JP5857976B2 - Degradation diagnosis apparatus and degradation diagnosis method for low-voltage AC motor - Google Patents

Description

  The present invention relates to a deterioration diagnosis device and a deterioration diagnosis method for a low voltage AC motor for diagnosing a deterioration state of a coil wound around a stator core of a low voltage AC motor.

  In a low-voltage AC motor driven with a drive voltage of AC 600 V or less, a grounding abnormality can be easily detected by measuring the voltage between the ground terminals, but short-circuiting such as a rare short of a coil wound around the stator core can be detected. It is not easy to detect. In particular, the coil portion exposed from the end face of the stator core is likely to be short-circuited due to deterioration caused by contamination and dust. From such a background, conventionally, a technique for detecting a short circuit of a coil has been proposed. Specifically, Patent Document 1 describes a technique for detecting a short circuit of a coil based on an inductance component and a capacitor component obtained from between the terminals of the coil. Patent Document 2 describes a technique for generating a counter electromotive voltage in a coil using a magnet and detecting a short circuit of the coil based on a pattern of generating the counter electromotive voltage.

JP 2010-261914 A JP 2001-289923 A JP 2004-77469 A JP 2000-275168 A JP-A-9-222393

  However, according to the techniques described in Patent Documents 1 and 2, it can be detected that a short circuit has occurred in the coil, but it cannot be specified in which part of the coil the short circuit has occurred. For this reason, in the techniques described in Patent Documents 1 and 2, it is impossible to recover the insulation state of the coil by repairing the short circuit from the initial stage to the middle stage, and to prevent problems due to the short circuit of the coil. In order to solve such a problem, it is conceivable to use a method of visually identifying the short-circuited portion. However, it is possible to visually identify the short-circuited part when the progress of the short-circuiting, in which the discoloration or deterioration of the coil has progressed, is in the final stage, but the coil is greatly discolored or deteriorated from the initial to the middle stage of the short-circuiting. Therefore, it is not easy to visually identify the short circuit site.

  On the other hand, for high-voltage AC motors driven at a driving voltage higher than AC 600V, a technique is proposed in which the insulation is irradiated with monochromatic light and the degree of deterioration inside the insulation is measured based on the reflected absorbance of the insulation against monochromatic light. (See Patent Documents 3 to 5). According to this technique, it is possible to identify the short-circuited portion of the coil even if the progress of the short-circuiting is from the initial stage to the middle stage. However, in a high-voltage AC motor, the insulator is wound many times and thickened, whereas in a low-voltage AC motor, the coil is formed by an enameled wire in which a conductor is covered with an insulating film. Is as thin as several μm. For this reason, even if the techniques described in Patent Documents 3 to 5 are applied to a low-voltage AC electric motor, it is difficult to specify the short-circuit portion of the insulating film because the change in the reflection absorbance of the insulating film due to deterioration is very small. is there.

  From such a background, it has been expected to provide a technique capable of specifying a short-circuited portion of a coil included in a low-voltage AC motor regardless of the degree of progress of the short-circuit.

  The present invention has been made in view of the above, and an object of the present invention is to provide a deterioration diagnosis device and a deterioration diagnosis method for a low-voltage AC motor that can identify a short-circuit portion of a coil regardless of the degree of progress of the short-circuit. is there.

  A degradation diagnosis apparatus for a low-voltage AC motor according to the present invention is based on a gloss sensor for detecting a gloss level of a coil wound around a stator core of a low-voltage AC motor, and a gloss level of the coil detected by the gloss sensor. Diagnostic means for diagnosing the deterioration state of the coil.

  The deterioration diagnosis apparatus for a low-voltage AC motor according to the present invention is the above-described invention, wherein the gloss sensor is arranged at a position where the gloss level of the coil exposed from the axial end surface of the stator core can be detected, and the stator core And a rotation mechanism that rotates the gloss sensor in the circumferential direction of the stator core with the center axis of the rotation axis as a rotation axis.

  The deterioration diagnosis apparatus for a low-voltage AC electric motor according to the present invention is characterized in that, in the above invention, a plurality of the gloss sensors are provided, and each gloss sensor detects a gloss level at a different coil position.

