JP2020003277A - Method and system for diagnosing shorted residual life of power receiving/distributing apparatus - Google Patents

Abstract

To provide a method and system for diagnosing the shorted residual life of a power receiving/distributing apparatus, with which it is possible to accurately diagnose the shorted residual life of a power receiving/distributing apparatus equipped with an insulator.SOLUTION: Provided is a diagnosing method including: steps S1-S4 for calculating the surface resistivity of an insulator; a step S10 for deriving a first time dependency curve of the surface resistivity of the insulator due to an environment factor when the surface resistivity is larger than a discharge occurrence value; a step S12 for measuring humidity data and a partial discharge current in an environment where the insulator is installed and calculating a discharge occurrence time; and steps S13-S16 for calculating a nitrate ion adhering amount due to a discharge factor on the basis of the discharge occurrence time, deriving a second time dependency curve including a discharge factor pertaining to the surface resistivity of the insulator and calculating a shorted residual life. Also provided is a diagnosing system that includes means for executing each step.SELECTED DRAWING: Figure 1

Description

  This application is intended to grasp the situation of the deterioration of insulation performance due to the aging of the insulator used for power receiving and distribution equipment and the influence of the use environment. And a system for diagnosing remaining short-circuit life.

  Power receiving and distribution equipment is equipment provided with power receiving and distribution equipment for supplying electric energy to factories, buildings, and the like, and is required to operate with reliability and stability. If the insulator provided in the power receiving and distributing equipment is deteriorated due to long-term use and an electrical trouble occurs due to the deterioration of the insulation, it has a great effect on factories and buildings, such as production loss and equipment repair. On the other hand, the deterioration of the insulator is greatly affected by the installation environment (humidity, temperature, contaminated air such as gas, floating dust, etc.) of the power receiving / distributing device, so that the remaining life diagnosis is not easy. Therefore, there is a demand for an accurate diagnosis technique for the deterioration state of the insulation performance of the insulator provided in the power receiving and distribution device.

  The process of deterioration of an insulator generally includes (1) a decrease in resistance of the insulator surface due to attachment and generation of a deliquescent substance, (2) generation of a leakage current due to a decrease in resistance of the insulator surface, and (3) leakage current. (4) Partial discharge due to voltage concentration in the dry zone, (5) Dielectric breakdown due to the progress of carbonized conductive paths generated in organic matter due to discharge It is thought to occur in order.

  On the other hand, in order to prevent electrical troubles, optimize the maintenance cycle, and reduce maintenance costs, the degree of deterioration of the insulator must be quantitatively and accurately grasped before an electrical abnormality occurs. Therefore, it is desired to diagnose the remaining life of the power receiving and distribution equipment.

  On the other hand, as a method of diagnosing an insulator, the methods described in Patent Documents 1 to 3 have been implemented.

  In the method based on insulation resistance measurement described in Patent Literature 1, an initial characteristic curve based on a relationship between insulation characteristics and relative humidity at an initial time and a limit characteristic curve at a limit time are used as reference curves for life estimation, and a reference curve is used. By calculating the current characteristic curve passing through the characteristic points of the insulation characteristics and relative humidity of the target device based on the current characteristic curve, the number of years of use, and the remaining life of the insulator of the target device based on the contamination rate Estimated.

  In the method based on partial discharge measurement described in Patent Literature 2, the residual breakdown voltage is obtained by an arithmetic expression including a maximum discharge charge amount and a discharge parameter. Inspect the delamination state and chemical deterioration state inside the insulating layer, correct the maximum discharge charge and discharge parameters according to the inspection results, and calculate the residual breakdown voltage using the corrected maximum discharge charge and discharge parameters , The remaining life of the insulator of the target device is estimated.

  In the method based on ion, color, and humidity data described in Patent Document 3, the degree of deterioration of an insulator is estimated from the ion and color data, and the degree of deterioration and humidity data of the insulator obtained in advance and the deterioration due to discharge are obtained. The relationship between the insulation resistance characteristic curve and the number of years of use is determined from the development data, and the remaining short-circuit life of the insulator of the target device is estimated.

JP-A-2004-177383 JP-A-9-80029 WO2017 / 002728 / A1

On the other hand, the deterioration of the insulator at the site where the equipment is actually installed is affected by NOx, SOx, dust and contaminants in the atmosphere until the discharge occurs. Under the influence of the factors and the ozone and nitric acid generated by the discharge, the carbonized conductive path develops due to the discharge, leading to dielectric breakdown.
That is, the deterioration of the insulator progresses due to environmental factors and discharge factors, and the rate of deterioration increases after discharge occurs.

However, the method based on insulation resistance measurement described in Patent Literature 1 can cope only with deterioration due to environmental factors, so that there is a problem that insulation diagnosis cannot be performed when the deterioration speed changes from the occurrence of a discharge to a short circuit. .
Further, in the method based on the partial discharge measurement described in Patent Literature 2, the occurrence of discharge is targeted, but the occurrence of discharge is greatly affected by the humidity, and once the discharge is performed, the discharge may stop when the humidity decreases. Therefore, there is a problem that the diagnosis result varies, and further, there is a problem that it cannot be applied in a stage where no discharge occurs.

  Further, in order to realize the method described in Patent Document 3, a power outage operation for collecting various data such as the surface resistance value of the insulator of the electrical device to be diagnosed is required from the time of starting discharge to the time of dielectric breakdown. In order to detect abnormalities early, frequent power outage plans must be made. In addition, since the diagnosis is performed under certain environmental conditions (such as humidity) different from the normal operation state, there is a problem that the abnormality of the operation state is only indirectly diagnosed. Further, the discharge phenomenon occurs when the electric field intensity due to the application exceeds the discharge limit point (electric field strength at the start of partial discharge) at the abnormal location. This discharge limit point differs greatly depending on the state of the abnormal location. When a discharge occurs, the surrounding energy is destroyed by the discharge energy. At this time, the state of the abnormal portion changes, and the discharge limit point changes every moment. Therefore, even if a spot-like diagnosis at the time of a power failure is performed, it cannot be said that it is the same as during normal operation, and there is a problem that it is hard to say that the diagnosis accuracy is high in useful value (the diagnosis results vary widely).

  This application was made in order to solve the above problems, and to accurately diagnose the remaining short-circuit life (remaining time until a short circuit occurs in an insulator) of a power receiving and distribution device including an insulator. It is an object of the present invention to provide a method and a system for diagnosing remaining short-circuit life of a power receiving and distribution device.

  The method for diagnosing remaining short-circuit life of a power receiving / distributing device disclosed in this application is a method for diagnosing remaining short-circuit life of a power receiving / distributing device provided with an insulator, wherein the surface resistivity of the insulator is calculated. And when the surface resistivity is greater than a discharge occurrence value, a first time-dependent factor based on environmental factors relating to the surface resistivity of the insulator based on environmental factor data including a nitrate ion adhesion amount of the insulator. Deriving the property, calculating the discharge generation time based on the humidity data of the environment in which the insulator is installed and the partial discharge current measurement result, and calculating the nitrate ion adhesion amount due to a discharge factor based on the discharge generation time. Calculating a remaining short-circuit life by deriving a second time dependency of a surface resistivity of the insulator based on the nitrate ion adhesion amount due to a discharge factor and the environmental factor data. It is intended to include.

  The system for diagnosing remaining short-circuit life of a power receiving / distributing device disclosed in this application includes: a use condition of a power receiving / distributing device to be diagnosed; a parameter condition of an insulator of the power receiving / distributing device; A means for inputting an ion adhesion amount and a color parameter of the insulator; and a control means for diagnosing a remaining short-circuit life, wherein the control means discharges the insulator based on the input use conditions and parameter conditions. Means for calculating the surface resistivity to be generated, and means for calculating the surface resistivity of the insulator according to the measured amount of nitrate and sulfate ions attached to the insulator and the color parameter of the insulator. Means for judging whether or not the surface resistivity of the insulator is higher than the surface resistivity at which the discharge of the insulator occurs, and the insulator calculated by the judging means. If it is determined that the surface resistivity is higher than the surface resistivity at which the discharge of the insulator occurs, a means for deriving the time dependence of the amount of nitrate ion and sulfate ion attached to the insulator and the color parameter of the insulator. Means for deriving a first time dependency of the surface resistivity of the insulator due to environmental factors based on the derived time dependency, humidity data of the environment where the insulator is installed, and partial discharge current Means for measuring the discharge occurrence time by measuring the amount of nitrate ion due to discharge from the calculated discharge occurrence time, nitrate ion adhesion amount due to the calculated discharge factor and nitrate ion adhesion amount due to the environmental factor and A method for deriving a second time dependence of the surface resistivity of the insulator due to discharge factors and environmental factors based on the sulfate ion deposition amount and the color parameters of the insulator. If, comprising means for calculating a short remaining lifetime from the basis of the second time-dependent, the calculated insulator surface resistivity of the predetermined short-circuit threshold.

