JP5562287B2 - Remaining life diagnosis method and remaining life diagnosis device for power distribution equipment - Google Patents

Description

  The present invention relates to a method and apparatus for diagnosing the remaining life of a power receiving / distributing device. More specifically, the present invention relates to a technique for accurately diagnosing a remaining life due to a decrease in insulation resistance of a solid insulator used in a power receiving / distributing device in operation.

  The power distribution facility is a facility responsible for supplying electrical energy to factories and buildings. Power distribution facilities are required to operate with reliability and stability. If the insulation used in the power distribution equipment deteriorates due to the long-term use of the power distribution equipment, and an electrical trouble occurs as a result, the production equipment or building, such as loss in production or repair of the equipment, will be The effect will increase. For this reason, the technique for diagnosing degradation of the insulator used for power distribution equipment with high accuracy is desired.

  In general, the deterioration process of the insulator in the power distribution facility is considered as follows. (1) The resistance of the insulator surface decreases. (2) Due to Joule heat due to leakage current, a local dry zone is formed in the insulator. (3) Scintillation discharge is generated by voltage concentration on the dry zone. (4) Occurrence of dielectric breakdown due to carbonization of organic matter (formation of carbonized conductive paths) by discharge.

  Conventionally, as a method for diagnosing deterioration of an insulator, a method of measuring an insulation resistance or a method of measuring a partial discharge has been mainly performed. However, measured values of insulation resistance or measured values of partial discharge can vary greatly depending on humidity. Therefore, it cannot be said that the diagnostic accuracy is sufficient. In order to prevent electrical troubles in advance and to reduce maintenance costs by optimizing the maintenance cycle, it is important to diagnose the remaining insulation life in consideration of humidity conditions.

  For this reason, a method for diagnosing the remaining life of an insulator in consideration of humidity conditions has been proposed. For example, a method for obtaining an insulation lifetime based on a correlation between insulation characteristics and humidity has been proposed (see, for example, Patent Document 1). Alternatively, a method has been proposed in which a change in surface resistivity of an insulator is monitored by attaching a comb electrode to the insulator and measuring leakage current, and the deterioration of the insulator is diagnosed from the monitoring result (for example, Patent Documents). 2).

  Specifically, Patent Document 1 discloses the following method for estimating the remaining lifetime of an insulator. That is, an initial characteristic curve and a limit characteristic curve are input to the system as a reference curve for life estimation. The initial characteristic curve is based on the correlation between the initial insulation characteristic of the motor insulator and the relative humidity. The limit characteristic curve is based on the correlation between the insulation characteristic at the limit and the relative humidity. The system calculates the current characteristic curve based on the reference curve. This current characteristic curve is a curve that passes through a characteristic point determined by the insulation characteristic of the electric motor to be an insulation life estimation target and the relative humidity of the electric motor. The system estimates the insulation life of the target motor based on the current characteristic curve, the age of the target motor, and the contamination rate of the target motor.

  Patent Document 2 discloses the following method for estimating the remaining insulation life. That is, an insulation diagnostic sensor is attached to the power distribution facility. This sensor is made of a material equivalent to a solid insulating material used for a main circuit portion constituting the above power receiving and distributing equipment. The sensor has a degrading part that has been intentionally deteriorated and an undegraded part that has not been deteriorated, and the deteriorated part and the non-deteriorating part are provided with comb-shaped electrodes for measuring the surface electrical resistivity. Changes in the surface electrical resistivity of both parts are measured, and the remaining life of the power receiving and distributing equipment is calculated based on the reference curve representing the time dependence of the surface electrical resistivity and the change in the surface electrical resistivity.

JP 2004-177383 A JP 2002-372561 A

  The deterioration of the insulator at the site where the power distribution equipment is actually installed is affected by NOx (nitrogen oxide), SOx (sulfur oxide), dust or contaminants in the atmosphere. Therefore, the actual deterioration of the insulator proceeds while various deterioration modes change in a complicated manner.

  In the method for diagnosing the remaining insulation life described in Patent Document 1, the possibility that the humidity dependency of the insulation characteristics changes depending on the type or relative amount of the ionic substance adhering to the insulator is not considered. In the method described in Patent Document 1, the relationship between humidity and insulation resistance is created using a motor that has been forcibly deteriorated in insulation. The relationship between humidity and insulation resistance is created, for example, by changing the humidity conditions in the environmental laboratory. Alternatively, the relationship between humidity and insulation resistance in a wide humidity range is created by changing the measurement date using an electric motor in a specific field. Alternatively, a specific electric motor is picked up from the field, and the relationship between humidity and insulation resistance is created by an environmental laboratory or the like.

  On the other hand, in the method described in Patent Document 2, similarly to the method described in Patent Document 1, a correlation between humidity and insulation resistance is created by an accelerated test of the sample. Therefore, factors such as environmental differences or environmental changes at the installation site of the equipment are not reflected in the above correlation. For this reason, the method described in Patent Document 2 also has a problem in terms of detection accuracy of deterioration of the insulator.

  In the actual environment, humidity is changing. The resistance decreases as the humidity increases, while the resistance increases as the humidity decreases. However, as shown in FIG. 3 of Patent Document 1, according to the method of Patent Document 1, the same life is required regardless of the humidity at which the electric motor is used. In other words, the method of Patent Document 1 cannot present a remaining life corresponding to humidity. For this reason, the method of Patent Document 1 has a problem that it is difficult to make a facility operation and an update plan in consideration of risks.

