JP6941994B2 - Methods and equipment for evaluating the decrease or recovery from the decrease in the insulation resistance value of an insulator - Google Patents

Description

The present invention relates to a method and an apparatus for estimating the insulation resistance value of an insulator and evaluating the decrease in the insulation resistance value or the recovery from the reduced state based on the estimated insulation resistance value.

Factors that reduce the insulation resistance value of insulation in equipment such as electrical equipment include thermal deterioration factors, mechanical deterioration factors, aging deterioration factors for insulation performance of insulation such as electrical deterioration factors, and environmental factors. There is a temporary decrease in insulation resistance. These differ depending on the installation environment, usage conditions, inspection implementation status, etc. Recently, there are increasing expectations for deterioration diagnosis technology that aims to systematically maintain equipment and prevent serious accidents by grasping the deterioration state in a broad sense, including the decrease in the insulation resistance value of equipment. For example, Patent Document 1).

For example, in order to estimate the decrease in insulation resistance value due to environmental factors, the insulation resistance value of the insulator is based on the measurement of the insulation resistance value, temperature and humidity, fouling degree, ion content, etc. of the insulating material and the characteristic evaluation factors. (For example, Patent Document 2 and Non-Patent Document 1-3).

Another method of diagnosing a decrease in the insulation resistance value of an insulator due to environmental factors is to simply monitor the humidity rise and dew point temperature of the equipment, predict the dew condensation on the surface of the insulator, and insulate the insulation resistance of the insulator. Many have been devised to estimate the decrease in value.

As shown in FIG. 14, the relationship between the relative humidity and the partial discharge extinction voltage (100 pC) changes according to the equivalent salt adhesion density (fouling degree). From this, it can be seen that there is a relationship between the discharge start voltage, the relative humidity, and the equivalent salt adhesion density (fouling degree) (for example, Non-Patent Document 4). Further, as shown in FIG. 15, the leakage current is caused by the change in humidity and the degree of contamination due to the change in the leakage current value between the state without contamination and the contamination state with the equivalent salt adhesion density of 0.01 mg / cm ^2. It is clear that it will increase.

Thus, surface fouling of the insulator is an important characterization factor. For example, in electrical equipment, if the equivalent salt adhesion density, which is an index of surface contamination of insulation, is 0.03 mg / cm ² or less, even if the surface of the insulator is dewed, there is almost no direct accident. .. However, it is clear from many experimental results that when the equivalent salt adhesion density is 0.06 mg / cm ² or more, the insulation resistance value decreases significantly as the humidity inside the device rises (for example, relative humidity is 75% or more). (For example, Non-Patent Documents 3 and 5).

Japanese Unexamined Patent Publication No. 2014-066533 JP-A-2002-333398

Kazushi Kiryu, Kazuhiro Noda, "Comprehensive diagnostic evaluation method for power receiving and transforming equipment and various live-line diagnostic techniques", Meiden Jiho, Vol. 353, 2016 No. 4. Meidensha Co., Ltd., October 25, 2016, p. 9-13 Wataru Nakajima, "Current Status of Electrical Equipment Deterioration Diagnosis Technology", Journal of Electrical Equipment Society, Vol. 32 No. 12, General Incorporated Association Electrical Equipment Society, December 2012, p. 893-896 Iwao Oshima, 2 outsiders, "Electrical Insulation Phenomenon at the Time of Contamination / Wetness and Countermeasures", Electrical Calculation, February 1988, Denki Shoin Co., Ltd., 1988, p. 79-85 IEEJ Technical Report (334), February 1990 issue, Institute of Electrical Engineers of Japan, May 1990 Tatsuo Kawamura, Katsuo Isaka, "Analysis of Moisture Absorption, Leakage Current and Flashover Characteristics of Dirty Surfaces by Model", Production Research, Vol. 21, No. 7, Institute of Industrial Science, University of Tokyo, July 1969, p. 446-447

For the measurement or analysis of equivalent salt adhesion density and adhered ions, which are indicators of the degree of fouling, the deposits deposited on the insulator are wiped off, and the wiped deposits are analyzed (specifically, the measurement of electrical conductivity and ions). It is done by chromatograph etc.). Wiping off deposits on insulation is not practical as it requires the equipment to be shut down for safety reasons. Further, the equivalent salt adhesion density is obtained from the measurement of the electric conductivity, and the analysis of the adhered ions is analyzed by using an ion chromatograph or the like, so that it takes time and cost.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for easily estimating or evaluating a temporary decrease in insulation resistance value of an insulator or recovery from a reduced state.

