JP5961462B2 - Insulation diagnosis method for rotating electrical machines - Google Patents

Description

The present invention relates to insulation diagnosis how the rotary electric machine, for example, the insulation diagnosis how suitable rotary electric machine insulation diagnosis of formed stator coil mica layer such as an induction motor or a generator and fixed with resin Related.

  In a conventional stator coil insulation system of a rotating electric machine, the maximum partial discharge charge (a value of the partial discharge charge generated at a frequency of about once per cycle of applied voltage at a normal voltage) and the dielectric loss tangent are represented. It is known to estimate the remaining life of an insulator by monitoring the aging of the absolute value of the characteristic.

  For example, Patent Document 1 discloses a method for monitoring insulation of an electric machine during operation. As an evaluation index thereof, a maximum discharge charge amount, a total charge amount, an average discharge current, a discharge generation phase-charge amount-generation frequency characteristic are shown. It is described that the abnormality in the insulator can be accurately evaluated by using it.

JP 2000-206213 A

  However, in the above-described prior art, with the diversification of the insulation system, when the defect progresses in the stator coil insulation system in which mica is fixed with resin, the mica inhibits the progress direction, and the progress direction is the electric field. Sometimes it did not always match the direction. For this reason, there is a problem that it is difficult for a correlation between the maximum partial discharge charge amount, which is one of the conventional diagnostic indexes, and the degree of deterioration to appear, and it is difficult to accurately evaluate the state of insulation deterioration of the stator coil.

The present invention has been made in view of the above points, and an object is to provide an insulation diagnosis how the rotary electric machine insulation deterioration state of the stator coils can be accurately evaluated.

In order to achieve the above object, the method of diagnosing insulation of a rotating electrical machine according to the present invention is a part of the applied voltage obtained by continuously boosting or stepping down the voltage applied to the stator coil of the rotating electrical machine or combining boosting and stepping down. An operation for acquiring the relationship between the discharge charge amount and comparing the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount expressed by the natural logarithm of the acquired partial discharge charge and the applied voltage with a predetermined set value. Process, when diagnosing the insulation deterioration of the stator coil based on the result of this calculation process ,
Of the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount expressed in the natural logarithm of the partial discharge charge amount with respect to the acquired applied voltage, the portion of the applied voltage at which the partial discharge charge amount differential value increases from the background level An applied voltage (first peak) at which the discharge charge amount differential value is maximum, and a voltage region surrounded by an ascending line and a descending line of the partial discharge charge amount differential value in a region that is half the first peak value. Based on the width (half-value width), the insulation deterioration level of the stator coil is diagnosed,
Alternatively, among the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount represented by the natural logarithm of the partial discharge charge amount with respect to the acquired applied voltage, the applied voltage at which the partial discharge charge amount differential value increases from the background level And the voltage region (second peak) in which the partial discharge charge differential value increases at an applied voltage higher than the first peak. If detected, evaluate as dangerous level,
Alternatively, among the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount represented by the natural logarithm of the partial discharge charge amount with respect to the acquired applied voltage, the applied voltage at which the partial discharge charge amount differential value increases from the background level An applied voltage (first peak) at which the partial discharge charge amount differential value is maximum, and a voltage region (second peak) in which the partial discharge charge amount differential value increases at an applied voltage higher than the first peak. Based on the applied voltage that maximizes the partial discharge charge amount differential value of the first peak and the first peak value of the voltage region surrounded by the rising and falling lines of the partial discharge charge amount differential value. When the width of the half area (half width) is larger than the preset value of the applied voltage and the half value width, and the second peak is not detected, it is evaluated as a monitoring level. And

  According to the present invention, there is an effect that the insulation deterioration state of the stator coil can be accurately evaluated.

