JP2006024800A - Oil-immersed transformer remaining life/anomaly diagnostic system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil-immersed transformer remaining lifetime/anomaly diagnostic system for precisely, speedily, and reliably performing the diagnosis. <P>SOLUTION: The oil-immersed transformer remaining life/anomaly diagnostic system comprises a calculation means of calculating the temperature rise during operation of the object oil-immersed transformer, based on a temperature rise calculation formula worked out, by using data accumulated in an actually measured data compilation means; a simulation means for simulating a life loss/anomaly occurrence in the object oil-immersed transformer, based on the temperature rise value during operation worked out by the calculation means; a displaying means for displaying the data simulated by the simulation means; and an output means for outputting the data of the simulation displayed by the simulation means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention calculates the remaining life of the transformer by calculating the remaining part life of the oil-filled transformer and the temperature of the part that contributes to the abnormality diagnosis by a calculation formula devised based on the actual measurement value of the temperature. The present invention relates to an improvement of the remaining life / abnormality diagnosis system for oil-filled transformers, which makes it possible to perform abnormality diagnosis quickly and reliably with high accuracy.

  In general, an oil-filled transformer gradually deteriorates its insulation due to its operating temperature, oxygen, etc., and as its progress proceeds, abnormal voltage such as external lightning, internal lightning, etc. When subjected to mechanical and mechanical abnormal stress, the risk of destruction increases. And, it is said that the life of the oil-filled transformer is normally from the start of operation of the oil-filled transformer to the time when the degree of risk is very high. At present, it is very difficult and no specific method has been established for the detection.

In general, the life of an oil-filled transformer is most affected by the highest point temperature of the winding. For example, when establishing the transformer standard JEC-204 (1978), the relationship between the highest point temperature of the winding and the life Thorough consideration was added. According to the results of the study, in the regulations regarding temperature rise during operation of oil-filled transformers,
(1) Ambient temperature is constant at 25 ° C (2) Continuous use at rated load (3) Maximum oil temperature is 95 ° C
In this case, it is determined that a normal life of about 30 years can be expected.

However, in actual operation of the oil-filled transformer,
(1) Ambient temperature fluctuation (2) Load fluctuation (3) Difference between temperature test value and specified value (4) Changes in cooling conditions, etc. It is. In some cases, overload operation may be performed in a short time even at the expense of the life of the oil-filled transformer.

  As described above, in the overload operation of oil-filled transformers, the technical report (Part 1) 143 (oil-filled oil) Transformer operation guideline: Showa 61), which has been dealt with in the past (see Non-Patent Document 1, for example).

  Based on the above, today, various operation support systems such as transformer operation monitoring and abnormality prediction systems have been proposed for reliable operation during overload operation of oil-filled transformers. For example, in the oil-filled transformer remaining life diagnosis device disclosed in Japanese Patent Laid-Open No. 3-274473, the oil is calculated from the insulation oil temperature and the ambient temperature, or the secondary load current and the ambient temperature of the oil-filled transformer. The maximum winding temperature of the input transformer is calculated, and the remaining life of the oil-filled transformer is calculated based on the calculated temperature (see, for example, Patent Document 1).

Transformer Reliability Investigation Technical Committee “Oil-filled Transformer Operation Guidelines” The Institute of Electrical Engineers of Japan Technical Report (Part 1) No. 143 November 1986 1-2 JP-A-3-274473

  However, in the oil-filled transformer operation guideline (hereinafter referred to as the operation guideline) of the previous book [Non-Patent Document 1], oil-filled transformers are classified only by rated capacity, insulation class, and cooling method in order to have versatility. Because the time constant is set based on the rated capacity of the oil-filled transformer and the cooling method, individual data due to differences in the characteristics of each transformer is not adopted, so it corresponds to the characteristics of each oil-filled transformer. I couldn't.

  In addition, the relationship between the winding temperature rise value (including the oil temperature rise value) of the oil-filled transformer and the load also varies depending on the characteristics of each oil-filled transformer. However, in the above operation guidelines, it is very complicated to create guidelines based on individual characteristics of transformers, and certain standard characteristics are considered to be impractical. Is set to be safe in terms of temperature. For example, the allowable load of the oil-filled transformer when the time constant is 2.5H in the oil forced circulation system is set uniformly regardless of the characteristics of each oil-filled transformer.

  According to this setting, the overload allowable limit value and the overload time can be discriminated by a light load other than a heavy load. For example, if you want to operate an oil-filled transformer at 150% of the rated capacity, 1 hour 8 minutes when the light load is 50%, 49 minutes when the load is 70%, 27 minutes at 90%, and 15 minutes at 100%. Although it can be read, there is no telling what the actual temperature of the insulating oil or the actual temperature of the winding will be. In addition, even for light loads other than heavy loads, time calculation similar to the above is time-consuming and troublesome.

  Furthermore, although the equivalent ambient temperature is adopted in the above operation guidelines, this is a statistical calculation of the annual temperature or monthly average temperature in major regions throughout the country. Installation projects (indoors, outdoors, etc.) are not taken into consideration, and the environment of the oil-filled transformer installation site is not considered.

  Also, since the oil temperature of the oil-filled transformer is not calculated corresponding to the load current and the ambient temperature that change over time, for example, what time is the maximum temperature in one day, and how many times the temperature is However, there is a problem that it is difficult to predict the remaining life after the current time or abnormality determination.

  Next, in the later work [Patent Document 1], the maximum winding temperature of the oil-filled transformer is calculated, and the remaining life of the oil-filled transformer is calculated based on the temperature. The remaining life is simply a value obtained by subtracting the value obtained by converting the loss life obtained by actual measurement into 100% load from the normal life when operated at 100% load. There is a problem that the remaining life of the battery cannot be calculated.

  In view of the various problems described above, the present invention uses a formula for calculating a temperature rise value based on an actual measurement value such as a winding temperature actually measured over time in a prototype oil-filled transformer in advance. By calculating the temperature rise value at each part of the diagnosed oil-filled transformer and simulating the remaining life and abnormality occurrence of the diagnosed oil-filled transformer over time based on the calculated temperature rise value, It is an object of the present invention to provide an oil-immersed transformer remaining life / abnormality diagnosis system that allows quick, reliable and simple diagnosis of remaining life / abnormality of an input transformer.

  According to the first aspect of the present invention, the remaining life of the oil-filled transformer, such as the temperature of the insulating cylinder surrounding the winding switch, the lead conductor, and the switching switch operating mechanism of the on-load tap switching device, and the temperature of the part where the abnormality is diagnosed are operated. The oil-filled transformer of the oil-filled transformer that actually measures data over time according to a predetermined load factor and creates a data file, and the oil temperature that indicates the operating condition of the oil-filled transformer to be diagnosed The operation status detection means of the oil-filled transformer to be diagnosed that detects the operation data consisting of the load current and the load current over time, and the actual measurement data creation of the oil-filled transformer based on the operation status detected by the operation status detection means An arithmetic processing means for calculating a temperature rise value at the time of operation of the diagnostic oil-filled transformer based on a temperature rise value calculation formula devised based on data accumulated in the means, and calculated by the arithmetic processing means Leave when driving Simulation means for simulating life loss / abnormality generation of a diagnostic oil-filled transformer based on a temperature rise value, display means for displaying information simulated by the simulation means, and simulation information displayed by the display means are output Output means.

  The invention described in claim 2 is the oil-immersed transformer remaining life / abnormality diagnosis system according to claim 1, wherein the prototype oil-filled transformer used for acquiring the actual measurement data during operation by the actual measurement data creating means is It is characterized in that it is manufactured in the same design and / or substantially the same design as the diagnosed oil-filled transformer.

  According to a third aspect of the present invention, in the remaining life / abnormality diagnosis system for an oil-filled transformer according to the first aspect, the part for diagnosing the remaining life in the oil-filled transformer is a winding, and the abnormality diagnosis part is the It is an insulating cylinder surrounding the winding, the insulating oil in the tank, the lead conductor, and the switching switch operating mechanism of the on-load tap switching device.

