KR101581018B1 - Apparatus and method for diagnosing condenser bushing of transformer - Google Patents

Abstract

The present invention relates to an apparatus and a method for diagnosing a condenser bushing of a transformer. To this end, the present invention provides the apparatus for diagnosing the condenser bushing of the transformer, comprising: a detecting unit detecting a state diagnosis value including at least one among a total current value, a resistive current value and a partial discharge quantity generated from the condenser bushing when voltage is applied to the transformer; and a rate calculation unit comparing the state diagnosis value with a preset reference value to calculate a rate of the condenser bushing of the transformer, wherein the reference value is differently set for each diagnosis target transformer and includes at least one among two or more total current reference values having different value with respect to the total current value, two or more resistive current reference values having different values with respect to the resistive current value, and two or more partial reference values having different values with respect to the partial discharge value.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a capacitor bushing for a transformer,

The present invention relates to an apparatus and a method for diagnosing a condenser bushing of a transformer.

Recent breakdowns of transformers, for example, 765, 345, and 154kV transformers, except electrical and mechanical protection relay malfunctions and human errors, account for 40% of the failures caused by bushings. In addition, there are increasing tendencies such as a fire in the substation caused by the failure of the bushing, and a power outage due to the substation.

In other words, when electric field concentration phenomenon spreads due to foreign substances, sludge, manufacturing defect, moisture penetration, etc. in some places between insulating paper layers in a capacitor (insulating paper) for securing insulation between a transformer bushing main conductor and an enclosure Insulation breakdown will occur. Accordingly, there is an urgent need for a countermeasure by diagnosing the condition of the capacitor bushing.

At present, there are four methods of diagnosing the condition of the capacitor bushing: insulation deterioration, insulating oil gas analysis, sweep frequency response analysis (SFRA), and bushing test tap method. Of these techniques, insulation deterioration, insulating oil gas analysis, and SFRA method are only possible at the time of a breakdown, and diagnostic reliability is poor. In addition, the bushing test tap method has a problem in that it can be diagnosed even in the live state, but the diagnosis is performed without accurate reference value, and the reliability of the measured value is insufficient due to the conduction noise on the side of the proximal side and the external radiation noise exist.

In this regard, U.S. Patent No. 8547112, entitled " Introduced in monitoring system of high voltage equipments with capacitive insulation, such as condensing bushings, current transformers, potential transformers and similar "

An object of the present invention is to provide an apparatus and method for diagnosing a capacitor bushing of a transformer that can accurately diagnose a bushing insulation state of a transformer.

In order to solve the above problems, the present invention provides a transformer capacitor bushing diagnosing apparatus comprising a detector for detecting a state diagnostic value including at least one of a total current value, a resistive current value and a partial discharge amount generated in the capacitor bushing when a transformer is pressurized, ; And a rating calculation unit for calculating a rating for the condenser bushing of the transformer through comparison of the state diagnosis value and a preset reference value, wherein the reference value is set differently for each diagnosis target transformer, and 2 Two or more resistive current reference values having different values with respect to the resistive current value, and at least one of two or more partial discharge amount reference values having different values with respect to the partial discharge amount, .

The detecting unit may include a current detecting module that detects at least one of a total current value and a resistance current value generated in the capacitor bushing when the transformer is pressurized.

Further, the current detection module acquires the charging currents of the capacitor C1 group and the capacitor C2 group through the test tap included in the capacitor bushing, and based on the charging current obtained in the test tap of the capacitor C1 group and the capacitor C2 group, Can be detected.

In addition, the current detection module may be configured to remove noise from the charge current obtained in the test tap, remove the predetermined initial reference value, and sum the current values generated in predetermined frequency bands using the frequency band filter, The current value can be detected.

In addition, the predetermined frequency bands may include a frequency band of 170 to 190 MHz, 250 to 280 MHz, and 340 to 380 MHz.

Also, the predetermined initial reference value may be a capacitive current value, and the initial reference value may be a current value generated by a capacitance value measured through the insulation deterioration measuring device every predetermined period.

Further, the current detecting module can detect the total current value by acquiring the leakage current emitted from the test tap included in the capacitor bushing, and removing the conduction current and the radiation current from the leakage current.

The detecting unit may further include a partial discharge amount detecting module that detects a partial discharge amount generated in the capacitor bushing when the transformer is pressurized.