It is sectional drawing which shows the example of the rotary electric machine to which this invention is applied. FIG. 2 is a partial perspective view showing a cross section of a part of a stator coil constituting the rotating electrical machine of FIG. 1. It is a block diagram which shows Example 1 of the insulation diagnostic apparatus of the rotary electric machine of this invention. It is a figure which shows the diagnostic flow by the insulation diagnostic apparatus of FIG. It is a characteristic view which shows the calculation result of the thermal deterioration at the time of using the differential value with respect to the applied voltage of the partial discharge charge amount made into the natural logarithm display in the calculation method of the insulation diagnostic apparatus of this invention. It is a characteristic view which shows the calculation result of the mechanical deterioration at the time of using the differential value with respect to the applied voltage of the partial discharge charge amount displayed in the natural logarithm for the calculation method of the insulation diagnostic apparatus of this invention. It is a characteristic view which shows an example of the measurement result of the thermal deterioration at the time of using the differential value with respect to the applied voltage of the partial discharge charge amount made the natural logarithm display to the calculation method of the insulation diagnostic apparatus of this invention. It is a characteristic view which shows an example of the measurement result of mechanical deterioration at the time of using the differential value with respect to the applied voltage of the partial discharge charge amount made into the natural logarithm display for the calculation method of the insulation diagnostic apparatus of this invention. It is the schematic diagram after the thermal deterioration of the insulating layer in the stator coil to which this invention is applied. It is a schematic diagram after mechanical deterioration of the insulating layer in the stator coil to which the present invention is applied. It is a figure which shows the diagnostic flow in the insulation diagnostic apparatus of Example 1 of this invention. It is a figure which shows the diagnostic flow of Example 2 of this invention. It is a block diagram which shows Example 3 of the insulation diagnostic apparatus of the rotary electric machine of this invention. It is a figure which shows the diagnostic flow by the insulation diagnostic apparatus of FIG. It is a block diagram which shows Example 4 of the insulation diagnostic apparatus of the rotary electric machine of this invention. It is a figure which shows the diagnostic flow by the insulation diagnostic apparatus of FIG. It is a figure which shows the diagnostic flow of Example 5 of this invention.

Hereinafter, an insulation diagnosis how the rotary electric machine of the present invention will be described with reference to the embodiments shown. Note that the same reference numerals are used for the same components in each drawing.

  First, before describing an embodiment of the present invention, the structure of a rotating electrical machine will be briefly described with reference to FIGS.

  FIG. 1 shows an example of a rotating electrical machine to which the present invention is applied. As shown in the figure, the rotating electrical machine 1 is roughly composed of a rotor 2 and a stator 3. As shown in FIG. 2, the stator 3 includes a stator iron core 4, an iron core slot 5, and a stator coil 6. The stator coil 6 includes an upper coil 6a and a bottom coil 6b. In order to secure a space between the wedge 7 and the upper bottom coil for fixing 6 to the iron core slot 5, an insulating member spacer 8 is arranged. The stator coil 6 is electrically connected outside the stator core 4.

  As shown in FIG. 2, the stator coil 6 includes a plurality of strands 9 a subjected to strand insulation 10, and the strands 9 a are bundled and bundled with an insulation stuffing 11 so as to be integrated. The main insulation layer 12 is formed around the wire-fixing coil 9 by winding a mica tape with a glass cloth or the like as a backing material a predetermined number of times.

  The stator coil 6 may be formed by, for example, impregnating the main insulating layer 12 with a thermosetting resin such as an epoxy resin in an impregnation tank, and then heat-curing the thermosetting resin. Some of them are formed by hot pressing a prepreg mica tape in a semi-cured state containing a thermosetting resin such as a resin.

  The stator coil 6 provided with the main insulating layer 12 having a good insulation characteristic with few defects typified by voids can be obtained by the processing steps typified above.

  The main insulating layer 12 described above is desired to be completely filled with the mica tape layer and the thermosetting resin. However, the generator coil has some defects such as voids and peeling. When a voltage equal to or higher than the partial discharge start voltage is applied to an insulating layer having voids or peeling inside, partial discharge occurs at a minute defect portion such as a void or peeling.

  In addition to the micro defects existing from the beginning in the insulating layer, micro defects are newly formed mainly by thermal and mechanical stress. It is known that when a thermal, mechanical, electrical, or other stress is applied during long-term operation, the stress develops and the dielectric breakdown voltage and mechanical strength decrease.

  FIG. 3 shows a first embodiment of the insulation diagnosis device for a rotating electrical machine according to the present invention, and FIG. 4 shows a diagnosis flow based on the calculation result of the partial discharge charge amount characteristic with respect to the applied voltage by the insulation diagnosis device.

