BG67276B1 - Sections and half-sections with vpi insulation system for high voltage electrical machines and method for production thereof - Google Patents

Abstract

Stator multiple-turn section and half-section (rod) for high-voltage electrical machines with a highly efficient insulation system, made by the VPI /Vacuum Pressure Impregnation/ method with improved technical performance. The elemental copper conductors are arranged according to the type of section, as each conductor has conductive insulation. The multiple-turn section is insulated with corps insulation, then corona protection tapes are applied - in the straight of the section with conductive corona protection tape, and right after it in the direction of the front parts there is a semiconducting corona protection tape. The bent front parts of the section (outside the dimensions of the stator group) are covered with a protective porous tape and thus formed, the multiple-turn section after winding and connections together with the stator group is impregnated with impregnation varnish. In the half-section, there is a vertical separator between the rows of conductors, a transposition separator on the thin part and a transposition filler in the upper and lower part, as well as thereafter are applied the corps insulation, the conductive and semiconductive corona protection tapes and the protective porous tape. Thus formed, the half-section is impregnated with impregnation varnish.

Description

(54) SECTIONS AND SEMI-SECTIONS WITH VPI INSULATION SYSTEM FOR HIGH VOLTAGE ELECTRICAL MACHINES AND METHOD FOR THEIR PRODUCTION

Field of technology

The present invention relates generally to a half-section (stator or rotor rod) and a stator multi-winding section for rotating electrical machines with a highly stable and highly efficient vacuum-press impregnated insulation system that improves the energy parameters and energy efficiency of the machine. In particular, the invention relates to a half-section (stator or rotor rod) made by VPI technology (vacuum-press impregnation) and a stator multi-winding section made by Global VPI technology for rotating electric machines with a highly efficient insulation system.

BACKGROUND OF THE INVENTION

Methods are known (Resin Rich or other older technologies) for making a half-section (stator or rotor rod) for rotating electric machines for low, medium and high voltage, in which pre-cut and cut elementary copper profile conductors are cleaned, bent and transpose to each other. The individual elementary wires are arranged parallel to each other and intertwined in two rows, representing the half-section. A vertical separator is placed between the two vertical rows of wires, and a transposition separator, insulating (transposition) fillers and equalizers are placed under the transposed wires (along the thin part of the half-section) during the transition from one half-branch to the other. The stator half-section is then placed in special equipment where it is heated to a certain temperature for a certain time interval and at a certain pressure regime in order to achieve optimal geometry and at the same time polymerization of the epoxy-novolac components of the conductor insulation system and achieving the desired initial (output) transverse geometry, which is the output base for the construction of the main (the main, also called hull) insulation.

It stays at this temperature for the time required for polymerization and cools smoothly. After cleaning and tests, the front parts of the stator half-section are formed according to the stator parameters, the ends of the individual conductors are soldered to each other and the front parts are coated with electrical insulating epoxy resin. On the half-section (stator or rotor rod) the main (main, also called housing) insulation is applied along the entire length, conducting protective tape in the active (stator) part, semiconducting protective tape outside the stator package (before the front sections), special protective tapes (in the front parts) depending on the working power, voltage and the chosen method and technology for polymerization and configuration and finally the half-section (stator or rotor rod) is baked in a device for final shaping of all parts at a specific time-temperature regime and at a certain pressure. The parameters time, temperature and pressure are a function of many factors, the main ones being the type of insulation system, the operating power and voltage, as well as the temperature class of the rotating electric machine.

Insulated or bare elementary copper conductors with a rectangular cross section are wound during the production of the multi-winding section (according to the Resin Rich methods used so far or other older technologies). The number of parallel copper conductors connected in parallel is one or more (in each winding), and they are arranged parallel to each other, one on top of the other or one next to and on top of each other.

BG 67276 Bl on their narrow panels and are insulated with winding (conductor) insulation. The composite conductor (wire bundle) thus obtained is then wound on a template with the required number of turns (two or more) and the elements of the thus formed unformed multi-winding section are wrapped with a protective layer of tape for stretching, forming and configuring the section according to stator parameters. In the next operation, the elements of the active parts of the multi-winding section are coated with electrical insulating epoxy resin and insulated with thermosetting tapes, after which the first heat pressing is performed to initially configure the active parts and achieve the desired transverse geometry. more hull) insulation, at a specific time-temperature regime and pressure.

After cleaning and performing mechanical and electrical tests, the laying of the main (main, also called hull) insulation of the section of thermosetting insulation strips in the active parts (channel sections) and laying of thermoplastic insulation strips in the front parts is performed. Here, the connection of the thermosetting type insulation (insulation of the channel parts) with that of the thermoplastic type (insulation of the front parts) is done by a specific overlap of the different layers of the types (thermoplastic and thermosetting) strips in a cone-like manner. Then a strip of corona protection tape is placed on the main (also called the body) insulation. The straight parts of the section, which are placed in the stator channel, are covered with conductive corona protection tape, and immediately after it at the beginning of the bent parts of the section (with guaranteed contact between the layers of the two corona protection tapes) is placed a semiconducting corona protection tape (as a function of operating voltage). The next operation is a second heat pressing of the housing insulation in the area of the channel sections (straight parts), which is performed in special equipment (specifically made for each different type of section, as in the first heat pressing), at a specific time-temperature regime and pressure. polymerization of thermosetting insulation, final configuration and achievement of specific geometry.

This is followed by cleaning, checking the geometric configuration and dimensions, electrical tests, placing protective strips in the front parts and final (secondary) polymerization of the thermosetting insulation (in the active parts) and configuration (semi-compression of the shrinking protective strips) of the thermoplastic insulation in the front parts.

