JP2006058166A - Partial discharge detecting unit and detecting method for rotary electrical equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify and facilitate attaching noncontactly to detect a partial discharge signal in high-voltage rotary electric equipment and to diagnose insulation. <P>SOLUTION: This detecting unit is provided with a metal frame 5 connected to a stator frame 7 of the rotary electric equipment, an electric power line or a neutral point extraction wire 4 arranged inside the metal frame and for propagating the partial discharge signal generated by deterioration of a stator coil 6, a sensor 1 installed in the peripheral part of the electric power line or neutral point extraction wire arranged inside the metal frame, and comprising a rod-like antenna or a loop-like antenna with the partial discharge signal propagated to the electric power line or the neutral point extraction wire 4 electrostatically or electromagnetically induced, and a detector 3 for fetching a signal generated in the sensor 1 through a signal extraction line 2 to detect the partial discharge signal by signal processing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a partial discharge detection device and a detection method for a rotating electrical machine.

  In a high-voltage rotating electrical machine, when it is operated for a long period of time, the electrical insulator inside the equipment deteriorates due to electrical, thermal, mechanical and environmental stresses, and eventually leads to dielectric breakdown and eventually equipment failure. Sometimes.

  Therefore, in a high-voltage rotating electrical machine, it is necessary to monitor and diagnose insulation deterioration inside the device from the viewpoint of improving the reliability of the device and operation management. In particular, since the stator coil of a rotating electrical machine has a large electrical, thermal and mechanical stress, it is important to monitor and diagnose the insulation deterioration of the stator coil.

  By the way, as a method for detecting the deterioration of the insulator of the stator coil, there is a method of detecting a pulsed partial discharge signal generated due to the deterioration of the insulation of the coil, but the partial discharge generated in the coil inside the rotating electric machine is directly detected. It is difficult to detect.

  For this reason, conventionally, a detection sensor is housed inside the stator coil (for example, Patent Document 1), or a detection sensor is attached to an end space inside the rotating electrical machine, so that the interior of the rotating electrical machine can be accommodated with the occurrence of partial discharge. There are some which detect an electromagnetic wave propagating, an electric pulse signal flowing through a coil, a coil connection line and a power line.

  However, this detection method has the advantages of high detection sensitivity and noise reduction because the position of the partial discharge generation source and the sensor is the closest, but on the other hand, it takes time to install the sensor, such as pulling out the coil. There was a problem that it was difficult to install.

  In particular, for rotating electrical machines that have been operating for several decades, there is a high need for diagnosis of insulation deterioration, and therefore, a partial discharge detection sensor that is easy to attach to these existing rotating electrical machines is required.

  Therefore, there is one that detects a partial discharge signal by connecting a direct detection sensor such as an electrostatic capacitor or a current transformer to a high voltage charging unit such as a stator coil in a rotating electric machine or a power line connected to the rotating electric machine (for example, Patent Document 2).

  However, while this detection method has an advantage of high detection sensitivity, there is a problem in that high electrical insulation stress is directly applied to the detection sensor, so that the sensor itself is required to have high insulation performance.

  Furthermore, there is a type that detects a radiated electromagnetic wave by partial discharge or a partial discharge by electrostatic coupling without contact with a high voltage power line at the end of a stator coil inside the rotating electrical machine frame (Patent Document 3).

However, in this detection method, since it is necessary to mount the detection sensor inside the rotating electrical machine, there is a problem that mounting work such as gas replacement inside the rotating electrical machine frame is troublesome.
JP-A-4-299048 JP-A-4-299050 JP 2000-346916 A

  As described above, any of the conventional partial discharge detection methods has a problem that it takes a lot of labor and time to install the detection sensor, and further, there is a problem that a high insulation performance is required for the sensor itself.

  The present invention has been made in view of these points, and it is an object of the present invention to provide a partial discharge detection device and a detection method thereof that can be easily attached to a high voltage portion without contact.

  The invention corresponding to claim 1 is a metal frame connected to a stator frame of a rotating electrical machine, and a power line or neutral that is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil. A sensor comprising a point lead wire and a rod or loop antenna that is installed around the conductive wire in the metal frame and in which a partial discharge signal propagated to the power line or neutral point lead wire is electrostatically and electromagnetically induced And a detector that takes in a signal generated in the sensor through a signal lead line and detects partial discharge by signal processing.

  According to a second aspect of the present invention, there is provided a metal frame connected to a stator frame of a rotating electric machine, and a power line or neutral that is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil. A point leader and one end where a partial discharge signal that is disposed around the power line or neutral point leader in the metal frame and propagates to the power line or neutral point leader is electrostatically and electromagnetically induced is electrically connected A sensor composed of a plurality of rod-shaped antennas connected to, and a detector that detects a partial discharge through signal processing by taking a signal generated in the sensor through a signal lead line.

  According to a third aspect of the present invention, the partial discharge signal generated by the deterioration of the stator coil installed at the end of the stator coil inside the stator frame of the rotating electrical machine or around the coil connecting conductor is electrostatic and electromagnetic induction. A sensor comprising a plurality of rod-shaped antennas, one end of which is electrically connected, and a detector for detecting a partial discharge by signal processing by taking a signal generated in the sensor through a signal lead line.

  According to a fourth aspect of the present invention, there is provided a metal frame connected to a stator frame of a rotating electric machine, and a power line or neutral that is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil. Electrostatic and electromagnetic induction is applied to the partial discharge signal that is arranged in series around the leader line and the periphery of the power line or neutral point leader line in the metal frame and propagates to the power line or neutral point leader line. And a sensor that takes in a signal generated in the sensor through a signal lead line and detects a partial discharge by signal processing.

  According to a fifth aspect of the present invention, there is provided a metal frame connected to a stator frame of a rotating electrical machine, and a power line or neutral that is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil. A point leader, a cylindrical or arc-shaped electrode concentrically arranged on the power line or neutral point leader in the metal frame and having electrostatic coupling with the power line or neutral point leader, and the electrode and metal When the partial discharge signal is propagated to the resistor connected between the frames or between the electrode and the ground, and the power line or the neutral point lead line, a high-frequency current flowing through the resistor is taken in from the electrode and is partially processed by signal processing. And a detector for detecting discharge.

