JP2008304357A - Partial discharge measurement device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small partial discharge measurement device which reduces influence of signal attenuation and noise, and enhances the sensitivity of detection of partial discharge. <P>SOLUTION: The device includes a patch antenna 2 for detecting an electromagnetic wave radiated due to partial discharge generated by a deterioration in insulation of an electrical apparatus, an electromagnetic-wave detection circuit 3 for measuring partial discharge from a detection signal from the patch antenna 2, a composite multilayer substrate 11 where the patch antenna 2 and the detection circuit 3 are mounted. The detection circuit 3 is covered from both sides with a grounding electrode 12 and an electromagnetic-wave shielding case 18 for performing shielding from electromagnetic waves. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for measuring partial discharge accompanying insulation deterioration of a high-voltage device.

  In a conventional partial discharge measuring device, high voltage equipment deteriorates in an insulator due to long-term operation, and partial insulation occurs when insulation deterioration occurs. Therefore, the partial deterioration is measured to diagnose the insulation deterioration state. . As one of the methods for measuring the partial discharge, an electromagnetic wave generated with the partial discharge is measured. For example, radiated electromagnetic wave detection that consists of a high-frequency antenna provided inside the frame of a rotating electrical machine at the position facing the end of the stator winding. By using the means, an electromagnetic wave having a center frequency in the range of 1 to 3 GHz is detected in a narrow band having a bandwidth of 1 MHz and transmitted to the partial discharge signal processing means through the signal cable. Since there is no radiated electromagnetic wave generation source in the GHz band other than partial discharge inside the frame of the rotating electrical machine, the detected electromagnetic wave is generated inside the rotating electrical machine by detecting the radiated electromagnetic wave in the 1 to 3 GHz band with a bandwidth of 1 MHz. It can be identified that the partial discharge has occurred (for example, see Patent Document 1).

  There are the following detectors for detecting electromagnetic waves. The electromagnetic wave focused by the concave mirror (external circuit) is introduced into a half-wavelength antenna (gain of about 6 dB) made of a semi-insulating conductor manufactured on a semi-insulating semiconductor substrate transparent to the electromagnetic wave. Detected at a semiconductor junction formed by, for example, a Schottky junction formed in a semiconductor portion selectively grown therein, and taken out through a terminal. Thus, since the antenna portion and the semiconductor junction portion are configured on the same substrate, the mechanical and electrical stability is good (see, for example, Patent Document 2).

  In addition, in order to detect electromagnetic waves, a plurality of minute antenna elements are formed in a line by a conductor pattern on a printed circuit board, and a plurality of frequency selection signal detections are performed on the surface opposite to the surface on which the minute antenna elements are formed. The parts are arranged in rows. With such a configuration, it is possible to measure the near electromagnetic field intensity radiated from the electronic device while minimizing interference caused by unnecessary radiation generated from various electronic devices. Since the selected frequency covers a wide range from 30 MHz to 1 GHz, about 1000 frequency selection signal level detection circuits corresponding to one-to-one are connected to a wire loop antenna for detecting electromagnetic radiation, and the detection output is stored. A plurality of signal level information corresponding to electromagnetic radiation levels detected from a plurality of wire loop antennas are simultaneously measured and stored, connected to the apparatus and the CPU (see, for example, Patent Document 3).

  In addition, a detection circuit using diode detection for detecting radio waves in the mobile phone band to microwave oven band and measuring the integrated amount of electromagnetic waves exposed to the human body and a small antenna, etc. shall be provided on the front and back of the same printed circuit board. It is downsized by. The detection unit functions as a micro-split antenna or a printed circuit board dipole antenna, which is a small antenna with a wide band in the gigahertz band by being tapered in addition to downsizing with a planar antenna, In order to increase the bandwidth to detect up to 2.5 GHz, the antenna shape is printed in a tapered shape on a printed circuit board (see, for example, Patent Document 4).

