JP6158134B2 - Discharge position specifying device, discharge position measuring device, and discharge position specifying method - Google Patents

Description

  The present invention relates to a discharge position specifying device that specifies a position where a partial discharge is generated when a voltage is applied to a measurement object, a discharge position measuring device therefor, and a discharge position specifying method using them.

  When an electric motor is driven by an inverter, it is known that a surge voltage is generated due to high-speed switching of the inverter, which affects the insulation of the electric motor winding. Such a surge voltage is called an inverter surge, and its voltage value may reach twice or more the rated voltage of the motor. When the inverter surge is applied to the winding of the motor, there is a concern about the occurrence of partial discharge inside and outside the winding. The partial discharge causes deterioration of the enameled wire film constituting the winding. When the film deteriorates, dielectric breakdown will eventually occur. Therefore, it is necessary to design the motor so that partial discharge does not occur even if an inverter surge is applied to the winding.

  Conventionally, the insulation performance of the windings of an electric motor is evaluated based on a partial discharge test by detecting the presence or absence of partial discharge by applying a predetermined impulse voltage using a simulated sample such as an arrow pair or a motorlet, or a stator coil. It had been. Since partial discharge occurs at a weak point in insulation such as a void or an insufficient distance between conductors, the location of the weak point becomes clear if the location where the partial discharge occurs can be specified, and effective insulation reinforcement can be achieved.

  As a method for detecting a partial discharge occurrence location, a method disclosed in Patent Document 1 has been proposed. The antenna that is the partial discharge sensor is moved in the circumferential direction of the stator to be measured, and the time until the strongest antenna signal is detected is measured, and the antenna position corresponding to the shortest time is specified as the partial discharge occurrence location. .

  In addition, Japanese Patent Application Laid-Open No. 2004-228561 proposes a technique for capturing radiation light with a camera and comparing it with a normal image in order to monitor a temperature abnormality of the rotating electrical machine covered with a casing that does not transmit light.

JP 2005-69745 A International Publication No. WO2008 / 044263

  Electromagnetic waves associated with partial discharge are unstable, and when the stator diameter is small, there is a clear difference in antenna signal strength and detection time difference due to partial discharge even if the antenna position is changed with respect to the stator circumferential direction. Therefore, it may be difficult to specify the location where the partial discharge occurs.

  Further, depending on the voltage level applied to an object such as an electric motor, partial discharge may not occur immediately after application but may occur after several minutes to several hours. In such a case, the occurrence of partial discharge may be missed.

  In addition, in the method of monitoring abnormalities by photographing radiation light with a camera and comparing it with a normal image, light due to temperature rise and light due to partial discharge are measured simultaneously, so it is difficult to distinguish between the two.

  This invention is made | formed in order to solve this subject, The objective is to specify the generation | occurrence | production position of the partial discharge when a voltage is applied to a measuring object.

In order to achieve the above-described object, the present invention provides a discharge position specifying device for specifying a position where a partial discharge is generated when a voltage is applied to a measurement object, and continuously measuring the applied voltage over a predetermined duration. A voltage application unit that supplies the object, a voltage detection unit that continuously measures a voltage value of the applied voltage and outputs a voltage signal, and a partial discharge that occurs in the measurement object when the applied voltage is applied A discharge detector that continuously or electrically detects a predetermined duration of time and a light emitted from the measurement object by the partial discharge continuously over the predetermined duration of time. An image pickup unit that outputs a video signal; a voltage signal from the voltage detection unit; a discharge detection unit signal from the discharge detection unit; and a video signal from the image pickup unit; A signal processing display unit that displays a location where a partial discharge has occurred, and the signal processing display unit includes a voltage signal from the voltage detection unit, a discharge detection unit signal from the discharge detection unit, and an imaging unit. A display processing unit that generates a display signal by superimposing the video signal on the image of the measurement object, and based on the display signal, the location of the partial discharge and the partial discharge A display screen for displaying the detection result of the same on the same screen, and when the ratio of the number of times the discharge detection unit signal from the discharge detection unit exceeds a predetermined threshold to the number of times the voltage is applied exceeds a reference value When the discharge level determination unit that determines that partial discharge has occurred and the discharge level determination unit determines that the partial discharge has occurred, from the voltage detection unit so that it can be reproduced on the display screen. Voltage And having a No., a discharge detector signal from the discharge detection portion, and a file storage unit for storing the video signal from the imaging unit.