  According to a sixth aspect of the present invention, there is provided a metal frame connected to a stator frame of a rotating electrical machine, and a power line or neutral that is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil. A point leader, a cylindrical or arc-shaped electrode concentrically arranged on the power line or neutral point leader in the metal frame and having electrostatic coupling with the power line or neutral point leader, and the electrode and metal A high-frequency current transformer provided in a connection line connected between the frames or between the electrode and the ground, and a high-frequency current flowing through the connection line when a partial discharge signal is propagated to the power line or neutral lead-out line And a detector that takes in from the current transformer and detects partial discharge by signal processing.

  The invention corresponding to claim 7 is a rotating electrical machine provided with the partial discharge detection device of the invention corresponding to any one of claims 1 to 6.

  The invention corresponding to claim 8 is provided with a power line or a neutral point lead line for propagating a partial discharge signal generated by deterioration of the stator coil in a metal frame connected to a stator frame of a rotating electrical machine, Two sensors each consisting of a rod-shaped antenna, a loop-shaped antenna, or a plurality of rod-shaped antennas with one end electrically connected to each other at a predetermined distance in at least two locations for each phase of the power line or neutral lead-out line The stator coils are compared by comparing the arrival time differences of the output signal waveforms obtained through the two signal leaders having the same or known differences connected to the two sensors in phase with each other. A partial discharge signal generated by deterioration is detected.

  The invention corresponding to claim 9 is provided with a power line or a neutral point lead line for propagating a partial discharge signal generated by deterioration of the stator coil in a metal frame connected to a stator frame of a rotating electrical machine, One of two sensors consisting of a rod-shaped antenna, a loop-shaped antenna, and a plurality of rod-shaped antennas electrically connected at one end is connected to the end of the stator coil inside the stator frame or to the stator coil Installed around the conductor, and installed the other around the power line or neutral lead line in the metal frame at a predetermined distance from the one sensor, and connected to the two sensors, respectively. A partial discharge signal generated by deterioration of the stator coil is detected by comparing the arrival time differences of output signal waveforms obtained through two signal leaders having the same or known difference in length.

  The invention corresponding to claim 10 arranges a power line or a neutral point lead line that propagates a partial discharge signal generated by deterioration of the stator coil in a metal frame connected to a stator frame of a rotating electrical machine, Two sensors consisting of a loop antenna or a plurality of loop antennas connected in series around the power line or neutral lead line in the metal frame are installed at a predetermined distance, and each sensor Arrange the output pulse waveform of the connected signal leader line so that the polarities of the peak values are opposite to each other, or wire the signal leader line from each sensor, and place the power line or neutral point in the direction of entering the rotating electrical machine. A pulse signal output to a signal lead line terminal connected to a sensor away from the stator coil side induced by an electric pulse signal propagating through the lead line is the power line or medium The length of the signal leader line of each sensor so as to reach the same time as the pulse signal output to the signal leader terminal connected to the sensor on the stator coil side induced by the same pulse signal flowing through the point leader line The partial discharge signal generated by the deterioration of the stator coil is detected from the sum of pulse waveforms obtained through these two signal lead lines.

  The invention corresponding to claim 11 arranges a power line or a neutral point lead line for propagating a partial discharge signal generated by deterioration of the stator coil in a metal frame connected to a stator frame of a rotating electrical machine, One of two sensors consisting of a loop antenna or a plurality of loop antennas connected in series is installed at the end of the stator coil inside the stator frame or around the stator coil connection conductor, and the other is Installed around the power line or neutral point leader in the metal frame with a predetermined distance from one sensor, and the polarity of the peak value of the output pulse waveform of the signal leader connected to each sensor Arrange the signal leaders from each sensor so that they are opposite to each other, or wire the signal lead lines from each sensor to the electrical pulse signal that propagates the power line or neutral point leader line in the direction of entering the rotating electrical machine. The stator coil in which a pulse signal output to a signal lead terminal connected to a sensor remote from the stator coil side induced by the same pulse signal flowing through the power line or neutral point lead line is induced The length of the signal lead line of each sensor is adjusted so as to reach the same time as the pulse signal output to the signal lead terminal connected to the sensor on the side, and the pulse waveform obtained through these two signal lead lines The partial discharge signal generated by the deterioration of the stator coil is detected from the sum of the above.

  The invention corresponding to claim 12 is provided on the inner surface or outer surface of the stator frame of the rotating electrical machine or the inner surface or outer surface of the metal frame connected to the stator frame of the rotating electrical machine and provided with a power line or neutral lead line inside. A microstrip antenna composed of a conductor flat plate, an insulating plate, and a transmission line, one side of which is connected to a termination resistor, is installed, and a partial discharge generated due to deterioration of the stator coil causes a stator coil to the stator frame or the power line. Alternatively, a partial discharge of the stator coil is detected by processing a current signal output from the microstrip antenna by an electromagnetic wave propagating in a space between the metal frames from a neutral lead line.

  According to a thirteenth aspect of the present invention, a plurality of microstrip antennas each including a conductor flat plate, an insulating plate, and a transmission line, one side of which is connected to a terminating resistor, are installed inside a stator frame of a rotating electrical machine. A partial discharge generation source is specified by comparing the signal intensity output from each of the microstrip antennas by an electromagnetic wave propagating from the stator coil through the space between the stator frames due to the partial discharge generated by the deterioration of the coil.

  The partial discharge detection device and the detection method according to the present invention can detect and insulate the partial discharge signal of a high-voltage rotating electrical machine by making contactless and easy installation without contact, and can make an appropriate repair plan for the high-voltage rotating electrical machine. It can greatly contribute to development and improvement of reliability.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram of a partial discharge detection device for a rotating electrical machine showing a first embodiment of the present invention.

  In FIG. 1, a stator coil 6 of a rotating electrical machine is accommodated in a slot provided in a stator core (not shown) attached to the inner peripheral surface of a stator frame 7.

  A cylindrical metal frame 5 is attached to the stator frame 7, and a power line or a neutral lead-out line 4 is supported on an insulating support (not shown) on the stator coil 6 on the central axis in the metal frame 5. In addition, the rod-shaped antenna 1 made of an electrically conductive material is installed as a sensor in a non-contact manner on the power line or the neutral point lead line 4.

  In this case, the rod-shaped antenna 1 is arranged in parallel to the power line or neutral lead line 4 as shown in FIG. Fixed to.

  A signal lead wire 2 is connected to one end of such a rod-shaped antenna 1, and a partial discharge pulse inputted through the signal lead wire 2 is sent to the detector 3 via a resistor or a high-frequency current transformer (not shown). It is taken in. In this case, the partial discharge pulse input to the detector 3 is amplified by a signal amplification preamplifier as necessary.

