JP2018200179A - Partial discharge monitoring apparatus and partial discharge monitoring method for rotary electric machine - Google Patents

Abstract

To provide a partial discharge monitoring apparatus and a partial discharge monitoring method for a rotary electric machine capable of detecting accurately the partial discharge generated at a stator coil winding of the rotary electric machine without suffering effects of high frequency noises.SOLUTION: A first ozone detecting unit 41, 42 for detecting an ozone concentration of the air flowing into a coil 20 of a rotary electric machine 10, a second ozone detecting unit 43, 44 for detecting an ozone concentration of the air surrounding the coil or the air flowing out from the periphery of the coil, and a partial discharge monitoring unit 51 for monitoring the partial discharge generation state by comparing a first ozone concentration detected by the first ozone detecting unit with a second ozone concentration detected by the second ozone detecting unit, are provided.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a partial discharge monitoring device and a partial discharge monitoring method for a rotating electrical machine that monitor partial discharge of the rotating electrical machine.

  A high-voltage rotating electrical machine is a device that is allowed to generate partial discharge during operation because an inorganic material such as mica having partial discharge resistance is used as an insulator. However, the partial discharge gradually erodes the insulator with the passage of years of operation and may eventually lead to equipment failure (insulation breakdown). Accordingly, partial discharge monitoring technology has been developed that detects the level of occurrence of partial discharge in a rotating electric machine that is in operation and promotes maintenance and renewal before failure.

  In this partial discharge monitoring technique, there are a method of measuring while rotating the rotating electric machine and a method of measuring during the operation. In the method of measuring after stopping operation, a test equivalent to the shipping test is performed by applying a voltage to a stationary rotating electrical machine using an external power source. This method generates the cost of stopping the equipment and the cost of using an externally powered vehicle that can perform an insulation test. In contrast to this method, a method of measuring partial discharge during operation has been developed as a low-cost method (see, for example, Patent Documents 1 and 2). In Patent Documents 1 and 2, a partial discharge is detected by attaching a sensor that detects electromagnetic waves and high-frequency currents to a rotating electric machine that is in operation.

  Patent Document 1 includes an insulation diagnostic device to which a detection signal detected by a partial discharge detection unit having a partial discharge detection antenna that detects partial discharge of a rotating electrical machine is input. By comparing the detection signal with the correlation between the partial discharge intensity stored in the database and the dielectric breakdown value, the insulation deterioration of the rotating electrical machine is determined. In Patent Document 1, since electromagnetic waves due to partial discharge hardly leak outside the rotating electric machine frame, the partial discharge detection antenna needs to be attached to the rotating electric machine inside in advance.

  In Patent Document 2, a detection coil that is inductively coupled to a stator winding is provided, and a detection pulse corresponding to a high-frequency current based on a partial discharge generated in the stator winding that propagates from the detection coil to the stator winding is provided. The detected pulse is transmitted to a deterioration determination circuit provided outside the rotating electrical machine to determine whether there is an abnormality in the rotating electrical machine. Also in this patent document 2, it is necessary to attach a detection coil to the inside of a rotary electric machine in advance.

JP 2012-7924 A JP-A-4-299052

  However, in the prior art described in Patent Documents 1 and 2, high-frequency current based on partial discharge generated in a stator winding of a rotating electrical machine is detected by a detection coil, or partial discharge intensity is directly detected by a partial discharge detection antenna. It is detected. For this reason, it is possible to detect partial discharge with high accuracy in an ideal environment without high-frequency noise. However, in an actual environment, power supply systems and peripherals that generate high-frequency noise such as high-frequency switching around the rotating electrical machine. In many cases, devices are arranged, and the frequency band between the high-frequency noise and the high-frequency signal due to partial discharge is close, and a technique for discriminating both signals is required. Noise removal methods such as filter processing and signal processing may attenuate even partial discharge signals, and no industry standard method has yet been established.

Non-electrical methods have also been studied as methods that are not affected by switching noise. The technique is a technique for detecting light and decomposition products, which are secondary reactions accompanying the discharge phenomenon. However, these methods are methods for testing and evaluating the inside of the rotating electrical machine by opening it to a visible state, and are not established as a partial discharge monitoring method for the rotating electrical machine during operation.
In devices other than rotating electrical machines, a method of detecting the decomposition gas concentration due to partial discharge has been put into practical use with a sealed stationary device using an insulating gas such as SF6 gas. However, a partial discharge monitoring method using cracked gas has not been put to practical use for high-voltage equipment that circulates atmospheric air such as rotating electrical machines.

  Therefore, the present invention has been made by paying attention to the problems of the prior art described in Patent Documents 1 and 2, and the partial discharge generated in the stator winding of the rotating electrical machine is affected by high-frequency noise. It is an object of the present invention to provide a partial discharge monitoring device and a partial discharge monitoring method for a rotating electrical machine that can be detected with high accuracy.