Further, the partial discharge amount detection module can detect the partial discharge amount based on the discharge amount of the test tab included in the capacitor C1 group and the capacitor C2 group.

Further, the transformer capacitor bushing diagnostic apparatus of the present invention may further comprise a display unit for displaying a status diagnosis value, a reference value, and a rating for a capacitor bushing of the transformer.

In addition, the transformer condenser bushing diagnostic apparatus of the present invention can be configured to be portable.

Further, the transformer capacitor bushing diagnosis apparatus of the present invention may further include a control unit for transmitting a warning signal to a Supervisory Control and Data Acquisition (SCADA) system when the rating of the capacitor bushing of the transformer is not a good grade.

According to another aspect of the present invention, there is provided a method of diagnosing a transformer capacitor bushing, comprising: detecting a state diagnostic value including at least one of a total current value, a resistive current value and a partial discharge amount generated in a capacitor bushing when a transformer is pressurized, ; And calculating a rating for the capacitor bushing of the transformer by comparing the state diagnostic value with a preset reference value by the rating calculator, wherein the reference value is set differently for each diagnosis target transformer, Two or more total current reference values having different values, two or more resistive current reference values having different values for the resistive current value, and at least one of two or more partial discharge amount reference values having different values for the partial discharge amount .

Further, the step of detecting the state diagnostic value may include detecting at least one of the total current value and the resistive current value generated in the capacitor bushing by the current detecting module when the transformer is pressurized.

The step of detecting at least one of the total current value and the resistive current value may include the steps of acquiring the charging current of the capacitor C1 group and the capacitor C2 group through the test tab included in the capacitor bushing, The resistive current value can be detected.

The step of detecting at least one of the total current value and the resistive current value may further include the steps of removing noise from the charging current obtained in the test tap, removing a preset initial reference value, The resistive current value can be detected by summing the current values generated in the bands.

In addition, the predetermined frequency bands may include a frequency band of 170 to 190 MHz, 250 to 280 MHz, and 340 to 380 MHz.

In addition, the step of detecting at least one of the total current value and the resistive current value may be performed by obtaining a leakage current emitted by the capacitor C1 group in the test tap included in the capacitor bushing, removing the conduction current and the radiation current from the leakage current, The current value can be detected.

The step of detecting the state diagnosis value may further include, by the partial discharge amount detection module, detecting a partial discharge amount generated in the capacitor bushing when the transformer is pressurized.

Further, the step of detecting the partial discharge amount may be based on the discharge amount of the test tap included in the capacitor C1 group and the capacitor C2 group.

Further, the method for diagnosing a transformer capacitor bushing of the present invention may further include displaying a status diagnosis value, a reference value, and a rating for a capacitor bushing of the transformer through a display unit.

In addition, the method of diagnosing a condenser bushing of the present invention may further include transmitting a warning signal to the SCADA system by the control unit when the rating of the capacitor bushing of the transformer is not a good grade.

According to the apparatus and method for diagnosing a transformer capacitor bushing of the present invention, it is possible to accurately diagnose the condition of the capacitor bushing, thereby maximizing the prevention of the failure.

In addition, according to the apparatus and method for diagnosing a transformer capacitor bushing of the present invention, it can be manufactured as a portable type and can be used as one product per establishment, which is economical.

In addition, according to the apparatus and method for diagnosing a transformer capacitor bushing of the present invention, the diagnosis state of a capacitor bushing is classified into classes and displayed on a touch screen display, thereby maximizing the convenience of a field surveyor.

Further, according to the apparatus and method for diagnosing a transformer capacitor bushing of the present invention, diagnosis is performed in the live state of the transformer, so that there is an effect that the operation of the substation is not stopped for diagnosis.

1 is a block diagram of a transformer capacitor bushing diagnostic apparatus according to an embodiment of the present invention.
2 is a conceptual diagram of a transformer capacitor bushing diagnostic apparatus according to an embodiment of the present invention.
3 is a table of reference values used through the transformer capacitor bushing diagnostic apparatus of the present invention.
4 is a flowchart illustrating a method of diagnosing a transformer capacitor bushing according to an exemplary embodiment of the present invention.

The present invention will now be described in detail with reference to the accompanying drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

Hereinafter, a transformer capacitor bushing diagnostic apparatus according to an embodiment of the present invention will be described.

