JP2008232973A - Device and method for determining partial discharge of electric apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately locate the partial discharge occurrence in a vessel of an electric apparatus by removing the factors and noises other than the partial discharge in the vessel. <P>SOLUTION: An ultrasonic sensor 15 detects an acoustic signal in the vessel 13 storing a body section 14 of the electric apparatus, an electric current detector 16 detects a current pulse flowing in the vessel 13 storing the body section 14 of the electric apparatus, and a data collection section 19 starts to collect the acoustic signal from the ultrasonic sensor 15 when the electric current detector 16 detects the current pulse, and records it on a recording section 20. A timer means 21 time-delay-operates after the electric current detector 16 detects the current pulse, and returns after a predetermined time after the detection of the current pulse. A determining means 22 determines the partial discharge part of the electric apparatus based on the acoustic signal from the ultrasonic sensor 15 collected during operation of the timer means 21. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a partial discharge determination device and method for an electric device that detects and determines partial discharge of an electric device accommodated in a container.

  For example, a transformer, which is an electrical device, is formed by enclosing a transformer body composed of an iron core and a winding in a container and enclosing insulating oil or insulating gas. In such a transformer, when a partial discharge is generated inside the container, a current pulse and an acoustic signal are generated accordingly, so that the partial discharge generated inside the container is detected by detecting the current pulse and the acoustic signal. I have to. For example, a current detector that detects the current flowing through the container and a plurality of ultrasonic sensors are installed on the outer surface of the container, and the current pulse is used as a trigger to generate a discharge due to the time difference from the discharge of the acoustic signal detected by the ultrasonic sensor. The position is determined.

  There is one in which an ultrasonic sensor is arranged at a specific position on the outer surface of a stationary equipment tank body so that the discharge generation position is easily determined (for example, see Patent Document 1). This consists of two sets of two ultrasonic sensors as one set, arranged so as to be symmetric with respect to the outer surface of the tank body of the stationary device, and the difference in detection time from the ultrasonic sensor to the discharge generation position and in the insulating medium. It was generated in a stationary device by calculating the coordinates on the coordinate axis of the discharge generation position from the distance data of one set of ultrasonic sensors obtained from the sound velocity, and executing the calculation for the three sets of ultrasonic sensors. The discharge position is determined.

In addition, using the detection of electric discharge by the electric sensor as a trigger, the detection waveform of the vibration sensor is averaged to reduce vibration sensor noise, and partial discharge position is determined from the rising point of the vibration sensor waveform. Instead of triggering sensor detection, partial discharge that occurs inside the gas insulation device by capturing the vibration sensor waveform when the time difference between the previous detection and the current detection by the electrical sensor is greater than a certain value. There is one in which the location of the occurrence position is accurately determined (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 10-54862 JP 2003-28910 A

  However, the current detector may detect the current pulse due to a factor other than the partial discharge in the container, and the ultrasonic sensor may detect the acoustic signal due to a factor other than the partial discharge in the container. For example, the current detector generates a current pulse due to a factor other than partial discharge in the container due to the switching operation of the switch around the transformer, the switching operation of the tap switch of the tap switching transformer, or lightning or noise. Or an ultrasonic sensor may detect an acoustic signal. In such a case, it is difficult to determine partial discharge.

  Although the partial discharge position can be determined with accuracy in Patent Document 1, the partial discharge position is determined even when the current detector or the ultrasonic sensor detects a signal due to noise. Further, in Patent Document 2, the detection of the vibration sensor waveform is not performed when the time difference between the previous detection and the current detection by the electric sensor is equal to or greater than a predetermined value, instead of merely using the electric sensor detection as a trigger. Even if it is a partial discharge that occurs continuously, it can be accurately detected, but no measures are taken when the current detector or ultrasonic sensor detects a signal due to noise. Even in this case, it may be determined that the discharge is partial discharge.

  An object of the present invention is to provide a partial discharge determination device and method for an electric device that can remove factors other than the partial discharge in the vessel and noise, and can accurately determine the occurrence of the partial discharge in the vessel of the electric device. That is.