  The invention according to claim 4 operates the temperature of the part that performs the remaining life and abnormality diagnosis of the oil-filled transformer, such as the temperature of the insulating cylinder surrounding the winding switch, the lead conductor, and the switching switch operating mechanism of the on-load tap switching device. Measured data creation means of oil-filled transformer that creates data file by actually measuring over time according to predetermined load factor with prototype prototype oil-filled transformer, and remaining life during operation of diagnosed oil-filled transformer Operating condition detection means for the oil-filled transformer to be diagnosed that detects the operation data of the part over time as a function of time and load factor as the temperature rise value of the part that contributes to the abnormality and the part that performs abnormality diagnosis, and the operating condition detection Based on the operation status detected by the means, based on the calculation formula for the temperature rise value based on the data accumulated in the actual data creation means of the oil-filled transformer, An arithmetic processing means for calculating a temperature rise value, a simulation means for simulating a life loss / abnormality occurrence of a diagnostic oil-filled transformer based on the temperature rise value during operation calculated by the arithmetic processing means, and the simulation means A display means for displaying simulated information and an output means for outputting simulation information displayed on the display means are provided.

  The invention according to claim 5 operates the remaining life of the oil-filled transformer and the temperature of the part that performs abnormality diagnosis, such as the temperature of the insulating cylinder surrounding the winding switch, the lead conductor, and the switching switch operating mechanism of the on-load tap switching device. The actual data creation means of the oil-filled transformer that creates data files by measuring over time according to a predetermined load factor with the prototype oil-filled transformer in the state, and the load that indicates the operating state of the oil-filled transformer to be diagnosed Based on the operation status detection means of the oil-in-transformer to be diagnosed that detects either current and cooling medium temperature or load current and ambient temperature over time, and the operation status detected by the operation status detection means, Arithmetic processing means for calculating a temperature rise value during operation of the diagnosed oil-filled transformer based on a formula for calculating the temperature rise value based on the data accumulated in the actual data creation means of the oil-filled transformer; Said arithmetic processing A simulation means for simulating life loss / abnormality generation of the diagnostic oil-filled transformer based on a temperature rise value during operation calculated by the means, a display means for displaying information simulated by the simulation means, and a display means Output means for outputting the displayed simulation information.

  According to a sixth aspect of the present invention, in the system for diagnosing the remaining life / abnormality of the oil-filled transformer according to the first aspect, the load current is a current on the secondary side of the oil-filled transformer to be diagnosed or a current on the primary side. It is current and connection tap information.

  According to the seventh aspect of the present invention, the remaining life of the oil-filled transformer and the temperature of the part that performs abnormality diagnosis, such as the temperature of the insulating cylinder surrounding the winding switch, the lead conductor, and the switching switch operating mechanism of the on-load tap switching device, are operated. Measured data creation means of oil-filled transformer that creates data file by actually measuring over time according to predetermined load factor with prototype prototype oil-filled transformer, and remaining life during operation of diagnosed oil-filled transformer Based on the operating condition detection means for the oil-in-transformer to be diagnosed that detects the temperature of the part that contributes to the part and the part that performs abnormality determination as the temperature at the current time, and the operating condition detected by the operating condition detection means An arithmetic processing means for calculating a temperature rise value during operation of the diagnosed oil-filled transformer based on a formula for calculating a temperature rise value based on data accumulated in the actual measurement data creating means of the oil-filled transformer Simulating means for simulating life loss / abnormality generation of the diagnostic oil-filled transformer based on the temperature rise value during operation calculated by the arithmetic processing means, and display means for displaying information simulated by the simulation means, Output means for outputting simulation information displayed by the display means.

  According to the eighth aspect of the present invention, the remaining life of the oil-filled transformer, such as the temperature of the insulating cylinder surrounding the winding switch, the lead conductor, and the switching switch operating mechanism of the on-load tap switching device is operated. Measured data creation means of oil-filled transformer that creates data file by actually measuring over time according to predetermined load factor with prototype prototype oil-filled transformer, and remaining life during operation of diagnosed oil-filled transformer Operating condition detecting means for the oil-immersed transformer to be diagnosed having a function of simulating the temperature of the part contributing to the condition and the part where the abnormality is judged assuming that the load fluctuation and the ambient temperature fluctuate, and the operating condition Based on the operation status detected by the detection means, based on the calculation formula of the temperature rise value based on the data accumulated in the actual data creation means of the oil-filled transformer, during operation of the diagnostic oil-filled transformer Oh Arithmetic processing means for calculating a temperature rise value, simulation means for simulating life loss / abnormality of the oil-in-transformer to be diagnosed based on the temperature rise value during operation calculated by the arithmetic processing means, and the simulation means Display means for displaying information simulated by the above and output means for outputting simulation information displayed on the display means.

The ninth aspect of the invention is the oil-filled transformer remaining life / abnormality diagnosis system according to any one of the first, fourth, fifth, eighth, and eighth aspects of the invention. The calculation formula of the temperature rise value at each part of the transformer is characterized by the following calculation formula based on the actual measurement data actually measured by the prototype oil-filled transformer.
[Equation 10]
Tc = (Tm−Tn) × exp ^{(−t / τ 2)} + Tn− (Tm × exp ^{(−t / τ 1)} )
However,
Tm: Maximum temperature increase value (° C.) of each part from the maximum oil temperature of the diagnostic oil-filled transformer immediately after the rated current is applied.
Tn: Temperature rise value (° C.) of each part from the maximum oil temperature of the oil-in-transformer to be diagnosed during continuous energization of the rated current.
t: energization time (a value indicating how much time has passed since the calculation start time is 0).
τ1: Time constant when the temperature from the maximum oil temperature suddenly increases at each part of the oil-filled transformer to be diagnosed immediately after the rated current is applied.
τ2: Time constant from when the temperature from the maximum oil temperature reaches the maximum value at each part of the oil-filled transformer to be diagnosed immediately after the rated current is applied until the value reaches a constant value.

  In the first aspect of the invention, a predetermined part of the oil-filled transformer to be diagnosed is based on actually measured values obtained by variously changing the rated load and load factor during operation using the prototype oil-filled transformer. A calculation formula for calculating the temperature rise value is devised. Based on the calculated formula, the temperature rise value at a predetermined part of the transformer is appropriately calculated and processed during operation of the oil-filled transformer to be diagnosed. Calculated (simulated), and based on the calculated value, it is now possible to accurately simulate the abnormality diagnosis and life loss of the transformer concerned, simplifying the life loss or abnormality occurrence of the oil-immersed transformer to be diagnosed As a result, it is possible to provide an oil-immersed transformer remaining life / abnormality diagnosis system with the excellent advantage of being able to use the oil-injected transformer to be diagnosed efficiently. Na .

  In the invention of claim 2, the calculation formula for calculating the temperature rise value of the diagnosed oil-filled transformer is various for the prototype oil-filled transformer having the same or substantially the same design as the diagnosed oil-filled transformer. By operating based on the load factor, we measured the temperature of the specified part and devised a formula for calculating the temperature rise based on the measured value. The temperature rise value used in the calculation can be calculated almost the same as the actual measured value of the prototype oil-filled transformer, so the life loss of the diagnosed oil-filled transformer can be calculated realistically and with high accuracy. It has the great advantage that it can be done.

  In the invention of claim 3, the part for detecting the temperature related to the remaining life in the prototype oil-filled transformer is a winding, and the part for measuring the temperature related to the abnormality is insulating oil. First, the measured values should be detected to cover the main components of the oil-immersed transformer to be diagnosed, such as the winding, the low-voltage lead conductor, and the insulation cylinder surrounding the switching switch operating mechanism of the on-load tap switching device. Since it is set, it is the basis for calculating the life loss and abnormality diagnosis of the oil-immersed transformer to be diagnosed, that is, calculating the temperature rise value by actually measuring the temperature of each part. Therefore, it is possible to devise the calculation formula realistically, and as a result, it is possible to accurately and accurately calculate the life loss and abnormality occurrence of the diagnostic oil-filled transformer.