  The insulation diagnostic device 26 of the present embodiment shown in FIG. 3 includes a voltage measurement system 22 that measures the voltage applied to the stator coil 6 and a partial discharge that is generated from the main insulating layer 12 when the voltage is applied to the stator coil 6. A partial discharge charge amount detector 23 for obtaining the partial discharge charge amount, a computer 24 for obtaining the applied voltage and the partial discharge charge amount characteristic, and an arithmetic unit 30 for performing arithmetic processing on the characteristic obtained by the computer 24 The evaluation unit 31 that evaluates insulation deterioration based on the calculation result and the display unit 25 that displays the evaluation result of the evaluation unit 31 are provided. Note that the functions of the computer 24, the calculation unit 30, the evaluation unit 31, and the display unit 25 may be integrated.

  A specific example of the insulation diagnosis method by the insulation diagnosis device 26 of the above-described embodiment will be described with reference to FIGS.

  The high voltage power source 21 for the stator coil 6 of the rotating electrical machine 1 to be diagnosed (the stator coil 6 extracted from the rotating electrical machine 1 can be in a single state). Then, an AC voltage is applied through the connection terminal 29 (step S1), and the AC voltage is boosted or lowered (step S2). At that time, the voltage applied to the stator coil 6 and the partial discharge charge amount are measured by the voltage measurement system 22 and the partial discharge charge amount detector 23 in the insulation diagnostic device 26 (step S3). Thereafter, it is determined whether or not the measurement end condition is satisfied (step S4). If the measurement end condition is not satisfied, the process returns to step S2 to increase or decrease the voltage and measure the partial discharge charge amount at that time (step S3).

  This is repeated until the applied voltage and the partial discharge charge amount are acquired up to a predetermined voltage. If the measurement end condition is satisfied (step S4), the relationship between the applied voltage acquired by the computer 24 and the partial discharge charge amount (for a certain applied voltage) To obtain partial discharge charge amount characteristics with respect to the applied voltage (step S5). In addition, the acquisition of the partial discharge charge amount is known, for example, using detection of current or electromagnetic waves (for example, the configuration described in FIG. 4 of Japanese Patent Laid-Open No. 3-99286 is cited. ).

  For the partial discharge charge amount characteristic with respect to the applied voltage obtained by the above method, the arithmetic unit 30 in the insulation diagnostic device 26 performs arithmetic processing on the acquired characteristic (step S6). Thereafter, the evaluation unit 31 diagnoses insulation deterioration based on the obtained calculation result (step S7). The diagnosis result obtained by the above method is displayed on the display unit 25 in the insulation diagnosis device 26.

  In this embodiment, the description is based on the data at the time of step-up or step-down. However, the diagnosis may be made on the basis of data obtained by combining step-up and step-down.

  FIGS. 5A and 5B show the results when the differential value with respect to the applied voltage of the partial discharge charge amount expressed in the natural logarithm is used in the calculation method as an example.

  In FIG. 5A, when the applied voltage is increased from 0 V to a predetermined voltage, the differential value (partial discharge charge amount) rapidly increases with a significant difference from the background level, and reaches the maximum value. , A voltage region in which the voltage decreases rapidly (hereinafter referred to as the first peak 27) and a voltage region in which the differential value is substantially constant at the background level.

  The width of the applied voltage V1 at which the differential value of the first peak 27 is maximized and the half of the first peak 27 of the voltage region surrounded by the rising line and the falling line of the partial discharge charge differential value (hereinafter referred to as the width) H1 is referred to as a set value V corresponding to a preset applied voltage and a set value H corresponding to a half value width. The applied voltage V1 is lower than the set value V, and the half value width H1 is smaller than the set value H. ing.

  By adding arithmetic processing in this way, quantitative evaluation can be performed regardless of the measurer. The tendency (FIG. 5A) obtained by the measurement method and the calculation process shows the same tendency as an example of the actual measurement result when the thermal deterioration shown in FIG. 6A is given.

  This is because, as shown in FIG. 7A, peeling or voids 14 in the creeping direction (arrow P) of the mica tape 13 are generated and progressing. As the thermal deterioration progresses, peeling or voids 14 Since the degree of generation and progress tends to increase, the mechanical strength decreases due to thermal degradation, and the insulating layer is likely to crack due to vibration, electromagnetic force, centrifugal force, or the like.