All sections and half-sections produced by the described two methods have a relatively high production duration and cost due to the high energy consumption of the method and unsatisfactory technical indicators such as:

- relatively low moisture resistance;

- relatively low resistance when working in aggressive environments;

- relatively low mechanical resistance;

- the presence of a "cone" (transition from thermosetting, in the channel parts, to thermoplastic, in the front parts, insulation);

- unsatisfactory insulation stock ratio;

- unsatisfactory resistance to partial discharges.

There is a growing need for the production of rotating electrical machines with an insulation system that ensures improved energy performance, and hence increase energy efficiency in the use of machines, combined economic

BG 67276 Bl efficiency in the production of these rotating electric machines for low, medium and high voltage.

This necessitates the development of new models of sections and semi-sections, as well as new methods for building a highly efficient insulation system with increased resistance to external moisture, chemical and mechanical influences, with better homogeneity, lower thickness and increased dielectric strength. of the main (the main, also called corpus) insulation, which successfully and cost-effectively to replace the known solutions.

Technical essence of the invention

The present invention relates to sections and semi-sections (for stator and rotor windings) for low, medium and high voltage rotating electrical machines with highly stable and at the same time high-efficiency vacuum-press impregnated insulation system (VPI insulation system) with improved technical performance, with reduced duration and cost of its production.

For the half-sections (rods) this is achieved by pre-cut and cut elementary copper profile conductors are cleaned, bent and transposed to each other. The individual elementary wires are arranged parallel to each other and are woven in two rows, representing the stator half-section (as in the case of the Resin Rich insulation system or other older technologies). A vertical separator is placed between the two vertical rows of wires, and a transposition separator, insulating (transposition) fillers and equalizers are placed under the transposed wires (along the thin part of the section) and the half-section (rod) is packed.

Thus formed, the half-section (rod) undergoes heat treatment to achieve the necessary output configuration for the construction of the main (also called the hull) insulation system. The main insulation is based on the so-called dry, porous tapes (tapes whose composition includes mainly carrier - fiberglass, PET film, kapton, PET - fleece or other similar backing media and protections), pressed mica paper attached to the carrier with resin, latent polymerization accelerators, if not contained in the VPI resin impregnating resin, and other reinforcing ingredients that are impregnated with the resin in the vacuum press impregnation process. On the half-section is applied the main (main, also called hull) insulation, the thickness (number of layers) of which is a function of the operating voltage, power and mode of operation of the particular rotating electrical machine, conducting and semiconducting corona protection strips, whose parameters are also operating voltage function, front protection strips and other special protective strips.

Thus prepared half-sections (rods) are placed in a special facility, heated to a certain temperature and kept at this temperature for a certain period of time (time and temperature are specific - according to the prescription for corona protection materials of each company producing insulation materials), at which the conductive and semi-conductive tapes harden and when impregnated on the rod do not allow the conductive substances from the corona protection tapes to pass into the varnish (also called impregnation resin). Then the half-sections (rods) are placed again in special equipment and these equipment (together with the half-sections prepared for the process) are arranged in a special vacuum-pressurized hermetic impregnation chamber.

The following are several interconnected sequential processes that take place in the impregnation sealed vessel:

1. Heating and complete tempering of everything in the working volume of the vessel.

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- when using materials for VPI process of different companies, the temperature levels may be close, but may still differ depending on the insulation strips (thermal class - F, H, C), the type of resin (manufacturer, component and other parameters);

- the required time is a direct function of the heated volume, the heating power and the heating mode.

2. Vacuuming the entire working volume through a coarse vacuum to achieve a fine vacuum (of the order of 0.2 Torr, 2.2 x 10 ² Pa or <0.2 mbar) in order to remove moisture, air inclusions and all other volatile substances from the insulation. system.

The criterion for completion of the process is to stop the reduction of the vacuum value and to keep the same value for 15 ^ 30 min again depending on the vacuumed volume.

During this time, the resin in the storage vessel was heated from 5 ° C to the temperature in the impregnation vessel and deaerated with a vacuum of 10 to 0.1 mbar and propyl (the air inclusions - bubbles were removed from it).

3. This is followed by "flooding" of the half-sections (rods) with impregnation resin (one or two-component - depending on the choice of the manufacturer), which is first sucked into the vessel from the vacuum to its reduction and equalization with atmospheric pressure, and then the resin is fed into the vessel with a pressure which rises rapidly and reaches 5- ^ 7 atm (bar). The process of penetration (soaking) of the resin into the entire insulation system of dry porous strips ends with soaking to the separators.

The main criterion for the completion of the process of impregnation of "dry porous insulating materials" is the cessation of the increase in the capacity of the system with electrodes conductor (Cu) facility (Fe).

4. Then maintain the pressure (5 ^: 7 atm) from 1 to 4 hours (depending on the type of insulation system - 0.4; 0.69; 3.0; 3.3; 6.3; 10.5; 13.5 or 20 kV). This creation of 5TO bar pressure on the resin in the hermetic chamber is for the purpose of complete impregnation in the insulation system.

5. The next step is to empty the impregnation vessel from the resin, which is initially performed by the pressure created in the vessel (5 ^ -7 atm), but its gradual equalization (of the pressure in the vessel) with the atmospheric one leads to the need to include and pump the resin from the impregnation vessel to the storage vessel.

The impregnated half-sections (rods) are drained from the excess resin and, as in the special device for pressing and forming its active part (the right part of the half-section), are placed in a special furnace, where the interaction between the catalyst takes place at a specific time-temperature regime. in the dry porous insulating materials and the resin impregnated in them. This interaction leads to a thermosetting reaction, which under the influence of temperature (in this case the temperature catalyzes the polymerization process) transforms the resin impregnated into the insulation system, from liquid phase through gel phase to solid glassy consistency (binder) - polymerizes and forms homogeneous glassy mass for the whole insulation system.