  The deterioration diagnosis apparatus for a low-voltage AC motor according to the present invention is characterized in that, in the above invention, the coil is formed of an enameled wire in which a conductor is covered with an insulating film.

  The degradation diagnosis method for a low-voltage AC motor according to the present invention is based on a detection step for detecting a gloss level of a coil wound around a stator core of the low-voltage AC motor, and a gloss level of the coil detected in the detection step. And a diagnostic step of diagnosing the deterioration state of the coil.

  According to the deterioration diagnosis device and the deterioration diagnosis method for a low-voltage AC motor according to the present invention, the deterioration state of the coil is diagnosed based on the gloss level of the coil, and therefore the short-circuit portion of the coil is specified regardless of the degree of progress of the short-circuit. Can do.

FIG. 1A is a cross-sectional view in the direction of the rotation axis showing the configuration of a low-voltage AC motor to which a degradation diagnosis device and degradation diagnostic method for a low-voltage AC motor according to an embodiment of the present invention is applied. 1B is a radial cross-sectional view of the low-voltage AC motor shown in FIG. 1A. 1C is a cross-sectional view showing the configuration of the coil shown in FIGS. 1A and 1B. FIG. 2A is a view of a deterioration diagnosis device for a low-voltage AC motor according to an embodiment of the present invention as seen from the y direction. FIG. 2B is a view of a deterioration diagnosis apparatus for a low-voltage AC motor, which is an embodiment of the present invention, as viewed from the x direction. FIG. 3 is a block diagram illustrating a configuration of a deterioration diagnosis system for a low-voltage AC motor according to an embodiment of the present invention. FIG. 4 is a diagram showing an arrangement of the deterioration diagnosis device when diagnosing the deterioration state of the coil exposed from one end face of the stator core. FIG. 5 is a diagram illustrating the movement of the sensor support member when diagnosing the deterioration state of the coil exposed from the end face of the stator core. FIG. 6 is a diagram illustrating an example of the relationship between the rotation angle of the sensor support member and the gloss level detected by the gloss sensor. FIG. 7 is a diagram illustrating an example of a temporal change in the gloss level detected by the gloss sensor. FIG. 8 is a diagram showing the arrangement of the deterioration diagnosis device when diagnosing the deterioration state of the coil exposed from the other end face of the stator core.

[Configuration of low-voltage AC motor]
First, with reference to FIG. 1A to FIG. 1C, a configuration of a low-voltage AC motor to which a low-voltage AC motor deterioration diagnosis device and a deterioration diagnosis method according to an embodiment of the present invention are applied will be described. However, the configuration of the low-voltage AC motor to which the present invention is applied is not limited to the configuration shown in FIGS. 1A to 1C.

  FIG. 1A and FIG. 1B are respectively a sectional view in a rotating shaft direction and a sectional view in a radial direction of a low-voltage AC motor to which a degradation diagnosis device and degradation diagnostic method for a low-voltage AC motor according to an embodiment of the present invention are applied. 1C is a cross-sectional view showing the configuration of the coil shown in FIGS. 1A and 1B. In the following description, the rotational axis direction of the low-voltage AC motor is defined as the x direction, the direction orthogonal to the x direction in the horizontal plane is defined as the y direction, and the direction orthogonal to the x direction and the y direction is defined as the z direction (vertical direction). To do.

  As shown in FIGS. 1A and 1B, a low voltage AC motor 1 to which a deterioration diagnosis device and a deterioration diagnosis method for a low voltage AC motor according to an embodiment of the present invention is applied includes a support 2 and a central axis direction in the x direction. And a cylindrical frame 3 placed on the support base 2. An electric motor main body 10 is accommodated in the frame 3. The electric motor main body 10 is constituted by an inner rotor type electric motor, and includes a cylindrical stator core 11 and a rotor 12 arranged at a predetermined interval on an inner peripheral portion of the stator core 11.