1 is a block diagram of a transformer capacitor bushing diagnostic apparatus 100 according to an embodiment of the present invention. 2 is a conceptual diagram of a transformer capacitor bushing diagnostic apparatus 100 according to an embodiment of the present invention. The transformer capacitor bushing diagnosis apparatus 100 according to an embodiment of the present invention performs diagnosis of the capacitor bushing 10 on the basis of the current detected by the capacitor bushing 10 and the partial discharge amount during pressurization, The supervisory control and data acquisition system 20 notifies the supervisory control and data acquisition system 20 of the presence or absence of the observation grade. The transformer capacitor bushing diagnosis apparatus 100 according to an embodiment of the present invention includes a detection unit 110, a rating calculation unit 120, a control unit 130, a data analysis unit 140, a display unit 150, An analysis unit 160 and an input unit 170. Hereinafter, each configuration included in the transformer capacitor bushing diagnosis apparatus 100 according to an embodiment of the present invention will be described.

The detecting unit 110 detects a state diagnostic value generated in the capacitor bushing 10 when the transformer is pressurized. Here, the state diagnostic value is a value including at least one of a total current value, a resistive current value, and a partial discharge amount generated in the capacitor bushing 10 when pressurized. Here, the capacitor bushing 10 may be divided into two groups, that is, a capacitor C1 group and a capacitor C2 group. Here, the capacitor C1 group and the capacitor C2 group represent a group manufactured in the capacitor bushing 10 in order to ensure insulation between the main conductor and the ground and to mitigate impact current.

 Conventionally, in the diagnosis of the condenser bushing 10, the risk of failure is determined on the basis of the leakage current measurement value of the condenser C1 group. However, the reliability of the condenser bushing 10 can not be accurately diagnosed due to low reliability.

Accordingly, the detecting unit 110 according to the embodiment of the present invention detects the total current value through the capacitor C1 group, the resistance current value through the capacitor C1 group and the capacitor C2 group, and the resistance current value through the capacitor C1 group and the capacitor C2 group The partial discharge amount can be obtained. That is, in the lower part of the transformer capacitor bushing 10, insulating paper and aluminum plate capacitors are installed in two groups (group C1 and group C2 of capacitors) between the insulated enclosures (conductors to be energized) and the insulators . Here, 80 to 90% of the capacitor C1 group and 10 to 20% of the second capacitor C2 group are included. Also, a test tap is provided at the end of the capacitor C1 group, and the total current value can be detected using such a test tap as described above. Here, the test tab is normally grounded through the cover, and the test can be performed by separating the cover when measuring the current or the like for diagnosis of the present invention.

Also, when a voltage is applied to the capacitor bushing 10, a charging current is generated in the capacitor C1 group and the capacitor C2 group, and when an arc discharge occurs, a resistive current and a partial discharge are generated. Accordingly, the detection unit 110 according to an embodiment of the present invention can detect the resistive current value and the partial discharge amount through the group of the capacitor C1 and the group of the capacitor C2.

In the above description, the term total current represents the total current value generated inside the bushing when the transformer is pressurized, and the term resistive current represents the value of the risk of failure occurring inside the bushing when the transformer is pressurized.

The detection unit 110 according to an embodiment of the present invention may include a current detection module 111 and a partial discharge amount detection module 112. Here, the current detection module 111 functions to derive the total current value and the resistive current value based on the current flowing in the capacitor bushing 10 in a pressurized state. Further, the partial discharge amount detection module 112 functions to detect the partial discharge amount of the capacitor bushing 10 in the pressurized state. The current detection module 111 may include a CT (Current Transformer), and the partial discharge amount detection module 112 may include RF-CT.

The total current value can be detected through the current detection module 111. [ The detection procedure for the total current value is as follows. The current detection module 111 first obtains the leakage current that is emitted from the test tap included in the capacitor bushing 10. Here, the test tap is present at the end of the capacitor C1 group. Thereafter, the current detection module 111 performs filtering using the noise filter and the band-pass filter to conduct the conduction current (noise introduced from the ground side) and the radiation current at the leakage current, and detects the total current value based on the filtering .

The resistive current value can be detected through the current detection module 111. The detection process for the resistive current value is as follows.

