JP2020041804A - Insulation life test method and insulation test body - Google Patents

Abstract

To enable an insulation life property to be simply evaluated.SOLUTION: An insulation life test method comprises: a preparation step (S02) of preparing an insulation test body which has a stack obtained by stacking a main insulation layer of an inorganic material and a polymer compound layer of an organic material and has an application side electrode and a ground side electrode which are inserted into the stack such that respective ends of the electrodes are spaced apart from each other, and constituting a test device; and a voltage application step (S03) of applying a voltage to the stack in a direction along the main insulation layer. In the preparation step (S02), the stack stacked to an extent capable of observing the inner state is used. The insulation life test method may further comprise an observation step of observing a situation of progression of an electrical tree in the insulation test body after the voltage application step.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an insulation life test method and an insulation test body.

  In general, in order to evaluate the insulation life of a rotating electric machine, an actual coil or a simulated coil equivalent thereto is manufactured and evaluated (see Document 1). In the evaluation of the insulation life using an actual coil, a long power application time is required, and it takes, for example, about 5000 hours to obtain a result. In addition, since a defect is included in the production of the coil, the time until destruction varies greatly, and a certain number of samples are required for evaluation. For this reason, evaluating the insulation life of various materials by changing the material used or developing a new insulating material involves a large cost and labor. For this reason, a method is desired in which the evaluation of the stage finally applied to the actual machine is performed using the actual machine coil, and the insulation life characteristics can be easily evaluated in the stage of screening candidate materials before that. However, it has not been developed.

  In order to evaluate the insulation life characteristics, it is necessary to simulate the state of insulation deterioration equivalent to that of the actual coil. The insulation of the rotating electrical machine is made of wire insulation and insulation between wires (inter-turn insulation), mica tape made of inorganic mica in a tape shape, main insulation wound around wires, and coil from the main insulation. It is mainly composed of a semiconductive layer wound for the purpose of relaxing the electric field at the end and an electric field relaxing layer. Finally, for example, in the case of a vacuum pressurization system, these are completed by impregnating / curing them with an impregnating resin. Here, the insulation life of the main insulation is considered. Deterioration of insulation of the main insulation is caused by partial discharges generated from the vicinity of wire insulation or turn insulation, or from places where electric fields are concentrated or defects, such as minute voids (voids) in the insulating layer. Occurs. The generated electrical tree progresses, eventually leading to dielectric breakdown. In the coil main insulation, the electrical tree is said to extend between the layers of the mica tape (the portion impregnated with the epoxy resin) (see Document 2). That is, if a sample that simulates the deterioration state in which the electrical tree develops between the mica tapes can be manufactured, the insulation life evaluation of the main insulation using the actual coil can be performed simply and in a short time.

JP-A-63-156559 JP-A-63-21472

  As described above, the evaluation of the insulation life characteristics using the actual coil is time-consuming and costly, and is not suitable for screening an appropriate material from various types of materials. Desired.

  Therefore, an object of the present invention is to make it possible to easily evaluate the insulation life characteristics.

  In order to achieve the above-described object, an insulation life test method according to the present invention includes a laminate in which a main insulating layer made of an inorganic material and a polymer compound layer made of an organic material are laminated, Preparing an insulation test body having an application-side electrode and a ground-side electrode inserted so as to have an interval, a preparation step of configuring a test apparatus, and applying a voltage to the laminate in a direction along the main insulation layer. And applying a voltage.

  In addition, the insulation test body according to the present invention has a laminate in which at least one main insulating layer made of an inorganic material and at least one polymer compound layer made of an organic material are laminated, and a surface where the main insulating layer spreads. An application-side electrode inserted in parallel at the first end of one polymer compound layer, and one of the application-side electrodes inserted from the second end of the polymer compound layer opposite to the first end And a ground-side electrode inserted at a predetermined interval between the end portion and the tip end portion, and the laminated body is laminated so that the internal state can be observed from the outside. It is characterized by having been done.

  According to the present invention, the insulation life characteristics can be easily evaluated.