  According to the method for diagnosing remaining short-life of a power receiving and distributing device and the remaining short-circuit diagnosing system disclosed in this application, the amount of nitrate ion attached to an insulator due to a discharge factor is calculated by using a discharge current measurement result and humidity data, To calculate the remaining short-circuit life based on the environmental factor data including the nitrate ion adhesion amount and the nitrate ion adhesion amount due to the discharge factor, the insulation deterioration due to both the environmental factor and the discharge factor is considered. Can be accurately diagnosed.

FIG. 3 is a flowchart illustrating a method for diagnosing remaining short-circuit life of a power receiving and distribution device in the first embodiment. FIG. 2 is a diagram illustrating a correlation between a Mahalanobis distance and a surface resistivity according to the first embodiment. FIG. 3 is a perspective view for explaining an experimental apparatus for deriving a time dependency equation of the amount of attached nitrate ions according to the first embodiment. FIG. 3 is a diagram illustrating a time-dependent curve of a surface resistivity of an insulator included in a power receiving and distribution device due to environmental factors according to the first embodiment; FIG. 3 is a diagram illustrating a relationship between relative humidity (RH%) and surface resistivity according to the first embodiment. FIG. 2 is a block diagram illustrating a short-circuit acceleration test device according to the method for diagnosing remaining short-circuit life of a power receiving and distribution device in the first embodiment. FIG. 7 is a cross-sectional view showing a state of attachment of an insulator in a constant temperature / humidity chamber of the short-circuit acceleration test device shown in FIG. 6. FIG. 3 is a diagram illustrating a change over time in the amount of nitrate ions attached to an insulator due to discharge according to the first embodiment; FIG. 3 is a diagram illustrating a time-dependent curve of the surface resistivity of an insulator included in a power receiving and distribution device due to environmental factors and discharge factors according to the first embodiment; FIG. 10 is a diagram similar to FIG. 9, illustrating a time-dependent curve of the surface resistivity of an insulator included in a power receiving and distribution device due to environmental factors and discharge factors (discharge actual measurement is performed). FIG. 10 is a diagram similar to FIG. 9, illustrating a time-dependent curve of the surface resistivity of an insulator included in a power receiving and distribution device due to environmental factors and discharge factors (discharge actual measurement is performed). FIG. 2 is a schematic configuration diagram of a discharge detector and a diagnostic device according to the first embodiment. FIG. 3 is a schematic diagram of a processing flow of a discharge detection function part according to the first embodiment. FIG. 7 is a schematic configuration diagram illustrating a short-circuit remaining life diagnosis system of a power receiving and distribution device according to a second embodiment.

  Hereinafter, embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.

Embodiment 1 FIG.
Embodiment 1 will be described with reference to FIGS. The remaining short-circuit life diagnosis method according to the first embodiment is a method for diagnosing the remaining short-circuit life of a power receiving and distribution device provided with an insulator.
Here, the insulator to be diagnosed is an insulator (for example, a support of a main circuit to which a voltage is applied) included in the power receiving / distributing device, for which insulation deterioration is to be diagnosed, for example, progress of insulation deterioration. Is an insulator that is important for the life of power receiving and distribution equipment. Examples of insulators include, but are not limited to, unsaturated polyester insulators, phenol insulators, epoxy insulators, and the like.

FIG. 1 is a flowchart of a method for diagnosing remaining short-circuit life of a power receiving and distribution device according to the first embodiment.
First, the surface resistivity at which discharge and short-circuit of the insulator occur is obtained based on the use condition of the power receiving and distribution device to be diagnosed and the parameter condition of the insulator of the power receiving and distribution device (step S1).
Specifically, based on the rated voltage of the power receiving and distribution device to be diagnosed, the operating frequency and the thickness of the insulator included in the power receiving and distribution device, the creepage distance, and the permittivity, a predetermined predetermined value is used. The surface resistivity at which discharge occurs is obtained based on the arithmetic expression.

Next, environmental factor data including the nitrate ion attachment amount, the sulfate ion attachment amount, and the color data of the insulator of the power receiving and distribution device to be diagnosed is measured (step S2).
Then, a measurement result is obtained (step S3).
Table 1 below illustrates the measurement results of the nitrate ion attachment amount, the sulfate ion attachment amount, and the color data (also referred to as color parameters).

  Note that the items to be measured are not limited to nitrate ion and sulfate ion adhesion amounts and color data, but are required to determine the surface resistivity of an insulator without being affected by external noise such as humidity and electromagnetic waves. I just want it. Here, the color data indicates data obtained by measuring the insulator with a colorimeter or the like, and expressing the color of the insulator by numerical values in a color system such as RGB (RGB color model) or Lab (Lab color space).

Next, the surface resistivity of the insulator in the power receiving and distribution device to be diagnosed is calculated from the measurement results of the nitrate ion attachment amount, the sulfate ion attachment amount, and the color data acquired in step S3 (step S4).
As described above, a short circuit due to aging of the insulator of the power receiving and distribution device is caused by a decrease in the surface resistivity. Therefore, it is appropriate to obtain the surface resistivity as the degree of deterioration of the insulator.
In the first embodiment, the surface resistivity of the insulator of the power receiving / distributing device to be diagnosed is calculated from the nitrate ion attachment amount, the sulfate ion attachment amount, and the color data as follows.

FIG. 2 is a diagram illustrating the correlation between the Mahalanobis distance and the surface resistivity.
In FIG. 2, the vertical axis represents the surface resistivity, and the horizontal axis represents a correlation diagram using the distance of Mahalanobis from a reference based on the initial state of the insulator as an index of deterioration.
Specifically, the amount of nitrate ion and the amount of sulfate ion and the color data of the initial state of the insulator and the state after a predetermined time are measured in advance, and one index, book, which takes into account the dispersion and correlation of the measurement. In the first embodiment, the degree of deterioration of the insulator is represented by the Mahalanobis distance, and a predetermined correlation equation shown in, for example, Japanese Patent No. 412430 is calculated according to the correlation between the index and the measured value of the surface resistivity.

  Then, in the first embodiment, the distance of Mahalanobis, which is an index of deterioration, is obtained from the measured amounts of nitrate and sulfate ions and the color data of the insulator of the power receiving / distributing device that is the object of diagnosis, and FIG. The surface resistivity of the insulator of the power receiving / distributing device to be diagnosed is calculated based on the predetermined correlation equation described in Japanese Patent No. 412430.

Next, the surface resistivity at which discharge occurs for the insulator of the power receiving and distribution device to be diagnosed is compared with the surface resistivity calculated at step S4, and the surface resistivity calculated at step S4 indicates that discharge occurs. It is determined whether it is greater than the surface resistivity (step S5).
In step S5, if the surface resistivity is higher than the surface resistivity at which discharge occurs, the process proceeds to step S8.

If the calculated surface resistivity is larger than the surface resistivity at which discharge occurs, the ratio of sulfate ion to nitrate ion and color data is calculated (step S8).
Table 1 shows, as an example, the ratio of the sulfate ion adhesion amount and the color data to the measured nitrate ion adhesion amount of the insulator. The colors in Table 1 are the colors b * in the color data obtained by measuring the insulator with a colorimeter and expressing it in the CIE 1976 (L *, a *, b *) color space.
The recommended replacement time of the power receiving / distributing device is 25 to 30 years, and the result of environmental degradation over a long period of time is a measured value of the attached amount of nitrate ion and attached sulfate and the color data.