The present invention also encompasses a stator multi-winding section for medium and high voltage rotating electrical machines with a stable, highly efficient vacuum-press impregnated insulation system type Global VPI with improved technical performance - greatly increased mechanical

BG 67276 Bl strength, resistance to aggressive influences, increased dielectric strength, reduced one-sided insulation thickness (in mm), with reduced duration and cost of its production.

The multi-winding section is wound with insulated elementary copper conductors with a rectangular cross section. The number of elementary copper conductors connected in parallel is one or more, as they are arranged parallel to each other, one on top of the other or one next to and on top of each other on their narrow planes and are insulated with winding (conductor) insulation. The composite conductor thus obtained is wrapped with a layer of protective (protective) tapes mainly in the areas of the active parts in order to heat compress and configure the cross section of the active (channel) parts by heat pressing - similar to the Resin Rich insulation system.

This is followed by complete insulation of the section (without interruption of the insulation layers) with the main insulation (dry porous) tape, which is the main (the main, also called housing) insulation. The straight (active) parts of the section, which are placed in the stator channel, are covered with conductive corona protection tape, and immediately after it, along the section in the direction of the front parts, a semi-conductive corona protection tape is placed, and finally the front parts are covered with one layer of protective porous (retaining the resin in the direction from the inside to the outside) tape.

The insulated section is heated to about 80-100 ° C and kept at this temperature for a certain period of time (depending on the prescription of the manufacturer of insulation materials), where the conductive and semi-conductive tape hardens and impregnation of the multi-winding section there is no possibility for the conductive substances from the corona protection tapes to pass into the varnish (impregnation resin).

The section thus prepared is laid (coiled) in the stator channels, reinforced in the channels and sections to each other, the sections are soldered according to the winding scheme, the solders are insulated with the same (as the housing insulation) insulating tape.

The coiled stator with the sections laid, reinforced and soldered according to the scheme is placed in a hermetic impregnation chamber and the same vacuum-press-impregnation process is carried out as in the half-sections (rods) described above.

The only difference here is that the role of the forming devices for the transverse and longitudinal geometry in the active (channel) parts of the windings (sections) is played by the channel in the assembled package. This clearly determines that the insulation system of the entire stator coiled is impregnated, together with all elements and together with the package, as well as the fact that the polymerization of the insulation system becomes global - polymerization of sections, connections, reinforcing and spacer elements, components and package.

That is why this type of insulation system is known as Global VP1.

Explanation of the attached figures

Figure 1a is a half section (stator or rotor rod) of a high voltage electric machine with an insulation system constructed by the VPL method

Figure 1b is the three sections of the half-section (stator or rotor rod) of Figure 1a with the designation of the individual parts and components.

Figure 1c is a spatial sectional view of the transition from the active to the front of a half-section (stator or rotor rod) of Figure 1a with an indication of the individual parts and components.

Figure 2a is a multi-winding section for a Global VPI type insulation system.

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Figure 26 is the three cross-sections of a multi-winding section for a Global VPI type insulation system of Figure 2a with an indication of the individual parts and components.

Figure 2c is a cross-sectional spatial model of the transition from the active to the front part of a multi-winding section of a high-voltage electric machine with one elementary conductor, for a Global VPI type insulation system of Figure 2a with designation of individual parts and components.

Examples of the invention

The invention is a stator multi-winding section and a half-section (rod) for medium and high voltage electric machines with a highly efficient insulation system with improved technical performance.

Figure 1a shows a half section (rod) of a medium and high voltage electric machine with an active part 20 of the half section (rod) and front parts 10.

Figure 16 shows the three cross-sections of the rod of Figure 1a. Sections A-A and BB show the pre-cut and cut elementary copper conductors 1, arranged in parallel one above the other and next to each other, woven in two parallel rows (branches), constituting the half-section, each conductor having a conductor insulation 2. Between the two rows (branches) there is a vertical separator 3, and on the thin part of the half-section (when passing a wire from one to the other row (branch) and a transposition separator 4. There is also a transposition filler 5 in the upper and lower part of the rod, which is located at both ends perpendicularly and above the vertical separator 3 and parallel and above the transposition separator 4. On the thus formed structure are applied the main (also called housing) insulation 6 and conductive corona protection tape 7. In the curved parts we have a semiconductor corona protection tape 8 (in section BB) In the front parts 10 (in section BB) there is no vertical separator 3, transposition separator 4 and transposition full wire 5, the conductive corona protection tape 7 and the semi-conductive corona protection tape 8, and on the main (also called housing) insulation 6 we directly have a protective porous tape 9. vitreous mass of insulation.

In one embodiment, when the preparation for laying the main insulation is according to the VPI system, as a material for the vertical 3 and transposition 4 separators is used an insulating material with composition and relative weight in g / m: highly absorbent material based on PET (polyethylene terephthalate) cotton wool with a thickness of 1 ^ 2 mm and a relative weight of 50 ^ -348 g / m ² , as the PET wool in this composition has a density of 4 <-10 g / m ² and an accelerator for epoxy anhydrite system with a density of 500- ^ 1100 mg / m ² .

In another embodiment, when the preparation for laying the main insulation is according to the Resin Rich system, the materials used for the vertical separator 3, the transposition separator 4 and the transposition filler 5 are as follows:

The vertical separator 3 is a well-resinous material with a thickness of 1 ^ -1.2 mm and a weight of 768- ^ 938 g / m ² comprising double-sided glued pressed insulating paper (eg Nomex paper) with a thickness of 0.25 mm and a weight of 230 ^ 264 g / m ² , glass wool 108- ^ 132 g / m ² and resin 435- ^ 535 g / m ² .