Japanese Patent Application Laid-Open No. 11-23310 (page 5, FIG. 2) JP-A-52-50154 (pages 1 and 2, FIG. 2) Japanese Patent Laid-Open No. 9-304456 (Page 4, FIGS. 2 and 3) Japanese Unexamined Patent Publication No. 2003-194862 (pages 3 to 4, FIGS. 1 and 2)

  In a conventional partial discharge measuring apparatus, a radiated electromagnetic wave detecting means is installed inside a rotating electrical machine, and a partial discharge signal processing means is installed outside the rotating electrical machine to measure the partial discharge of the rotating electrical machine. In such a configuration, the radiated electromagnetic wave detection means and the partial discharge signal processing means are separate devices, and both need to be connected by a high-frequency coaxial cable. However, since the signal to be detected is a high frequency in the GHz band, the coaxial cable Due to this, there is a drawback that signal attenuation occurs. Further, since the radiated electromagnetic wave detecting means and the partial discharge signal processing means are separated from each other, there is a problem that the apparatus becomes large and miniaturization is difficult. Furthermore, there is a problem that noise enters due to the cable connecting portion and the cable and the S / N deteriorates.

  Further, as in the prior art documents 2 to 4, a method of providing an antenna and an electromagnetic wave detector on the same substrate is described as a method of detecting an electromagnetic wave. However, the prior art document 2 shows an electromagnetic wave detector in the submillimeter wave region applied to the beam guide system, and suppresses the noise in an environment with a lot of electromagnetic noise such as a power distribution board or a high voltage rotating machine. There was a problem that discharge could not be measured with high sensitivity. In the prior art document 3, the antenna used is a small antenna with a loop length of about 3 to 8 mm, and the noise is suppressed in an environment with a lot of electromagnetic noise such as a power distribution board or a high-voltage rotating machine. Discharge cannot be measured with high sensitivity, and furthermore, since a range of 30 MHz to 1 GHz is scanned and detected at a high speed, measuring partial discharge with this method detects many noises other than partial discharge, resulting in poor S / N. There was a problem. The prior art document 4 measures a wide range of magnetic fields and radio waves in the range of 0.9 to 2.5 GHz, so it detects a lot of noise other than partial discharge, so the S / N is bad, and the switchboard and high-voltage rotation There is a problem that partial discharge cannot be measured with high sensitivity by suppressing noise in an environment with a lot of electromagnetic noise such as a machine.

  The present invention has been made to solve the above-described problems, and is intended to obtain a small and highly sensitive partial discharge measuring apparatus having a small signal attenuation of electromagnetic waves accompanying partial discharge and excellent noise resistance.

  The partial discharge measuring apparatus according to the present invention includes an antenna that detects an electromagnetic wave radiated along with a partial discharge that occurs due to insulation deterioration of an electrical device, an electromagnetic wave detection circuit that measures a partial discharge based on a detection signal from the antenna, An antenna and an electromagnetic wave detection circuit, and a substrate on which a planar electrode insulated from the electromagnetic wave detection circuit is formed. The electromagnetic wave detection circuit is installed in an area corresponding to the area where the planar electrode is formed to shield the electromagnetic wave. It is characterized by being covered with an electromagnetic wave shielding body.

  According to the present invention, the electromagnetic wave detection circuit and the antenna are arranged close to each other, and the electromagnetic wave detection circuit is covered with the electromagnetic wave shielding casing and the planar electrode, so that the influence of the electromagnetic wave signal attenuation and electromagnetic wave noise caused by the partial discharge is reduced. The discharge detection sensitivity can be increased.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a configuration of a partial discharge measuring apparatus showing Embodiment 1 for carrying out the present invention. FIG. 2 is a perspective view of the state where the dielectric casing is removed from the partial discharge measuring apparatus shown in FIG. 1 as viewed from the patch antenna side. FIG. 3 is a perspective view of the partial discharge measuring device shown in FIG. 1 as viewed from the electromagnetic shielding housing side. In FIG. 1, a partial discharge measuring apparatus 1 includes a patch antenna 2 provided on a composite multilayer substrate 11, an electromagnetic wave detection circuit 3 provided on the composite multilayer substrate 11, and an electromagnetic wave that shields the electromagnetic wave and covers the electromagnetic wave detection circuit 3. An electromagnetic wave shielding casing 18 that is a shielding body, a dielectric casing 19 that covers the patch antenna 2, a composite cable 5, a power source 6, and a detection signal output means 7 are configured.

  The patch antenna 2 is an antenna that detects an electromagnetic wave radiated with a partial discharge generated due to insulation deterioration of a high-voltage device that is an electrical device. The electromagnetic wave detection circuit 3 measures partial discharge based on the detection signal from the patch antenna 2. The patch antenna 2 and the electromagnetic wave detection circuit 3 are installed on a composite multilayer substrate 11 which is the same substrate. In the present embodiment, the electromagnetic wave detection circuit 3 is installed on one surface of the composite multilayer substrate 11, and the patch antenna 2 is installed so as to face the other surface of the composite multilayer substrate 11.