The present invention, in the discharge position measuring device for measuring the occurrence position of the partial discharge when a voltage is continuously applied for a predetermined duration to the measurement object, before continuously a voltage value of Kishirushi applied voltage A voltage detection unit that measures and outputs a voltage signal, and a discharge that continuously or electrically detects a partial discharge generated in the measurement object by applying the applied voltage over the predetermined duration. A detection unit; an imaging unit that continuously captures light emitted from the measurement object by the partial discharge over the predetermined duration and outputs a video signal; and a voltage signal from the voltage detection unit. A signal processing display unit that receives a discharge detection unit signal from the discharge detection unit and a video signal from the imaging unit and displays the occurrence location of the partial discharge, and the signal processing Radical 113 includes a voltage signal from the voltage detecting section, and a discharge detector signal from the discharge detector, receives the video signal from the imaging unit, the the video signal to the image of the measurement object In addition, a display processing unit that generates a display signal, a display screen that displays the location of the partial discharge and the detection result of the partial discharge on the same screen based on the display signal, and a display from the discharge detection unit A discharge level determination unit that determines that the partial discharge has occurred when the ratio of the number of times the discharge detection unit signal exceeds a predetermined threshold to the number of times the voltage is applied exceeds a reference value; and the discharge level determination unit When it is determined that the partial discharge has occurred, the voltage signal from the voltage detection unit, the discharge detection unit signal from the discharge detection unit, and the imaging unit are reproducible on the display screen. Video And having a, a file storage unit for storing and.

Further, the present invention provides a discharge location method to determine where the partial discharge when the voltage is applied for a predetermined duration to the measurement object, the signal processing and displaying unit, continuously over a predetermined time duration A voltage data capturing step for capturing a voltage signal from the voltage detection unit, a signal processing display unit for capturing a partial discharge data from the discharge detection unit continuously over the predetermined duration, and a signal processing After the video signal capturing step in which the display unit captures the video signal captured by the imaging unit continuously over the predetermined duration from the imaging unit, the voltage data capturing step, the partial discharge data capturing step, and the video signal capturing step The discharge level determination unit of the signal display processing unit receives a discharge detection unit signal from the discharge detection unit. A determination step of determining that the partial discharge has occurred when a ratio of a number of times exceeding a predetermined threshold to a number of times of application of the voltage exceeds a reference value; and a file storage unit of the signal display processing unit, when the partial discharge in the discharge level determination unit is determined to have occurred, so as to be reproducible in Table示画surface, and the voltage signal from the voltage detecting section, and a discharge detector signal from the discharge detection portion, A storage step for storing the video signal from the imaging unit; a display processing unit; a voltage signal from the voltage detection unit; a discharge detection unit signal from the discharge detection unit; and a video signal from the imaging unit; And a display processing step of generating a display signal by superimposing the video signal on the image of the measurement object .

  ADVANTAGE OF THE INVENTION According to this invention, the generation | occurrence | production position of the partial discharge when a voltage is applied to a measuring object can be specified.

It is a block diagram which shows the structure of the discharge position specific device which concerns on 1st Embodiment. It is a block diagram which shows the structure of the discharge position measuring apparatus which concerns on 1st Embodiment. It is a conceptual diagram which shows the example of the time change of the voltage application in the discharge position measuring device which concerns on 1st Embodiment. It is a screen which shows the example of a display in the signal processing display part in the discharge position measuring device which concerns on 1st Embodiment. It is a flowchart which shows the procedure of the discharge position specification method which concerns on 1st Embodiment. It is a block diagram which shows the structure of the discharge position measuring apparatus which concerns on 2nd Embodiment. It is a screen which shows the example of a display in the signal processing display part in the discharge position measuring device which concerns on 2nd Embodiment. It is a flowchart which shows the procedure of the discharge position specification method which concerns on 2nd Embodiment.