Transposition separator 4 has a composition and relative weight in g / m ² : mechanically stable and resin-rich material with a thickness of 0.8-1.3 mm and a weight of 715 ^ 894 g / m ² including epoxy fiberglass with a thickness of 0.13 ^ -0.20 mm and a weight of 118 ^ -262 g / m ² , glass wool with a weight of 108- ^ 132 g / m ² and a resin with a weight of 493- ^ 600 g / m ² .

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The transposition filler 5 is a material with a composition and relative weight in g / m ² : strongly resinized mica paper with a thickness of 0.2-3.0 mm and a weight of 365 ^ 5607 g / m ² , including respectively mica paper 230: 312 g / m ² and resin 135 -2295 g / m ² .

After the first configuration and consolidation of the active part of the half-section (rod) formation of the structure, regardless of the type of system (VPI or Resin Rich), the main (main, also called hull) insulation 6 is laid, which is generally multilayer, as all layers have the same composition and structure, each layer is composed of two-layer or three-layer tape material and the insulation is composed of a carrier (fiberglass, PET - film, Kapton, PET - fleece or other material depending on the operating voltage, power, operating mode and temperature mode), on which is applied by a special technology mica (eg Micapaper), which is glued to the carrier with resin (silicone or other material), as in the composition of the insulation there are also various accelerators for polymerization of the impregnation varnish (impregnation resin) in the construction of the insulation system by the method of VPI.

In one embodiment, the main (also called hull) insulation 6 is a material with a composition and relative weight in g / m ² : high-absorption mica paper of uncalcified mica coated with a thin carrier layer of PET wool impregnated with an polymerization accelerator of the impregnation varnish (impregnation resin), with a thickness of 0.11-4.18 mm and a density of 191 ^ 245 g / m ² , a layer of PET wool with a thickness of 0.03 mm and a density of 4044 g / m ² , resin4 <12 g / m ² , polymerization accelerator 300 ^ -500 mg / m ² , breakdown voltage> 5 kV.

In another embodiment, the main (main, also called hull) insulation 6 is a material based on highly absorbent mica paper of uncalcified mica coated with a thin carrier layer of fiberglass impregnated with a polymerization accelerator of the impregnation varnish (impregnation resin), with a thickness of 0.11 -0.20 mm and density 181-5322 g / m ² , with data on the components - mica paper with a density of 145-5270 g / m ² , fiberglass with a thickness of 0.04 mm and a density of 23-526 g / m ² , resin with a density of 14-527 g / m ² , polymerization accelerator 300-700 mg / m ² , breakdown voltage> 2 kV.

The conductive corona protection strip 7 is made of polyester wadding (matt) impregnated with varnish (impregnation resin), containing carbon: polyester wadding with a thickness of 0.10: 0.15 mm, weight 50421 g / m ² and surface resistance 404 500 Ω.

The semiconducting corona protection strip 8 is a polyester fabric impregnated with a silicone-carbon mixture in B stage or a special resin with a total thickness of 0.11-4), 32 mm and a weight of 225-5395 g / m ² and a surface resistance of 0.5 x 10 ⁸ h-] χ 10 ¹⁰ Ω.

Protective porous tape 9 is composed of mixed polyester glass fiber tape impregnated with resin mixed with accelerator (metal salt, zinc naphthenate) with data: thickness 0.084.10 mm, total density 77 ^ -95 g / m ² , glass polyester fibers 2248 g / m ² , PET film 25-529 g / m ² , resin 30- ^ 38 g / m ² , accelerator 250-450 mg / m ² and breakdown voltage> 3 kV.

The impregnation varnish (impregnation resin), in one embodiment, has the composition and data: bisphenol-A epoxy resin with a density of 1.14.2 g / cm ³ , resin content 171 ^ 176 g / eq, total chloride content 0, 34-4.35%, hydrolyzed chloride 0.14-4.16%, flash point> 200 ° C, viscosity <5000 mPas at 25 ° C and <20 mPas at 60 ° C; liquid acid anhydride hardener with a density of 1.1 ^ -1.2 g / cm ³ , acid number 640-680 mgKOH / g, free acid content <2%, ignition temperature 170 ° C, vapor pressure 0.0033 / 0.1 mbar, viscosity <60 mPas at 25 ° C and <20 mPas at 60 ° C.

BG 67276 Bl

Figure 1c shows a spatial cross-sectional model of the transition from the active to the front part of the half-section (rod) of Figure 1a with the designation of the individual parts and components. The direction to the front part is 11 and the direction to the stator package (active part) is 12. The pre-cut and cut elementary copper conductors 1, arranged in parallel one above the other and next to each other, woven in two parallel rows (branches), constituting the half-section, each wire has a wire insulation 2. Between the two rows (branches) of wires there is a vertical separator 3, and on the thin part of the half-section (when passing a wire from one row to the other (branch) and a transposition separator 4. A transposition filler 5 is also available. In the upper and lower part of the rod the main (main, also called hull) insulation 6 and conductive corona protection tape 7 are applied on the thus formed structure. In the curved parts we also have a semiconducting corona protection tape 8. separator 4 and transposition filler 5, conductive corona protection strip 7 and semiconductor corona protection strip 8, as on the main (main, of also said hull) insulation 6 directly we have a protective porous tape 9.

Figure 2a shows a multi-winding section for a Global VPI type insulation system with an active part of the section 20 and a front part of the section 10.

Figure 26 shows the three cross-sections of a multi-winding section for a Global VPI type insulation system of Figure 2a. In sections A-A and BB, insulated elementary profile copper conductors 1 with a rectangular cross-section are visible, and the number of connected in parallel elementary copper conductors 1 can be one or more and are arranged parallel to each other, on top of each other or one next to and on the other along their narrow planes (when using a group conductor) and are insulated with conductor insulation 2. On the stator multi-winding section is applied the main (the main, also called housing) insulation 6, conducting corona protection tape 7. In the curved parts we have and a semiconducting corona protection strip 8 (at section BB). In the front parts 10 (at section B-B) there is no conductive corona protection strip 7 and semi-conductive corona protection strip 8, and on the main (main, also called hull) insulation 6 we directly have a protective porous strip 9. The stator multi-winding section and connecting the stator winding together with the stator package is impregnated by the VPI method with an impregnating varnish (impregnating resin) to achieve a homogeneous glassy mass of insulation and monolithicity of the stator package and stator winding.