  The composite multilayer substrate 11 includes a first circuit board 14 and a second circuit board 15. An antenna dielectric 13 is provided on the second circuit board 15 side of the composite multilayer substrate 11 via a ground electrode 12 that is a planar electrode. The electromagnetic wave detection circuit 3 and the ground electrode 12 are insulated. As shown in FIG. 1, the electromagnetic wave detection circuit 3 is installed so as to face a region corresponding to a region where the ground electrode 12 is formed. The antenna dielectric 13 is provided with a receiving electrode 16 on the surface, and a ground electrode 12 is provided on the opposite side of the composite multilayer substrate 11 side. Reception from the reception electrode 16 is performed via the feeder line 17. The feed line 17 connected to the receiving electrode 16 is patterned on the surface of the antenna dielectric 13 in the form of a split line as shown in FIG. The patch antenna 2 includes a ground electrode 12, an antenna dielectric 13, a reception electrode 16, and a feed line 17.

  Here, a partial cross-sectional view of the composite multilayer substrate 11 is shown in FIG. A through hole 23 is formed in the composite multilayer substrate 11. The through hole 23 constitutes a part of the feeder line 17 that connects the electromagnetic wave detection circuit 3 and the patch antenna 2. By forming the through hole 23, the wiring distance between the receiving electrode 16 and the feeding circuit pattern 45 of the electromagnetic wave detection circuit 3 is configured to be shortest through the feeding line 17. The through hole 23 is formed to be insulated from the ground electrode 12 and the second circuit pattern 47, and is connected to the power supply circuit pattern 45 of the electromagnetic wave detection circuit 3 formed on the first circuit board 14. A detection circuit pattern 46 is also formed on the first circuit board 14.

  One surface of the composite multilayer substrate 11 is covered with an electromagnetic shielding housing 18 having a fitting shape that matches the outer dimensions thereof. By providing the electromagnetic shielding case 18, electromagnetic noise from the outside to the electromagnetic wave detection circuit 3 is shielded, the electromagnetic wave detection circuit 3 is mechanically protected, and the electromagnetic wave detection circuit 3 is also protected from humidity. The surface opposite to the surface on which the electromagnetic wave detection circuit 3 is installed on the composite multilayer substrate 11 is covered with the ground electrode 12. That is, the electromagnetic wave detection circuit 3 is configured to be covered from both surfaces by the electromagnetic wave shielding casing 18 and the ground electrode 12. With this configuration, it is possible to prevent electromagnetic noise from entering the electromagnetic wave detection circuit 3. The area where the electromagnetic shielding casing 18 faces the composite multilayer substrate 11 is larger than the area of the ground electrode 12 constituting the patch antenna 2. With such a configuration, it is possible to more reliably prevent electromagnetic noise from entering the electromagnetic wave detection circuit 3. The electromagnetic shielding casing 18 is provided with an airtight terminal 22, and the composite cable 5 is led out of the electromagnetic shielding casing 18. The electromagnetic shielding casing 18 is made of metal.

  The patch antenna 2 provided on the other surface side of the composite multilayer substrate 11 is covered with a dielectric casing 19. The dielectric casing 19 and the electromagnetic shielding casing 18 form an airtight structure by the packing 20 provided in the packing groove 26 of the electromagnetic shielding casing 18. For this reason, the patch antenna 2, the electromagnetic wave detection circuit 3, and the composite multilayer substrate 11 have a structure that is protected from the outside air and humidity. The dielectric casing 19 and the electromagnetic shielding casing 18 are fixed by inserting screws 21 into the screw holes 25 of the electromagnetic shielding casing 18.

  The patch antenna 2 has a detection center frequency in the range of 1 to 2 GHz. Although the patch antenna 2 has a narrow band characteristic due to its structure, the center of the electromagnetic wave to be received is determined from the longitudinal and lateral dimensions of the receiving electrode 16, the longitudinal and lateral dimensions of the ground electrode 12, and the specifications of the thickness and dielectric constant of the antenna dielectric 13. Frequency, bandwidth, and gain can be designed. Thus, since the patch antenna 2 is formed on one side of the composite multilayer substrate 11 as an antenna for partial discharge detection, a frequency band and a bandwidth effective for partial discharge detection can be configured. In the present embodiment, the center frequency is set to 1.8 GHz and the bandwidth is set to 100 MHz.