  As shown in FIG. 3, the detector 3 includes an analog signal processing circuit 54 including a comparison circuit 51, a gate 52, an arithmetic circuit 53 such as an integration circuit and a peak detection circuit, and a wave output from the analog signal processing circuit 54. A display device 55 for displaying a high value, an analog / digital conversion circuit 56 for digitally converting the integral value output from the analog signal processing circuit 54, and a storage device 57 for storing the output of the analog / digital conversion circuit 56 are provided. Yes.

  In the partial discharge pulse detecting device having such a configuration, when a partial discharge occurs due to insulation deterioration of the stator coil 6, the partial discharge signal is propagated to the power line or the neutral lead-out line 4.

  This partial discharge signal is electrostatically and electromagnetically induced from the power line or neutral point lead line 4 to the rod-shaped antenna 1 and is taken from the signal lead line 2 to the detector 3 via a resistor or a high-frequency current transformer.

  In this detector 3, the comparison circuit 51 compares the determined threshold value 62 with the signal waveform value 61 as shown in FIG. 4, and ignores signals below the threshold value. For a signal exceeding the value, a certain time 63 is taken in by the gate 52, and for example, a peak value 64 first appearing within that time is detected as a partial discharge magnitude (integrated value) 65 by the peak detection circuit 53, and the waveform of the oscilloscope is obtained. While being displayed on the display device 55 such as an observation device or a recorder, the peak value and the like are digitally converted by the analog / digital conversion circuit 56 and stored in the storage device 57.

  FIG. 5 shows an example of the waveform displayed on the waveform observer by detecting the partial discharge pulse propagating through the power line or the neutral lead line 4 with the rod-shaped antenna 1 and the detector 3. As shown in FIG. 5, the pulse signal 31 propagating through the power line or the neutral point lead line 4 induces a pulse waveform 32 having a first wave of the same polarity as the first wave of the propagation pulse of the conductive line in the antenna. .

  Therefore, by observing a pulse waveform having the same polarity as the first wave displayed on the waveform monitor, it can be seen that partial discharge is generated in the stator coil.

  In this way, the rod-shaped antenna 1 is installed as a sensor in a non-contact manner corresponding to the power line or the neutral lead-out line 4 that is connected to the stator coil 6 in the metal frame 5, and the power line or neutral Since the partial discharge signal electrostatically and electromagnetically induced to the rod-shaped antenna 1 from the lead-out line 4 is taken into the detector 3 so that the partial discharge signal generated by the deterioration of the stator coil can be detected. There is no need to process the sensor, and the sensor can be attached to the high voltage portion in a non-contact and relatively simple and easy manner simply by modifying the stator frame around the power line of the rotating electrical machine or the neutral point lead line 4.

  In the above embodiment, in the case where the power line disposed in the metal frame 5 or the power line connected to the stator coil 6 is the neutral point lead line 4, a high voltage is applied to the antenna. It is necessary to alleviate electric field concentration by covering with an insulating material or treating the end of the antenna.

  In the above embodiment, the rod-shaped antenna 1 is used as a sensor. However, as shown in FIG. 6, even when the loop-shaped antenna 9 is used, the portion that is electrostatically and electromagnetically induced from the power line or the neutral lead-out line 4 as described above. A discharge signal can be detected.

  Moreover, in the said embodiment, although the rod-shaped antenna 1 or the loop-shaped antenna 9 was installed in parallel with respect to the power line or the neutral leader line 4, you may arrange | position vertically.

  FIG. 7A is an axial sectional view of a partial discharge detecting device for a rotating electrical machine showing a second embodiment of the present invention, and FIG. 7B is a radial sectional view, which is the same as that of FIG. 1 and FIG. A description will be given with reference numerals.

  In the second embodiment, as shown in FIGS. 7 (a) and 7 (b), the power line or the neutral point lead line 4 is centered using a plurality of rod-shaped antennas 1 as sensors along the inner peripheral surface of the metal frame 5. Are arranged at equal intervals in a circle, and these are supported by an insulating member 8 for supporting the sensor fixed to the metal frame 5. One end of each of these rod-shaped antennas 1 is connected in common by a connection conductor 10, and this connection conductor 10 is connected to a detector 3 through a signal lead wire 2.

  Here, FIG. 8 shows the relationship between the number of rod-shaped antennas and detection sensitivity = (the first peak value of the detection waveform of the sensor) / (the first peak value of the waveform propagating through the power line or neutral lead line). Show.

  The detection sensitivity is 1 when the number of rod-shaped antennas is one.

  As is apparent from the graph shown in FIG. 8, the output of the sensor tends to increase as the number of rod-shaped antennas 1 increases, and the detection sensitivity of the sensor increases when a plurality of rod-shaped antennas are arranged rather than one rod-shaped antenna. I understand.

  With such a configuration, it is not necessary to process the inside of the rotating electrical machine as in the first embodiment, and a high voltage can be obtained simply by remodeling the stator frame around the power line or neutral point lead line of the rotating electrical machine. In addition to being able to attach the sensor to the part without contact relatively easily and easily, the detection sensitivity can be increased.

  In the above embodiment, the case where a plurality of rod-shaped antennas 1 are arranged in a circle has been described. However, as shown in FIG. (The lower half shown in the figure) or straight (the upper half shown in the figure), or as shown, the upper half is linear and the lower half is arcuate, or these are arranged in the opposite direction. An effect can be obtained.

  7 and 9, the plurality of rod-shaped antennas 1 are arranged as sensors in the metal frame 5 connected to the stator frame of the rotating electrical machine. Alternatively, the partial discharge may be detected by non-contact arrangement in the vicinity of the coil connection conductor.

  With such a configuration, in addition to obtaining the same effect as the first embodiment, the antenna is close to the stator coil that is the partial discharge generation source, so that the detection sensitivity of the partial discharge can be improved. it can. In this case, since the rod-shaped antennas are electrically insulated in the commercial frequency band except for the joints at the ends, the loss due to the eddy current generated in the sensor is small even in the region where the magnetic field inside the rotating electrical machine is strong. It is considered to be.

  FIG. 10 (a) is an axial sectional view of a partial discharge detector for a rotating electrical machine showing a third embodiment of the present invention, and FIG. 10 (b) is a radial sectional view. To explain.

  10 (a) and 10 (b), the stator coil 6 of the rotating electrical machine is housed in a slot provided in a stator iron core (not shown) attached to the inner peripheral surface of the stator frame 7.

