JP2007174816A - Stator of rotating electric machine and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable stator of a rotating electric machine and its manufacturing method that prevent the loss of corona-shielding layers arising from a partial discharge that occurs to a boundary between the outermost periphery of main insulation layers to the ground and the corona-shielding layers, while securing good resin impregnating capability. <P>SOLUTION: The stator is provided with stator coils 3 comprising a main insulation layer 5 to the ground mounted in slots 2 of a stator core 1 and arranged on the outside periphery of coil conductors 4, and the corona-shielding layer 6 arranged on the outside periphery of the main insulation layer 5. The corona-shielding layer 6 has a compound tape 20 formed by integrally bonding a conductive tape 22 which is made by applying or impregnating a conductive material on an insulation base material formed with woven cloth of inorganic fibers or non-heat-shrinkable high-polymer fibers or unwoven cloth, and a mica layer 21. This compound tape 20 is wound in such a way that the conductive tape 22 comes to the outside. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a stator of a low resistance corona shield layer provided at a position corresponding to a slot of a stator core of a high-voltage rotating electric machine in a stator used in the rotating electric machine, particularly a stator coil constituting the stator. The present invention relates to an improvement and a method for manufacturing the stator.

  In general, a stator of a rotating electrical machine is configured such that a stator coil is housed in a slot of a stator core. In particular, a stator coil used in a high-voltage rotating electrical machine has a ground main insulating layer formed on the outer periphery of a coil conductor. In addition, a low resistance corona shield layer is formed on the outer periphery of the main ground insulating layer at the slot mounting location of the stator coil.

  The above-mentioned main ground insulating layer is for insulating the coil conductor from the stator core, and is conventionally formed by winding a number of mica tapes excellent in partial discharge resistance so as to partially overlap each other. . The mica tape used in this case is configured, for example, by integrally joining a reinforcing backing material to the laminated mica layer with an adhesive or the like. The backing material is made of glass fiber or a woven or non-woven fabric of polymer fiber such as polyester or polyamide.

  On the other hand, the corona shield layer described above is for preventing partial discharge due to a potential difference between the main ground insulating layer and the slot when the stator coil is mounted in the slot. The tape is wound around the insulating ground layer so as to partially overlap each other.

  In this case, the conductive tape is conventionally mixed with a resin or a powder of a conductive material such as carbon or graphite in a woven or non-woven fabric of inorganic fiber such as glass or polymer fiber such as polyester or polyamide. The coating composition is applied or impregnated, or is made of a mixed paper in which carbon fibers are mixed with polymer fibers.

  As a method of mounting such a stator coil on the stator core, conventionally, after the stator coil is housed in a slot of the stator core, the entire impregnation method in which the whole is impregnated in a thermosetting resin, There is a single impregnation method in which a stator coil alone is impregnated in a thermosetting resin in advance before the stator coil is housed in a slot of the stator core.

  The former all-impregnation method impregnates the entire stator coil including the stator core in a thermosetting resin, so it is easy to apply to a small and relatively low-voltage rotating electrical machine. In such a large size, a large facility is required for an impregnation tank, a heating device, etc., and a large amount of thermosetting resin is consumed, resulting in an increase in cost. On the other hand, in the latter simple impregnation method, only the stator coil is impregnated and cured in a thermosetting resin, and then this stator coil is accommodated in the slot of the stator core, so that the manufacturing equipment is also available. There is an advantage that it is not necessary to increase the size and the consumption of the thermosetting resin is relatively small.

  By the way, when adopting the above-described simple impregnation method, after the main land insulating layer and the corona shield layer are immersed in an impregnation tank and impregnated with a thermosetting resin, the impregnated resin is heated and cured in a drying furnace. When the stator coil is lifted from the impregnation tank, a part of the impregnation resin leaks out of the stator coil, or the viscosity of the impregnation resin decreases due to the temperature rise at the time of heat curing, and the impregnation resin Some may leak from the stator coil. As a result, voids are generated inside the ground-side insulating layer or at the boundary between the ground-side insulating layer and the corona shield layer. If air gaps exist inside the ground insulating layer or at the boundary between the ground insulating layer and the corona shield layer, discharge occurs in these air gap portions due to high voltage during operation.