  In the invention described in claim 4, in the prototype oil-filled transformer, the measured value data includes the winding temperature, the insulation oil temperature, the low-voltage lead conductor, etc. Since all the data for devising the calculation formula to be calculated has been created based on actual measurement values, it is assumed that the load factor has changed over time as the detection data to grasp the operating status of the oil-filled transformer to be diagnosed However, by substituting the load factor into the calculation formula for calculating the temperature rise value, it is easy to simulate the life loss and abnormality occurrence in the operating oil-in-transformer under diagnosis. It is possible to provide a system for diagnosing the remaining life and abnormality of oil-filled transformers, which has the excellent advantage that the transformer can be used efficiently.

  In the invention described in claim 5, in the prototype oil-filled transformer, the measured value data includes the winding temperature, the insulation oil temperature, the low-voltage side lead conductor, etc. Since all data for devising the calculation formula to be calculated are created by actual measurement values, the detection data for grasping the operation status of the oil-injected transformer to be diagnosed are load current, cooling medium oil (insulating oil), Or, even if it is either load current or ambient temperature, by substituting the detected value into the calculation formula for calculating the temperature rise value, the life loss or abnormal occurrence of the oil-immersed transformer under operation can be obtained. Since the simulation can be performed easily and with high accuracy, it is possible to provide a system for diagnosing the remaining life / abnormality of an oil-filled transformer having an excellent advantage that the diagnosed oil-filled transformer can be used efficiently.

  In the invention of claim 6, by detecting the load current, the temperature rise value at each part of the oil-filled transformer is quickly and reliably calculated and estimated based on the load factor. Therefore, the life loss / abnormality of the oil-filled transformer to be diagnosed can be calculated with high accuracy.

  In the invention described in claim 7, in the prototype oil-filled transformer, the measured value data including the winding temperature, the insulation oil temperature, the low-voltage lead conductor, etc. Since all data for devising the calculation formula to be calculated has been created by actual measurement values, when the detection data that grasps the operating status of the oil-in-transformer being diagnosed is detected over time as the current temperature, By substituting the detected value into the calculation formula for calculating the temperature rise value, it is possible to simulate the loss of life and occurrence of abnormality in the oil-immersed transformer under diagnosis with high accuracy and easily. It is possible to provide an oil-immersed transformer remaining life / abnormality diagnosis system having an excellent advantage that the diagnostic oil-filled transformer can be used efficiently.

  In the invention described in claim 8, in the prototype oil-filled transformer, the measured value data includes the winding temperature, the insulation oil temperature, the low-voltage lead conductor, etc. Since all data for devising the calculation formula to be calculated are created by actual measurement values, it is assumed that the detection data for grasping the operation status of the oil-injected transformer to be diagnosed changes in load fluctuation or ambient temperature Even if it is input as a result, by substituting the detected value into the calculation formula for calculating the temperature rise value, it is easy to simulate the life loss or abnormality occurrence in the oil-in-transformed transformer under operation, and Since it can be performed with high accuracy, it is possible to provide a system for diagnosing the remaining life and abnormality of an oil-filled transformer having an excellent advantage that the oil-filled transformer to be diagnosed can be used efficiently.

  In the invention according to claim 9, all the calculation formulas devised for calculating the temperature rise value of the winding of the diagnosis oil-filled transformer, etc. operate the prototype oil-fill transformer, The part that detects the temperature related to the remaining life of the transformer is the winding, and the part that measures the temperature related to the abnormality is the insulation oil, the winding, the lead conductor on the low voltage side, under load It is calculated on the basis of actual measurement data that covers the main components of the oil-filled transformer to be diagnosed, such as an insulating cylinder surrounding the switching switch operating mechanism of the tap switching device. As the basis for calculating the temperature rise value by actually measuring the temperature of each part, which is the basis for calculating the life loss, it is possible to devise the formula immediately As a result, the life loss of the oil-immersed transformer to be diagnosed accurately and It can be calculated well every time.

  Embodiments of the present invention will be described below with reference to FIGS. First, an oil-filled transformer of the same type as that of an oil-filled transformer to be diagnosed that performs the remaining life / abnormality diagnosis of oil-filled electrical equipment, that is, the same rated capacity (for example, 20 MVA) (They are simply referred to as oil-filled transformers). As shown in FIGS. 1 and 3, the oil-filled transformer 1 is provided with a cooling device 3 for cooling the insulating oil in the tank 2 by an oil forced circulation system outside the tank 2 through an oil conduit 4. Yes. The cooling device 3 cools the insulating oil by forcibly circulating the insulating oil between the tank 2 and the cooling device 3 with an oil pump 5 attached in the middle of the piping of the oil conduit 4.

  Next, as shown in FIG. 1, the oil-filled transformer 1 is provided with temperature sensors a to e including thermocouples or the like for detecting the temperature of a predetermined part. A shown in FIG. 1 is a temperature sensor for detecting a winding temperature, which is attached to detect temperatures of a plurality of portions of the winding 6 wound around the iron core 6a. b is a temperature sensor for detecting the temperature of the low-voltage side lead conductor 7 connected to the low-voltage side lead conductor derived from the winding 6. c is a temperature sensor installed in the upper part of the tank 2 so as to be immersed in the oil in order to detect the temperature of the insulating oil. d is a temperature sensor installed in an insulating cylinder provided on the outer periphery of the switching switch operating mechanism 10 of the on-load tap switching device 9; e is a temperature sensor for detecting the ambient temperature installed at the periphery of the oil-filled transformer 1.

  Each of the temperature sensors a to e individually sends a temperature detection signal (voltage) detected at a predetermined portion of the oil-filled transformer 1 to a detection temperature selector (multiplexer) 12. If the temperature sensor a is attached to a plurality of temperature sensors a in the same member, such as the temperature sensor a that detects the temperature of the winding 6 for each temperature sensor a to e, the detected temperature selector 12 is the temperature of the temperature sensor a. The temperature detection signals input to the sensor are arranged individually and sequentially output. The temperature detection signal input to the A / D converter 13 is converted into a digital signal and sent to a computer 14 having display / storage means and the like.

  The temperature detection signal sent to the computer 14 is, for example, a winding 6 or a low voltage for each temperature sensor a to e by a program for converting a voltage (V) built in the computer 14 into a temperature (° C.). The currently measured temperature of the side lead conductor 7 or the like is displayed on the display of the computer 14 and is stored over time in a storage device (not shown). The detected temperature selector 12, the A / D converter 13, and the computer 14 constitute actual measurement data creating means 15 for the oil-filled transformer 1.

The prototype oil-filled transformer 1 detects the temperature of the predetermined portion in advance by the temperature sensors a to e and creates the actual measurement data, which is the same as or substantially the same as the prototype oil-filled transformer 1 that is currently in operation. This is because the highest winding point temperature of the oil-filled transformer 21 shown in FIG. 2 of the same design cannot be directly measured (detected). That is, in the oil-filled transformer operation guideline (The Institute of Electrical Engineers of Japan Technical Report (Part 1) No. 143), ε (the difference between the highest winding point temperature and the average coil top temperature), εm (winding) The difference between the maximum point temperature and the winding average temperature) cannot be directly measured in an oil-filled transformer that is actually installed and operated. In FIG. 4, θ ₀ (maximum oil temperature rise), θw (winding average temperature rise), and σR (oil cooler upper and lower oil temperature difference) can be directly measured.

In the temperature distribution diagram shown in FIG. 4, since the temperature distribution of the oil-filled transformer that is actually operated is complicated, the following assumptions are provided for convenience in explaining the basic concept of the operation guideline. It was created. That is,
Assumption 1. The oil temperature rise increases linearly along the winding height. That is, if the generated loss of the winding is uniformly distributed along the height direction, and the oil rises uniformly along the cooling oil passage in the winding height direction, the above assumption is established. In this case, the oil temperature difference (NB-OA) between the upper and lower sides is determined from the generation loss of the windings and the oil flow rate through the cooling oil passage.
Assumption 2. The temperature rise of the winding increases linearly along the height of the winding in parallel with the oil temperature. That is, the difference g between the straight line CMD representing the winding temperature and the straight line ARB representing the oil temperature represents an average temperature increase with respect to the adjacent oil temperature of each coil constituting the winding. Actually, the generated loss and cooling conditions of the coils constituting one winding are not all the same, but for the sake of convenience, all of them are equal for the sake of convenience. Point E represents the highest winding point temperature. DE is the difference between the average temperature and the maximum temperature of the uppermost coil, which is determined by the shape of the coil, the shape arrangement of the coil support spacer, the difference in eddy current loss of each conductor in the coil, and the like.