  The example in FIG. 6A means that defects such as cracks are easily formed in the penetration direction (arrow R) of the insulating layer, and it is necessary to take measures such as shortening the diagnosis period. For example, it can be evaluated as a warning level.

  In FIG. 5B, when the applied voltage is increased from 0 V to a predetermined voltage, the second partial discharge charge amount differential value in the voltage region higher than the first peak 27 of the partial discharge charge amount differential value. The peak 28 appears, and there are two partial discharge charges (the first peak 27 and the second peak 28) with respect to the applied voltage.

  Thus, when the peak of two partial discharge charge amount differential values is detected, it can be estimated that mechanical deterioration is added. According to this, a quantitative evaluation can be performed without depending on the measurer.

  The tendency (FIG. 5B) obtained by the measurement method and the arithmetic processing described above is the same as the example of the actual measurement result when the mechanical deterioration shown in FIG. 6B is given. This tendency is due to the fact that, as shown in FIG. 7B, defects such as peeling or void 14 are bonded and progressed through micro cracks 15 or cracks 15 that progress in the penetration direction of the insulating layer. .

  This defect that progresses in the penetration direction of the insulating layer is a fatal defect for the insulating layer, and is likely to cause a significant decrease in the insulating performance represented by the breakdown voltage. it can.

  FIG. 8 shows an insulation deterioration diagnosis flow summarizing these.

As shown in the figure, the insulation deterioration diagnosis flow of the present embodiment determines whether the first peak 27 and the second peak 28 are detected in step S2 from the calculation result (step S1) in the calculation unit 30; When the first peak 27 and the second peak 28 are detected, the risk level (detailed diagnosis is necessary) is evaluated in step S3, and the first peak 27 and the second peak 28 are detected in step S2. the If not, if the applied voltage V1 and the half width H1 of the first peak 27 in step S4 is equal to or less than the set value, evaluates the alert level (countermeasure necessity of such diagnosis period shorter) at step S 5, step If the applied voltage V1 and the half-value width H1 of the first peak 27 are equal to or larger than the set value in S4, it is evaluated as a monitoring level (no problem at present, regular monitoring is continued) in Step S6.

  Thus, in the insulation deterioration diagnosis of the present embodiment, the applied voltage V1 and the half width H1 at which the partial discharge charge amount differential value of the first peak 27 is maximum are larger than the preset set values (V and H). When the second peak does not exist, the deterioration due to heat and mechanical force applied to the insulating layer is small, which indicates that there is no problem at the present time. For this reason, since it is thought that periodic diagnosis should be continued, the monitoring level is evaluated as described above, for example.

  As described above, according to the present embodiment, the partial discharge in which the degradation phenomenon due to the formation and progress of minute defects, which is difficult to appear in the absolute value of the characteristic represented by the conventional maximum partial discharge charge amount, is displayed in the natural logarithm. Since it is possible to evaluate based on the differential value of the amount of charge with respect to the applied voltage, regardless of the measurer, capture the deterioration phenomenon that rapidly deteriorates the insulation performance represented by the breakdown voltage that occurs with the connection of minute defects Therefore, it is possible to provide an insulation diagnosis technique capable of diagnosing the remaining insulation life, and an effect of accurately evaluating the insulation deterioration state of the stator coil can be obtained.

  The present embodiment is an insulation diagnosis method that enables more detailed insulation diagnosis with the insulation diagnosis apparatus 26 shown in FIG. 3 of the first embodiment.

  FIG. 9 shows an example of a diagnosis flow in the insulation diagnosis method for rotating electrical machines of the present invention.

  As shown in the figure, in step 1, the measurement end voltage V, the step-up / step-down rate v per second, the voltage and the partial discharge charge amount data measurement interval Δt are set in the computer 24, and the computer 24 uses the voltage measurement system 22. By issuing a command synchronized with the partial discharge charge amount detector 23, the partial discharge charge amount characteristic with respect to the applied voltage can be automatically recorded by the computer 24.