  A cylindrical metal frame 5 is attached to the stator frame 7, and a power line or a neutral lead-out line 4 is supported on an insulating support (not shown) on the stator coil 6 on the central axis in the metal frame 5. In addition, a cylindrical electrode 11 electrostatically coupled to the power line or neutral point lead line 4 is disposed concentrically around the power line or neutral point lead line 4. In this case, the electrode 11 is fixed to an electrode support insulating member 12 attached to an appropriate location on the inner peripheral surface of the metal frame 5.

  A resistor 13 is connected between the electrode 11 and the metal frame 5 as shown in FIGS. 11A and 11B, and a signal lead wire 2 is connected to the electrode side end of the resistor 13. The high-frequency current due to the partial discharge pulse flowing through the signal lead-out line 2 is taken into the detector 3 via a resistor or a current transformer (not shown). In this case, the partial discharge pulse input to the detector 3 is amplified by a signal amplification preamplifier as necessary.

  Since the detector 3 has the same configuration as that shown in FIG. 3 described in the first embodiment, the description thereof is omitted here.

  In the partial discharge pulse detecting device having such a configuration, when a partial discharge occurs due to insulation deterioration of the stator coil 6, the partial discharge signal is propagated to the power line or the neutral lead-out line 4.

  When this partial discharge signal is propagated to the power line or neutral point lead line 4, the resistor 13 connected between the electrode 11 having electrostatic coupling to the power line or neutral point lead line 4 and the metal frame 5. A high-frequency current of several kHz or more of the partial discharge signal flows through this, and this high-frequency current is taken into the detector 3 from the signal line 2 via a resistor or a current transformer (not shown).

  The detector 3 can detect an optimum high frequency band signal by the same signal processing as described in the first embodiment.

  FIG. 12 shows a partial discharge pulse 33 propagating through the power line or neutral point lead line 4 and a waveform 34 detected by the resistor 13 connected to the electrode 11 arranged concentrically with respect to the power line or neutral point lead line 4. Show.

  As is apparent from FIG. 12, a first wave having the same polarity as the first wave of the propagation pulse of the conductor is applied to the detection circuit composed of the electrode 11 and the resistor 13 by the pulse signal 33 propagating through the power line or the neutral lead line 4. It can be seen that a pulse waveform 34 is induced.

  Therefore, by observing a pulse waveform having the same polarity as the first wave displayed on the waveform monitor, it can be seen that partial discharge is generated in the stator coil.

  Thus, the cylindrical electrode 11 that is electrostatically coupled to the power line or the neutral point lead line 4 disposed in the metal frame 5 connected to the stator coil 6 is centered on the power line or the neutral point lead line 4. This is caused by deterioration of the stator coil by concentrically installing the high-frequency current flowing through the resistor 13 connected between the electrode 11 and the metal frame 5 (earth) into the detector 3 for signal processing. Since the partial discharge signal can be detected, there is no need to process the inside of the rotating electrical machine, and the sensor can be connected to the high-voltage part in a non-contact manner simply by remodeling the stator frame around the power line or neutral point lead wire of the rotating electrical machine. It can be installed relatively easily and easily.

  In the above embodiment, the high-frequency current flowing through the resistor 13 connected between the electrode 11 and the metal frame 5 (earth) is taken into the detector 3, but as shown in FIGS. 13 (a) and 13 (b). A high-frequency current transformer 14 is provided on the connecting conductor connecting the electrode 11 and the metal frame 5 (ground) to the detector 3, and the high-frequency current detected by the high-frequency current transformer 14 is input to the detector 3. good.

  Moreover, in the said embodiment, although the cylindrical electrode 11 which carries out electrostatic coupling with the power line or the neutral point lead line 4 was arrange | positioned concentrically centering on the power line or the neutral point lead line 4, FIG. , (B), the cylindrical electrode 11 is divided into a plurality of pieces in the axial direction and divided electrodes 15 formed in an arc shape are arranged concentrically around the power line or the neutral lead line 4. Also good. In this case, a plurality of divided electrodes 15 may be arranged along the longitudinal direction of the power line or the neutral point lead line 4.

  In this way, the capacitance between the power line or neutral point lead line 4 and the divided electrode 15 can be adjusted, and an optimal high frequency band signal can be detected.

  In the above embodiment, since electric stress is applied to the electrode surface, the electric field concentration portion may be relaxed by covering the electrode surface with an insulating material such as epoxy or performing an edge treatment of the electrode. .

  15 (a) and 15 (b) show a partial discharge detection device for a rotating electrical machine showing a fourth embodiment of the present invention, (a) is an axial sectional view, and (b) is a radial sectional view. The same parts as those in FIG.

  In the fourth embodiment, as shown in FIGS. 15A and 15B, the middle of the metal frame 5 is cut and separated in the radial direction, and a cylindrical electrode 16 having the same diameter as the metal frame is interposed therebetween. Each of the metal frames 5 is arranged concentrically around the power line or the neutral lead-out line 4, and both open ends of the cylindrical electrode 16 are separated by a ring-shaped electrode supporting insulating member 17. In addition to being attached to the open ends, the ends of the connection conductors 18 disposed across the electrodes 16 are connected to the separated metal frames 5 respectively.

  The resistor 13 is connected between the electrode 16 and the metal frame 5, the signal lead wire 2 is connected to the electrode side end of the resistor 13, and the high-frequency current flowing through the resistor 13 is supplied to the detector 3. It is something to be entered.

  Even in such a configuration, partial discharge can be detected by the same action as in the third embodiment, so there is no need to process the inside of the rotating electrical machine, and fixing around the neutral point leader line of the rotating electrical machine. By simply remodeling the child frame, the sensor can be attached to the high voltage portion in a non-contact manner relatively easily and easily.

  In the above embodiment, the high-frequency current flowing through the resistor 13 connected between the electrode 16 and the metal frame 5 (earth) is taken into the detector 3, but as shown in FIGS. 16 (a) and 16 (b). A high-frequency current transformer 14 is inserted into a conductor connected between the electrode 16 and the metal frame 5 (earth), and a high-frequency current detected by the high-frequency current transformer 14 is input to the detector 3. good.

  FIG. 17 is a block diagram showing a partial discharge detection device for a rotating electrical machine showing a fifth embodiment of the present invention. The same parts as those in FIG.

  In FIG. 17, the stator coil 6 of the rotating electrical machine is housed in a slot included in a stator core (not shown) attached to the inner peripheral surface of the stator frame 7.

  In addition, a cylindrical metal frame 5 is attached to the stator frame 7, and a power line or a neutral lead-out line 4 is supported by an insulating support (not shown) on the stator coil 6 on the central axis in the metal frame 5. It is installed.