Therefore, it is expected that the ratio of these measurements due to environmental factors will not change during the years leading up to the short circuit. Therefore, it is considered that the time dependency of the nitrate ion adhesion amount due to environmental factors is the same as the time dependence of the sulfate ion adhesion amount and the time dependence of the color data.
That is, based on the calculated ratio, it is possible to calculate the sulfate ion adhesion amount and the time dependence of the color data due to environmental factors from the time dependence of the nitrate ion adhesion amount.

Next, a time dependency formula of the nitrate ion attachment amount and the sulfate ion attachment amount due to environmental factors and the color data is derived (step S9).
FIG. 3 is a perspective view illustrating an experimental apparatus for deriving a time-dependent equation for the amount of attached nitrate ions.

  FIG. 3 shows an experimental apparatus in which a new insulator 1a and nitric acid 2 contained in an appropriate container are put into a desiccator 3 and exposed at a temperature of 60 ° C. Then, the measurement result of the attached amount of nitrate ion after a certain time is analyzed by the reaction kinetics to derive a time-dependent equation shown in the following equation (1).

In the formula (1), t represents time (hr), f (t) represents nitrate ion attachment amount (mg / cm ² ) after t hours from the installation of the device, and A represents an apparent NOx concentration in the atmosphere.
By substituting the years of use of the power receiving / distributing device to be diagnosed and the actually measured values of the attached amount of nitrate ions into t and f (t) in the above equation (1), the power receiving / distributing device to be diagnosed is installed. The apparent atmospheric NOx concentration A of the environment can be determined.

Then, an equation obtained by substituting the obtained apparent NOx concentration A in the atmosphere into the above equation (1) is derived as a time-dependent equation of the amount of nitrate ion deposition due to environmental factors of the insulator of the power receiving and distribution equipment to be diagnosed. It is possible.
In addition, based on the time dependence of nitrate ion deposition due to environmental factors, the time dependence of sulfate ion deposition due to environmental factors is calculated using the ratio of sulfate ion deposition and color data to nitrate ion deposition calculated above. A time dependency equation of color data due to the equation and environmental factors is derived.
This makes it possible to diagnose the degree of deterioration of the insulator in which no discharge has occurred due to environmental factors affected by NOx, SOx, dust and contaminants in the atmosphere.

Referring to FIG. 1 again, next, a time dependency curve (first time dependency curve) 201 of the surface resistivity due to environmental factors is derived (step S10).
FIG. 4 is a diagram illustrating a time-dependent curve (first time-dependent curve) 201 of the surface resistivity of the insulator included in the power receiving and distribution device due to environmental factors.
The time-dependent curve 201 of the surface resistivity of the insulator included in the power receiving / distributing device due to environmental factors shown in FIG. 4 is based on the above-described time dependency formula of the nitrate ion attachment amount and the sulfate ion attachment amount and the color data. , The amount of nitrate ion attached and the amount of sulfate ion attached, and color data are calculated. Then, the Mahalanobis distance is calculated based on the calculated nitrate ion attachment amount, sulfate ion attachment amount, and color data. Further, by calculating the surface resistivity based on a predetermined correlation formula between the surface resistivity and the Mahalanobis distance described in FIG. 2, the time dependency of the surface resistivity of the insulator included in the power receiving and distribution device due to environmental factors is obtained. A curve 201 can be derived.

Next, a method of diagnosing the degree of deterioration of the insulator due to a discharge factor will be described.
FIG. 5 is a diagram illustrating the relationship between the relative humidity (RH%) and the surface resistivity.
As shown in FIG. 5, the surface resistivity changes depending on the relative humidity. A plurality of curves are shown, with the upper curve showing less degradation and the lower curve showing more advanced degradation. From FIG. 5, it can be seen that the surface resistivity decreases as the deterioration progresses even at the same relative humidity.

Here, as the relative humidity increases, the surface resistivity tends to decrease.
For example, in FIG. 5, the surface resistivity at a humidity of 50% RH (P in FIG. 5) is about 1 × 10 ⁺¹¹ Ω, but when the humidity increases to Q% RH in FIG. ⁺⁹ Ω (R _{s in} FIG. 5). Therefore, when the humidity exceeds a certain level, the surface resistivity of the insulator decreases, and when the calculated surface resistivity falls below the surface resistivity at which the discharge occurs, discharge occurs, and when the humidity decreases, the surface resistivity of the insulator increases. , The calculated surface resistivity is higher than the surface resistivity at which the discharge occurs, and no discharge occurs.

In the first embodiment, the amount of nitrate ions deposited due to the discharge is determined by determining the time during which the discharge occurs in the installation environment according to the relative humidity.
Again, in the flow shown in FIG. 1, in the first embodiment, the discharge is generated from the surface resistivity at which the above-described discharge occurs based on a predetermined relational expression between the relative humidity (RH%) and the surface resistivity. The generated relative humidity is calculated (step S11).

Next, the time at which a discharge occurs is calculated from the humidity data (relative humidity) and the partial discharge current data in the environment where the power receiving and distribution device is provided (step S12).
The calculation of the time during which the discharge occurs is performed as follows. The annual discharge generation time is calculated from the annual humidity data of the target electric equipment EM (humidity is 0% to 100% on the horizontal axis, and the vertical axis indicates the accumulated time corresponding to each humidity on the horizontal axis). More specifically, since the threshold value of the surface resistivity at which the discharge occurs has been calculated in step 11, the minimum humidity at which the discharge occurs is determined from FIG. This is the discharge occurrence time.
In addition, as shown in FIGS. 12 and 13, humidity data in the internal environment of the electric equipment panel 11 in which the electric equipment EM as the power receiving and distributing equipment is stored is measured by the humidity detector 14. The partial discharge current data is detected by discharge detection means CD including a power supply voltage phase detector (VT) 12 and a transformer (HFCT) 13.
Here, the partial discharge current is defined as the partial discharge generated on the surface of the insulator provided in the electric device EM as the power receiving and distributing device, and the surface of the insulator is transferred from the power application site of the insulator to the ground wire as the ground site. , And corresponds to the ground line current EC.

When partial discharge occurs in the insulator of the electric device EM, stress is applied to the insulator and the insulator is damaged. The degree of the damage is determined by a ground current area within a predetermined time (= ground current value × time; time integration). The larger and the more frequent the damage, the more severely the insulator will be damaged.
The signal processing unit 15 that processes the detection signal of the discharge detection unit CD detects the waveform of the ground line current EC generated by the electric device (diagnosis target) EM and detected by the transformer (HFCT) due to the partial discharge. The phase is compared with the power supply voltage waveform detected by the detector (VT) 12, and from this comparison result, the identification / evaluation unit 16 identifies and evaluates the occurrence of partial discharge. In other words, attention is paid to the fact that the partial discharge easily occurs at the timing when the amplitude of the power supply voltage waveform of the electric device EM rises (the phase of the power supply voltage waveform is 0 to 90 ° and 180 to 270 °), and the measured electric device EM is used. Is compared with the power supply voltage waveform and the phase, and the ground line current EC within a specific phase range of the power supply voltage waveform is identified and evaluated as being due to partial discharge.

  In comparison with the power supply voltage waveform, the fundamental cycle of the partial discharge waveform is a power supply voltage frequency, for example, a frequency of 100 Hz, which is twice the frequency of 50 Hz. Since the magnitude can be evaluated, the accuracy of partial discharge detection can be further increased.

  In the identification / evaluation unit 16 receiving the output of the discharge detection unit CD, the ground current area (= ground line current value × time; time; Integral). Further, the humidity value of the environment around the device is detected by the humidity detector 14 installed near the electrical device EM to be diagnosed. Using these on-line (real-time) data, the presence or absence of partial discharge and information necessary for its identification and evaluation are provided.