  Here, even if a gap is generated inside the ground insulating layer, the influence of the partial discharge is relatively slight because the periphery is surrounded by mica tape having excellent partial discharge resistance. On the other hand, when a discharge occurs in the gap that exists at the boundary between the main earth insulating layer and the corona shield layer, conductive materials such as carbon and graphite are scattered to give the corona shield layer low resistance. As a result, the corona shield layer itself may disappear. Then, since the corona shield effect of the corona shield layer is lost, an even greater discharge is generated between the main earth insulation layer and the stator core, resulting in damage to the main earth insulation layer and eventually causing dielectric breakdown. There is a fear.

  As a countermeasure, the conventional technology uses a semiconductive tape formed by integrally bonding a laminated mica layer on one side of the polymer film substrate and a semiconductive layer on the other side. There has been proposed a method in which a corona shield layer is formed by winding a semiconductive tape around a ground insulating layer so that the semiconductive layer faces outside (for example, Patent Documents 1 and 2). reference).

  When forming a low-resistance corona shield layer using the semiconductive tape having the configuration described in Patent Documents 1 and 2, the laminated mica layer is excellent in partial discharge resistance. The impact can be reduced. In addition, since the polymer film substrate does not allow the resin to permeate, when the impregnated resin is heat-cured, a part of the impregnated resin leaks out of the stator coil, and a gap is formed at the boundary between the ground insulating layer and the corona shield layer. It is possible to reduce the occurrence of defects such as the formation of a certain extent.

JP-A-8-237916 JP 2003-259589 A

However, the configurations described in Patent Documents 1 and 2 have the following problems.
That is, since the polymer film substrate, which is a constituent material of the semiconductive tape, does not permeate the resin, the resin impregnation path from the surface of the corona shield layer is limited only to the laminated mica layer. For this reason, it is difficult to impregnate the main land insulating layer with the resin via the corona shield layer, and there is a possibility that poor impregnation may occur, and the impregnation treatment time becomes long.

  In addition, since the polymer film base material has a weak strength against scratching and tearing, there is a problem that the polymer film base material may be damaged during the manufacturing operation of the stator coil. Furthermore, in order to improve the resin impregnation property, when forming the corona shield layer, it may be possible to reduce the overlapping portion when the semiconductive tape is wound around the ground insulating layer. A gap may be generated due to a change in the winding position, and the reliability as the corona shield layer is lacking.

  Further, Patent Document 2 discloses a laminated mica insulating member on one side of a semiconductive polymer fiber material using a woven or non-woven fabric made of organic fibers such as heat-shrinkable polyester coated with a semiconductive resin. A configuration in which a corona shield layer is formed by winding a pasted corona prevention tape around a coil insulating layer is also proposed.

  When the stator coil is mounted on the stator core, when the full impregnation method is adopted, the space other than the coil in the slot is filled with the impregnating resin, so that the semiconductive polymer fiber material constituting the corona prevention tape is used. Even if it has heat shrinkability, there is no problem.

  However, when the single impregnation method is adopted, if the semiconductive polymer fiber material for constituting the corona shield layer has heat shrinkability, the cross section of the corona shield layer provided in the stator coil when heat-cured The shape tends to be elliptical as a whole. When the stator coil having such an elliptical cross section is accommodated in the slot, the outer shape of the stator coil does not conform to the inner surface shape of the slot, and the electrical and mechanical between the corona shield layer and the slot are mechanical. Insufficient contact.

  As described above, if the electrical contact between the corona shield layer and the slot is insufficient, when the potential of the corona shield layer becomes high, a discharge occurs between the stator core and the corona shield layer or ground-to-earth insulation. There is a risk of damaging the layer. Also, if the mechanical contact between the corona shield layer and the slot is insufficient, the contact area between the two will be small, and the stator coil will easily move in the slot due to electromagnetic vibration or stress at the time of sudden short-circuiting, and from the slot Causes problems such as protrusion.