The main (main, also called housing) insulation 6 is in the most general case multilayer, as all layers have the same composition and structure, each layer is composed of two-layer or three-layer tape material, and the insulation is composed of carrier (fiberglass, PET - film, Kapton, PET - fleece or other material depending on the operating voltage, power, operating mode and temperature mode), on which a mica (eg Micapaper) is applied by a special technology, which is glued to the carrier with resin or other material), as in the composition of the insulation there are also various accelerators for polymerization of the impregnation varnish (impregnation resin).

In one embodiment, the main (also called hull) insulation 6 is a material with a composition and relative weight in g / m ² : high-absorption mica paper of uncalcified mica coated with a thin carrier layer of PET wool impregnated with an polymerization accelerator of the impregnation varnish (impregnation resin), with a paper thickness of 0.1 1-0.18 mm and a density of 191 ^ 245 g / m ² , a layer of PET wool with a thickness of 0.03 mm and a density of 40 ^ 44 g / m ² , resin 4 <12 g / m ² , polymerization accelerator 300-500 mg / m ² , breakdown voltage> 5 kV.

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In another embodiment, the main (main, also called hull) insulation 6 is a material based on highly absorbent mica paper of non-calcined mica coated with a thin carrier layer of fiberglass impregnated with a polymerization accelerator of the impregnation varnish (impregnation resin), with a thickness of 0.1 1 = 0.20 mm and density 181- = 322 g / m ² , with data on the components - mica paper with a density of 145 = -270 g / m ² , fiberglass with a thickness of 0.04 mm and a density of 23 = -26 g / m ² , resin with a density of 14 ^ 27 g / m ² , polymerization accelerator 300 ^ 700 mg / m ² , breakdown voltage> 2 kV.

The conductive corona protection strip 7 is made of polyester wadding (matt) impregnated with varnish (impregnation resin) containing carbon: polyester wadding with a thickness of 0.10 = -0.15 mm, weight 50 ~ 121 g / m ² and surface resistance 40- > 1500 Ω.

The semiconducting corona protection tape 8 is a polyester fabric impregnated with a silicone-carbon mixture in B stage or a special resin with a total thickness of 0.11 = 0.32 mm and a weight of 225 = -395 g / m ² and a surface resistance of 0.5 x 10 ⁸ = -1 x 10 ¹⁰ Ω.

The protective porous strip 9 consists of a mixed polyester glass fiber strip impregnated with resin mixed with an accelerator (metal salt, zinc naphthenate) with data: thickness 0.08 = -0.10 mm, total density 77 = -95 g / m ² , glass polyester fiber 22 = -28 g / m ² , PET film 25 = -29 g / m ² , resin 30 = -38 g / m ² , accelerator 250 = -450 mg / m ² and breakdown voltage> 3 kV.

The impregnation varnish (impregnation resin), in one embodiment, has a composition and data: bisphenol-A epoxy resin with a density of 1.1 = -1.2 g / cm ³ , resin content 171 = 476 g / eq, total content of chloride 0.34 = -0.35%, hydrolyzed chloride 0.14 = -0.16%, flash point> 200 ° C, viscosity <5000 mPas at 25 ° C and <20 mPas at 60 ° C; liquid acid anhydride hardener with a density of 1.1 = -1.2 g / cm ³ , acid number 640 = -680 mgKOH / g, free acid content <2%, ignition temperature 170 ° C, vapor pressure 0, 0033 / 0.1 mbar, viscosity <60 mPas at 25 ° C and <20 mPas at 60 ° C.

Figure 2c shows a spatial cross-sectional model of the transition from the active to the front part of a multi-winding section of a high-voltage electric machine with one elementary conductor, for a Global VPI type insulation system of Figure 2a with designation of individual parts and components. The direction to the front part is 11 and the direction to the stator package (active part) is 12. The insulated elementary profile copper conductors 1 have a rectangular cross section, and the number of connected in parallel elementary copper conductors 1 can be one or more (if group conductor bundle) and are arranged parallel to each other, one on top of the other or one next to and on top of each other on their narrow planes and are insulated with conductor insulation 2. The main (also called housing) insulation 6 and conductive corona protection tape 7. In the curved parts there is also a semiconducting corona protection tape 8. In the front parts 11 there is no conductive corona protection tape 7 and semi-conductive corona protection tape 8, and on the main (main, also called housing) insulation 6 there is a protective porous tape 9.

Test results:

High-voltage electrical tests for quality and durability of the insulation system built by the VPI method:

DF values (insulation quality):

- initial values at 0.2 Un <0,02 at room temperature

- increase: max Δ tan δ <0,02

- tan δ at 155 ° C <0,1

Stress resistance or according to international standards; IEEE 1553: sample for U _n = 10.5 kV has been tested for U _n = for 13.8 kV

A) 35 kV - »250 h - OK

C) 28 kV - 400 h - OK

Sample A) - 380 h and 22 min

Sample B) - 425 h and 07 min

Thermal cycle: according to IEC or IEEE 1310

Detected breakdown voltages according to the requirements of IEC 60034, for tested samples of 3.3 kV, 6.3 kV, 10 kV and 13.8 kV> 4.5 Un.