  Note that the frequency of occurrence of the partial discharge charge to be measured may be arbitrarily set. As an example, when the commercial frequency is 50 Hz, the generation frequency level is 50 pulses / second, and when the commercial frequency is 60 Hz, the generation frequency is 60 pulses / second, that is, the occurrence frequency is one or more times per cycle of the applied voltage. When the signal is acquired as a partial discharge charge amount, noise can be effectively removed. In addition, when the time interval Δt for measuring the voltage and the partial discharge charge amount is about 0.5 seconds and the step-up or step-down speed v per second is about 0.1 kV / second, the balance between the number of data and the evaluation accuracy is adequate. I have confirmed that I can keep it.

  After the above setting in step S1, an AC voltage is applied to the measurement target (step S2), and the AC voltage is boosted or lowered under the condition of ΔV in step S3. At that time, the information on the applied voltage and the partial discharge charge amount is synchronized among the three devices (voltage measurement system 22, partial discharge measurement system 23, and computer 24) by GPIB (General Purpose Interface Bus) or the like. . Using the computer 24, the voltage measurement system 22 and the partial discharge measurement system 23, a command is issued from the computer 24 to the voltage measurement system 22 and the partial discharge measurement system 23, and the measurement data of the voltage and the partial discharge charge amount are set as described above. Each piece of information is recorded at a measurement interval of Δt (step S4), and is sequentially stored in the computer 24 (step S5).

  Next, it is determined whether or not the measurement end voltage is reached in step S6. If it is not the measurement end voltage, the flow returns to step S3 and the flow up to step S6 is repeated. When the measurement is completed in step S6, the partial discharge charge amount characteristic with respect to the applied voltage is acquired based on the measurement result stored in the computer 24 (step S7), and the calculation unit is based on the relationship between the applied voltage and the partial discharge charge amount. At 30, the calculation process is performed. The partial discharge charge amount characteristics with respect to the applied voltage may be displayed. The acquired data may be displayed at any time.

  The calculation unit 30 acquires a differential value with respect to the applied voltage of the partial discharge charge amount displayed in the natural logarithm (step S8). The differential value may be derived from an applied voltage of an arbitrary number of points and a partial discharge charge amount expressed in a natural logarithm. As an example, if the amount of partial discharge charge expressed logarithmically with the applied voltage is about 10 points, the evaluation can be performed with high accuracy.

  Then, based on the obtained calculation result, the evaluation part 31 makes a diagnosis, and the result is displayed on the display part 25 (step S9). Note that the functions of the computer 24, the calculation unit 30, the evaluation unit 31, and the display unit 25 may be integrated.

  According to the present embodiment, the same effect as that of the first embodiment can be obtained, and the data of the applied voltage and the partial discharge charge amount can be recorded in more detail than the first embodiment, and more reliable. A highly reliable insulation diagnosis method can be provided.

  The present embodiment is an insulation diagnostic apparatus and insulation diagnosis method described in the first and second embodiments. The insulation diagnosis apparatus and insulation diagnosis method for a rotating electrical machine have the function of removing noise and extracting a significant signal for insulation diagnosis. It is.

  FIG. 10 shows an example of the configuration of the insulation diagnosis apparatus according to the present embodiment, and FIG. 11 shows a diagnosis flow in the insulation diagnosis method according to the present embodiment. In this embodiment, the description is based on the data at the time of step-up or step-down. However, the data may be based on a combination of step-up and step-down.

  The insulation diagnostic apparatus 26 of this embodiment shown in FIG. 10 has a configuration in which a noise removal / signal extraction unit 32 is added between the calculation unit 30 and the evaluation unit 31 of the configuration of FIG. Yes. That is, with respect to the differential value for the applied voltage of the partial discharge charge amount in the natural logarithm display obtained by the method described in the first and second embodiments, in the noise removal / signal extraction unit 32 added in the present embodiment, A signal that is significant for diagnosis is extracted.

  As an example of the noise removal / signal extraction method, noise separation based on the applied voltage phase, a threshold value of a signal level is set in advance for the differential value, and the differential value is set in advance at a plurality of points. When it does not exceed the level, it is performed by a method such as processing as noise.

