CN1220048A - Rotating electric machine and manufacturing method thereof - Google Patents

Abstract

The invention relates to a rotating high-voltage electrical machine, the stator winding of which comprises high-voltage cables (6) arranged in radial slots (5) in the core of the stator (1). The motor is designed to be connected directly to the power network without an intermediate transformer. According to the invention, the groove (5) is lined with a lining (12) of thermoformable material, such as aramid fibres, and has a profile that conforms to the profile of the groove (5). The liner (12) enables a high voltage cable (6) with a semiconducting outer surface (34) to be inserted in the groove without risk of damage.

Description

A kind of electric rotating machine and manufacture method thereof

The present invention first aspect relate to a kind of described in the preamble of claim 1 electric rotating machine of type, for example, synchronous machine, also have the dual-feed motor, be used for all levels of asynchronous static converter, outer utmost point motor and the motor (flow-machine) that flows synchronously.

A second aspect of the present invention relate to a kind of described in the preamble of claim 15 method of type.

Mainly plan this motor to be used for producing electric power as the generator in the power station.Plan is used for high voltage to this motor.High voltage is the voltage that surpasses 10kV thus.Be used for typical operation scope according to motor of the present invention and can be 36 to 800kV.

For the voltage in scope 6-30kV, routine has designed similar motor, and 30kV is considered to the upper limit usually.This means that generally generator will be connected on the power network through transformer, and transformer arrives the power network level to boost in voltage, promptly in about 100-400kV scope.

By using the High-Voltage Insulation electric conductor, following name, in stator winding, have and be used for transmitting a cable of similar solid insulation used in the cable of electric power, XLPE cable (polyethylene that XLPE=is crosslinked) for example, in, can increase to such level to the voltage of motor, thereby it can be directly connected on the power network and without intermediate transformer.

This notion generally requires the groove that in stator cable is placed in one dark (the more number of turn by high voltage and winding causes thicker insulation) than routine techniques.In the motor of this particular type, groove has corresponding to the degree of depth greater than half, usually greater than iron core radially extend 2/3rds.This brings mechanical natural frequency with its cooling relevant new problem interior with stator tooth (space between the stator slot).

Cable is fixed in the groove also is that a problem-cable must be inserted in the groove and its skin is not damaged.Cable stands to have the electric current 100Hz frequency, that cause the vibration tendency, and except that the manufacturing tolerance relevant with external diameter, its size also varies with temperature (being load variations) and changes.

Although when the major technique on High-Voltage Network the time electric current supply, a kind of 70kV and above notion of relating in this application, be that transformer is inserted between generator and the power network, as described in the foreword, but as possible the voltage by direct generation electrical network grade come eliminating transformer.A kind of like this generator has been described in US-4429244, US-4164672 and US-3743867.

Think and to make the coil that is used for electric rotating machine, in the voltage range of 3-25kV, have good effect.

Yet exploitation has been carried out a period of time than the effort of the generator of this higher voltage.For example can be with reference to " the electric world (Electrical World) ", on October 15th, 1932,524-525 page or leaf.This piece article has described how to arrange the generator that is designed by Parson1929 for 33kV.The generator that produces 36kV voltage at Belgian Langerbrugge has also been described.Although this article has also been inferred the possibility of further increase voltage level, these generators based on conception development cut down.This mainly is because wherein with the defective in the impregnating varnish layer insulation system of several separators use mica oil and paper.

From the report of in April, 1984 from electric power research institute (Electric Power Research Institute), EPRI, among the EL-3391, the generator notion is illustrated, for a kind of like this generator is connected on the power network, and without the purpose of intermediate transformer, these notions have realized the high voltage in the generator.This report thinks that a kind of like this scheme provides good efficiency gain and a large amount of financial benefit.Think that in 1984 might begin to develop the main cause that is directly connected to the generator on the power network is to have developed superconducting rotor by this.Winding sizable excitation capacity in superconduction field uses the air gap winding with adequate thickness to bear electric stress becomes possibility.

By according to this project think most promising notion, the design magnetic circuit notion, with a kind of winding, so-called " monolithic drum armature ", a kind ofly wherein be placed in two conductor tubes in three insulating cylinders and total is connected to a notion on the iron core without tooth and combines, think that the electric rotating machine that is used for high pressure can be directly connected to power network.This scheme means that main insulation must make enough thickly, with bearing net to net and net above earth potential.Except it needed superconducting rotor, a distinct disadvantage that proposes a plan was also to need very thick insulation, and this has increased motor size.End winding must be with oil or freon insulation and cooling, so that the highfield at place, control end.Whole motor must seal airtightly, absorbs moisture so that prevent liquid dielectric media from atmosphere.

