JP2011155715A - Rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating electric machine capable of preventing burning loss of a corona shielding layer extending to the outside of a slot of a stator core by a simple means. <P>SOLUTION: The rotating electric machine has a structure in which a stator coil 7 operated on a voltage having a high frequency component and having a corona shielding layer 14 formed on the surface of a main insulating layer is attached in the slot 6 of the stator core via a slot liner 12, and charging current path ensuring means (13, 17, 18) for ensuring a charging current path are provided between the slot liner 12 of the stator coil 7 extending to the outside of the slot and the corona shielding layer 14. With this configuration, even partial contact occurs between the slot liner 12 and the corona shielding layer 14, a charging current flows to the flow path ensured by the charging current path ensuring means, thereby preventing the burning loss of the corona shielding layer due to concentration of charging current. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a rotating electrical machine such as an electric motor or a generator, and more particularly to a rotating electrical machine driven by a voltage having a high frequency component.

  In recent years, rotating electrical machines have been operated with a voltage having a high-frequency component in order to increase operating efficiency. Then, as disclosed in Patent Document 1, the surface of the main insulating layer of the stator coil is covered with a corona shield layer, and the stator coil is inserted into a slot formed in the stator core via a conductive slot liner. Attached and fixed by wedges.

Japanese Patent Laid-Open No. 10-174334

  In the stator coil of the rotating electrical machine described in Patent Document 1, since the contact between the corona shield layer and the slot liner in the slot of the stator core is relatively well maintained, the corona shield layer and the slot liner Are in contact with each other over almost the entire region, and as a result, the charging current proportional to the voltage change of the input voltage is distributed over the entire region.

  However, the contact between the corona shield layer of the coil end portion of the stator coil protruding from the slot end of the stator core and the slot liner may be partly due to warping or undulation of the slot liner due to the manufacturing conditions. . As a result, the charging current proportional to the voltage change of the input voltage flows in a concentrated manner at the partial contact portion between the corona shield layer and the slot liner, and there is concern that the current density is locally increased and the corona shield layer is burned out. Is done.

  An object of the present invention is to provide a rotating electrical machine capable of preventing the corona shield layer extending outside the slots of the stator core from being burned out by simple means.

  In order to achieve the above-mentioned object, the present invention is operated with a voltage having a high frequency component, and a stator coil having a corona shield layer formed on the surface of the main insulating layer is formed in a slot formed in the stator core via a slot liner. In the mounted rotating electrical machine, charging current flow path securing means for securing a flow path for charging current is provided between the slot liner of the coil end portion of the stator coil extending outside the slot and the corona shield layer.

  With the above configuration, even if the slot liner warps or swells and partially contacts with the corona shield layer, the charging current also flows through the channel secured by the charging current channel securing means. It is possible to prevent the charging current from concentrating on the contact portion and to prevent the corona shield layer from being burned out due to the concentration of the charging current.

  As described above, according to the present invention, it is possible to obtain a rotating electrical machine that can prevent the corona shield layer from burning out of the slots of the stator core by simple means.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic longitudinal side view of the vicinity of a coil end portion of a stator coil showing a first embodiment of a rotating electrical machine according to the present invention. FIG. 2 is an enlarged perspective view showing an end portion of the slot liner of FIG. 1. The equivalent figure of FIG. 1 which shows 2nd Embodiment of the rotary electric machine by this invention. FIG. 1 is a view corresponding to FIG. 1 showing a third embodiment of the rotating electrical machine according to the present invention. The equivalent figure of FIG. 1 which shows 4th Embodiment of the rotary electric machine by this invention. FIG. 1 is a view corresponding to FIG. 1 showing a fifth embodiment of the rotating electrical machine according to the present invention. FIG. 2 is a view corresponding to FIG. 2 showing a sixth embodiment of the rotating electrical machine according to the present invention. The perspective view which shows the stator of the rotary electric machine operate | moved with the voltage which has a high frequency component. The expansion perspective view which shows the coil end part of FIG.

  Hereinafter, a rotating electrical machine according to the present invention will be described based on the electric motors shown in FIGS. 1, 2, 8 and 9.

  The electric motor 1 is mainly composed of a rotor 2 and a stator 3 facing the outer diameter side of the rotor 2 with a gap.

  The rotor 2 has a rotor core supported by the rotating shaft 4 and a rotor winding attached to the rotor core.

  On the other hand, the stator 3 includes a stator core 5 formed by laminating electromagnetic thin steel plates, a plurality of slots 6 formed in the circumferential direction along the axial direction on the inner diameter side of the stator core 5, and the plurality of slots 6. A plurality of stator coils 7 mounted therein, a stator frame 8 that supports the outer diameter side of the stator core 5, and end plates (not shown) that are fixed to both axial ends of the stator frame 8 The end plate has a bearing (not shown) for supporting the rotating shaft 4.