And the symbol shown in FIG. 4 represents the following meaning.
θ _H : Winding maximum point temperature rise (° C)
θ ₀ : Maximum oil temperature rise (° C)
θ ₀ m: Average oil temperature rise (° C)
θw: Winding average temperature rise (℃)
g: Difference between winding average temperature and oil average temperature (℃)
εm: Difference between winding maximum point temperature and winding average temperature (℃)
ε: Difference between winding maximum point temperature and winding top coil average temperature (℃)

In the above, θ ₀ and θw can be directly measured by the temperature test. Further, θ ₀ m can be obtained from the following [Equation 1].

By obtaining the above θ ₀ m, g can be further obtained by the following [Formula 2].

  The problem here is that ε and εm cannot be measured as described above. For this reason, JEC-2200 (1995) normally estimates that εm at the rated load is 15 (° C) for natural oil circulation and 10 (° C) for oil forced circulation. As a base, θg at the rated load can be obtained by [Equation 3] of the following equation.

Although the value of εm or ε differs depending on individual design conditions in an actual oil-filled transformer, generally, the equation [Equation 3] is used. And winding maximum point temperature rise (theta) _H in the steady state at the time of applying a fixed load to an oil-filled transformer is given by following Formula [Formula 4].

However, when calculating (calculating) the maximum winding temperature rise θ _H shown in [Equation 4], the values of εm and ε described above differ from the design conditions of the individual oil-filled transformers. The maximum winding temperature rise θ _H of the transformer is calculated by calculating the difference θg (° C.) between the maximum winding temperature and the maximum oil temperature. Since it is short, there is a slight difference compared to the actual measurement value, which may cause subtle deviations in the remaining life of the oil-filled transformer, the timing of abnormality diagnosis, and the like.

Accordingly, the inventors of the present application have actually measured constants necessary for improving the calculation accuracy for calculating the accurate winding maximum point temperature rise θ _H by, for example, operating the prototype 20 MVA oil-filled transformer 1 at rated operation. The numerical values (temperatures and constants) derived from the actual measurements are as follows.

Tm ': Maximum winding temperature rise from the maximum oil temperature immediately after applying the rated current (℃)
Tn ': Winding temperature rise value in steady state from the maximum oil temperature when the rated current is continuously applied (℃)
τ1: Time constant when the winding temperature suddenly rises immediately after applying the rated current τ2: Time constant n until the winding temperature drops to a constant value immediately after the rated current is supplied : Value representing the relationship between winding temperature rise and load factor m: Value representing the relationship between oil temperature rise and load factor

  Next, in order to derive the numerical values of Tm ′, Tn ′, τ1, τ2, n, m, the operation of the oil-filled transformer 1 is, for example, when each part is operated continuously for a predetermined time at a load factor of 75%. The temperature of was measured.

FIG. 6 is a temperature rise characteristic diagram of the winding 6 measured by operating the oil-filled transformer 1 with a rated load. As can be seen from the figure, the temperature of the winding 6 rapidly increases immediately after energization (time constant: about 6.5 minutes), and the temperature increase value reaches a peak within several tens of minutes. Thereafter, the winding temperature gradually decreases and becomes substantially constant after several hours (after about 4 hours have elapsed). The winding temperature rise characteristics shown in FIG. 6 are analyzed in detail, and the Tm ′, Tn ′, τ1, and τ2 as measured values for obtaining the temperature rise value Tc of the winding 6 are shown in FIG. It is obtained from the winding temperature rise characteristic diagram (graph) shown (see steps S1 and S2 in FIG. 5).

  For calculating the values of n and m, the oil-filled transformer 1 is based on a predetermined load factor (for example, an arbitrary load factor such as 100% continuous operation, 77% continuous, 50% continuous, 90% continuous). Can be obtained by continuous operation. That is, based on the winding temperature and oil temperature at each load factor, the values of n and m indicating the relationship between the load factor and the temperature rise value (saturation value at a constant load) are calculated.

  The n value (value indicating the relationship between the winding temperature and the load factor) can be generally obtained by the following equation [5].

Where θg: difference between maximum winding temperature and maximum oil temperature at load factor K (° C)
θgn: Difference between winding maximum point temperature and maximum oil temperature at rated load (℃)
K: Ratio of current (current load) that is currently energized to the rated current (rated load) (value indicating the load factor)
n: Constant determined by the cooling method (value representing the relationship between winding temperature and load factor)

  Further, the m value (value indicating the relationship between the oil temperature and the load factor) can be obtained by the following equation [Equation 6] as in the case of the n value.

here,
θ ₀ : Maximum oil temperature rise (° C)
θ ₀ n: Maximum oil temperature rise at rated load (° C)
K: Ratio of current (current load) that is currently energized to rated current (rated load) (load factor)
R: Ratio of load loss at rated load to no-load loss m: Constant determined by the cooling method (value representing the relationship between oil temperature and load factor)

  Next, a case will be described in which Tm ′, Tn ′, τ1, and τ2 are derived as actual measurement values when the temperature rise value Tc of the low-voltage-side lead conductor 7 is obtained. In this case as well, the temperature of the low-voltage side lead conductor 7 is measured by the operation of the oil-filled transformer 1 in the same manner as when the winding temperature is actually measured, and the Tm based on the temperature rise characteristic diagram (see FIG. 10). ', Tn', τ1, τ2 are obtained.

Tm ': Maximum temperature rise value of the low pressure side lead conductor (° C) from the maximum oil temperature immediately after applying the rated current
Tn ': Increased temperature of the low-pressure side lead conductor (° C) from the maximum oil temperature immediately after the rated current is continuously energized
τ1: Time constant when the low-voltage-side lead conductor temperature rapidly increases immediately after applying the rated current τ2: From the time when the low-voltage-side extraction conductor temperature reaches the maximum value immediately after applying the rated current Time constant n: Value representing the relationship between the low temperature side lead conductor temperature rise and the load factor m: Value representing the relationship between the oil temperature rise and the load factor

  In the above, in the calculation of the n and m values, the oil-filled transformer 1 is operated for each predetermined load factor in the same manner as when the n and m values in the winding 6 are obtained, and according to each load factor. Since the mathematical formula to be calculated is the same as [Formula 5] and [Formula 6] used in the case of the winding 6, the description is omitted. However, in [Equation 5], the highest point temperature of the winding 6 is read as the highest point temperature rise of the low-voltage side lead conductor 7.

Further, when Tm ′, Tn ′, τ1, and τ2 are derived as actual measured values when the temperature rise value Tc of the insulating cylinder surrounding the switching switch operating mechanism 10 of the on-load tap switching device 9 is derived, It is obtained from the temperature rise characteristic diagram (see FIG. 14) of the insulating cylinder measured by operating the oil-filled transformer 1 in the same manner as when the temperature of the line 6 and the low-voltage side lead conductor 7 was measured. For calculating the n and m values, the oil-filled transformer 1 is subjected to a predetermined load factor in the same manner as when the n and m values of the winding 6 and the low-voltage side lead conductor 7 are calculated. The calculation is performed in accordance with each load factor, and the calculation formula in this case is the same as [Equation 5], and thus the description thereof is omitted. At that time, the highest point temperature of the winding 6 and the highest point temperature rise of the low-voltage side lead conductor 7 are read as the highest point temperature of the insulating cylinder.
Tm ': Maximum temperature rise of the insulation cylinder from the maximum oil temperature immediately after applying the rated current (℃)
Tn ': Insulating cylinder temperature rise value (° C) at steady state from the maximum oil temperature immediately after continuous energization of the rated current
τ1: Time constant when the insulation cylinder temperature rapidly increases immediately after the rated current is applied τ2: Time constant n until the insulation cylinder temperature reaches a constant value immediately after the rated current is supplied : Value representing the relationship between the insulation cylinder temperature and the load factor m: Value representing the relationship between the oil temperature rise and the load factor

  As described above, in the present invention, actual measurement data obtained by operating the oil-filled transformer 1 at a rated load, that is, each part of the oil-filled transformer 1 (winding 6, low-voltage side lead conductor 7, The oil-filled transformer shown in FIGS. 6, 10, and 14 is Tm ′, Tn ′, τ 1, and τ 2 in an insulating cylinder (hereinafter simply referred to as an insulating cylinder) surrounding the switching switch operating mechanism 10 of the load tap changer 9. 1 By operating the oil-filled transformer 1 by appropriately changing each temperature constant and load factor obtained from the temperature rise characteristic diagram of each part, the temperature, oil temperature and load factor of each part of the oil-filled transformer 1 The values of n and m obtained by calculating the relationship between the measured data and the measured data are stored in the computer 14 of the measured data creating means 15 until the measured data is required.

