JP2884805B2 - Abnormality detection device for rotating electric machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electrical machine abnormality detecting apparatus capable of detecting and constantly monitoring an abnormality caused by insulation deterioration of a stator winding.

[0002]

2. Description of the Related Art In recent years, the scale of plants in general industry has been steadily increasing in size, and as a result, the size of rotating electric machines has increased and the number of installations has also increased.

Therefore, since high reliability is particularly required for such a rotating electric machine, it is necessary to reliably perform maintenance and inspection and to prevent sudden accidents such as insulation breakdown.

Conventionally, as a method of judging insulation deterioration of a rotating electric machine, for example, for a stator, after stopping the operation of the rotating electric machine, a high voltage is applied to a winding to obtain various electrical characteristics (insulation resistance, AC current). , Dielectric loss angle, partial discharge, etc.), and an electrical method is used to estimate the degree of deterioration of the insulator at each location. For the rotor, the rotating electric machine is disassembled and the rotor is taken out In addition, a mechanical method of judging the mechanical damage state of the insulating portion and the deterioration state of the winding fixing force by visual inspection and tapping sound is used.

However, in order to judge deterioration by these methods, it is necessary not only to stop the operation of the rotating electric machine but also to disconnect the line connection and, in some cases, to remove the rotor. For this reason, performing a deterioration judgment by such a series of methods requires a great deal of time, labor and cost, and has a drawback that frequent deterioration judgment tests are difficult to perform. In addition, since the preparation may take time to carry out such a method, there is a disadvantage that when the deterioration progresses rapidly, it is not possible to sufficiently cope with the deterioration.

Therefore, in order to eliminate such inconvenience, there has been proposed a partial discharge detecting device for electric equipment in which a metal conductor is arranged as an antenna for detecting partial discharge in the vicinity of an insulated winding of electric equipment.

FIG. 15 is an explanatory perspective view showing a conventional partial discharge detecting device for electric equipment disclosed in Japanese Utility Model Laid-Open Publication No. 55-51775, and FIG. 16 is a block diagram showing the same. In FIG. 15, 1 is a stator, 2 is a stator core, 3 is a stator winding end, and 4 is an antenna wire for detecting partial discharge. Electromagnetic waves generated by the partial discharge pulse current are captured by the antenna wire 4, and the output from the antenna wire 4 is led to the detection circuit 6 via the lead wire 5 as shown in FIG. A normal voltage frequency component is removed through a high-pass filter 7 and further supplied to a partial discharge counter 8 for partial discharge measurement.

However, subsequent research results have revealed that high-frequency currents based on partial discharges propagating in the stator windings are significantly attenuated in the windings. For example, FIG.
7 is a magazine: IEEE PROCEEDINGS, VOL.
132, Pt. B, No. 5, SEPTEMBER, 1
9B is a characteristic diagram of a signal level propagating in a winding for each frequency band shown in 985. FIG. Characteristic curve A is 20-100
kHz, b is 20-300 kHz, c is 20-1000
kHz and D are the characteristics in the frequency band of 20-3000 kHz. As is clear from the figure, the signal attenuation in the winding is remarkable, and particularly in a high frequency band effective for electromagnetic wave detection, the signal level is reduced to 1/2 to 1 while propagating in the winding for one to two turns.
It can be seen that the sensitivity is attenuated to / 10 and the detection sensitivity is lowered.

[0009]

A conventional partial discharge detecting device for detecting a partial discharge of an electric device is constructed as described above, and a high frequency current based on the partial discharge propagating in a stator winding is applied to a stator. The attenuation in the winding is remarkable, and the detection sensitivity of the signal of the partial discharge generated at a position more than one turn away from the slot where the antenna is provided is very poor in the detection with the antenna provided in the slot. was there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an abnormality detection device for a rotating electric machine which can constantly monitor an abnormality of a stator winding with high detection sensitivity.

[0011]

SUMMARY OF THE INVENTION An abnormality detecting apparatus for a rotating electric machine according to the present invention detects an electromagnetic wave radiated based on a partial discharge generated due to an abnormality in a stator winding with an antenna to detect the abnormality in the stator winding. The antenna is disposed on the inner wall surface of the stator frame accommodating the stator at a position facing the stator winding end protruding outside the stator core slot.

Further, the loop antenna is arranged such that a pair of loop surfaces is parallel and orthogonal to the winding axis of the stator winding end, respectively.