  On the other hand, in the method of Patent Document 2, it is necessary to measure the surface resistivity of the sensor at a predetermined humidity after the sensor is installed in the power receiving and distributing device for a certain period. That is, in the method of Patent Document 2, the sensor installed in the power receiving / distributing device must be collected, and the surface resistivity of the sensor must be measured in an environmental laboratory or the like set to a predetermined humidity. For this reason, according to the method of patent document 2, there exists a problem that the remaining life diagnosis cannot be implemented in real time.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a remaining life diagnosis method and apparatus capable of accurately diagnosing the remaining life of a solid insulator of a power receiving / distributing device online. And

  A method for diagnosing the remaining life of a power receiving / distributing device according to an aspect of the present invention is a method for diagnosing the remaining life of a power receiving / distributing device including an insulator, and by using a surface resistivity evaluation technique that does not affect humidity, Obtaining a surface resistivity independent of the humidity of the insulation to be diagnosed included in the device, installing a sensor insulator made of the same or equivalent material as the insulation to be diagnosed on the power receiving and distributing device, Determining a conversion factor between the humidity independent surface resistivity and the surface resistivity of the sensor insulator; sequentially measuring the surface resistivity of the sensor insulator; and the measured surface resistivity of the sensor insulator Sequentially converting the surface resistivity of the insulator to be diagnosed using the conversion factor, the surface resistivity of the insulator to be diagnosed obtained by the converting step, and the use of the insulator to be diagnosed. Steps for sequentially obtaining the correlation between the years, the surface resistivity of the insulator to be diagnosed when the sensor insulator is installed, the surface resistivity independent of humidity, and the humidity and surface resistance obtained from the correlation From the predetermined relationship between the rates, the step of determining the humidity at which the correlation is obtained and the correlation from the determined humidity and the predetermined relationship between the humidity and surface resistivity thresholds And determining the remaining life of the power receiving and distributing device based on the difference between the number of years of use determined from the correlation and the threshold corresponding to the current number of years of use.

  A remaining life diagnosis device for a power receiving and distributing device according to another aspect of the present invention is a remaining life diagnostic device for a power receiving and distributing device including an insulator, which is installed in the power receiving and distributing device and is the same as or equivalent to the insulator to be diagnosed. The surface resistivity acquisition unit that sequentially acquires the surface resistivity of the sensor insulator made of the above material, and the surface resistivity of the sensor insulator is converted into the surface resistivity of the insulator to be diagnosed using a conversion factor acquired in advance. A surface resistivity conversion unit that sequentially converts, a correlation calculation unit that sequentially obtains a correlation between the surface resistivity of the insulator to be diagnosed and the age of use of the insulator to be diagnosed, and a threshold value corresponding to the correlation A threshold calculation unit for determining, and a remaining life calculation unit for determining the remaining life of the power receiving and distributing device based on a difference between the number of years of life determined from the correlation and the threshold and the current number of years of use. The conversion factor is obtained by using the surface resistivity evaluation technology that does not affect humidity, the surface resistivity of the sensor insulator when the sensor insulator is installed. It is a coefficient for converting into the surface resistivity independent of humidity. The threshold calculation unit is obtained in advance from the correlation between the surface resistivity of the insulator to be diagnosed when the sensor insulator is installed, the surface resistivity independent of humidity, and the humidity and surface resistivity. From this relationship, the humidity at which the correlation is obtained is determined. The threshold value calculation unit determines a threshold value corresponding to the correlation from the determined humidity and a previously determined relationship between the humidity and the threshold value of the surface resistivity.

  ADVANTAGE OF THE INVENTION According to this invention, the remaining life of the insulator with which an electric power distribution apparatus is equipped can be diagnosed on-line accurately.

It is the figure which showed the general view of the circuit breaker used for a power receiving / distributing apparatus. It is a general-view figure of a mold frame. It is a flowchart for demonstrating the remaining life diagnosis method of the power distribution equipment which concerns on this Embodiment. It is the top view which showed the sensor. It is a conceptual diagram for demonstrating replacement of surface resistivity. It is the figure which showed the result of having evaluated the relationship between a service life and surface resistivity using 1500 insulators used on the market. It is a figure explaining the method of calculating | requiring the remaining life of a power receiving / distributing apparatus. It is a figure for demonstrating the method of calculating | requiring the remaining lifetime of a power receiving / distributing apparatus depending on the humidity of an installation environment. It is a figure for demonstrating the method for calculating humidity from a correlation straight line. It is the figure which illustrated the humidity-surface resistivity characteristic memorized by the database. It is a figure for demonstrating the method for determining the threshold value of the surface resistivity in humidity 90% RH. It is a schematic block diagram of the system which performs the remaining life diagnostic method which concerns on embodiment of this invention. It is a functional block diagram of the control part shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

[Embodiment 1]
The remaining life diagnosis method for a power receiving / distributing device according to Embodiment 1 is a remaining life diagnosis method for obtaining the remaining life of a power receiving / distributing device including an insulator. The power receiving / distributing device includes, for example, main circuit components such as a circuit breaker, a disconnector, a busbar / conductor, and a measuring device. An example of the configuration of the power receiving / distributing device will be described below, but the present invention is not limited to this configuration.