  Sensors 21 and 22 made of rod-shaped antennas are installed corresponding to the power line or neutral point lead line 4 at a predetermined distance in two places A and B per phase of the power line or neutral point lead line 4. Then, each output is taken into the waveform comparator 23 to compare the waveforms, and the result can be observed by the waveform observation device.

  In the partial discharge detection device having such a configuration, the sensors 21 and 22 and the waveform comparator 23 are connected by the same length of detection lead wires, and the waveforms observed by the simultaneous waveform observation device are shown in FIG. FIG. 19 shows a pulse waveform when a pulse propagated in the direction of entering the rotating electrical machine from the opposite side of the rotating electrical machine is detected. In FIGS. 18 and 19, the horizontal axis represents time, and the vertical axis corresponds to the waveform output (size).

  When a pulse is propagated from the rotating electrical machine side, the output waveform 35 of the sensor 21 is observed in order of the output waveform 36 of the sensor 22 with a delay of several ns as shown in FIG. 18, and the pulse is propagated from the system side. In this case, the output waveform 39 of the sensor 22 and the output waveform 38 of the sensor 21 are observed in this order with a delay of several ns as shown in FIG.

  The delay times 37 and 40 of several ns correspond to the pulse propagation time between the sensors 21 and 22. Therefore, the propagation direction of the pulse can be estimated by detecting the arrival time difference 37 or 40 between the waveforms of the sensors 21 and 22.

  Note that the distance between the sensor 21 and the sensor 22 needs to be such that the waveform time difference between the sensor 21 and the sensor 22 can be identified.

  For example, if the time width of the first half wave that is the first rise of the pulse signal (for example, 35) is about ¼, the arrival time difference can be easily identified by the waveform observer. If the frequency is 10 MHz, the required distance between the sensor installation locations A and B is about 4 m.

  Further, since the vibration period of the pulse waveform becomes longer as the signal frequency is lower, it is necessary to widen the interval between the sensors 21 and 22 in order to accurately detect the arrival time differences 37 and 40 of the pulse waveform.

  In general, a signal including a partial discharge signal propagates from the rotating electrical machine side, whereas noise is mainly from the system side on the opposite side of the rotating electrical machine. By measuring the arrival time difference, noise from the system side can be separated.

  With such a configuration, since the sensor 21 is close to the stator coil 6 that is a partial discharge generation source, an improvement in detection sensitivity of the partial discharge can be expected.

  Even if the lengths of the signal leaders connected to the sensors 21 and 22 are different, if the lengths are known, correction is possible at the time of pulse detection, so that noise from the system side is separated as described above. it can.

  As described above, in the present embodiment, the sensors 21 and 22 are provided at two locations for one phase of the power line or the neutral point lead line 4 inside the metal frame 5 that houses the power line or the neutral point lead line 4 connected to the rotating electrical machine. Since a partial discharge is detected by comparing the arrival time difference between the output signal waveforms from two sensors installed in the same phase at a predetermined distance, there is no need to process the inside of the rotating electrical machine, In addition to remodeling the stator frame around the rotating electrical machine power line or neutral lead-out line, the sensor can be mounted on the high voltage part in a relatively simple and easy manner. Since the pulse from the electric machine side can be separated, the partial discharge can be detected with high accuracy.

  In the above-described embodiment, the case where two sensors 21 and 22 each including a rod-shaped antenna are installed has been described. However, two sensors each including a loop-shaped antenna or a plurality of rod-shaped antennas having one end electrically connected thereto are installed. Needless to say, however.

  In the above embodiment, the sensors 21 and 22 are installed in correspondence with the power line or the neutral lead line 4, but as shown in FIG. 20, one of the two sensors, in this example, the sensor 21 is a stator inside the rotating electrical machine. The end of the coil or the stator coil connecting conductor is installed in a non-contact manner, and the other sensor 22 is placed inside the metal frame 5 that houses the power line or neutral point lead wire 4 connected to the rotating electrical machine. By installing them and taking their outputs into the waveform comparators 23, the same effects as described above can be obtained.

  FIG. 21 is a configuration diagram of a partial discharge detection device for a rotating electric machine showing a sixth embodiment of the present invention. The same parts as those in FIG.

  In FIG. 21, the stator coil 6 of the rotating electrical machine is housed in a slot provided in a stator core (not shown) attached to the inner peripheral surface of the stator frame 7.

  Further, a cylindrical metal frame 5 is attached to the stator frame 7, and a conductor 4 through which a partial discharge pulse signal propagates, such as a phase separation bus, a coil connection conductor, or a neutral point lead line, on the central axis in the metal frame 5. It is arranged to be supported by an insulating support (not shown).

  Two loop antennas 24 and 25 are arranged in the same direction corresponding to the conductor 4 at positions A and B separated by a predetermined distance around the conductor 4, and signals connected to the loop antennas 24 and 25. The lead terminals Aa and Ab or the terminals Ba and Bb are reversed in direction so that the polarities of the first wave peak values of the output waveforms obtained from the signal lead lines of the loop antennas are opposite to each other. Wire as shown.

  Furthermore, when the pulse propagates through the conductor 4 in the direction of entering the rotating electrical machine, the output waveform generated between the terminals Aa and Ab and between the terminals Ba and Bb has the same timing so that the one farther from the rotating electrical machine The length of the signal lead line connected to the loop antenna 25 is increased. That is, the loop antenna 25 is configured such that the signal propagation time of the signal leader of the loop antenna 25 is longer than the signal propagation time of the signal leader of the loop antenna 24 by the signal propagation time between the loop antennas 25 and 24. Increase the length of the signal leader.

  And it connects so that it can take out as a voltage with a polarity mutually opposite to the detection of the same pulse, and each voltage obtained from the common connection point X and Y is taken into the signal processor 26, respectively, and these pulses are taken. The sum of waveforms is detected, and the results can be observed by a waveform observation device.

  FIG. 22 shows an example of output waveforms of the terminals Aa-Ab and Bb-Ba and a sum of these two waveforms when the signal propagates in the direction of entering the rotating electrical machine in the partial discharge detection device having such a configuration.

  In FIG. 22, 41 is a voltage waveform observed at terminals Aa-Ab, 42 is a voltage waveform observed at terminals Ba-Bb, and 43 is a sum waveform of voltage waveforms 41 and 42.