It is a flow figure showing the procedure of the insulation life test method concerning a 1st embodiment of the present invention. It is a partial perspective view near the end of the stator as an example using an insulator which is an object of an insulation life test method concerning a 1st embodiment of the present invention. 1 is a cross-sectional view showing a configuration of a laminated conductor of a stator winding as an example using an insulator which is an object of an insulation life test method according to a first embodiment of the present invention. It is a longitudinal section showing the composition of the main insulating tape as an example using the insulator used for the insulation life test method concerning a 1st embodiment of the present invention. FIG. 2 is a partial longitudinal sectional view showing a configuration of main insulation of a stator winding as an example using an insulator which is an object of an insulation life test method according to the first embodiment of the present invention. FIG. 8 is a cross-sectional view taken along the line VI-VI of FIG. 7 illustrating a configuration of the insulation test piece according to the first embodiment of the present invention. FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6 illustrating a configuration of an insulation test piece according to the first embodiment of the present invention. It is a longitudinal section showing the composition of the test device used for the insulation life test method concerning a 1st embodiment of the present invention. 5 is a graph showing an example of a characteristic curve obtained by the insulation life test method according to the first embodiment of the present invention. It is a flow figure showing the procedure of the insulation life test method concerning a 2nd embodiment of the present invention. FIG. 13 is a cross-sectional view taken along line XI-XI of FIG. 12 illustrating a configuration of an insulation test piece according to a second embodiment of the present invention. FIG. 12 is a cross-sectional view taken along line XII-XII of FIG. 11 illustrating a configuration of an insulation test piece according to a second embodiment of the present invention. It is a perspective view showing the composition of the test device used for the insulation life test method concerning a 2nd embodiment of the present invention.

  Hereinafter, an insulation life test method and an insulation test body according to an embodiment of the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by the same reference numerals, and redundant description will be omitted.

[First Embodiment]
FIG. 1 is a flowchart showing the procedure of the insulation life test method according to the first embodiment of the present invention. The insulation life test reproduces the progress of the electrical tree in a situation where a voltage is applied to the insulation test specimen and reproduces the dielectric breakdown of the insulation test specimen. Also, a desirable insulating material is selected based on the characteristics.

  In the insulation life test method, first, an insulation material to be tested is selected (step S01). That is, an insulating material which is being considered for use in an actual machine or an insulating material which is to be used but whose insulating characteristics are to be grasped in detail is selected.

  FIG. 2 is a partial perspective view of the vicinity of an end of a stator as an example using an insulator which is an object of the insulation life test method according to the first embodiment of the present invention. The stator 10 includes a stator core 11 having a plurality of electromagnetic steel plates 11a stacked in the rotation axis direction of a rotor shaft of a rotor (not shown), and a plurality of stator windings 12.

  The stator winding 12 is provided on a laminated conductor 13 having a plurality of bundled conductors 13 a (FIG. 3), a main insulation 17 around which a main insulation tape 20 is wound, and an outside of the main insulation 17. And a semiconductive layer 19 provided on the outside thereof.

  A plurality of stator slots 11b are formed radially inward of the stator core 11 so as to penetrate in the axial direction at intervals in the circumferential direction. As described above, the laminated conductor 13 subjected to the insulation treatment on the outside penetrates through the inside of each stator slot 11b in the axial direction. A spacer 16 holds a gap between two laminated conductors 13 housed in the same stator slot 11b and radially adjacent to each other.

  Further, a wedge 15 is provided radially inside the laminated conductor 13 of each stator slot 11b to prevent the laminated conductor 13 from protruding from the radially inner surface of the stator core 11. Spacers are provided radially inside the wedges 15, between the stator windings 12 radially adjacent to each other, and radially inside the stator windings 12 radially inward, for gap adjustment and protection of the insulating portion. 16 are provided.

  FIG. 3 is a cross-sectional view showing the configuration of the laminated conductor of the stator winding. In the laminated conductor 13, seven conductors 13a are laminated in the radial direction, and are arranged in two rows in the circumferential direction. For insulation between the conductors 13a, each conductor 13a is provided with a turn insulation 14 on the outside. The number of the conductors 13a constituting the laminated conductor 13 is not limited to 14, and may be another number.