  FIG. 1 is a diagram showing an overview of a circuit breaker used in a power receiving and distributing device. Referring to FIG. 1, blocking portions 51, 52, and 53 are installed corresponding to the three AC phases, respectively. Each of the blocking portions 51 to 53 is supported by a mold frame 54. FIG. 2 is an overview of the mold frame. Referring to FIGS. 1 and 2, the mold frame 54 is formed of, for example, a phenol insulator. FIG. 2 shows the dimensions of the mold frame 54, but these dimensions are merely examples and do not limit the present invention.

  Next, a method for diagnosing the remaining life of a power receiving / distributing device according to Embodiment 1 will be described. FIG. 3 is a flowchart for explaining a method for diagnosing the remaining life of power receiving and distributing equipment according to the present embodiment. Referring to FIG. 3, first, the surface resistivity of the diagnosis target insulator included in the power receiving / distributing device is grasped by a technique that does not affect humidity (step S <b> 1). The insulator to be diagnosed is an insulator that is to be diagnosed for insulation deterioration among insulators provided in the power receiving / distributing device, for example, an insulator that has a great influence on the life of the power receiving / distributing device due to severe insulation deterioration. An example of such an insulator is the mold frame described above.

  For example, a method described in Japanese Patent No. 3923257 or a method described in Japanese Patent No. 412430 can be applied as a method for grasping the surface resistivity of an insulator that does not affect humidity. The outline of these methods will be described. An ion test paper immersed in pure water is brought into contact with an insulator to be diagnosed, and an ion amount or color is measured from a change in the color of the ion test paper. By analyzing these data by a method such as the Mahalanobis Taguchi system method, the data is represented by one index. The relationship between the index and the surface resistivity is acquired in advance, and the surface resistivity of the insulator to be diagnosed is obtained based on the relationship and the index representing the data. Since the ion amount and color do not change with humidity, a surface resistivity that is not affected by humidity can be obtained. In addition, if the surface resistivity which is not influenced by humidity can be obtained, the method for that is not specifically limited, Arbitrary methods are applicable.

  Further, the insulator to be diagnosed may be specified in advance. Alternatively, the surface resistivity of each of the plurality of insulators included in the power receiving and distributing device may be obtained, and the insulator having the lowest surface resistivity may be determined as the insulator to be diagnosed. The number of insulators to be diagnosed may be plural.

  In step S2, a sensor is installed in the power receiving / distributing device (step S2). The sensor includes an insulator, and the insulator is made of the same or equivalent material as the insulator to be diagnosed. In general, the insulator is composed of a resin, a filler, a filler, an additive, and the like. “Equivalent” means, for example, that the constituent elements of two insulators are the same as each other, and when the constituent ratios of the two insulators are compared, the difference in constituent ratios for the same elements is within ± 10%. It means that. The position where the sensor 10 is installed is preferably as close as possible to the insulator to be diagnosed within a range that does not affect the function of the power receiving and distributing device.

  FIG. 4 is a plan view showing the sensor. Referring to FIG. 4, sensor 10 includes an insulator 1 and a pair of comb-shaped electrodes 2a and 2b. The material of the insulator 1 is the same as or equivalent to the material of the insulator included in the power receiving / distributing device, and examples thereof include unsaturated polyester resins, epoxy resins, and phenol resins. In the present embodiment, the material of the insulator 1 is an unsaturated polyester insulator containing an additive such as calcium carbonate and glass fiber.

  The comb electrodes 2 a and 2 b are disposed on the surface of the insulator 1. The material of the comb electrodes 2a and 2b may be any material as long as it exhibits conductivity, and more preferably can withstand corrosion caused by long-term use. In the present embodiment, the comb electrodes 2a and 2b are made of SUS.

  The unit of the dimensions shown in FIG. 4 is mm. The interval between the comb-shaped electrodes 2a and 2b is, for example, 1.0 to 5.0 mm. In the present embodiment, the width of each of the comb-shaped electrodes 2a and 2b (the length in the horizontal direction on the paper surface) and the distance between the comb-shaped electrodes 2a and 2b (the creeping distance 3) are both 2.0 mm. The length of the electrode portion extending in the horizontal direction in FIG. 3 is set to 1970 mm. However, in FIG. 3, the part of length 100mm is shown among the whole electrodes (1970 mm). For example, a voltage of 200 V is applied to this electrode, and the leakage current between the comb electrodes 2a and 2b is measured by a leakage ammeter. Thereby, the surface resistivity of the insulator 1 of the sensor 10 is obtained. Hereinafter, the insulator 1 of the sensor 10 is also referred to as “sensor insulator” in order to distinguish it from the insulator of the power receiving and distributing device.

  Returning to FIG. 3, in step S3, the surface resistivity of the sensor insulator is replaced with the surface resistivity of the insulator to be diagnosed to obtain the surface resistivity at the time of installation of the sensor insulator. Hereinafter, the replacement of the surface resistivity with the surface resistivity of the insulator to be diagnosed is also referred to as “surface resistivity conversion”.

  The sensor insulator is new. On the other hand, when installing a sensor insulator, the insulator to be diagnosed is often already used. Therefore, even if the material of the sensor insulator is the same as or equivalent to the material of the insulator to be diagnosed, the surface resistivity when the sensor insulator is installed is between the sensor insulator and the insulator to be diagnosed. Can be different. For this reason, conversion of surface resistivity is required.