  Conversely, FIG. 23 shows an example of output waveforms of the Aa-Ab and Ba-Bb terminals and a sum of these two waveforms when the signal propagates from the rotating electrical machine side to the outside.

  In FIG. 23, 44 is a voltage waveform observed at terminals Aa-Ab, 45 is a voltage waveform observed at terminals Ba-Bb, and 46 is a sum waveform of voltage waveforms 44 and 45.

  As shown in FIG. 23, the sum of waveforms of the loop antennas 24 and 25 retains the first half wave peak value of the pulse waveform when propagating from the rotating electrical machine side, but propagates from the side entering the rotating electrical machine. In this case, the first half wave peak value is canceled.

  In order to maintain the first half wave of the waveform sum 46 when the pulse propagates from the rotating electric machine shown in FIG. 23 to the outside, the first half of the waveform sum 46 is provided between the loop antennas 24 and 25. A distance corresponding to the time width of the wave is required.

  For example, if the frequency of the pulse signal (for example, 39) is 10 MHz, the necessary distance between the loop antennas 24 and 25 is considered to be about 7 m. In general, since a signal including a partial discharge signal propagates from the rotating electrical machine side and noise is mainly from the system side, the noise from the system side can be separated.

  In the above, the direction of the terminals Aa and Ab of the signal lead lines connected to the two loop-shaped antennas 24 and 25, or the direction of the terminals Ba and Bb are reversed, and the signal lead lines of the respective loop-shaped antennas are used. Although the wiring was made so that the polarities of the first wave peak values of the respective output waveforms obtained were opposite to each other, these loop antennas 24 and 25 were reversed so that opposite voltages were induced. It may be arranged.

  In the above-described embodiment, the loop antennas 24 and 25 are arranged corresponding to the conductors 4 in the metal frame 5. It may be installed around the connection conductor, and the loop antenna 25 may be installed inside the metal frame 5 in which the power line connected to the rotating electrical machine or the neutral lead-out line 4 is accommodated.

  As described above, in this embodiment, the loop antennas 24 and 25 are set apart from each other by a predetermined distance inside the metal frame 5 in which the power line or the neutral lead line 4 connected to the rotating electrical machine is housed, and connected to each antenna. The signal lead wire from the antenna is wired so that the polarities of the peak values of the output pulse waveform obtained from the signal lead wire are opposite to each other, and connected to the antenna farther from the stator coil of the rotating electrical machine A pulse signal that induces both antennas so that the pulse output to the signal lead wire terminal reaches the same time as the pulse output to the signal lead wire terminal connected to the antenna closer to the stator coil of the rotating electrical machine Is detected in the signal processor 26 and the sum of the pulse waveforms is detected, so there is no need to machine the rotating electrical machine, and the neutral frame or the stator frame around the power line is modified. Only that, in addition to being able to mount the sensor in a non-contact high voltage portions relatively simple and easily possible to increase the detection sensitivity.

  In the above embodiment, two loop antennas 24 and 25 are installed. However, the same effect as described above can also be obtained when two loop antennas connected in series are installed.

  24 (a) and 24 (b) show the structure of a microstrip antenna as a sensor used in the partial discharge detection device for a rotating electric machine according to the seventh embodiment of the present invention, (a) is a longitudinal sectional view, (B) is sectional drawing of the width direction.

  24A and 24B, reference numeral 61 denotes a coaxial cable having a characteristic impedance of 50Ω. The coaxial cable 61 includes a flat plate portion and a 50Ω termination resistor 62. The flat plate portion is formed on the flat plate electrode 63 with an insulator 64, The transmission line 65 has a three-layer structure, and an upper portion thereof is covered with an insulating layer 66.

  The characteristic impedance between the transmission line 65 and the plate electrode 63 determined from these geometrical arrangements is 50Ω, which is the same as that of the termination resistor 61.

  The signal lead line uses a coaxial cable having a characteristic impedance of 50Ω, and connects the flat transmission line 65 and the center line of the coaxial cable 60 and the flat plate electrode 63 and the coaxial cable shield line.

  Note that the coaxial cable used as the signal lead-out line prevents noise from being mixed from the surrounding area other than the antenna.

  FIG. 25 is an equivalent circuit of the microstrip antenna shown in FIG.

  In FIG. 25, 67 is the characteristic impedance of the coaxial cable, 68 is the electric field component of the electromagnetic wave, 69 is the magnetic field component of the electromagnetic wave, and the angle between the traveling direction 70 of the electromagnetic wave propagating in space and the transmission line 65 is θ.

FIG. 26 shows the directivity of the currents I ₀ and I _l generated in the microstrip antenna by the electromagnetic wave propagating in the space.

The end current I ₀ of the microstrip generated in the coaxial cable 61 has the highest sensitivity when the angle formed with the transmission line 65 of the antenna with respect to the electromagnetic wave traveling direction is 0 °. In other words, the output of the coaxial cable is the largest with respect to the electromagnetic wave propagating from the direction of the coaxial cable 61.

  Electromagnetic waves propagate in the space inside the stator frame of the rotating electrical machine or on the inner surface of the metal frame that houses the power line or neutral lead wire connected to the stator coil of the rotating electrical machine due to the occurrence of partial discharge in the stator coil.

  Therefore, the microstrip antenna 60 having the above-described structure is installed on the inner surface of the stator frame 7 as shown in FIG. 27 or the inner surface of the metal frame 5 as shown in FIG. 28 in accordance with the direction of the stator coil. This makes it possible to detect a partial discharge signal with high sensitivity.

  FIG. 29 shows a waveform diagram in which the microstrip antenna 60 described above is installed between the high voltage conductor and the metal frame to detect the partial discharge of the stator coil.

  As apparent from the waveform shown in FIG. 29, the pulse waveform 72 is generated in the coaxial cable connected to the antenna by the partial discharge pulse signal 71, which indicates that the partial discharge signal can be detected.

  Further, if there is a portion where electromagnetic waves leak to the outside in the frame 7 or the metal frame 5 of the rotating electrical machine, it is considered that partial discharge can be detected by installing a microstrip line on the outer surface of the surrounding frame.

  As described above, in this embodiment, one end is connected to the terminating resistor 62 on the inner surface or outer surface of the metal frame containing the power line or neutral point lead wire connected to the fixed frame inner surface or outer surface of the rotating electric machine or the stator coil of the rotating electric machine. By installing the microstrip antenna 60 composed of the flat plate electrode 63, the insulator 64, and the transmission line 65 so that partial discharge can be detected, there is no need to process the inside of the rotating electric machine, and the power line or neutral point of the rotating electric machine By simply remodeling the stator frame around the leader line, the sensor can be attached to the high voltage portion relatively easily and easily without contact.