Specifically, the data obtained by the above method are classified into the following four patterns, and correlation coefficients (indexes indicating the degree of insulation deterioration) determined in advance according to the patterns are determined as follows. .
(1) “Ground current area: large” & “humidity: low” ⇒ K1
(2) “Ground current area: large” & “humidity: high” ⇒ K2
(3) “Ground current area: small” & “humidity: low” ⇒ K3
(4) "Ground current area: small"&"humidity:high" ⇒ K4
Here, K1 is close to the end of deterioration and K4 is close to the early stage of deterioration. When arranged in descending order of priority from the viewpoint of life diagnosis, the relationship K1>K2>K3> K4 is satisfied.
In addition, each criterion (classification by numerical values) of ground current area: large / small and humidity: high / low is determined from empirical values based on the results of each diagnostic object.

Then, the correlation coefficient K (any one of K1 to K4) determined as described above is input to the diagnostic device 10 every time discharge is detected. If the state of the discharge occurrence and humidity changes within a certain time with the passage of time,
-When no discharge is detected: K4
・ When the pattern is changed: K = Kt-1 (before change) ⇒ K = Kt (after change)
In this way, by using the correlation coefficients K1 to K4 in online (real-time) monitoring, it is possible to identify and monitor the electrical equipment EM that needs attention.
The correlation coefficients K1 to K4 indicate the degree of caution to the monitor, and do not affect the calculation formula for the remaining short-circuit life diagnosis.
However, in the situation of K1 to K4, there is a high possibility that a partial discharge has occurred on the surface of the insulator. Monitoring will be performed with special care. If necessary, when the state of K1 to K4 is reached, it is also effective to issue an alarm including the classification of K1 to K4 to the supervisor.
Here, the ground current area: large / small and the humidity: high / low are evaluated, and the correlation coefficients: K1 to K4 (4 patterns) are applied. However, this is only an example, and is further subdivided ( n patterns: K1 to Kn).

In addition, since the ground line current value that appears when a partial discharge occurs is very small, it may be difficult to distinguish the ground line current detection value from external noise depending on the installation environment. In such a case, the ground current area measured per certain time at the timing when the amplitude of the power supply voltage waveform increases (the phase of the power supply voltage waveform is 0 to 90 ° and 180 to 270 °) as described above. It is identified and evaluated as the one that detected the discharge, depending on the magnitude of the discharge. In addition, the discharge was detected because of the large number of times that the ground current area was generated as a waveform having an area value equal to or greater than a certain level. It may be a form for identifying and evaluating.
As described above, the presence or absence of the occurrence of the discharge is detected, and the discharge occurrence time is obtained.

  In addition, it is preferable that the electric equipment EM to be diagnosed measure the ground line current EC in which the electric equipment EM and the grounding part are connected by a ground line in a state where the electric equipment EM is independently grounded. This is the case when the ground line current EC is measured in a panel housing that accommodates the device in a state where other devices in the panel are grounded or in a state where the panel housing itself is grounded to the ground. This is because the ground line current EC from the electric device EM to be diagnosed is shunted to these, and it is difficult to determine whether the current is a ground current due to partial discharge generated only in the device.

In the flow shown in FIG. 1 again, next, the attached amount of nitrate ions is calculated based on the calculated discharge occurrence time (step S13).
FIG. 6 is a block diagram illustrating a short-circuit acceleration test device according to the first embodiment.
As shown in FIG. 6, the short-circuit acceleration test apparatus according to the first embodiment includes a transformer 4, a digital oscilloscope 5, and a constant temperature / humidity chamber 6. Then, the insulator 1b is disposed in the constant temperature / humidity chamber 6, and the discharge is generated by applying a voltage to the insulator 1b.

FIG. 7 is a cross-sectional view illustrating the insulator 1 b provided in the constant temperature / humidity chamber 6.
As shown in FIG. 7, here, a polyester insulator 1b that has been deteriorated in advance is provided, and a high-voltage electrode 7 to which a voltage transformed by the transformer 4 is applied is attached to the insulator 1b. In addition, the ground electrode 8 is attached to the insulator 1b, and is configured to generate a discharge by applying a high voltage through the transformer 4.

Then, a discharge was generated in the deteriorated insulator 1b under the conditions of a rated voltage, a humidity of 60 to 90%, and a temperature of 60 ° C., and a change in the amount of attached nitrate ions until a short circuit was measured.
The measurement of the nitrate ion adhesion amount was performed by collecting ions by pressing a filter paper impregnated with pure water against the insulator 1b, and measuring the collected ions by an ion chromatograph.

FIG. 8 is a diagram illustrating a change over time in the amount of nitrate ions attached to the insulator due to discharge.
As shown in FIG. 8, in the first embodiment, the time change of the nitrate ion adhesion amount in the case where the experiment is performed at three kinds of humidity of 90%, 80%, and 60% is shown.
Here, the test time increased and the amount of adhered ions increased at any humidity. The ion adhesion amount was affected by the humidity at the time of the test, and increased as the humidity increased.

  The nitrate ion adhesion amount P (t) adhering to the insulator due to the discharge is expressed as the following equation (2) as a function of time and humidity.

Here, a is a constant and takes the following values. t represents a discharge occurrence time, and h represents humidity. A ≦ 5, 60 <h ≦ 70; a = 10, 70 ≦ h; a = 15.
The nitrate ion adhesion amount represented by the above equation (2) is an amount that adheres when a discharge is constantly generated. However, as described above, in an actual installation environment of equipment, the humidity constantly changes. Discharge occurs when the humidity is equal to or higher than that, and no discharge occurs when the humidity decreases.
Therefore, according to the above equation (2), the attached amount of nitrate ions due to the discharge at the installation site of the power receiving and distribution device can be obtained.

  In the flow shown in FIG. 1 again, next, the surface resistivity after the occurrence of the discharge is calculated (step S14). Specifically, the surface resistivity of the insulator after the occurrence of discharge is calculated based on the amount of nitrate ion attached, the amount of attached sulfate ion and color data due to environmental factors, and the amount of nitrate ion attached due to the discharge factor.

Then, a time-dependent curve of the surface resistivity after the occurrence of the discharge is derived (step S15).
FIG. 9 is a diagram illustrating a time-dependent curve of the surface resistivity of an insulator included in a power receiving and distribution device due to environmental factors and discharge factors.
In FIG. 9, a time-dependent curve 201 of the surface resistivity of the insulator due to environmental factors is indicated by a dotted line, and a time-dependent curve 202 of the surface resistivity of the insulator after the occurrence of discharge is indicated by a solid line.
Specifically, the distance of the Mahalanobis is calculated from the nitrate ion attachment amount and the sulfate ion attachment amount and the color data every year based on the above formula. Then, by calculating the surface resistivity based on a predetermined correlation equation between the surface resistivity and the Mahalanobis distance described in FIG. It is possible to derive a time dependency curve (second time dependency curve) 202 relating to the surface resistivity.

Then, in the flow shown in FIG. 1 again, the remaining short-circuit life is diagnosed in accordance with the derived time-dependent curve relating to the surface resistivity of the insulator (step S16).
Specifically, in FIG. 9, the remaining short-circuit life is determined from a time-dependent curve (second time-dependent curve) 202 of the surface resistivity of the insulator after the occurrence of discharge and a predetermined short-circuit threshold.
As the short-circuit threshold, a value obtained by actually measuring the surface resistivity at the time of short-circuit by a short-circuit acceleration test was used. As an example, in a short-circuit acceleration test at a humidity of 90%, the amount of attached nitrate ions at the time of short-circuit was 1.5 mg / cm ² .

As described above, the distance of Mahalanobis is calculated based on the nitrate ion attachment amount and the sulfate ion attachment amount due to environmental factors and the color data, and the nitrate ion attachment amount due to the discharge. As a result of calculating the surface resistivity of the insulator based on the results, the surface resistivity at a humidity of 90% was 2.5 × 10 ⁴ Ω, and the surface resistivity at a humidity of 50% was 2.5 × 10 ⁶ Ω. Therefore, the surface resistivity serving as the short-circuit threshold was set to 2.5 × 10 ⁶ Ω. The above is merely an example, and the threshold is actually determined according to the shape of the insulator and the result of the local environmental survey.

  Referring to FIG. 9 again, power receiving and distribution equipment is calculated by calculating a short-circuit life from a time-dependent curve (second time-dependent curve) 202 of the surface resistivity of the insulator after the occurrence of discharge in accordance with the short-circuit threshold. It is possible to accurately diagnose the remaining short-circuit life of the insulator included in the above.

