JP2019125767A - Transformer deterioration status display device - Google Patents

Abstract

To provide a transformer deterioration status display device that can continuously display a deterioration status of a transformer.SOLUTION: One of degradation gradients in a graph group of polymerization degree degradations with time of a transformer insulation paper is defined as a polymerization degree degradation reference gradient Kc; a temperature of an insulation paper of a transformer to be diagnosed under a reference use condition and in an actual use state is calculated from an insulation-oil temperature or an installation site temperature of the transformer to be diagnosed and operation electric currents of the transformer to be diagnosed, by utilizing an approximation formula of the insulation-oil temperature with respect to load factor of the transformer; a polymerization degree degradation gradient correction coefficient R is calculated based on a formula of R=1/exp(-H×Tzs) from an insulation paper temperature difference Tzs between the insulation paper temperature under the reference use condition and the insulation paper temperature in the actual use state; the calculated polymerization degree degradation gradient correction coefficient R is multiplied by a reference gradient Kc to determine an actual gradient K of the polymerization degree degradation; and a transition of polymerization degrees from the past to the present time, which are degraded by the actual gradient K and a transition of polymerization degrees in the future are displayed on a graph 30.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technique for displaying the deterioration state of a transformer by the decrease in the average degree of polymerization (hereinafter referred to as the degree of polymerization) of insulating paper (hereinafter referred to as insulating paper and abbreviatedly described) attached between transformer windings. .

  It is being promoted to estimate the remaining life based on the degree of polymerization degree reduction of the insulating paper and to update the transformer before the end of the transformer life to prevent an accident due to deterioration.

As a means to investigate the deterioration condition of the insulation paper, a known method of taking out a part of the insulation paper at the time of transformer power failure and measuring the polymerization degree, and methods of the following documents 1 and 2 which estimate the polymerization degree in the operating condition Is taken.
Patent No. 4323396 Patent No. 5387877

  The known method of taking out a part of the insulating paper and measuring the degree of polymerization can only be carried out at the time of periodic inspection, and even if there is a sharp deterioration of the transformer usage conditions after restarting the transformer operation, confirmation until the next periodic inspection As it can not be done, it has missed the sign of an accelerated decline in the degree of polymerization, and has the disadvantage that the accident prevention measures such as improvement of the transformer use conditions will be delayed.

  The method of Patent Document 1 capable of grasping the degree of polymerization even during transformer operation removes the estimated heat history of the insulating paper temperature based on the load history of the diagnosed transformer, the weather information and the insulating oil temperature measured at the time of inspection A method is employed in which the remaining life is determined by bringing it into contact with a master curve indicating the relationship between the heat history and the degree of polymerization of the insulating paper prepared from the measured values of the degree of polymerization of the transformer insulating paper and the like.

  The method of Patent Document 2 which is another method capable of grasping the degree of polymerization even during transformer operation is deterioration of CO, CO 2, furfural, etc. contained in the insulating oil collected at the time of periodic inspection of the diagnosed transformer, etc. A method is used to estimate the degree of polymerization based on the amount of indicator components and the operating environment data such as the operating years of the transformer under test and the load factor to determine the remaining life.

  However, the methods of Patent Document 1 and Patent Document 2 are evaluation methods for a specific transformer for which acquisition of insulation deterioration index data from insulating paper or oil is performed, and for transformers that do not acquire insulation deterioration index data. Inapplicable and because it is an intermittent evaluation method at the time of inspection, it will miss the sign of an accelerated decline in the degree of polymerization when there is a sharp deterioration of the transformer usage condition after the inspection, preventing accident It has the disadvantage that it can not be implemented in a timely manner.

  The present invention has been made in view of the above circumstances, and the degree of polymerization from the start of use of the transformer to the present over the entire transformer including the small-capacity transformer which often does not obtain the insulation deterioration index. By continuously indicating the state of decline, it is possible to monitor the signs of polymerization degree drop due to sudden changes in transformer operating conditions without missing them, and aim to enable timely improvement of transformer operating conditions. Do.