FIG. 5 is a conceptual diagram for explaining the replacement of the surface resistivity. Referring to FIG. 5, for example, it is assumed that the surface resistivity of the insulator to be diagnosed is 10 ¹² Ω and the surface resistivity of the sensor insulator is 10 ¹⁵ Ω. In this case, by multiplying the surface resistivity of the sensor insulator by 1/1000 times (10 ⁻³ times), the surface resistivity of the sensor insulator at the time of installation of the sensor insulator is changed to the surface resistivity of the insulator to be diagnosed. To the same value, ie 10 ¹² Ω. Thereafter, the surface resistivity is converted by multiplying the surface resistivity calculated based on the leakage current of the sensor insulator by 1/1000. That is, conversion from the surface resistivity of the sensor insulator to the surface resistivity of the insulator to be diagnosed is performed.

  FIG. 6 is a diagram showing the results of evaluating the relationship between the years of use and the surface resistivity using 1500 insulators used in the market. Referring to FIG. 6, the vertical axis of the graph is a logarithmic axis for representing the surface resistivity of the insulator at a humidity of 50% RH (RH: relative humidity). The horizontal axis of the graph is a linear axis for representing the age of the insulator. The graph plots the average value of the surface resistivity against the service life.

  The surface resistivity data may include errors due to environmental factors such as NOx. However, the number of samples is about 1500, and this number of samples is considered to be sufficient to grasp the aging tendency of the surface resistivity.

  The main deterioration factor of the insulator of the power distribution device is an environmental factor such as NOx or sea salt as described above. Therefore, even if the operating conditions such as the operating voltage are different between the power receiving / distributing device and the sensor 10, the deterioration of the sensor insulator and the deterioration of the insulating material of the power receiving / distributing device are the same as long as the surrounding environment is the same. To progress.

  FIG. 6 shows that the linear value of the age of use and the logarithmic value of the surface resistivity have a linear relationship. Since the slope of the straight line is constant, the logarithmic value of the surface resistivity changes on the same straight line (the straight line shown in FIG. 6) according to the years of use. The deterioration of the sensor insulator proceeds in the same manner as the deterioration of the insulator of the power receiving / distributing device. Therefore, the surface resistivity of the insulator to be diagnosed can be obtained by multiplying the measured surface resistivity of the sensor insulator by a certain coefficient (in the above case, 1/1000).

  Returning to FIG. 3 again, in step S4, the surface resistivity of the sensor insulator is sequentially measured, and conversion is sequentially performed on the measured value. This measurement and conversion are performed at a predetermined cycle, for example, every hour from the start of use of the sensor insulator. Thereby, the surface resistivity of the sensor insulator is sequentially converted into the surface resistivity of the insulator to be diagnosed.

  Next, in step S5, a correlation between the surface resistivity calculated in step S4 and the age of use of the insulator to be diagnosed is sequentially obtained. The correlation is obtained using, for example, the least square method. Each time measurement and conversion are performed by the process of step S4, a correlation between the years of use and the surface resistivity is obtained. The service life of the insulation subject to diagnosis is the service life of the power distribution equipment.

  Subsequently, the remaining life of the power receiving / distributing device is obtained based on the correlation between the years of use and the surface resistivity obtained in step S5 (steps S6 and S7).

  FIG. 7 is a diagram illustrating a method for obtaining the remaining life of the power receiving / distributing device. Referring to FIG. 7, the points in the graph are points in which the surface resistivity of the insulator to be diagnosed calculated in step S <b> 4 is plotted against the years of use of the insulator to be diagnosed. The correlation straight line 11 in the graph is a straight line representing the correlation function obtained by the process of step S5. In step S <b> 6, based on the correlation line 11, the life years corresponding to the predetermined threshold D of the surface resistivity are calculated. The remaining life of the power receiving / distributing device is obtained based on the difference between the life years and the service life B up to now. In addition, A is the surface resistivity on the correlation straight line 11 corresponding to the current service life.

The life years C is the years of service corresponding to the intersection of the correlation line 11 and the straight line 12 indicating the predetermined threshold D of the surface resistivity. The predetermined threshold D of the surface resistivity is set in advance to, for example, the highest value of the surface resistivity at which discharge occurs at a predetermined humidity. In the example of FIG. 7, in the present embodiment, the predetermined threshold D of the surface resistivity is set to 10 ⁹ Ω / □. In the example of FIG. 7, the lifetime C is 33 years. The number of years (3 years) obtained by subtracting the number of years of use B at the time of remaining life diagnosis (30 years in the example of FIG. 7) from the life years C (33 years) is regarded as the remaining life of the power receiving / distributing equipment.

  Here, the correlation line obtained by the process of step S5 is considered to be a relationship between the surface resistivity at the average humidity in the installation environment and the years of use. By the process of step S5, the remaining life of the power receiving and distributing device at the average humidity in the installation environment can be obtained.

  According to the remaining life diagnosis method for power receiving / distributing equipment comprising the above steps, the correlation (correlation straight line) between the years of use and the surface resistivity is successively updated by the processes of steps S4 and S5. According to this method, the difference in the environment at the installation site or the change in the environment is reflected in the correlation line, so that the deterioration of the insulator can be accurately detected. Thereby, the remaining life of the insulator to be diagnosed (the insulator provided in the power receiving / distributing device) can be diagnosed with high accuracy. As a result, it is possible to prevent electrical trouble that may occur due to deterioration of the insulator provided in the power receiving and distributing device.