  The electromagnetic wave detection circuit 3 includes a circuit pattern formed on the first circuit board 14 and the second circuit board 15 of the composite multilayer substrate 11 and electronic components mounted on the first circuit board 14. The electromagnetic wave detection circuit 3 measures the narrowband signal detected by the patch antenna 2. FIG. 5 shows a block diagram of the electromagnetic wave detection circuit 3. The electromagnetic wave detection circuit 3 includes a bandpass filter (BPF) 60, a low noise amplifier (LNA) 61, a detection circuit 62, a peak hold circuit (P / H circuit) 63, and an analog / digital conversion circuit (A / D conversion circuit) 64. , A data processing circuit 65, a data input / output circuit 66, and a connector 4. Here, the band-pass filter 60 is a noise removing unit that reduces detection signal noise detected by the patch antenna 2, and the low-noise amplifier 61 and the detection circuit 62 are signal amplification that amplifies the detection signal with reduced noise. The peak hold circuit 63 is a peak detection means for detecting the peak value of the amplified detection signal within a predetermined measurement time (measurement time window), and the analog / digital conversion circuit 64 and the data processing circuit 65 are The digital signal processing means digitizes the peak value.

  DC power is supplied from the power source 6 to the electromagnetic wave detection circuit 3 through the composite cable 5. The data processing circuit 65 includes an FPGA (Field Programmable Gate Array) 67, a memory 68, and a CPU (Central Processing Unit) 69. The memory includes a RAM (Random Access Memory) and a ROM (Read Only Memory) (not shown).

  FIG. 6 is a configuration diagram of a high-voltage device that incorporates the partial discharge measuring device 1 and monitors partial discharge. The partial discharge measuring device 1 configured as described above is arranged as shown in FIG. 6 to measure or monitor partial discharge. In FIG. 6, the power distribution device 31 includes a circuit breaker 33, a transformer 34, a power distribution device 35, a power receiving high voltage bus 36, a load side power distribution bus 37, and the like installed inside the power distribution board frame 32. The partial discharge measuring device 1 is installed on the inner wall of the distribution board frame 32 in the vicinity of a high voltage device such as the circuit breaker 33, the transformer 34, and the distribution device 35 with the surface of the patch antenna 2 facing the high voltage device. Yes. Then, DC power is supplied to the partial discharge measuring apparatus 1 by the power source 6 from the outside of the power distribution board frame 32 via the composite cable 5. The power source 6 is configured to supply DC power from a commercial power source 100V using a transformer circuit (not shown) and an A / D converter (not shown). The signal detected by the partial discharge measuring device 1 is output to the detection signal output means 7 via the data input / output circuit 66 and the connector 4. Note that the detection signal output means 7 is installed in a high-voltage device to be measured.

  The detection signal output means 7 includes a digital display 38 and an I / F connector 39. The detection signal output means 7 is connected to the electromagnetic wave detection circuit 3 by the composite cable 5 derived from the electromagnetic wave detection circuit 3, and digitally displays the partial discharge measurement result measured by the electromagnetic wave detection circuit 3. The I / F connector 39 is connected to the monitoring terminal 42 installed in the monitoring center 41 via the communication line 40.

  Next, the operation of partial discharge detection by the partial discharge measuring device 1 will be described. In FIG. 6, high voltage devices such as a circuit breaker 33, a transformer 34, and a power distribution device 35 that constitute the power distribution device 31 are provided with insulators (not shown), and a power reception high voltage bus 36, a load side power distribution bus 37. Is supported by a support insulator (not shown). These insulators, support insulators, and the like are deteriorated due to long-term operation of the power receiving and distributing device 31 and progress. When this insulation deterioration progresses, a partial discharge is generated from the insulator by the operating voltage of the power receiving and distributing device 31, and an electromagnetic wave is emitted along with the generation of the partial discharge. The electromagnetic wave is measured and monitored to monitor the partial discharge occurrence state of the power receiving / distributing device 31.