  A plurality of layers of main insulation 17 are provided outside the laminated conductor 13. FIG. 3 shows an example in which five layers of main insulation 17 are provided, but the present invention is not limited to this. For example, one layer may be used, or a plurality of layers five or more times may be used. The number of layers may be set based on the potential difference applied to the insulating portion, the withstand voltage performance of the insulating tape of the main insulation 17, and the like.

  FIG. 4 is a longitudinal sectional view showing the configuration of the main insulating tape. The main insulating tape 20 has a main insulating layer 21 and a fiber reinforced portion 22 facing each other, and a high-molecular polymer 23 for joining them.

  The main insulating layer 21 is a portion that basically has an insulating function. Further, the fiber reinforced portion 22 is a portion having a function of securing the strength as the main insulating tape 20 by supporting the main insulating layer 21 along the main insulating layer 21. The bonding high polymer 23 penetrates into the fiber reinforced portion 22 and bonds the fiber reinforced portion 22 to the main insulating layer 21.

  Here, the material of the main insulating layer 21 is, for example, an inorganic material obtained by making powder such as unfired mica or fired mica into a paper shape. The material of the fiber reinforced portion 22 is, for example, glass fiber, and is usually woven in a mesh shape. Further, the bonding high polymer 23 is an organic material such as an epoxy resin, a polyester resin, or a silicon resin.

  The thickness of main insulating layer 21 is, for example, about 100 μm. The thickness of the fiber reinforced portion 22 is thinner, for example, about 30 μm. In FIG. 4, the fiber reinforced portion 22, the bonding polymer 23 and the main insulating layer 21 are illustrated as constituent parts of the main insulating tape 20, but the bonding polymer 23 is immersed in the fiber reinforced portion 22. In addition, it has a role of joining the main insulating layer 21 and the fiber reinforced portion 22. For this reason, the thickness of only the portion of the joining high-molecular polymer 23 is scarcely present, and the main insulating layer 21 and the fiber reinforced portion 22 are usually almost in contact with each other.

  The main insulating tape 20 is wound with the main insulating layer 21 side facing the object to be insulated and the fiber reinforced portion 22 facing outward.

  FIG. 5 is a partial longitudinal sectional view showing a configuration of main insulation of a stator winding as an example using an insulator which is an object of the insulation life test method according to the first embodiment of the present invention. FIG. 5 shows only a part of the vicinity of the surface of one conductor 13a constituting the laminated conductor 13. Turn insulation 14 is provided on the surface of the conductor 13a.

  A main insulation 17 is provided outside the turn insulation 14. Specifically, the main insulation 17 is formed by winding the main insulation tape 20 around the surface of the conductor 13a on which the turn insulation 14 has been applied, and further impregnating the conductor 13a with a polymer.

  FIG. 5 shows an example in which winding is performed twice by the half-wrap method. That is, in each of the first winding and the second winding, the tape is wound while overlapping by half the width of the tape. In other words, winding is performed while moving the winding portion in the direction of the white arrow in the figure while shifting the tape by half the width of the tape. Therefore, in each winding, the main insulating layer 21 overlaps by half in the width direction.

  In the thickness direction of the main insulation 17, inside and outside of the main insulation layer 21, a polymer section 25 after impregnation is formed. The polymer section 25 after impregnation is composed of the polymer section 23 for bonding existing inside and outside the fiber reinforced section 22 (not shown in FIG. 5) and the polymer section that has entered from the outside in the impregnation step. Are formed as a mixture.

  An arrow curve T in FIG. 5 simulates the progress of the electric tree. As shown in FIG. 5, the electric tree does not penetrate the main insulating layer 21, but extends along the main insulating layer 21 outside the main insulating layer 21, that is, inside the polymer section 25 after impregnation. I do. The fiber reinforced portion 22 has, for example, a mesh structure and is a portion that does not hinder the progress of the electric tree. In the progress of the electric tree, the post-impregnated high-molecular polymer portion 25 including the inside of the stitch structure is important. Therefore, the illustration of the fiber reinforced portion 22 is omitted as described above.