  The stator coil 7 has a coil conductor 9 and a main insulating layer 10 formed on the surface of the coil conductor 9. The stator coil 7 is composed of a straight portion 7A mounted in the slot 6 of the stator core 5 and a coil end portion 7B projecting outside the slot 6.

  When the linear portion 7A of the stator coil 7 is mounted in the slot 6, the insulating material 11 is interposed between the stator coils 7 adjacent in the vertical direction, and the stator coils 7 adjacent in the vertical direction are grouped together. The stator coil 7 is mounted in a state of being covered with the slot liner 12 and a wedge 13 is fitted to the opening side of the slot 6 to firmly support the stator coil 7.

  A corona shield layer 14 is provided on the outer periphery of the main insulating layer 10 of the linear portion 7A mounted in the slot 6 of the stator coil 7 for the purpose of preventing corona discharge between the stator core 5 and the stator coil 7. Is covered. Further, in the coil end portion 7B of the stator coil 7, creeping discharge is generated due to electric field concentration at the end portion of the corona shield layer 14 projecting outside the slot 6, and there is a possibility that the main insulating layer 10 is deteriorated due to this. Therefore, the high resistance corona shield layer 15 is covered in a direction to cover the end of the corona shield layer 14 and away from the stator core 5.

  Such a stator coil 7 is connected to a high frequency power source 16 to drive the electric motor 1.

  By configuring as described above, in the slot 6, the main insulating layer 10, the corona shield layer 14, and the slot liner 12 are mounted in close contact with each other over almost the entire area, and are sufficiently in contact with the slot 6. Can be made. Therefore, since the charging current proportional to the voltage change of the input voltage is distributed over the entire area, there is no portion where the charging current is concentrated, and the corona shield layer 14 is burned out due to the concentration of the charging current. It does not exist in the part 7A.

  However, the contact between the corona shield layer 14 of the coil end portion 7B of the stator coil 7 projecting from the end of the slot 6 of the stator core 5 and the slot liner 12 is caused by warping or undulation of the slot liner 12 due to manufacturing conditions. For this reason, partial contact may occur. As a result, since the charging current proportional to the voltage change of the input voltage flows in a concentrated manner at the partial contact portion, there is a concern that the corona shield layer 14 may be burned out.

  Therefore, in the present embodiment, even if the slot liner 12 is warped or undulated, the partial contact between the corona shield layer 14 and the slot liner 12 protruding from the end of the slot 6 of the stator core 5 is reduced. The charging current flow path is positively formed by the charging current flow path securing means.

  As a specific example of securing the charging current channel by the charging current channel securing means, as shown in FIGS. 1 and 2, the end of the slot liner 12 is bound to a glass cloth tape, glass roving, heat shrinkable tape or the like. The slot liner 12 was brought into close contact with the corona shield layer 14 by binding with the body 17. As the electrical characteristics of the binding body 17, materials ranging from insulating properties to semiconductivity and conductivity, and materials having nonlinear resistance characteristics can be applied. Preferably, the resistivity equivalent to that of the slot liner 12 is used. A material having is desirable. For example, when a glass cloth tape is used as the binding body 17, a prepreg tape made by impregnating a glass cloth tape with a semiconductive thermosetting resin having a resistivity equivalent to that of the slot liner 12 is wound. Then, the semiconductive thermosetting resin is hardened by heat curing.

  By using such a binding body 17, the adhesion between the slot liner 12 and the corona shield layer 14 is improved, and a charging current flowing between the two, which has been concentrated due to partial contact in the past, is newly supplied. As a result, the corona shield layer 14 can be prevented from being burned out due to the concentration of the charging current.

  By the way, in this embodiment, the binding body 17 is applied only to the end portion of the slot liner 12 projecting out of the slot 6, but the binding body 17 is applied over the entire length of the slot liner 12 projecting out of the slot 6. May be.

  Furthermore, it is desirable to provide the binding body 17 on the outer periphery of the end of the slot liner 12 in the coil end portions 7B of all the stator coils 7, but in particular, the applied voltage of the input waveform to the motor and the rise of the applied voltage in the inverter control Alternatively, if the voltage change component at the time of falling is not extremely large, it may be applied only to the first or a plurality of stator coils 7 from the connection with the inverter.

  Next, a second embodiment of the rotating electrical machine according to the present invention will be described based on the coil end portion of the stator coil of the electric motor shown in FIG. 1, 2, 8, and 9 indicate the same components, and thus detailed description thereof is omitted.