In order to achieve the above object, the device according to claim 1 is a transformer deterioration status display device which indicates the deterioration status of the transformer by the transition of the degree of polymerization, and the transformer has a degree of polymerization reduction reference gradient Kc. Insulating paper temperature at the standard use conditions (installation location reference temperature Tac (one of 6 to 18 ° C.), reference operation load factor Uc (one of 10 to 70%)) as the insulation paper reference temperature Tzc, The gradient of the degree of polymerization when it is continuously operated under the standard use conditions is from the degree of polymerization at the start of use of the transformer (one of 800 to 1000) and any one of 10 / year to 60 / year The gradient of the degree of polymerization decrease straight down is the slope of the degree of polymerization decrease reference gradient Kc, and in the diagnostic transformer whose operating state changes, the degree of polymerization decrease gradient correction factor R (hereinafter referred to as the slope below) The correction factor R) It is assumed that the polymerization degree decreases the actual gradient K multiplied by the degree lowering reference gradient Kc, and the gradient correction coefficient R is the difference between the insulating paper temperature Tz at the time of operation and the insulating paper reference temperature Tzc at the reference conditions. Formula R = 1 / exp (−H × Tzs) ··· (Equation 1) relating to the insulating paper temperature difference Tzs
(Here, H is one of 0.06 to 0.14 (1 / ° C.))
Means for calculating by
Data acquisition of either the first data acquisition means for acquiring the insulating oil temperature To of the diagnostic transformer, the second data means for acquiring the installation temperature Ta of the diagnosis transformer, and the operating current I, or both Means,
Approximate expression To ≒ Ta + Tm + ^Ux × (A−Tm) ········· (Equation 2)
(Here, Ta is the temperature at the transformer installation site, Tm is the temperature rise value of the insulating oil at no load, A is the temperature rise value of the insulating oil at rated operation)
Means for calculating by
Insulating paper temperature Tz, the approximate equation ^{Tz ≒ Ta + Tm + U y} × (A + Tp-Tm) of the insulating sheet temperature Tz about load ratio U plus temperature difference between the insulating sheet and the insulating oil in (Equation 1) ..... (Equation 3)
(Here, Ta is the temperature at the transformer installation site, Tp is the temperature difference between the insulation paper and the insulation oil during rated operation)
Means for calculating by
In the one having the first data acquisition means,
Approximate expression U に^関す^る ((To-Ta-Tm) / (A-Tm)) related to the acquisition temperature To of the load factor U obtained from the above (formula 2) ^{(1 / x)} ... (formula 4)
Calculates the virtual load factor U that brings the obtained insulating oil temperature To, and substitutes the calculated virtual load factor U into the above (Equation 3) to obtain the insulating paper temperature Tz when the obtained insulating oil temperature is To First insulating paper temperature calculating means to calculate;
Second insulating paper temperature calculating means for calculating the insulating paper temperature Tz by substituting the load factor U obtained by dividing the obtained operating current by the rated current into the above (Equation 3) in the one having the second data acquiring means Either or both of the insulating paper temperature calculation means,
The insulation paper temperature difference Tzs is calculated as the difference between the insulation paper temperature Tz calculated by either the first or second insulation paper temperature calculation means and the insulation paper reference temperature Tzc, and the calculated insulation paper temperature difference Tzs is calculated. A means for calculating the gradient correction coefficient R by substituting in the equation (1) and multiplying the reference gradient Kc by the calculated gradient correction coefficient R to calculate the actual gradient K of the gradient decrease; Means of storing the polymerization degree by time of polymerization degree by time and the polymerization degree by date in the polymerization degree storage unit, and as an average value of a plurality of polymerization degree reduction gradients used for calculation of a plurality of polymerization degrees before the current time Calculation condition according to the above-mentioned degree of polymerization decrease gradient calculation means by means for calculating the future degree of polymerization degree decrease prediction gradient and the calculation condition (input temperature of installation place temperature and calculation load factor of transformer) inputted from the input section Future polymerization degree in A means for calculating the lower slope, transition of the degree of polymerization from the start of use of the diagnostic transformer read from the degree of polymerization storage unit to the present time, and polymerization along the gradient expected to decrease the degree of polymerization after the present time A means for displaying the predicted transition of the degree of polymerization and the transition of the degree of polymerization after the current time along the gradient of the degree of polymerization decrease calculation on a long-term polymerization degree transition graph from several years after the start of use of the diagnosed transformer It is characterized by comprising means for simultaneously displaying or alternately displaying a degree transition graph and a short-term polymerization degree transition graph around several days starting from the present time.

  According to the method of the present invention, the polymerization degree is accelerated due to the sharp deterioration of the use condition by continuously showing the degree of deterioration of the degree of polymerization from the start of use of the transformer to the present, over all the transformers used in Japan. It becomes possible to constantly evaluate the degree of polymerization degree decline and the transformer operation condition without missing the dynamic deterioration situation, improve the transformer operation condition in a timely manner, and prevent the occurrence of the accident caused by the transformer deterioration. it can.