  Macroscopically, the direction of the electric field is the thickness direction of the main insulation 17, but, for example, as shown in part A of FIG. Present, the electrical tree extends along the main insulating layer 21.

  Next, the insulation test body 100 (FIG. 6) is prepared, and the test apparatus 150 (FIG. 8) is configured (Step S02).

  FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 7 showing a configuration of the insulation test body according to the first embodiment of the present invention, and FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. It is.

  The insulation test body 100 has a laminate 110, a ground electrode 120, and an application electrode 130.

  The stacked body 110 has a plurality of main insulating layers 111 and a plurality of polymer compound layers 112 which spread in a plane. The plurality of main insulating layers 111 are stacked in parallel with each other. The plurality of polymer compound layers 112 are provided between the stacked main insulating layers 111.

  The laminate 110 may be formed by stacking a plurality of pieces of the main insulating tape 20 cut into the same shape and impregnating them with a polymer compound. In this case, the fiber reinforced portion 22 filled with the polymer compound is disposed between the main insulating layers 111, and this becomes the polymer compound layer 112.

  As shown in FIGS. 6 and 7, the outer shape of the stacked body 110 is a rectangular parallelepiped by stacking the rectangular main insulating layers 111; however, the present invention is not limited to this. That is, the shape of the main insulating layer 111 to be laminated may be an ellipse or another polygon other than a rectangle, for example.

  The ground electrode 120 is attached to the end of the multilayer body 110, and all of the main insulating layer 111 and the polymer compound layer 112 are partially in contact with the ground electrode 120.

  The application-side electrode 130 is a long and flat metal plate, and the tip 131 is sharply pointed. The application-side electrode 130 is inserted into any one of the plurality of polymer compound layers 112 in parallel with the plane where the main insulating layer 111 spreads, with the sharp tip 131 first. Note that the application-side electrode 130 may be previously sandwiched between the adjacent main insulating layers 111 when the stacked body 110 is formed.

  The distance D between the tip 131 of the application-side electrode 130 and the ground-side electrode 120 is managed to have a predetermined value.

  In the above, the case of the application-side electrode 130 having the sharp tip 131 has been described as an example, but the present invention is not limited to this. For example, the tip may be a curved or flat electrode.

  FIG. 8 is a longitudinal sectional view showing a configuration of a test apparatus used for the insulation life test method according to the first embodiment of the present invention. The test apparatus 150 has three insulation test pieces 100, connection conductors 151 and 152, and a power supply 153.

  The three insulation test pieces 100 are arranged in parallel with each other. The ground electrodes 120 are electrically connected to each other by a connection conductor 151, and the connection conductor 151 is grounded. The application-side electrodes 130 are electrically connected to each other by a connection conductor 152, and the connection conductor 152 is connected to a power supply 153.

  FIG. 8 shows an example of three insulation test pieces 100, but the present invention is not limited to this. In order to observe the electrical tree at a predetermined elapsed time, the number is required in consideration of the number required for conducting a destructive investigation or the number required according to the type of the polymer compound layer 112 to be compared. Should be set. Alternatively, a plurality of test devices 150 may be prepared. In this case, the power supply 153 may be shared.

  Next, a predetermined voltage is applied between the electrodes, and an electric field is formed in a direction along the main insulating layer 111, that is, in a direction parallel to a surface where the main insulating layer 111 spreads (step S03). The voltage is, for example, a high AC voltage as a voltage between the stator winding 12 and the ground. In the evaluation for DC equipment, a voltage waveform is appropriately selected, such as applying a DC voltage or, in the case of an inverter driven rotating machine, repeatedly applying an impulse voltage.

  With the above configuration, by applying a voltage to the application-side electrode 130, an electric field is generated from the tip 131 of the application-side electrode 130 toward the ground-side electrode 120, and an electric tree is formed at the tip 131 of the application-side electrode 130. When this occurs, the development of the electrical tree is reproduced in the region having the spacing D (FIG. 7).

