JP7056124B2 - Deterioration diagnosis method and deterioration diagnosis device for insulation - Google Patents

Description

The present invention relates to a deterioration diagnosis method and a deterioration diagnosis device for an insulating material.

A high-voltage power receiving and distributing device is a device in which a high-voltage structure is stored in a board of a certain size. In places where the potential difference is large inside the switchboard, a predetermined dielectric strength is secured by separating the separation distance or sandwiching an insulator. If the insulation performance of an insulating material deteriorates due to long-term use, the insulation will eventually break down and lead to a failure. Therefore, there is a demand for a deterioration diagnosis technique for an insulating material that prevents the failure.

By the way, environmental conditions (particularly humidity) have a great influence on the progress process of insulation deterioration. Therefore, even if there is no insulation abnormality in the measurement environment, there is a risk that deterioration will progress under high humidity conditions. Therefore, in recent years, various methods for estimating and measuring the resistance value of the surface of an insulator under high humidity conditions have been proposed.

The invention described in Patent Document 1 proposes a reference value that "the surface resistance value in a high humidity state is ¹⁰⁶ Ω or less" as a life determination.

Further, in the invention described in Patent Document 2, it is stated that the degree of deterioration of the insulating material can be determined by (the number of digits of the low humidity insulation resistance value) / (the number of digits of the high humidity insulation resistance value).

Further, in the invention described in Patent Document 3, the standard of "less than or equal to the surface resistance value estimated from the equivalent circuit model along the insulation surface" is shown as the life determination. The lifetime condition is defined as the condition in which a dry band can be discharged if it is generated.

Japanese Unexamined Patent Publication No. 2000-356660 Japanese Unexamined Patent Publication No. 2015-227804 Japanese Unexamined Patent Publication No. 2005-61901

However, in the invention described in Patent Document 1, although the criterion for determining the life is clear and simple, the basis of the criterion is not shown. Therefore, it is difficult to determine the life with high accuracy.

Further, in the invention described in Patent Document 2, although the criterion for determining the life is clear, it is not quantified and merely shows the humidity dependence of the surface of the insulator. That is, the basis for determining the life state from the humidity dependence of the surface of the insulator has not been shown, and it is difficult to determine the life state with high accuracy.

Further, in the invention described in Patent Document 3, since the capacitance component which is the equivalent circuit constant of the proposed equivalent circuit model depends on the material and the shape, the capacitance component cannot be easily obtained (). The high humidity surface resistance of the dry band is close to infinity). Therefore, it is difficult to easily determine the life by the method of Patent Document 3.

The present invention has been made in view of these problems, and in particular, to provide a deterioration diagnosis method and a deterioration diagnosis device capable of performing deterioration diagnosis of an insulating material easily and with high accuracy. The purpose.

INDUSTRIAL APPLICABILITY The present invention is a deterioration diagnosis method for diagnosing a deterioration state of an insulator used in a high-voltage power receiving and distribution device, in which the surface resistance ratio between a low resistance band and a high resistance band on the surface of the insulation and the creeping insulation of the insulation. Based on the length and the creepage potential difference generated along the creepage of the insulation, the relational curve between the gap length of the high resistance band and the generated voltage on the creeping surface of the insulation is obtained, and the relational curve and the gap length are obtained. It is characterized in that the deterioration state of the insulating material is determined by comparing with a reference curve showing the relationship with the discharge voltage, and the passage curve is used as the reference curve .

In the deterioration diagnosis method of the present invention, it is preferable to determine the deterioration state of the insulation based on the presence or absence of an intersection between the relational curve and the reference curve.

Further, in the deterioration diagnosis method of the present invention, it is preferable to determine the surface resistivity of the surface of the insulator with or without contamination as the surface resistivity ratio of the low resistance band and the high resistance band.