  Then, based on the constants of Tm ′ and Tn ′ stored in the computer 14, Tm (maximum temperature rise value in each part immediately after load change) and Tn (oil temperature rise value during rated load operation) It is obtained by [Expression 7] and [Expression 8].

here,
K: Ratio of current (current load) that is currently energized to the rated current (rated load) (value indicating the load factor)
n: Constant determined by the cooling method (value representing the relationship between winding temperature and load factor)

  The Tm and Tn in each part of the oil-filled transformer 1 obtained by the [Equation 7] and [Equation 8] are stored in the storage unit of the computer 14. As described above, in the present invention, as shown in FIG. 1, the prototype oil-filled transformer 1 is assumed to have various load factors in the same manner as the oil-filled transformer actually installed in the distribution system. And the data of Tm ′, Tn ′, τ1, τ2 related to the low-voltage side lead conductor 7 and the insulating cylinder, including the winding 6 of the oil-filled transformer 1 measured by this operation, and the above [Equation 7], The temperature rise values of Tm and Tn calculated by the equation shown in [Equation 8] are created by the actual measurement data creation means 15 and stored in the computer 14 constituting the creation means 15.

Next, a case where the maximum oil temperature rise θ ₀ is obtained will be described. Note that, for example, when the maximum oil temperature is measured by the temperature sensor g shown in FIG. The maximum oil temperature rise θ ₀ when the load factor is changed is generally obtained by the calculation formula shown in [Equation 9] below.

here,
θu: Maximum oil temperature rise at rated load factor θi: Initial maximum oil temperature rise (t = 0)
t: elapsed time τ: oil temperature change time constant (time)

  Next, the oil temperature change time constant τ used in the formula of [Equation 9] is read from the temperature rise curve of the insulating oil at the rated load in the prototype oil-filled transformer 1.

  The present invention is obtained by operating the oil-filled transformer 1 based on a required load factor, and measuring the temperature of each part (winding 6, low-voltage side lead conductor 7, insulating cylinder, oil temperature). In order to calculate the temperature rise value Tc at each part of the diagnostic oil-filled transformer 21 currently in operation shown in FIG. 2 by using the various data obtained at each part (based on the various measured data). Was calculated based on the above [Equation 7] and [Equation 8]. This calculation formula is a calculation formula shown in the following [Equation 10], and the temperature increase value Tc in each part of the diagnosed oil-filled transformer 21 can be obtained from [Equation 10] by determining the oil temperature and the load factor (load current). By adding the oil temperature at that time and the temperature rise value Tc, the temperature at each part can be obtained (see step S4 in FIG. 5).

here,
Tm: Maximum temperature rise value (° C.) of each part from the maximum oil temperature of the diagnostic oil-filled transformer 21 immediately after applying the rated current
Tn: Temperature rise value (° C.) of each part from the maximum oil temperature of the diagnosed oil-filled transformer 21 when the rated current is continuously energized
t: energization time (value indicating how much time has passed since the calculation start time was set to 0)
τ1: Time constant when the temperature from the maximum oil temperature suddenly rises at each part of the diagnosed oil-filled transformer 21 immediately after the rated current is energized τ2: Diagnose oil-immersed transformer immediately after the rated current is energized The time constant from when the temperature from the maximum oil temperature reaches the maximum value to the constant value at each part of 21

  Tm and Tn are values that change depending on the load factor K of the oil-in-transformed transformer 21 to be diagnosed, and the load factor K is detected by detecting the load current flowing on the secondary side of the oil-in-transformed transformer 21 to be diagnosed. I understand. Therefore, the Tm can be obtained from [Equation 11] shown below, and Tn can be obtained from [Equation 12] (see Step S6 in FIG. 5).

here,
Tm ′: Maximum temperature rise value (° C.) from the maximum oil temperature in each part of the oil-in-transformer 21 to be diagnosed immediately after the rated current is applied
Tn ′: Temperature rise value (° C.) from the maximum oil temperature in the steady state of the oil-in-transformer 21 to be diagnosed when the rated current is continuously energized
K: Ratio of current (current load) that is currently energized to rated current (rated load) (load factor)
n: Constant determined by the cooling method (value indicating the relationship between the temperature of the predetermined part and the load factor)
Tm ′, Tn ′, K, and n are all oil temperature time constants corresponding to constants (values) measured when the prototype oil-filled transformer 1 is operated, and also in terms of temperature rise values. These are oil temperature time constants corresponding to constants (temperatures) measured in each part of the oil-filled transformer 1 (winding 6, low-voltage side lead conductor 7, insulating cylinder). That is, it goes without saying that the time constant of the oil temperature is a time constant when the oil temperature rises after the load of the diagnostic oil-filled transformer 21 changes.

  As shown in FIG. 2, the diagnosis oil-filled transformer 21 (the same members as those of the oil-filled transformer 1 are described by the same reference numerals) has a temperature for detecting the temperature of the insulating oil at a predetermined portion in the tank 2. A sensor g is attached. And this temperature sensor g is installed in the uppermost part in the tank 2, as shown in FIG. The temperature sensor h detects the ambient temperature of the oil-in-transformer 21 to be diagnosed.

  Next, in FIG. 2, reference numeral 22 denotes a means for grasping the operating condition of the diagnosed oil-filled transformer 21, and this operating condition grasping means 22 is used for grasping the operating condition of the diagnosed oil-filled transformer. The oil temperature detected by the temperature sensor g installed in the required oil of the diagnosed oil-filled transformer 21 and the temperature information around the diagnosed oil-filled transformer 21 (detected by the temperature sensor h) are in operation. The load current of the oil-injected transformer 21 to be diagnosed is detected, and the operating state detecting means 23 of the oil-injected transformer 21 to be diagnosed and the temperature / current information are converted into a data file; 15, the actual measurement data file 24 in which the actual measurement data of the oil-filled transformer 1 and the calculation formulas shown in the above [Equation 7] to [Equation 12] are filed, and the diagnostic oil-immersed transformer 21 Based on actual measured values of oil-filled transformer 1 based on operating conditions For example, the temperature rise value Tc during the operation of the diagnostic oil-filled transformer 21 is calculated (simulated) by the calculation formula (see [Equation 10]) for calculating the temperature rise value Tc of the winding 6, for example. ) And a simulation for simulating the life loss of the diagnostic oil-filled transformer 21 based on the temperature rise value Tc calculated by the arithmetic processing means 25 using a predetermined calculation formula to be described later. Means 26, display means 27 for displaying the contents of the life loss calculated by the simulation means 26, and the display contents displayed by the display means 27 are output to the management means 28 such as a computer installed in a monitoring station ( Output means 29 for transmission). The contents of the transmission life loss output from the output means 29 are displayed by the management means 28 and stored and stored so that the display data can be taken out at any time.

  Next, the case where the temperature rise value Tc at the predetermined part of the diagnostic oil-filled transformer 21 is calculated will be described. First, in FIG. 2, the oil temperature of the diagnosed oil-filled transformer 21 is detected by a temperature sensor g installed in the insulating oil of the diagnosed oil-filled transformer 21. Further, a load current (for example, secondary side) during operation of the diagnostic oil-filled transformer 21 is detected, and the load factor K is determined. As described above, when the above preparatory work is completed in advance, the current temperature rise value in the winding 6 is calculated by the calculation formula shown in [Equation 10] based on the various detection data.