If it is determined in step S5 that the calculated surface resistivity is smaller than the surface resistivity at which discharge occurs, the process proceeds to step S6. In the same manner as described in steps S12 and S13 , the humidity data of the environment where the insulator is installed and the partial discharge current are calculated, and the nitrate ion adhesion amount due to the discharge factor is calculated (step S6).
The nitrate ion adhesion amount due to environmental factors is determined by subtracting the nitrate ion adhesion amount due to the discharge factor calculated in step S6 from the nitrate ion adhesion amount attached to the insulator obtained in step S3 (step S7).
The reason for performing the above-described operation in step S7 is to grasp the "discharge occurrence" point in FIG. That is, if it is determined in step S5 that the surface resistivity is smaller than the surface resistivity at which the discharge occurs, the discharge has already occurred several times in the past at that time, and the remaining short-circuit life At the time of execution of the diagnosis, it is located somewhere on the time dependency curve (second time dependency curve) 202 of the surface resistivity due to the discharge factor extending to the lower right from the position of “discharge occurrence” in FIG. Will be. Therefore, in step S6, the amount of attached nitrate ions due to the discharge factor is obtained, and in step S7, the amount of attached nitrate ions due to the discharge factor is subtracted from the amount of attached nitrate ions attached to the insulator to obtain the amount of attached nitrate ions due to environmental factors. First, a time-dependent curve (first time-dependent curve) 201 of the surface resistivity of the insulator due to environmental factors is obtained. Next, using the time-dependent curve (second time-dependent curve) 202 of the nitrate ion adhesion amount due to the discharge factor and the surface resistivity due to the discharge factor calculated in step S6, from the “discharge occurrence” point in FIG. The elapsed time up to the current position is calculated backward to identify the “discharge occurrence” point in FIG. In this way, the time dependency curve (first time dependency curve) 201 of the surface resistivity of the insulator due to environmental factors and the time dependency curve (second time dependency curve) of the surface resistivity due to discharge factors as shown in FIG. (Time dependency curve) 202 is determined.
Hereinafter, similarly to the steps S8 to S16, the first time dependency curve 201 and the second time dependency curve 202 are derived to calculate the remaining short-circuit life.
If the process does not go through steps S6 and S7, that is, if it is determined in step S5 that "the surface resistivity at which discharge occurs is greater than the surface resistivity", only environmental factors are used during the period from when the diagnosis is performed to when discharge occurs. After the occurrence of discharge, the remaining short-circuit life is calculated using only the time-dependent curve (second time-dependent curve) 202 of the surface resistivity due to environmental factors and discharge factors.

In the description of FIG. 9, at the time of the diagnosis (A), the measurement data of the contamination status of the surface of the insulator to be diagnosed and the measurement data of the humidity environment (seasonal season) Time-dependent curve (first time-dependent curve) 201 of the surface resistivity due to environmental factors and the time-dependent curve of the surface resistivity of the insulator after the occurrence of electric discharge, based on the humidity measurement data at different times. (Second time dependency curve) 202 is calculated, and the remaining time until the short circuit threshold (short circuit remaining life) is calculated using the first time dependency curve 201 and the second time dependency curve 202. I was
In this case, the discharge occurrence timing in FIG. 9 is a predicted value calculated from the surface resistivity (Rs) at which the discharge is calculated in advance and the first time dependency curve 201, and further the second time dependency. The curve 202 shows the surface resistivity (predicted value) at the start of discharge predicted in advance at the time of diagnosis (A) and the measured data of the humidity environment measured at the time of diagnosis (A). This is also a predicted value. As described above, the discharge occurrence time and the time to reach the short-circuit threshold in FIG. 9 are all prediction values based on the measurement at the time of diagnosis (A), and the pollution environment and humidity at the installation location of the power receiving and distribution equipment to be diagnosed are Due to changes in the environment, there is a possibility of an error in the short-circuit remaining life diagnosis.

Since power receiving and distribution equipment directly affects the continuity of operation of important production equipment such as factories, improving the accuracy of remaining life diagnosis is an important issue. From this point of view, by actually measuring the occurrence point of the partial discharge, which is the intermediate stage of the remaining short-circuit life, it is necessary to determine the two surface resistivity values (the partial discharge occurrence stage, the short-circuit threshold value), which are all predicted values, as shown in FIG. Compared to those that use short-circuit remaining life diagnosis,
By correcting the partial discharge occurrence time with the actually measured value, the accuracy of the remaining short-circuit life diagnosis can be improved as compared with that of FIG.
FIGS. 10 and 11 show a time dependency curve (first time dependency curve) of the surface resistivity due to environmental factors by accurately measuring the start time of the partial discharge by actually measuring the partial discharge. ) 201 and the time dependency curve (second time dependency curve) 202 of the surface resistivity of the insulator after the occurrence of discharge is corrected to improve the accuracy of diagnosis of remaining short-circuit life.

  FIG. 10 shows a case where the start time “x” of the partial discharge is later than the discharge start time predicted in FIG. The time dependency curve (first time dependency curve) 201 of the surface resistivity due to environmental factors from the time lapse between the initial diagnosis execution time (A) and the actual partial discharge occurrence time “x” is shown in FIG. Is corrected in the form of the first time-dependent curve 201a having a longer life than the initial prediction (the slope of the broken line 201 is smaller), and further along the above-described steps in FIG. The time dependency curve (second time dependency curve) 202a of the surface resistivity of the insulator after the occurrence of a new discharge is also corrected using the data of the surface resistivity at the actual partial discharge occurrence time "x". . Using the corrected second time dependency curve 202a, the time from the actually measured discharge occurrence (actually measured) time "x" to the new short circuit threshold reaching time (C) is calculated as the remaining short circuit life. In this way, the first time dependency curve 201a and the second time dependency curve 202a are newly obtained by actually measuring the partial discharge start time, which is an intermediate time until the short circuit threshold is reached, to obtain the one shown in FIG. In comparison, it is possible to improve the accuracy of the remaining short-circuit life diagnosis until the short-circuit threshold is reached.

  FIG. 11 shows a case where the start point “x” of the partial discharge is earlier than the discharge start point predicted in FIG. 9. The time dependence curve (first time dependence curve) 201 of the surface resistivity due to environmental factors from the time lapse between the initial diagnosis execution time (A) and the actual partial discharge occurrence time “x” is shown in FIG. Is corrected to a first time-dependent curve 201a having a shorter life than the initial prediction (the slope of the broken line 201 is larger) than the initial prediction, and further along the above-described steps in FIG. The time dependency curve (second time dependency curve) 202a of the surface resistivity of the insulator after the occurrence of the new discharge is also corrected using the data of the surface resistivity at the actual partial discharge occurrence time “x”. Using the corrected second time dependency curve 202a, the time from the actually measured discharge occurrence (actually measured) time "x" to the new short circuit threshold reaching time (C) is calculated as the remaining short circuit life. In this way, the first time dependency curve 201a and the second time dependency curve 202a are newly obtained by actually measuring the partial discharge start time, which is an intermediate time until the short circuit threshold is reached, to obtain the one shown in FIG. In comparison, it is possible to improve the accuracy of the remaining short-circuit life diagnosis until the short-circuit threshold is reached. As a result, it is possible to avoid accidents due to insulation deterioration by ensuring maintenance and updating of power distribution equipment, and to improve the reliability of continuation of operation of important production equipment such as factories. It becomes.

  According to the method of diagnosing remaining short-circuit life in the first embodiment, since deterioration due to both environmental factors and discharge factors is taken into consideration, diagnosis can be performed regardless of the occurrence of discharge and the degree of deterioration of the insulator. Yes, chemical evaluation of ion amount and color data that is not affected by humidity enables high-precision diagnosis, and enables accurate diagnosis of remaining short-circuit life of insulators included in power receiving and distribution equipment. Thus, electrical trouble due to the deterioration of the insulator can be prevented.