  Therefore, the development of the electrical tree in the insulation test body 100 simulates the development of the electrical tree in the portion A sandwiched between the adjacent main insulating layers 21 in the main insulation 17 shown in FIG. The electric tree finally reaches the electrode and causes dielectric breakdown. By measuring the time until this breakdown, the material can be screened.

  Next, the ground-side electrode 120 is removed, and the end face of the laminate 110 on the side in contact with the ground-side electrode 120 is periodically checked (step S04). At this time, it is determined whether the electric tree has penetrated the end face (step S05). If it is determined that the electric tree has not penetrated the end face (step S05 NO), the ground electrode 120 is attached again, and steps S04 and S05 are repeated.

  When it is determined that the electric tree has penetrated the end face (step S05 YES), the insulation test body 100 that has penetrated the electric tree is taken out, and the details of the electric tree are examined (step S06).

  Next, it is determined whether the inspection of all the insulation test pieces 100 has been completed (step S07). If it is not determined that the inspection of all the insulation test pieces 100 has been completed (NO in step S07), steps S03 to S07 are repeated.

  When it is determined that the inspection of all the insulation test pieces 100 has been completed (step S07 YES), the relationship between the insulation breakdown time and the insulation probability is arranged (step S08).

  Steps S04 to S06 among the above steps are not essential. That is, when the electric tree penetrates, the insulation between the connection conductor 151 and the connection conductor 152 is broken. In the test apparatus 150, although not shown, the state is monitored and recorded by a voltmeter and an ammeter. When a short circuit occurs due to dielectric breakdown, the power supply 153 automatically operates a protection device such as a breaker (not shown). Therefore, the point at which the insulation is broken can be automatically recorded and confirmed. If the dielectric breakdown occurs, it is only necessary to electrically check which of the stacked bodies 110 has caused the breakdown, and remove only that portion from the test apparatus 150. Even with such a procedure, a characteristic curve described later can be created.

  FIG. 9 is a graph showing an example of a characteristic curve obtained by the insulation life test method according to the first embodiment of the present invention. The horizontal axis represents the dielectric breakdown time (hour), and the vertical axis represents the probability of breakdown (%). The distance D between the tip 131 of the application-side electrode 130 and the ground-side electrode 120 is 3 mm, and the applied voltage is 12 kVrms.

  Black circles indicate that the polymer compound layer 112 does not contain nanofillers, white diamonds indicate that the polymer compound layer 112 contains 10 wt% nanofillers, and black squares indicate high marks. The data in the case where the molecular compound layer 112 contains 5 wt% of nanofillers is shown. The solid line A indicates the case where the polymer compound layer 112 does not include the nanofiller, the broken line B indicates the case where the polymer compound layer 112 includes 10 wt% of the nanofiller, and the dashed line C indicates the case where the polymer compound layer 112 does not include the nanofiller. 11 shows characteristic curves (Weibull Vt curves) based on the respective test results when 112 contains 5 wt% of a nanofiller.

  Next, it is determined whether the investigation of all the scheduled insulating materials has been completed (step S09). If it is not determined that the investigation of all the scheduled insulating materials has been completed (NO in step S09), steps S01 to S09 are repeated.

  If it is determined that the investigation of all the scheduled insulating materials has been completed (step S09: YES), a candidate insulating material is selected (step S10).

  In the case of the results shown in FIG. 9, when the polymer compound layer 112 contains 5 wt% of the nanofiller, the dielectric breakdown time is the longest and the insulation performance is determined to be good. The molecular compound layer 112 will be selected.

  According to the insulation life test method and the insulation test specimen according to the present embodiment, as described above, in the actual system of the main insulation 17, as shown in part A of FIG. Since an electric field is formed in a portion corresponding to a portion where the electric field strength is relatively weak, that is, in a direction along the main insulating layer 111 in the insulating test body 100, the electric tree progresses. It is a test that can accelerate more. For this reason, the electrical tree can be reproduced in a shorter time in a portion simulating the portion A of FIG. 5 which is a weak portion of the main insulation as compared with a test simulating the actual system of the main insulation 17.