One aspect of the method for evaluating the decrease in the insulation resistance value of the insulator of the present invention that achieves the above object or the recovery from the reduced state is
It is a method of evaluating the decrease or recovery from the decrease in the insulation resistance value of the insulator provided in the equipment.
The average amount of airborne dust, which is the average value of the amount of airborne dust in the space provided with the insulator for a predetermined period, is measured in advance.
The average amount of suspended dust, the operating time of the device, and the average amount of suspended dust and the average floating amount, which are the average values of the amount of suspended dust in a space provided with the insulator of the device in advance in any device for a predetermined period of time. The degree of contamination of the insulator to be evaluated is calculated or estimated based on the equivalent salt adhesion density or correlation data with the adhered ions measured during the period when the amount of dust was calculated.
Insulation resistance of the insulator to be evaluated based on the calculated or estimated degree of fouling and the humidity measured by the device equipped with the insulation to be evaluated or the temperature and humidity measured by the device. Estimate the value
Based on the estimated insulation resistance value, it is characterized in that the temporary decrease in the insulation resistance value of the insulation to be evaluated or the recovery from the lowered state is evaluated.

In addition, another aspect of the method for evaluating the reduction or recovery from the reduced insulation resistance value of the insulating material of the present invention that achieves the above object is to reduce the insulation resistance value of the insulating material or recover from the lowered state. In the method of evaluation
If the device with the insulation to be evaluated has a fan
The average amount of airborne dust, which is the average value of the amount of airborne dust when the fan is stopped and when the fan is operated, is measured, and the average amount of airborne dust when the fan is stopped and when the fan is operated is proportional to the ratio of the operating time of the fan. It is characterized in that the average amount of airborne dust in a space provided with an insulator to be evaluated is calculated for a predetermined period.

In addition, one aspect of the apparatus for evaluating the decrease in the insulation resistance value of the insulator of the present invention that achieves the above object or the recovery from the reduced state is
It is a device that evaluates the decrease in the insulation resistance value of the insulation provided in the equipment or the recovery from the reduced state.
The degree of contamination for which the insulation is calculated or estimated based on the average amount of airborne dust, which is the average value of the amount of airborne dust for a predetermined period of the space provided with the insulation, and the operating time of the equipment. Estimator and
The insulation resistance value of the insulation is estimated and estimated based on the degree of pollution calculated or estimated by the degree of fouling estimation unit and the degree of fouling measured by the device or the temperature and humidity measured by the device. It is provided with an estimated insulation resistance value fluctuation evaluation unit that evaluates a temporary decrease in the insulation resistance value of the insulator or recovery from the reduced state based on the obtained insulation resistance value.
The fouling degree estimation unit is the average floating dust amount which is an average value of the floating dust amount in a predetermined period, which is obtained in advance by an arbitrary device, and the equivalent salt adhesion density or the equivalent salt adhesion density in the period when the average floating dust amount is calculated. It is characterized in that it includes correlation data with adhered ions, and calculates or estimates the degree of contamination of the insulator based on the interphase data.

In addition, another aspect of the apparatus for evaluating the reduction or recovery from the reduced insulation resistance value of the insulating material of the present invention that achieves the above object is to reduce or recover the insulating resistance value of the insulating material. In the device to be evaluated
It is characterized in that it is provided with an alarm output unit that outputs an alarm according to the evaluation of the estimated insulation resistance value fluctuation evaluation unit.

In addition, another aspect of the apparatus for evaluating the reduction or recovery from the reduced insulation resistance value of the insulating material of the present invention that achieves the above object is to reduce or recover the insulating resistance value of the insulating material. In the device to be evaluated
It is characterized in that it is provided with an improvement unit for improving the decrease in the insulation resistance value of the insulator according to the evaluation of the estimated insulation resistance value fluctuation evaluation unit.

According to the above invention, it is possible to easily estimate or evaluate the temporary decrease in the insulation resistance value of the insulator or the recovery from the reduced state.