Further, in the deterioration diagnosis method of the present invention, the surface resistance value in the state where the stain is deposited is the surface resistance value before cleaning the surface of the insulator, and the surface resistance value in the state where the stain is not deposited is set. The surface resistance ratio can be obtained by using the surface resistance values after cleaning the surface of the insulating material.

Further, in the deterioration diagnosis method of the present invention, the surface resistance value at the time of shipment is the surface resistance value without the stain accumulation, and the surface resistance value at the present time is the surface resistance value with the stain accumulation. The surface resistance value can be obtained by using each value.

Further, in the deterioration diagnosis method of the present invention, the insulation design dimensional value of various product standards may be used as the creepage insulation length of the insulator, and the normal ground voltage may be used as the creepage potential difference generated along the creepage of the insulator. can.

Further, in the deterioration diagnosis method of the present invention, the surface resistivity of the 6 kV model is 150 or more and the surface resistivity of the 3 kV model is 230 or more based on the comparison between the relational curve and the reference curve. It can be determined that the product has reached the end of its useful life or requires cleaning.

Further, according to the present invention, in a deterioration diagnosis device for diagnosing a deterioration state of an insulator used in a high-voltage power receiving and distribution device, a surface resistance value in the presence or absence of fouling accumulation of the insulation, a creeping insulation length of the insulation, and the insulation thereof. Based on the input unit for inputting the creepage potential difference generated along the creepage of an object, the surface resistance ratio between the low resistance band and the high resistance band on the surface of the insulator based on the surface resistance value, the creepage insulation length, and the creepage potential difference. The calculation unit for obtaining the relationship curve between the gap length and the generated voltage of the high resistance band on the surface of the insulation, the relationship curve, and the reference curve showing the relationship between the gap length and the discharge voltage. It is characterized by having a comparison unit for comparing the above and a diagnostic unit for diagnosing the deterioration state of the insulation based on the result of the comparison unit, and using a pastion curve as the reference curve .

According to the deterioration diagnosis method for an insulating material of the present invention, deterioration diagnosis can be performed easily and with high accuracy.

It is an example of the creepage structure of the insulator in this embodiment. This is an example of a soiled state along the surface of the insulator shown in FIG. It is an equivalent circuit model along the surface of the insulator shown in FIG. It is a table which shows the dimension standard (JEM) of the creeping insulation length. This is an example of the relationship curve between the gap length in the high resistance band and the generated voltage. It is a Paschen curve as an example of a reference curve of a gap length and a discharge voltage. This is an example of deterioration diagnosis comparing the relation curve and the Paschen curve. It is a flowchart of the deterioration diagnosis method of the insulator in this embodiment. It is a block diagram of the deterioration diagnosis apparatus in this embodiment. It is a graph which shows the relationship between the gap length of a high resistance band and the surface resistivity at the time of discharge generation.

Hereinafter, the deterioration diagnosis method and the deterioration diagnosis apparatus according to the embodiment of the present invention will be described in detail with reference to the attached drawings. The deterioration diagnosis method and the deterioration diagnosis device according to the present invention are not limited to the following embodiments, and can be variously modified and implemented within the scope of the purpose.

The object of deterioration diagnosis according to the present embodiment is a solid insulating material used for holding a high-voltage object constituting a high-voltage power receiving / distributing device or for a barrier. The solid insulator is, for example, a polyester resin, an epoxy resin, or the like. When the insulation performance of these insulators deteriorates due to long-term use, they eventually lead to dielectric breakdown failure. Therefore, there is a demand for a deterioration diagnosis technique for an insulating material that prevents failure.

In solid insulation, the bulk insulation performance that penetrates and breaks the inside of the insulation is very high, and the creepage insulation performance that breaks the surface of the insulation in a creeping manner becomes a problem. The general mechanism of creepage dielectric breakdown due to insulation deterioration is (1) dirty substances adhere to the surface of the insulator, (2) the polluted substances get wet and the surface resistance decreases, and (3) local high resistance band (high). The shared voltage rises in the resistance part), (4) minute discharge is generated due to voltage concentration, (5) the insulation surface is altered by the discharge decomposition product, and (6) (1) to (5) are repeated to generate a carbonized conductive path. , (7) The conduction path grows by repeating discharge at the tip of the carbonized conductive path, and (8) dielectric breakdown occurs. The local high resistance zone in (3) refers to, for example, the formation of a dry zone due to Joule heat and the residual unstained portion due to the adhesion of fibrous foreign matter.