  The present invention has been made to solve the above-mentioned problems, and while ensuring good resin impregnation properties, partial discharge is generated in the gap generated at the boundary between the outermost peripheral portion of the insulating layer and the corona shield layer. Take measures to prevent the corona shield layer from disappearing even if it occurs, and to ensure sufficient electrical and mechanical contact when the stator coil is attached to the stator core by the single impregnation method. Accordingly, an object of the present invention is to provide a highly reliable stator for a rotating electrical machine and a method for manufacturing the same.

  In order to achieve the above object, a stator according to the present invention is mounted on a slot of a stator core and has an insulating layer applied to the outer periphery of the coil conductor, and a corona shield layer applied to the outer periphery of the insulating layer. In the stator of a rotating electrical machine having a stator coil having the above structure, the corona shield layer is made of a conductive woven fabric or conductive non-woven fabric made of inorganic fibers or non-heat-shrinkable polymer fibers, or non-heat-shrinkable. And a mica body integrally joined to the electroconductive body, and the electroconductive body of the composite is the mica body. It is characterized by being wound on the outer layer from the body.

  The stator manufacturing method of the present invention comprises the step of forming the insulating layer on the outer periphery of the coil conductor, and the composite is formed at a location corresponding to the slot of the stator core on the outer periphery of the insulating layer. Forming a corona shield layer by winding the conductive body so that the conductive body becomes an outer layer than the mica body and the composites partially overlap each other, and configuring a stator coil; A step of impregnating and curing the resin in the stator coil; and a step of mounting the formation portion of the corona shield layer of the stator coil in the slot of the stator core after the resin is impregnated and cured. It is said.

  According to the present invention, a composite body formed by integrally joining a conductive body and a mica body is used, and the composite body is wound so that the conductive body is outside the mica body, and the corona shield layer is formed. Therefore, when the stator coil is lifted from the impregnation tank, a part of the impregnating resin leaks out of the stator coil, or the viscosity of the impregnating resin decreases due to the temperature rise at the time of heat curing. Leaks from the stator coil, and even if a gap is formed directly below the corona shield layer, the gap does not directly contact the conductive body in the vertical direction. The mica body is always present. For this reason, problems such as disappearance of the corona shield layer due to discharge do not occur, the corona shield effect can be maintained for a long period of time, and a highly reliable stator for a rotating electrical machine can be provided.

  And since the polymer film base material as described in patent document 1, 2 is not used for the composite_body | complex for comprising a corona shield layer, resin impregnation property is not impaired. For this reason, there is no possibility that the impregnation treatment time will be prolonged and impregnation failure will not occur. In addition, since there is no problem in resin impregnation, there is no need to extremely reduce the overlapping portion when the corona shield layer is wound around the insulating layer, and therefore, a gap is generated due to a slight variation in the winding position as in the conventional case. There is no fear. Furthermore, since sufficient strength against scratching and tearing can be ensured, there is little risk of damage during the production of the stator coil.

  In addition, in the present invention, when a single impregnation method is adopted, a semiconductive polymer fiber material for constituting a corona shield layer as described in Patent Document 2 has heat shrinkability. Is not used, the corona shield layer does not have an elliptical cross section. For this reason, when the stator coil is housed in the slot, sufficient electrical and mechanical contact between the corona shield layer and the slot can be obtained. As a result, the electrical contact between the two is insufficient, causing a discharge, or the contact area between the two is so small that the stator coil easily moves in the slot and protrudes from the slot. It can be surely prevented.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing a part of a stator of a rotating electrical machine according to Embodiment 1 of the present invention in a state where a stator coil is mounted in a slot of a stator core, and FIG. FIG. 3 is a cross-sectional view schematically showing an enlarged portion indicated by the symbol A in FIG. 2, and FIG. 4 is a corona shield layer of the stator coil. It is sectional drawing which shows a part of composite tape which comprises.