  It is a graph which shows the reference | standard gradient of polymerization degree fall in this invention.   It is a graph which shows the temperature of the transformer insulation oil and insulation paper with respect to the load factor by this invention.   It is an example of the long-term short-term polymerization degree transition composite display graph of the transformer degradation display apparatus by this invention.   It is a block diagram which shows the structure of the transformer degradation display apparatus by the Example of this invention.   FIG. 5 is a flow diagram illustrating the processing of the transformer degradation indicator according to an embodiment of the present invention.   It is a graph which shows the relationship of the operating age and average polymerization degree as described in JEM1463.   It is a graph which shows the relationship of the operating age and polymerization degree as described in transformer maker technical data description.   It is a survey list classified by type of transformer load factor published by the Japan Electric Industry Association.   It is an example of the temperature rise graph of the insulating oil with respect to the load factor described in Unexamined-Japanese-Patent No. 2001-291626, and an insulating paper.

  Hereinafter, the best mode for carrying out the transformer selection according to the present invention will be described in detail according to the attached drawings.

  FIG. 1 shows an example of the polymerization degree reduction reference gradient according to the present invention based on FIGS. 6 and 7 published in Japan as a time-dependent decrease transition graph of the degree of polymerization of transformer insulating paper. The straight line 1a is taken as the straight line on the upper limit side of the degree of polymerization in FIG. 7 showing the minimum slope in the transition graph of degree of polymerization decrease (the degree of polymerization at the start of operation is 900, the decrease slope is 12.5 / year), The straight line 1b is taken as the straight line on the lower limit side of the degree of polymerization in FIG. 8 showing the maximum slope among the decline degree graphs of degree of polymerization (the degree of polymerization at the start of operation is 900 and the decline slope is 50 / year) An intermediate straight line 1c between the straight line 1a and the maximum gradient straight line 1b is an intermediate gradient (the polymerization degree at the start of operation is 900, and the decreasing gradient is the reference gradient K (25 / year)), any of the above 1a, 1b, 1c It is assumed that the degree of polymerization reduction reference gradient Kc.

  The standard slope Kc of the transformer installation location reference temperature Tac is shown in Figure 1 from 8 ° C in the Hokkaido area, 16 ° C in the Kyushu area, and 12 ° C in both areas on average annual temperature in the past 40 years according to JMA published data. When the installation location reference temperature Tac is 8 ° C., and the reference gradient Kc is 1 c in FIG. 1, the reference temperature Tac of the transformer installation location is 12 ° C., and the reference gradient Kc is 1 b in FIG. The reference temperature Tac of the transformer installation place is 16 ° C.

  The transformer operation reference load factor Uc is an average load factor 37 when the distribution of the load factor of 290 cases described as one day in the industrial load list of the transformer load factor shown in FIG. 8 is a normal distribution. The reference gradient Kc is defined as 1a in FIG. 1 from the lowest load factor of 19.5% and the maximum load factor of 55.2%, which is calculated with an average value ± 2σ from 3% and standard deviation value σ = 8.93%. When the reference load factor Uc in the case is 19.5% and the reference gradient Kc is 1c in FIG. 1, the reference load factor Uc is 37.3%, and the reference load Kc is 1b in FIG. Is applied as 55.2%.

  The insulation paper reference temperature Tzc is the average of the insulation oil temperature when the maximum load factor is applied to (Equation 3) based on the installation location reference temperature Tac and the insulation oil temperature when the minimum load factor is applied. The value is applied.

FIG. 2 is an approximate characteristic diagram of the insulating oil temperature To and the insulating paper temperature Tz with respect to the load factor U according to the present invention, in (Equation 2) and (Equation 3) The paper temperature rise value Tm is 6 ° C, the insulation oil temperature rise value A at rated operation is 30 ° C, x is squared, y is 1.8 raised, and the temperature difference Tp between the insulating water and the insulating paper at rated operation is 15 ° C,
To 12 12 + 6 + U ² × (30-6) ... (Equation 5)
Tz 12 12 + 6 + U ^1.8 × (30 + 15-56) ... (6)
Shows an example that approximates the published test data (FIG. 9).