  The electromagnetic wave accompanying the partial discharge generated in the power distribution board frame 32 is radiated from the partial discharge generation location, but propagates while being irregularly reflected in the power distribution board frame 32 because the power distribution board frame 32 is made of metal. The propagating electromagnetic wave passes through the dielectric casing 19 of the partial discharge measuring device 1 installed on the inner wall of the distribution board frame 32 and reaches the receiving electrode 16 of the patch antenna 2 to be received. Here, the patch antenna 2 is an antenna having directivity. However, even if the installation direction of the patch antenna 2 is not necessarily directed to the location where the partial discharge is generated due to the effect of the irregular reflection described above, the electromagnetic wave accompanying the partial discharge is highly sensitive. Received. The patch antenna 2 receives an electromagnetic wave having a center frequency of 1.8 GHz and a bandwidth of 100 MHz. The received electromagnetic wave is transmitted to the feeder circuit pattern 45 via the feeder line 17. The power feeding circuit pattern 45 is connected to the electromagnetic wave detection circuit 3.

  The received electromagnetic wave has a bandwidth limited to 20 MHz by the bandpass filter 60 of the electromagnetic wave detection circuit 3, and is sent to the low noise amplifier 61, the detection circuit 62, the peak hold circuit 63, the analog / digital conversion circuit 64, and the data processing circuit 65. Are sequentially transmitted and signal processed. Then, by using the low noise amplifier 61 and the detection circuit 62 which is a log detection circuit, it is possible to detect a partial discharge in a wide range of −90 dBm to −30 dBm. By performing signal processing on the received electromagnetic wave, the generated partial discharge can be detected as a partial discharge pulse. At the stage where the insulation deterioration of the insulator, the support insulator, etc. has progressed, the number of partial discharge pulses is from several thousand to several tens of thousands per second, and the discharge intensity varies randomly in the range of -90 dBm to -30 dBm. While these many partial discharge pulses are generated, there is a correlation between the insulation deterioration and the partial discharge intensity, and it was found that the partial discharge caused by the progress of the insulation deterioration has a high discharge intensity. ing.

  In the data processing circuit 65, the maximum pulse of the detection signal is measured for each measurement time window which is a set detection window, and the partial discharge occurrence time and the maximum discharge intensity of the partial discharge pulse are calculated and recorded from the maximum pulse. . The measurement time window in this embodiment is 30 μsec. When a plurality of partial discharge pulses accompanying partial discharge are generated in the measurement time window of 30 μsec, the maximum discharge intensity of the partial discharge pulse during 30 μsec is recorded. In the present embodiment, the measurement time window is set to 30 μs. However, even when the measurement time window range is set to 5 μs to 250 μs, the partial discharge occurrence time and the maximum discharge intensity of the partial discharge pulse can be calculated. it can.

  The data processing circuit 65 is designed so that the measurement result can be output effectively so that the progress of the insulation deterioration of the insulator can be grasped. That is, the data processing circuit 65 controls the measurement time as set by the measurer. The measurement time in the present embodiment can be arbitrarily set from 1 second to 30 seconds. In this embodiment, the measurement time window is set to 30 μs and the measurement time is set to 1 to 30 seconds. However, the measurement time window and the measurement time can be arbitrarily designed, and the data transfer time for remote monitoring is taken into consideration. It is good to design. The measurement data processed by the data processing circuit 65 is the discharge occurrence time, discharge intensity, maximum discharge intensity, partial discharge occurrence cumulative frequency distribution, and partial discharge occurrence phase-intensity-frequency characteristics of each pulse. The discharge occurrence time is a phase with respect to the voltage applied to the power receiving / distributing device 31. The maximum discharge intensity is an intensity level at which partial discharge occurs in each cycle of the applied voltage. A large number of measurement data processed by the data processing circuit 65 is stored in a memory 68 in the data processing circuit 65. In this way, by providing the measurement time window and measuring only the maximum value in the measurement time window, it is possible to selectively detect a pulse useful for determining insulation deterioration. And by selectively detecting in the measurement time window, the amount of data for partial discharge monitoring can be reduced, and the data transfer time can be shortened. Therefore, effective remote monitoring for monitoring a large number of high voltage devices can be performed.

  The measurement data processed by the data processing circuit 65 is output to the detection signal output means 7 via the data input / output circuit 66. The detection signal output means 7 displays the maximum discharge intensity on the digital display 38 and transmits measurement data to the monitoring terminal 42 via the I / F connector 39 and the communication line 40. The monitoring terminal 42 displays measurement results and stores / accumulates data to manage secular changes.