Further, a plurality of antennas are arranged on the inner peripheral wall surface of the stator frame.

According to another aspect of the present invention, there is provided an abnormality detecting device for a rotating electric machine, wherein the stator winding propagates inside a coil support ring which supports a stator winding end protruding outside a stator core slot. The antenna is embedded at a position where the antenna interlinks with a magnetic field generated by a high-frequency current.

[0015]

In the rotating electric machine abnormality detecting device according to the present invention, the antenna is arranged at a position facing the stator winding end on the inner wall surface of the stator frame, so that a sufficient insulation distance from the high-voltage stator winding is provided. Can be provided, and the high-frequency wave can be detected at a location where the attenuation is small without lowering the reliability of the rotating electric machine, so that the detection sensitivity is improved.

Further, since the loop antennas are arranged so that the loop surfaces forming a pair are parallel and perpendicular to the winding axis, there is no incident blind spot of electromagnetic waves, and the detection sensitivity is improved.

Further, by providing a plurality of antennas, an abnormal part can be specified.

Further, since the antenna is provided inside the coil support ring so as to interlink with the magnetic field generated by the high-frequency current propagating through the stator winding, the high-frequency wave can be detected at a place where the attenuation is small. And the detection sensitivity is improved.

[0019]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings. FIG.
1 is a cross-sectional configuration diagram illustrating an abnormality detection device for a rotating electric machine according to a first embodiment of the present invention. Reference numeral 10 denotes a rotating electric machine, in this case, a generator, and a stator frame 11, a stator core 2, a stator winding 1
2 and a rotor 13. The stator winding 12 is accommodated and wound in a slot groove provided in the stator core 2, and a portion of the stator winding 2 which is outside the stator core 2 for winding is formed by a stator winding end 3. Called.

Opposed to the stator winding end 3, three pairs, ie, six loop antennas 14, 15, 16, 17 (the other two are not shown) are arranged on the inner wall surface of the stator frame 11. I have. Paired loop antennas 14 and 15 and 1
Reference numerals 6 and 17 are arranged such that the loop plane is perpendicular to the winding axis of the stator winding end 3 horizontally and vertically.
In addition, the arrangement position is a position facing the winding closest to the line side of the stator winding end 3.

FIG. 2 is an explanatory view showing an installation position of the loop antenna in correspondence with a three-phase winding diagram of a general rotating electric machine. As shown in FIG. 2, the loop antenna 14 (on the inner wall of the stator frame 11 facing the position 23 of the stator winding end 3 closest to the line side of the U-phase 20 so that the loop surface is orthogonal to the winding axis. (Not shown), the loop antenna 15 is arranged so that the loop surface is horizontal to the winding axis. Similarly, the stator winding end 3 closest to the line side of the V-phase 21
Loop antennas 16 (not shown) and 17 also face the position 24 of the stator winding end 3 closest to the line side of the W-phase 22, and the loop antenna 18 (not shown) (Not shown) and 19 are arranged. Each of the loop antennas 14 to 19 has a bushing 28a which penetrates through a central portion of metal lids 27a and 27b for closing openings of small cases 26a and 26b attached to the stator frame 11.
Attached via 28b

FIG. 3 (a) shows loop antennas 14 and 15.
As shown in the equivalent circuit diagram of FIG. 4B, detection impedances 29 and 30 are respectively connected, and a measurement cable for transmitting detection signals S ₁ and S ₂ at both ends of the detection impedances 29 and 30 is shown in the block diagram of FIG. It is connected to an abnormality detector 38. The loop antennas 16 to 19 have the same configuration. The abnormality detector 38 includes a signal amplification circuit 33, a filter circuit 34, a discharge detection operation circuit 35, an abnormality determination circuit 36, and a display circuit 37.

Next, the operation of this embodiment will be described. During operation of the generator 10, a high voltage is generated in the stator winding 12. If an abnormality occurs in the stator winding 12 during operation, a partial discharge occurs in the stator winding 12, and a high-frequency current due to the partial discharge propagates through the stator winding 12, thereby causing several hundred kHz to several tens MHz. Electromagnetic waves are emitted. This radiated electromagnetic wave is detected by loop antennas 14 to 19 provided parallel and perpendicular to the winding axis of the stator winding end 3.