  The method described above is a method for diagnosing the remaining life when the humidity in the installation environment is the average humidity. Next, a remaining life diagnosis method when the humidity in the installation environment is an arbitrary humidity other than the average humidity (for example, humidity 90% RH) will be described.

  FIG. 8 is a diagram for explaining a method of obtaining the remaining life of the power receiving / distributing device depending on the humidity of the installation environment. Similar to FIG. 7, FIG. 8 shows a correlation line 13 representing the correlation between the years of use and the surface resistivity of the insulator to be diagnosed. However, the predetermined threshold D of the surface resistivity is changed according to the humidity assumed for the remaining life. Each of X and Y shown in FIG. 8 corresponds to a predetermined threshold value of the surface resistivity assumed for the remaining life. X (Ω / □) is a threshold value at an average humidity (for example, 50% RH) in the installation environment, and Y (Ω / □) is a threshold value at a humidity of 90% RH.

  In order to obtain the remaining life at a humidity of 90% RH, first, the life years G are obtained. The life years G is the number of years of use corresponding to the intersection of the correlation line 13 and a straight line representing a predetermined threshold value Y (Ω / □) of the surface resistivity. Next, the service life E at the time of remaining life diagnosis is subtracted from the service life G. Thus, the remaining life of the power receiving / distributing device is required.

  A method for changing the predetermined threshold value of the surface resistivity according to the humidity assumed for the remaining lifetime will be described. First, it is assumed that the surface resistivity (surface resistivity independent of humidity) of the insulator to be diagnosed obtained in step S1 is the surface resistivity at the average humidity (humidity 50RH%).

As shown in FIG. 9, for example, in a service life of 10 years (equal to the installation time of the sensor 10), the surface resistivity of the insulator independent of humidity is determined to be 10 ¹² (Ω / □). The correlation line 14 shows the correlation between the years of use and the surface resistivity obtained in step S5. From the correlation line 14, the surface resistivity at the installation time of the sensor 10 (10 years of use) is determined to be 5 × 10 ¹⁰ (Ω / □). The difference in surface resistivity at the time of sensor installation is considered to be due to the influence of humidity. The humidity-surface resistivity characteristics stored in the database are referred to using the type and amount of ions attached to the insulator to be diagnosed measured in step S1.

FIG. 10 is a diagram illustrating the humidity-surface resistivity characteristics stored in the database. Referring to FIG. 10, the horizontal axis of the graph indicates relative humidity, and the vertical axis of the graph indicates surface resistivity. The surface resistivity (in other words, the surface resistivity independent of humidity) when the relative humidity is 50% RH (average humidity) is 10 ¹² (Ω / □). According to this curve, the relative humidity when the surface resistivity at the sensor installation time is 5 × 10 ¹⁰ (Ω / □) is determined to be 60% RH.

  FIG. 11 is a diagram for explaining a method for determining a threshold value of surface resistivity at a humidity of 90% RH. Referring to FIG. 11, the humidity-surface resistance characteristic characteristic for determining the threshold value is referred to using the kind and amount of attached ions of the insulator to be diagnosed measured in step S <b> 1.

First, a predetermined threshold value of the surface resistivity at a humidity of 90% is determined in advance. In this embodiment, the predetermined threshold value of the surface resistivity at a humidity of 90% is 10 ⁹ (Ω / □). On the other hand, the correlation line 14 shown in FIG. 9 represents the correlation between the surface resistivity at 60% humidity and the years of use. From the characteristics shown in FIG. 11, when the surface resistivity at a humidity of 90% RH is 10 ⁹ (Ω / □), the surface resistivity at a humidity of 60% RH is 10 ¹⁰ (Ω / □). ) Is required. Therefore, the threshold value to be compared with the correlation line 14 is set to a threshold value at 60% humidity, that is, 10 ¹⁰ (Ω / □).

  As described above, in step S6, the humidity corresponding to the correlation line and the threshold value corresponding to the humidity are determined. In step S7, the service life corresponding to the intersection of the straight line representing the threshold and the correlation line 14 is determined as the life time. Then, the difference between the life years and the years of use up to the present is calculated as the remaining life.

  Thus, in the present embodiment, the predetermined threshold value of the surface resistivity is changed according to the humidity assumed for the remaining life. Thereby, the threshold value of the surface resistivity corresponding to the case where the humidity increases and the surface resistivity decreases can be obtained. By changing the threshold value in this way, it is possible to improve the accuracy of the remaining life of the power receiving / distributing device, so that it is possible to make a facility operation plan or a facility renewal plan in consideration of risks.

  FIG. 12 is a schematic configuration diagram of a system that executes the remaining life diagnosis method according to the embodiment of the present invention. Referring to FIG. 12, remaining life diagnosis apparatus 100 is realized in the form of a control board whose operation is controlled by a program recorded on a recording medium such as a magnetic disk. However, the control board is an example of the remaining life diagnosis apparatus 100, and the hardware configuration of the remaining life diagnosis apparatus 100 is not particularly limited.

  The remaining life diagnosis apparatus 100 includes an input unit 101, a storage unit 102, a control unit 103, and an output unit 104.

