JP2014006191A - Soundness diagnostic method of transformer, soundness diagnostic device thereof, and soundness diagnostic program thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to determine the presence or absence of abnormality of a winding wire of a transformer without opening and closing an upper lid of the transformer, only by using a universal device, and with less labor and time because of the determination performed in a state where the transformer is wired on a power distribution pole.SOLUTION: A leakage inductance viewed from a first winding wire of a transformer is measured in a state where the first winding wire is released and a second winding wire is connected to a load, while a short circuit is generated on the second winding wire (S1). The presence or absence of abnormality of the first winding wire is determined on the basis of the inductance value, so that the soundness of the transformer is determined (S2).

Description

  The present invention relates to a transformer health diagnostic method, a health diagnostic device, and a health diagnostic program. More specifically, the present invention relates to a technique suitable for use in determining the presence or absence of a rare short circuit or short circuit between turns in a transformer.

  In response to demands for cost reduction in maintenance and management of power distribution facilities and industrial waste reduction for the formation of a recycling-oriented society, reuse of pole transformers for power distribution has been carried out. In Non-Patent Document 1, as criteria for determining the reuse of transformer windings, (1) presence or absence of abnormalities such as burnout or winding contamination, (2) presence or absence of conduction (disconnection), or quality of insulation resistance, (3) If there are two or more winding repair histories, three items of necessity of rewinding are introduced. A similar test may be performed when a fuse blows due to lightning.

  However, in the above test, it is not possible to detect rare shorts of windings or shorts between turns, which are problematic as abnormalities of pole transformers. In addition, it is desirable that diagnosis of the soundness of the pole transformer can be performed without opening and closing the top cover of the pole transformer in order to reduce labor and to prevent moisture from entering the pole transformer. It is desirable that the work can be carried out in a state of being overlaid on the power distribution column in order to reduce labor and shorten the work time and to prevent the failure due to the removal or re-installation work of the pole transformer from the power distribution column. Note that the layer of the winding wound around the iron core of the transformer is called a layer, and a state where the layers are short-circuited is called a rare short or an interlayer short circuit.

  As a conventional method for determining the presence or absence of a rare short in a distribution pole transformer, for example, an alternating voltage having a different frequency is sequentially applied to the windings of the transformer, and the exciting current of the transformer with respect to the alternating voltage having a different frequency is used. A first-order differentiation is performed on the approximate curve of the measured excitation current value. When the differential value is positive, it is determined that there is no short circuit, and when the differential value is negative, it is determined that there is a short circuit (Patent Document 1). ).

  Further, there is a frequency response analysis (FRA) as a method for diagnosing abnormality of a transformer winding. In frequency response analysis, a sinusoidal electrical signal (eg, voltage) is input and the amplitude of the output signal (eg, current) is measured while changing the frequency from several tens [Hz] to several [MHz]. (For example, impedance) is obtained. The transfer function shows resonance by electrical constants such as leakage inductance, ground capacitance, and interwinding capacitance. If there is an abnormality in the transformer winding, these electrical constants change and the transfer function (specifically, For example, the resonance frequency) changes. In the frequency response analysis, the abnormality of the transformer winding is diagnosed by the presence or absence of the change compared with the transfer function measured when the transformer is in a healthy state.

JP2009-14528

IEEJ Technical Report No. 1164: Trends and Issues in Life Cycle Management of Distribution Equipment, 2009

  However, the method for determining the presence or absence of rare short in Patent Document 1 requires a device for measuring current by sweeping the frequency over a wide range of 300 to 2000 [Hz] and at several hundred points (hundreds of frequencies). There is a problem that measurement is required and cost and much labor and time are required. In particular, since a large number of distribution pole transformers are installed, the rare short presence determination method of Patent Document 1 cannot be said to be highly versatile when targeting distribution pole transformers.

  Further, the frequency response analysis also needs to be performed by changing the frequency from several tens [Hz] to several [MHz], which is costly and takes much time and effort. In fact, frequency response analysis is applied exclusively to transformers larger than the distribution / transformation class, and there is no application example to distribution pole transformers with a very large number of installations.

  Therefore, the present invention can be carried out without opening and closing the top cover of the transformer and using only a general-purpose device, while being kept on the power distribution pole, and can be carried out in a short time with less trouble. It is an object of the present invention to provide a transformer health diagnosis method, a health diagnosis device, and a health diagnosis program that can determine the presence or absence of a fault.