H in the above (formula 1), which is a calculation formula of the gradient correction factor R, is due to Arrhenius's half-law relating to thermal degradation of the insulator, and the 8 ° C. half-law is considered to be highly compatible with Class A insulating materials R = 1 / exp (-0.8664 x Tzs) which adopted H = 0.08664 in the case of ... (Equation 7)
Is applied.

  Acquisition of the temperature Ta of the transformer installation place in the second data acquisition means is based on a method of measuring the temperature near the installation place or adding the difference between the air temperature and the installation place temperature to the Meteorological Agency air temperature data of the installation area.

FIG. 3 is an example of a composite display graph in which the long-term display graph 30 of the transformer deterioration state according to the present invention and the short-term display graph 31 are overlapped, and the solid line 21 represents the polymerization from the start of use of the diagnosed transformer to the present time Shows the transition of the degree, the hourly polymerization degree Jh ₂ of the current time,
Jh ₂ = Jh ₁ −Δh (Equation 8)
(However, Jh ₁ is the hourly polymerization degree one hour before the current time, and Δh is the polymerization degree decrease from one hour before the present time shown in (Expression 9) described later)
Δh = Kcj × R... (Equation 9)
(However, Kcj is a reference gradient per hour shown in (Expression 10) described later)
Kcj = 25/8760 = 0.002854 (Equation 10)
It shows by the process by the representative polymerization degree (for example, the final value every 10 days, the monthly final value, etc.) based on the degree of polymerization by date which is the daily final value of the degree of polymerization calculated by

  The gradient Ky of the broken line 22 indicating the transition of the degree of polymerization decrease expected transition after the current time in FIG. 3 is an average value of a plurality of gradients on the day and several days before.

  The gradient Kt of the dashed-two dotted line 23 indicating the polymerization degree decrease trial calculation gradient after the current time in FIG. 3 is calculated by the means after the above-mentioned second insulating paper temperature calculation means.

  The number of years until the degree of polymerization decreased by the predicted gradient Ky and the estimated gradient Kt reaches the life judgment value is the current degree of polymerization and the estimated lifetime polymerization degree when the estimated gradient Ky and the estimated gradient Kt are the gradients per year. Divided by the predicted slope Ky or the estimated slope Kt.

  When the degradation display is performed during the operation of the transformer already in operation, if there is an insulation oil temperature history from the start of operation to the current time, the insulation paper temperature Tz is sequentially calculated by the first insulation paper temperature calculation means If there is no insulating oil temperature history, calculate the degree of polymerization according to the current time by the second insulating paper temperature calculation means from the installation place temperature history and the operation load factor history, and then figure It enters into the processing process flow after the storage to the time-dependent polymerization degree memory | storage part in 5, and the following time-dependent polymerization degree calculation.

  Regarding the transformer to be diagnosed, the degree of polymerization according to another life diagnosis method or the degree of over-currenting is reviewed and the degree of polymerization is shown. If the value is judged appropriate, the degree of polymerization according to the present date After that, the processing flow from the storage to the time-based polymerization degree storage unit in FIG. 5 and the subsequent time-based polymerization degree calculation is entered.

  FIG. 4 is a block diagram showing the configuration of a transformer deterioration status display device according to an embodiment of the present invention, including a data collection unit 51 for collecting transformer insulating oil temperature, a polymerization degree calculation unit 52a, and calculation of future polymerization degree A calculation processing unit 52 having a unit 52b and a remaining life calculation unit 52c, a polymerization degree storage unit 53, a graph creation processing unit 54 for generating a polymerization degree history graph, a display unit 55 for displaying a polymerization degree history graph, The control unit 57 includes a setting unit 56 for giving a rated current of the diagnostic transformer, a calculation condition, and the like, and a control unit 57 for giving a date and time.

  FIG. 5 is a flow chart showing the process of the transformer deterioration state display device according to the present invention, wherein the data acquisition unit 51 for acquiring the insulating oil temperature, operating current, etc. of the diagnosed transformer is divided by time based on collected data. From the storage unit 53 which stores the calculated degree of polymerization for each time by the time via the polymerization degree calculation unit 52a for calculating the degree of polymerization or the degree of polymerization for each day, calculation of the degree of polymerization for the future from the storage portion 53 The transfer of a plurality of time-based polymerization degrees and a plurality of date-based polymerization degrees to the part 52b, the processing flow up to the display part 55 through the polymerization degree transition graph creation processing part 54 and the like are shown.