It is the schematic of the apparatus which evaluates the decrease or the recovery from the decrease state of the insulation resistance value of the insulator which concerns on embodiment of this invention. It is a figure which shows the correlation of the annual average airborne dust amount and the annual equivalent salt adhesion density. It is a figure which shows the relationship between the equivalent salt adhesion density with respect to a relative humidity, and a leakage current. It is a block diagram explaining the method of evaluating the reduction of the insulation resistance value of the insulator which concerns on embodiment of this invention, or the recovery from the lowered state. It is an external view of the device to be monitored. It is a top view of the simulated insulation plate arranged in the equipment to be monitored. It is a figure explaining the outline of the dust meter. It is a figure which shows the difference of the floating dust amount by the difference of the measurement day. It is a figure which shows the transition of the integrated value of the amount of suspended dust. It is a figure which shows the transition of the equivalent salt adhesion density. (A) It is a figure which shows the transition of the adhering ion in a high-voltage power receiving board, (b) is a figure which shows the transition of the adhering ion in a lamp transformer board. (A) It is a figure which shows the transition of the floating dust amount (1 minute value) in a central substation and the integrated amount, and (b) is the figure which shows the floating dust amount (1 minute value) and the integrated amount in an electric room. It is a figure which shows the time change of relative humidity and temperature, and the possibility of dew condensation in this change. It is a figure which shows the relationship between the relative humidity and the partial discharge extinction voltage by the difference of the equivalent salt adhesion density. It is a figure which shows the relationship between a relative humidity and a leakage current (leakage current characteristic of a 6kV epoxy insulator (DC16kV application (7 minutes value), temperature: 30 degreeC)) by the difference of the equivalent salt adhesion density.

A method and an apparatus for evaluating a decrease in the insulation resistance value of an insulator according to an embodiment of the present invention or a recovery from the reduced state will be described in detail with reference to the drawings.

As shown in FIG. 1, a device 1 (hereinafter referred to as an insulation resistance value evaluation device 1) for evaluating a decrease in the insulation resistance value of an insulator according to an embodiment of the present invention or a recovery from the reduced state is an estimation of the degree of fouling. A unit 2, an estimated insulation resistance value fluctuation evaluation unit 3, and a control unit 4 are provided. The insulation resistance value evaluation device 1 is provided in, for example, a device to be monitored, such as a power receiving / transforming facility. Then, the temporary insulation resistance value due to stains on the insulation (for example, insulators, floors, etc.) provided in the equipment to be monitored, increase in humidity, dew condensation on the insulation (dew point temperature and insulation surface temperature), etc. Estimate and evaluate (or monitor) the decrease in the insulation resistance value of the insulator or the recovery from the reduced state based on the estimated insulation resistance value.

The fouling degree estimation unit 2 calculates the fouling degree (for example, equivalent salt adhesion density, adhered ions, etc.) from the average value of the amount of suspended dust for a predetermined time (hereinafter referred to as the average amount of suspended dust) and the operating time of the device to be monitored. Calculate or estimate. The operating time of the device to be monitored is the operating time from the initial operation of the device to be monitored or the elapsed time from the cleaning and inspection of the insulation surface of the device to be monitored.

The fouling degree estimation unit 2 includes an average amount of airborne dust in a space provided with an insulator to be monitored, an average amount of airborne dust measured by an arbitrary device for a predetermined time, and a degree of fouling accumulated in the predetermined time. Correlation data showing the relationship between the two is stored. Then, based on this correlation data, the degree of pollution is derived from the average amount of suspended dust measured in the device to be monitored. Specifically, the average amount of suspended dust is converted into the degree of fouling based on the correlation data, and the degree of fouling is calculated or estimated by the product of the converted degree of fouling and the operating time of the equipment to be monitored.

The average amount of airborne dust in the equipment to be monitored is determined by measuring the amount of airborne dust several times (3 to 4 times) each season with, for example, a light scattering type digital dust meter, and based on the measured amount of airborne dust. The annual average amount of suspended dust is calculated. As will be described in detail later, when the equipment to be monitored is equipped with an intake fan or an exhaust fan, the average amount of airborne dust when the fan is running and when the fan is stopped is measured, and the average amount of dust floating is measured from the fan operating frequency per year. The average amount of suspended dust is calculated.