  The input unit 101 includes an input device such as a keyboard and a mouse or a tablet. The input unit 101 receives input of various data necessary for diagnosing the remaining life of the diagnosis target insulator 55 and sends the input data to the storage unit 102. For example, humidity-surface resistivity characteristics data is input prior to the remaining life diagnosis. A predetermined voltage (for example, 200 V) is applied to the sensor 10 by the measuring instrument 20, and the leakage current flowing through the sensor 10 is measured by the measuring instrument 20. The value of the leakage current sent from the measuring device 20 is input to the input unit 101. Further, measurement data of the type and amount of ions attached to the insulator to be diagnosed is also input to the input unit 101.

  The storage unit 102 is a memory device including, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, and the like, a program for performing a remaining life diagnosis method, humidity-surface resistivity characteristics (FIG. 10, 11) and various data such as data relating to the sensor 10 for calculating the surface resistivity from the leakage current value (for example, the lengths, widths, and pitches of the comb-shaped electrodes 2a and 2b) are stored. In addition, the storage unit 102 stores various data input to the input unit 101, for example, measurement data of the type and amount of ions adhering to the insulator to be diagnosed, and data of the leakage current value of the sensor 10. To do.

  The control unit 103 is realized by a microprocessor (MPU), for example, and reads a program stored in the storage unit 102, thereby executing processing related to the remaining life diagnosis according to the procedure described in the program. The output unit 104 outputs the remaining life diagnosis result by the control unit 103 to the external output device 105. For example, the output device 105 can include a printer, a display, or both.

  FIG. 13 is a functional block diagram of the control unit shown in FIG. Referring to FIG. 13, control unit 103 includes a surface resistivity calculation unit 111, a surface resistivity conversion unit 112, a correlation straight line calculation unit 113, a threshold value calculation unit 114, and a remaining life calculation unit 115.

  The surface resistivity calculation unit 111 acquires the surface resistivity independent of humidity using the value of the leakage current of the sensor 10 and data related to the sensor 10 (for example, the lengths, widths, and pitches of the comb electrodes 2a and 2b). That is, the surface resistivity calculation unit 111 executes the process of step S1. In step S <b> 1, the type and amount of ions attached to the insulator to be diagnosed are measured. These measurement results are input to the input unit 101 and stored in the storage unit 102.

  The surface resistivity conversion unit 112 converts the surface resistivity calculated by the surface resistivity calculation unit 111 into the surface resistivity of the insulator to be diagnosed using the conversion coefficient. That is, the surface resistivity conversion unit 112 executes the process of step S3.

  The surface resistivity calculator 111 sequentially receives the measurement result of the leakage current value of the sensor 10 and calculates the surface resistivity of the sensor insulator from the leakage current value. The surface resistivity conversion unit 112 sequentially converts the surface resistivity of the sensor insulator into the surface resistivity of the diagnosis target insulator using the conversion coefficient. That is, the surface resistivity calculation unit 111 and the surface resistivity conversion unit 112 also execute the process of step S4.

  The correlation straight line calculation unit 113 receives the surface resistivity value from the surface resistivity conversion unit 112 and reads the age of use from the storage unit 102. The correlation line calculation unit 113 sequentially calculates a correlation line indicating the correlation between the surface resistivity and the service life. That is, the correlation straight line calculation unit 113 executes the process of step S5.

  The threshold value calculation unit 114 executes the process of step S6. More specifically, the threshold value calculation unit 114 first determines a plurality of humidity-surface resistivity characteristics stored in the storage unit 102 (database) based on the type and amount of ions input in step S1. Select the optimum characteristics from As shown in FIG. 10, the threshold value calculation unit 114 determines the surface resistivity corresponding to the current service life based on the correlation line obtained by the correlation line calculation unit 113. Then, based on the selected humidity-surface resistivity characteristic, the humidity corresponding to the surface resistivity is determined.

  The storage unit 102 stores a plurality of humidity-surface resistivity characteristics for determining humidity from the surface resistivity on the correlation line. These multiple characteristics differ depending on the type and amount of ions. The threshold calculation unit 114 selects an optimum characteristic for determining humidity from a plurality of characteristics based on the type and amount of ions input in step S1.

  In this embodiment, the age of the insulator to be diagnosed when the sensor insulator is installed is 10 years. However, the years of use corresponding to the sensor installation time can vary. In this case, the humidity-surface resistivity characteristic selected based on the kind and amount of adhering ions may be corrected based on the surface resistivity independent of the humidity to be diagnosed. For example, the humidity-surface resistivity characteristic is corrected so that the surface resistivity at the average humidity (50% RH) matches the surface resistivity that does not depend on the humidity to be diagnosed.

  In addition, the number of types of ions attached to the insulator to be diagnosed is limited to some extent, but the amount of ions attached is considered to vary. Therefore, the storage unit 102 stores the number of humidity-surface resistivity characteristics corresponding to (number of types of ions) × (number of representative values of adhesion amount). The threshold value calculation unit 114 selects the characteristic of the closest condition from the plurality of humidity-surface resistivity characteristics based on the ion type and the adhesion amount input in step S1, and based on the ion adhesion amount. to correct.