  The stator core 11 is disposed in the frame 3 with the central axis direction as the x direction. The stator core 11 includes a plurality of teeth portions 11a and slot portions 11b formed at substantially equal intervals along the circumferential direction. After inserting the coil 11c into one of the two slot parts 11b adjacent from one end surface side of the stator core 11 to each teeth part 11a, the coil 11c is folded and adjacent from the other end surface side of the stator core 11 The coil 11c is wound by inserting the coil 11c into the other of the two slot portions 11b. As shown in FIG. 1C, the coil 11c is formed by a bundle of enamel wires in which a conductor 11c1 is covered with an insulating film 11c2 having a thickness of about several μm.

  The rotor 12 is arranged at substantially equal intervals on the outer circumferential surface of the rotor core 12a along the circumferential direction with a cylindrical rotor core 12a, a rotating shaft 12b inserted and supported in the inner peripheral portion of the rotor core 12a. And a rotor bar 12c arranged in the above. The rotor 12 is detachably disposed on the inner peripheral portion of the stator core 11.

  In the low voltage AC electric motor 1 having such a configuration, the coil 11c exposed from the end surface in the x direction of the stator core 11 is less affected by fouling and dust than the coil 11c inserted in the slot portion 11b. Easy to receive. In addition, since the insulating film 11c2 forming the coil 11c is thin, it is likely to be deteriorated by the influence of contamination and dust. Therefore, the deterioration diagnosis device for a low-voltage AC motor according to an embodiment of the present invention detects the deterioration of the coil 11c exposed from the end surface in the x direction of the stator core 11 as described below, thereby progressing the short circuit. The short-circuit part of the coil 11c is specified regardless of the degree. Hereinafter, a deterioration diagnosis device and a deterioration diagnosis method for a low-voltage AC motor according to an embodiment of the present invention will be described with reference to the drawings.

[Configuration of deterioration diagnosis device]
First, with reference to FIG. 2A, FIG. 2B, and FIG. 3, the structure of the degradation diagnosis apparatus of the low voltage | pressure AC motor which is one Embodiment of this invention is demonstrated. FIG. 2A and FIG. 2B are views of the degradation diagnosis device for a low-voltage AC motor that is an embodiment of the present invention, as seen from the y direction and the x direction, respectively. FIG. 3 is a block diagram illustrating a configuration of a deterioration diagnosis system for a low-voltage AC motor according to an embodiment of the present invention.

  As shown in FIGS. 2A and 2B, a degradation diagnosis device 20 for a low-voltage AC motor that is an embodiment of the present invention includes a pair of mounts 21a and 21b and a pair of mounts that are spaced apart in the x direction. A pair of rotation mechanisms 22a and 22b fixed on 21a and 21b, and a rotation shaft 23 rotatably supported by the pair of rotation mechanisms 22a and 22b with the x direction as the rotation axis direction are provided. A sensor support member 24 is provided on the rotation shaft 23.

  The sensor support member 24 includes a plate-like member 24a erected on the rotating shaft 23 and plate-like members 24b and 24c erected on one surface of the member 24a with a space therebetween. It is formed by a member. The sensor support member 24 is configured such that the position of the rotation shaft 23 in the central axis direction, the height of the members 24b and 24c with respect to one surface of the member 24a, and the distance between the member 24b and the member 24c can be adjusted. ing.

  A gloss sensor 25a and gloss sensors 25b and 25c for detecting the gloss level of the diagnostic object are respectively provided on one surface of the member 24a sandwiched between the member 24b and the member 24c and on the opposing surface of the member 24b and the member 24c. It is arranged. The gloss sensors 25a to 25c extract only the regular reflection light component from the reflected light from the diagnostic object, and detect the level of the extracted regular reflection light component as the gloss level.

  The number of gloss sensors provided on the sensor support member 24 is not limited to three. For example, the gloss sensor may be detachable from the members 24a to 24c, and the gloss sensor may be installed on the members 24a to 24c in accordance with the position where the gloss level is measured. Thereby, the gloss level of the diagnostic object can be detected with a smaller number. Further, by providing four or more gloss sensors, the gloss level of the diagnostic object may be detected at more positions.