  In the first embodiment, a stator coil 3 is housed in a slot 2 provided in the stator core 1, and an end portion of the stator coil 3 is drawn out of the slot 2. The stator coil 3 has a coil conductor 4 in which a plurality of insulated conductors 4a are bundled, and the ground main insulating layer 5 as an insulating layer in the scope of claims on the outer periphery of the coil conductor 4 Is formed.

Further, a low-resistance corona shield layer 6 is formed on the outer periphery of the ground main insulating layer 5 at the slot mounting location of the stator coil 3. Further, a high-resistance corona shield layer 8 is formed at a portion of the stator coil 3 protruding from the slot 2 so as to cover the ground main insulating layer 5 and to be connected to the corona shield layer 6. In addition, thermosetting resin such as epoxy resin is impregnated and cured with respect to the main land insulating layer 5 and the corona shield layers 6 and 8.
Reference numeral 9 denotes a wedge for preventing the stator coil 3 from protruding from the slot 2.

  The ground main insulating layer 5 is for electrically insulating the coil conductor 4 from the stator core 1, and the mica tape 10 having excellent partial discharge resistance is partially overlapped around the coil conductor 4. It is configured to be wound many times.

  Here, the mica tape 10 has the same configuration as that of the prior art. For example, the laminated mica layer 11 formed by making mica powder and inorganic fibers such as glass, or non-heat-shrinkable polyester or polyamide are used. The reinforcing backing material 12 is made of a woven or non-woven polymer fiber, and the both 11 and 12 are integrally joined with an adhesive or the like. In this example, the ground conductor insulating layer is wound around the coil conductor 4 so that the backing material 12 is on the outer side of the laminated mica layer 11 and the mica tape 10 is wound several times so as to partially overlap each other. 5 is formed.

  On the other hand, the corona shield layer 6 is for preventing partial discharge from being generated due to a potential difference between the main ground insulating layer 5 and the slot 2 when the stator coil 3 is mounted in the slot 2. The composite tape 20 as a composite body in the claims is wound around the ground main insulating layer 5 so as to partially overlap each other.

  As shown in an enlarged view in FIG. 4, the composite tape 20 in this case is formed by bonding the assembled mica layer 21 as a mica body in the claims and the conductive tape 22 as a conductive body in the claims. It is integrally joined with an agent or the like. Here, the assembled mica layer 21 is made of mica powder. It is also possible to use a peeled mica layer instead of the laminated mica layer 21 of this example.

  In addition, the conductive tape 22 is made of, for example, carbon, graphite, iron powder on a substrate formed of inorganic fibers such as glass, or woven or non-woven fabric made of polymer fibers such as non-heat-shrinkable polyester or polyamide. It is made of a conductive material powder such as iron oxide or a material obtained by coating or impregnating a resin mixed with a fiber, or a mixture of non-heat-shrinkable polymer fibers and carbon fibers.

  The high-resistance corona shield layer 8 is for preventing discharge at the end of the low-resistance corona shield layer 6 of the stator coil 3 drawn out from the slot 2, and has a special configuration similar to the conventional one. It can be used without any restrictions.

  When manufacturing the stator coil 3 having the above configuration, first, the coil conductor 4 is manufactured by bundling a plurality of insulated wire conductors 4a. Then, the mica tape 10 is wound around the coil conductor 4 so that the backing material 12 is on the outside and the mica tape 10 is partially overlapped with each other to be wound many times (for example, 10 to 15 times). 5 is formed.

  Next, the low-resistance corona shield layer 6 is formed by winding the composite tape 20 around the portion corresponding to the slot of the stator core 1 so that the conductive tape 22 is outside and partially overlapping each other. . Further, a high resistance corona shield layer 8 is formed at the end of the stator coil 3 so as to be connected to the low resistance corona shield layer 6.

  In the first embodiment, when the stator coil 3 is attached to the stator core 1, the single impregnation method is adopted. Therefore, the stator coil 3 formed as described above is used as the impregnation tank. Then, a thermosetting resin such as epoxy resin is vacuum-pressurized and impregnated. Subsequently, the corona shield layer 6 and the earth main insulating layer 5 are sufficiently impregnated with resin, and then taken out from the impregnation tank, and then placed in a drying furnace to be heated and cured. Subsequently, the portion where the corona shield layer 6 of the stator coil 3 impregnated and cured with resin is formed is housed in the slot 2 of the stator core 1.