  Hereinafter, a discharge position specifying device, a discharge position measuring device, and a discharge position specifying method 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 common reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is a block diagram showing the configuration of the discharge position specifying device according to the first embodiment. The discharge position specifying device 10 includes a voltage applying unit 11 that applies a voltage to the measurement object 1 and a discharge position measuring device 20.

  Here, a twisted pair sample will be described as an example of the measurement object 1. The twisted pair sample is a sample obtained by twisting enameled wires. Since the twisted pair sample may be twisted after the enamel wire is stretched by 10%, the twisted pair sample is also suitable as an object of the present embodiment when searching for a defect position at this time.

  When the voltage application unit 11 starts voltage application, the voltage application unit 11 ends the voltage application after continuing the application state for a predetermined duration. The voltage to be applied is an impulse voltage generated at a predetermined time interval. Hereinafter, in the present embodiment, the case where the applied voltage a (FIG. 4) is an impulse voltage will be described as an example, but the applied voltage a is not limited to the impulse voltage. For example, it may be a sine wave voltage or a constant voltage. When applying a voltage, the voltage application unit 11 outputs an application start signal to the signal processing display unit 25 described later.

  FIG. 2 is a block diagram showing the configuration of the discharge position measuring apparatus. The discharge position measuring device 20 includes a high voltage probe 21, a discharge detection unit 22, an A / D conversion unit 23, an imaging unit 24, and a signal processing display unit 25. The high voltage probe 21 is a voltage detection unit that measures the voltage applied by the voltage application unit 11. The discharge detector 22 detects the occurrence of the partial discharge when the partial discharge occurs in the measurement object 1. The discharge detector 22 may be of a system that measures electromagnetic waves, such as a loop antenna or a patch antenna. Or the thing of the system of detecting the electric current produced by the partial discharge in the circuit of the measuring object 1 like high frequency CT may be used. Furthermore, an acoustic sensor method for detecting ultrasonic waves generated by partial discharge may be used. Which one should be used may be selected in consideration of environmental conditions at the time of testing.

  The A / D converter 23 receives the voltage signal output from the high voltage probe 21 and performs analog-digital conversion (A / D conversion). The A / D conversion unit 23 receives the discharge detection unit signal b (FIG. 4) output from the discharge detection unit 22 and performs A / D conversion. The voltage signal and the discharge detection unit signal b digitized by the A / D conversion unit 23 are output to the signal processing display unit 25.

  The imaging unit 24 continues exposure for the duration time, images the entire measurement object 1, captures light due to the occurrence of partial discharge, and outputs the image signal to the signal processing display unit 25. As the imaging unit 24, for example, an ultraviolet camera can be used. Further, although one ultraviolet camera may be used, a mirror may be provided on the back side or the side surface in order to reliably capture light emitted from the back side or the side surface as viewed from the ultraviolet camera of the measurement object 1. Alternatively, a plurality of ultraviolet cameras may be provided.

  As shown in FIG. 2, the signal processing display unit 25 includes a display processing unit 25a and a display screen 25b. The display processing unit 25a receives the applied voltage a and the discharge detection unit signal b A / D converted by the A / D conversion unit 23 and the image signal from the imaging unit 24, and generates image data. The display screen 25b displays an image to be described later based on the image data output from the display processing unit 25a. The display processing unit 25a starts a screen data generation process upon receiving an application start signal from the voltage application unit 11.

  FIG. 3 is a conceptual diagram illustrating an example of a temporal change in voltage application in the discharge position measuring apparatus according to the first embodiment. FIG. 3 shows the case of a periodic impulse voltage applied within the duration. The impulse voltage is continuously applied a plurality of times for a predetermined duration, then interrupted and continued for a predetermined time. In the case of FIG. 3, 18 impulse voltages are applied within a predetermined duration. At the start of application, an application start signal is transmitted from the voltage application unit 11 to the display processing unit 25.

  FIG. 4 is a screen showing a display example on the signal processing display unit in the discharge position measuring apparatus according to the first embodiment. The image displayed on the display screen 25b consists of two parts. The image on the left screen 31 is obtained by superimposing the video signal from the imaging unit 24 on the measurement object 1. When light emission due to partial discharge is not present in the video, the image on the left screen 31 is only the image of the measurement object 1. When light emission exists in the video, the light emission image is displayed at a position in the image corresponding to the light emission position.