  7 and 8 are examples of measurement results of partial discharge of the power receiving and distributing device 31 displayed on the monitoring terminal 42. FIG. FIG. 7 shows the discharge generation phase characteristics, and FIG. 8 shows the generation frequency distribution and the maximum discharge intensity. 7 and 8 show the results of the same measurement data, and the measurement conditions are a measurement time window of 30 μs and a measurement time of 3 seconds. As shown in FIG. 7, partial discharge can be measured with high sensitivity up to -90 dBm. As described above, the monitoring center 41 can analyze the detailed data by the monitoring terminal 42. On the other hand, by installing a digital display 38 on the surface of the power distribution device 31 and displaying the maximum discharge intensity at all times, the monitoring status can be grasped at the site where the power distribution device 31 is installed. And the equipment operator can grasp the deterioration of the insulator.

  As described above, since electromagnetic wave noise can be prevented from entering the electromagnetic wave detection circuit 3 by covering the electromagnetic wave detection circuit 3 from both sides with the electromagnetic wave shielding housing 18 and the ground electrode 12, the detection sensitivity of partial discharge can be increased. Further, since the transmission distance from the patch antenna 2 to the electromagnetic wave detection circuit 3 is minimized, the signal attenuation of the electromagnetic wave accompanying the partial discharge can be minimized, and highly sensitive partial discharge detection can be performed. Furthermore, by providing the patch antenna 2 and the electromagnetic wave detection circuit 3 on the front and back of the same composite multilayer substrate 11, a small and inexpensive partial discharge measuring device 1 can be manufactured. Moreover, since the moisture resistance and the dust proof characteristic are improved by covering the patch antenna 2 and the electromagnetic wave detection circuit 3 with the dielectric case 19 and the electromagnetic wave shielding case 18 with the packing 20, the long-term reliability of the partial discharge measuring device 1 is improved. Get higher. Furthermore, since the partial discharge intensity value can always be displayed on the outer surface of the power receiving / distributing device 31 during operation, a patrol inspector or device driver who is not a monitoring specialist can grasp the deterioration state of the insulator.

  In the present embodiment, the design of the center frequency, bandwidth, and gain of the electromagnetic wave received by the patch antenna 2 has been described for the case where the reception electrode is rectangular, but it goes without saying that the reception electrode can be designed similarly even if it is circular. No. Moreover, although the feed line 17 of the patch antenna 2 has been shown to be connected to the electromagnetic wave detection circuit 3 through the through hole 23, the feed line 17 and the electromagnetic wave detection circuit 3 may be connected at the shortest distance. It is not limited to a through hole, but may be a pin or a circuit pattern.

Embodiment 2. FIG.
FIG. 9 is a perspective view of a partial discharge measuring apparatus showing Embodiment 2 for carrying out the present invention. In FIG. 9, the patch antenna 2 and the electromagnetic wave detection circuit 3 are connected to each other by a through hole that penetrates the receiving electrode of the patch antenna instead of the feeder line. 9, the same reference numerals as those in FIG. 2 denote the same or corresponding parts, and this is common throughout the entire specification. Moreover, the aspect of the component which appears in the whole specification is an illustration to the last, and is not limited to these description.

  FIG. 10 shows a partial cross-sectional view of the composite multilayer substrate 11. A through hole 80 is formed in the composite multilayer substrate 11. In the first embodiment, the through hole is formed in a region where the receiving electrode 16 of the patch antenna 2 is not formed. However, in the present embodiment, the through hole 80 is formed in the receiving electrode 16. The through hole 80 is formed so as to penetrate from the receiving electrode 16 to the power feeding circuit pattern 45 of the electromagnetic wave detection circuit 3. By forming the through hole 80, the wiring distance between the receiving electrode 16 and the power feeding circuit pattern 45 of the electromagnetic wave detection circuit 3 is configured to be the shortest.

  Thus, by forming the through hole 80 through the receiving electrode 16, the wiring between the patch antenna 2 and the electromagnetic wave detection circuit 3 can be shortened, so that the signal attenuation of the electromagnetic wave due to the partial discharge can be reduced. The partial discharge detection sensitivity can be increased.

Embodiment 3 FIG.
FIG. 11 is a cross-sectional view showing a configuration of a partial discharge measuring apparatus showing Embodiment 3 for carrying out the present invention. In FIG. 11, the configuration of the partial discharge measurement device 71 is different from the configuration of the first embodiment in that the patch antenna 2 and the electromagnetic wave detection circuit 3 are installed on the same surface of the substrate 52.