Test results of different samples at 4 levels of operating voltage:

Rated voltage Initial value of tan δ Hot tan δ Max. Δ tan δ Partial discharges Minimum breakdown voltage 3.3 kV 0.01 0.1 0.01 <1000pC 4Un 6.6 kV 0.01 0.1 0.01 1000-2000рС 4Un 10.5 kV 0.01 0.1 0.01 2000-3000pC 4Un 13.8 kV 0.01 ο.ι 0.01 3000-4000рС 4Un

The obtained results are very good and exceed the values of the samples known so far. The increased dielectric strength of the section insulation allows to reduce its thickness, while preserving the parameters of the stator magnetic conductor in its channels frees up space for more conductive material, ie increases the cross section of the conductors and reduces losses in the stator winding, respectively the efficiency of the machine increases. In addition, the VPI insulation system is practically completely non-hygroscopic and can function without problems in high humidity and environmental pollution.

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Application of the invention

The half-sections and sections for rotating electric machines for low medium and high voltage are used for the production of stator and rotor windings of rotating electric machines with medium and high power - hydro generators, turbogenerators, electric motors, which are designed to work at low, medium and high voltage, usually 400 V, 690 V, 3300 V, 6300 V and higher. They are used to generate electricity, to drive powerful units such as pumps, mills, conveyor belts and more. With these rotating electric machines, both the production cost and the energy efficiency in the operation of the machine are essential. The proposed invention for semi-sections and sections allows to achieve a reduction in production cost and reduction of operating costs due to increased energy efficiency of machines and increased efficiency, as well as the ability to operate in degraded environmental conditions, such as humidity, dust , high temperature, etc.

An advantage of the present invention is the reduced duration and energy consumption of the manufacturing process, which leads to a reduced cost of production by up to 20%.

BG 67276 Bl

Significant improvement of the main technical parameters characterizing the stator windings (half-sections or the whole stator coiled in Global VPI) of rotating electric machines for low, medium and high voltage, such as:

- homogeneity and continuity of the insulation (lack of cone and two types of insulation - thermosetting and thermoplastic);

- reduced average one-sided insulation thickness by 40%;

- increased total dielectric strength - up to 2 times;

- increased rate of stock (K _3anaca [o.e.] = and _the drill [kV] / test [kV] of the insulation - in any other insulation systems Kzapasa ranges from 1.5 to 2 [o.e.] and with this type of insulation it is 2.5: 3 [o.e.];

- strong decrease of the partial discharges - 2 to 3 times;

- strong decrease of the values of the dielectric constant - tgb - up to 5 times;

- complete dust resistance;

- full moisture resistance;

- resistance to chemical influences;

- high mechanical stability and reliability.

Improving energy performance makes it possible to produce rotating electrical machines with increased energy efficiency.

The improvement of the energy indicators gives an opportunity for repair and rehabilitation of existing rotating electric machines with increase of the energy indicators up to 20%, and hence increased energy efficiency of the newly repaired machine.

Claims (11)