  Next, the threshold value calculation unit 114 determines the threshold value of the surface resistivity from the humidity determined by the above processing. The storage unit stores a plurality of humidity-surface resistivity characteristics for determining the threshold value. These humidity-surface resistivity characteristics also differ depending on the type and amount of ions, as described above. The threshold value calculation unit 114 selects the characteristic under the closest condition from the plurality of humidity-surface resistivity characteristics based on the type of ions and the amount of adhesion input in step S1. Then, the threshold value calculation unit 114 determines the threshold value based on the selected humidity-surface resistivity characteristic and the humidity determined by the above processing.

  The remaining life calculation unit 115 calculates the lifetime of the insulator to be diagnosed based on the correlation line obtained by the correlation line calculation unit 113 and the threshold obtained by the threshold calculation unit 114. Next, the remaining life calculation unit 115 calculates the remaining life by subtracting the number of years of use up to the present from the life years. That is, the remaining life calculation unit 115 performs the process of step S7. The remaining life calculated by the remaining life calculation unit 115 is output to the output unit 104.

  As described above, according to the first embodiment, the correlation between the surface resistivity of the diagnosis target insulator converted from the surface resistivity of the sensor insulator and the age of the insulator is sequentially obtained. According to the first embodiment, the surface ratio of the sensor insulator is sequentially converted into the surface resistivity of the insulator to be diagnosed using the conversion coefficient, and the correlation is sequentially updated using the conversion result. The remaining life of the insulator provided in the power distribution device can be diagnosed online.

  Further, the sensor insulator is installed in the same environment as the insulator to be diagnosed. Thus, the surface ratio of the sensor insulator can be converted into the surface resistivity of the insulator to be diagnosed using the conversion coefficient obtained first, and the reliability of the converted surface resistivity value is also increased.

  Furthermore, the threshold value of the surface resistivity for determining the remaining life varies depending on the humidity. By obtaining the remaining life from the threshold value that changes depending on the humidity and the correlation between the surface resistivity and the service life, the remaining life of the insulator to be diagnosed can be diagnosed online and with high accuracy. As the remaining life diagnosis accuracy increases (the calculated remaining life accuracy increases), a plan for efficient facility operation or a plan for efficient facility renewal can be established. Therefore, electrical troubles due to deterioration of the insulator of the power distribution facility can be prevented in advance.

  Furthermore, according to the first embodiment, the remaining life can be diagnosed in consideration of the possibility that the humidity dependency of the insulation characteristics changes depending on the type or relative amount of the ionic substance adhering to the insulator. As a result, the remaining life diagnosis accuracy can be further enhanced.

  Furthermore, according to the first embodiment, since the remaining life can be evaluated with high accuracy, for example, when it can be determined that the previous equipment update cycle is shorter than necessary, the equipment update cycle is lengthened. be able to. In such a case, the life of the power receiving / distributing device can be extended.

[Embodiment 2]
In the first embodiment, a correlation straight line between the years of use and the surface resistivity is obtained using all of the acquired surface resistivity data. In the second embodiment, a correlation line is determined using data selected from the acquired surface resistivity data.

  The remaining life diagnosis method according to the second embodiment is the same as the remaining life diagnosis method according to the first embodiment except for the above points. Therefore, the configuration of the remaining life diagnosis apparatus according to the second embodiment is the same as that of the remaining life diagnosis apparatus according to the first embodiment.

  Referring to FIG. 7, in the second embodiment, data within 50%, preferably within 30%, more preferably within 10% from the surface resistivity with the lower surface resistivity obtained. The correlation between the surface resistivity and the years of use is successively obtained.

  As shown in FIG. 7, in the first embodiment, the lifetime is estimated using a correlation line, that is, an approximate line that approximates the relationship between the service life and the surface resistivity. Since the approximate line represents the average, the obtained remaining life is the average remaining life. Therefore, at the time of the life years determined by the correlation line, the insulator exceeding the actual life years exists with a half probability. As described above, the estimated life years are actually obtained by creating a correlation line using data within 50%, preferably within 30%, more preferably within 10% from the lowest surface resistivity. It is possible to reduce the possibility of exceeding the service life years. Therefore, for example, it is possible to take measures such as renewing the equipment before burning out.

  Further, according to the second embodiment, since a remaining life under a relatively high humidity condition with a past record is required, it is necessary to allow the risk of a humidity condition without a past record, but according to the record Equipment operation and renewal plans can be made.

  The embodiment disclosed this time must be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Insulator (sensor insulator), 2a, 2b Comb electrode, 3 Creepage distance, 10 Sensor, 11, 13, 14 Correlation straight line, 12 straight line (threshold), 20 Measuring instrument, 51-53 Shut off part, 54 Mold frame, 55 Insulator to be diagnosed, 100 Life diagnosing device, 101 input unit, 102 storage unit, 103 control unit, 104 output unit, 105 output unit, 111 surface resistivity calculation unit, 112 surface resistivity conversion unit, 113 correlation line calculation unit 114 threshold value calculation unit, 115 remaining life calculation unit.