Especially at the J.Elektrotechnika title " water and oil cooling turbogenerator TVM-300 ", on November 1st, 1970, US-4,429, in the article of 244 6-8 page or leaf " stator of generator ", and in Russian Patent specification CCCP Patent 955369, described in some trials aspect the new method of synchronous generator design.

Water of describing among the J.Elektrotechnika and oil cooling synchronous generator are intended for use the voltage up to 20kV.A kind of new insulation system of being made up of oil/paper insulation thing described in article, makes to immerse stator in the oil fully.Can be used as cooling agent spontaneously, and simultaneously as insulant.In order to prevent that the oil in the stator from leaking outside to rotor, a dielectric oil shading ring is provided at inner surface place unshakable in one's determination.Stator winding is by the conductor manufacturing that has oval hollow shape, oil and paper insulation thing are housed.The coil sides that has an insulation by means of forelock in making groove with rectangular cross section.Oil not only had been used as cooling agent in hollow conductor but also in the cavity of stator wall.Yet such cooling system need be used for being connected of oil and electricity in a large number at the end winding place.Heavy insulation causes that also the bending radius of conductor increases, and this makes the size of coil ledge increase again.

Above-mentioned US patent relates to a kind of stationary part of synchronous machine, and synchronous machine comprises the laminated sheet magnetic core that has the dovetail groove that is used for stator winding.Because the required insulation of stator winding weakens towards the inside of rotor, the rotor place is provided with the winding part that the most close neutral point is arranged, so all grooves are tapers.In addition, stationary part also comprises the dielectric oil isolating cylinder of close inner surface unshakable in one's determination, and with respect to the motor that lacks this ring, this tube can increase the excitation requirement.Stator winding is by the saturating cables manufacturing of oil immersion that has same diameter for each coil layer.All layers separate each other by means of the pad in the groove, and use forelock.Winding is characterised in that it comprises two so-called half windings that are connected in series.Insulating case inside is settled, is centered in to one of two and half windings.The conductor of stator winding by oil cooling on every side but.Have so that the shortcoming of heavy wool in system is, the danger of leakage is arranged, and may cause a large amount of cleaning works by malfunction.Insulating case is positioned at the taper terminal that a column part and are strengthened by the current-carrying layer that is partly with of groove outside, and the purpose of taper terminal is that control cable enters the electric field strength in the zone, winding place, end.

Obvious by CCCP 955369, in the another kind of the rated voltage that increases synchronous machine was attempted, oil cooled stator winding comprised conventional high-tension cable, and high-tension cable has identical size for all layers.Cable places and forms the stator slot circular, that opening radially is set corresponding to the cross-sectional area of cable and the fixing and required space of cooling agent.The different radial arrangement layers of winding are surrounded by insulated tube, and are fixed therein.The insulation spacer element is fixed on pipe in the stator slot.Because oil cooling but, also needs an inner dielectric collar here, so that oil coolant is opened with the internal air gap sealed-off.Shown structure is not represented the insulation or the stator slot of taper.That this structure demonstrates between different stator slots is very narrow, waist radially, this means the big measuring tank leakage magnetic flux that the magnetization of appreciable impact motor requires.

The present invention relates to avoid inserting stator slot during to the damage of cable outside with avoid relevant the problems referred to above of the wearing and tearing with respect to the surface of producing by vibration at run duration.Address this problem in cable winding, to use and do not have the outer field cable of mechanical protection.Cable outer layer comprises the thin semiconductor to the mechanical failure sensitivity so.

The objective of the invention is to, a kind of motor that wherein addresses this problem is provided.

Achieve this end according to the present invention, wherein provide a kind of described in the preamble of claim l the motor of type, concrete feature defines in the characteristic of this claim; And a kind of described in claim 17 method of type, be included in the concrete measure that defines in the characteristic of this claim.

By the lining in the arrangement of grooves like this, eliminate contacting between cable outer layer and the stator core part that forms cell wall.Material in the lining must be a thermoformable, thereby it can provide the complex appearance corresponding to cell wall, and keeps its shape substantially after mold pressing.Thereby can obtain the lining that contacts with cell wall, even the profile of cell wall be unique also be so, and need not also can keep lining to put in place such as the means the glue etc.

As knowing originally, the groove of electric rotating machine provides the lining of some kind, for example by US-3943392, US-3130335 and US-1974408.Yet these linings are not used in high-voltage motor, but are used for having the motor of the insulation system of another kind of type, with desired different in motor according to the present invention.Thereby such lining can not be with the outer field problem of not covering that solves a kind of like this insulation system of protection.