1. Half-section with VPI insulation system for medium and high voltage electric machine, consisting of: cut and cut elementary profile copper conductors (1) parallel arranged one above the other and next to each other, woven in two parallel rows, constituting the half-section, each conductor having conductor insulation (2), vertical separator (3) between the two rows of conductors, transposition separator (4) on the thin part of the half-section, when passing a wire from one to the other row, as on the half-section are applied basic insulation (6), conducting corona protection tape (7), semi-conducting corona protection tape (8) in the curved parts, protective foam strip (9) in the front parts, and the half-section is impregnated with impregnation varnish, characterized in that: as a material for the vertical (3) and transposition (4) separators an insulating material with composition and relative weight in g / m ^{2 is used.} : highly absorbent material based on PET wool with a thickness of 02 mm and a relative weight of 50-1-348 g / m ² , the PET wool in this composition has a density of 4:10 g / m ² and an epoxy anchor accelerator wire system with a density of 500-4 100 mg / m ² ; the main insulation (6) is multilayer with the same composition and structure of the layers, each layer is composed of two-layer or three-layer tape material and the main insulation (6) is composed of a carrier on which mica is applied, which is glued to the carrier with resin or silicone, as in the composition of the basic insulation (6) there are also accelerators for polymerization of the impregnation varnish; the conductive corona protection strip (7) is made of polyester wadding impregnated with carbon-containing varnish, the polyester wadding being 0.100.15 mm thick and weighing 50 121 g / m ² ; the semiconducting corona protection tape (8) is a polyester fabric impregnated with a silicone-carbon mixture in B stage or a special resin BG 67276 Bl with a total thickness of 0.1 KO, 32 mm and a weight of 225 = 395 g / m ² ; the protective porous strip (9) is composed of mixed polyester resin-impregnated glass fiber tape mixed with an accelerator with data: thickness 0.08 = 0.10 mm, total density 77-95 g / m ² , glass polyester fibers 22 = 28 g / m ² , PET film 25 = 29 g / m ² , resin 30- ^ 38 g / m ² , accelerator 250 = 450 mg / m ² . 2. Half-section with VPI insulation system for medium and high voltage electric machine, consisting of: cut and cut elementary profile copper conductors (1) parallel arranged one above the other and next to each other, woven in two parallel rows, constituting the half-section, each conductor having conductor insulation (2), vertical separator (3) between the two rows of conductors, transposition separator (4) on the thin part of the half-section, when passing a wire from one to the other row, transposition filler (5) in the upper and lower part of the half-section, which is located at both ends perpendicularly and above the vertical separator (3) and parallel and above the transposition separator (4), with basic insulation (6), conductive corona protection tape (7), semi-conductive corona protection tape (8) in the curved parts, protective porous tape (9) in the front parts applied on the half-section and the half-section impregnated with impregnation varnish, characterized in that: the vertical separator (3) is an osmotic material with a thickness of 1 = 1.2 mm and a weight of 768 = 938 g / m ² , including double-sided glued pressed insulating paper with a thickness of 0.25 mm and weight 230 = 264 g / m ² , fiberglass 108 = 132 g / m ² and resin 435 = 535 g / m ² ; the transposition separator (4) has a composition and a relative weight in g / m ² : a mechanically stable resin material with a thickness of 0,8 = 1,3 mm and a weight of 715 = 894 g / m ² including epoxy fiberglass with a thickness of 0,13 = 0.20 mm and weight 118 = 262 g / m ² , glass mat weighing 108 = 132 g / m ² and resin weighing 493 = 600 g / m ² ; the transposition filler (5) is a material with composition and relative weight in g / m ² : resinized mica paper with a thickness of 0.2 = 3.0 mm and weight 365 = 5607g / m ² , including respectively mica paper 230 ^ 3312 g / m ² and resin 135 = 2295 g / m ² ; the main insulation (6) is multilayer with the same composition and structure of the layers, each layer is composed of two-layer or three-layer tape material and the main insulation (6) is composed of a carrier on which mica is applied, which is glued to the carrier with resin or silicone, as in the composition of the basic insulation (6) there are also accelerators for polymerization of the impregnation varnish; the conductive corona protection strip (7) is made of polyester wadding impregnated with carbon-containing varnish, the polyester wadding being 0.10 ± 0.15 mm thick and weighing 50 = 121 g / m ² ; the semiconducting corona protection tape (8) is a polyester fabric impregnated with a B-stage silicone-carbon mixture or a special resin with a total thickness of 0.11 = 0.32 mm and a weight of 225 = 395 g / m ² ; the protective porous strip (9) is composed of a mixed polyester fiberglass strip impregnated with a resin mixed with an accelerator with data: thickness 0.08 = 0.10 mm, total density 77 = 95 g / m ² , glass polyester fibers 22 = 28 g / m ² , PET film 25 = 29 g / m ² , resin 30 = 38 g / m ² , accelerator 250 = 450 mg / m ² . Semi-section with VPI insulation system for medium and high voltage electrical machine according to claim 1 or 2, characterized in that: the main insulation (6) is a material with composition and relative weight in g / m ² : absorbent mica paper of non-calcined mica coated with a carrier layer of PET wool impregnated with an polymerization accelerator of the impregnation varnish, with a thickness of 0.11 = 0.18 mm and a density of 191 = 245 g / m ² , a layer of PET wool with a thickness of 0.03 mm and a density 40 = 44 g / m ² , resin 4 = 12 g / m ² , polymerization accelerator 300 = 500 mg / m ² . Semi-section with VPI insulation system for medium and high voltage electric machine according to claim 1 or 2, characterized in that: the main insulation (6) is a material with composition and relative weight in g / m ² : absorbent mica paper of uncalcified mica coated with a carrier layer BG 67276 Bl fiberglass impregnated with polymerisation accelerator of the impregnation varnish, with a thickness of 0.11 + -0.20 mm and a density of 181 ^ 322 g / m ² , mica paper with a density of 145 + -270 g / m ² , fiberglass with thickness 0.04 mm and density 23 + -26 g / m ² , resin with density 14 + -27 g / m ² , polymerization accelerator 300 + -700 mg / m ² . Half-section with VPI insulation system for medium and high voltage electric machine according to claim 1 or 2, characterized in that: the carrier at the main insulation (6) is one of the materials: fiberglass, PET - film, Kapton or PET - fleece. 