Claims (10)

A method for diagnosing the remaining life of a power receiving and distributing device including an insulator,
By using a surface resistivity evaluation technique that does not affect humidity, obtaining a surface resistivity that does not depend on the humidity of the insulator to be diagnosed included in the power receiving and distributing device; and
Installing a sensor insulator made of the same or equivalent material as the insulator to be diagnosed in the power distribution device;
Obtaining a conversion factor between the humidity independent surface resistivity and the surface resistivity of the sensor insulator;
Sequentially measuring the surface resistivity of the sensor insulator;
Sequentially converting the measured surface resistivity of the sensor insulator into the surface resistivity of the diagnosis object insulator using the conversion factor;
Sequentially obtaining a correlation between the surface resistivity of the diagnosis target insulator obtained by the converting step and the service life of the diagnosis target insulator;
A predetermined relationship between the surface resistivity of the diagnostic object insulator at the time of installation of the sensor insulator, the surface resistivity independent of the humidity, and the humidity and the surface resistivity, which is obtained from the correlation. Determining the humidity at which the correlation is obtained;
Determining a threshold corresponding to the correlation from the determined humidity and a predetermined relationship between the humidity and surface resistivity thresholds;
A remaining life diagnosis method for a power receiving / distributing device, comprising: determining a remaining life of the power receiving / distributing device based on a difference between a service life determined from the correlation and the corresponding threshold and a current service life. Prepare a plurality of relationships between humidity and surface resistivity and a plurality of relationships between humidity and surface resistivity thresholds depending on the type and amount of ions that can adhere to the insulator to be diagnosed Steps,
Measuring the type and amount of ions attached to the insulator to be diagnosed, and
Determining the humidity comprises:
Selecting from among a plurality of relationships between humidity and surface resistivity a relationship depending on the type of ion measured and the amount deposited;
Determining the corresponding threshold value comprises:
The remaining life of the power receiving / distributing device according to claim 1, further comprising: selecting a relationship according to the measured ion type and adhesion amount from a plurality of relationships between humidity and a threshold value of surface resistivity. Diagnosis method.   3. The step of sequentially obtaining the correlation, wherein the correlation is sequentially obtained based on data within 50% from the lowest surface resistivity among the surface resistivity sequentially obtained by the converting step. The remaining life diagnosis method for the power distribution equipment described in 1.   4. The step of sequentially obtaining the correlation, the step of sequentially obtaining the correlation based on data within 30% from the lowest surface resistivity among the surface resistivity sequentially obtained by the converting step. The remaining life diagnosis method for the power distribution equipment described in 1.   5. The step of sequentially obtaining the correlation, wherein the correlation is sequentially obtained based on data within 10% from the lowest surface resistivity among the surface resistivity sequentially obtained by the converting step. The remaining life diagnosis method for the power distribution equipment described in 1. An apparatus for diagnosing the remaining life of power distribution equipment including an insulator,
A surface resistivity acquisition unit that is installed in the power distribution device and sequentially acquires the surface resistivity of the sensor insulator made of the same or equivalent material as the insulator to be diagnosed;
A surface resistivity conversion unit that sequentially converts the surface resistivity of the sensor insulator into the surface resistivity of the diagnosis object insulator using a conversion coefficient acquired in advance;
A correlation calculation unit that sequentially obtains a correlation between the surface resistivity of the insulator to be diagnosed and the age of use of the insulator to be diagnosed;
A threshold value calculation unit for determining a threshold value corresponding to the correlation;
A life expectancy determined from the correlation and the threshold, and a remaining life calculator that determines the remaining life of the power receiving and distributing device according to a difference between the current service life,
The conversion factor is obtained by using a surface resistivity evaluation technique that does not affect humidity, and the surface resistivity of the sensor insulator at the time of installation of the sensor insulator. It is a coefficient for converting to the surface resistivity independent of the humidity of the insulator to be diagnosed,
The threshold value calculation unit is obtained from the correlation, the surface resistivity of the insulator to be diagnosed at the time of installation of the sensor insulator, the surface resistivity independent of the humidity, the humidity and the surface resistivity The humidity at which the correlation is obtained is determined from a predetermined relationship between the predetermined humidity, and the correlation is determined from the determined humidity and the predetermined relationship between the humidity and the threshold value of the surface resistivity. An apparatus for diagnosing the remaining life of a receiving / distributing device that determines a threshold value. Stores a plurality of relationships between humidity and surface resistivity and a plurality of relationships between threshold values of humidity and surface resistivity according to the type and amount of ions that can adhere to the insulator to be diagnosed. A storage unit;
The threshold calculation unit includes:
From among a plurality of relationships between humidity and surface resistivity, determine the humidity at which the correlation is obtained by selecting a relationship according to the type and amount of ions attached to the insulator to be diagnosed, The corresponding threshold value is determined by selecting a relationship according to the type and amount of ions attached to the insulator to be diagnosed from among a plurality of relationships between the threshold values of humidity and surface resistivity. The remaining life diagnosis apparatus of the power receiving and distributing apparatus according to claim 6.   The said correlation calculation part calculates | requires the said correlation sequentially based on the data within 50% from the one where surface resistivity is low among the surface resistivity sequentially acquired by the said surface resistivity conversion part. The remaining life diagnosis device for power distribution equipment described in 1.   The said correlation calculation part calculates | requires the said correlation sequentially based on the data within 30% from the one where surface resistivity is low among the surface resistivity sequentially acquired by the said surface resistivity conversion part. The remaining life diagnosis device for power distribution equipment described in 1.   The correlation calculation unit sequentially obtains the correlation based on data within 10% from the lowest surface resistivity among the surface resistivity sequentially acquired by the surface resistivity conversion unit. The remaining life diagnosis device for power distribution equipment described in 1.

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