  In the present embodiment, a planar electrode 55 is formed on the substrate 52. The electromagnetic wave detection circuit 3 and the planar electrode 55 are insulated, and the electromagnetic wave detection circuit 3 is installed in a region corresponding to the region where the planar electrode 55 is formed. The planar electrode 55 may be formed on a surface opposite to the surface on which the electromagnetic wave detection circuit 3 is installed as in the present embodiment, or may be formed on any layer of the composite multilayer substrate. The electromagnetic wave detection circuit 3 is covered with an electromagnetic wave shielding casing 54 that shields electromagnetic waves. The patch antenna 2 is protected by a dielectric casing 53. Further, since the electromagnetic wave detection circuit 3 and the patch antenna 2 are installed on the same substrate, the input / output terminals of the electromagnetic wave detection circuit 3 and the input / output terminals of the patch antenna 2 are arranged in the vicinity, and a short feeder is wired. That's fine.

  With such a configuration, the electromagnetic wave detection circuit 3 is covered from both surfaces by the electromagnetic wave shielding casing 54 and the flat electrode 55 that shield the electromagnetic wave, so that intrusion of electromagnetic wave noise to the electromagnetic wave detection circuit 3 can be prevented. The detection sensitivity can be increased. Further, although the entire device is slightly larger, it is not necessary to provide a through hole in the substrate, and the transmission distance from the patch antenna 2 to the electromagnetic wave detection circuit 3 can be easily shortened. For this reason, the signal attenuation of the electromagnetic wave accompanying partial discharge can be made small.

Embodiment 4 FIG.
FIG. 12 is a cross-sectional view showing a configuration of a partial discharge measuring apparatus showing Embodiment 4 for carrying out the present invention. FIG. 13 is a perspective view of the partial discharge measuring apparatus shown in FIG. 12 as viewed from the electromagnetic shielding housing side. In FIG. 12, the configuration of the partial discharge measuring device 72 is different from the configuration of the first embodiment in that the magnet 51 is fixed to the back surface of the electromagnetic wave shielding housing 18 by adhesion.

  The magnets 51 are installed at the four corners on the back surface of the electromagnetic wave shielding casing 18. Since the magnet 51 is installed on the back surface of the electromagnetic wave shielding casing 18, the magnet 51 can be used to easily fix the metal inner wall surface of the monitoring target device such as the power receiving / distributing device 31. The number of magnets 51 installed on the back surface of the electromagnetic wave shielding casing 18 is not limited to four, and may be any number. In addition, although the case where the magnet was fixed by adhesion | attachment was demonstrated, it is not limited to the fixation by adhesion | attachment.

  Moreover, like the partial discharge measuring device 73 shown in FIG. 14, the electromagnetic wave shielding housing 18b may be provided with a recess, and the magnet 51b may be installed by fitting into the recess. With such a configuration, protrusions from the metal inner wall when installed on the metal inner wall are reduced, and an insulating safety distance from the high voltage portion can be secured. The magnet 51b is fixed to the electromagnetic shielding casing 18b by adhesion. However, by using a magnetic material such as iron for the electromagnetic shielding casing 18b, the magnet 51b is fixed to the electromagnetic shielding casing 18b by the magnetic force of the magnet 51b. Also good.

  Normally, power distribution equipment in buildings and factories is always in operation, and power outages cannot be made due to insulation testing and insulation monitoring equipment installation. On the other hand, distribution boards that require insulation testing and insulation monitoring are devices that operate for a long period of time and are subject to deterioration. Such equipment is in operation and requires insulation testing and monitoring without power failure. With the configuration of the present embodiment, there is no need for a power failure even during operation of the power receiving / distributing device, and the door of the power receiving / distributing device can be opened and easily installed on the inner wall.

It is sectional drawing which shows the structure of the partial discharge measuring device which shows Embodiment 1 of this invention. It is a perspective view of the partial discharge measuring device in Embodiment 1 of this invention. It is a perspective view of the partial discharge measuring device in Embodiment 1 of this invention. It is a fragmentary sectional view of the composite multilayer substrate in Embodiment 1 of this invention. It is a block diagram of the electromagnetic wave detection circuit in Embodiment 1 of this invention. It is a block diagram of the high voltage apparatus which incorporates the partial discharge measuring device in Embodiment 1 of this invention, and monitors partial discharge. It is a measurement result of the partial discharge in Embodiment 1 of this invention. It is a measurement result of the partial discharge in Embodiment 1 of this invention. It is a perspective view of the partial discharge measuring device which shows Embodiment 2 of this invention. It is a fragmentary sectional view of the composite multilayer substrate in Embodiment 2 of this invention. It is sectional drawing which shows the structure of the partial discharge measuring device which shows Embodiment 3 of this invention. It is sectional drawing which shows the structure of the partial discharge measuring device which shows Embodiment 4 of this invention. It is a perspective view of the partial discharge measuring device in Embodiment 4 of this invention. It is sectional drawing which shows the structure of another partial discharge measuring device which shows Embodiment 4 of this invention.