  As shown in FIG. 3, amplifiers 26a, 26b, and 26c are connected to the gloss sensors 25a to 25c, respectively. The amplifiers 26a to 26c amplify the gloss level signals detected by the gloss sensors 25a to 25c, respectively, and then input the amplified signals to the coil deterioration diagnosis device 27. The coil deterioration diagnosis device 27 is configured by an information processing device such as a personal computer or a workstation. The coil deterioration diagnosis device 27 controls the operation of the rotating mechanisms 22a and 22b that rotate the rotating shaft 23, and diagnoses the deterioration state of the diagnostic object based on the gloss level signals input from the amplifiers 26a to 26c.

[Deterioration diagnosis method]
Next, with reference to FIGS. 4 to 8, a deterioration diagnosis method for a low-voltage AC motor that is an embodiment of the present invention will be described. FIG. 4 is a diagram showing an arrangement of the deterioration diagnosis device when diagnosing the deterioration state of the coil exposed from one end face of the stator core. FIG. 5 is a diagram illustrating the movement of the sensor support member when diagnosing the deterioration state of the coil exposed from the end face of the stator core. FIG. 6 is a diagram illustrating an example of the relationship between the rotation angle of the sensor support member and the gloss level detected by the gloss sensor. FIG. 7 is a diagram illustrating an example of a temporal change in the gloss level detected by the gloss sensor. FIG. 8 is a diagram showing the arrangement of the deterioration diagnosis device when diagnosing the deterioration state of the coil exposed from the other end face of the stator core.

  When diagnosing the deterioration state of the coil 11c exposed from one end surface 11d of the stator core 11, after removing the rotor 12 from the inner periphery of the stator core 11, as shown in FIG. The deterioration diagnosis device 20 is arranged so that the central axis direction of the rotating shaft 23 coincides with the central axis direction of the stator core 11. Next, as shown in FIGS. 4 and 5, the gloss sensors 25 a to 25 c are respectively arranged at predetermined intervals (for example, 10 to 10) on the side surface, the upper surface, and the lower surface of the coil 11 c exposed from one end surface 11 d of the stator core 11. The sensor support member 24 is arranged so as to face each other with a gap of about 50 mm.

  Next, as shown in FIG. 5, the coil deterioration diagnosis device 27 controls the rotation mechanisms 22a and 22b at the timing when the operation input of the operator instructing the start of the diagnosis process is detected, so that the rotation shaft 23 is moved from the initial position. Rotate 180 degrees in rotation direction A. The coil deterioration diagnosis device 27 stores the rotation angle of the rotating shaft 23 and the gloss level of the coil 11c detected by the gloss sensors 25a to 25c in association with each other.

  Next, as shown in FIG. 5, the coil deterioration diagnosis device 27 returns the rotational position of the rotating shaft 23 to the initial position, and then controls the rotating mechanisms 22a and 22b to move the rotating shaft 23 from the initial position in the rotational direction. Rotate B to 180 degrees. The coil deterioration diagnosis device 27 stores the rotation angle of the rotating shaft 23 and the gloss level of the coil 11c detected by the gloss sensors 25a to 25c in association with each other.

  In this embodiment, in order to avoid contact between the cable and the sensor support member 24, the gloss level of the coil 11c is measured over the entire circumference of the stator core 11 by being divided every 180 degrees. If there is no contact with 24, the gloss level of the coil 11c may be continuously measured over the entire circumference of the stator core 11. In the present embodiment, the gloss levels of the side surface, the upper surface, and the lower surface of the coil 11c are measured simultaneously. However, the gloss levels of the side surface, the upper surface, and the lower surface of the coil 11c may be individually measured.