  In order to achieve the above object, one aspect of a partial discharge monitoring device for a rotating electrical machine according to the present invention includes a first ozone detector that detects an ozone concentration of air flowing into a coil of the rotating electrical machine, and air around the coil. Alternatively, the second ozone detector that detects the ozone concentration of the air flowing out from the periphery of the coil is compared with the first ozone concentration detected by the first ozone detector and the second ozone concentration detected by the second ozone detector. And a partial discharge monitoring unit for monitoring the partial discharge occurrence status.

  According to one aspect of the partial discharge monitoring method for a rotating electrical machine according to the present invention, the step of detecting the ozone concentration of the air flowing into the coil of the rotating electrical machine as the first ozone concentration and the air around the coil or the periphery of the coil. The step of detecting the ozone concentration of the flowing out air as the second ozone concentration, the ozone concentration increase amount is calculated based on the first ozone concentration and the second ozone concentration, and the partial discharge is generated based on the calculated ozone concentration increase amount. Monitoring the situation.

  According to one aspect of the present invention, by detecting the ozone concentration not caused by partial discharge contained in the air flowing into the coil and the ozone concentration generated by partial discharge generated by the coil of the rotating electrical machine, It is possible to accurately monitor the occurrence of partial discharge without being affected.

It is sectional drawing which shows 1st Embodiment of the partial discharge monitoring apparatus of the rotary electric machine which concerns on this invention. It is a flowchart which shows an example of the partial discharge monitoring process procedure performed with a partial discharge monitoring part. It is a characteristic diagram which shows the relationship between ozone concentration and elapsed time. It is a characteristic diagram with which it uses for description of lifetime determination and remaining lifetime estimation. It is a characteristic diagram which shows the relationship between the ozone concentration of the site | part from which a rotary electric machine differs, and elapsed time. It is sectional drawing which shows 2nd Embodiment of the partial discharge monitoring apparatus of the rotary electric machine which concerns on this invention. It is sectional drawing which shows 3rd Embodiment of the partial discharge monitoring apparatus of the rotary electric machine which concerns on this invention.

  Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

Further, the embodiment described below exemplifies an apparatus and a method for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, The layout is not specified as follows. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.
First, a first embodiment of a partial discharge monitoring apparatus for a rotating electrical machine representing one aspect of the present invention will be described with reference to FIG.

First, a rotating electrical machine to which the present invention can be applied will be described. The rotating electrical machine 10 includes a fully-closed rotating electrical machine body 11 and an outer frame 31 that covers the outer peripheral side of the rotating electrical machine body 11.
The rotating electrical machine main body 11 includes a rotating shaft 14 rotatably supported by bearings 13a and 13b on end plate portions 12a and 12b formed at both ends of the sealing frame 12, and a rotor fixed to the rotating shaft 14. The iron core 15 and the rotor iron core 15 are opposed to each other with a predetermined gap, and the stator iron core 16 is fixed to the inner peripheral surface of the sealing frame 12.

A circulating fan 17 is fixed to the rotating shaft 14 at an end protruding from the bearing 13a, and a coupling 18 is fixed to an end protruding from the bearing 13b.
A stator coil 20 insulated by an insulator 19 is wound around the stator core 16.
The stator coil 20 is supplied with power from a three-phase cable 22 through a terminal box 21.
The outer frame 31 is formed with an air inlet 32 at a position facing the circulation fan 17, and an exhaust port 33 is formed at the upper end of the bearing 13 b, between the air inlet 32 and the exhaust port 33. A cooling body 34 that is in contact with the stator core 16 is disposed on the outer peripheral side of the stator core 16. For this reason, when the rotating electrical machine 10 is driven to rotate, the circulation fan 17 rotates, and the circulation fan 17 sucks outside air from the intake port 32, cools the cooling body 34, and then exhausts it from the exhaust port 33.

In the present embodiment, the first ozone detector 41 is detachably disposed on the bottom side inside the outer frame 31 so as to be in contact with the air sucked from the intake port 32, and is disposed on the inner peripheral surface side of the cooling body 34. The first ozone detector 42 is also arranged. These first ozone detectors 41 and 42 detect the ozone gas concentration before passing through the stator coil 20 of the rotating electrical machine main body 11.
On the other hand, the second ozone detectors 43 and 44 are detachably disposed in the frame 12 of the rotating electrical machine main body 11 on the bottom side near the protruding end of the stator coil 20 protruding in the axial direction from the stator core 16. To do. These second ozone detectors 43 and 44 detect the ozone gas concentration around the stator coil 20.