  FIG. 6 is a graph showing the relationship between the number of years of operation and the average degree of polymerization described in JEM 1463-1993 “Average polymerization degree evaluation criteria for insulating paper for transformers”, and among the data group envelopes shown in the graph The solid line on the side where the degree of polymerization is high corresponds to the process of the degree of polymerization under the best use conditions in the present invention.

  FIG. 7 is a graph showing the relationship between the number of operating years and the degree of polymerization described in the manufacturer's technical data (January 1997, Hitachi Technical Note, Transformer edition “Aging Deterioration of Oil-filled Transformer”). Of the lines shown, the straight line with the largest slope corresponds to the degree of polymerization under the worst use conditions in the present invention.

  Fig. 8 is a table of transformer load factor by type of industry (April 2002, Japan Electric Industry Association, Comprehensive Energy Research Association, transformer judgment criteria subcommittee survey results) published in Japan. The loading factor 290 data described therein as per day is quoted in the loading factor range for calculating the degree of polymerization in the present invention.

  FIG. 9 is an example of published data on the temperature rise of the insulating oil and the winding with respect to the use load factor of the transformer, and is an example of the graph shown in JP-A 2001-291626 and FIG.

A · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Temperature of insulating oil at rated operation Ta · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Difference Tat ... Transformer installation place temperature for trial calculation To ... Insulating oil temperature Tz at the time of operation ... Insulating paper temperature Tzc at the time of operation ... Insulating paper reference temperature Tzs at the standard use condition ... At the time of operation Insulating paper temperature difference between the insulating paper temperature and the insulating paper reference temperature Tzst: Insulating paper temperature difference between the insulating paper temperature and the reference insulating paper temperature under the calculation condition I: operating current U · · · of the diagnostic transformer Load factor Uc: Standard load factor Ut: Load factor for trial calculation K: Degree of polymerization reduction actual slope Kc: Degree of polymerization reduction reference slope Kcj: Degree of polymerization reduction standard slope Ky: per hour・ ・ ・ Deterioration degree of polymerization degree decrease gradient Kt ・ ・ ・ Estimation degree decrease degree of polymerization degree R ・ ・ ・Correction coefficient _Jh 2 · · · the current time of the polymerization degree _Jh 1 · · · decreased polymerization degree 1a · · · minimum slope degree of polymerization of 1 hour before the current time linear 1b · · · maximum slope polymerization degree decreases linearly 1c · · · Standard gradient degree of polymerization decrease straight line 21 ····································· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · expected to have a degree of polymerization. Long-term display graph 31 of transformer deterioration status ... Short-term display graph 50 of transformer deterioration status ... Transformer deterioration status display device 51 ... data acquisition unit 52 ... operation processing unit,
52a ... polymerization degree calculation unit 52c ... remaining life operation unit 52b ... future part polymerization degree calculation unit 53 ... storage unit 54 ... graph creation processing unit 55 ... display unit 56 ... Setting unit 57 ··· Control unit