Since the voltage generated in the stator winding 12 is the highest on the line side, an abnormality of the stator winding 12 due to an electrical factor is more likely to occur on the line side.
Also, the probability of occurrence of partial discharge in the line having a higher voltage is higher. Thus, the electromagnetic waves based on the partial discharge are detected with high sensitivity by the loop antennas 14 to 19 provided at the position facing the stator winding end 3 closest to the line side.

Further, since the high-frequency current propagating through the stator winding 12 has a characteristic of being significantly attenuated in the winding, the high-frequency current is provided at a position facing the most line side of the stator winding end 3. Therefore, a radiated electromagnetic wave due to the high-frequency current can be detected at a location where the high-frequency current based on the partial discharge hardly attenuates.

The detection signals S _{1 to} S ₆ detected by the loop antennas 14 to 19 are input to the amplification circuit 33,
Is input to the discharge detection arithmetic circuit 35 through the filter circuit 34. The discharge detection calculation circuit 35 detects and calculates the discharge amount, and specifies the discharge generation phase. The output of the discharge detection calculation circuit is input to the abnormality determination circuit 36, and is compared with data registered in advance. An abnormality is determined based on a discharge amount and a generation pattern of a certain level or more, and the result is displayed on a display circuit 37.

In this embodiment, a plurality of pairs of loop antennas having loop surfaces orthogonal to each other are arranged so as to face the stator winding end 3 on the most line side. It is possible to detect a portion where the high-frequency current based on the discharge is hardly attenuated, to detect the electromagnetic wave based on the partial discharge radiated from the stator winding end 3 with high sensitivity, and to specify a portion where the partial discharge is occurring. In addition, since the loop antenna is mounted on the stator frame 11 and a sufficient insulation distance can be provided from the high-voltage stator winding 12, it is always monitored during operation without lowering the reliability of the rotating electric machine. And abnormality detection.

Embodiment 2 In Embodiment 1 described above, the loop antennas 14 to 19 are provided at positions facing the joint 3 of the stator winding end so that the loop plane is perpendicular to the winding axis horizontally and vertically. As shown in the explanatory diagram of FIG.
The same effect can be obtained even if the loop surfaces are arranged in parallel along the winding of the stator winding end 3.

Embodiment 3 In Embodiment 1, the two loop antennas 14 and 15 are paired so that the loop surface of the loop antenna is perpendicular to the winding axis of the stator winding end 3 horizontally and vertically. However, as shown in the perspective view of FIG. 6, two loop surfaces 10 orthogonal to each other are formed on one antenna.
The same effect can be obtained by disposing the loop antenna 114 having a configuration having 1, 102. As shown in the configuration diagram of FIG. 7, the loop antenna 114 covers the periphery of the coils 104a and 104b with electrostatic shields 103a and 103b, and the coils 104a and 104b are located at the center of the electrostatic shields 103a and 103b. Are supported by an insulating support 105. A gap is provided in a part of the electrostatic shields 103a and 103b to prevent generation of an eddy current. Coil 104
a and the coil 104b are connected in parallel, and the lead portion is provided with a detection impedance 127. The leads of the coils 104a, 104b are
It is guided outside the electrostatic shields 103a and 103b through the insulating terminals 105a and 105b provided on the 103b.

Fourth Embodiment FIG. 8 is a sectional view of a main part of a fourth embodiment of the present invention, showing a partial cross section of a generator stator 1, and FIG. 9 is a plan development explanatory view taken along line AA 'of FIG. FIG. 10 is a perspective view showing a coil supporting ring and a loop antenna according to the fourth embodiment.
The stator windings 12a and 12b are accommodated in slot grooves provided in the stator core 2. This stator winding 12a,
In order to reduce electromagnetic vibrations during operation, a coil support 44 fixed to the stator frame 11 together with the end finger 43, a coil support insulation 45, and coil support rings 46 and 47 made of an insulator are provided on the 12b. ing.

The surfaces of the stator windings 12a and 12b are coated with a low-resistance paint within a predetermined distance L from the end of the stator core 2 and have the same ground potential as the stator core 2. A loop antenna 48 for electromagnetic wave detection is provided inside the coil support ring 46 provided within the range of the fixed distance L. The lead wire 49 of the loop antenna 48 is guided to the abnormality detector 38 via a hermetic terminal 52 penetrating a central portion of a metal cover 51 that closes an opening of a small case 50 attached to the stator frame 11.