  In calculating the temperature rise value Tc according to the above [Equation 10], Tm is calculated by the equation of [Equation 11] based on the oil temperature detected by the temperature sensor g, and Tn is also calculated from the temperature sensor. The oil temperature detected by g is used as a base, and is calculated by the formula of [Equation 12]. Then, when Tm and Tn are calculated by the equations [Equation 11] and [Equation 12], the temperature rise value Tc (estimated value) of the winding 6 is obtained by substituting these Tm and Tn into [Equation 10]. .

Then, the maximum oil temperature increase value θ ₀ of the insulating oil at the time when Tc is calculated is obtained from [Equation 9] to the temperature increase value Tc calculated in [Equation 10], and the maximum oil temperature calculated at this time is calculated. Add the temperature rise value Tc calculated in [Equation 10] and the ambient temperature to the rise value θ ₀ , or add the calculated temperature rise value Tc to the oil temperature detected by the temperature sensor g. By doing this, it is possible to grasp (estimate) the temperature of the winding 6 in the diagnosed oil-filled transformer 21 currently in operation. When the calculated temperature of the winding 6 is equal to or higher than the limit value of the winding temperature (for example, 160 ° C.), it is displayed on the display means 27 of the operation status grasping means 22 that an abnormality has occurred in the winding 6. An alarm is issued to notify that an abnormality has occurred. In addition, a monitoring station (not shown) or the like is notified via the output means 29 that an abnormality has occurred in the diagnostic oil-filled transformer 21 (see steps S7 to S9 in FIG. 5).

Further, even when the maximum oil temperature rise value θ ₀ exceeds 120 ° C., for example, an abnormality has occurred as in the case of the temperature rise of the winding 6, and an abnormality alarm is displayed on the display means 27. It is transmitted to the monitoring station or the like by the output means 29 of the driving condition grasping means 22.

  On the other hand, when the temperature of the winding 6 and the oil temperature are lower than the limit values, respectively, the life loss of the diagnostic oil-filled transformer 21 currently in operation can be obtained by calculation described later.

  When the temperature rise value Tc related to the temperature of the winding 6 of the diagnostic oil-filled transformer 21 during operation is calculated, the temperature rise value Tc is continuously operated at a rated load of 50%, for example. If the load factor is changed to 120% for some reason during the operation in the state and the operation is continued, the temperature characteristic diagram is drawn based on the temperature rise value Tc calculated as described above. As shown in FIG. 18, when the load factor is 120% and continuously operated for 2 hours, the temperature rise value Tc of the winding 6 is higher than that when continuously operated at the load factor of 50%. When the prototype oil-filled transformer 1 was actually operated and confirmed, it was found that it was almost the same as the temperature characteristic diagram (see FIG. 7) when operated at a load factor of 120% for 2 hours. In other words, it was found that the measured values obtained in advance under the same conditions (same load factor and operation time) by the same kind of oil-filled transformer 1 were almost the same as the actual measured values.

  Similarly, as shown in FIGS. 18 to 20, the oil-filled transformer is also used in the operation of the diagnosed oil-filled transformer 21 when the load factor of the diagnosed oil-filled transformer 21 changes from 120% to 160%. 1 was compared with the actually measured value when operated under the same conditions as described above, it was found that almost the same temperature rise value (see FIGS. 7 to 9) was obtained.

  When the temperature rise value Tc of the winding 6 during operation of the diagnosed oil-filled transformer 21 is obtained by the calculation formula shown in [Equation 10] as described above, the low-voltage side lead conductor of the diagnosed oil-filled transformer 21 continues. 7 and the temperature rise value Tc of the insulating cylinder of the switching switch operating mechanism 10 of the on-load tap switching device 9 is obtained. In this case as well, the temperature rise value Tc of the winding 6 is obtained in the same manner as that calculated.

  That is, in the oil-in-transformer 21 to be diagnosed, when calculating the temperature rise value Tc of the low-voltage side lead conductor 7, Tm is calculated by the formula of [Equation 11], and Tn is expressed by [Equation 12]. Calculate by calculation. When Tm and Tn for calculating the temperature rise value Tc of the low-voltage side lead conductor 7 are calculated as described above, by substituting these Tm and Tn values into the calculation formula shown in [Equation 10], The temperature rise value Tc (estimated value) of the lead conductor 7 is obtained.

  Further, when the temperature rise value Tc of the insulating cylinder surrounding the switching switch operating mechanism 10 used in the on-load tap switching device 9 is obtained, the temperature rise value Tc of the winding 6 and the low-voltage side lead conductor 7 is also obtained. In the same manner as described above, based on the oil temperature detected by the temperature sensor g, first, the values of Tm and Tn are obtained by the formulas of [Equation 11] and [Equation 12], and the values of Tm and Tn are obtained by [Equation 10]. ], The temperature rise value Tc of the insulating cylinder is calculated.

Then, the maximum oil temperature rise value θ ₀ obtained by the calculation formula shown in [Equation 6] and the temperature rise value Tc of the low-voltage side lead conductor 7 and the insulating cylinder, respectively, or the oil temperature detected by the temperature sensor g When the added value is equal to or higher than the limit temperature of the low-voltage side lead conductor 7 or the insulating cylinder, it is determined that an abnormality has occurred, and this is displayed on the display means 27 and via the output means 29. Informing a monitoring station (not shown) that an abnormality has occurred in the oil-filled transformer 21 to be diagnosed.

  Further, when the temperature characteristic diagram is created based on the temperature rise value Tc of the low voltage side lead conductor 7 and the insulating cylinder calculated by the formula of [Equation 10], for example, in the low voltage side lead conductor 7, The temperature characteristics (see FIGS. 21 to 23) when continuously operated at 120%, 140%, and 160% for 2 hours each are shown in FIG. 11 to FIG. 13), it was found to be almost the same.

  Also in the insulating cylinder, when compared with the load factors of 120%, 140%, and 160% in the same manner as described above, temperature characteristic diagrams created based on the temperature rise value Tc calculated by [Equation 10] (FIGS. 24 to 26). (See FIG. 15 to FIG. 17) created by actual measurement values measured with the oil-filled transformer 1 were found to be almost the same.

  As described above, in the present invention, when calculating the temperature rise value Tc at a predetermined portion of the diagnosed oil-filled transformer 21, a prototype oil-filled transformer having the same or substantially the same design as the diagnosed oil-filled transformer 21 in advance. The temperature of a part related to the remaining life / abnormality diagnosis (insulation cylinder covering the switching switch operating mechanism 10 of the on-load tap switching device 9 and the tap selector 11) and the tap selector 11 in the container 1 The oil temperature is measured in relation to the ambient temperature, and Tm (the maximum temperature rise value from the oil temperature at each part immediately after the rated load energization) and Tn (at the rated load continuous operation) are based on the actually measured values. The temperature rise value from the oil temperature at each part of the diagnostic oil-filled transformer is determined by [Equation 7] and [Equation 8].

  Then, a calculation formula for calculating the temperature rise value Tc of each part of the diagnostic oil-filled transformer 21 based on the calculated Tm and Tn is devised as shown in [Equation 10]. The temperature rise value Tc in each part of the diagnosed oil-filled transformer 21 is calculated by the calculated formula shown in [Equation 10]. In the calculation formula shown in [Equation 10], Tm and Tn are temperature rises. Based on the oil temperature of the predetermined part (the winding 6 of the oil-in-transformer 21 to be diagnosed, the low-voltage side lead conductor 7 and the insulating cylinder) for obtaining the value Tc and the load factor of the oil-in-transformer 21 to be diagnosed [Equation 11 ] And [Equation 12], the calculated Tm and Tn are substituted into [Equation 10] to obtain the temperature rise value Tc of each part in the oil-in-transformer 21 to be diagnosed.

When the temperature rise value Tc calculated in [Equation 10], the maximum oil temperature rise value θ _0, and the ambient temperature are added and the added value is equal to or higher than the limit temperature of the predetermined part, the part related to the temperature rise value Tc (For example, the winding 6) is configured so as to warn the relevant person that it is determined to be abnormal and to notify the person concerned of the abnormality by displaying it or the like.