  The present inventor examines a method for evaluating the soundness of a transformer that can be carried out without opening and closing the upper lid of the transformer and using only a general-purpose device while still being wired on a power distribution pole. It was found that the presence or absence of abnormality in the winding of the transformer can be determined by measuring the inductance of the impedance of only one frequency of the pole transformer. A test for verifying the validity of this technical idea unique to the present invention (hereinafter referred to as a verification test) will be described below.

  First, the example of the installation state of the pole transformer which can be made into a diagnostic object by this invention is shown in FIG. Cutout 4 is usually installed on the primary winding side (high voltage side) of the pole transformer 1 wired on the distribution pole, and it is easy and laborious to open the primary winding. Can do without. In addition, the code | symbol 2 in a figure is a distribution transformer inductance.

  On the other hand, the secondary winding side (low voltage side) is directly connected to the customer (load) 3, and a great deal of labor is required to disconnect it. For this reason, in the present invention, the soundness of the transformer is diagnosed while the secondary winding remains connected to the load 3.

  However, since the load 3 is connected to the secondary winding side, it is difficult to make a diagnosis by performing some measurement from the secondary winding side. Therefore, in the present invention, impedance is measured from the primary winding side. At this time, since the connection state of the load 3 is actually various, in order to make the state of the load on the secondary winding side constant, the secondary winding side is short-circuited for measurement. It should be noted that there is no difficulty in operation in terms of short-circuiting the secondary winding side in view of the structure of the transformer.

Moreover, the example of the coil | winding structure of the pole transformer which can be made into a diagnostic object by this invention is shown in FIG. In this pole transformer, 24 rare coils of the primary winding 6A are wound on each of the left and right sides of the iron core 8 in a total of 24 sheets, and the rare of the secondary winding 6B is two on the left and right sides of the iron core 8. There are 4 rolls together. _Reference numeral 7 in the figure represents a tapping board, and reference signs H ⁺ , H _L2,3 ^{+ to} H _L10,11 ⁺ , H ⁻ , H _L2,3 ^{− to} H _L10,11 ⁻ represent each rare terminal. Symbols H _L12 ⁺ and H _L12 ⁻ represent primary terminals (also referred to as high voltage bushings) as transformers, and symbols L ⁺ and L ⁻ represent secondary terminals (also referred to as low voltage bushings) as transformers. Symbol O represents a ground terminal.

In the verification test, nothing is connected between the primary windings 6A (that is, between the primary side terminals H _L12 ⁺ and H _L12 ⁻ ), that is, the primary winding 6A is opened and the secondary winding inter 6B (i.e., secondary-side terminals L ⁺ and L ^- between) measuring the impedance in a state in which short-circuited.

And, for example, like the transformer shown in FIG. 4, each rare of the primary winding 6A of the transformer has terminals (H ⁺ , H _L2,3 ^{+ to} H _L10,11 ⁺ , H ⁻ , H _L2,3 ^{− to} H _L10,11 ⁻ ) are provided, and a short circuit can be simulated by short-circuiting two adjacent rare terminals. Therefore, impedance measurement is performed when each rare terminal of the primary winding 6A is not short-circuited and when short-circuited. Note that the measurement frequency is 110 [Hz] (note that this measurement frequency 110 [Hz] is only the measurement frequency used in the verification test, and the measurement frequency in the present invention is not limited to this).

Each rare terminal (H ⁺ , H _L2,3 ^{+ to} H _L10,11 ⁺ , H ⁻ , H _L2,3 ^{− to} H _L10,11 ⁻ corresponding to the state where the transformer is normal ) And the inductance value of the impedance obtained by the respective measurements and the inductance when the respective rare terminals of the primary winding 6A corresponding to the state where the rare short occurs are short-circuited. Table 1 shows the minute values. Table 1 also shows the short-circuit impedance measurement results in the factory shipment test for the transformer.

  From Table 1, in the normal state, the impedance resistance is greatly different between the measured value and the factory test value due to the influence of the measurement temperature, while the impedance inductance is substantially the same between the measured value and the factory test value. That is confirmed. From this, it is found that factory test data can be used as normal state data when the inductance of the impedance is used as an index for diagnosis of winding abnormality such as rare short.

  In addition, it is known that the transfer functions are the same for transformers of the same design in the frequency response analysis, so it is not necessary to grasp the factory test data for each individual transformer. Specifically, the initial value (factory test data) may be investigated and stored as a database for each rated capacity and design change age.