First, the current detection module 111 acquires the charging current generated in the capacitor bushing 10 through the transformer bushing test tap. As described above, in the case of the resistive current and the partial discharge, when a voltage is applied to the capacitor bushing 10, a charging current is generated in the capacitor C1 group and the capacitor C2 group. Here, in the steady state, the charge current includes only the capacitive current (Ic current). However, when an arc discharge occurs due to the inflow of foreign substances (adhesive, sludge due to carbonization of insulating paper), water infiltration of insulating oil, faulty capacitor production, and deterioration of insulating paper, etc., the capacitor C1 group and the capacitor C2 group are subjected to a resistive current And a partial discharge occurs. In this case, the charging current includes not only the above-described capacitive current (Ic current) but also a resistive current. At this time, however, no inductive current (IL) is formed, but the inductive current (IL) occurs only in the case of failure due to dielectric breakdown.

Accordingly, the current detecting module 111 of the present invention detects the resistive current value using the charging current generated by the capacitor C1 group and the capacitor C2 group when the voltage is applied. For this, the current detection module 111 removes the initial reference value, that is, the capacitive current value Ic, from the charging current through the filtering process.

Thereafter, only the frequency generated in predetermined bands using the frequency band filter with respect to the charging current for which the initial reference value Ic is removed can be detected and detected as a resistive current based on the summed value in the detection results. The predetermined bands herein may include, for example, 170 to 190 MHz, 250 to 280 MHz, and 340 to 380 MHz bands, which may adversely affect the capacitor bushing 10 of the transformer. Here, the initial reference value (Ic) represents the value of the capacitor tested at the time of manufacture by the manufacturer for the transformer bushing installed in a nationwide business establishment. In addition, the initial reference value Ic may indicate the current value generated by the capacitor (capacitance value, unit pF) measured through the insulation deterioration measuring device every predetermined period.

The partial discharge amount can be detected through the partial discharge amount detection module 112. [ The detection procedure for the partial discharge amount is as follows. The partial discharge amount detection module 112 detects the partial discharge acquisition item using the RF-CT, and the discharge amount (electromagnetic wave) emitted from the transformer bushing test tap. Also, the partial discharge amount detection module 112 calculates the partial discharge amount based on the electromagnetic waves generated by exceeding the predetermined frequency band through the spectrum analysis. Here, in the case of an external electromagnetic wave, a frequency band of less than 160 MHz occurs, so that the frequency band for detecting the partial discharge amount can be made in a band of 160 MHz or more, for example.

In another embodiment of the present invention, the functions performed by the partial discharge amount detection module 112 are separated, that is, the partial discharge amount detection module 112 detects elements necessary for calculating the partial discharge amount, A method of detecting the partial discharge amount through the spectrum analyzer 160 shown in FIG.

The signal detected through the detection unit 110 is filtered through a noise filter and a band pass filter as shown in FIG. 2, that is, a harmonic, a conduction current, a radiation current are removed, and a filtered signal is transmitted. Also, in Figure 2, the portion shown below the filter is the protection circuit 180.

The rating calculator 120 calculates a state grade for the condenser bushing 10 by comparing the state diagnostic value detected through the detector 110 with a reference value. As described above, the state diagnostic value represents a value including at least one of a total current value, a resistive current value, and a partial discharge amount generated in the capacitor bushing. Similarly, the reference value may be set to two or more total current reference values having different values for the total current value, two or more resistive current reference values having different values for the resistive current value, and two And the partial discharge amount reference value. That is, the reference value may include a plurality of reference values per one attribute (for example, a total current value, a resistive current value, or a partial discharge amount). Accordingly, the class of the condenser bushing 10 can be divided into a plurality of classes.

Further, the reference value may be set differently for each transformer. At present, the value at the time of installation is used as a good judgment criterion when there is no insulation condition judgment value (good, observation, critical, bad grade) according to the manufacturer and the year of manufacture when applying diagnostic equipment for the transformer bushing only. When the insulation state of the bushing due to this is precaution, a defective grade, or if the insulation state is rapidly deteriorated, the state of the condenser bushing 10 can not be accurately determined. Accordingly, the transformer capacitor bushing diagnosis apparatus 100 according to an embodiment of the present invention sets the reference value different for each transformer, and performs the diagnosis on the capacitor bushing 10 based on the different reference value. An example of such a reference value is shown in Fig.