  In the present embodiment, the difference from the first embodiment is the installation configuration of the binding body 18. In other words, in the present embodiment, the binding body 18 is constructed continuously in the vicinity of the end portion of the slot liner 12 that is likely to be warped and swelled, and the corona shield layer 14 facing the vicinity of the end portion of the slot liner 12. is there. Specifically, a prepreg tape in which a glass cloth tape is impregnated with a semiconductive thermosetting resin having a resistivity equivalent to that of the slot liner 12 is formed into a semi-cured state. It was wound around the corona shield layer 14, and then the semiconductive thermosetting resin was cured by heating and hardened.

  With this configuration, the adhesion between the slot liner 12 and the corona shield layer 14 is improved. As a result, as in the first embodiment, the current flow path of the charging current flowing between the two can be dispersed. Thus, it is possible to prevent the corona shield layer 14 from being burned out due to the concentration of the charging current.

  Furthermore, in the present embodiment, the gap between the end portion of the slot liner 12 and the corona shield layer 14 is scattered because the gap between the end portion of the slot liner 12 and the corona shield layer 14 is sealed by the binding body 18. Separation between the two due to entry of foreign matter can be prevented, and adhesion reliability can be improved.

  In the present embodiment, the binding body 18 is applied to the end portion of the slot liner 12 and the corona shield layer 14 in the vicinity thereof, but the binding is performed over the entire length of the slot liner 12 projecting from the slot 6 of the stator core 5. Body 18 may be applied. At that time, if there is a possibility that the binding body 18 and the stator core 5 come into contact with each other, the adhesion between the binding body 18 and the stator core 5 is prevented in advance by a release material or the like, and the binding with the stator core 5 is performed. It is desirable to prevent compressive stress and tensile stress due to thermal expansion and contraction of the coil conductor 9 between the body 18 and the body 18.

  FIG. 4 shows a coil end portion of a stator coil of an electric motor that is a third embodiment of the rotating electrical machine according to the present invention. Also in the present embodiment, the same reference numerals as those in FIGS. 1 to 3, 8, and 9 indicate the same components, and thus detailed description thereof is omitted.

  This embodiment is basically the same as the second embodiment shown in FIG. However, the mold release material 19 is provided between the corona shield layer 14 and the binding body 18 which are further improved and face the vicinity of the end portion of the slot liner 12. With this configuration, the same effects as those of the above-described embodiments can be obtained, and damage to the slot liner 12 and the corona shield layer 14 can be prevented.

  That is, when the binding body 18, the slot liner 12, and the corona shield layer 14 are firmly bonded via the semi-cured thermosetting resin of the binding body 18, when the stator coil 7 is disposed or the coil end portion 7B. There is a possibility that the slot liner 12 and the corona shield layer 14 may be damaged due to a compressive stress and a tensile stress acting between the slot liner 12 and the corona shield layer 14 during the wire connection or when the motor is operated. However, by disposing the release material 19 between the corona shield layer 14 and the binding body 18, the generated compressive stress and tensile stress can be slid and relaxed, and the slot liner 12 and the corona shield layer 14 can be relaxed. Damage can be prevented. Note that it is desirable that the resistance characteristics of the release material 19 be equal to those of the slot liner 12 and the corona shield layer 14.

  FIG. 5 shows a coil end portion of a stator coil of an electric motor that is a fourth embodiment of the rotating electrical machine according to the present invention. Also in the present embodiment, the same reference numerals as those in FIGS. 1 to 4, 8, and 9 indicate the same components, and thus detailed description thereof is omitted.

This embodiment has basically the same configuration as that of the third embodiment shown in FIG. 4, but is further improved and provided on the end portion of the slot liner 12 and the corona shield layer 14 facing the vicinity thereof. The release material 20 is provided between the binding body 18 and the lotterin 12 with which the binding body 18 contacts. With this configuration, the same effect as that of the third embodiment can be obtained. That is, with the above configuration, the binding body 18 can be compressed between the slot liner 12 and the corona shield layer 14. Even if a tensile stress is applied, the binding body 18 follows the corona shield layer 14 and is displaced relative to the slot liner 12. And damage to both can be prevented.

  Next, a fifth embodiment of the rotating electrical machine according to the present invention will be described based on the coil end portion of the stator coil of the electric motor shown in FIG. Also in this embodiment, the same reference numerals as those in FIGS. 1 to 5, 8, and 9 indicate the same components, and thus detailed description thereof is omitted.

  The difference from the above embodiments is that the end 15L of the high resistance corona shield layer 15 is extended to the end of the slot liner 12 without using a dedicated binding body for binding the end of the slot liner 12. The end portion of the slot liner 12 is tightly bound by the portion 15L.