  Further, from Table 1, when comparing the inductance inductance in the normal state and the rare short state, it is confirmed that the rare short state is slightly smaller than the normal state by 6%. From this, it is found that it is possible to determine whether or not a rare short has occurred by verifying the inductance of the impedance at the time of diagnosis (that is, comparing with the initial value (factory test value)).

  In addition, in the verification test, since a short circuit is simulated by short-circuiting two adjacent rare terminals, it can be said that the state where the two adjacent rares are short-circuited is simulated. In an actual transformer, it is assumed that a rare short that is smaller than this, for example, a rare short occurs at an intermediate point between two adjacent rares. However, the amount of inductance change when a rare short occurs only at the midpoint between two adjacent rares assumed in such an actual transformer is, for example, half (that is, about 3%) of the verification test. However, considering that the measurement accuracy of the LCR meter generally used in actual work is about ± 0.5%, even if the estimation accuracy of the initial value (factory test value) is further considered, It can be said that it is sufficiently possible to detect rare shorts in transformers. Furthermore, since it is considered that rare shorts are basically caused by electric discharge, it is more likely to occur as the potential difference between adjacent windings increases. Therefore, it is considered that rare shorts with small inductance changes rarely occur. It can be said that it is sufficiently possible to detect rare shorts in an actual transformer with the contents confirmed in (1).

  In addition, since it is considered that the impedance inductance changes as well as in the verification test due to a short circuit between turns of the transformer winding, abnormalities in the transformer that can be determined by the transformer health diagnosis method of the present invention, In addition to rare shorts, shorts between turns of windings are included.

  From the results of the above verification test, transformer winding abnormalities (rare short, short between turns) based on the inductance of the impedance measured in the pole transformer (in other words, leakage inductance seen from the primary winding) ), And the presence or absence of the transformer is determined by measuring the inductance of the impedance of the pole transformer at a certain frequency. The validity of the technical idea is confirmed. Although this verification test targets distribution pole transformers, the knowledge gained from this verification test is that it is possible to determine the occurrence of abnormalities such as rare shorts in transformers. The technical idea is also valid for other types of transformers.

  The present invention is based on the above-described knowledge. Specifically, the transformer health diagnosis method according to claim 1 opens the primary winding of the transformer and connects the secondary winding to the load. In this state, the leakage inductance viewed from the primary winding is measured while shorting the secondary windings, and the presence or absence of abnormality in the primary winding is determined based on the inductance value. The soundness of the transformer is determined.

  The transformer health diagnosis device according to claim 2 opens the primary winding of the transformer and short-circuits the secondary windings while the secondary winding remains connected to the load. Means for reading a leakage inductance value as seen from the primary winding measured from the storage device, and determining the presence or absence of abnormality in the primary winding based on the inductance value, and the soundness of the transformer And means for judging.

  The transformer health diagnosis program according to claim 3 opens the primary winding of the transformer and short-circuits between the secondary windings while the secondary winding remains connected to the load. Means for reading from the storage device the value of the leakage inductance as measured from the primary winding, and determining the presence or absence of abnormality in the primary winding based on the inductance value to determine the soundness of the transformer The computer is made to function as a determination means.

  Therefore, according to the soundness diagnosis method, soundness diagnosis device, and soundness diagnosis program for these transformers, the transformer is based on the inductance value of the impedance measured from the primary winding side at a certain arbitrary frequency. Since it is determined whether or not there is an abnormality in the winding (specifically, a short-circuit or short-to-turn short-circuit), there is no need to sweep the frequency over a certain range, The presence or absence of abnormality in the winding of the transformer is determined without opening and closing the top cover.

  Further, according to the soundness diagnosis method, soundness diagnosis device, and soundness diagnosis program for these transformers, the transformer secondary winding remains connected to the load, and the impedance inductance component from the primary winding side is maintained. Therefore, whether or not there is an abnormality in the winding of the transformer is determined in a state where the transformer is kept on the distribution pole.

  According to the transformer soundness diagnosis method, soundness diagnosis apparatus, and soundness diagnosis program of the present invention, it is determined whether or not there is an abnormality in the winding of the transformer without taking the trouble of sweeping the frequency over a certain range. Therefore, it is possible to improve the versatility of the soundness diagnosis technology by reducing the time and measuring time by reducing the labor and time by using only a general-purpose device such as an LCR meter. become. In the case of performing measurement by sweeping the frequency in the low frequency band, the measurement time is generally long. However, according to the present invention, this is not necessary, so that the measurement time can be greatly reduced as compared with the conventional method. It becomes possible.