  An apparatus for determining partial discharge of an electric device according to a first aspect of the present invention includes an ultrasonic sensor installed on an outer surface of a container housing a main body of the electric device, and a current pulse flowing in the container housing the main body of the electric device. A current detector to detect, a data collection unit that starts collecting acoustic signals from the ultrasonic sensor when the current detector detects a current pulse and records it in a recording unit; and the current detector detects a current pulse. Timer means that operates for a limited time after the current pulse is detected and returns after a lapse of a predetermined time, and a partial discharge portion of the electric device based on an acoustic signal collected from the ultrasonic sensor collected during the operation time of the timer means. And determining means for determining.

According to a second aspect of the present invention, there is provided a partial discharge determination device for an electric device according to the first aspect of the present invention, wherein the device operation detection device for an external noise generation source is provided, and the determination means includes the determination result of the partial discharge portion of the electric device. The operation information of the device operation detection device is given.
According to a third aspect of the present invention, there is provided the partial discharge determination device for an electric device according to the first or second aspect, wherein the time limit operation of the timer means is from the ultrasonic sensor to a portion of the shortest distance of the electric device. The time when the acoustic signal is propagated with respect to the distance, the time when the marginal value is expected, the time limit of the time-return of the timer means is the acoustic signal relative to the distance from the ultrasonic sensor to the longest distance part of the electric device. It is a time that allows for a margin value in the propagation time.

  According to the present invention, when the current pulse is detected, the acoustic signal from the ultrasonic sensor is started to be collected, and based on the acoustic signal from the ultrasonic sensor collected during the operation time determined by the timer means, Since the partial discharge portion is determined, it is possible to determine the partial discharge of the electric device by removing the influence of obvious noise. In addition, when the device operation detection device of the external noise generation source operates, the operation information of the device operation detection device is added to the determination result of the partial discharge site of the electric device, so the partial discharge due to factors other than the partial discharge in the container Misjudgment with judgment can be suppressed. In addition, since the operation time determined by the timer means is set to a time within a range in which the ultrasonic sensor can detect the acoustic signal due to the partial discharge with the current pulse as a trigger, The sound signal by discharge is surely included.

  FIG. 1 is a configuration diagram of a partial discharge determination device for an electrical apparatus according to an embodiment of the present invention. In FIG. 1, the case where the partial discharge determination apparatus 12 is applied to the transformer 11 as an electric equipment is shown.

In the container 13 of the transformer 11, an iron core and a winding, which are the main body 14 of the transformer, are enclosed and filled with insulating oil or insulating gas. A plurality of ultrasonic sensors 15 for detecting acoustic signals of partial discharge generated in the container 13 are installed on the outer surface of the container, and current detection for detecting current pulses of partial discharge generated in the container 13 is provided. A vessel 16 is installed.

  Moreover, the apparatus operation | movement detection apparatus 17 which detects that the apparatus of the periphery of the transformer 11 operate | moved is provided. For example, when the transformer 11 is a tap switching transformer, a device operation detector 17 that detects an operation signal of the tap switch is provided, and a device operation detection that detects the opening / closing operation of the switch near the transformer 11 is provided. A vessel 17 is provided.

  Detection signals from the ultrasonic sensor 15, the current detector 16, and the device operation detector 17 are input to the data collection unit 19 via the input unit 18 of the partial discharge determination device 12. When the current detector 16 detects a current pulse, the data collection unit 19 starts collecting acoustic signals from the ultrasonic sensor 15 and records them in the recording unit 20. If a partial discharge is generated in the container 13, a current pulse due to the partial discharge is detected before the acoustic signal detected by the ultrasonic sensor 15, so that the ultrasonic wave is detected after the current detector 16 detects the current pulse. Collection of acoustic signals from the sensor 15 is started. This is because the current pulse is conducted to the outer surface of the container 13 at almost the same speed as the speed of light and flows to the ground, but the acoustic signal propagates through the insulating oil (insulating gas) filled in the container 13 to the outer surface of the container 13. This is because a time delay occurs in the detection of the acoustic signal.

  Next, the timer means 21 operates for a time limit after the current detector 16 detects the current pulse, and returns after a predetermined time has elapsed since the current pulse was detected. ) Is input to the determination means 22. And the determination means 22 inputs the acoustic signal from the ultrasonic sensor 15 collected during the operation time of the timer means 21 from the recording part 21, and determines the partial discharge site | part of an electric equipment based on the acoustic signal. This is because the acoustic signal detected by the ultrasonic sensor 15 includes an acoustic signal due to noise, so that the acoustic signal detected by the ultrasonic sensor 15 due to factors other than partial discharge is excluded.