In this embodiment, (3) is measured and deterioration diagnosis of the insulating material is performed. The deterioration diagnosis for (3) is also shown in Patent Document 3. That is, Patent Document 3 shows a standard of "less than or equal to the surface resistance value estimated from the equivalent circuit model along the insulation surface" as the life determination. However, Patent Document 3 requires a capacitance component that depends on the material and shape, and it is not possible to perform deterioration diagnosis easily and accurately.

Therefore, as a result of diligent research, the present inventor has invented a method for determining the life by assuming the worst condition as the shape of the insulator and using the actually measured surface resistance value.

Here, citing the equivalent circuit model of Patent Document 3 (see FIG. 8 of Patent Document 3), the smaller the capacitance component, the larger the burden voltage in the high resistance band. Therefore, as the worst condition, the shape of the insulator 1 is assumed to be a thin flat plate shape having a small capacitance as shown in FIG. 1A is a plan view of an insulator, and FIG. 1B is a cross-sectional view of the insulating portion shown in FIG. 1A cut along the line AA in the thickness direction and viewed from the direction of an arrow. As shown in FIGS. 1A and 1B, a pair of metal electrodes 2 and 3 having a creepage insulation length (distance between electrodes) L is provided on the surface 1a of the insulator 1. For example, the metal electrodes 2 and 3 are metal bolts and penetrate the thin plate-shaped insulator 1.

FIG. 2 is a deterioration mode on the surface 1a of the thin plate-shaped insulator 1 shown in FIG. As shown in FIG. 2, most of the creepage insulation length L is the low resistance band 4, and a deterioration mode in which the high resistance band 5 is generated only in the portion having a minute gap length g is assumed. The position and shape of the high resistance band 5 shown in FIG. 2 is an example. For example, the high resistance band 5 may be formed so as to surround the metal electrodes 2 and 3.

A phenomenon in which the low resistance band 4 and the high resistance band 5 shown in FIG. 2 are formed on the surface 1a of the insulation 1 due to the aged operation of the insulation 1 will be described. When the insulator 1 is used outdoors, the dust adhering to the surface 1a of the insulator 1 becomes wet due to rain or dew condensation. At this time, a local dry zone is generated by Joule heat due to the leakage current flowing through the wet layer of the surface 1a of the insulator 1. As a result, the wet layer occupying almost the entire surface of the surface 1a is the low resistance zone 4, and the local dry zone is the high resistance zone 5.

As another phenomenon, when used indoors, it is assumed that a portion where dust is accumulated on the surface 1a of the insulator 1 and a portion where dust is not accumulated due to a shield or a foreign substance. As the gap length at which this dust does not accumulate, it is assumed that the gap length crosses the surface 1a, for example, on the order of several hundred μm caused by hair or fibers. When exposed to a high humidity state in this state, the dust accumulation portion becomes a low resistance band 4 due to moisture absorption, while the dust non-accumulation portion becomes a high resistance zone 5.

When the state in which the high resistance band 5 having a minute gap length g is generated on the surface 1a of the low resistance band 4 shown in FIG. 2 is equivalently modeled, the resistance sharing circuit shown in FIG. 3 is obtained.

In this equivalent circuit, "crevice potential difference _VL ", "creepular insulation length L", "resistance value R _g in the high resistance band", "resistance value R _n in the low resistance band", and "gap length in the high resistance band". Using "g", the generated voltage (generated voltage) V _g applied to the gap length g in the high resistance band can be obtained by the following equation (1).