  As described above, conventionally, when the stator coil 3 is pulled up from the impregnation tank, a part of the resin leaks out of the stator coil 3, or the temperature of the impregnation resin rises at the time of heat curing and the viscosity decreases. It becomes easy to flow, and a part of the resin leaks from the stator coil 3. In particular, the resin impregnated in the boundary portion between the main ground insulating layer 5 and the corona shield layer 6 is likely to leak to the outside, and therefore, directly below the corona shield layer 6, that is, at the winding step portion on the outermost periphery of the mica tape 10. As a result, gaps V1 were formed, and as a result, discharge occurred in these gaps V1 due to high voltage during operation, and the corona shield layer 6 disappeared.

  On the other hand, in this Embodiment 1, the composite tape 20 formed by integrally joining the laminated mica layer 21 and the conductive tape 22 is used, and the conductive tape 22 is placed outside the composite tape 20. Since the low-resistance corona shield layer 6 is wound around the stator coil 3 when the stator coil 3 is lifted from the impregnation tank, a part of the impregnation resin leaks out of the stator coil 3 or is heated and cured. Even if the viscosity of the impregnating resin is reduced due to the temperature rise and a part of the resin leaks out of the stator coil 3 to form the gap V1 immediately below the corona shield layer 6, the gap V1 is formed in the conductive tape 22. There is no direct contact between the upper and lower sides, and the laminated mica layer 21 is always interposed between the gap V1 and the conductive tape 22. That is, since the gap V1 is sandwiched between the laminated mica layers 21 having excellent partial discharge resistance, the conductive tape 22 constituting the corona shield layer 6 even if partial discharge occurs in the gap V1. Therefore, the corona shield effect can be maintained over a long period of time. Therefore, it is possible to provide a highly reliable stator coil 3 of a rotating electrical machine.

  In addition, since the polymer film base material described in Patent Documents 1 and 2 is not used as a material for constituting the ground main insulating layer 5 or the corona shield layer 6, the resin impregnation property is impaired. There is nothing. For this reason, there is no possibility that the impregnation treatment time will be prolonged and impregnation failure will not occur. In addition, since there is no problem in the resin impregnation property, it is not necessary to extremely reduce the overlapping portion when the composite tape 20 is wound around the ground main insulating layer 5 in order to form the corona shield layer 6. Thus, there is no possibility that a gap is generated by a slight change in the winding position. Furthermore, since the composite tape 20 can ensure sufficient strength against scratching and tearing, there is little risk of damage during the manufacturing operation of the stator coil 3.

  Furthermore, in this Embodiment 1, as a conductive tape 22 for constituting the corona shield layer 6, a heat-shrinkable semiconductive polymer fiber material as described in Patent Document 2 is used as a base material. Since it is not used, the cross-sectional shape of the corona shield layer 6 can be kept substantially rectangular along the inner surface shape of the slot 2 even when the single impregnation method is adopted. For this reason, when the stator coil 3 is housed in the slot 2, sufficient electrical and mechanical contact between the corona shield layer 6 and the slot 2 can be obtained. As a result, electric discharge is generated due to insufficient electrical contact between the two and 6, and the stator coil 3 easily moves within the slot 2 due to the small contact area between the two and 6. It is possible to reliably prevent the occurrence of problems such as overhang.

Embodiment 2. FIG.
FIG. 5 is a cross-sectional view schematically showing the main part of the stator of the rotating electric machine in the second embodiment, and the same reference numerals are given to the components corresponding to those in the first embodiment shown in FIGS. Attached.

  The second embodiment is characterized by the low resistance corona shield layer 6 formed by winding the composite tape 20 with the configuration shown in the first embodiment, that is, the conductive tape 22 facing outside. The second corona shield layer 7 is formed by further winding a shield tape 30 as a conductive body so as to partially overlap each other on the outer periphery thereof.