  It should be noted that the images on the left screen 31 need not all be from the ultraviolet camera. That is, the measurement wavelength differs between the real image of the measurement object 1 that can be seen with the naked eye and the location where the discharge is visible with the ultraviolet rays of the ultraviolet camera. For this reason, an image of the measurement object 1 that can be seen with the naked eye may be recorded in advance, and this may be displayed on the display screen 25b so that the image of the discharge location by the ultraviolet camera is superimposed.

  In the image of the screen 32 on the right side in the display screen 25b, the horizontal axis is time. On the vertical axis, the applied voltage a is shown in the upper portion 32a. Also, the discharge detection unit signal b and the threshold value c are shown in the lower part 32b. In FIG. 4, 10 times of impulse voltages during the duration are displayed on the screen. In the screen 32 on the right side, the discharge detection unit signal b is generated seven times for ten impulse signals. Of these, the threshold value c is exceeded once. The threshold value c is set as a boundary value for determining whether or not partial discharge has occurred when the discharge detection unit signal b is generated. Therefore, in the case of FIG. 4, it can be interpreted that one partial discharge has occurred.

  FIG. 5 is a flowchart showing the procedure of the discharge position specifying method according to the first embodiment. First, a voltage is applied to the measurement object 1 by the voltage application part 11 (step S01). Simultaneously with the start of voltage application, an application start signal is output to the display processing unit 25a of the signal processing display unit 25. The voltage is applied over a predetermined time. In this case, the predetermined time is a time necessary for adding a margin to the time required to confirm whether or not the partial discharge is generated at the applied voltage a at that time.

  When a partial discharge occurs in the twisted pair cable, which is the measurement object 1, in a state where a voltage is applied and light is emitted, imaging by the imaging unit 24 and capturing of the obtained video signal by the signal processing display unit 25 are performed (step S02). ). In addition, in the state where the voltage is applied, the detection of the applied voltage a by the high voltage probe 21 and the capture of the signal of the applied voltage a by the signal processing display unit 25 are performed (step S03). Further, partial discharge is detected by the discharge detection unit 22 and the discharge detection unit signal b is captured by the signal processing display unit 25 with the voltage applied (step S04).

  Next, the display processing unit 25a of the signal processing display unit 25 generates display data based on the captured video signal, applied voltage signal, and partial discharge voltage data (step S05). The display data generation process of the display processing unit 25a is started at the same time when a voltage application start signal is issued from the voltage application unit 11. Next, the display screen 25b displays the display data generated in the display processing unit 25a (step S06).

  The voltage application ends when a predetermined time elapses. Next, it is determined whether or not the test is finished (step S07). If the partial discharge location is displayed on the display screen 25b, the test is completed because the purpose of the test has been achieved. If the partial discharge location is not displayed, or if the display of the partial discharge location is unstable and it is difficult to specify the location of the occurrence, the purpose of the test has not been achieved and the test will not be terminated.

  If the test is not finished (NO in step S07), the voltage applied by the voltage application unit 11 is increased and steps S01 to S06 are repeated. If the test is finished (YES in step S07), the process is finished.

  In the present embodiment as described above, it is possible to visually recognize the occurrence position of the partial discharge generated in the measurement object 1 on the left screen 31 on the display screen 25b. Further, the temporal change in the applied voltage a and the partial discharge detection result can be visually recognized on the screen 32 on the right side on the display screen 25b.

  Only the screen 31 on the left side displays, for example, when light emission occurs due to a rise in temperature, and it is difficult to distinguish from partial discharge. In the present embodiment, by displaying the applied voltage a and the partial discharge detection result, it is possible to clearly distinguish light emission in the case of partial discharge and light emission in the case of not partial discharge.

  Moreover, it is possible to grasp how often the partial discharge is generated by displaying the partial discharge detection result.

  As described above, according to the present embodiment, it is possible to specify the generation position of the partial discharge when a voltage is applied to the measurement object 1.

[Second Embodiment]
FIG. 6 is a block diagram showing a configuration of a discharge position measuring apparatus according to the second embodiment. This embodiment is a modification of the first embodiment. The signal processing display unit 25 further includes a discharge level determination unit 25c and a file storage unit 25d.