In order to achieve the above object, the device according to claim 1 is a transformer deterioration status display device which indicates the deterioration status of the transformer by the transition of the degree of polymerization, and the transformer has a degree of polymerization reduction reference gradient Kc. Insulating paper temperature at the standard use conditions (installation location reference temperature Tac (one of 6 to 18 ° C.), reference operation load factor Uc (one of 10 to 70%)) as the insulation paper reference temperature Tzc, The gradient of the degree of polymerization when it is continuously operated under the standard use conditions is from the degree of polymerization at the start of use of the transformer (one of 800 to 1000) and any one of 10 / year to 60 / year The gradient of the degree of polymerization decrease straight down is the slope of the degree of polymerization decrease reference gradient Kc, and in the diagnostic transformer whose operating state changes, the degree of polymerization decrease gradient correction factor R (hereinafter referred to as the slope below) The correction factor R) It is assumed that the polymerization degree decreases the actual gradient K multiplied by the degree lowering reference gradient Kc, and the gradient correction coefficient R is the difference between the insulating paper temperature Tz at the time of operation and the insulating paper reference temperature Tzc at the reference conditions. Formula R = 1 / exp (−H × Tzs) ··· (Equation 1) relating to the insulating paper temperature difference Tzs
(Here, H is one of 0.06 to 0.14 (1 / ° C.))
Any of the first data acquisition means for acquiring the insulating oil temperature To of the diagnosed transformer, and the second data means for acquiring the installation location temperature Ta of the diagnosed transformer and the operating current I Or both data acquisition means,
In the one having the first data acquisition means,
Approximate expression To ≒ Ta + Tm + ^Ux × (A−Tm) ········· (Equation 2)
(Where Ta is the temperature at the transformer installation site, Tm is the temperature rise value of the insulating oil at no load, A is the temperature rise value of the insulating oil at rated operation),
Approximate expression ^{Tz ≒ Ta + Tm + U y} × of the 1-a of the insulating sheet temperature Tz about load factor U (A + Tp-Tm) ····· ( Equation 3)
(Here, Tp is the temperature difference between the insulation paper and the insulation oil during rated operation)
EQUATION 2 Calculating formula of virtual load factor Ui which brings about insulating oil temperature To derived from said (Formula 2),
U ^{i (} ((To-Ta-Tm) / (A-Tm)) ^{(1 / x)} (Equation 4)
First-a insulating paper temperature calculation means for calculating the insulating paper temperature Tz at the insulating oil temperature To by substituting the load factor according to
1-b approximation of insulation paper temperature Tz with respect to insulation oil temperature To
Tz ≒ C × To (Equation 4)
(Here, C is a ratio of the insulating paper temperature Tzc according to the above (Equation 3) to the insulating oil temperature Toc according to the above (Equation 2) under the standard use condition)
First-b insulating paper temperature calculating means for calculating the insulating paper temperature Tz at the insulating oil temperature To by
In the one having the second data acquisition means, the second insulation for calculating the insulating paper temperature Tz at the load factor U by substituting the load factor U obtained by dividing the acquired operating current by the rated current into the above (Equation 3) Paper temperature calculation means,
The insulating paper temperature difference Tzs is calculated as the difference between the insulating paper temperature Tz calculated by any of the first to the first insulating paper temperature calculating means and the insulating paper base temperature Tzc under the standard use condition. The gradient correction coefficient R is calculated by substituting the calculated insulating paper temperature difference Tzs into the equation (1) and multiplying the reference gradient Kc by the calculated gradient correction coefficient R to calculate the actual gradient K of the gradient decrease A means for calculating, a means for storing the degree of polymerization by time and the degree of polymerization by date falling due to the actual gradient K in the degree of polymerization storage unit, and a plurality of polymerizations used for calculation of a plurality of degrees of polymerization before the current time Based on the means for calculating the expected degree of polymerization drop in the future after the current time as the average value of the degree of decrease slope, and the trial calculation conditions (temperature of installation place for transformer calculation and load factor for trial calculation) input from the input section According to the polymerization degree decrease gradient calculation means Means for calculating the gradient for lowering the degree of polymerization under the estimated conditions, transition of the degree of polymerization from the start of use of the diagnosed transformer to the current time, read from the degree of polymerization storage, and polymerization for the future after the current time Expected transition of degree of polymerization along the expected decline in degree of polymerization and transition of degree of polymerization after the present time along the estimated slope of decrease in degree of polymerization on a long-term degree of polymerization transition graph from several years after the start of use of the diagnostic transformer A means for displaying or means for simultaneously displaying or alternately displaying the above-mentioned long-term polymerization degree transition graph and a short-term polymerization degree transition graph around several days starting from the present time is provided.

FIG. 1 shows an example of the polymerization degree reduction reference gradient according to the present invention based on FIGS. 6 and 7 published in Japan as a time-dependent decrease transition graph of the degree of polymerization of transformer insulating paper. The straight line 1a is taken as the straight line on the upper limit side of the degree of polymerization in FIG. 7 showing the minimum slope in the transition graph of degree of polymerization decrease (the degree of polymerization at the start of operation is 900, the decrease slope is 12.5 / year), The straight line 1b is taken as the straight line on the lower limit side of the degree of polymerization in FIG. 8 showing the maximum slope among the decline degree graphs of degree of polymerization (the degree of polymerization at the start of operation is 900 and the decline slope is 50 / year) (in operation start time of the polymerization degree is 900, the reference slope K (25 / year decrease slope)) linearly 1a and maximum slope intermediate straight 1c intermediate slope of the line 1b and then, the 1a, 1b, among 1c any one of the slope of the straight line and the degree of polymerization reduction reference slope Kc of There.

The transformer operation reference load factor Uc is an average load factor 37 when the distribution of the load factor of 290 cases described as one day in the industrial load list of the transformer load factor shown in FIG. 8 is a normal distribution. The reference gradient Kc is defined as 1a in FIG. 1 from the lowest load factor of 19.5% and the maximum load factor of 55.2%, which is calculated with an average value ± 2σ from 3% and standard deviation value σ = 8.93%. The reference load factor Uc in the case where the reference load factor Uc is 19.5% and the reference gradient Kc is 1c in FIG. 1 is the insulating oil temperature at the lowest load factor 19.5% and the maximum load factor 55.2. The reference load factor Uc is applied as 55.2% when the virtual load factor according to (Equation 4) and the reference gradient Kc are 1b in FIG.