  The shield tape 30 constituting the second corona shield layer 7 is a conductive tape having the same structure as that conventionally used for forming the corona shield layer 6, for example, an inorganic fiber such as glass. Or a non-heat-shrinkable polyester or polyamide polymer fiber woven or non-woven fabric coated with or impregnated with a conductive material powder or fiber mixed with resin, such as carbon or graphite, or It consists of a mixed paper in which non-heat-shrinkable polymer fibers are spun together with carbon fibers.

  By the way, when the corona shield layer 6 is configured by winding the composite tape 20 with the conductive tape 22 on the outer periphery of the main ground insulating layer 5 as in the first embodiment, Due to the influence of bending or the like, there is a case where the conductive tape 22 does not continuously contact the stator core 1 but contacts the stator core 1 in the length direction of the stator coil 3.

  Conventionally, as shown in FIG. 6A, the low-resistance corona shield layer 6 is formed by winding a conductive tape 15 around the ground main insulating layer 5 so as to partially overlap each other. Electrical connection is ensured at the overlapping portions of the tape 15. Therefore, the current can flow through the overlapping portion of the tape 15, and the resistance value becomes low.

  On the other hand, as shown in FIG. 6B, when the composite tape 20 is wound so as to partially overlap each other with the conductive tape 22 on the outside, the overlapping portion is assembled with the conductive tape 22. The mica layer 21 is in contact, and there is no direct contact between the conductive tapes 22.

  Even in this case, when the composite tape 20 is wound with the conductive tape 22 facing outside, the conductive tape 22 is continuous with the stator core 1 or at many points in the length direction of the stator coil 3. Sufficient electrical conductivity is obtained when they are in contact with each other, so that there is no possibility of electric discharge between the conductive tape 22 and the stator core 1.

  However, as described above, due to the influence of the bending of the stator coil 3, the conductive tape 22 does not continuously contact the stator core 1 in the length direction of the stator coil 3, but is in a state of being in contact with flying. When this occurs, since there is no contact between the conductive tapes 22 at the overlapping portions of the composite tape 20, the current flows in a spiral shape along the circumferential direction of the conductive tape 22. Therefore, there is a possibility that the resistance value becomes high.

  In this case, since the potential of each part of the conductive tape 22 is determined by the resistance value from the contact point with the stator core 1 and the partial pressure of the insulation capacitance and resistance value, the contact point with the stator core 1 At the position of the non-contact point away from the center, the potential difference between the potential of the conductive tape 22 and the stator core 1 becomes large, and there is a possibility that electric discharge occurs between the conductive tape 22 and the stator core 1. .

  On the other hand, in the second embodiment, since the second corona shield layer 7 is formed by further winding the conductive shield tape 30 around the outer periphery of the low-resistance corona shield layer 6, the composite tape 20 Is continuously in contact with the conductive shield tape 30 constituting the second corona shield layer 7 along the length direction of the stator coil 3. For this reason, an electric current can flow through the overlapping part of the electroconductive tape 22 of the composite tape 20 and the electroconductive shield tape 30 in the outer periphery. For this reason, the resistance value becomes low, and the potential difference between the stator core 1 and the second corona shield layer 7 is small.

  Further, since the second corona shield layer 7 and the corona shield layer 6 are press-molded when the stator coil 3 is manufactured, the shield tape 30 and the conductive tape 20 are cured while being in close contact, and the length of the stator coil 3 is increased. Contact continuously in the vertical direction. For this reason, as described above, the potential difference between the two 20 and 30 can be reduced. Therefore, even if there is a gap V2 between the shield tape 30 and the conductive tape 20, the ground potential is the same as that of the stator core 1, so that partial discharge is suppressed.

  Therefore, in the case of the second embodiment, not only does the conductive tape 22 constituting the composite tape 20 not disappear even if a discharge occurs in the gap V1 formed immediately below the corona shield layer 6, By providing the second corona shield layer 7, it is possible to reliably prevent the occurrence of electric discharge with the stator core 1. Therefore, the stator coil 3 having higher reliability than that of the first embodiment is provided. It becomes possible to provide.