  FIG. 7 is a screen showing a display example on the signal processing display unit in the discharge position measuring apparatus according to the second embodiment. The discharge level determination unit 25c (FIG. 6) calculates the ratio of the number of times of the discharge detection unit signal b exceeding the threshold value c with respect to the number of times of the impulse voltage that is the applied voltage a, for example, 10 times of application. The count is sequentially performed every time the impulse voltage is applied. If this ratio exceeds the specified value, the discharge level determination unit 25c determines that the applied voltage a is a partial discharge level voltage, and outputs a message indicating that the voltage is the partial discharge level voltage on the display screen 25b. The determination condition is not limited to this. For example, you may determine with the applied voltage a in case the discharge detection part signal b exceeds the threshold value c being a partial discharge level voltage with respect to all the applied impulse voltages.

  The file storage unit 25d stores data sent from the display processing unit 25a at this time to the display screen 25b. That is, it is possible to reproduce the screen when the discharge level determination unit 25c outputs the partial discharge level based on the data stored in the file storage unit 25d.

  FIG. 8 is a flowchart showing the procedure of the discharge position specifying method according to the second embodiment. The flow from step S01 to step S05 is the same as in the first embodiment. After step S05, it is determined whether the partial discharge level is reached (step S11). When the partial discharge level is not determined (NO in step S11), the applied voltage a is increased (step S08), and step S01 and subsequent steps are repeated.

  If the partial discharge level is determined (step S11 YES), the partial discharge level is displayed including the display (step S12). Further, the file storage unit 25d stores data sent from the display processing unit 25a at this time to the display screen 25b (step S13). Thereafter, it is determined whether or not to end the measurement (step S14). If not, the applied voltage a is increased, and step S01 and subsequent steps are repeated.

  According to the present embodiment as described above, the position of occurrence of partial discharge can be confirmed in a more stable state. Further, by storing the image in that state, the position can be confirmed more accurately.

[Other Embodiments]
As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. For example, in the embodiment, the case where the applied voltage a is an impulse voltage has been described, but the present invention is not limited to this. For example, a sinusoidal voltage may be used. Alternatively, it may be a constant voltage value without changing with time.

  In the embodiment, the twisted pair sample is shown as an example, but the present invention is not limited to this. For example, if there is nothing to block ultraviolet light, infrared light, or visible light and these can be observed directly, a part of a rotating electrical machine, such as a coil end of a random winding model, or a motorlet, etc. The present invention can be applied to other samples as measurement objects.

  Furthermore, these embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention.

  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 the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Measuring object, 10 ... Discharge position specific device, 11 ... Voltage application part, 20 ... Discharge position measuring device, 21 ... High voltage probe (voltage detection part), 22 ... Discharge detection part, 23 ... A / D conversion part, 24 ... Imaging unit, 25 ... Signal processing display unit, 25a ... Display processing unit, 25b ... Display screen, 25c ... Discharge level determination unit, 25d ... File storage unit, a ... Applied voltage, b ... Discharge detection unit signal, c ... Threshold

Claims (8)