The insulating paper reference temperature Tzc applies the insulating paper temperature when the installation location reference temperature Tac and the reference load factor Uc are applied to (Equation 3).

FIG. 2 is an approximate characteristic diagram of the insulating oil temperature To and the insulating paper temperature Tz with respect to the load factor U according to the present invention, in (Equation 2) and (Equation 3) The paper temperature rise value Tm is 6 ° C, the insulation oil temperature rise value A at rated operation is 30 ° C, x is squared, y is 1.8 raised, and the temperature difference Tp between the insulating water and the insulating paper at rated operation is 15 ° C,
To 12 12 + 6 + U ² × (30-6) · · · · · (Equation 5)
^{Tz ≒ 12 + 6 + U 1.8} × (30 + 15- 6) ···· ( Formula 6)
Shows an example that approximates the published test data (FIG. 9).

FIG. 3 is an example of a composite display graph in which the long-term display graph 30 of the transformer deterioration state according to the present invention and the short-term display graph 31 are overlapped, and the solid line 21 represents the polymerization from the start of use of the diagnosed transformer to the present time Shows the transition of the degree, the hourly polymerization degree Jh ₂ of the current time,
Jh ₂ = Jh ₁ −Δh (Equation 8)
(However, Jh ₁ is the hourly polymerization degree one hour before the current time, and Δh is the polymerization degree decrease from one hour before the present time shown in (Expression 9) described later)
Δh = Kcj × R (Equation 9)
(However, Kcj is a reference gradient per hour shown in (Expression 10) described later)
Kcj = Kc / 8760 = 0.002854 ... (Equation 10)
It shows by the process by the representative polymerization degree (for example, the final value every 10 days, the monthly final value, etc.) based on the degree of polymerization by date which is the daily final value of the degree of polymerization calculated by

A ... Insulating oil temperature rise value at rated operation
C · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ratio of the temperature of the insulating paper to the temperature of the insulating oil under the standard condition Ta · · · · Temperature difference with insulating oil Tat ・ ・ ・ Estimated transformer installation temperature
Tm ··· Insulating oil temperature rise value without load · · · Insulating oil temperature during operation
Toc ... Insulating oil temperature Tz under standard operating conditions ... Insulating sheet temperature during operation Tzc ... Insulating sheet reference temperature under standard operating conditions Tzs ... Between insulating sheet temperature during operation and insulating sheet reference temperature Insulating paper temperature difference Tzst ··· Insulating paper temperature difference between insulating paper temperature and reference insulating paper temperature under estimated conditions I · · · Operating current U of the transformer to be diagnosed · · · Load factor Uc · · · Reference load factor
Ui ··· Virtual load factor Ut ······ Load factor K for trial calculation ··· Polymerization degree lowering actual slope Kc ··· Polymerization degree lowering reference slope Kcj ··· 1 degree of polymerization lowering reference slope Ky ··· Polymerization Degree drop expected slope Kt ··· Polymerization degree drop trial calculation slope R ··· Gradient correction coefficient Jh ₂ ··· Polymerization degree at current time Jh ₁ ··· Polymerization degree one hour before current time 1 ··· Minimum slope Degree of polymerization decrease straight line 1b ... Maximum gradient degree of polymerization decrease straight line 1 c ... Intermediate gradient degree of polymerization decrease straight line 21 ... Degree of polymerization decrease transition to current time 22 ... Transition of expected polymerization degree decrease after current time 23 ... The degree of polymerization degree decrease transition 30 after the current time under the calculation condition 30 ... Long-term display graph of transformer deterioration status 31 ... Short-term display graph of transformer deterioration status 50 ... Transformer deterioration status display device 51: data acquisition unit 52: arithmetic processing unit
52a ... polymerization degree calculation unit 52c ... remaining life operation unit 52b ... future part polymerization degree calculation unit 53 ... storage unit 54 ... graph creation processing unit 55 ... display unit 56 ... Setting unit 57 ··· Control unit

Claims (1)