The coil support ring 46 is an insulator made of glass fiber and epoxy resin, and the loop antenna 48 is embedded in the insulator at the same time as the coil support ring 46 is manufactured as shown in FIG. A lead wire 49 is formed and led out of the coil support ring 46. Impedance 24a is provided between the lead wire 49, it has a configuration to obtain a detection signal V _1.

Next, the operation of the fourth embodiment configured as described above will be described. If an abnormality occurs in the stator winding 12 during the operation of the generator, electromagnetic waves are radiated due to the partial discharge that occurs. A loop antenna 48 is provided at a position that interlinks with the radiated electromagnetic wave, and an abnormality of the stator winding 12 is known by detecting the radiated electromagnetic wave. Since a fixed distance L from the end of the stator core 2 at the stator winding end 3 has the same ground potential as that of the stator core 2, the loop antenna 48 can be safely installed, and signal detection can be performed. Easy to do.

The detected signal V ₁ is guided to an abnormality detector 38 shown in the block diagram of FIG. Signal V ₁ which is sent to the abnormality detector 38 is input to the amplifier circuit 33 as in the above embodiment, the output is filtered by a filter circuit 34 of the amplifier circuit 33, is detected, is input to the discharge detection calculation circuit 35, the discharge The amount is detected and calculated. The output is input to an abnormality determination circuit 36, which compares the output with data registered in advance, determines an abnormality, and displays the result on a display circuit 37.

In this embodiment, an antenna 48 for detecting an electromagnetic wave radiated from the stator winding 12 is provided with a coil support ring 46.
Embedded in the position interlinking with the radiated electromagnetic wave inside, the abnormality of the stator winding 12 can be detected with high sensitivity in a place where the high-frequency wave is hardly attenuated, without lowering the reliability of the rotating electric machine. Also, during operation, constant monitoring and abnormality detection can be performed.

Fifth Embodiment In the fourth embodiment, the loop antenna 48 is used for detecting the radiated electromagnetic wave based on the partial discharge. However, a similar effect can be obtained by providing a ferrite bar antenna. In this embodiment, a case where a ferrite bar antenna is used will be described.
FIG. 12 is a perspective view showing a coil support ring and a ferrite bar antenna according to the fifth embodiment, and FIG. 13 is a block diagram showing an abnormality detector 38 according to the fifth embodiment. FIG.
As shown in FIG. 7, three ferrite bar antennas 60, 61, and 62 having good directivity characteristics in which a coil is wound around a part of a ferrite round bar in a coil support ring 46 have directivities from the stator winding end 3. It is arranged and embedded so as to be in the same direction as the radiated electromagnetic wave. The positions in the circumferential direction are U-phase, V-phase, and W-phase, which are closest to the line side of the stator winding 12.
This is a position facing a phase (not shown). A detection impedance 54b, 54c, 54d is provided between the lead wires of the ferrite bar antennas 60, 61, 62,
The detection signals V ₂ , V ₃ , and V ₄ are obtained.

Next, the effect of the fifth embodiment configured as described above will be described. As described above, since the voltage generated on the stator winding 12 during the operation of the generator is highest on the line side, the abnormality of the stator winding 12 due to electrical factors is more likely to occur on the line side, The probability of occurrence of partial discharge in the secondary winding 12 is higher on the line side where the voltage is higher.
Therefore, the U-phase, V-phase,
Three ferrite bar antennas 60, 6 facing W phase
1,62 are provided and the detection sensitivity is high.
Signals V ₂ , V ₃ , and V ₄ for each of the V and W phases can be obtained. The detection signals V ₂ , V ₃ , and V ₄ are detected and calculated by a discharge detection calculation circuit 35 provided in the abnormality detector 38 shown in FIG. Is displayed with.

In Embodiments 4 and 5, the coil supporting ring is provided with a loop antenna or a ferrite bar antenna. However, the same applies to the case where the dipole antenna 63 is provided as shown in the perspective view of FIG. Has the effect of

In the above embodiment, the case of a generator has been described, but it goes without saying that the same effect can be obtained with a rotating electric machine such as a water turbine generator or an induction motor.

[0040]

As described above, the abnormality detection device for a rotating electric machine according to the present invention is provided on the inner wall surface of the stator frame accommodating the stator, at the stator winding end protruding outside the stator core slot. Since an antenna for detecting an electromagnetic wave radiated by the high-frequency current based on the partial discharge generated due to the abnormality of the stator winding propagating through the stator winding is arranged at the opposed position, There is an effect that the abnormalities of the winding can be monitored by detecting the electromagnetic wave with high sensitivity at a place where the attenuation is small. Further, since a sufficient insulation distance can be provided from the high-voltage stator winding, the reliability of the rotating electric machine is not reduced.