  Further, according to the soundness diagnosis method, soundness diagnosis device, and soundness diagnosis program of the transformer of the present invention, particularly in the soundness diagnosis of the pole transformer, the state in which the transformer remains overhead on the distribution pole This makes it possible to determine whether there are any abnormalities in the windings of the transformer, thus reducing labor and preventing the occurrence of failures due to the removal or re-installation work of the pole transformer from the distribution pole in a short time. It becomes possible to improve versatility as a soundness diagnosis technique.

  Further, according to the transformer diagnostic method, the diagnostic apparatus, and the diagnostic program of the present invention, it is possible to determine whether there is an abnormality in the winding of the transformer without opening and closing the upper cover of the transformer. Therefore, by diagnosing the soundness, it is possible to avoid the loss of the soundness of the pole transformer and improve the versatility. In particular, the installation location of the pole transformer is usually outdoors, but according to the present invention, the upper lid is not opened and closed, so there is no need to pay attention to the maintenance of the internal state of the pole transformer, and the field applicability is greatly increased. It becomes possible to improve.

It is a flowchart explaining an example of embodiment of the soundness diagnostic method of the transformer of this invention. It is a functional block diagram of the transformer health diagnostic apparatus realized by the said program in the case of implementing the transformer health diagnostic method of embodiment using the transformer health diagnostic program. It is a figure explaining an example of the installation state of the pole transformer which this invention can make into a diagnostic object. It is a figure explaining an example of the coil | winding structure of the pole transformer which this invention can make into a diagnostic object.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.

  1 and 2 show an example of embodiments of a transformer health diagnosis method, a health diagnosis device, and a health diagnosis program according to the present invention.

  As shown in FIG. 1, the transformer health diagnosis method according to the present embodiment opens the primary winding of the transformer and keeps the secondary winding connected to the load. The leakage inductance viewed from the primary winding (in other words, the inductance of the primary winding impedance) is measured while short-circuiting between them (S1), and the presence or absence of abnormality in the primary winding is determined based on the inductance value. Judgment is made to determine the soundness of the transformer (S2).

  In addition, the transformer health diagnosis apparatus of the present embodiment opens the primary winding of the transformer and short-circuits the secondary windings while the secondary winding remains connected to the load. Means (11a) for reading from the storage device the value of the leakage inductance as viewed from the measured primary winding (in other words, the inductance of the impedance of the primary winding), and the abnormality of the primary winding based on the inductance value And means (11b) for determining the soundness of the transformer by determining the presence or absence of the transformer.

  Furthermore, the transformer health diagnosis program according to the present embodiment opens the primary winding of the transformer and short-circuits the secondary windings while the secondary winding remains connected to the load. Means (11a) for reading from the storage device the value of the leakage inductance as viewed from the measured primary winding (in other words, the inductance of the primary winding impedance), and the abnormality of the primary winding based on the inductance value The computer is made to function as means (11b) for judging the presence or absence of the transformer and judging the soundness of the transformer.

  In executing the transformer soundness diagnosis method, first, the inductance of the transformer impedance is measured (S1). In addition, when there are a plurality of transformers to be diagnosed, the processing of S1 and S2 described later is performed for each transformer to be diagnosed.

  In the present invention, the primary winding of the transformer is opened and the secondary winding remains connected to the load, and the leakage inductance viewed from the primary winding (in other words, the inductance component of the primary winding impedance). ) Is measured.

  In the present invention, the leakage inductance as viewed from the primary winding is measured in a state where the secondary windings (secondary terminals) are short-circuited.

  The impedance inductance (leakage inductance viewed from the primary winding) is measured using, for example, an LCR meter. Note that the measurement frequency at the time of inductance measurement is not limited to a specific frequency, and may be, for example, a commercial frequency (that is, 50 [Hz] or 60 [Hz]), or 100 [Hz] or 110 [Hz]. ], 120 [Hz], etc., that is, in the range of several tens to several hundreds [Hz], they may be appropriately selected and set according to the specifications of the LCR meter used for measurement.

  In the present invention, it is only necessary to measure the inductance of the impedance at a certain one frequency. That is, in the present invention, it is not necessary to perform measurement while sweeping the frequency.