US-2749456 has disclosed the layout of the lining in the stator slot of original known motor.Yet the motor here is not to be used for high pressure.Motor designs in such a way, thus it can immerse in the water and move, and lining is arranged to a cable winding and opens with the water insulation.Irrelevant with the problem that the high pressure grade runs into, and purpose does not provide any mechanical protection.The material of lining is the polyvinyl chloride of extruding, and this is because formability, profile and thickness have limited the freedom of producing the lining with such characteristic, and these characteristics can make it be used for according to motor of the present invention.

A kind of motor that has all grooves constructed in accordance is favourable, and these grooves have narrow part and wide part alternately at the width that radially has variation.Wide part preferably has circular cross section to be passed through to allow cable, and is partly connected by the waist shape that constitutes narrow part.Thereby groove obtains to be similar to the profile of bicycle chain.Advantage according to lining of the present invention is noticeable especially for a kind of like this embodiment that wherein has corresponding profile.

Lining material is suitably strengthened with fiber, and the most handy aramid fibre is strengthened, thereby it can bear mechanical failure.Because it is thermoformable, so that lining can make is quite thin, near 0.1-1.0mm, best 0.2-0.5mm this means that it takies seldom useful space.

In a concrete most preferred embodiment, lining comprises elastic device.This is by manufacturing lining two-layer the realization, this two-layer flexible member that has between layer.The elasticity lining provides additional advantage: can locate cable, thereby absorb vibration.

The foregoing description and the present invention other easily embodiment be defined in the dependent claims of claim 1.

Be defined in the method in the claim 15 according to the present invention, describe lining how can be manufactured and with simple and easily mode be applied in the groove.The mold pressing lining can be produced the thin lining with complex outline in this way, and this lining is easily in the insertion groove.

This method makes in the axial insertion groove of lining energy, simplifies assembling thus.

When lining being used for have the groove of " bicycle chain profile ",, has the plate that the drum forming that replaces rise and negative area will form lining by one in order to realize the hope profile of lining.

Lining is suitably made by the sheet material that comprises aramid fibre, and sheet material has the thickness of about 0.2-0.5mm.

Above-mentioned advantageous embodiment and other advantageous embodiment according to the inventive method is defined in the dependent claims of claim 15.

Referring now to accompanying drawing, in the following description of advantageous embodiment, will explain the present invention in more detail, in the accompanying drawings:

Fig. 1 schematically is illustrated in the axial end view according to the stator sections in a kind of motor of the present invention;

Fig. 2 amplifies from the part of the details of Fig. 1 of a slot part of expression;

Fig. 3 is illustrated in another embodiment corresponding to the channel profiles in the view of Fig. 2;

Fig. 4 represents another embodiment according to lining of the present invention;

Fig. 5 shows the step of manufacturing according to lining of the present invention;

Fig. 6 shows profile according to lining of the present invention with axial cross section;

Fig. 7 is the cross section along Fig. 6 center line VII-VII; And

Fig. 8 is the cross section of the conductor that uses in motor according to the present invention.

In the signal axial view of the sector by motor stator 1 in Fig. 1, its rotor is appointed as 2.Stator is made up of the steel plate laminated core of conventionally form, and steel plate is divided into fan-shaped part, and one of them is represented in the figure.From being positioned at a radially yoke part 3 of the iron core of outermost end, a plurality of teeth 4 radially extend in rotor 2, and are separated by the groove 5 of wherein arranging stator winding.Be intended for use in the motor of high pressure at this, groove 5 has significantly greater than the common degree of depth.Cable 6 in the winding is high-tension cables, these high-tension cables substantially with the high-tension cable that is used for distribution, so-called crosslinked polyethylene (XLPE) cable can have same type.A kind of difference is, has removed common outer mechanical protection cover round such cable.Cable thereby only form by conductor, an inner semiconductor layer, an insulating barrier and an outer semiconductor layer.To the semiconductor layer of mechanical failure sensitivity thereby be exposed on the surface of cable.

In the accompanying drawings, schematically show cable 6, the conductive center part or the coil sides of the cable section that only draws.If can see like that, each groove 5 has and has the variation cross section that replaces wide part 7 and narrow part 8.Wide part 7 is circular basically, and round cable section, and the waist between these forms narrow part 8.Waist is used for each cable section of radial location.The cross section of groove is as a whole also radially inwardly narrowing down a little.This is that the voltage in the cable section is just low more because cable section is settled the closer to the inner radial of stator.Therefore can use thinner cable section here, and the outer more cable section that requires is thick more.In an example shown, use the cable of three kinds of different sizes, be arranged in 5 three kinds of corresponding size cross sections of groove 9,10,11 in.