  Thereby, the gloss levels of the side surface, the upper surface, and the lower surface of the coil 11c exposed from the end surface 11d of the stator core 11 are measured over the entire circumference of the stator core 11, and the side surface, the upper surface, and the lower surface of the coil 11c are measured. The relationship between the rotation angle of the rotating shaft 23 and the gloss level of the coil 11c as shown in FIG. 6 can be confirmed. Generally, as the deterioration progresses, the gloss level of the insulating film 11c2 forming the coil 11c decreases. Accordingly, based on the measurement result as shown in FIG. 6, for example, the rotation angle θ1 whose measured gloss level is equal to or less than a predetermined value is detected, and the position of the coil 11c corresponding to the rotation angle θ1 is specified, whereby the short circuit is detected. The short-circuit portion of the coil 11c can be specified regardless of the degree of progress. Further, the deterioration state of the coil 11c, that is, the progress of the short circuit can be quantitatively diagnosed based on the amount of decrease in the gloss level.

  Further, by periodically performing the diagnosis as described above and recording the average value of the gloss levels of the side surface, the upper surface, and the lower surface of the coil 11c, the side surface, the upper surface, and the coil 11c as shown in FIG. It is also possible to confirm the change with time of the gloss level of each of the lower surfaces. In the example shown in FIG. 7, when the elapsed time is T2 because the gloss level of the coil 11c is equal to or lower than the predetermined value when the elapsed day is T1, the insulating film 11c2 is repaired with an insulating varnish, for example. This shows a change in the gloss level that a short circuit failure of the coil 11c occurs when T3 is T3. By recording the change over time of the gloss level of the coil 11c, it is possible to manage the tendency of the change over time of the coil 11c.

  In the above description, the deterioration state of the coil 11c exposed from the one end surface 11d of the stator core 11 is diagnosed, but the deterioration state of the coil 11c exposed from the other end surface 11e of the stator core 11 is also determined. A similar diagnosis can be made. Specifically, in this case, the rotating shaft 23 is removed from the rotating mechanisms 22a and 22b, and the gloss sensors 25a to 25c are respectively exposed from the other end face 11e of the stator core 11 as shown in FIG. The rotating shaft 23 is installed in the rotating mechanisms 22a and 22b so as to face the side surface, the upper surface, and the lower surface. Then, by performing the same processing thereafter, the deterioration state of the coil 11c exposed from the other end surface 11e of the stator core 11 can be diagnosed.

  Although the embodiment to which the invention made by the present inventor is applied has been described above, the present invention is not limited by the description and the drawings that form a part of the disclosure of the present invention according to this embodiment. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Low voltage AC motor 2 Support stand 3 Frame 10 Electric motor main body 11 Stator iron core 11a Teeth part 11b Slot part 11c Coil 11c1 Conductor 11c2 Insulation film 12 Rotor 12a Rotor iron core 12b Rotating shaft 12c Rotor bar 20 Deterioration diagnostic device 21a, 21a frame , 22b Rotating mechanism 23 Rotating shaft 24 Sensor support member 24a, 24b, 24c Member 25a, 25b, 25c Gloss sensor 26a, 26b, 26c Amplifier 27 Coil deterioration diagnosis device

Claims (2)

A plurality of gloss sensors for detecting gloss levels at different positions of the coils wound around the stator core of the low-voltage AC motor;
Diagnostic means for diagnosing the deterioration state of the coil based on the gloss level of the coil detected by the gloss sensor;
The plurality of gloss sensors are arranged at positions where the gloss level of the coil exposed from the axial end surface of the stator core can be detected, and the circumferential axis of the stator core is set with the central axis of the stator core as a rotation axis. A rotation mechanism for rotating a plurality of gloss sensors,
The deterioration diagnosis apparatus for a low-voltage AC electric motor , wherein the coil is formed of an enameled wire in which a conductor is covered with an insulating film . A detection step of detecting gloss levels at different positions of a coil wound around the stator core of the low-voltage AC motor using a plurality of gloss sensors ;
Diagnosing a deterioration state of the coil based on the gloss level of the coil detected in the detection step,
In the detecting step, the plurality of gloss sensors are arranged at positions where the gloss level of the coil exposed from the axial end surface of the stator core can be detected, and the stator core is set with the central axis of the stator core as a rotation axis. Detecting gloss levels at different positions of the coil by rotating the plurality of gloss sensors in the circumferential direction of the coil,
A deterioration diagnosis method for a low-voltage AC electric motor , wherein the coil is formed of an enameled wire in which a conductor is covered with an insulating film .

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