  Since other configurations and operational effects are the same as those of the first embodiment, detailed description thereof is omitted here.

Embodiment 3 FIG.
FIG. 7 is a cross-sectional view schematically showing the main part of the stator of the rotating electric machine according to Embodiment 3, and FIG. 8 is a cross-sectional view showing a part of the composite tape constituting the corona shield layer. Components corresponding to those of the first embodiment shown in FIG.

  The feature of the third embodiment is that the low-resistance corona shield layer 6 is formed by integrating the mica tape 41 as a mica body in the claims and the conductive tape 42 as a conductive body in the claims. The composite tape 40 is wound around the composite tape 40 so that the conductive tape 41 is outside and partially overlaps each other.

  In this case, the mica tape 41 has the same configuration as that of a mica tape that is usually used to form the conventional ground-main insulating layer 5, for example, a laminated mica layer 43 formed by making mica powder, A reinforcing backing material 44 made of a woven or non-woven fabric of inorganic fibers such as glass or polymer fibers such as non-heat-shrinkable polyester or polyamide is integrally joined with an adhesive or the like. The conductive tape 42 is bonded to the non-bonding side of the laminated mica layer 43 with the backing material 44.

  On the other hand, the conductive tape 42 has the same configuration as that of the conductive tape 22 constituting the composite tape 20 of the first embodiment. For example, the conductive tape 42 is made of inorganic fibers such as glass, or non-heat-shrinkable polyester or polyamide. Coating or impregnating a base material formed of a woven or non-woven fabric made of molecular fibers with a coating of conductive material powder or fiber such as carbon, graphite, iron powder or iron oxide mixed with resin, or It consists of a mixed paper in which non-heat-shrinkable polymer fibers are spun together with carbon fibers.

  When the composite tape 40 is formed by integrally joining the normal mica tape 41 and the conductive tape 42 as in the third embodiment, the backing material 44 of the mica tape 41 has a tensile strength during the winding operation. Therefore, there is an advantage that the winding operation of the composite tape 40 can be smoothly performed without considering the tensile strength of the conductive tape 42.

  Also in the case of the third embodiment, when the composite tape 40 is wound to form the corona shield layer 6, the gap V 1 is directly formed on the conductive tape 42 even if the gap V 1 is formed immediately below the composite tape 40. Since the laminated mica layer 43 is always interposed in the vertical direction between the gap V1 and the conductive tape 42, the corona shield layer 6 is formed even if partial discharge occurs in the gap V1. The trouble that the conductive tape 42 disappears due to discharge does not occur, and the corona shield effect can be maintained over a long period of time.

  Other configurations and operational effects are the same as in the case of the first embodiment, and thus detailed description thereof is omitted here.

Embodiment 4 FIG.
FIG. 9 is a cross-sectional view schematically showing a main part of the stator of the rotating electric machine according to the fourth embodiment. Components corresponding to those in the third embodiment shown in FIGS. 7 and 8 are denoted by the same reference numerals. Is attached.

  The feature of the fourth embodiment is that the configuration shown in the third embodiment, that is, the low-resistance corona shield layer 6 formed by winding the composite tape 40 so that the conductive tape 42 is on the outside is provided. Thus, the second corona shield layer 7 is formed by winding the conductive shield tape 30 around the outer periphery so as to partially overlap each other.

  As the shield tape 30 constituting the second corona shield layer 7, one having the same configuration as the shield tape 30 forming the second corona shield layer 7 described in the second embodiment can be applied.

  As described above, when the second corona shield layer 7 is formed on the outer periphery of the corona shield layer 6, discharge occurs in the gap V <b> 1 formed immediately below the corona shield layer 6 as in the case of the second embodiment. However, the conductive tape 42 constituting the composite tape 40 does not disappear, and even if the gap V2 exists between the shield tape 30 and the conductive tape 42, the ground potential is the same as that of the stator core 1. The occurrence of partial discharge is suppressed. Therefore, it is possible to provide the stator coil 3 with higher reliability than in the case of the third embodiment.