  The partial discharge site of the electrical device determined by the determination unit 22 is recorded in the recording unit 20 and, if necessary, displayed on the display device 24 via the output unit 23 and printed on the printer 25. In this case, not only the partial discharge site of the electrical device as the determination result but also the acoustic signal data recorded in the recording unit 20 is output together. When the operation information of the device operation detection device 17 is recorded, the operation information is also output. Further, the data recorded in the recording unit 20 is transmitted to the host system 26 via the communication device 27 as necessary or in response to a request from the host system 26.

  FIG. 2 is a cross-sectional view of the main body 14 housed in the container 13 of the transformer 11. FIG. 2 shows a case where four ultrasonic sensors 15 a to 15 d are installed on the outer surface of the container 13. The container 13 is filled with insulating oil (insulating gas) 28, and the main body 14 in which the coil 30 is wound around the iron core 29 is accommodated. The partial discharge occurs at any part of the main body 14. The partial discharge generated in any part of the main body part 14 propagates from the discharge part to the ultrasonic sensors 15a to 15d via the main body part 14, the insulating oil (insulating gas) 28, and the container 13.

  Now, it is assumed that a partial discharge has occurred in the portion A1 of the main body portion 14. In this case, the current pulse is discharged through the ground wire provided in the container 13 and detected by the current detector 16. On the other hand, the acoustic signal propagates through the insulating oil (insulating gas) 28, the main body 14 and the container 13 and propagates to each of the ultrasonic sensors 15a to 15d. Therefore, the ultrasonic sensor 15a having the shortest distance from the partial discharge site A1 to the ultrasonic sensors 15a to 15d first detects the acoustic signal. Hereinafter, similarly, acoustic signals are detected in the order of the ultrasonic sensors 15b, 15d, and 15c in the order close to the partial discharge site A1.

  Each of the ultrasonic sensors 15a to 15d has a different order of acoustic signals to be detected depending on the position of the partial discharge portion A1, but the ultrasonic sensor 15 that first detects the acoustic signal has the closest partial discharge position A1. The ultrasonic sensor 15 that finally detects an acoustic signal is an ultrasonic sensor farthest from the partial discharge position A1. From this, from the relationship between the installation positions of the ultrasonic sensors 15a to 15d and the assumed partial discharge position A1, the time until the first acoustic signal is detected after the current pulse is generated and the last The time until the acoustic signal is detected can be set in advance.

  Therefore, the time limit of the time limit operation of the timer means 21 is set to a time when an allowance is expected for the time during which the acoustic signal propagates with respect to the distance from the ultrasonic sensors 15a to 15d to the shortest part of the main body 14, and the timer means The time limit of 21 time-return is a time in which a margin value is expected for the time during which the acoustic signal propagates with respect to the distance from the ultrasonic sensors 15a to 15d to the longest distance portion of the main body 14.

  Note that the propagation speed of the acoustic signal differs depending on the propagation medium, and in general, the propagation speed of the metal is faster than that of the insulating oil. Therefore, the distance from the partial discharge site A1 to the ultrasonic sensors 15a to 15d is the ultrasonic wave from the partial discharge site A1. It can be approximated to the shortest distance to the inner surface of the container 13 to which the sensors 15a to 15d are attached.

  FIG. 3 is a waveform diagram showing an example of the acoustic signals S1 to S4 detected by the ultrasonic sensors 15a to 15d. In this example, a case is shown in which partial discharge has occurred at a portion of the main body portion 14 at the shortest distance from any of the ultrasonic sensors 15a to 15d. Assume that a current pulse is detected at time t1. Then, the timer means 21 starts counting the time limit operation and operates at the time t2. The time period T1 from the time point t1 to the time point t2 is a time period in which the acoustic signal propagates with respect to the distance from any one of the ultrasonic sensors 15a to 15d to the shortest distance portion of the main body 14 and the time T2 is estimated to allow for a margin value ΔT2. It is. Therefore, during the time period T1, it is a time region in which an acoustic signal due to partial discharge is not generated.