For example, assume that the total current measured at the transformer's bushings at A, B, and C substations is 14.70 mA and the resistive current is 2 mA. In this case, considering only the total current value, the transformer of the A substation is determined as the observation class, but the transformer of the B substation is the defective grade and the transformer of the C substation is determined as the good grade. In this example, the determination criteria of the A, B, and C substations, that is, the resistive current reference values are shown as being the same, but this is only an example, and they may be set different from each other as reference values for the total current.

In addition, in the present example, the state class for the capacitor bushing is described as being classified into four classes, that is, a good grade, an observation grade, a critical grade, and a bad grade, but this can also be set to a different number and a different name.

1 and 2, the display unit 150 may include at least one of a status diagnosis value detected through the detection unit 110, that is, a total current value, a resistive current value, and a partial discharge amount, And displays the state grade of the condenser bushing 10 calculated through the above-described operation. Here, the display unit 150 may include a touch screen panel. That is, considering the convenience of the operator using the transformer capacitor bushing diagnostic apparatus 100 of the present invention, the above-described information can be intuitively confirmed through the display unit 150, You can do more.

The controller 130 transmits a warning signal to the SCADA system 20 based on the rating of the capacitor bushing 10 calculated by the rating calculator 120. That is, the controller 130 functions to transmit a warning signal to the SCADA system 20 when the rating of the condenser bushing 10 is higher than the observation grade. To this end, the transformer capacitor bushing diagnostic apparatus 100 of the present invention may further include a communication unit, through which a warning signal may be transmitted in a wired or wireless communication manner.

The input section 170 may be used for operation of the transformer capacitor bushing diagnostic apparatus 100 of the present invention.

In addition, the transformer capacitor bushing diagnostic apparatus 100 according to an embodiment of the present invention can be manufactured as a portable type. As a result, the above-described diagnostic function can be performed with one product per business, which is economical.

4 is a flowchart illustrating a method of diagnosing a transformer capacitor bushing according to an exemplary embodiment of the present invention. The method for diagnosing a transformer capacitor bushing according to an embodiment of the present invention performs a diagnosis of a capacitor bushing based on a current detected by a capacitor bushing during pressurization and a partial discharge amount, SCADA system. Hereinafter, a method of diagnosing a transformer capacitor bushing according to an embodiment of the present invention will be described. Hereinafter, the elements overlapping with those referred to with reference to Figs. 1 and 2 will be omitted.

First, a detection step (S110) of detecting a state diagnostic value including at least one of a total current value, a resistive current value, and a partial discharge amount generated in the capacitor bushing when the transformer is pressurized is performed by the detection unit. As described above, the detection process performed in step S110 may be performed in the live state of the transformer, that is, in a state of being pressurized by the transformer. Thereby, the diagnosis process for the capacitor bushing mentioned below can be performed without stopping the operation of the substation. Also, as mentioned with reference to Figs. 1 and 2, the detection unit may be largely configured to include a current detection module and a partial discharge amount detection module.

Thereafter, the state calculating unit compares the state diagnostic value with a predetermined reference value (S120), and a step (S130) of calculating a class for the capacitor bushing of the transformer based on the comparison result in S120 is performed . Here, the reference value represents a value set for calculating the rating of the capacitor bushing, which can be set differently for each diagnosis target transformer. Also, the reference value may be set to two or more total current reference values having different values for the total current value, two or more resistive current reference values having different values for the resistive current value, and two reference current values having different values for the partial discharge amount Or more of the partial discharge amount reference value. Since an example of this is described in detail with reference to FIG. 3, a further explanation thereof will be omitted.

The classes calculated in step S130 can be largely divided into a good grade, an observation grade, a critical grade, and a bad grade, and the number and the name of each grade can be changed differently according to the setting of the operator.

Then, through the display unit, a step (S140) of displaying the status diagnosis value, the reference value, and the rating for the condenser bushing of the transformer detected and calculated in steps S110 and S130 is performed. Step S140 is performed for an operator operating the transformer capacitor bushing diagnostic apparatus of the present invention, and the display unit may be a touch screen type.

Thereafter, step S150 is performed to confirm whether the rating for the condenser bushing calculated in step S130 is equal to or higher than the observation grade. If it is determined in step S150 that the condenser bushing is above the observation grade, control is passed to step S160. Otherwise, the condenser bushing is in good condition, so control is transferred to the end block without further work on it.