The following formula (2) can be obtained by rearranging the formula (1).

Here, with respect to the equation (2), the "crevice potential difference _VL " and the "creeping insulation length L" can be input from the specifications and dimensions of the target member.

The creepage potential difference _VL indicates the potential difference between the metal electrodes 2 and 3. Therefore, the creepage potential difference _VL can be read from the wiring diagram. As shown in FIG. 1, the creepage insulation length L is a linear distance between the metal electrodes 2 and 3.

Here, if the detailed dimensions of the creepage insulation length L are not known, the dimensions may be determined based on the product standard in which the target product is classified. In FIG. 4, "insulation distance of control equipment" of JEM1103 is shown as a reference standard. Based on the rated insulation voltage of the standard model shown in FIG. 4, the creepage distance, which is the creepage insulation length L, can be obtained.

The “surface resistance ratio R _g / R _n of the high resistance band and the low resistance band” is the ratio of the resistance value R _g of the high resistance band to the resistance value R _n of the low resistance band. In the formula (2), the surface resistivity ratio is R _n / R _g , which is the reciprocal of the surface resistivity ratio R _g / R _n . Here, since it is difficult to measure the resistance value R _g in the high resistance band and the resistance value R _n in the low resistance band, respectively, the surface resistivity ratio in the presence or absence of fouling accumulation is actually used as the surface resistivity R _g . It can be calculated as / R _n .

Specifically, using a measuring device equipped with a DC power supply equivalent to 1000 V such as a megger and a current mechanism, the surface resistance value with fouling deposits and the surface resistance value without fouling deposits under the same conditions. And each are measured. At this time, it is preferable to set a high humidity state (RH 95% or more) as the same condition.

For example, the surface resistance value measured before cleaning the surface 1a of the insulator 1 is the surface resistance value in a state where there is fouling accumulation, and the surface resistance value measured after cleaning the surface 1a of the insulator 1 is the fouling. The surface resistance value in the absence of deposition. Then, the “resistance value R _g in the high resistance band” can be evaluated as the surface resistance value measured before cleaning the surface 1a of the insulator 1. Further, the “resistance value R _n in the low resistance band” can be evaluated as the surface resistance value measured after cleaning the surface 1a of the insulator 1.

Alternatively, the surface resistance value at the time of shipment can be used as the surface resistance value without fouling accumulation, and the surface resistance value at present can be used as the surface resistance value with fouling accumulation. The “resistance value R _g in the high resistance band” can be evaluated as the surface resistance value at the present time. Further, the “resistance value R _n in the low resistance band” can be evaluated as the surface resistance value at the time of shipment. In this case, the surface resistance value at the time of shipment can be used for each deterioration diagnosis, and it is sufficient to measure the surface resistance value at the present time at the time of deterioration diagnosis.

When the creepage potential difference _VL , the creepage insulation length L, and the surface resistivity ratio R _n / R _g (the reciprocal of the surface resistivity R _g / R _n ) are substituted into the equation (2), the equation (2) becomes. It is a relational expression between the generated voltage V _g applied to the gap length g of the high resistance band and the gap length g of the high resistance band.

FIG. 5 is an example of a relational curve between the gap length _g and the generated voltage Vg. Here, FIG. 5 is a relational curve obtained assuming a three-phase 6 kV model. The creepage insulation length L was set to 90 mm in accordance with JEM1103. The creepage potential difference _VL was set to the normal ground voltage of 5.39 kVpeek (= 6.6 × 2 ^0.5 ÷ 3 ^0.5 ) assuming the distance between the energized part and the grounded part. Further, the relational curve in FIG. 5 was obtained with R _g / R _n = 150. As shown in FIG. 5, the longer the gap length g is, the larger the shared voltage becomes, and the generated voltage V _g becomes a curve having a tendency to saturate.

FIG. 6 is a reference curve of the gap length g and the discharge voltage. The reference curve shown in FIG. 6 is a Paschen curve showing the relationship between the gap length of the atmospheric pressure in which the atmospheric pressure is fixed to the atmospheric pressure and the air discharge voltage.