  In the above, the method using nitrate ion attachment amount and sulfate ion attachment amount and color data as chemical evaluation items for obtaining the surface resistivity of the insulator has been described, but depending on the type of the insulator and the installation environment, The method shall use ion adhesion amount and color data such as chloride ion, sodium ion, calcium ion and ammonium ion, gloss and insulation components such as ester, phenol, epoxy, hydrocarbon and silicate. Is also possible. In the above step S9, the time dependency equation of the nitrate ion adhesion amount was obtained. However, an appropriate acceleration test is performed according to the evaluation item used, and the change of the evaluation item is analyzed to measure the evaluation item. It is also possible to determine the time dependence of the quantity.

As shown in FIGS. 1 to 13, the following method is disclosed as a method of diagnosing remaining short-circuit life of a power receiving and distribution device in the first embodiment.
A method for diagnosing a remaining short-circuit life of a power receiving and distribution device having an insulator, the method comprising: calculating a surface resistivity of the insulator, wherein the surface resistivity is smaller than a discharge occurrence value. If the value is larger, a step S10 of deriving a first time-dependent curve due to environmental factors relating to the surface resistivity of the insulator based on environmental factor data including the nitrate ion adhesion amount of the insulator; Humidity data as a result of measurement by the hygrometer 14 of the environment in which the current is flowing, and a partial discharge current measurement result by the discharge detection means CD including a transformer (HFCT) for measuring the ground line current EC and a power supply voltage phase detector (VT). Calculating a discharge occurrence time; calculating a nitrate ion attachment amount due to a discharge factor based on the discharge occurrence time; Steps S13 to S15 for deriving a second time-dependent curve relating to the surface resistivity of the insulator based on the data and the surface resistance of the insulator calculated based on the second time-dependent curve. Calculating a remaining short-circuit life from the ratio and a predetermined short-circuit threshold.

  According to this method, the discharge current measurement result obtained by measuring the ground line current EC due to the partial discharge and the humidity data of the environment in which the insulator is installed detected by the humidity detector 14 are used to remove the insulator caused by the discharge factor. Calculates the amount of nitrate ion deposition and considers insulation deterioration due to both environmental and discharge factors to calculate the remaining short-circuit life based on environmental factor data including nitrate ion deposition and nitrate ion deposition due to discharge factors. Therefore, it is possible to accurately diagnose the remaining short-circuit life.

Further, as a method of diagnosing the remaining short-circuit life of the power receiving and distribution device in the first embodiment, the following method is disclosed as shown in FIGS.
Inputting a use condition of a power receiving / distributing device to be diagnosed and a parameter condition of an insulator of the power receiving / distributing device; and a surface resistance at which discharge of the insulator occurs based on the input use condition and the input parameter condition. A step S1 of calculating a rate, a step S2 of measuring a nitrate ion attachment amount and a sulfate ion attachment amount of the insulator, and a color parameter of the insulator, and the insulation according to a result of the measurement obtained in the step S3. Step S4 of calculating the surface resistivity of the body, and Step S5 of determining whether the calculated surface resistivity of the insulator is greater than the surface resistivity at which the discharge of the insulator occurs. According to step S5, it was determined that the calculated surface resistivity of the insulator was higher than the surface resistivity at which discharge of the insulator occurred. In this case, steps S8 and S9 for deriving the time-dependent expressions for the nitrate ion attachment amount and the sulfate ion attachment amount of the insulator and the color parameter of the insulator, and the time-dependent expression derived in step S9, Step S10 of deriving a first time-dependent curve of the surface resistivity of the insulator due to environmental factors, and measuring the humidity data and the partial discharge current of the environment in which the insulator is installed to determine the discharge occurrence time. Calculating step S12, calculating the nitrate ion adhesion amount due to the discharge factor from the calculated discharge occurrence time, and calculating the nitrate ion adhesion amount by the discharge and the nitrate ion adhesion amount and the sulfate ion adhesion amount by the environment. And deriving a second time-dependent curve of the surface resistivity of the insulator based on the color parameter of the insulator 15 and a step S16 of calculating a remaining short-circuit life from the surface resistivity of the insulator calculated in the step S14 and a predetermined short-circuit threshold based on the second time dependency curve. Features.
When it is determined that the surface resistivity of the insulator calculated in step S5 is smaller than the surface resistivity at which the discharge of the insulator occurs, the amount of ion deposition and the discharge factor due to environmental factors are determined as follows. To distinguish the amount of attached ions. In other words, means for measuring the humidity data of the environment where the insulator is installed and the partial discharge current to calculate the amount of nitrate ion attached due to the discharge factor, and the amount of ion attachment due to the discharge factor based on the amount of nitrate ion attached to the insulator Is subtracted to obtain the amount of nitrate ions deposited due to environmental factors. Hereinafter, similarly to the above step, the first time dependency curve and the second time dependency curve are derived to calculate the remaining short-circuit life.
Specifically, the calculation of the remaining short-circuit life is shown in FIG. 9 at the time of diagnosis (A), the time dependency curve (second time dependency curve) 202 of the surface resistivity of the insulator after the occurrence of discharge, and The remaining short circuit life is determined from the horizontal distance (time) from the intersection (B) with a predetermined short circuit threshold.
In FIG. 10 and FIG. 11, a time dependency curve (second time dependency curve) 202a of the surface resistivity of the insulator after the occurrence of the discharge “×” and the discharge after the occurrence of the discharge (the second time dependency curve) 202a is predetermined. The remaining short circuit life is determined from the horizontal distance (time) from the intersection (C) with the short circuit threshold value.

By using the discharge current and the humidity data according to this method, a first time dependency curve of the surface resistivity of the insulator due to environmental factors and a second time dependency curve of the surface resistivity of the insulator due to the discharge factors Is accurately derived and the remaining short-circuit life is calculated based on the first and second time-dependency curves, and the deterioration due to both environmental factors and discharge factors is taken into account. This makes it possible to make a good diagnosis. Then, the measurement of the surface resistance value and the like required for the estimation can be performed online (real time) without restrictions such as a power failure operation, and the life of the electric device can be easily and accurately determined.・ Economical renewal can be performed.
If it is determined that the surface resistivity of the insulator calculated in step S5 is smaller than the surface resistivity at which the insulator is discharged, the humidity data of the environment where the insulator is installed and the partial discharge By using the current measurement result, the amount of nitrate ions deposited due to environmental factors can be accurately obtained.

Embodiment 2 FIG.
Next, a description will be given of a system for realizing the remaining short-circuit life diagnosis of the power receiving and distribution device using the above-described remaining short-circuit life diagnosis method.
FIG. 14 is a schematic configuration diagram of a system for diagnosing remaining short-life of a power receiving and distribution device according to the second embodiment.
The remaining short-circuit life diagnosis system according to the second embodiment diagnoses the remaining short-circuit life of an insulator included in a power receiving and distribution device, and its operation is controlled by a program recorded on a recording medium such as a magnetic disk. Computer.
The remaining short-circuit life diagnosis system according to the second embodiment relates to an execution device having means for realizing the operation of the above-described remaining short-life diagnosis method according to the first embodiment. 1 corresponds to each step of the remaining short-circuit life diagnosis method.

As shown in FIG. 14, the system 100 for diagnosing remaining short-life of a power receiving and distribution device according to the first embodiment includes an input unit 111, a storage unit 112, a control unit 113, a detection unit 114, and an output unit 115.
The input unit 111 includes an input device including, for example, a keyboard, a mouse, and a tablet, and inputs various data necessary for diagnosing the remaining short-circuit life of the insulator.

The storage unit 112 is composed of a memory device including, for example, a ROM and a RAM, and stores a program for realizing the configuration according to the second embodiment and various data necessary for diagnosing the remaining short-circuit life.
The control unit 113 includes a microprocessor (CPU), and reads a program stored in the storage unit 112 to execute a process related to diagnosis of remaining short-circuit life according to a procedure described in the program.
The detection unit 114 detects the relative humidity and the partial discharge current, and performs data processing on the partial discharge current.
The output unit 115 includes, for example, a display device and outputs a diagnosis result of the remaining short-circuit life.