The correlation data between the average airborne dust amount and the degree of fouling in any equipment is, for example, the correlation data as shown in FIG. 2 by measuring the annual average airborne dust amount and the annual average equivalent salt adhesion density in any equipment in advance. Is required as. For the annual average airborne dust amount, for example, the airborne dust amount is measured several times each season with a dust meter, and the annual average airborne dust amount is calculated based on the measured airborne dust amount. For the annual equivalent salt adhesion density, for example, the equivalent salt amount is calculated from the intrinsic resistance value and volume of the water by dissolving the sediment accumulated in one year in water (resistance method).

The estimated insulation resistance value fluctuation evaluation unit 3 estimates the insulation resistance value of the insulator based on the stain degree calculated by the stain degree estimation unit 2 and the relative humidity of the space where the insulation to be monitored is provided. , Evaluate the decrease in the insulation resistance value of the insulator or the recovery from the reduced state. The estimated insulation resistance value fluctuation evaluation unit 3 stores, for example, data showing the correlation between the equivalent salt adhesion density and the leakage current (or insulation resistance value) as shown in FIG. Then, the leakage current (insulation resistance value calculated from the leakage current) is estimated based on this interphase data and the input (relative humidity) from the temperature / humidity sensor (not shown), and this leakage current (or insulation resistance value). Evaluate the decrease in the insulation resistance value of the insulation or the recovery from the reduced state by the estimation of. The threshold value of the leakage current and the insulation resistance value is determined according to the rating of the device provided with the insulator to be monitored. Further, the estimated insulation resistance value fluctuation evaluation unit 3 can also set the classification of the pollution level of the equipment to be monitored based on the pollution degree calculated or estimated by the pollution degree estimation unit 2.

The control unit 4 outputs a signal for outputting an alarm for a decrease in the insulation resistance value to an alarm output device (not shown) in response to the decrease in the insulation resistance value of the insulator estimated by the estimated insulation resistance value fluctuation evaluation unit 3. , Outputs a start signal of another device (for example, a device that raises the temperature (lowers the humidity) of the space where the insulation is provided) that improves the decrease in the insulation resistance value. When the insulation resistance value of the insulator recovers from the lowered state, a signal for stopping the alarm for the decrease in the insulation resistance value is output, or a stop signal for another device for improving the decrease in the insulation resistance value is output. Or something. The control unit 4 corresponds to a stain level detection unit 8 and an insulation resistance value decrease detection unit 9, which will be described in detail later.

The method of evaluating the decrease in the insulation resistance value or the recovery from the reduced state in the insulation resistance value evaluation device 1 will be described in more detail with reference to the block diagram of FIG. The average airborne dust amount will be described by way of example when the annual average amount is calculated, but the period for calculating the average airborne dust amount can be set to any period.

The temperature detection value of the temperature detection unit 5, the humidity detection value of the humidity detection unit 6, and the airborne dust amount of the airborne dust amount detector 7 (average airborne dust amount after averaging) are input to the insulation resistance value evaluation device 1. Will be done. The average amount of airborne dust of the airborne dust amount detector 7 is the amount of airborne dust detected by the airborne dust amount detector 7 even in the embodiment in which the data measured in advance is stored in the insulation resistance value evaluation device 1. The mode may be such that the averaging process is performed and the data is input to the insulation resistance value evaluation device 1.

In the insulation resistance value evaluation device 1, the annual average airborne dust measured by the device to be monitored based on the correlation data between the annual average airborne dust amount and the annual equivalent salt adhesion density (fouling degree) as shown in FIG. The equivalent salt adhesion density (fouling degree) is estimated from the amount and the operating time of the equipment to be monitored. Specifically, the annual average airborne dust amount is converted into the annual equivalent salt adhesion density, and the equivalent salt adhesion density in the equipment is estimated (or calculated) based on the operating time of the equipment.

Further, the insulation resistance value evaluation device 1 estimates the leakage current and the insulation resistance value based on the input temperature detection value and humidity detection value and the estimated annual equivalent salt adhesion density (fouling degree). The leakage current and the insulation resistance value are estimated based on, for example, the correlation data shown in FIG.