It is a degradation status display device of a transformer which shows the degradation status of a transformer by the decline transition of the average degree of polymerization of the insulating paper (hereinafter referred to as the degree of polymerization), Insulating paper temperature at the installation location reference temperature Tac (one of 6 to 18 ° C) and reference operating load factor Uc (one of 10 to 70%) is continuous at the insulating paper reference temperature Tzc and reference use conditions The polymerization that the gradient of the degree of polymerization at the time of operation is lowered from the degree of polymerization at the start of transformer operation (one of 800 to 1000) by any one gradient of 10 / year to 60 / year In the diagnostic transformer whose operating state changes with the gradient of the degree drop straight line as the degree of polymerization drop standard slope Kc, the degree of polymerization drop slope correction factor R (hereinafter referred to as the slope correction factor R) calculated in relation to the operating conditions Said polymerization degree reduction standard gradient It is assumed that the degree of polymerization decreases actual gradient K multiplied by Kc, and the gradient correction coefficient R is the difference between the insulating paper temperature Tz at the time of operation and the insulating paper reference temperature Tzc at the reference condition. Means for calculating according to the formula R = 1 / exp (−H × Tzs), where H is one of 0.06 to 0.14 (1 / ° C.); The first data acquisition means for acquiring the insulating oil temperature To, and the second data means for acquiring the installation location temperature Ta of the diagnostic transformer and the operating current I, or both data acquisition means, and the insulating oil Of the insulation oil temperature To with respect to the load factor U ≒ Ta + Tm + U ^x × (A-Tm), where Ta is the temperature at the transformer installation site and Tm is the temperature of the insulation oil at no load Rising value, A is at the time of rated operation Insulating paper temperature with respect to the load factor U obtained by adding the temperature difference between the insulating oil and the insulating paper to the means for calculating the temperature rise value of the oil and adding the temperature difference between the insulating oil and the insulating paper Tz approximate expression ^{Tz ≒ Ta + Tm + U y} × of (a + Tp-Tm), and means for calculating the (here, the temperature difference Ta transformers installation location of the temperature, Tp the insulating paper at the time of rated operation and the insulating oil), In the one having the first data acquisition means, an approximate expression U に 関 す る ((To-Ta-Tm) / (A-Tm) related to the acquisition temperature To of the load factor U obtained from the approximate expression of the insulating oil temperature To The load factor U that yields the obtained insulating oil temperature To is calculated by ^{(1 / x)} , and the calculated load factor U is substituted into the approximate expression of the insulating paper temperature, and the obtained insulating oil temperature is To Calculate the insulation paper temperature Tz of In the one having the first insulating paper temperature calculating means and the second data acquiring means, the load factor U obtained by dividing the acquired operating current of the diagnosed transformer by the rated current is approximated to the insulating paper temperature. Insulating sheet temperature Tz calculated by either the second insulating sheet temperature calculating means for calculating the insulating sheet temperature Tz by substitution and the first or second insulating sheet temperature calculating means, and the insulating sheet reference temperature Tzc The insulating paper temperature difference Tzs is calculated as the difference between the values, and the calculated insulating paper temperature difference Tzs is substituted into the calculation formula of the gradient correction coefficient R to calculate the gradient correction coefficient R, and the calculated gradient correction coefficient R is used as the reference A means for calculating the actual gradient K of the gradient reduction by multiplying the gradient Kc, a means for storing the degree of polymerization by time of the degree of polymerization lowered by the actual slope K in the degree of polymerization storage unit, and before the current time Used to calculate the degree of polymerization of A means for calculating the expected degree of decline in degree of polymerization of the future after the current time as the average value of the plurality of degrees of decline in degree of polymerization, and the estimated conditions input from the input unit (temperature of installation place for estimated area of transformer and load factor for estimated calculation) Means for calculating the future polymerization degree reduction trial calculation gradient under the calculation conditions according to the above-mentioned polymerization degree reduction gradient calculation means, and from the start of use of the diagnostic transformer read from the polymerization degree storage unit to the current time The transition of the degree of polymerization, the expected degree of polymerization along the gradient of the predicted decrease in degree of polymerization after the current time, and the trend of calculation of the degree of polymerization of the future after the current time along the gradient of the degree of polymerization decrease Means for displaying on the long-term polymerization degree transition graph from the start of use of the vessel to several decades, or means for displaying on the long-term polymerization degree transition graph, or several days from the present long-term polymerization degree transition graph Transformer deterioration state display apparatus characterized by comprising simultaneous display or means for alternating display, the short-term polymerization degree transition graph of.

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