  Then, at time t3, the ultrasonic sensor 15 closest to the partial discharge site detects the acoustic signal S1, and similarly, the acoustic signal S2 at time t4 in the order of the ultrasonic sensors 15 in order of proximity to the partial discharge site A1. The acoustic signal S3 is detected at time t5, and the acoustic signal S4 is detected at time t6. In this case, the timer means 21 returns to operation after a predetermined time period T4 from the time point t1. That is, the timer means 21 returns after a time T4 when a margin value ΔT3 is expected in the time T3 in which the acoustic signal propagates with respect to the distance from the ultrasonic sensors 15a to 15d to the longest part of the main body 14. . Therefore, after the elapse of the time period T4, it is a time region in which an acoustic signal due to partial discharge is not generated.

  Thus, the operation time (t2 to t7: T0) of the timer means 21 defines a time region in which an acoustic signal due to partial discharge is generated, and the acoustic signal generated in the region of the operation time T0 of the timer means 21. Can be determined as an acoustic signal due to partial discharge, and an acoustic signal generated in an area other than the operating time T0 of the timer means 21 can be determined not to be an acoustic signal due to partial discharge.

  FIG. 4 is a waveform diagram showing another example of the acoustic signals S1 to S4 detected by the ultrasonic sensors 15a to 15d. FIG. 4 (a) shows the operation time T0 of the timer means 21 when a current pulse is detected. FIG. 4B is a waveform diagram of an example when the ultrasonic sensor has previously detected an acoustic signal. FIG. 4B shows a case in which a current pulse is detected but the ultrasonic sensor detects an acoustic signal after the operation time T0 of the timer means 21 has elapsed. It is an example waveform diagram. In the case of FIGS. 4A and 4B, both are acoustic signals generated in a region other than the operating time T0 of the timer means 21, and therefore, it is determined that the acoustic signal is not an acoustic signal due to a partial discharge generated current pulse. The Therefore, the acoustic signal in this case is determined to be an acoustic signal due to external noise.

  FIG. 5 is a flowchart showing the processing operation of the partial discharge determination device 12. First, it is determined whether or not a current pulse is detected by the current detector 16 (S1). When a current pulse is detected, the timer means 21 is activated and an acoustic signal detected by the ultrasonic sensors 15a to 15d. Starts recording (S2). Then, after a current pulse is input, a predetermined time period T1 determined by the timer means 21 has passed, and it is determined whether or not the timer means 21 has operated for a time limit (S3). It is determined whether or not there is a signal (S4). If there is an acoustic signal, the acoustic signal is determined as external noise.

  Next, a predetermined time period T4 determined by the timer means 21 has elapsed since the input of the current pulse, and it is determined whether or not the timer means 21 has returned to operation (S6). Then, it is determined whether or not there is an acoustic signal in the time domain during the operation time T0 of the timer means 21 (S7), and when there is an acoustic signal, the partial discharge site is based on the acoustic signal during the operation time T0 of the timer means 21 Is determined (S8).

  On the other hand, if it is determined in step S7 that there is no acoustic signal during the operation time T0 of the timer means 21, it is determined that the noise is external noise (S9).

  Thus, since the partial discharge site is determined based on the acoustic signal generated in the time domain of the operation time T0 of the timer means 21, the partial discharge site determination is performed even for the acoustic signal due to external noise. Therefore, the accuracy of the determination of the partial discharge position is improved. The partial discharge site is determined by inputting the current pulse flowing to the ground due to the partial discharge detected by the current detector 16 and the acoustic signal detected by the ultrasonic sensor 15 and determining the presence or absence of the partial discharge phenomenon from the time difference. For example, as shown in Patent Document 1, the determination is made from the delay times of the acoustic signals from the plurality of ultrasonic sensors 15. Usually, it is understood that partial discharge has occurred when the number of ultrasonic sensors 15 is one. When the number of ultrasonic sensors 15 is two, in addition to the occurrence of partial discharge, a rough area of the partial discharge site can be seen. When the number of ultrasonic sensors 15 is three, the partial discharge site where the partial discharge area is narrowed down is known.

  Here, even an acoustic signal within the operating time T0 of the timer means 21 may be caused by external noise. For example, the ultrasonic sensors 15a to 15d may detect acoustic signals due to the effects of switching operations of the switches around the transformer, switching operations of the tap switching devices of the tap switching transformer, or lightning and noise. Therefore, when there is operation information of the device operation detection device 17 for the determination result of the partial discharge determination portion by the acoustic signal within the operation time T0 of the timer means 21, the operation information is used as the determination result of the partial discharge portion. To be recorded. Thereby, the determination result of the partial discharge site can be analyzed with higher accuracy.