Fig. 2 represents how a kind of lining 12 according to the present invention is arranged to the wall of adjacent channels 5.Lining is made by the aramid fibre of the calendering shaping roll extrusion, hard, for example by trade (brand) name Nomex ^TMKnown type is made down, but also can be made by glass fibre, reinforced epoxy, thermoset plastics etc. in addition.Nomex in the standard thickness of 0.17mm ^TMBe available, and the thickness that is used for lining is positioned at 0.1-1.0mm at interval.Lining material should have good heat-conducting, and can be electric insulation, perhaps manufactures groove inside ground connection is had certain resistivity.

As understanding from this figure, lining 12 has the profile corresponding to the cell wall profile, and cell wall has its narrow part 8 that replaces and wide part 7.This figure shows how cable is made up of the conductor 6a in the core, and conductor 6a is preferably formed by stranded copper thigh, by a semiconductor layer 6b, insulating barrier 6c and outer semiconductor layer 6d round.The purpose of lining is to eliminate the danger that damages outer semiconductor layer 6d.This damage may occur in during the winding of cable, when cable passes the groove insertion, the danger that is scratched by the steel plate seamed edge is arranged, but also the wearing and tearing that may cause owing to vibration and warm-up movement by cable causes.

Fig. 3 represents another embodiment of channel profiles, and the waist 8 that wherein replaces has the form of " partly " waist, because a wall of groove extends to two adjacent circular portions in section 13.Lining 12 has corresponding shape.

Fig. 4 represents another embodiment, and its middle section is corresponding to the cross section shown in Fig. 2, but formation has only the amplification detail section of a cell wall.In this embodiment, lining 12 has two-layer aramid fibre 12a, 12b.Between these layers, be furnished with a rubber layer 14.The purpose of rubber layer is flexibly to locate cable, absorbs vibration wherein thus.It is coherent that rubber layer needs not to be, but can replace with a plurality of rubber elements between the aromatic polyamides layer.Rubber layer or rubber element with 60 ℃ of glue bonds that discharge down to the aromatic polyamides layer.Some other materials with Equivalent Elasticity performance can be used for replacing rubber naturally.In addition, aromatic polyamides layer itself can be made the elasticity with equivalence.

For clarity, 12 expressions of lining among Fig. 2-4 have for cell wall with for the space of cable 6, but should be appreciated that in fact they be in contact condition.

Fig. 5 shows a step in the lining manufacturing, and this lining plans to use in the groove of the motor of certain embodiment according to the present invention.

Be cut into aramid fibre plate suitable size, that have 0.5mm thickness, for example Nomex ^TM, hot moulding between rotating cylinder 21 and molding die 22.This figure shows that mold pressing covers the lining of the total inner surface of groove, promptly all covers its wall surface.Thereby on behalf of lining, the middle part 27 of tube will be positioned at the part of the bottom of groove.When mold pressing is finished, folding or around the crooked lining of center line of rolling plates, the folding bending radius that provides corresponding to bending radius in the trench bottom.During roll extrusion, perhaps can make plate put place's attenuation therein, perhaps can provide mark to be beneficial to fold in some other mode.

Tube comprises a plurality of rollers 23, roller 23 has cylindrical profile 25 that be bonded together, concave, and molding die 22 has with spherical counter and supports the consistent shape of (counter-support) 24 and straight pin 26, spherical counter support 24 is used for the column part of lining, and the straight pin 26 between it is used for the waist of lining.Tube 21 roller 23 has different profile radiuses, and the roller that the most close mid point 27 is settled has maximum radius, and those settle farthest has a minimum radius, and those have a radius between other radiuses between being placed in.This is in order to produce the profile in the lining, and lining is corresponding to various cable dimension used in groove, as described in conjunction with Fig. 1.

When the aramid fibre plate has provided its profile and when the line place is folding therein subsequently, it will have shape shown in Figure 6 in the hot moulding process, (bottom of groove) is folding and at open top (opening of groove) in the lower end.Be shaped like this, in easy pressurized of lining energy and the axial insertion groove, it will be discharged to paste cell wall and install here.

Lining suitably provides big the extending axially of axial length than groove, thus shorter part 30,31 at one end or two ends stretch out outside the groove.What this part can be shown in 30 then is folded-out like that, to guarantee that lining can not move axially.