Here, each of the first ozone detectors 41 and 42 and the second ozone detectors 43 and 44 can use an ozone absorber such as zeolite or silica gel, which is a material that absorbs ozone gas.
Moreover, in this embodiment, the partial discharge monitoring part 51 which measures the ozone absorption amount of the 1st ozone detection parts 41 and 42 and the 2nd ozone detection parts 43 and 44, and monitors a partial discharge is provided. The partial discharge monitoring unit 51 monitors the partial discharge by measuring the ozone concentration detected by the first ozone detection units 41 and 42 and the second ozone detection units 43 and 44.

The partial discharge monitoring unit 51 is based on the ozone concentration measuring unit 52 that measures the ozone concentrations of the first ozone detecting units 41 and 42 and the second ozone detecting units 43 and 44, and the ozone concentration measured by the ozone concentration measuring unit 52. And a discharge deterioration monitoring unit 53 for monitoring the partial discharge deterioration.
The ozone concentration measuring unit 52 takes out and collects the ozone absorbing material constituting the collected first ozone detecting units 41 and 42 and the second ozone detecting units 43 and 44 during the periodic inspection of the rotating electrical machine 10. The ozone concentration accumulated by deaeration with nitrogen gas is measured, and the measurement result is output to the discharge deterioration monitoring unit 53.

The discharge deterioration monitoring unit 53 is configured by an arithmetic processing unit such as a microcomputer, for example, and each of the progress of partial discharge, the progress acceleration, the life, and the remaining life based on the ozone concentration detected by each of the ozone detectors 41 to 44. Make a decision.
Specifically, the discharge deterioration monitoring unit 53 executes a discharge deterioration monitoring process shown in FIG. In the discharge deterioration monitoring process, first, in step S1, the first ozone concentration measured values OV11 and OV12 detected by the first ozone detectors 41 and 42 measured by the ozone measuring device are read, and the second ozone detector 43 and After reading the second ozone concentration measurement values OV21 and OV22 detected at 44, the process proceeds to step S2.

  In this step S2, the average value MOV of the first ozone concentration measurement values OV11 and OV12 is calculated, and then the process proceeds to step S3, where the calculated average value MOV is used as the ozone concentration measurement value OV21 of the second ozone detectors 43 and 44. Then, the ozone concentration increase amounts UOV21 (n) (= OV21−MOV) and UOV22 (n) (= OV22−MOV) are calculated by subtracting them individually from OV22, and the process proceeds to step S4.

In this step S4, the ozone concentration increase amounts UOV21 (n-1) and UOV22 () previously calculated from the ozone concentration increase amounts UOV21 (n) and UOV22 (n) calculated based on the following equations (1) and (2). After subtracting n-1), the ozone concentration increase change amounts ΔUOV21 and ΔUOV22 are calculated, and then the process proceeds to step S5.
ΔUOV21 = UOV21 (n) −UOV21 (n−1) (1)
ΔUOV22 = UOV22 (n) −UOV22 (n−1) (2)

  In step S5, the progress of partial discharge on the front side (bearing 13a side) of the rotating electrical machine main body 11 is determined based on the calculated ozone concentration increase change amount ΔUOV21. The determination of the progress of partial discharge is made based on whether or not the ozone concentration increase change amount ΔUOV21 is equal to or greater than the progress threshold ADs. When ΔUOV21 ≧ ADs, partial discharge deterioration occurs on the front side of the rotating electrical machine body 11. It judges that it has progressed, it transfers to step S6, it displays on the display part 54 that it is in the condition where the partial discharge deterioration is advancing on the front part side of the rotary electric machine main body 11, and then it transfers to step S7 To do.

  In step S7, the progress acceleration of partial discharge deterioration on the front side of the rotating electrical machine main body 11 is determined. The determination of the progress acceleration is performed by determining whether or not the ozone concentration increase change amount ΔUOV21 is equal to or greater than the progress acceleration threshold ADAs having a value larger than the progress threshold ADs, and when ΔUOV21 ≧ ADAS, It is determined that the partial discharge deterioration on the part side has progressed rapidly, and the process proceeds to step S8 to indicate that the partial discharge deterioration is rapidly progressing on the front part side of the rotating electrical machine main body 11. After the display, the process proceeds to step S9.

Further, when the determination result of step S5 is ΔUOV21 <ADs and when the determination result of step S7 is ΔUOV21 <ADAs, the process directly proceeds to step S9.
In step S9, the progress of partial discharge on the rear side (bearing 13b side) of the rotating electrical machine main body 11 is determined based on the calculated ozone concentration increase change amount ΔUOV22. The determination of the progress of partial discharge is made based on whether or not the ozone concentration increase change amount ΔUOV22 is equal to or greater than the progress threshold value ADs. When ΔUOV22 ≧ ADs, partial discharge deterioration occurs on the front side of the rotating electrical machine body 11. It judges that it has progressed, it transfers to step S10, after displaying on the display part 54 that it is in the condition where the partial discharge deterioration is advancing on the rear side of the rotary electric machine main body 11, it transfers to step S11. .