6. Stator multi-winding section with VP1 insulation system for medium and high voltage electrical machine, consisting of: insulated elementary profile copper conductors (1) with rectangular cross section, the number of connected in parallel elementary copper conductors (1) being one or moreover, they are arranged parallel to each other, one on top of the other or one next to and on the other along their narrow planes and are insulated with conductive insulation (2), the main stator section being coated with: basic insulation (6), conducting corona protection tape (7), semiconducting corona protection tape (8) in the curved parts, protective porous tape (9) in the front parts and the stator section is impregnated with impregnation varnish, characterized in that: the main insulation (6) is multilayer with the same composition and structure of the layers, each layer being composed of a two-layer or three-layer strip material and the main insulation (6) consisting of a support on which mica is applied, which is glued to the carrier with resin or silicone, as in the composition of the main insulation (6) there are also accelerators for polymerization of the impregnation varnish; the conductive corona protection strip (7) is made of polyester wadding impregnated with carbon-containing varnish, the polyester wadding being 0.10 + -0.15 mm thick and weighing 50 + -121 g / m ² ; the semiconducting corona protection tape (8) is a polyester fabric impregnated with a silicone-carbon mixture in B stage or a special resin with a total thickness of 0.11 + -0.32 mm and a weight of 225 + 395 g / m ² ; the protective porous strip (9) is composed of a mixed polyester fiberglass strip impregnated with a resin mixed with an accelerator with data: thickness 0.08 ^ 0.10 mm, total density 77-95 g / m ² , glass polyester fibers 22 + - 28 g / m ² , PET film 25 + -29 g / m ² , resin 30 + -38 g / m ² , accelerator 250 +450 mg / m ² . Stator multi-winding section with VPI insulation system for electric machine for medium and high voltage according to claim 6, characterized in that: the carrier for the main insulation (6) is one of the materials: fiberglass, PET - film, Kapton or PET - fleece. A stator multi-winding section with a VPI insulation system for an electric machine for medium and high voltage, consisting of: insulated elementary profile copper conductors (1) with a rectangular cross section, the number of connected in parallel elementary copper conductors (1) being one or moreover, they are arranged parallel to each other, one on top of the other or one next to and on the other along their narrow planes and are insulated with conductive insulation (2), the main stator section being coated with: basic insulation (6), conducting corona protection strip (7), semiconducting corona protection strip (8) in the curved parts, protective porous strip (9) in the front parts and the stator section is impregnated with impregnation varnish, characterized in that: the main insulation (6) is a material with composition and relative weight in g / m ² : absorbent mica paper of uncalcified mica coated with a PET layer impregnated with an polymerization accelerator of the impregnation varnish, 0.11 + -0.18 thick mm and density 191 + -245 g / m ² , layer of PET wool with a thickness of 0.03 mm and density 40 ^: 44 g / m ² , resin 4 + -12 g / m ² , polymerization accelerator 300 + -500 mg / m ² ; the conductive corona protection strip (7) is made of polyester wadding impregnated with a varnish containing carbon, such as polyester BG 67276 Bl watt is 0.10 + 0.15 mm thick and weighs 50 + 121 g / m ² ; the semiconducting corona protection tape (8) is a polyester fabric impregnated with silicone-carbon mixture in B stage or a special resin with a total thickness of 0.11 + 0.32 mm and a weight of 225 + 395 g / m ² ; the protective porous strip (9) consists of a mixed polyester glass fiber strip impregnated with resin mixed with an accelerator with data: thickness 0.08 + 0.10 mm, total density 77 + 95 g / m ² , glass polyester fibers 22 + 28 g / m ² , PET film 25 + 29 g / m ² , resin 30 + 38 g / m ² , accelerator 250 + 450 mg / m ² . 9. Stator multi-winding section with VP1 insulation system for medium and high voltage electrical machine, consisting of: insulated elementary profile copper conductors (1) with a rectangular cross section, the number of connected in parallel elementary copper conductors (1) being one or moreover, they are arranged parallel to each other, one on top of the other or one next to and on the other along their narrow planes and are insulated with conductive insulation (2), the main stator section being coated with: basic insulation (6), conducting corona protection strip (7), semiconducting corona protection strip (8) in the curved parts, protective porous strip (9) in the front parts and the stator section is impregnated with impregnation varnish, characterized in that: the main insulation (6) is a material with composition and relative weight in g / m ² : absorbent mica paper of non-calcined mica coated with a carrier layer of fiberglass impregnated with an polymerization accelerator of the impregnation varnish, with a thickness of 0,11 + 0,2 0 mm and density 181 + 322 g / m ² , mica paper with a density of 145 + 270 g / m ² , fiberglass with a thickness of 0.04 mm and a density of 23 + 26 g / m ² , resin with a density of 14 + 27 g / m ² , polymerization accelerator 300 + 700 mg / m ² ; the conductive corona protection strip (7) is made of polyester wadding impregnated with carbon-containing varnish, the polyester wadding being 0.10 + 0.15 mm thick and weighing 50 + 121 g / m ² ; the semiconducting corona protection tape (8) is a polyester fabric impregnated with a B-stage silicone-carbon mixture or a special resin with a total thickness of 0.11 + 0.32 mm and a weight of 225 + 395 g / m ² ; the protective porous strip (9) consists of a mixed polyester glass fiber strip impregnated with resin mixed with an accelerator with data: thickness 0.08 + 0.10 mm, total density 77 + 95 g / m ² , glass polyester fibers 22 + 28 g / m ² , PET film 25 + 29 g / m ² , resin 30 + 38 g / m ² , accelerator 250 + 450 mg / m ² . A method of manufacturing a half-section with a VP1 insulation system according to claims 1-5, comprising: placing the half-section in a vacuum-pressurized hermetic impregnation chamber, in which: heating and complete tempering of the half-section in the working volume of the chamber is performed; vacuuming the working volume through a coarse vacuum until a fine vacuum is reached to draw moisture, air inclusions and other volatile substances from the half-section insulation system; filling the half-section with impregnating resin by applying pressure until reaching 5 + 7 bar; creating a pressure of 5 + 7 bar on the resin in the airtight chamber in order to completely soak into the insulation system; emptying the impregnation chamber of the impregnating resin by pumping; firing of the half-section in a furnace for polymerization of the resin-impregnated insulation system from liquid phase to solid glassy consistency, characterized in that the method also includes: heating the half-section for hardening the conductive corona protection strip (7) and the semiconducting corona protection strip 8 before placing the section in the vacuum-pressurized hermetic impregnation chamber; and in the vacuum-pressurized hermetic impregnation chamber: pouring with impregnating resin by suction into the impregnation chamber from the vacuum before applying the pressure; and emptying the impregnation chamber of an impregnating resin based on the elevated pressure to zero the pressure before applying the pumping. A method of manufacturing stator multi-winding sections with a VP1 insulation system according to claims 6-9, comprising: bobbing the stator by laying the stator multi-winding sections in the stator channels, reinforcing the sections to each other and in the channels and soldering the sections according to the winding scheme; placing the coiled stator in a vacuum-pressurized hermetic impregnation chamber, in which: heating and full tempering in the working volume of the chamber is performed; vacuuming the working volume through a coarse vacuum until a fine vacuum is reached to draw moisture, air inclusions and other volatile substances from the insulation system; flooding with impregnating resin by applying pressure to reach 5 ^ 7 bar; creating a pressure of 5-7 bar on the resin in the airtight chamber in order to completely soak it into the insulation system; emptying the impregnation chamber of the impregnating resin by pumping; draining; firing the stator in a furnace to polymerize the resin-impregnated insulation system from liquid phase to solid glassy consistency, characterized in that the method also includes: heating the insulated stator multi-winding sections to harden the conductive corona protection strip (7) and the semiconductor strip (8) before the stator bobbin; and in the vacuum-pressurized hermetic impregnation chamber: pouring with impregnating resin by suction into the impregnation chamber from the vacuum before applying the pressure; and emptying the impregnation chamber of an impregnating resin based on the elevated pressure to zero the pressure before applying the pumping.