  Other configurations and operational effects are the same as in the case of the third embodiment, and thus detailed description thereof is omitted here.

  In the second and fourth embodiments, the shield tape 30 is wound to form the second corona shield layer 7. Instead of winding the shield tape 30, the outer periphery of the corona shield layer 6 is electrically conductive. It is also possible to apply a paint containing a functional material. As a result, the conductive tapes 22 and 42 constituting the composite tapes 20 and 40 are continuously brought into contact with each other through the paint containing the conductive material along the length direction of the stator coil 3. The same operational effects as when turned can be obtained.

In the stator of the rotary electric machine of Embodiment 1 of this invention, it is a perspective view which shows a part of the state which attached the stator coil to the slot of the stator core. FIG. 4 is a cross-sectional view showing a part of the stator in a state where the stator coil is mounted in a slot of the stator core. It is sectional drawing which expands and shows typically the part shown with the code | symbol A of FIG. In Embodiment 1 of this invention, it is sectional drawing which shows a part of composite tape which comprises the corona shield layer of a stator coil. It is sectional drawing which shows typically the principal part of the stator of the rotary electric machine in Embodiment 2 of this invention. It is explanatory drawing which shows the electrical connection state of the case where a corona shield layer is formed using the composite tape of this invention, and the case where a corona shield layer is formed using the conventional conductive tape. It is sectional drawing which shows typically the principal part of the stator of the rotary electric machine in Embodiment 3 of this invention. It is sectional drawing which shows a part of composite tape which comprises the low resistance corona shield layer in Embodiment 3 of this invention. It is sectional drawing which shows typically the principal part of the stator of the rotary electric machine in Embodiment 4 of this invention.

Explanation of symbols

1 stator core, 2 slots, 3 stator coils, 4 coil conductors,
5 ground-main insulating layer, 6 corona shield layer, 7 second corona shield layer,
20 composite tape (composite), 21 assembled mica layer (mica),
22 conductive tape (conductive body), 30 shield tape (conductive body),
40 composite tape (composite), 41 mica tape (mica),
42 conductive tape (conductive body), 43 laminated mica layer, 44 backing material.

Claims (5)

In a stator of a rotating electrical machine including a stator coil that is mounted in a slot of a stator core and has an insulating layer applied to the outer periphery of the coil conductor and a corona shield layer applied to the outer periphery of the insulating layer. The corona shield layer is composed of a conductive woven fabric or conductive nonwoven fabric made of inorganic fibers or non-heat-shrinkable polymer fibers, or a conductive material made of a mixture of non-heat-shrinkable polymer fibers and carbon fibers. A rotating electric machine comprising: a composite body comprising a mica body integrally joined to the conductive body, wherein the conductive body of the composite body is wound on an outer layer from the mica body Stator. The outside of the corona shield layer is made of a conductive woven fabric or conductive nonwoven fabric made of inorganic fibers or non-heat-shrinkable polymer fibers, or a mixture of non-heat-shrinkable polymer fibers and carbon fibers. The stator of a rotating electrical machine according to claim 1, wherein a second corona shield layer made of a conductive material is provided. The stator of a rotating electrical machine according to claim 1 or 2, wherein the mica body is a laminated mica layer, or a laminated backing material integrally joined to the laminated mica layer. The stator for a rotating electrical machine according to claim 2, wherein a coating material containing a conductive material is applied to the outside of the corona shield layer instead of the second corona shield layer. 2. The method of manufacturing a stator according to claim 1, wherein the step of forming the insulating layer on the outer periphery of the coil conductor and the composite body at a position corresponding to the slot of the stator core on the outer periphery of the insulating layer. Forming a corona shield layer by winding the composite body so that the conductive body constituting the outer layer is an outer layer than the mica body and the composites partially overlap each other to form a stator coil And impregnating and curing the resin in the stator coil, and attaching the portion where the corona shield layer of the stator coil is formed to the slot of the stator core after resin impregnation and curing. A method for manufacturing a stator characterized by the above.

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