  In step S11, the progress acceleration of partial discharge deterioration on the rear side of the rotating electrical machine main body 11 is determined. This determination of the progress acceleration is performed by determining whether or not the ozone concentration increase change amount ΔUOV22 is equal to or greater than the progress acceleration threshold ADAs having a value greater than the progress threshold ADs, and when ΔUOV22 ≧ ADAS, It is determined that the partial discharge deterioration on the side has progressed rapidly, and the process proceeds to step S12 to indicate on the display unit 54 that the partial discharge deterioration is rapidly progressing on the front side of the rotating electrical machine main body 11. After the display, the process proceeds to step S13.

Further, when the determination result of step S9 is ΔUOV22 <ADs and when the determination result of step S11 is ΔUOV22 <ADAs, the process directly proceeds to step S13.
In step S13, it is determined whether or not the rotating electrical machine main body 11 has reached the equipment life. This life determination determines whether any of the ozone concentration increase amounts OUV21 and OUV22 has reached the ozone upper limit concentration (life value) OVlim, and when OUV21 ≧ OUVlim or OUV22 ≧ OUVlim, Is determined to have reached the device life, the process proceeds to step S14, the fact that the device life has been reached is displayed on the display unit 54, and the partial discharge monitoring process is terminated.

  When the determination result in step S13 is OUV21 <OUVlim or OUV22 <OUVlim, the process proceeds to step S15, where the remaining life is based on the change in the ozone concentration increase, whichever is greater of the ozone concentration increase change ΔOUV21 or ΔOUV22. Calculate the number of years. For this remaining life, create a time change approximate curve from the historical information on the amount of ozone rise up to this time, and use the usable life until the intersection of the created time conversion approximate curve and the aforementioned ozone upper limit concentration OVlim as the remaining life years Then, the process proceeds to step S16, and the partial life monitoring process is terminated after displaying the minimum or near remaining life years in the calculated remaining life years on the display unit 54.

Next, the operation of the first embodiment will be described.
The standard of the partial discharge charge allowed in the high-voltage rotating electrical machine having the above-described configuration varies depending on the insulating material and the insulating structure used. As standard standards, the normal level is defined as 3,000 pC or less, the monitoring level required is defined as 3,000 to 3,000 pC, and the danger level is defined as 3,0000 pC or more. When partial discharge occurs in the atmosphere, electrons accelerated by an external electric field collide with oxygen molecules O ₂ and dissociate into two oxygen atoms O. The oxygen atoms O and oxygen molecules O ₂ are combined to generate ozone O ₃ . From such a relationship, a strong correlation can be expected between the partial discharge charge amount and the ozone generation amount.

According to the document “Tokyo environmental data 2001 Tokyo environment 2003”, the naturally occurring ozone concentration is 27 ppd as the average concentration in the outdoor environment. The ozone concentration as a working environment is determined to be 60 ppd or less by the general environmental standards in Japan, but varies greatly depending on the date and measurement environment.
As for the ozone concentration due to the occurrence of partial discharge, the needle and plate electrode in “2014 Electrotechnical National Convention, Paper No. 6_262, Title“ Measurement of ozone concentration by partial discharge in air ”(hereinafter referred to as Reference 2). The ozone generation concentration due to partial discharge of the system has been reported. When a partial discharge charge amount of 2,000 pC is stably generated in a space of 0.125 m ³ , the ozone concentration is 25 ppd at the maximum value and 17 ppd at the stable value. When the partial discharge is stopped, the ozone concentration is halved in about 10 minutes, and it is reduced to 6ppd, which is the same as the external environment after about 30 minutes. The ozone gas concentration by discharge is at a level that is difficult to distinguish from the naturally occurring ozone gas concentration.

  Therefore, in the first embodiment, the first ozone detectors 41 and 42 absorb the ozone gas before passing through the stator coil 20 of the rotating electrical machine main body 11, and the second ozone detectors 43 and 44 fix the stator. The ozone gas around the coil 20 is absorbed. At this time, by arranging the first ozone detectors 41 and 42 and the second ozone detectors 43 and 44 on the bottom side, it is possible to reliably absorb ozone gas heavier than air.

  The first ozone detectors 41 and 42 and the second ozone detectors 43 and 44 are taken out and collected outside during a periodic inspection of the rotating electrical machine 10 with a predetermined period, and the collected first ozone detectors 41 and 42 and second By setting the ozone absorbing material constituting the ozone detectors 43 and 44 in the ozone concentration measuring unit 52 and degassing with nitrogen gas, the first ozone concentration measured value OV11, which is a measured value of the accumulated ozone concentration, is obtained. OV12 and second ozone concentration measurement values OV21 and OV22 are obtained.