  Next, the soundness of the transformer is determined using the inductance value data obtained by the process of S1 (S2).

  Here, the process of S2 in the transformer health diagnostic method of the present invention can be executed by the transformer health diagnostic apparatus of the present invention.

  And the process of S2 in the soundness diagnostic method of a transformer, and the soundness diagnostic apparatus of the transformer which performs the said process can be implement | achieved also by running the soundness diagnostic program of the transformer of this invention on a computer. . In the present specification, a transformer health diagnostic apparatus that executes the process of S2 by executing a transformer health diagnostic program on a computer is realized, and the process of S2 in the transformer health diagnostic method is performed. The case where it is executed will be described.

  FIG. 2 shows an overall configuration of a computer 10 (which is also a transformer health diagnostic apparatus 10 in the present embodiment) for executing the transformer health diagnostic program 17. The computer 10 (transformer soundness diagnostic apparatus 10) includes a control unit 11, a storage unit 12, an input unit 13, a display unit 14, and a memory 15, and is connected to each other by a signal line such as a bus. Further, a data server 16 as a storage device is connected to the computer 10 via a signal line such as a bus, and signals such as data and control commands are transmitted and received (that is, input / output) through the signal line. .

  The control unit 11 performs operations related to the overall control of the computer 10 and the diagnosis of the soundness of the transformer by the transformer soundness diagnosis program 17 stored in the storage unit 12, and for example, a CPU (Central Processing Unit) ).

  The storage unit 12 is a device that can store at least data and programs, and is, for example, a hard disk.

  The memory 15 serves as a memory space that is a work area when the control unit 11 executes various controls and operations, and is a RAM (Random Access Memory), for example.

  The input unit 13 is an interface for giving at least an operator's command to the control unit 11, and is, for example, a keyboard.

  The display unit 14 performs drawing / display of characters, graphics, and the like under the control of the control unit 11 and is, for example, a display.

  In this embodiment, the value of the inductance of the impedance (leakage inductance viewed from the primary winding) at a certain one frequency measured and acquired in the above-described processing of S1 is used as the inductance value database 18 as a data server. 16 is stored (saved). When there are a plurality of transformers to be diagnosed, the inductance value data is recorded in association with an identifier for each transformer.

  In the present embodiment, the value of the impedance inductance (leakage inductance viewed from the primary winding) when the transformer to be diagnosed is in a healthy state is stored (saved) in advance in the data server 16 as the healthy state database 19. Is done. When the transformer to be diagnosed covers a plurality of designs / types / models, the inductance value when the design / type / model is in a sound state is recorded in the sound state database 19.

  Then, the control unit 11 of the computer 10 (which is also the transformer health diagnostic device 10 in this embodiment) executes the transformer health diagnostic program 17 to execute the transformer 1 in the process of S1. The value of the leakage inductance as seen from the primary winding measured while the secondary winding is short-circuited with the secondary winding being connected to the load while the secondary winding is opened as data as a storage device A data reading unit 11a that performs a process of reading from the server 16 and a soundness determination unit 11b that performs a process of determining the soundness of the transformer by determining whether or not the primary winding is abnormal based on the inductance value are configured. The

  And the data reading part 11a comprised by the control part 11 of the computer 10 (transformer soundness diagnostic apparatus 10) by the transformer soundness diagnosis program 17 being executed is the inductance value data as the measured value and the sound state. Reading of inductance value data at.

  Specifically, the data reading unit 11 a reads from the data server 16 the inductance value data measured and acquired in the process of S 1 and recorded in the inductance value database 18 stored in the data server 16. Then, the data reading unit 11a stores the inductance value data in the memory 15 as measured value data. If there are a plurality of transformers to be diagnosed, the identifier for each transformer associated with the inductance value data is read from the inductance value database 18 and the inductance value data is associated with the identifier and stored in the memory 15. Remember me.

  The data reading unit 11a further outputs inductance value data in a healthy state for a transformer of the same design, the same type, and the same type as the diagnosis target transformer recorded in the healthy state database 19 stored in the data server 16. Read from the data server 16. Then, the data reading unit 11a stores the inductance value data in the memory 15 as reference value data.

  Subsequently, the soundness determination unit 11b determines the soundness of the transformer.