  Noise removal / signal extraction can be performed more effectively by combining not only one but a plurality of noise removal / signal extraction. Based on the result of noise removal and signal extraction, the evaluation unit 31 performs a diagnosis, and the result is displayed on the display unit 25. Note that the functions of the computer 24, the calculation unit 30, the noise removal / signal extraction unit 32, the evaluation unit 31, and the display unit 25 may be integrated.

  FIG. 11 shows a diagnosis flow in the insulation diagnosis method using the insulation diagnosis apparatus 26 of the present embodiment.

  The diagnosis flow of this embodiment shown in the figure has a configuration in which the noise removal / signal extraction processing of step 10 is added after step S8 of the diagnosis flow described in FIG. 9 of the second embodiment. Other flows are the same as those in FIG.

  According to the present embodiment, the same effect as that of the second embodiment can be obtained, noise can be removed, and a significant signal can be extracted for diagnosis, and a highly reliable diagnosis result can be obtained. Can provide.

  In the present embodiment, the second peak 28 shown in FIG. 5 (b) is applied to the stator coil 6 determined to be a dangerous level in the insulation diagnosis apparatus and the insulation diagnosis method described in Embodiments 1, 2, and 3. The mechanical deterioration level is evaluated by using the applied voltage V2 that maximizes the differential value of and the half width H2 of the second peak 28 in the voltage region surrounded by the rising and falling lines of the partial discharge charge amount differential value. An insulation diagnosis method and an insulation diagnosis device.

  FIG. 12 shows an example of the configuration of the insulation diagnostic device 26 of the present embodiment.

  The insulation diagnostic apparatus 26 of this embodiment shown in the figure has a configuration in which a level determination unit 33 is added between the evaluation unit 31 and the display unit 25 of the configuration of FIG. That is, with respect to the first peak 27 and the second peak 28 obtained by the evaluation unit 31, the level determination unit 33 extracts a preset index for diagnosis, performs diagnosis based on the index, and results thereof. Is displayed on the display unit 25. Note that the functions of the computer 24, the calculation unit 30, the noise removal / signal extraction unit 32, the evaluation unit 31, the level determination unit 33, and the display unit 25 may be integrated.

  FIG. 13 shows a diagnosis flow in the insulation diagnosis method using the insulation diagnosis device 26 of the present embodiment.

  Usually, in the mechanical deterioration, it has been confirmed that the applied voltage V2 at which the differential value of the second peak 28 is maximum decreases as the mechanical force increases. This is because micro cracks that progress in the penetration direction of the insulating layer and defects such as delamination and voids through the cracks are combined and progress.

  Therefore, in this embodiment, when the evaluation unit 31 evaluates the danger level, the level determination unit 33 uses the applied voltage V2 that maximizes the differential value of the second peak 28 as an index, and the second peak. 28 half-value widths H2 are extracted and the deterioration level is determined.

  That is, as shown in FIG. 13, in the insulation deterioration diagnosis flow of this embodiment, the applied voltage V1 at which the differential value of the first peak 27 is maximized is set in step S2 from the calculation result (step S1) in the calculation unit 30. It is determined whether or not the value is equal to or less than the value, and if V1 is equal to or less than the set value, the applied voltage V2 that maximizes the differential value of the second peak 28 and the half width H2 of the second peak 28 are observed (step 3). If V2 and H2 are not observed, it is evaluated as a warning level (requires measures such as shortening the diagnosis period) in step 4, and if V2 and H2 are observed in step S3, a risk level (detailed diagnosis including sampling inspection) is performed in step S5. Evaluate).

  Next, if the applied voltage V1 at which the differential value of the first peak 27 is maximum is not less than the set value in step S2, it is determined in step S6 whether the half width H1 of the first peak 27 is less than or equal to the set value. If H1 is less than or equal to the set value, V2 and H2 are observed in step S7, and if V2 and H2 are not observed, they are evaluated as a warning level (requires countermeasures such as shortening the diagnosis period) in step 8, and V2 and H2 are determined in step S7. If H2 is observed, it is evaluated as a danger level (detailed diagnosis including sampling inspection) in step S9.