Now, the average value MOV of the first ozone concentration measurement values OV11 and OV12 and the second ozone concentration measurement value OV21 measured at regular inspections of a predetermined cycle are, for example, regular inspections every year, as shown in FIG. , Change.
In this case, at time points t1 to t3, there is almost no change in the ozone concentration increase amount UOV21 (n) obtained by subtracting the average value MOV from the second ozone concentration measurement value OV21 calculated by the discharge deterioration monitoring unit 53, and the discharge of FIG. In the deterioration monitoring process, the process proceeds from step S4 to step S5, step S9, and step S13 to step S15, and as shown in FIG. 4, a time change approximate curve L1 is calculated. In this case, the time change approximate curve is calculated. Since L1 is substantially parallel to the time axis, the remaining life years cannot be calculated, and the expected remaining life years are displayed on the display unit 54.

  Thereafter, at time t4, when the ozone concentration increase amount UOV21 increases and the ozone concentration increase change amount ΔUOV21 is equal to or greater than the progress threshold value ADs, it is indicated that the partial discharge deterioration has progressed on the front side of the rotating electrical machine main body 11. 54 (step S6). Since the ozone concentration increase change amount ΔUOV21 at this time is less than the progress acceleration threshold ADAs, it is determined that the progress acceleration state is not set.

  At this time point t4, the ozone concentration increase change amount ΔUOV21 becomes equal to or greater than the progress threshold value ADs, so that the slope of the time change approximate curve L1 increases as shown in FIG. And the number of years from the time point t4 to the intersection P is calculated as the remaining life years X (step S15), and the calculated remaining life years X are displayed on the display unit 54 (step S16).

Thereafter, at time points t5 to t9, the ozone concentration increase change amount ΔUOV21 is equal to or greater than the progress threshold value ADs but is less than the progress acceleration threshold value ADAs, and the display unit 54 indicates that partial discharge deterioration is progressing. Is done.
In addition, as the remaining life years, the remaining life years X are calculated longer because the ozone concentration increase change amount ΔUOV21 becomes smaller than the ozone concentration increase change amount ΔUOV21 at time point t4 after the time point t5. From the history, the least remaining life years Xmin or the second or third remaining life years in consideration of the error are displayed on the display unit 54 as the remaining life years X.

Thereafter, when the deterioration further progresses at time t10 and the ozone concentration increase change amount ΔUOV21 becomes equal to or greater than the progress acceleration threshold ADAs, it is determined that the partial discharge deterioration is in a state of accelerating the progress (step S7). Is displayed on the display unit 54 (step S8).
If the ozone concentration increase amount UOV21 at this time exceeds the ozone concentration upper limit value OVlim as shown in FIG. 4, it is determined that the device life has been reached (step S13), and the rotating electrical machine main body 11 has reached the device life. A message to the effect is displayed on the display unit 54 to prompt the user to update the rotating electrical machine body 11 to a new rotating electrical machine body (step S14).

  In the first embodiment, the ozone concentration on the front side and the rear side of the rotating electrical machine main body 11 is measured as the ozone concentration measurement values OV21 and OV22. An example of the measurement result is shown in FIG. From the measurement result of FIG. 5, since the ozone concentration measurement value OV22 on the rear side of the rotating electrical machine main body 11 is larger than the ozone concentration measurement value OV21 on the front side at the time t1, for example, It can be understood that the partial discharge deterioration on the rear side is remarkable. After that, at time t4 to t9, it can be understood that the partial discharge deterioration on the rear side of the rotating electrical machine main body 11 is remarkable as at time t1, and the degree of progress of the partial discharge deterioration is It can be determined that the part and the rear part are substantially the same.

However, at time t10, the ozone concentration increase amount UOV21 on the front side of the rotating electrical machine body 11 becomes larger than the ozone concentration increase amount UOV22 on the rear side, and the partial discharge deterioration on the front side of the rotating electrical machine body 11 becomes significant. It can be understood that the degree of progress was also remarkable at the front side of the rotating electrical machine main body 11.
As described above, according to the first embodiment, since the partial discharge deterioration is monitored by detecting the ozone concentration inside the rotating electrical machine body 11, the partial discharge deterioration is not affected by the surrounding high frequency noise. It can be monitored accurately.

Moreover, since the ozone absorber is applied as the first ozone detectors 41 and 42 and the second ozone detectors 43 and 44, the ozone absorber is collected at every periodic inspection, and the absorbed ozone concentration is measured. The ozone concentration generated by the discharge can be accurately measured.
Furthermore, since the ozone absorbing material does not require an electric circuit or a precision structure, there is no risk of failure due to vibration and it can sufficiently withstand long-term use. In addition, since the ozone gas in the rotating electrical machine main body 11 is absorbed by the ozone absorbing material, there is an effect that the ozone concentration in the rotating electrical machine main body 11 can be reduced and deterioration of the insulator and the seal rubber material due to the ozone gas can be suppressed.