In such a configuration, it is assumed that the storage unit 112 stores a predetermined correlation equation between the surface resistivity and the Mahalanobis distance described with reference to FIG.
It is assumed that the storage unit 112 also stores an expression for calculating and calculating the Mahalanobis distance.
Also, the storage unit 112 stores the equation (1), which is the time-dependent equation of the amount of nitrate ions deposited due to environmental factors, described in the description of the experimental apparatus in FIG. 3, and the predetermined values of the relative humidity and the surface resistivity in FIG. , And data that can be subjected to arithmetic processing in equation (2) for calculating the amount of attached nitrate ions due to discharge based on the measurement data in FIG. 8 obtained by the test using the short-circuit acceleration test apparatus described in FIG. It is assumed that

First, the input unit 111 inputs the rated voltage and operating frequency of the power receiving and distribution device to be diagnosed, and the setting conditions of the thickness, creepage distance, and dielectric constant of the insulator included in the power receiving and distribution device.
The input unit 111 also inputs the measured amounts of nitrate ion attachment amount, sulfate ion attachment amount, and color data of the insulator of the power receiving / distributing device to be diagnosed as parameters regarding the insulator of the power receiving / distributing device. Then, the number of years of use of the power receiving / distributing device is input through the input unit 111. Further, a predetermined short-circuit threshold value of the insulator used in the power receiving and distribution device is input through the input unit 111.

After these data are stored in the storage unit 112, the processing of steps S1 to S16 in the above-described first embodiment is performed. Is done.
(1) First, based on the rated voltage and operating frequency of the power receiving and distribution device to be diagnosed and the thickness, creepage distance, and dielectric constant of the insulator included in the power receiving and distribution device, which are input by the input unit 111. Then, the surface resistivity at which discharge and short circuit occur is calculated (corresponding to step S1).
(2) Next, the Mahalanobis distance is calculated based on the nitrate ion sulfate amount and the sulfate ion deposit amount and the color data of the insulator of the power receiving and distribution device to be diagnosed, which are input as parameters by the input unit 111, The surface resistivity is calculated based on a predetermined correlation formula between the surface resistivity and the Mahalanobis distance described in FIG. 2 (corresponding to steps S2 to S4).

(3) Then, the surface resistivity at which discharge occurs, the surface resistivity calculated based on the nitrate ion attachment amount and the sulfate ion attachment amount of the insulator of the power receiving and distribution device to be diagnosed, and the color data are calculated. The surface resistivity calculated based on the nitrate ion attachment amount and the sulfate ion attachment amount and the color data of the insulator of the power receiving and distribution device to be diagnosed is greater than the surface resistivity at which discharge occurs. Is determined to be larger (corresponding to step S5).
(4) According to the result of the comparison operation, the surface resistivity calculated based on the nitrate ion attachment amount and the sulfate ion attachment amount of the insulator of the power receiving and distribution device to be diagnosed and the color data is the surface resistance at which discharge occurs. If the ratio is larger than the ratio, the ratio of the sulfate ion adhesion amount and the color data to the nitrate ion adhesion amount is calculated (corresponding to step S8).

(5) Then, based on the number of years of use of the power receiving / distributing device to be diagnosed, which is input as a parameter by the input unit 111, and the actually measured data of the amount of attached nitrate ions, a time-dependent expression of the amount of attached nitrate ions is used. The apparent NOx concentration A in the atmosphere of the environment in which the power receiving and distribution device to be diagnosed is installed is calculated using a certain equation (1).
(6) Then, a time-dependent expression of the nitrate ion adhesion amount due to environmental factors of the insulator of the power receiving / distributing device, in which the calculated apparent NOx concentration in the atmosphere A of the environment is substituted into Expression (1), is derived (Step S9). Equivalent).

(7) Based on the time dependency of nitrate ion deposition due to environmental factors, the time dependence of sulfate ion deposition due to environmental factors is determined using the ratio of sulfate ion deposition and color data to nitrate ion deposition calculated above. A time dependency formula of color data based on the sex formula and environmental factors is derived (corresponding to step S9).
(8) Then, based on the above-described time dependency formulas of the nitrate ion attachment amount and the sulfate ion attachment amount and the color data, as described with reference to FIG. A time dependency curve of the surface resistivity is derived (corresponding to step S10).

(9) Then, based on the predetermined correlation equation between the relative humidity and the surface resistivity described with reference to FIG. 5, the relative humidity at which the discharge occurs is calculated from the calculated surface resistivity at which the discharge occurs (step). S11).
(10) Then, a discharge occurrence time is calculated based on the result of monitoring the humidity of the electric room and the result of monitoring the discharge current (corresponding to step S12).

(11) Then, in accordance with the equation (2) based on the measurement data in FIG. 8 obtained by the test using the short-circuit acceleration test apparatus described in FIG. The amount of nitrate ions attached due to the discharge of the battery is calculated (corresponding to step S13).
(12) Then, in accordance with the above-described procedure, the surface resistivity after the occurrence of the discharge is calculated based on the nitrate ion attachment amount and the sulfate ion attachment amount due to environmental factors, the color data, and the nitrate ion attachment amount due to the discharge. (Corresponding to step S14).

(13) Then, a time-dependent curve of the surface resistivity of the insulator included in the power receiving and distribution device due to environmental factors and discharge factors is derived according to the above-described procedure (corresponding to step S15).
(14) Then, a remaining short-circuit life is calculated from the derived time-dependent curve of the surface resistivity of the insulator and a predetermined short-circuit threshold value input as input data by the input unit 111 (corresponding to step S16).
(15) Then, the calculation result is output to the output unit 114 which is a display device, for example.

  Determines whether the calculated surface resistivity based on the nitrate and sulfate ion adhesion amounts and the color data of the insulator of the power receiving and distribution equipment to be diagnosed is greater than the surface resistivity at which discharge occurs If it is determined that the surface resistivity calculated by the means for performing the discharge is smaller than the surface resistivity at which the discharge occurs, the humidity data of the environment where the insulator is installed and the partial discharge current are measured, and the nitrate ion adhesion due to the discharge factor is measured. Calculate the amount.

  The nitrate ion attachment amount due to environmental factors is determined by subtracting the nitrate ion attachment amount due to discharge factors from the nitrate ion attachment amount attached to the insulator. Hereinafter, similarly to the above step, the first time dependency curve and the second time dependency curve are derived to calculate the remaining short-circuit life.

  That is, in the short-circuit remaining life diagnosis system for diagnosing the remaining short-circuit life of the power receiving / distributing device according to the second embodiment, the use condition of the power receiving / distributing device to be diagnosed, the parameter condition of the insulator of the power receiving / distributing device, and the measurement Means for inputting the amount of nitrate and sulfate ions attached to the insulator and the color parameter of the insulator, and control means for diagnosing the remaining short-circuit life, wherein the control means includes the input use conditions and parameters. Means for calculating the surface resistivity at which the discharge of the insulator occurs based on the conditions; and performing insulation according to the measured amount of nitrate and sulfate ions attached to the insulator and the color parameter of the insulator. Means for calculating the surface resistivity of the body, and the surface resistivity of the insulator calculated by the means for executing steps S2 to S4 The execution means of step S5 for determining whether or not the surface resistivity at which the discharge occurs is determined by the execution means of step S5, and the calculated surface resistivity of the insulator is determined by the surface resistance at which the discharge of the insulator occurs. If it is determined that the ratio is greater than the rate, the execution means of steps S8 and S9 for deriving a time-dependent equation for the nitrate ion attachment amount and the sulfate ion attachment amount of the insulator and the color parameter of the insulator; Executing means for deriving a first time-dependent curve of the surface resistivity of the insulator due to environmental factors based on the time-dependent equation derived by the executing means; and generating a discharge from the humidity data and the discharge current data. The amount of nitrate ion adhered by the discharge is calculated from the execution means of step S12 for calculating the time and the discharge occurrence time calculated by the execution means of step S12. The surface resistivity of the insulator based on the execution means of step S13 and the nitrate ion adhesion amount due to the discharge, the nitrate ion adhesion amount and the sulfate ion adhesion amount due to the environment, and the color parameter of the insulator calculated by the execution means of step S13. Means for executing steps S14 and S15 for deriving a second time-dependent curve, and a short-circuit based on the calculated surface resistivity of the insulator and a predetermined short-circuit threshold based on the second time-dependent curve. Means for calculating the remaining life.

