine generator stator bar according to claim 1, characterized in that: In step 2, the volume resistivity of the semi-conductive rubber strip is less than 5000 Ω·m, and the volume resistivity of the semiconductor plate is 2000-20000 Ω·cm.

3. The anti-corona manufacturing process for a large-capacity steam turbine generator stator bar according to claim 1, characterized in that: In step 3, the main insulating mica tape is a low-resistance mica tape.

4. The anti-corona manufacturing process for a large-capacity steam turbine generator stator bar according to claim 1, characterized in that: In step 4, the low-resistance anti-corona tape is a fully cured polyester-glass woven tape with a surface coated with conductive graphite, and the surface resistance of the fully cured polyester-glass woven tape with a surface coated with conductive graphite is 1000-3000Ω.

5. The anti-corona manufacturing process for large-capacity steam turbine generator stator bars according to claim 1, characterized in that: In step 5, the high resistance anti-corona tape is a fully cured polyester fiber tape coated with silicon carbide on the surface. The surface resistance of the fully cured polyester fiber tape coated with silicon carbide under a DC voltage of 5000V is 10 9 -10 13 Ω, the overlapping length of the high-resistance anti-corona tape and the low-resistance anti-corona tape is 20 mm.

6. The anti-corona manufacturing process for large-capacity steam turbine generator stator bars according to claim 1, characterized in that: In step six, the low-resistance isolation and anti-corona tape is a fully cured polyester-glass woven tape with a surface coated with conductive graphite, and the surface resistance of the fully cured polyester-glass woven tape with a surface coated with conductive graphite is 200-2000Ω.

7. A corona prevention manufacturing process for a large-capacity steam turbine generator stator bar according to claim 6, characterized in that: The distance between the side edge of the low-resistance isolation anti-corona belt and the side edge of the proximal high-resistance anti-corona belt is 1-3 mm.

8. The anti-corona manufacturing process for large-capacity steam turbine generator stator bars according to claim 1, characterized in that: In step seven, the tetrafluoroethylene release tape has a porous structure with uniform pore distribution, and the pore diameter of the tetrafluoroethylene release tape is 0.7-0.8 mm.

9. The anti-corona manufacturing process for large-capacity steam turbine generator stator bars according to claim 1, characterized in that: In step nine, the vacuum dipping treatment includes a vacuum drying treatment and a pressure dipping treatment, and the surface resistance of the core slot portion of the dipping stator bar is 1000-8000Ω.

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