  In the above embodiment, when a plurality of microstrip antennas 60 are installed inside the stator frame of the rotating electrical machine using the directivity of the antenna, and partial discharge occurs due to deterioration of the stator coil, the stator coil to the stator. The partial discharge generation source may be specified by comparing the signal intensity output from each antenna by the electromagnetic wave propagating in the space between the frames.

The block diagram of the partial discharge detection apparatus of the rotary electric machine which shows the 1st Embodiment of this invention. The figure which shows a rod-shaped antenna and its support structure as a sensor in the embodiment. The block diagram which shows the structural example of the detector in the same embodiment. The output voltage waveform figure for demonstrating the effect | action of the detector. The waveform diagram which displayed the example of the waveform detected with the partial discharge pulse and rod-shaped antenna which are propagated to a conductor in the embodiment with the waveform observer. The figure which shows a loop-shaped antenna and its support structure as a sensor in the embodiment. (A) is an axial sectional view of a partial discharge detection device for a rotating electrical machine showing a second embodiment of the present invention, and (b) is a radial sectional view. The graph which shows the relationship between the number of rod antennas, and an antenna output voltage in the same embodiment. The figure which shows the example which has arranged the several rod-shaped antenna by which the one side was connected in series as a sensor in the same embodiment in linear form or circular arc shape. (A) is axial sectional drawing of the partial discharge detection apparatus of the rotary electric machine which shows the 3rd Embodiment of this invention, (b) is radial direction sectional drawing. (A) is an axial sectional view showing a connection configuration for taking a high-frequency current into a detector from a resistor connected between an electrode and a metal frame in the same embodiment, and (b) is a radial sectional view. The waveform diagram which displayed the example of the waveform detected via the partial discharge pulse propagated to a conductor and the resistor connected to the electrode in the same embodiment. (A) is the axial direction sectional view which shows the connection structure for taking in a high frequency current into a detector from the current transformer inserted in the conductor which connects between an electrode and a metal frame in the embodiment, (b). Is a radial cross-sectional view. (A) is an axial sectional view showing a configuration in which arc-shaped divided electrodes are arranged concentrically around a power line in the embodiment, and (b) is a radial sectional view. (A) is an axial sectional view of a partial discharge detector for a rotating electrical machine showing a fourth embodiment of the present invention, and (b) is a radial sectional view. (A) is the axial sectional view which shows the connection structure for taking in a high frequency current into a detector from the high frequency current transformer inserted in the conductor which connects between an electrode and a metal frame in the embodiment, (b) ) Is a radial cross-sectional view. The block diagram which shows the partial discharge detection apparatus of the rotary electric machine which shows the 5th Embodiment of this invention. FIG. 3 is a pulse waveform diagram in which detection conductors having the same length are connected to two sensors in the same embodiment, and respective outputs are observed with a simultaneous waveform observation device. The pulse waveform figure which observed each output with the simultaneous waveform observation apparatus when the pulse which propagated in the direction which approached a rotary electric machine from the opposite side of a rotary electric machine was detected similarly. In the same embodiment, the block diagram which installed the end part of the stator coil in a rotary electric machine in one of two sensors, and installed the other in the metal frame. The block diagram of the partial discharge detection apparatus of the rotary electric machine which shows the 6th Embodiment of this invention. In the same embodiment, the wave form diagram when a signal propagates in the direction which approachs a rotary electric machine. Similarly, the waveform diagram when the signal propagates from the rotating electrical machine side to the outside. (A), (b) shows the structure of a microstrip antenna as a sensor in the 7th embodiment of the present invention, (a) is a longitudinal section, and (b) is a width section. The equivalent circuit diagram of the microstrip antenna. In the embodiment, shows the directivity of the current I ₀ and I _l occurring microstrip antenna by the electromagnetic wave propagating in space. The figure which shows the state which attached the microstrip antenna in the same embodiment to the inner surface of a stator frame. The figure which shows the state which attached the microstrip antenna in the same embodiment to the inner surface of a metal frame. The wave form diagram which detected the partial discharge of the stator coil with the microstrip antenna installed between the high voltage conductor and the metal frame in the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rod-shaped antenna, 2 ... Signal leader line, 3 ... Detector, 4 ... Neutral point leader line or electric power line, 5 ... Metal frame, 6 ... Stator coil, 7 ... Stator frame, 8 ... Insulation for antenna support Member: 9 ... Loop antenna, 10 ... Connection conductor, 11 ... Cylindrical electrode, 12 ... Electrode supporting insulating member, 13 ... Resistor, 14 ... High frequency current transformer, 15 ... Arc-shaped divided electrode, 16 ... Cylindrical electrode, 17 ... insulating member for electrode support, 18 ... connecting conductor, 21,22 ... sensor consisting of rod-shaped antenna (or loop-shaped antenna), 23 ... waveform comparator, 24,25 ... loop-shaped antenna, 26 ... Signal processor, 60 ... Microstrip antenna, 61 ... Coaxial cable 62 ... Terminal resistor, 63 ... Plate electrode, 64 ... Insulator, 65 ... Transmission line, 66 ... Insulating layer

Claims (13)