  As described above, since the electrical tree that induces main insulation can be reproduced in a very short time, a candidate material can be selected from a plurality of insulating materials. That is, screening can be easily performed. Then, a full-scale test of the selected or narrowed down candidate materials may be performed, that is, an actual coil or a simulated coil equivalent to the actual coil may be prepared and executed. The burden can be greatly reduced.

  As described above, according to the insulation life test method and the insulation test body according to the present embodiment, the insulation life characteristics can be easily evaluated.

[Second embodiment]
FIG. 10 is a flowchart showing the procedure of the insulation life test method according to the second embodiment of the present invention. This embodiment is a modification of the first embodiment. Instead of the insulation test body 100 and the test apparatus 150 used in step S02 in the first embodiment, the insulation test body 200 (FIG. 11) and the test apparatus 250 ( 13) in that step S22 using FIG. 13), step S24 in place of step S04 in the first embodiment, and step S25 in place of step S05 in the first embodiment are different. Except for these, it is the same as the first embodiment. Hereinafter, points different from the first embodiment will be described.

  FIG. 11 is a cross-sectional view taken along the line XI-XI of FIG. 12 showing a configuration of the insulation test body according to the second embodiment of the present invention, and FIG. 12 is a cross-sectional view taken along the line XII-XII of FIG. It is. The insulation test body 200 has a laminate 210, a ground electrode 220, and an application electrode 230.

  The stacked body 210 includes a main insulating layer 211 and a polymer compound layer 212 which are spread two-dimensionally. The main insulating layer 211 may have two layers. Alternatively, two or three or more pieces of the main insulating tape 20 cut out into the same shape may be stacked on each other and impregnated with a polymer compound to form the laminate 210.

  Further, as in the first embodiment, the shape of the main insulating layer 211 may be a shape other than a rectangle.

  The ground-side electrode 220 has a long plate shape, and is inserted into the polymer compound layer 212 from an end of the polymer compound layer 212 in parallel with a plane where the main insulating layer 211 extends.

  The application side electrode 230 has a long plate shape and a tip 231 is sharply pointed. The application-side electrode 230 is inserted into the polymer compound layer 112 in which the ground-side electrode 220 is inserted, with the sharp tip 231 first, in parallel with the plane where the main insulating layer 211 extends.

  For the application-side electrode 230 and the ground-side electrode 220, for example, a metal foil such as aluminum can be used.

  In addition, although the case where the application-side electrode 230 has the sharp tip 231 is shown as an example, the invention is not limited to this. For example, the tip may be a curved or flat electrode.

  The application-side electrode 230 and the ground-side electrode 220 are arranged in a line in the same direction, and a distance D (FIG. 7) between the tip 231 of the application-side electrode 230 and the end of the ground-side electrode 220 is a predetermined value. It is managed to be.

  In the stacked body 210, the number of stacked main insulating layers 211 is limited. As a result, as described later, light or X-rays pass through the stacked body 210, and the electric tree formed in the polymer compound layer 212 can be observed from the outside.

  FIG. 13 is a perspective view illustrating a configuration of a test apparatus used in the insulation life test method according to the second embodiment of the present invention. The test apparatus 250 includes an insulation test body 200, a power supply 253, a light source 254, and an optical microscope 255.

  The application-side electrode 230 of the insulation test body 200 is connected to a power supply 253 via a connection conductor 252. The power supply 253 is, for example, a power supply capable of applying a repetitive impulse voltage that is a high AC voltage as a voltage between the stator winding 12 and the ground. The ground electrode 220 is grounded via the connection conductor 251.

  In particular, the light source 254 irradiates light in the thickness direction of the multilayer body 210 to a region between the tip 231 of the application-side electrode 230 and the end of the ground-side electrode 220.

  The optical microscope 255 receives the transmission of the light emitted from the light source 254, focuses on an area between the tip 231 of the application-side electrode 230 and the end of the ground-side electrode 220, and generates an electric tree generated in this area. Is to observe the progress of the development from outside.

  The step of preparing the insulation test body 200 and the test apparatus 250 as described above corresponds to step S22, and the step of observing corresponds to step S24.