The equivalent salt adhesion density (fouling degree) estimated by the insulation resistance value evaluation device 1 is transmitted to the fouling level detection unit 8. The fouling level detection unit 8 detects the fouling level based on a preset threshold value and sets the fouling level of the device. Note that different alarms may be output depending on the level of contamination of the device. Table 1 shows an example of the pollution level according to the degree of pollution.

Further, the leakage current and the insulation resistance value estimated by the insulation resistance value evaluation device 1 are transmitted to the insulation resistance value reduction detection unit 9. The insulation resistance value decrease detection unit 9 detects a decrease in the insulation resistance value of the insulator based on a preset threshold value, and if this is detected, transmits a signal for outputting an alarm. Further, when a decrease in the insulation resistance value is detected, a signal for driving a means (heater or the like) for improving the decrease in the insulation resistance value can be transmitted.

Even if the insulation resistance value of the insulator temporarily decreases, if the humidity decreases and the dew point temperature decreases, the leakage current naturally decreases and the insulation resistance value increases. Therefore, when the insulation resistance value reduction detection unit 9 recovers from the reduced insulation resistance value, it estimates that the insulation resistance value has recovered from the lowered state and transmits a signal to stop the alarm output. It sends a signal to stop the means for improving the decrease in insulation resistance value.

In this way, an alarm is output (or stopped) according to the detection results of the fouling level detection unit 8 and the insulation resistance value decrease detection unit 9, and a device for responding to the decrease in the insulation resistance value is driven (or or stopped). By stopping), it is possible to determine whether or not cleaning is necessary and whether or not there is a risk of dielectric breakdown due to a decrease in the insulation resistance value during maintenance or in real time. The fouling level detection unit 8 and the insulation resistance value decrease detection unit 9 can be provided either inside or outside the insulation resistance value evaluation device 1.

According to the method for evaluating the decrease in the insulation resistance value of the insulator according to the embodiment of the present invention or the recovery from the reduced state and the insulation resistance value evaluation device 1, a predetermined period of time in the device to be monitored. If the average amount of airborne dust is known, it is possible to determine the temporary decrease in the insulation resistance value of the insulation or the recovery from the lowered state in consideration of the degree of contamination of the insulation by monitoring the temperature and humidity. As a result, the insulation resistance value of the insulator is constantly estimated or monitored, and an alarm is output (or stopped) according to the estimated insulation resistance value (fouling level), or the decrease in the insulation resistance value is improved. A drive (or stop) signal can be output.

That is, by measuring the level of dust suspended in the air, the equivalent salt adhesion density on the surface of the insulation can be derived, and the temperature and humidity data measured by the device to be monitored will temporarily reduce the insulation resistance of the insulation. Alternatively, recovery from a degraded state can be evaluated (or monitored).

In addition, by measuring the average amount of airborne dust in the equipment to be monitored in advance, the environment in which the equipment to be monitored is placed can be determined, and it is possible to propose environmental improvement. In addition, it is possible to predict the insulation deterioration of the insulator and output an alarm based on this prediction, using the annual average airborne dust amount and the annual pollution level as constants.

In addition, since the annual fouling level (for example, equivalent salt adhesion density) can be predicted according to the operating time of the equipment to be monitored, the cleaning cycle for reducing the fouling level becomes clear. That is, maintenance can be performed according to the condition of the device to be monitored.

Further, according to the method for evaluating the decrease in the insulation resistance value of the insulator according to the embodiment of the present invention or the recovery from the reduced state and the insulation resistance value evaluation device 1, in any device as shown in FIG. Since the pollution degree is estimated from the average floating dust amount of the equipment to be monitored based on the correlation data between the average airborne dust amount for the obtained predetermined period and the pollution degree (equivalent salt adhesion density), the equipment The degree of fouling can be estimated regardless of the difference in equipment such as the difference and the presence or absence of a fan. In other words, the average amount of airborne dust is smaller in the closed type board, and the average amount of airborne dust is larger in the JIS board, which is easy for outside air to enter. Can be evaluated as a difference. As a result, the degree of fouling can be easily estimated according to the operating time of the device to be monitored regardless of the difference in the device to be monitored.

Further, since the amount of suspended dust can be spot-measured with a commercially available dust meter, the average amount of suspended dust can be easily calculated by measuring several times a year.