Next, the life loss of the diagnosed oil-filled transformer 21 is obtained based on the temperature rise value Tc of the diagnosed oil-filled transformer 21. In this case, for example, it is calculated from the following formula shown as [Equation 13] expanded from the formula shown in “Oil-filled transformer operation guideline” shown in Technical Report (Part 1) No. 143 of the Institute of Electrical Engineers of Japan. To do. In this case, assuming that the normal life when the predetermined part of the oil-filled transformer 21 to be diagnosed is operated at the maximum winding point temperature of 95 ° C. is Y ₀ , the life loss V during the time t (relative to the normal life Y ₀₎ . This is a calculation formula for calculating the degree of loss.

here,
Y ₀ : Regular life b: Constant (0.1155 at 80 ° C. to 150 ° C.)
θ: Temperature rise value (Tc) calculated by [Equation 10]
0 to t: life loss within a predetermined time dt: calculation time step e: exponential function

  In the life loss calculated by the above [Equation 13], if the calculation result V = 1, it means that the life of the diagnostic oil-filled transformer 21 has been reached. Then, by calculating the life loss, the diagnosed oil-filled transformer 21 can operate continuously at the winding temperature of 95 ° C. for 30 years when the operation is continued at the current load factor. This indicates that the life is lost for the time of V with respect to the standard of the normal life. When the life loss V is calculated, it is displayed by the display means 27 and transmitted to the monitoring station management means 28 (not shown) by the output means 29, and is displayed / stored (see steps S10 to S12 in FIG. 5). ).

  As described above, the present invention includes an insulation cylinder such as the winding 6 measured using the prototype oil-filled transformer 1, the low-voltage side lead conductor 7, the switching switch operating mechanism 10 of the on-load tap switching device 9, and the like. A plurality of patterns are actually measured in consideration of a predetermined load factor and ambient temperature for each oil temperature, and a calculation formula [Equation 10] for calculating a temperature rise value Tc of each part of the oil-in-transformer 21 to be diagnosed based on the actually measured values. The temperature rise value Tc of the diagnosed oil-filled transformer 21 is calculated (simulated) using this calculation formula. Then, based on the calculated temperature rise value Tc, how long the diagnosed oil-filled transformer 21 can be used by simulating the life loss and abnormality occurrence of the diagnosed oil-filled transformer 21 in advance. That is, it is convenient because it is possible to calculate life loss and abnormality occurrence with high accuracy and promptly and reliably.

  As described above, the simulation of the life loss and abnormality occurrence of the diagnosed oil-filled transformer 21 is performed by calculating the temperature rise value Tc of the diagnosed oil-filled transformer 21 using the calculation formula of the present invention. When the temperature rise of a predetermined part is plotted on the graph based on the temperature rise value Tc, the temperature rise shown in the drawn graph is actually the same by the prototype oil-filled transformer 1 having the same design or the same design. When the temperature of the actually measured value is graphed, the former and the latter are represented in a substantially matched state. This is because the calculation formula for calculating the temperature rise value Tc of the diagnosed oil-filled transformer 21 is devised based on the actually measured data. Since the temperature rise value Tc of each part in can be calculated with substantially the same value as when actually measuring the temperature, as long as the temperature rise value Tc calculated by the calculation formula of the present invention is used as a base, the oil to be diagnosed Since the remaining life and abnormality occurrence of the input transformer 21 can be calculated with high accuracy, the maintenance management of the oil-in-transformer 21 to be diagnosed can be performed smoothly and satisfactorily.

  In the present invention, the load current is described as the current flowing in the secondary side of the oil-filled transformer 1 or the oil-filled transformer 21 to be diagnosed. However, the present invention is not limited to this, and the primary current or tap number can be found. Needless to say, the load current can be detected and used by them. Further, when calculating the temperature rise value Tc of the diagnostic oil-filled transformer 21, it can be easily calculated by satisfying either the load current and the oil temperature or the load current and the ambient temperature. Assuming the temperature of each part of the oil-filled transformer 21 to be diagnosed in advance, this is input as the actual temperature to the operating condition detecting means 23, and the temperature rise value Tc is calculated based on the data, and the value is simulated. Thus, the present invention can be established even if a life loss or abnormality diagnosis of the oil-in-transformer 21 to be diagnosed is performed.

In a prototype oil-filled transformer, it is a schematic block diagram in the case of detecting the temperature of the predetermined part of the said transformer. It is a schematic block diagram in the case of grasping | ascertaining the remaining life etc. of a to-be-diagnosed oil-filled transformer with the remaining life and abnormality diagnosis system of this invention. It is a side view of a diagnostic oil-filled transformer. It is a temperature distribution map of an oil-filled transformer. It is a flowchart figure for demonstrating schematically execution of the system of this invention. It is a characteristic view which shows the change of winding temperature rise. It is a temperature characteristic figure which shows the actual value of a coil | winding and an oil temperature at the time of driving | running an oil-filled transformer for 50% of load ratios and 120% for 2 hours. It is a temperature characteristic figure which shows the actual value of a coil | winding and an oil temperature at the time of driving | running an oil-filled transformer for 50% of a load factor continuously for 140% for 2 hours. It is a temperature characteristic figure which shows the actual value of a coil | winding and an oil temperature at the time of operating a load factor 50% continuous and 160% for 2 hours. It is a characteristic view which shows the change of the temperature rise of a low voltage | pressure side lead conductor. It is a temperature characteristic figure which shows the measured value of a low voltage | pressure side lead conductor and oil temperature at the time of operating an oil-filled transformer for 50% of load ratios, 120% for 2 hours. It is a temperature characteristic figure which shows the measured value of a low voltage | pressure side extraction conductor and oil temperature at the time of driving | running an oil-filled transformer for 50% of load rates and 140% for 2 hours. It is a temperature characteristic figure which shows the measured value of a low voltage | pressure side lead conductor and oil temperature at the time of driving | running an oil-filled transformer for 50% of load factor continuously for 160% for 2 hours. It is a characteristic view which shows the change of an insulation cylinder temperature rise. It is a temperature characteristic figure which shows the measured value of an insulation cylinder temperature at the time of driving | running an oil-filled transformer for 50% of load factors continuously and 120% for 2 hours. It is a temperature characteristic figure which shows the measured value of an insulation cylinder temperature at the time of driving | running an oil-filled transformer for 50% of load factors continuously for 140% for 2 hours. It is a temperature characteristic figure which shows the measured value of an insulation cylinder temperature at the time of driving | running an oil-filled transformer for 50% of load factors continuously for 160% for 2 hours. It is a winding temperature characteristic figure which calculates and calculates the winding temperature when a diagnostic oil-filled transformer is operated at a load factor of 50% continuously for 120% for 2 hours based on actual winding constants. It is a winding temperature characteristic figure which calculates and calculates the winding temperature when a diagnostic oil-filled transformer is operated at a load factor of 50% continuously for 140% for 2 hours based on actual winding constants. It is a winding temperature characteristic figure which calculates and calculates the winding temperature when a diagnostic oil-filled transformer is operated at a load factor of 50% continuously for 160% for 2 hours based on actual winding constants. It is a low-pressure side lead conductor temperature characteristic figure which calculates and calculates the low-pressure side lead conductor temperature by the actual measurement constant when a diagnostic oil-filled transformer is operated for 120% for 2 hours at a load factor of 50%. It is a low-pressure side lead conductor temperature characteristic figure which calculates the low-pressure side lead conductor temperature when operating a diagnostic oil-filled transformer for 50% of a load factor continuously for 140% for 2 hours by the actual measurement constant. It is a low-pressure side lead conductor temperature characteristic figure which calculates and calculates the low-pressure side lead conductor temperature by the actual measurement constant when a diagnostic oil-filled transformer is operated for 160% for 2 hours at a load factor of 50%. It is an insulation cylinder temperature characteristic figure which calculates and calculates the insulation cylinder temperature when the diagnostic oil-filled transformer is operated at a load factor of 50% continuously for 120% for 2 hours. It is an insulation cylinder temperature characteristic figure which calculates and calculates the insulation cylinder temperature when the diagnostic oil-filled transformer is operated with a load factor of 50% continuously for 140% for 2 hours. It is an insulation cylinder temperature characteristic figure which calculates and calculates the insulation cylinder temperature when a diagnostic oil-filled transformer is operated for 50% of a load factor continuously for 160% for 2 hours.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Prototype oil-filled transformer 2 Tank 3 Cooling device 4 Oil conduit 5 Oil pump 6 Winding 7 Low voltage side lead conductor 9 Load tap switching device 10 Switching switch operating mechanism 11 Tap selector 12 Detection temperature selector 13 A / D converter 14 Computer 15 Actual measurement data creation means 21 Diagnosed oil-filled transformer 22 Operating condition grasping means 23 Operating condition detection means 24 Actual measurement data file 25 Arithmetic processing means 26 Simulation means 27 Display means 28 Management means 29 Output means a to e, g, h Temperature sensor Tc Temperature rise value