  In the first embodiment, the electric tree penetrates to the end of the polymer compound layer 112 that contacts the ground electrode 120. However, in the second embodiment, the electric tree is penetrated. The case where an arbitrary distance set between the tip 231 of the application-side electrode 230 and the ground-side electrode 220 has been reached is referred to as a case where the electrical tree has penetrated, and this determination step is performed in step S25. Corresponding.

  Note that a method using X-rays may be used instead of the optical method described above. In this case, an X-ray generator and an X-ray image intensifier can be used instead of the light source and the optical microscope to similarly observe the progress of the electric tree from the outside.

  As described above, in the second embodiment, the progress of the electric tree can be externally observed. As a result, in the past, the main insulation itself was opaque and could not be observed with an optical microscope, and the actual simulated coil could not be observed due to opacity of X-rays. It is possible to grasp the aspect of progress, such as the speed of progress, and to sort materials.

  Further, for example, when a nanofiller is present in the polymer compound layer 212, the effect of the nanofiller can be confirmed based on the aspect of the electrical tree.

[Other Embodiments]
As described above, the embodiment of the present invention has been described by taking the case of a vacuum pressure impregnation system as an example. However, the embodiment is presented as an example and is not intended to limit the scope of the invention.

  Furthermore, these embodiments can be implemented in other various forms, for example, other insulation systems such as a prepreg insulation system, and various omissions, replacements, and changes are made without departing from the gist of the invention. be able to.

  These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Stator, 11 ... Stator iron core, 11a ... Electromagnetic steel plate, 11b ... Stator slot, 12 ... Stator winding, 13 ... Laminated conductor, 13a ... Conductor, 14 ... Turn insulation, 15 ... Wedge, 16 ... Spacer , 17: Main insulation, 18: Electric field relaxation layer, 19: Semiconductive layer, 20: Main insulation tape, 21: Main insulation layer, 22: Fiber reinforced portion, 23: High molecular polymer for bonding, 25: High after impregnation Molecular polymer part, 100: insulation test body, 110: laminate, 111: main insulating layer, 112: polymer compound layer, 120: ground electrode, 130: application electrode, 131: tip, 150: test device, 151, 152: connection conductor, 153: power supply, 200: insulation test piece, 210: laminated body, 211: main insulation layer, 212: polymer compound layer, 220: ground electrode, 230: application electrode, 231 tip , 250 ... test equipment, 51,252 ... connecting conductor, 253 ... power supply, 254 ... light source, 255 ... optical microscope

Claims (7)

A laminated body in which a main insulating layer that is an inorganic material and a polymer compound layer that is an organic material are laminated, and an application-side electrode and a ground-side electrode that are each inserted into the laminate so that each end has an interval, Preparing an insulation test body having, and preparing a test apparatus,
A voltage applying step of applying a voltage to the laminate in a direction along the main insulating layer;
An insulation life test method comprising: In the preparatory step, using a laminated body laminated to the extent that the internal state can be observed,
After the voltage applying step, further comprising an observation step of observing the progress of the electrical tree in the insulating test body,
The method according to claim 1, wherein:   The method according to claim 2, wherein the observation is performed by an optical method or a method using X-rays. The insulation test body is prepared in a plurality, comprising the preparation step and the voltage application step for each of the insulation test body,
Based on the respective results, the method further includes a result arranging step of arranging the relationship between the breakdown time and the breakdown probability.
The insulation life test method according to any one of claims 1 to 3, wherein: Prior to the preparing step, further comprising a test target material selection step of selecting a test target insulating material,
After the result organizing step, further comprising a candidate material selecting step of selecting a candidate material,
The insulation life test method according to claim 4, wherein: A laminate in which at least one main insulating layer that is an inorganic material and at least one polymer compound layer that is an organic material are laminated;
An application-side electrode inserted at a first end of one polymer compound layer in parallel with a plane where the main insulating layer spreads;
A ground-side electrode that is inserted from a second end side of the polymer compound layer opposite to the first end and one end of which is inserted at a predetermined interval from the end. When,
With
An insulation test body, wherein the laminate is laminated so as to have a thickness such that an internal state can be observed from the outside.   The insulation test body according to claim 6, wherein the observation is performed by an optical method or a method using X-rays.

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