Then, the partial discharge monitoring unit 51 detects ozone from the average value of the first ozone concentration detected by the first ozone detection units 41 and 42 and the second ozone concentration detected by the second ozone detection units 43 and 44 for each periodic inspection. The concentration increase amount can be calculated, and when the ozone concentration increase amount is equal to or greater than the set value, it can be determined that partial discharge deterioration has started to occur.
After that, when the ozone concentration increase amount increases from the previous value, it can be determined that the partial discharge deterioration is progressing, and the ozone concentration increase amount is compared with the previous ozone concentration increase amount. When the increase amount becomes large, it can be determined that the progress of partial discharge deterioration is in an accelerated state.

Further, by determining whether or not the ozone concentration increase amount has reached a preset ozone concentration upper limit value, it is possible to determine whether or not the rotating electrical machine body has reached the end of its life and has become unusable.
Further, a time change approximate curve (deterioration prediction curve) L1 of the ozone concentration increase amount is created, and the remaining life years X are estimated from the intersection of this time change approximation curve (deterioration prediction curve) L1 and the ozone concentration upper limit value OVlim. Can do.

In the first embodiment, the case where the partial discharge monitoring unit 51 monitors the partial discharge deterioration of the stator coil 20 based on the ozone concentration has been described. However, the present invention is not limited to this. The monitoring unit 51 may estimate the partial discharge charge amount from the ozone concentration increase amounts UVO21 and UVO22 described above.
That is, the partial discharge charge amount is estimated by acquiring correlation data between the discharge charge amount in various partial discharge modes and the ozone concentration increase amount in the sealed space including the partial discharge, and calculating the partial discharge charge amount from the degree of ozone concentration increase.

According to the experimental result of Document 2 described above, when the partial discharge charge amount of 2,000 pC is stably generated in the space volume of 0.125 m ³ , the average ozone concentration is increased by 11 ppd. Assuming that the partial discharge charge amount and the ozone generation amount are in a proportional relationship, the partial discharge charge amount 部分 the ozone generation amount = (ozone concentration change) / (space volume) is considered.
From this experimental result,
Partial discharge charge [pC] = 0.044 × ozone concentration increase [ppd] ÷ volume [m ³ ]
Is obtained.

Using this relational expression, the partial discharge charge amount can be estimated by obtaining the internal volume [m ³ ] of the rotating electrical machine 10 and the ozone concentration increase [ppd]. By acquiring such experimental data in the high-voltage rotating electrical machine, the partial discharge charge amount can be monitored by measuring the ozone concentration increase amounts UOV21 and UOV22 inside the rotating electrical machine.
Moreover, in the said 1st Embodiment, although the case where the rotary electric machine main body 11 has a fully closed structure was demonstrated, when the rotary electric machine main body 11 is an open type, internal air of the rotary electric machine main body 11 is discharged | emitted from a discharge port. Since it is discharged, the second ozone detector may be disposed at this outlet and the ozone concentration in the rotating electrical machine main body 11 may be measured.

Next, a second embodiment of the present invention will be described with reference to FIG.
In the second embodiment, ozone detection is performed without permanently installing an ozone detection unit in the rotating electrical machine 10.
That is, in the second embodiment, as shown in FIG. 6, the first ozone detectors 41 and 42 and the second ozone detectors 43 and 44 in the first embodiment are omitted. Instead of these, ozone detector tubes 61 and 62 serving as a first ozone detector that can electrically measure the ozone concentration are arranged outside the intake port 32 and the exhaust port 33 of the outer frame 31 when measuring the ozone concentration. To do. Similarly, ozone detection pipes 63 and 64 similar to the ozone detection pipes 61 and 62 serving as the second ozone detection section are arranged in the terminal box 21 and the drain port 23 that communicate the inside and the outside of the rotating electrical machine main body 11, respectively.

  The ozone detection tubes 61 to 64 are formed of a glass tube having a diameter of about 6 mm, and a drug that changes color in response to ozone is enclosed in the glass tube. The glass tube is attached to the tip of the suction cylinder, and a certain amount of ambient air is sucked to measure the ozone concentration. The ozone concentration value can be measured immediately by reading the scale of the discolored portion.

The ozone detection tubes 61 to 64 have a sensor size that can be inserted into the insertion port of the measurement site, can measure ozone concentration without being affected by the flow velocity, and can measure low concentration. Further, it is preferable to have a configuration capable of measuring the ozone concentration immediately at the start of measurement.
Then, the ozone deterioration measured values OV11 and OV12 measured by the ozone detector tubes 61 and 62 and the ozone concentration measured values OV21 and OV22 measured by the ozone detector tubes 63 and 64 are the discharge deterioration monitoring described in the first embodiment. Input from an ozone concentration input unit 55 provided in the unit 53.