In the discharge position specifying device for specifying the position of occurrence of partial discharge when voltage is applied to the measurement object,
A voltage applying unit that continuously supplies an applied voltage to the measurement object over a predetermined duration; and
A voltage detector that continuously measures the voltage value of the applied voltage and outputs a voltage signal;
A discharge detector that continuously or electrically detects a partial discharge generated in the measurement object by applying the applied voltage over the predetermined duration;
An imaging unit that shoots the light emitted from the measurement object by the partial discharge continuously for the predetermined duration and outputs a video signal;
A signal processing display unit that receives a voltage signal from the voltage detection unit, a discharge detection unit signal from the discharge detection unit, and a video signal from the imaging unit, and displays a location where the partial discharge is generated;
With
The signal processing display unit
The voltage signal from the voltage detection unit, the discharge detection unit signal from the discharge detection unit, and the video signal from the imaging unit are received, and the video signal is superimposed on the image of the measurement object and displayed. A display processing unit for generating a signal;
Based on the display signal, a display screen that displays the occurrence location of the partial discharge and the detection result of the partial discharge on the same screen;
A discharge level determination unit that determines that the partial discharge has occurred when the ratio of the number of times the discharge detection unit signal from the discharge detection unit exceeds a predetermined threshold to the number of times the voltage is applied exceeds a reference value;
When the discharge level determination unit determines that the partial discharge has occurred, the voltage signal from the voltage detection unit and the discharge detection unit signal from the discharge detection unit are reproducible on the display screen. A file storage unit that stores the video signal from the imaging unit;
A discharge position specifying device comprising:   The discharge position specifying device according to claim 1, wherein the applied voltage is an impulse voltage.   The discharge position specifying device according to claim 1, wherein the applied voltage is a sine wave voltage.   The discharge position specifying device according to any one of claims 1 to 3, wherein the imaging unit is an ultraviolet camera. The display processing unit, when the discharge level determination unit determines that the partial discharge has occurred, outputs a display content indicating that the partial discharge has occurred to the signal processing display unit. The discharge position specifying device according to any one of claims 1 to 4. In a discharge position measuring device that measures the occurrence position of partial discharge when a voltage is continuously applied to a measurement object for a predetermined duration,
A voltage detecting unit that outputs a measured voltage signal continuously a voltage value before Kishirushi applied voltage,
A discharge detector that continuously or electrically detects a partial discharge generated in the measurement object by applying the applied voltage over the predetermined duration;
An imaging unit that shoots the light emitted from the measurement object by the partial discharge continuously for the predetermined duration and outputs a video signal;
A signal processing display unit that receives a voltage signal from the voltage detection unit, a discharge detection unit signal from the discharge detection unit, and a video signal from the imaging unit, and displays a location where the partial discharge is generated;
With
The signal processing display unit
The voltage signal from the voltage detection unit, the discharge detection unit signal from the discharge detection unit, and the video signal from the imaging unit are received, and the video signal is superimposed on the image of the measurement object and displayed. A display processing unit for generating a signal;
Based on the display signal, a display screen that displays the occurrence location of the partial discharge and the detection result of the partial discharge on the same screen;
A discharge level determination unit that determines that the partial discharge has occurred when the ratio of the number of times the discharge detection unit signal from the discharge detection unit exceeds a predetermined threshold to the number of times the voltage is applied exceeds a reference value;
When the discharge level determination unit determines that the partial discharge has occurred, the voltage signal from the voltage detection unit and the discharge detection unit signal from the discharge detection unit are reproducible on the display screen. A file storage unit that stores the video signal from the imaging unit;
A discharge position measuring apparatus comprising: In the discharge position specifying method for specifying the location of occurrence of partial discharge when a voltage is applied to the measurement object over a predetermined duration,
A voltage data capturing step in which the signal processing display unit continuously captures the voltage signal from the voltage detection unit over the predetermined duration;
A partial discharge data capturing step in which the signal processing display unit continuously captures partial discharge data from the discharge detection unit over the predetermined duration;
A signal processing display unit that captures a video signal captured by the imaging unit continuously over the predetermined duration from the imaging unit; and
After the voltage data capturing step, the partial discharge data capturing step and the video signal capturing step,
The partial discharge when the discharge level determination unit of the signal display processing unit exceeds the reference value when the ratio of the number of times that the discharge detection unit signal from the discharge detection unit exceeds a predetermined threshold to the number of times of application of the voltage A determination step for determining that has occurred;
File storage unit of the signal display processing unit, when the partial discharge in the discharge level determination unit is determined to have occurred, so as to be reproducible in Table示画surface, and the voltage signal from the voltage detecting section, A storage step of storing a discharge detection unit signal from the discharge detection unit and a video signal from the imaging unit;
The display processing unit accepts a voltage signal from the voltage detection unit, a discharge detection unit signal from the discharge detection unit, and a video signal from the imaging unit, and the video signal is an image of the measurement object. Again, a display processing step of generating a display signal to,
A discharge position specifying method characterized by comprising: In the display processing step, when it is determined in the determination step that the partial discharge has occurred, the display processing unit further outputs a display content indicating that the partial discharge has occurred on a display screen. Item 8. The discharge position specifying method according to Item 7 .

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