Fig. 8 represents the cross section according to a kind of high-tension cable 6 of the present invention.High-tension cable comprises a plurality of for example copper (Cu) and thigh part 31 that have circular cross section.These bursts part 31 is arranged in the central authorities of high-tension cable 6.Around thigh part 31 be one first semiconductor layer 32, and around first semiconductor layer 32 be an insulating barrier 33, for example XLPE insulation.Around insulating barrier 33 are one second semiconductor layers 34.Thereby notion in this application " high-tension cable " does not comprise the outer jointing jacket that surrounds this cable that is used for distribution usually.

Claims (25)

1. rotation high-voltage motor, its stator winding is included in the high-tension cable of arranging in the radial slot (5) in the iron core of stator (1) (6), it is characterized in that, at least one of described groove (5) is equipped with a lining (12) of thermoformable material, and this lining (12) has the profile corresponding to groove (5) profile in axial cross section; And winding comprises an insulation system, and this insulation system comprises at least two semiconductor layers, and every layer constitutes an equipotential surface in essence, and comprises the solid insulator between these layers.

2. motor according to claim 1, wherein at least one of all layer has and the essentially identical thermal coefficient of expansion of solid insulator.

3. motor according to claim 1 and 2 is arranged to be directly connected on the power network and without intermediate transformer.

4. according to each described motor of claim 1-3, at least one of wherein said groove (5) has the width in radial variations in the radial section that passes stator (1), has narrow part (8) and wide part (7) alternately; And wherein said lining (12) has corresponding profile.

5. motor according to claim 4, at least one of wherein said groove (5) has the profile that is similar to bicycle chain in the radial section that passes stator (1); And wherein said lining (12) has corresponding profile.

6. according to each described motor of claim 1-5, wherein said lining material is a fortifying fibre.

7. motor according to claim 6, wherein said fiber comprises aramid fibre.

8. according to each described motor of claim 1-7, wherein said lining (12) have 0.1 and 1.0mm between thickness.

9. motor according to claim 8, wherein said lining (12) have 0.17 and 0.5mm between thickness.

10. according to each described motor of claim 1-7, wherein said lining (12) comprises the elastic device (14) at least one side of groove.

11. motor according to claim 10 has the stacked form of two-layer at least described material (12a, 12b) comprising the described lining (12) of elastic device (14), arranges described flexible member (14) between all layers.

12. comprising to small part, motor according to claim 11, wherein said flexible member (14) have elastomeric material.

13. according to each described motor of claim 1-12, wherein said lining (12) is made by insulating material.

14. according to each described motor of claim 1-12, wherein said lining (12) is made by having the material that is suitable for the resistivity of semiconductor skin (34) ground connection of cable (6).

15. according to each described motor of claim 1-14, wherein said lining (12) stretches out at least one end surfaces place of stator (1); And wherein its extension (30,31) has the big width of width that is positioned at the part of groove than it in the stator circumference direction.

16. rotation high-voltage motor, its stator winding is included in the high-tension cable of arranging in the radial slot (5) in the iron core of stator (1) (6), it is characterized in that, at least one of described groove (5) is equipped with a lining (12) of thermoformable material, and this lining (12) has the profile corresponding to groove (5) profile in axial cross section; And, described winding is formed by a kind of cable, this cable comprises one or more currents, each conductor has multiply, an inner semiconductor layer provides around each conductor, the insulating barrier of a solid insulating material provides around described inner semiconductor layer, and an outer semiconductor layer provides around described insulating barrier.

17. a method that is used for making and being applied to the lining in the radial slot that has high-tension cable, high-tension cable is arranged in the stator of electric rotating machine, it is characterized in that:

-Re formable material plate is available,

-plate is cut into suitable size,

-the plate hot-die that cuts is pressed into the consistent profile of profile with the sidewall of groove,

-after this plate of hot moulding is applied in the groove.

18. method according to claim 17, wherein in being applied to groove before, the hot-die pressing plate is bent to shape corresponding to the shape of cross section of groove around line of symmetry.

19. according to claim 17 or the described method of claim 18, wherein plate hot moulding between the molding die of the roller of a concave and a corresponding concave.

20., wherein plate is cut into the size of the total inner surface that is equivalent to groove according to each described method of claim 17-19.

21. according to each described method of claim 17-20, wherein pass through to insertion wherein, and the plate that is shaped in advance be applied in the groove from stator one side shaft.

22. according to each described method of claim 17-21, wherein plate the tube of a dished portion with a plurality of circles, with the molding die of a middle convex portion with circle between hot moulding.

23. according to each described method of claim 17-22, wherein plate is cut into, the length of extending than groove a little on the axially extended direction corresponding to groove is long.

24. according to each described method of claim 17-23, wherein the sheet material that strengthens as aramid fibre is available.

25. according to each described method of claim 17-24, the plate that wherein has 0.1-0.5mm thickness is available.

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