In addition, since the loop antenna is disposed so that each of the pair of loop surfaces is parallel and orthogonal to the winding axis of the end of the stator winding, there is no blind spot of electromagnetic waves, and the detection sensitivity is improved. .

Further, since a plurality of antennas are provided on the inner peripheral wall surface of the stator frame, an abnormal portion can be specified.

According to another aspect of the present invention, a high-frequency current propagating through the stator winding is provided inside a coil support ring that supports a stator winding end protruding outside a stator core slot. Since the antenna is buried in a position interlinking with the generated magnetic field, the high-frequency wave can be detected at a place where the attenuation is small, and the detection sensitivity is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram illustrating an abnormality detection device for a rotating electric machine according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a loop antenna installation position according to the first embodiment of the present invention.

FIG. 3 is an equivalent circuit diagram according to the first embodiment of the present invention.

FIG. 4 is a block diagram of an abnormality detector according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a loop antenna installation position according to a second embodiment of the present invention.

FIG. 6 is a perspective view illustrating a loop antenna according to a third embodiment of the present invention.

FIG. 7 is a configuration diagram illustrating a loop antenna according to a third embodiment of the present invention.

FIG. 8 is a cross-sectional configuration diagram illustrating a main part of an abnormality detection device for a rotating electric machine according to a fourth embodiment of the present invention.

9 is a plane development explanatory view taken along line AA ′ of FIG. 8;

FIG. 10 is an explanatory perspective view according to a fourth embodiment of the present invention.

FIG. 11 is a block diagram of an abnormality detector according to a fourth embodiment of the present invention.

FIG. 12 is an explanatory perspective view according to a fifth embodiment of the present invention.

FIG. 13 is a block diagram of an abnormality detector according to a fifth embodiment of the present invention.

FIG. 14 is a perspective explanatory view according to still another embodiment of the present invention.

FIG. 15 is an explanatory perspective view showing a conventional partial discharge detection device for electric equipment.

FIG. 16 is a block diagram of a conventional partial discharge detection device for electric equipment.

FIG. 17 is a characteristic diagram of a signal level propagating in a winding for each frequency band.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator 3 Stator winding end part 10 Generator 11 Stator frame 12 Stator winding 14-19 Loop antenna 38 Abnormality detector 46 Coil support ring 60-62 Ferrite bar antenna

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-162930 (JP, A) JP-A-59-2518 (JP, A) JP-A-61-167880 (JP, A) JP-A 63-162880 247674 (JP, A) JP-A-60-210774 (JP, A) JP-A-2-27274 (JP, A) JP-A-3-221880 (JP, A) JP-A-2-297077 (JP, A) Japanese Utility Model Showa 55-51775 (JP, U) Japanese Utility Model Hei 2-63478 (JP, U) Japanese Utility Model Showa 61-98340 (JP, U) Japanese Patent Publication No. 5-58512 (JP, B2) Japanese Patent Publication No. Hei 6-27764 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) G01R 31/12 G01R 31/02 G01R 31/34

Claims (4)

(57) [Claims] An abnormality detecting device for a rotating electric machine, wherein an electromagnetic wave based on a partial discharge generated due to an abnormality in a stator winding is detected by an antenna to detect an abnormality in the stator winding, wherein the stator is housed. An abnormality detection device for a rotating electric machine, wherein a loop antenna is disposed on an inner wall surface of a stator frame at a position facing the stator winding end protruding outside of a stator core slot. 2. The rotation according to claim 1, wherein the antennas are arranged such that loop surfaces forming a pair in the loop antenna are parallel and orthogonal to a winding axis of a stator winding end, respectively. Electric machine abnormality detection device. 3. The abnormality detection device for a rotating electric machine according to claim 1, wherein a plurality of antennas are provided on an inner peripheral wall surface of the stator frame. 4. An abnormality detecting device for a rotating electric machine, wherein an electromagnetic wave based on a partial discharge generated due to an abnormality of a stator winding is detected by an antenna to detect an abnormality of the stator winding. A rotation characterized in that an antenna is buried in a coil support ring that supports the end of the stator winding protruding outside, at a position that interlinks with a magnetic field generated by a high-frequency current propagating through the stator winding. Electric machine abnormality detection device.