  In the second embodiment, the ozone detector tubes 61 to 64 are arranged at the intake port 32 and the exhaust port 33 of the outer frame 31 of the rotating electrical machine main body 11 at regular intervals for monitoring the partial discharge of the rotating electrical machine, respectively. The ozone detection pipes 61 and 62 measure the ozone concentration of the air flowing into the rotary electric machine 10, and the ozone detection pipes 63 and 64 measure the ozone concentration inside the rotary electric machine main body 11.

By inputting the first ozone concentration measurement values OV11, OV12, OV21, and OV22 measured by the ozone detector tubes 61, 62, 63, and 64 to the discharge deterioration monitoring unit 53, the same as in the first embodiment described above. The partial discharge deterioration can be monitored without being affected by high frequency noise.
In the second embodiment, there is no need to always arrange an ozone detector in the rotating electrical machine main body 11, and only ozone concentrations 61 and 64 are measured by disposing ozone detector tubes 61 to 64 at predetermined sites when monitoring partial discharge deterioration. Therefore, it is possible to reduce the labor of measurement compared to the first embodiment described above.

In the second embodiment, the case where the existing terminal box 21 and the drain port 23 are used as the insertion ports of the ozone detection tubes 63 and 64 for detecting the ozone concentration in the rotating electrical machine main body 11 has been described. A dedicated measurement port for measurement may be provided.
Moreover, in the said 2nd Embodiment, although the case where the rotary electric machine main body 11 has a fully closed structure was demonstrated, when the rotary electric machine main body 11 is an open type, the internal air of the rotary electric machine main body 11 is discharged | emitted from a discharge port. Since it is discharged, an ozone detector tube as a second ozone detector may be arranged at this outlet and the ozone concentration in the rotating electrical machine main body 11 may be measured.

Next, a third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, the ozone concentration inside and outside the rotating electrical machine main body 11 is always electrically measured.
That is, in the third embodiment, as shown in FIG. 7, through holes 71 and 72 are formed between the bottom of the outer frame 31 of the rotating electrical machine 10 facing the outer periphery of the circulation fan 17 and between the cooling body 34 and the exhaust port 33. The first ozone detectors 81 and 82 are disposed in the through holes 71 and 72. Similarly, through holes 73 and 74 are formed in the peripheral positions of the stator coil 20 projecting from the front and rear end portions of the stator core 16 of the rotating electrical machine main body 11, and the second ozone detector 83 is provided in the through holes 73 and 74. And 84 are arranged.

  Each of the ozone detectors 81 to 84 includes an ozone measuring valve 85 inserted into the through holes 71 to 74, and an air tube 86 having one end attached to the outside of the rotating electrical machine 10 of the ozone measuring valve 85. The electronic ozone concentration meter 87 is attached to the other end of the air tube 86. Each ozone detector 81 to 84 draws air containing a certain amount of ozone from the ozone measuring valve 85 into the air tube 86 when measuring the ozone concentration, and measures the ozone concentration of the drawn air with an electronic ozone concentration meter 87. To do. The electronic ozone concentration meter 87 directly inputs the measured ozone concentration as a digital value to the discharge deterioration monitoring unit 53.

  According to the second embodiment, when measuring partial discharge deterioration, a certain amount of air is sucked from the ozone measuring valve 85 and is sent to the electronic ozone concentration meter 87 via the air tube 86, whereby an electronic ozone concentration meter is obtained. The ozone concentration is measured at 87, and the first ozone concentration measurement values OV 11 and OV 12 and the second ozone concentration measurement values OV 21 and OV 22 are directly input to the discharge deterioration monitoring unit 53.

Therefore, by executing the discharge deterioration monitoring process shown in FIG. 2 in the discharge deterioration monitoring unit 53, it is possible to monitor the partial discharge deterioration due to the ozone measurement value as in the first embodiment.
In the third embodiment, the ozone detectors 81 to 84 are permanently installed in the rotating electrical machine 10 and the electronic ozone concentration meter 87 is provided, so that the ozone concentration measurement value is directly input to the discharge deterioration monitoring unit 53. And partial discharge deterioration can be automatically monitored. For this reason, partial discharge deterioration can be monitored at a constant period or at a desired time, and the degree of freedom in monitoring partial discharge deterioration can be improved. Also, partial discharge deterioration of the rotating electrical machine 10 can be monitored at a remote location, and an ozone detector provided in a plurality of rotating electrical machines is connected to the discharge deterioration monitoring unit 53 in a switchable manner, so that one discharge The deterioration monitoring unit 53 can remotely monitor partial discharge deterioration of a plurality of rotating electrical machines.