As shown in FIG. 6, the shorter the gap length g, the lower the voltage required for discharging tends to be. If the gap length g is further shortened to the level of several microns, a region where the decrease in the discharge voltage is contained appears, but this region is not targeted in the present embodiment.

The upper region of the Paschen curve shown in FIG. 6 shows the voltage at which discharge occurs, and the lower region shows the voltage at which discharge does not occur. Therefore, when the relationship curve between the gap length g and the generated voltage V _g shown in FIG. 5 is compared with the Paschen curve shown in FIG. 6, the presence or absence of an intersection between the two curves can be used to determine the presence or absence of discharge.

FIG. 7A is a result of comparing both curves when the surface resistivity ratio is R _g / R _n = 120. In FIG. 7A, both curves do not have an intersection. That is, the Paschen curve always has a voltage higher than the relational curve between the gap length g and the generated voltage V _g . In such a state, it can be determined that the insulation 1 has not reached the end of its life or it is not necessary to clean the insulation 1. On the other hand, FIG. 7B is a result of comparing both curves when the surface resistivity ratio R _g / R _n = 180. In FIG. 7B, both curves have intersections. Since it is shown that a discharge is generated when a high resistance band having a gap length g at the intersection is generated, it is determined that the insulation 1 has reached the end of its life or the insulation 1 needs to be cleaned. can.

(Deterioration diagnosis method)
FIG. 8 shows a flowchart of the deterioration diagnosis method of the present embodiment. In step ST1 of FIG. 8, the surface resistance value, the creepage insulation length, and the creepage potential difference in the presence or absence of fouling accumulation are acquired, and each value is input to the deterioration diagnosis device. Here, regarding the surface resistance value in the presence or absence of fouling accumulation, for example, the surface resistance value before cleaning the surface 1a of the insulator 1 and the surface resistance value after cleaning the surface 1a of the insulator 1 are measured, and each of them is measured. It is enough to enter the surface resistance value. At this time, it is preferable to measure each surface resistance value under the same conditions under a high humidity state (RH 95% or more). Alternatively, if the surface resistance value at the time of shipment is known, the surface resistance value at the present time is measured. If the surface resistance value at the time of shipment is already stored in the deterioration diagnosis device, only the current surface resistance value is measured and input. If the surface resistance value at the time of shipment is not stored in the deterioration diagnostic device, enter each surface resistance value. The current surface resistance value is preferably measured in a high humidity state (RH 95% or more). Further, if the measurement conditions of the surface resistance value at the time of shipment are known, the surface resistance value at the present time may be measured and the measurement conditions may be adjusted according to the conditions.

When it is difficult to measure the creepage insulation length and the creepage potential difference, the creepage insulation length (creeping distance) of the JEM standard shown in FIG. 4 and the normal ground voltage can be used.

In step ST2, the deterioration diagnosis device is used to determine the relationship curve between the gap length g and the generated voltage V _g as shown in FIG. 5 based on the surface resistivity R _g / R _n , the creepage insulation length L, and the creepage potential difference _VL . Calculate with.

Subsequently, in step ST3, the relational curve between the gap length _g and the generated voltage Vg is compared with the Paschen curve (the relational curve between the gap length and the discharge voltage in the atmospheric pressure state: see FIG. 6).

As a result of comparing both curves, if there is no intersection between the two curves as shown in FIG. 7A, it is diagnosed in step ST4 that the insulation 1 has not reached the end of its life or the insulation 1 does not need to be cleaned. To. Alternatively, as a result of comparing the two curves, when there is an intersection between the two curves as shown in FIG. 7B, it is determined that the insulation 1 has reached the end of its life or the insulation 1 needs to be cleaned in step ST4. Be diagnosed. Further, as shown in FIG. 7A, even when both curves do not have an intersection, it is possible to diagnose the remaining life based on, for example, the shortest distance between the two curves.