Explanation of symbols

  1, 71, 72, 73 Partial discharge measuring device, 2 patch antenna, 3 electromagnetic wave detection circuit, 4 connector, 5 composite cable, 6 power supply, 7 detection signal output means, 11 composite multilayer substrate, 12 ground electrode, 13 antenna dielectric , 14 1st circuit board, 15 2nd circuit board, 16 Reception electrode, 17 Feed line, 18, 18b, 54 Electromagnetic wave shielding housing, 19, 53 Dielectric housing, 20 Packing, 21 Screw, 22 Airtight terminal, 23 , 80 Through hole, 25 Screw hole, 26 Packing groove, 31 Power distribution device, 32 Power distribution panel frame, 33 Circuit breaker, 34 Transformer, 35 Power distribution device, 36 Power receiving high voltage bus, 37 Load side power distribution bus, 38 Digital display , 39 I / F connector, 40 communication line, 41 monitoring center, 42 monitoring terminal, 45 feeding circuit pattern, 46 detection Route pattern, 47 Second circuit pattern, 51, 51b Magnet, 52 Substrate, 55 Planar electrode, 60 Band pass filter, 61 Low noise amplifier, 62 Detection circuit, 63 Peak hold circuit, 64 Analog / digital conversion circuit, 65 Data processing Circuit, 66 data input / output circuit, 67 FPGA, 68 memory, 69 CPU.

Claims (9)

An antenna for detecting electromagnetic waves radiated with partial discharges caused by insulation deterioration of electrical equipment;
An electromagnetic wave detection circuit for measuring a partial discharge based on a detection signal from the antenna;
A substrate on which the antenna and the electromagnetic wave detection circuit are installed, and a planar electrode insulated from the electromagnetic wave detection circuit is formed;
The partial discharge measuring device, wherein the electromagnetic wave detection circuit is installed in an area corresponding to an area where the planar electrode is formed and is covered with an electromagnetic wave shielding body that shields the electromagnetic wave. The partial discharge measuring apparatus according to claim 1, wherein an area of the electromagnetic shielding body facing the substrate is larger than an area of the planar electrode. 3. The partial discharge measuring apparatus according to claim 1, wherein the antenna is a patch antenna having a detection center frequency in a range of 1 to 2 GHz constituted by a ground electrode, an antenna dielectric, and a receiving electrode. . The electromagnetic wave detection circuit is installed on one surface of the substrate,
The partial discharge measuring apparatus according to claim 3, wherein the antenna is installed on the other surface of the substrate, and the planar electrode serves as the ground electrode. A feed line for connecting the electromagnetic wave detection circuit and the antenna;
The partial discharge measuring apparatus according to claim 4, wherein a part of the feeder line is configured by a through hole provided in the substrate. The electromagnetic wave detection circuit includes a noise removing unit that reduces noise of the detection signal, a signal amplification unit that amplifies the detection signal with reduced noise, and a peak value of the amplified detection signal within a predetermined measurement time. The partial discharge measuring apparatus according to claim 1, further comprising: a peak detecting unit that performs digital signal processing that digitizes the peak value. The electromagnetic wave detection circuit has a detection intensity range of the electromagnetic wave set to -90 dBm to -30 dBm, a detection bandwidth of the electromagnetic wave is set to 20 MHz, and a detection window range of the electromagnetic wave is set to 5 μsec to 250 μsec, The partial discharge according to claim 1, wherein the maximum pulse of the detection signal in the electromagnetic wave detection window is measured, and the maximum discharge intensity of the partial discharge is calculated from the maximum pulse. Measuring device. A detection signal output means connected to the electromagnetic wave detection circuit and installed in the electrical equipment;
The partial discharge measuring apparatus according to claim 1, wherein the detection signal output unit digitally displays a measurement result of the partial discharge measured by the electromagnetic wave detection circuit. The partial discharge measuring apparatus according to claim 1, further comprising a magnet installed on an outer surface of the electromagnetic shielding body.

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