In the third embodiment, when the rotating electrical machine main body 11 is an open type, the ozone detector may be disposed in the internal air discharge path of the rotating electrical machine main body 11.
In the first to third embodiments, the case where the rotating electrical machine main body 11 is a fully closed type has been described. However, when the rotating electrical machine main body 11 has a circulation path that circulates internal air even in the fully closed type, the circulation path also includes ozone. It is preferable to provide a detector.

  Furthermore, in the first to third embodiments, the case where the first ozone detector is provided at two locations and the average value is calculated has been described. However, the present invention is not limited to this, and the first ozone detector is One location may be provided in the vicinity of the intake port 32 or the exhaust port 33 of the outer frame. Further, when a plurality of first ozone detectors are provided, the maximum ozone concentration measurement value may be adopted instead of the average value.

  DESCRIPTION OF SYMBOLS 10 ... Rotary electric machine, 11 ... Rotary electric machine main body, 14 ... Rotary shaft, 15 ... Rotor iron core, 16 ... Stator iron core, 17 ... Circulation fan, 19 ... Insulator, 20 ... Stator coil, 31 ... Outer frame, 32 ... intake port, 33 ... exhaust port, 34 ... cooling body, 41,42 ... first ozone detector, 43,44 ... second ozone detector, 51 ... partial discharge monitor, 52 ... ozone concentration measuring unit, 53 ... Discharge deterioration monitoring unit, 61 to 64 ... ozone detection tube, 81, 82 ... first ozone detection unit, 83, 84 ... second ozone detection unit, 85 ... valve for ozone measurement, 86 ... air tube, 87 ... electronic ozone Densitometer

Claims (10)

A first ozone detector that detects the ozone concentration of the air flowing into the coil of the rotating electrical machine;
A second ozone detector for detecting the ozone concentration of the air around the coil or the air flowing out of the coil,
A partial discharge monitoring unit that monitors a partial discharge occurrence state based on a difference value between the first ozone concentration detected by the first ozone detection unit and the second ozone concentration detected by the second ozone detection unit. Partial discharge monitoring device for rotating electrical machines.   The partial discharge monitoring device for a rotating electrical machine according to claim 1, wherein the first ozone detector and the second ozone detector are made of an ozone absorbing material.   The partial discharge monitoring apparatus for a rotating electrical machine according to claim 1, wherein the first ozone detector and the second ozone detector are configured by an ozone detector tube.   The first ozone detector and the second ozone detector include an air valve that passes through a frame of a rotating electrical machine and sucks air at a measurement site, an air tube connected to the outside of the frame of the air valve, and an air tube The partial discharge monitoring device for a rotating electric machine according to claim 1, comprising an electronic ozone concentration meter for measuring the ozone concentration of the drawn air.   The partial discharge monitoring unit monitors temporal changes in ozone concentration detected by the first ozone detection unit and the second ozone detection unit, and detects an ozone concentration increase amount based on the first ozone concentration and the second ozone concentration. The partial discharge monitoring apparatus for a rotating electrical machine according to any one of claims 1 to 4, wherein the progress of partial discharge deterioration is determined based on the increase, and the progress acceleration of partial discharge deterioration is determined from the rate of change in the ozone concentration increase amount. . A plurality of the second ozone detectors are arranged around the coil,
The partial discharge monitoring unit is a portion based on a temporal change in ozone concentration detected by the first ozone detection unit and the plurality of second ozone detection units, and a level of ozone concentration detected by the plurality of second ozone detection units. The partial discharge monitoring apparatus for a rotating electrical machine according to any one of claims 1 to 4, wherein the progress of discharge deterioration is determined.   The partial discharge monitoring unit notifies that the device life of the rotating electrical machine has been reached when the second ozone concentration detected by the second ozone detection unit has reached an allowable upper limit value. The partial discharge monitoring device for a rotating electrical machine according to the item.   The partial discharge monitoring device for a rotating electrical machine according to claim 7, wherein the partial discharge monitoring unit estimates a remaining life until the allowable upper limit value is reached from a change state of the second ozone concentration detected by the second ozone detection unit. . Detecting the ozone concentration of the air flowing into the coil of the rotating electrical machine as the first ozone concentration;
Detecting the ozone concentration of the air around the coil or the air flowing out of the coil as a second ozone concentration;
Calculating an ozone concentration increase amount based on the first ozone concentration and the second ozone concentration, and monitoring a partial discharge occurrence state based on the calculated ozone concentration increase amount;
The partial discharge monitoring method of the rotary electric machine provided with.   The partial discharge monitoring method for a rotating electrical machine according to claim 9, wherein the first ozone concentration and the second ozone concentration are detected by measuring the concentration of ozone gas absorbed by an ozone absorber.

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