(Deterioration diagnostic equipment)
As shown in FIG. 9, the deterioration diagnosis device 10 of the present embodiment includes an input unit 11, a calculation unit 12, a comparison unit 13, a diagnosis unit 14, and a storage unit 15. The surface resistance value, the creepage insulation length, and the creepage potential difference depending on the presence or absence of fouling accumulation are input to the input unit 11. Further, the storage unit 15 stores the surface resistance value, the Paschen curve, and the like before shipment.

The calculation unit 12 calculates a relational curve (see FIG. 5) between the gap length _g and the generated voltage Vg based on the surface resistance value, the creepage insulation length, and the creepage potential difference input to the input unit 11.

The comparison unit 13 compares the relationship curve between the gap length _g and the generated voltage Vg calculated by the calculation unit 12 with the Paschen curve (see FIG. 7).

The diagnosis unit 14 makes a life determination, a cleaning determination, or a remaining life determination based on the comparison result by the comparison unit 13. As shown in FIG. 7, the lifespan judgment and the cleaning judgment can be judged by the presence or absence of an intersection when comparing the two curves. The remaining life determination can be derived from, for example, the shortest distance between the two curves in a state where the two curves do not have an intersection as shown in FIG. 7A.

According to the deterioration diagnosis method for the insulator 1 of the present embodiment described in detail above, deterioration diagnosis can be performed easily and with high accuracy. That is, in the present embodiment, the worst condition is assumed as the shape of the insulator 1, and the deterioration diagnosis is performed using the actually measured surface resistance value. In this way, the accuracy can be improved by assuming the worst conditions. Further, for example, deterioration diagnosis can be performed using the surface resistance values before and after cleaning and before and after shipment, and deterioration diagnosis can be easily performed.

Further, as described above, by performing the deterioration diagnosis using the surface resistance value before and after cleaning, the influence of the surface condition deterioration due to the aging use is reflected, and the deterioration diagnosis with higher accuracy becomes possible.

Further, by performing the deterioration diagnosis using the surface resistance values before and after shipment, the measurement work can be limited to the surface resistance measurement in the soiled state. Therefore, the cleaning work of the surface 1a of the insulator 1 becomes unnecessary, and a simpler deterioration diagnosis becomes possible.

Further, by setting the creepage insulation length and the creepage potential difference to fixed values by using the JEM standard shown in FIG. 4, the measurement of the creepage insulation length and the creepage potential difference becomes unnecessary, and the life can be determined more easily.

Further, in the present embodiment, the surface resistivity R _g / R _n , which is the life determination standard, can be specified from the normal ground voltage and the insulation dimension value of the JEM standard for the working voltage class. For example, Fig. 10 shows the relationship between the insulation dimension (creeping insulation length L) and the surface resistivity ratio R _g / R _n in the life state for the 6 kV model and the 3 kV model, which are standard in Japan. show. From FIG. 10, the surface resistivity ratio R _g / R _n ≈ 150 or more for the standard minimum insulation dimension of 90 mm for the 6 kV model or more, and the surface resistivity ratio R _g / R _n ≈ 230 or more for the standard minimum insulation dimension of 50 mm for the 3 kV model, respectively. It can be diagnosed as having reached the end of its useful life or requiring cleaning. In this way, by preserving the correspondence between the creepage insulation length L and the surface resistivity R _g / R _n that generate discharge for each voltage class, simpler deterioration diagnosis becomes possible.

Regarding the graph of FIG. 10, by comparing the relational curve and the Paschen curve, the correspondence value between the creepage insulation length L that causes the intersection and the surface resistivity R _g / R _n is saved as shown in FIG. 7B, and such correspondence is preserved. By obtaining a plurality of values, the graph shown in FIG. 10 can be generated. From FIG. 10, the correspondence between the creepage insulation length L that causes discharge and the surface resistivity ratio R _g / R _n can be seen. Therefore, by using FIG. 10, deterioration diagnosis can be performed without comparing the relational curve shown in FIG. 7 with the Paschen curve, and deterioration diagnosis can be easily performed.