[Verification test]
A verification test of the insulation resistance value evaluation device 1 according to the embodiment of the present invention was conducted. The verification test was carried out by installing a temperature / humidity sensor and a simulated insulating plate (polyester premix) in an outdoor JIS cubicle, which is a power receiving / transforming facility as shown in FIG. Then, the temperature and humidity inside the panel, the temperature of the surface of the simulated insulating plate (difference from the dew point temperature), the transition of the degree of contamination, and the amount of suspended dust are measured, and the difference between the temperature and humidity outside the panel and the temperature and humidity inside the panel, and the surface of the insulator The relationship between the temperature difference, the change in the degree of fouling, and the amount of suspended dust was investigated.

A simulated insulating plate as shown in Fig. 6 is installed in the cubicle (high-voltage power receiving board and lamp transformer board), and the equivalent salt adhesion density and suspended dust are installed every month (the standard measurement date is ± 5 days). The amount was measured. The simulated insulating plate was provided near the floor in the cubicle, and the degree of contamination of the floor surface was simulated. In addition, the ambient temperature and humidity of the simulated insulating plate, the surface temperature of the simulated insulating plate, and the external temperature and humidity were measured, and the history was recorded. The temperature / humidity data was measured every 10 minutes, which is the same frequency as the measurement frequency of the Japan Meteorological Agency, and the temperature / humidity data was collected every month.

The temperature / humidity history was measured using a temperature / humidity logger manufactured by Syscom (MSHT-16-V4). As the temperature / humidity sensor, a digital temperature / humidity sensor (K type thermocouple) manufactured by IST was used. The thermocouple was provided in one section of the simulated insulating plate (the part ○ in the lower right of FIG. 6).

The amount of airborne dust was measured by measuring the amount of airborne dust for 10 minutes using a light scattering type digital dust meter (MODEL-3442) manufactured by Nippon Kanomax Co., Ltd., and calculating the average value per minute. This dust meter measures the amount of suspended dust by utilizing the fact that the intensity of scattered light when light is applied to suspended particles in the air is proportional to the dust concentration. As shown in FIG. 7, the sample air containing suspended dust is sucked in, the intensity of the scattered light generated by irradiating the laser beam is converted into an electric signal by a photodiode (detector), and integrated as a count value (CPM value). bottom. The count value per minute was converted to ^{relative mass (mg / m 3} ) by the K value (mass concentration conversion coefficient). The K value in a typical place is 0.003.

As shown in FIG. 8, the amount of suspended dust was affected by the outside air and changed significantly depending on the environment on the measurement day. However, as shown in FIG. 9, when the amount of suspended dust was evaluated by the integrated value throughout the year, the integrated value of the amount of suspended dust changed almost linearly. From this, it is considered that the dust level inside the cubicle can be estimated by measuring the amount of suspended dust about four times each season and obtaining the integrated value.

FIG. 10 is a graph showing the transition of the equivalent salt adhesion density in the high-voltage power receiving board and the lamp transformer board. The floor area for measuring the amount of suspended dust (that is, one section of the simulated insulating plate) is the same, but the equivalent salt adhesion density (fouling level) of the lamp transformer panel is almost double the equivalent salt adhesion density of the high-voltage power receiving panel. It became. It is considered that this is because the fan is installed in the upper part of the lamp transformer panel, so that the dust inside the cubicle is concentrated here and the dust of heavy particles is accumulated in the upper part of the insulator.

FIG. 11 is a graph showing the transition of adhered ions in the high-voltage power receiving board and the lamp transformer board. The transition of attached ions also showed the same tendency as the equivalent salt adhesion density.

From this, the integrated value of the amount of suspended dust (that is, the product of the average amount of suspended dust for a predetermined period in the device to be monitored and the operating time of the device to be monitored) and the degree of fouling (equivalent salt adhesion density and adhered ions). Etc.) are considered to have a certain correlation. Therefore, the average amount of airborne dust can be converted into the degree of pollution by obtaining the correlation between the average amount of airborne dust and the degree of fouling in a predetermined period in advance.