  As described above, by causing the high resistance corona shield layer 15 to function as a binding body, the same effect as that of the first embodiment can be obtained, and the end portion of the slot liner 12 is formed of the high resistance corona shield layer 15. Since it is covered with the end portion 15L, it is possible to prevent the scattered foreign matter from entering between the end portion of the slot liner 12 and the corona shield layer 14.

  Also in this embodiment, a release material may be interposed in the contact portion between the high resistance corona shield layer 15 and the slot liner 12 to prevent damage due to compressive stress or tensile stress acting between them. .

  Next, a sixth embodiment of the rotating electrical machine according to the present invention will be described based on the coil end portion (slot liner end portion) of the stator coil of the electric motor shown in FIG. Also in the present embodiment, the same reference numerals as those in FIGS. 1 to 6, 8, and 9 indicate the same components, and thus detailed description thereof is omitted.

  In general, warping and undulation of the slot liner 12 is often observed at the end of the slot liner 12, particularly at the end of winding. Therefore, in the present embodiment, the end of the wedge 13 is extended to the end protruding from the slot 6 of the stator core 5 of the slot liner 12 or beyond, and the extended wedge 12 and stator are extended. The end of winding of the slot liner 12 is clamped with the coil 7 so that the slot liner 12 and the corona shield layer 14 are brought into close contact with each other to secure a flow path for charging current.

  With this configuration, as in the first embodiment, the adhesion between the end portion of the slot liner 12 and the corona shield layer 14 is improved and concentrated due to partial contact in the related art. The charging current flowing between the two can be distributed to the new flow path, and as a result, the corona shield layer 14 can be prevented from being burned out due to the concentration of the charging current.

  Each of the above explanations has been given by taking an electric motor as an example of a rotating electric machine, but it is needless to say that the present invention can be applied not only to an electric motor but also to a generator such as a turbine generator or a gas turbine generator.

  DESCRIPTION OF SYMBOLS 1 ... Electric motor, 2 ... Rotor, 3 ... Stator, 4 ... Rotating shaft, 5 ... Stator iron core, 6 ... Slot, 7 ... Stator coil, 7A ... Linear part, 7B ... Coil end part, 8 ... Stator Frame, 9 ... Coil conductor, 10 ... Main insulating layer, 11 ... Insulating material, 12 ... Slot liner, 13 ... Wedge, 14 ... Corona shield layer, 15 ... High resistance corona shield layer, 15L ... End, 16 ... High frequency power supply , 17, 18 ... BDSM, 19, 20 ... Release material.

Claims (11)

  In a rotating electrical machine that is operated at a voltage having a high frequency component and has a stator coil having a corona shield layer formed on the surface of the main insulating layer and mounted in a slot formed in the stator core via a slot liner, it extends outside the slot. A rotating electrical machine comprising a charging current channel securing means for securing a charging current channel between a slot liner at a coil end portion of a stator coil and a corona shield layer.   In a rotating electrical machine that is operated at a voltage having a high frequency component and has a stator coil having a corona shield layer formed on the surface of the main insulating layer and mounted in a slot formed in the stator core via a slot liner, it extends outside the slot. As a charging current channel securing means for securing a charging current channel between the slot liner at the coil end of the stator coil and the corona shield layer, a binding body for binding the outer periphery of the end of the slot liner is provided. Rotating electric machine.   The rotating electrical machine according to claim 2, wherein the binding body is provided only on an outer peripheral portion of the slot liner.   The rotating electrical machine according to claim 2, wherein the binding body is provided across the outer periphery of the slot liner and the outer periphery of the corona shield layer.   The rotating electrical machine according to claim 4, wherein a release material is interposed between the binding body and the corona shield layer.   The rotating electrical machine according to claim 4, wherein a release material is interposed between the binding body and the corona shield layer and between the binding body and the slot liner.   The rotating electrical machine according to claim 2, wherein the binding body has a resistivity equivalent to that of the corona shield layer.   The rotating electrical machine according to claim 2, wherein the binding body is an end portion of a high resistance corona shield layer that is applied to a coil end portion and binds an outer periphery of an end portion of the slot liner.   In a rotating electrical machine operated with a voltage having a high frequency component, a stator coil having a corona shield layer formed on the surface of a main insulating layer is mounted in a slot formed in the stator core via a slot liner and fixed by a wedge. A rotating electrical machine comprising a charging current channel securing means for securing a charging current channel between a slot liner and a corona shield layer at the end of winding of an overhanging slot liner.   10. The rotating electrical machine according to claim 9, wherein the charging current flow path securing means is the wedge that extends outside the slot for pinching the end of winding of the slot liner with the stator coil. .   11. The rotating electrical machine according to claim 10, wherein a release material is interposed between the extended wedge and the slot liner.

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