The present invention is not limited to the above embodiment, and can be modified in various ways. The processing of the above-described embodiment is not limited to this, and can be appropriately changed within the range in which the effect of the present invention is exhibited. In addition, it can be appropriately modified and implemented as long as it does not deviate from the scope of the object of the present invention.

According to the deterioration diagnosis method of the present invention, there is an effect that deterioration diagnosis can be performed easily and with high accuracy, and in particular, it can be suitably used for diagnosis of insulation deterioration of high-voltage power receiving and distribution equipment.

1: Insulation 1a: Surface 2, 3: Metal electrode 4: Low resistance band 5: High resistance band 10: Deterioration diagnosis device 11: Input unit 12: Calculation unit 13: Comparison unit 14: Diagnosis unit 15: Storage unit L: Creeping insulation length g: Gap length

Claims (8)

In a deterioration diagnosis method for diagnosing the deterioration state of insulation used in high-voltage power receiving and distribution equipment,
The said on the surface of the insulator based on the surface resistance ratio between the low resistance band and the high resistance band on the surface of the insulator, the creepage insulation length of the insulator, and the creeping potential difference generated along the creeping surface of the insulator. Find the relationship curve between the gap length in the high resistance band and the generated voltage.
The deterioration state of the insulation is determined by comparing the relationship curve with the reference curve showing the relationship between the gap length and the discharge voltage.
A Paschen curve is used as the reference curve.
A method for diagnosing deterioration of an insulating material. The method for diagnosing deterioration of an insulator according to claim 1, wherein the deterioration state of the insulation is determined based on the presence or absence of an intersection between the relational curve and the reference curve. The deterioration diagnosis of the insulator according to claim 1 or 2, wherein the surface resistivity of the surface of the insulator with or without fouling accumulation is obtained as the surface resistivity ratio of the low resistance band and the high resistance band. Method. As the surface resistance value with the stain accumulation, the surface resistance value before cleaning the surface of the insulator, and as the surface resistance value without the stain accumulation, the surface resistance after cleaning the surface of the insulation. The method for diagnosing deterioration of an insulating material according to claim 3, wherein the surface resistivity ratio is obtained by using each value. The surface resistance value at the time of shipment is used as the surface resistance value without the stain accumulation, and the surface resistance value at the present time is used as the surface resistance value with the stain accumulation, respectively, to obtain the surface resistance value. The method for diagnosing deterioration of an insulator according to claim 3, wherein the method is characterized by the above. 5 . The method for diagnosing deterioration of an insulator according to any one. Based on the comparison between the relational curve and the reference curve, the surface resistivity of the 6 kV model is 150 or more, and the surface resistivity of the 3 kV model is 230 or more, and it is determined that the product has reached the end of its life or requires cleaning. The method for diagnosing deterioration of an insulator according to any one of claims 1 to 6 . In a deterioration diagnosis device that diagnoses the deterioration state of insulation used in high-voltage power receiving and distribution equipment.
An input unit for inputting the surface resistance value of the presence or absence of fouling accumulation of the insulation, the creepage insulation length of the insulation, and the creepage potential difference generated along the surface of the insulation.
The high resistance band on the surface of the insulator based on the surface resistance ratio between the low resistance band and the high resistance band on the surface of the insulator based on the surface resistance value, the creepage insulation length, and the creepage potential difference. The calculation unit that obtains the relational curve between the gap length and the generated voltage of
A comparison unit that compares the relationship curve with a reference curve showing the relationship between the gap length and the discharge voltage.
Based on the results of the comparison unit, the diagnostic unit that diagnoses the deterioration state of the insulation and
Have,
A Paschen curve is used as the reference curve.
Deterioration diagnostic equipment characterized by this.

Images