  Further, if the applied voltage V1 at which the differential value of the first peak 27 is maximum in step S6 is not less than the set value, the applied voltage V2 and the second peak at which the differential value of the second peak 28 is maximum in step S10. When the half width H2 of 28 is observed and V2 and H2 are observed, it is evaluated at step S11 as a dangerous level (detailed diagnosis including sampling inspection), and if V2 and H2 are not observed in step S10, it is determined in step S12. Evaluated as a monitoring level (no problem at present. Regular monitoring continued).

  In the present embodiment, either diagnosis using one kind of index or diagnosis combining a plurality of indices may be performed.

  By diagnosing these indicators in combination of one or more, it becomes possible to evaluate the formation and progress of cracks that progress in the penetration direction of the insulating layer due to mechanical force. Further, if the measurement result is stored in the computer 24, it is possible to grasp the secular change and estimate the time of the life limit. In addition, it is possible to estimate the remaining life according to each device having a different deterioration rate due to the operating condition.

  According to the present embodiment, it is possible to evaluate the mechanical deterioration level as well as to obtain the same effect as that of the third embodiment. Therefore, an insulation diagnosis technique that further subdivides the danger level is provided. can do.

  In this embodiment, in the insulation diagnosis apparatus 26 of FIG. 3 described in the first embodiment, an increase or decrease amount of the partial discharge charge amount with respect to a predetermined voltage increase or decrease is used as a calculation method, and insulation deterioration is based on the result. It is a method of diagnosing.

  FIG. 14 shows an example of a diagnosis flow in the insulation diagnosis method for a rotating electrical machine according to this embodiment.

  An AC voltage is applied from the high voltage power source 21 to the stator coil 6 of the rotating electrical machine 1 to be diagnosed via the connection terminal 29 (step S1), and the AC voltage is boosted or lowered (step S2). At that time, the voltage applied to the stator coil 6 and the partial discharge charge amount are measured by the voltage measurement system 22 and the partial discharge charge amount detector 23 in the insulation diagnostic device 26 (step S3). Thereafter, it is determined whether or not the measurement end condition is satisfied (step S4). If the measurement end condition is not satisfied, the process returns to step S2 to increase or decrease the AC voltage and measure the partial discharge charge amount at that time (step S3).

  This is repeated until the applied voltage and the partial discharge charge amount are acquired up to a predetermined voltage. If the measurement end condition is satisfied (step S4), the relationship between the applied voltage acquired by the computer 24 and the partial discharge charge amount (for a certain applied voltage) To obtain partial discharge charge amount characteristics with respect to the applied voltage (step S5).

  With respect to the partial discharge charge amount characteristics with respect to the applied voltage obtained by the above method, a voltage increase range used for the arithmetic processing is set in advance, and the relationship between the applied voltage obtained by the method described in Example 1 and the partial discharge charge amount is shown. Based on this, the amount of increase in the partial discharge charge amount with respect to the set voltage increase width is derived (step S6), and thereafter, the evaluation unit 31 diagnoses insulation deterioration based on the obtained calculation result (step S7). The diagnosis result obtained by the above method is displayed on the display unit 25 in the insulation diagnosis device 26.

  Diagnosis may be made based on a combination of step-up and step-down to the applied voltage and the partial discharge charge amount of the present embodiment.

  According to this embodiment, it is possible to provide an insulation diagnosis method capable of quantitatively diagnosing insulation deterioration without depending on a measurer as well as obtaining the same effect as that of Embodiment 1. Can do.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Rotary electric machine, 2 ... Rotor, 3 ... Stator, 4 ... Stator iron core, 5 ... Iron core slot, 6 ... Stator coil, 6a ... Upper coil, 6b ... Bottom coil, 7 ... Wedge, 8 ... Insulating member Spacer, 9 ... stranding coil, 9a ... strand, 10 ... strand insulation, 11 ... insulation padding, 12 ... main insulation layer, 13 ... mica tape, 14 ... peeling or void, 15 ... crack, 21 ... high voltage Power source, 22 ... Voltage measuring system, 23 ... Partial discharge charge detector, 24 ... Computer, 25 ... Display unit, 26 ... Insulation diagnostic device, 27 ... First peak, 28 ... Second peak, 29 ... Connection terminal , 30 ... arithmetic unit, 31 ... evaluation unit, 32 ... noise removal / signal extraction unit, 33 ... level determination unit.