  Further, the surface resistivity of the insulator calculated by the execution means of step S5 for determining whether the surface resistivity of the insulator is greater than the surface resistivity at which the discharge of the insulator occurs is determined by the fact that the discharge of the insulator is not generated. If it is determined that the surface resistivity is smaller than the surface resistivity, the method includes a means for distinguishing the ion adhesion amount due to environmental factors and the ion adhesion amount due to discharge factors as described below. That is, the means for executing the step S6 of measuring the humidity data and the partial discharge current of the environment in which the insulator is installed and calculating the amount of nitrate ion attached due to the discharge factor, and the discharge factor based on the amount of nitrate ion attached to the insulator. And means for executing step S7 for obtaining the nitrate ion adhesion amount due to environmental factors by subtracting the nitrate ion adhesion amount due to environmental factors.

  According to the system for diagnosing remaining short-life of power receiving and distribution equipment described in the second embodiment, a diagnosis result can be obtained quickly at the installation site of the equipment without bringing back data, so that maintenance and renewal planning of the insulator can be made easier. Can be implemented quickly. In addition, since highly accurate diagnosis is possible, it is possible to use the power receiving and distributing device for a long period of time while ensuring reliability and stability.

  The embodiment disclosed this time is an example in all respects and should be considered as not being restrictive. The disclosed items as the technical concept in this application can be freely combined with each other or can be appropriately modified or omitted within the technical scope thereof. The technical scope in this application 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.

1a, 1b insulator, 2 nitric acid, 3 desiccator, 4 transformer, 5 digital oscilloscope, 6 constant temperature / humidity chamber, 7 high voltage electrode, 8 ground electrode, 10 diagnostic device, 11 electric equipment panel, 12 power supply voltage phase detector (VT), 13 transformer (HFCT), 14 humidity detector, 15 signal processing unit, 16 identification / evaluation unit, 100 short-circuit remaining life diagnosis system, 111 input unit, 112 storage unit, 113 control unit, 114 detection unit, 115 output unit, 201, 201a first time dependency curve, 202, 202a second time dependency curve, CD discharge detection means, EC ground line current, EM electrical equipment.

Claims (6)

A method for diagnosing remaining short-circuit life of a power receiving and distribution device having an insulator, the method further comprising:
Calculating the surface resistivity of the insulator;
When the surface resistivity is larger than a discharge occurrence value, a first time dependency of environmental factors relating to the surface resistivity of the insulator is derived based on environmental factor data including nitrate ion adhesion amount of the insulator. Steps and
Calculating the discharge occurrence time based on the humidity data and the partial discharge current measurement result of the environment where the insulator is installed,
The amount of nitrate ions attached due to the discharge factor is calculated based on the discharge occurrence time, and the second time dependency of the surface resistivity of the insulator is derived based on the amount of nitrate ions attached to the discharge factor and the environmental factor data. And calculating a remaining short-circuit life by performing the method. A method for diagnosing remaining short-circuit life of a power receiving and distribution device having an insulator, the method further comprising:
Inputting the use condition of the power receiving and distribution device to be diagnosed and the parameter condition of the insulator of the power receiving and distribution device,
Calculating a surface resistivity at which discharge of the insulator occurs based on the input use condition and the parameter condition,
Measuring the nitrate ion deposition amount and the sulfate ion deposition amount of the insulator and the color parameter of the insulator;
Calculating a surface resistivity of the insulator according to the result of the measurement;
Determining whether the calculated surface resistivity of the insulator is greater than the surface resistivity at which discharge of the insulator occurs,
When it is determined that the surface resistivity of the insulator calculated by the determining step is higher than the surface resistivity at which the discharge of the insulator occurs, the nitrate ion attachment amount and the sulfate ion attachment of the insulator are determined. Deriving the time dependence of the quantity as well as the color parameter of the insulator;
Deriving a first time dependency of a surface resistivity of the insulator due to environmental factors based on the derived time dependency;
Calculating the discharge occurrence time based on the measurement result of the humidity data and the partial discharge current of the environment where the insulator is installed,
Calculating a nitrate ion adhesion amount due to a discharge factor from the calculated discharge occurrence time;
Second time dependency of the surface resistivity of the insulator based on the calculated amount of nitrate ion attached due to discharge factors and the amount of nitrate ion attached and sulfate ion attached due to environmental factors and the color parameter of the insulator. Deriving; and
A step of calculating a remaining short-circuit life from the calculated surface resistivity of the insulator and a predetermined short-circuit threshold based on the second time dependency. Short-circuit remaining life diagnosis method.   If the calculated surface resistivity of the insulator is equal to or less than the surface resistivity at which the discharge of the insulator occurs, the discharge factor is determined by the humidity data of the environment where the insulator is installed and the partial discharge current measurement result. Calculating a nitrate ion adhesion amount and subtracting a nitrate ion adhesion amount due to a discharge factor from the nitrate ion adhesion amount adhering to the insulator to obtain a nitrate ion adhesion amount due to environmental factors. 3. The method for diagnosing remaining short-circuit life of a power receiving and distribution device according to claim 1 or 2. Calculating the discharge occurrence time from the humidity data of the environment in which the insulator is installed and the partial discharge current measurement result,
Measuring the ground line current as a means for detecting partial discharge;
Extracting the ground line current occurring within a specific phase range of the power supply voltage waveform by comparing the ground line current with the power supply voltage waveform and phase, as a result of partial discharge;
The method according to any one of claims 1 to 3, further comprising a step of measuring the humidity of the installation environment and detecting the occurrence of discharge by comparing the measured humidity with the magnitude of the extracted ground line current. The method for diagnosing the remaining short-circuit life of the power receiving and distribution equipment described in the above. A short-circuit remaining life diagnosis system for diagnosing a remaining short-circuit life of a power receiving and distribution device having an insulator,
Means for inputting the use conditions of the power receiving / distributing device to be diagnosed and the parameter conditions of the insulator of the power receiving / distributing device, and the measured nitrate ion attachment amount and sulfate ion attachment amount of the insulator and the color parameter of the insulator; Equipped with control means for diagnosing the remaining short-circuit life,
The control means includes:
Means for calculating a surface resistivity at which discharge of the insulator occurs based on the input use conditions and parameter conditions,
Means for calculating the surface resistivity of the insulator, according to the measured nitrate ion attachment amount and sulfate ion attachment amount of the insulator and the color parameter of the insulator,
Means for determining whether the calculated surface resistivity of the insulator is greater than the surface resistivity at which discharge of the insulator occurs,
When the determining means determines that the calculated surface resistivity of the insulator is larger than the surface resistivity at which the discharge of the insulator occurs, the nitrate ion adhesion amount and the sulfate ion of the insulator are determined. Means for deriving the amount of deposition and the time dependence on the color parameter of the insulator;
Means for deriving a first time dependency of the surface resistivity of the insulator due to environmental factors based on the derived time dependency;
Means for calculating the discharge occurrence time based on the humidity data of the environment where the insulator is installed and the partial discharge current measurement result,
Means for calculating a nitrate ion adhesion amount due to discharge from the calculated discharge occurrence time,
Second time dependency of the surface resistivity of the insulator based on the calculated amount of nitrate ion attached due to discharge factors and the amount of nitrate ion attached and sulfate ion attached due to environmental factors and the color parameter of the insulator. Means for deriving
A means for calculating a remaining short-circuit life from the calculated surface resistivity of the insulator and a predetermined short-circuit threshold based on the second time dependency. Life diagnosis system. Means for determining whether or not the calculated surface resistivity of the insulator is greater than the surface resistivity at which the discharge of the insulator occurs, wherein the calculated surface resistivity of the insulator is the discharge of the insulator; If it is determined that the surface resistivity is less than or equal to, the means for measuring the humidity data and the partial discharge current of the environment where the insulator is installed and calculating the nitrate ion adhesion amount due to the discharge factor, 6. The remaining short-circuit life of the power receiving / distributing device according to claim 5, further comprising means for subtracting the amount of nitrate ion attached due to discharge from the amount of attached nitrate ion to obtain the amount of attached nitrate ion due to environmental factors. Diagnostic system.

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