FIG. 12 shows the results of measuring the amount of suspended dust in the central substation and the S5 electric room where the outside air introduction fan is located. There was a 1.5 to 2 times difference in the amount of airborne dust between when the fan was running and when it was stopped. However, immediately after the fan was operated, the amount of suspended dust was about 3 times and 6 times that when the fan was stopped. It is considered that the rate of increase in the amount of suspended dust due to the operation of the fan changes depending on the volume of the equipment and the capacity of the fan. However, the transition of the integrated value of the floating dust amount changes almost linearly regardless of whether the fan is running or stopped, and even if the fan is equipped, the pollution level is changed from the integrated value of the floating dust amount. It is thought that it can be guessed. In this case, the average amount of suspended dust is calculated according to the operating frequency (ratio of operating time and stopping time) of the fan.

Figure 2 shows the annual average amount of suspended dust and the annual equivalent salt adhesion density (1) from the data (25 locations) measured by different devices over two years, except for special conditions such as outdoor cubicles and continuous operation of the cooling fan inside the panel. It is a graph of the relationship with the annual pollution increase level).

There was a correlation (error ± 15%) between the annual average airborne dust amount and the annual equivalent salt adhesion density. From this, the amount of airborne dust is measured several times a year (about 4 to 5 times) to obtain the annual average amount of airborne dust, and the annual equivalent salt adhesion density is converted to the annual equivalent salt adhesion density based on the correlation shown in FIG. It is considered that the change in the degree of fouling (error ± 15%) in 1 year can be estimated. Since the data in FIG. 2 includes data in which the cleaning execution time is not accurate, data with a large error is included, but the coefficient of determination of the approximate curve (R ^{2) regardless of the measured location.} ) Was 0.7 or more. From this, it is considered that the average amount of suspended dust can be converted into the equivalent salt adhesion density with a certain accuracy regardless of the equipment based on this correlation.

That is, by obtaining the relationship between the average airborne dust amount for a predetermined period and the equivalent salt adhesion density, adhered ions, etc. in advance with an arbitrary device, the equivalent salt adhesion is obtained from the average airborne dust amount and the operating time of the device to be monitored. The density and the like (accumulated contaminants) can be estimated. Therefore, the pollution level adhering to the insulator at any time is estimated based on the time of cleaning, the equivalent salt adhesion density at the time of cleaning (can be set to 0), and the average amount of suspended dust. be able to. For example, based on the function (E = αe ^(βS) , E: equivalent salt adhesion density, S: average airborne dust amount, α, β: constant) derived from the characteristic diagram of FIG. 2, from the annual average airborne dust amount. The annual equivalent salt adhesion density can be calculated.

The method and apparatus for evaluating the decrease in the insulation resistance value of the insulator of the present invention or the recovery from the reduced state have been described above by showing a specific embodiment. The method and apparatus for evaluating the recovery from the lowered state are not limited to the embodiments, and the design can be appropriately changed as long as the characteristics are not impaired. It belongs to the range.

For example, as shown in FIG. 13, a threshold value (for example, 2 ° C.) is set for the difference between the surface temperature and the dew point temperature of the insulator, and the insulation resistance of the insulator is based on the difference between the surface temperature and the dew point temperature of the insulator. It is also possible to evaluate the decrease in value or the recovery from the decreased state. In this case, the type of alarm can be changed according to the pollution classification shown in Table 1. For example, an alarm may not be issued in a lightly polluted area, and an alarm may be issued after a medium-polluted area. When monitoring the temperature difference between the dew point obtained from the temperature and humidity and the surface of the insulator (an insulator with a large heat capacity changes with a delay of about 10% with respect to a change in the ambient temperature of the insulator), for example, this temperature difference Condensation begins when the temperature drops below 2 ° C. Normally, as the temperature rises, the relative humidity decreases if the amount of moisture in the air is the same (the absolute humidity is the same). However, even if the ambient temperature of the insulator rises, the rise of the surface temperature of the insulator is delayed by about 10%, so that the surface temperature of the insulator does not rise, and if it remains low, the saturated water vapor amount exceeds the saturated water vapor amount on the surface of the insulator. Condensation will occur in this state.

Further, the measurement (location, number of times) of the amount of suspended dust and the like is not limited to the embodiment, and it is considered that the accuracy is improved as the amount is increased.

Further, in the description of the embodiment, the insulation resistance value of the insulator is estimated based on the integrated value of the average suspended dust amount and the equivalent salt adhesion density, but it is not only the equivalent salt adhesion density but also the average suspended dust amount. If there is a correlation factor, the insulation resistance value of the insulator is estimated based on the adhered ions, etc., and the decrease in the insulation resistance value of the insulator or the recovery from the lowered state is evaluated based on the estimated insulation resistance value. You can also do it.