  Specifically, the soundness determination unit 11b includes the inductance value data (measurement value data) of the diagnosis target transformer stored in the memory 15 by the data reading unit 11a and the inductance value data (reference value data) in a healthy state. Are read from the memory 15 and the inductance value as the measurement value data is compared with the inductance value as the reference value data.

  If the difference between these inductance values does not exceed the difference determined by the soundness determination threshold, it is determined that no abnormality has occurred in the winding and the soundness of the transformer is maintained, and soundness determination is made. If the difference determined by the threshold is exceeded, it is determined that a winding abnormality (rare short, short between turns) has occurred and the soundness of the transformer is impaired.

  Here, the soundness determination threshold value is a threshold value for determining that a winding abnormality (rare short, turn-to-turn short-circuit) occurs and the soundness of the transformer is impaired, and the inductance in the sound state It is set as a value representing the difference between the value Lo and the inductance value Lw in a state such as rare short. Specifically, a difference percentage between two values (that is, (Lo−Lw) / Lo × 100 [%]) or a difference between two values (that is, Lo−Lw [mH]) may be set. Conceivable. The soundness determination threshold value is defined in advance in, for example, the soundness diagnosis program 17 of the transformer.

  The value of the soundness determination threshold value is not limited to a specific value, and is appropriately set based on, for example, actual results up to that point. Specifically, for example, it is conceivable to set the difference percentage to about 1 to 5%, or to set the difference to about 3 to 10 mH. In addition, when the soundness judgment threshold value is uniquely determined, the impedance inductance value in the state of simulating the rare short of the primary winding and the impedance inductance amount in the healthy state as in the verification test described above. It is conceivable to set based on the difference from the value.

  And the soundness determination part 11b displays that the soundness of the transformer is maintained or impaired as a determination result by the process of S2, for each transformer to be diagnosed, if necessary. The data is displayed on the unit 14 or stored as a diagnosis result data file in the storage unit 12 or the data server 16, for example.

  And the control part 11 complete | finishes the process of the soundness diagnosis of a transformer (END).

  According to the soundness diagnosis method, soundness diagnosis apparatus, and soundness diagnosis program of the transformer of the present invention having the above-described configuration, the transformer winding can be performed without taking the trouble of sweeping the frequency over a certain range. Since it is possible to determine the presence or absence of abnormality, for example, only a general-purpose device such as an LCR meter is sufficient for diagnosing the soundness of the transformer, while reducing labor and shortening the measurement time, thereby improving the versatility as a soundness diagnosis technique. Can be achieved. In addition, especially in the health diagnosis of pole transformers, it is possible to determine whether there are any abnormalities in the windings of the transformer while the transformer is still on the distribution pole. In addition, it is possible to improve the versatility as a soundness diagnosis technique by preventing the occurrence of failure due to the removal of the pole transformer from the distribution pole and the re-installation work. Also, since it is possible to determine the presence or absence of abnormality in the transformer winding without opening and closing the top cover of the transformer, it is possible to avoid damaging the soundness of the pole transformer by diagnosing soundness. Therefore, it becomes possible to improve versatility.

  In addition, although the above-mentioned form is an example of the suitable form of this invention, it is not limited to this, A various deformation | transformation implementation is possible in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment, the storage means for storing the inductance value data (measurement value data, reference value data) of the transformer is used as the data server 16, but the storage unit 12 may be used or another storage device may be used. Anyway.

  Further, the present invention is not limited to the distribution pole transformer, and can be applied to various transformers having two windings and capable of opening one winding and short-circuiting the other winding. It is.

10 Transformer health diagnostic device 17 Transformer health diagnostic program

Claims (3)

  With the primary winding of the transformer open and the secondary winding connected to the load, the leakage inductance viewed from the primary winding is measured while shorting the secondary windings, A transformer health diagnosis method, wherein the transformer health is judged by judging whether or not the primary winding is abnormal based on an inductance value.   Leakage inductance value measured from the primary winding measured while shorting between the secondary windings while the primary winding of the transformer is opened and the secondary winding remains connected to the load And a means for judging the soundness of the transformer by judging the presence or absence of abnormality of the primary winding based on the value of the inductance. Sex diagnostic device.   Leakage inductance value measured from the primary winding measured while shorting between the secondary windings while the primary winding of the transformer is opened and the secondary winding remains connected to the load Of the transformer, wherein the computer functions as means for judging whether or not the primary winding is abnormal based on the inductance value and judging the soundness of the transformer. Health diagnostic program.

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