  According to the embodiment of the present invention, the current detector 16 for detecting the current pulse flowing to the ground due to the partial discharge and the ultrasonic sensor 15 for detecting the acoustic signal due to the partial discharge are provided, and the ultrasonic wave is detected when the current pulse is detected. Since the acoustic signal from the sensor 15 is started to be collected and the partial discharge portion of the main body 14 of the transformer is determined based on the acoustic signal collected during the operation time T0 determined by the timer means 21, the influence of obvious noise The partial discharge of the electric device can be determined based on the acoustic signal generated by the partial discharge.

  Further, when the acoustic signal collected during the operation time T0 determined by the timer means 21 is an acoustic signal when the device operation detection device 17 of the external noise generation source is operated, the part determined based on the acoustic signal Since the operation information of the device operation detection device 17 is given to the determination result of the discharge part, erroneous determination with partial discharge determination due to factors other than partial discharge in the container 13 can be suppressed.

  In addition, the operation time T0 determined by the timer means 22 is set to a time within a range in which the ultrasonic sensor 15 can detect the acoustic signal due to the partial discharge with the current pulse as a trigger. Can reliably include an acoustic signal due to partial discharge.

The block diagram of the partial discharge determination apparatus of the electric equipment concerning embodiment of this invention. Sectional drawing of the main-body part accommodated in the container of the transformer which is an electric equipment in embodiment of this invention. The wave form diagram which shows an example of the acoustic signal detected by each ultrasonic sensor in embodiment of this invention. The wave form diagram which shows another example of the acoustic signal detected by each ultrasonic sensor in embodiment of this invention. The flowchart which shows the processing operation of the partial discharge determination apparatus of the electric equipment concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Transformer, 12 ... Partial discharge determination apparatus, 13 ... Container, 14 ... Main-body part, 15 ... Ultrasonic sensor, 16 ... Current detector, 17 ... Apparatus operation detection apparatus, 18 ... Input part, 19 ... Data collection part , 20 ... recording section, 21 ... timer means, 22 ... determination means, 23 ... output section, 24 ... display device, 25 ... printer, 26 ... host system, 27 ... communication device, 28 ... insulating oil (insulating gas), 29 ... iron core, 30 ... coil

Claims (4)

An ultrasonic sensor installed on the outer surface of the container containing the main body of the electrical device;
A current detector for detecting a current pulse flowing in a container housing the main body of the electrical device;
A data collection unit that starts collecting acoustic signals from the ultrasonic sensor and records them in a recording unit when the current detector detects a current pulse; and
Timer means that operates for a time after the current detector detects a current pulse and returns after a predetermined time has elapsed after detecting the current pulse;
Determining means for determining a partial discharge site of the electric device based on an acoustic signal collected from the ultrasonic sensor collected during an operation time of the timer means;
A partial discharge determination device for an electrical device, comprising:   2. The apparatus according to claim 1, further comprising an apparatus operation detection device for an external noise generation source, wherein the determination unit adds operation information of the apparatus operation detection device to a determination result of a partial discharge site of the electric apparatus. Partial discharge determination device.   The time limit of the time limit operation of the timer means is the time when the acoustic signal propagates with respect to the distance from the ultrasonic sensor to the shortest distance part of the electric equipment, the time limit recovery of the timer means 3. The electricity according to claim 1, wherein the time period is a time in which a margin value is expected for a time during which an acoustic signal propagates with respect to a distance from the ultrasonic sensor to a longest distance portion of the electric device. Equipment for partial discharge determination of equipment. When the current pulse flowing in the container containing the main body of the electric device is detected, the acoustic signal from the ultrasonic sensor installed on the outer surface of the container is started and recorded,
On the other hand, after detecting the current pulse, the timer means is operated for a time limit and the timer means is returned after a predetermined time has elapsed since the current pulse was detected,
A partial discharge determination method for an electric device, comprising: determining a partial discharge portion of the electric device based on an acoustic signal from the ultrasonic sensor collected during an operation time of the timer means.

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