1 ... A device that evaluates the decrease in the insulation resistance value of an insulator or the recovery from the reduced state (insulation resistance value evaluation device).
2 ... Stain degree estimation unit 3 ... Estimated insulation resistance value fluctuation evaluation unit 4 ... Control unit 5 ... Temperature detection unit 6 ... Humidity detection unit 7 ... Floating dust amount detector 8 ... Stain level detection unit 9 ... Insulation resistance value decrease detection unit (Alarm output section, improvement section)

Claims (4)

It is a method of evaluating the decrease or recovery from the decrease in the insulation resistance value of the insulator provided in the equipment.
The average amount of airborne dust, which is the average value of the amount of airborne dust in the space provided with the insulator for a predetermined period, is measured in advance.
The average amount of suspended dust, the operating time of the device, and the average amount of suspended dust and the average floating amount, which are the average values of the amount of suspended dust in a space provided with the insulator of the device in advance in any device for a predetermined period of time. The degree of contamination of the insulator to be evaluated is calculated or estimated based on the equivalent salt adhesion density or correlation data with the adhered ions measured during the period when the amount of dust was calculated.
Insulation resistance of the insulator to be evaluated based on the calculated or estimated degree of fouling and the humidity measured by the device equipped with the insulation to be evaluated or the temperature and humidity measured by the device. Estimate the value
Based on the estimated insulation resistance value, the temporary decrease in insulation resistance value of the insulation to be evaluated or the recovery from the reduced state is evaluated .
If it is evaluated insulator is provided apparatus comprises a fan,
The average amount of airborne dust, which is the average value of the amount of airborne dust when the fan is stopped and when the fan is operated, is measured, and the average amount of airborne dust when the fan is stopped and when the fan is operated is proportional to the ratio of the operating time of the fan. A method for evaluating a decrease in the insulation resistance value of an insulator or a recovery from a reduced state, which comprises calculating the average amount of suspended dust in a space provided with an insulator to be evaluated for a predetermined period. It is a device that evaluates the decrease in the insulation resistance value of the insulation provided in the equipment or the recovery from the reduced state.
The degree of contamination for which the insulation is calculated or estimated based on the average amount of airborne dust, which is the average value of the amount of airborne dust for a predetermined period of the space provided with the insulation, and the operating time of the equipment. Estimator and
The insulation resistance value of the insulation is estimated and estimated based on the degree of pollution calculated or estimated by the degree of fouling estimation unit and the degree of fouling measured by the device or the temperature and humidity measured by the device. It is provided with an estimated insulation resistance value fluctuation evaluation unit that evaluates a temporary decrease in the insulation resistance value of the insulator or recovery from the reduced state based on the obtained insulation resistance value.
The fouling degree estimation unit is the average floating dust amount which is an average value of the floating dust amount in a predetermined period, which is obtained in advance by an arbitrary device, and the equivalent salt adhesion density or the equivalent salt adhesion density in the period when the average floating dust amount is calculated. It is provided with correlation data with adhered ions, and the degree of contamination of the insulator is calculated or estimated based on this interphase data .
If it is evaluated insulator is provided apparatus comprises a fan,
The average amount of airborne dust, which is the average value of the amount of airborne dust when the fan is stopped and when the fan is operated, is measured, and the average amount of airborne dust when the fan is stopped and when the fan is operated is proportional to the ratio of the operating time of the fan. A device for evaluating a decrease in the insulation resistance value of an insulator or a recovery from a reduced state, which is characterized by calculating the average amount of suspended dust in a space provided with an insulator to be evaluated for a predetermined period. The decrease in the insulation resistance value of the insulator according to claim 2 , or the recovery from the reduced state, is provided with an alarm output unit that outputs an alarm according to the evaluation of the estimated insulation resistance value fluctuation evaluation unit. A device to evaluate. The insulator according to claim 2 or 3 , further comprising an improvement unit for improving the decrease in the insulation resistance value of the insulator according to the evaluation of the estimated insulation resistance value fluctuation evaluation unit. A device that evaluates a decrease in insulation resistance or recovery from a reduced state.

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