Claims (7)

Obtain the relationship of the partial discharge charge amount to the applied voltage obtained by continuously boosting or stepping down the voltage applied to the stator coil of the rotating electrical machine or combining boosting and stepping down, and the acquired partial discharge charge amount and applied voltage An arithmetic process for comparing the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount expressed in natural logarithm and a predetermined set value is performed, and based on the result of the calculation process, the insulation deterioration of the stator coil is reduced. When making a diagnosis ,
Of the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount expressed in the natural logarithm of the partial discharge charge amount with respect to the acquired applied voltage, the portion of the applied voltage at which the partial discharge charge amount differential value increases from the background level An applied voltage (first peak) at which the discharge charge amount differential value is maximum, and a voltage region surrounded by an ascending line and a descending line of the partial discharge charge amount differential value in a region that is half the first peak value. An insulation diagnosis method for a rotating electrical machine , wherein an insulation deterioration level of the stator coil is diagnosed based on a width (half-value width) . The insulation diagnosis method for a rotating electrical machine according to claim 1 ,
The applied voltage at which the differential value of the first peak is maximum and the half width are compared with a preset set value of the applied voltage and a set value of the half width, the applied voltage is lower than the set value, and An insulation diagnosis method for a rotating electrical machine, characterized in that when the half width is smaller than a set value, the warning level is evaluated. The insulation diagnosis method for a rotating electrical machine according to claim 1 ,
The diagnosis result of insulation deterioration of the stator coil is displayed on a display unit. The insulation diagnosis method for a rotating electrical machine according to any one of claims 1 to 3 ,
A method for diagnosing insulation of a rotating electrical machine, wherein a signal from which noise is removed is extracted from a differential value with respect to an applied voltage of a partial discharge charge amount expressed by the natural logarithm. The insulation diagnosis method for a rotating electrical machine according to claim 4,
A threshold value of a signal level is set in advance for the differential value, and when the partial discharge charge amount differential value does not exceed the preset level threshold value at a plurality of points, it is processed as noise. Insulation diagnosis method for rotating electrical machines. Obtain the relationship of the partial discharge charge amount to the applied voltage obtained by continuously boosting or stepping down the voltage applied to the stator coil of the rotating electrical machine or combining boosting and stepping down, and the acquired partial discharge charge amount and applied voltage An arithmetic process for comparing the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount expressed in natural logarithm and a predetermined set value is performed, and based on the result of the calculation process, the insulation deterioration of the stator coil is reduced. When making a diagnosis,
Of the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount expressed in the natural logarithm of the partial discharge charge amount with respect to the acquired applied voltage, the portion of the applied voltage at which the partial discharge charge amount differential value increases from the background level An applied voltage (first peak) in which the discharge charge amount differential value is maximum and a voltage region (second peak) in which the partial discharge charge amount differential value increases at an applied voltage higher than the first peak are detected. An insulation diagnosis method for a rotating electrical machine, characterized in that if it is detected, it is evaluated as a danger level . Obtain the relationship of the partial discharge charge amount to the applied voltage obtained by continuously boosting or stepping down the voltage applied to the stator coil of the rotating electrical machine or combining boosting and stepping down, and the acquired partial discharge charge amount and applied voltage An arithmetic process for comparing the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount expressed in natural logarithm and a predetermined set value is performed, and based on the result of the calculation process, the insulation deterioration of the stator coil is reduced. When making a diagnosis,
Of the partial discharge charge amount differential value with respect to the applied voltage of the partial discharge charge amount expressed in the natural logarithm of the partial discharge charge amount with respect to the acquired applied voltage, the portion of the applied voltage at which the partial discharge charge amount differential value increases from the background level Based on the applied voltage (first peak) where the discharge charge amount differential value is maximized and the voltage region (second peak) where the partial discharge charge amount differential value increases at an applied voltage higher than the first peak. In addition, the applied voltage that maximizes the partial discharge charge amount differential value of the first peak and the half of the first peak value of the voltage region surrounded by the rising and falling lines of the partial discharge charge differential value. When the width (half width) of the region is larger than the preset value of the applied voltage and the preset half value width, and the second peak is not detected, it is evaluated as a monitoring level. Rotating electric machine Edge diagnostic methods.

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