  A metal frame connected to a stator frame of a rotating electrical machine, a power line or a neutral point lead line which is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil, and the metal frame A sensor comprising a rod-like antenna or a loop-like antenna, which is installed around the power line or neutral point lead line of which a partial discharge signal propagated to the power line or neutral point lead line is electrostatically and electromagnetically induced, and A partial discharge detection device for a rotating electrical machine, comprising: a detector that takes in a signal generated in a sensor through a signal lead line and detects partial discharge by signal processing.   A metal frame connected to a stator frame of a rotating electrical machine, a power line or a neutral point lead line which is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil, and the metal frame A plurality of rod-shaped antennas that are arranged around the power line or neutral point lead line and are electrically connected at one end to which a partial discharge signal propagated to the power line or neutral point lead line is electrostatically and electromagnetically induced And a detector for detecting a partial discharge by signal processing by taking in a signal generated by the sensor through a signal lead line.   One end where the partial discharge signal generated by the deterioration of the stator coil is electrostatically and electromagnetically induced is electrically connected to the end of the stator coil inside the stator frame of the rotating electric machine or around the coil connection conductor. A partial discharge detection of a rotating electrical machine comprising: a sensor comprising a plurality of rod-shaped antennas; and a detector for detecting a partial discharge by signal processing by taking a signal generated by the sensor through a signal lead line apparatus.   A metal frame connected to a stator frame of a rotating electrical machine, a power line or a neutral point lead line which is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil, and the metal frame A sensor comprising a plurality of loop antennas that are arranged in series around the power line or neutral point lead line and in which the partial discharge signal propagated to the power line or neutral point lead line is electrostatically and electromagnetically induced And a detector for detecting a partial discharge by signal processing by taking a signal generated in the sensor through a signal lead line, and a partial discharge detection device for a rotating electrical machine.   A metal frame connected to a stator frame of a rotating electrical machine, a power line or a neutral point lead line which is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil, and the metal frame A cylindrical or arc-shaped electrode that is concentrically arranged on the power line or neutral point lead line and has electrostatic coupling with the power line or neutral point lead line and connected between this electrode and the metal frame or between the electrode and the ground And a detector for detecting a partial discharge by signal processing by taking in a high-frequency current flowing through the resistor from the electrode when a partial discharge signal is propagated to the power line or the neutral point lead line. A partial discharge detecting device for a rotating electrical machine, characterized in that:   A metal frame connected to a stator frame of a rotating electrical machine, a power line or a neutral point lead line which is disposed in the metal frame and propagates a partial discharge signal generated by deterioration of the stator coil, and the metal frame A cylindrical or arc-shaped electrode that is concentrically arranged on the power line or neutral point lead line and has electrostatic coupling with the power line or neutral point lead line and connected between this electrode and the metal frame or between the electrode and the ground A high-frequency current transformer provided in the connection line and a signal processing by taking in a high-frequency current flowing through the connection line when the partial discharge signal is propagated to the power line or the neutral lead-out line from the high-frequency current transformer A partial discharge detection device for a rotating electric machine, comprising:   A rotating electrical machine comprising the partial discharge detection device according to any one of claims 1 to 6.   In the metal frame connected to the stator frame of the rotating electrical machine, a power line or a neutral lead line that propagates a partial discharge signal generated by the deterioration of the stator coil is disposed, and a rod-shaped antenna, a loop-shaped antenna, one end Are installed at a distance of at least two points per phase of the power line or the neutral lead line, and are arranged in the same phase. Detect the partial discharge signal generated by the deterioration of the stator coil by comparing the arrival time difference of the output signal waveform obtained through two signal leaders with the same or known difference connected to each of the two sensors A partial discharge detection method for a rotating electrical machine.   In the metal frame connected to the stator frame of the rotating electrical machine, a power line or a neutral lead line that propagates a partial discharge signal generated by the deterioration of the stator coil is disposed, and a rod-shaped antenna, a loop-shaped antenna, one end One of two sensors consisting of any one of a plurality of rod-shaped antennas electrically connected to each other is installed at the end of the stator coil inside the stator frame or around the stator coil connecting conductor, and the other is Installed around the power line or neutral point lead line in the metal frame with a predetermined distance from the one sensor, and the lengths connected to the two sensors are the same or have a known difference. A partial electric discharge signal generated by deterioration of the stator coil is detected by comparing a difference in arrival time of output signal waveforms obtained through two signal lead lines. Minute discharge detection method.   In the metal frame connected to the stator frame of the rotating electrical machine, a power line or a neutral lead line for propagating a partial discharge signal generated by deterioration of the stator coil is disposed, and the power line or the middle in the metal frame is disposed. Two sensors consisting of a loop antenna or a plurality of loop antennas connected in series around the sex lead line are placed at a predetermined distance, and the output pulse of the signal lead line connected to each sensor Electrical pulses that are arranged so that the polarities of the peak values of the waveforms are opposite to each other or that are wired for signal leaders from each sensor and propagate through the power line or neutral point leader in the direction of entering the rotating electrical machine The pulse signal output to the signal lead wire terminal connected to the sensor separated from the stator coil side induced by the signal flows through the power line or the neutral lead wire. The length of the signal lead line of each sensor is adjusted so as to reach the same time as the pulse signal output to the signal lead line terminal connected to the sensor on the stator coil side induced by A partial discharge detection method for a rotating electric machine, comprising: detecting a partial discharge signal generated by deterioration of the stator coil from a sum of pulse waveforms obtained through a signal lead line.   In the metal frame connected to the stator frame of the rotating electrical machine, a power line or a neutral lead line that propagates a partial discharge signal generated by the deterioration of the stator coil is disposed, and connected to a loop antenna or in series. One of the two sensors composed of a plurality of loop antennas is installed at the end of the stator coil inside the stator frame or around the stator coil connecting conductor, and the other is set at a predetermined distance from the one sensor. And placed around the power line or neutral point leader in the metal frame, and arranged so that the polarities of the peak values of the output pulse waveform of the signal leader connected to each sensor are opposite to each other. Alternatively, the signal lead lines from each sensor are wired, and the stator core induced by the electric pulse signal propagating through the power line or neutral point lead line in the direction of entering the rotating electrical machine. A signal connected to the sensor on the stator coil side, in which a pulse signal output to a signal lead terminal connected to a sensor remote from the coil side is induced by the same pulse signal flowing through the power line or neutral lead line The length of the signal lead line of each sensor is adjusted so as to reach the same time as the pulse signal output to the lead line terminal, and the sum of the pulse waveforms obtained through these two signal lead lines is used to A partial discharge detection method for a rotating electrical machine, characterized in that a partial discharge signal generated by deterioration is detected.   A conductor whose inner side or outer surface is connected to the inner or outer surface of a stator frame of a rotating electric machine or a metal frame that is connected to the stator frame of a rotating electric machine and has a power line or a neutral point lead line inside, and is connected to a terminating resistor on one side A microstrip antenna composed of a flat plate, an insulating plate, and a transmission line is installed, and the metal from the stator coil to the stator frame or from the power line or neutral point lead wire by partial discharge generated by deterioration of the stator coil A partial discharge detection method for a rotating electrical machine, wherein a partial discharge of the stator coil is detected by processing a current signal output from the microstrip antenna by an electromagnetic wave propagating in a space between frames.   When a plurality of microstrip antennas composed of a conductor plate, insulation plate, and transmission line, one side of which is connected to a termination resistor, are installed inside the stator frame of a rotating electrical machine, and partial discharge occurs due to deterioration of the stator coil A part of a rotating electrical machine characterized by identifying a partial discharge generation source by comparing the signal intensity output from each microstrip antenna by electromagnetic waves propagating in a space between the stator frames from a stator coil Discharge detection method.

Images