Claims (9)

Prototype oil-immersed transformer with operating conditions such as the temperature of the insulation cylinder surrounding the switching switch operating mechanism of the winding, lead conductor, load tap changer, etc. Operation consisting of measured data creation means of oil-filled transformer that creates data files by actually measuring over time according to a predetermined load factor, and oil temperature and load current indicating the operating state of the diagnosed oil-filled transformer Based on the operation status detection means of the oil-filled transformer to be diagnosed that detects data over time, and the data accumulated in the actual data creation means of the oil-filled transformer based on the operation status detected by the operation status detection means Based on the calculation formula for the temperature rise value devised in this way, the arithmetic processing means for calculating the temperature rise value during operation of the diagnostic oil-filled transformer, and the temperature rise value during operation calculated by the arithmetic processing means Based on Simulation means for simulating life loss / abnormality generation of diagnostic oil-filled transformer, display means for displaying information simulated by the simulation means, and output means for outputting simulation information displayed by the display means An oil-immersed transformer remaining life / abnormality diagnosis system characterized by   The prototype oil-filled transformer used for acquiring the actually measured data during operation by the measured data creating means is the same as the diagnosed oil-filled transformer and / or substantially the same design as the diagnosed oil-filled transformer. 2. The residual life / abnormality diagnosis system for an oil-filled transformer according to claim 1, wherein the system is manufactured.   The part for diagnosing the remaining life in the oil-filled transformer is a winding, and the abnormality diagnosis part surrounds the winding, the insulating oil in the tank, the lead conductor, and the switching switch operating mechanism of the on-load tap switching device. 2. The remaining life / abnormality diagnosis system for an oil-filled transformer according to claim 1, wherein the system is an insulating cylinder. Prototype oil-immersed transformer with operating conditions such as the temperature of the insulation cylinder surrounding the switching switch operating mechanism of the winding, lead conductor, load tap changer, etc. The measurement data creation means of the oil-filled transformer that creates data files by actually measuring over time according to a predetermined load factor, and the part and abnormality diagnosis that contribute to the remaining life during operation of the oil-filled transformer to be diagnosed The temperature rise value of the part to be performed is a function of time and load factor, and the operation data of the diagnostic oil-filled transformer that detects the operation data of the part over time and the operation condition detected by the operation condition detection means In addition, a temperature rise value during operation of the diagnosed oil-filled transformer is calculated based on a formula for calculating a temperature rise value based on data accumulated in the actual measurement data creation means of the oil-filled transformer. An arithmetic processing means, a simulation means for simulating a life loss / abnormality occurrence of a diagnostic oil-filled transformer based on a temperature rise value during operation calculated by the arithmetic processing means, and information simulated by the simulation means are displayed. An oil-immersed transformer remaining life / abnormality diagnosis system comprising: display means; and output means for outputting simulation information displayed by the display means. Prototype oil-immersed transformer with operating conditions such as the temperature of the insulation cylinder surrounding the switching switch operating mechanism of the winding, lead conductor, load tap changer, etc. Measured data creation means of an oil-filled transformer that creates data files by actually measuring over time according to a predetermined load factor, and load current and cooling medium temperature indicating the operating state of the diagnosed oil-filled transformer, or Based on the operation status detection means of the diagnosed oil-filled transformer that detects either load current or ambient temperature over time and the operation status detected by the operation status detection means, actual measurement data creation of the oil-filled transformer An arithmetic processing means for calculating a temperature rise value at the time of operation of the diagnostic oil-filled transformer based on a temperature rise value calculation formula devised based on data accumulated in the means, and calculated by the arithmetic processing means operation Simulation means for simulating life loss / abnormality generation of the oil-filled transformer to be diagnosed based on the temperature rise value in the display, display means for displaying information simulated by the simulation means, and output of simulation information displayed by the display means And a remaining life / abnormality diagnosis system for an oil-filled transformer, comprising:   The remaining life / abnormality of an oil-filled transformer according to claim 1, wherein the load current is a current on the secondary side of the oil-filled transformer to be diagnosed, or a current on the primary side and connection tap information. Diagnostic system. Prototype oil-immersed transformer with operating conditions such as the temperature of the insulation cylinder surrounding the switching switch operating mechanism of the winding, lead conductor, load tap changer, etc. The measurement data creation means of the oil-filled transformer that creates data files by actually measuring over time according to a predetermined load factor, and the part that contributes to the remaining life and abnormality judgment during the operation of the diagnosed oil-filled transformer Based on the operating status detected by the operating status detecting means and the operating status detected by the operating status detecting means, the actual condition of the oil-filled transformer is detected. An arithmetic processing means for calculating a temperature rise value during operation of the diagnostic oil-filled transformer based on a temperature rise value calculation formula devised based on data accumulated in the data creating means; and Based on the calculated temperature rise value during operation, simulation means for simulating life loss / abnormality generation of the oil-in-transformer to be diagnosed, display means for displaying information simulated by the simulation means, and display by the display means An oil-immersed transformer remaining life / abnormality diagnosis system, characterized by comprising output means for outputting simulation information. Prototype oil-immersed transformer with operating conditions such as the temperature of the insulation cylinder surrounding the switching switch operating mechanism of the winding, lead conductor, load tap changer, etc. The measurement data creation means of the oil-filled transformer that creates data files by actually measuring over time according to a predetermined load factor, and the part that contributes to the remaining life and abnormality judgment during the operation of the diagnosed oil-filled transformer The operating condition detection means of the oil-in-transformer to be diagnosed having the function of simulating the temperature of the part to be performed assuming that the load fluctuation and the ambient temperature fluctuate, and the operating condition detected by the operating condition detection means Based on the calculation formula for the temperature rise value based on the data accumulated in the actual measurement data creation means of the oil-filled transformer, the temperature rise value during operation of the diagnosed oil-filled transformer is calculated based on An arithmetic processing means, a simulation means for simulating a life loss / abnormality occurrence of the diagnostic oil-filled transformer based on the temperature rise value during operation calculated by the arithmetic processing means, and information simulated by the simulation means are displayed. An oil-immersed transformer remaining life / abnormality diagnosis system comprising: display means; and output means for outputting simulation information displayed by the display means. The calculation formula of the temperature rise value in each part of the diagnosed oil-filled transformer calculated by the calculation processing by the calculation processing means is devised based on the actual measurement data actually measured by the prototype oil-filled transformer. The residual life / abnormality diagnosis system for an oil-filled transformer according to claim 1, 4, 5, 7, or 8, characterized in that:
[Equation 10]
Tc = (Tm−Tn) × exp ^{(−t / τ 2)} + Tn− (Tm × exp ^{(−t / τ 1)} )
However,
Tm: Maximum temperature increase value (° C.) of each part from the maximum oil temperature of the diagnostic oil-filled transformer immediately after the rated current is applied.
Tn: Temperature rise value (° C.) of each part from the maximum oil temperature of the oil-in-transformer to be diagnosed during continuous energization of the rated current.
t: energization time (a value indicating how much time has passed since the calculation start time is 0).
τ1: Time constant when the temperature from the maximum oil temperature suddenly increases in each part of the oil-filled transformer to be diagnosed immediately after the rated current is applied.
τ2: Time constant from when the temperature from the maximum oil temperature reaches the maximum value at each part of the oil-filled transformer to be diagnosed immediately after the rated current is applied until the value reaches a constant value.

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