Step S160 is a step (S160) of sending a warning signal to the SCADA system by the control unit. That is, the method for diagnosing a substation capacitor bushing according to the present invention aims at preventing the damage of a substation that may be caused by an abnormality of a capacitor bushing, and therefore, in step S160, Not only the operator is notified via the display unit but also an alarm signal is generated and transmitted to the SCADA system so that an accident caused by the condenser bushing can be prevented in advance.

As described above, an optimal embodiment has been disclosed in the drawings and specification. Although specific terms have been employed herein, they are used for purposes of illustration only and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: Transformer capacitor bushing diagnostic device
110: Detection unit 120:
130: control unit 140: data analysis
150: Display section 160: Spectrum analysis section
170:

Claims (20)

A transformer capacitor bushing diagnostic device comprising:
A detector for detecting a state diagnostic value including at least one of a total current value, a resistive current value, and a partial discharge amount generated in the capacitor bushing when the transformer is pressurized; And
And a rating calculation unit for calculating a rating for the capacitor bushing of the transformer through comparison between the state diagnostic value and a preset reference value,
The reference value is set differently for each diagnostic transformer, and two or more total current reference values having different values for the total current value, two or more resistive current reference values having different values for the resistive current value, At least one of two or more partial discharge amount reference values having different values from each other,
Wherein:
And a current detection module for detecting at least one of a total current value and a resistive current value generated in the capacitor bushing when the transformer is pressurized,
The current detection module includes:
Wherein a charging current of the capacitor C1 group and the capacitor C2 group is acquired through a test tap included in the capacitor bushing and the resistance current value is detected based on the charging current obtained in the test tap. Device. delete delete The method according to claim 1,
The current detection module includes:
And removing noise from the charge current obtained in the test tap and removing a predetermined initial reference value. 5. The method of claim 4,
The current detection module includes:
Wherein the resistive current value is detected by summing current values generated in predetermined frequency bands using a frequency band filter at a charge current at which the noise and a predetermined initial reference value are removed. 6. The method of claim 5,
Wherein the predetermined frequency bands include a frequency band of 170 to 190 MHz, 250 to 280 MHz, and 340 to 380 MHz. 6. The method of claim 5,
Wherein the predetermined initial reference value is a capacitive current value and the initial reference value is a current value generated by a capacitance value measured through an insulation deterioration measuring device every predetermined period. The method according to claim 1,
The current detection module includes:
Characterized in that the total current value is detected by obtaining a leakage current emitted by the capacitor C1 group in the test tap included in the capacitor bushing and removing the conduction current and the radiation current from the leakage current, Device. The method according to claim 1,
Wherein:
Further comprising a partial discharge amount detection module for detecting a partial discharge amount generated in the condenser bushing when the transformer is pressurized. The method according to claim 1,
Further comprising a display unit for displaying the status diagnosis value, the reference value, and the rating for the capacitor bushing of the transformer. The method according to claim 1,
Wherein said transformer capacitor bushing diagnostic device is portable. The method according to claim 1,
Further comprising a control for transmitting an alarm signal to a Supervisory Control and Data Acquisition (SCADA) system if the rating for the capacitor bushing of the transformer is not a good rating. A method for diagnosing a transformer capacitor bushing,
Detecting a state diagnostic value including at least one of a total current value, a resistive current value, and a partial discharge amount generated in the capacitor bushing when the transformer is pressurized; And
Calculating a rating for the condenser bushing of the transformer by comparing the state diagnostic value with a preset reference value by the rating calculator,
The reference value is set differently for each diagnosis target transformer, and two or more total current reference values having different values for the total current value, two or more resistive current reference values having different values for the resistive current value, At least one of two or more partial discharge amount reference values having different values from each other,
Wherein the step of detecting the state diagnostic value comprises:
Detecting at least one of a total current value and a resistive current value generated in the capacitor bushing by the current detection module when the transformer is pressurized,
Wherein the step of detecting at least one of the total current value and the resistive current value comprises:
Wherein a charging current of the capacitor C1 group and the capacitor C2 group is acquired through a test tap included in the capacitor bushing and the resistance current value is detected based on the charging current obtained in the test tap. Way. delete delete 14. The method of claim 13,
Wherein the step of detecting at least one of the total current value and the resistive current value comprises:
Removing noise from the charging current obtained in the test tap and removing a predetermined initial reference value. ≪ RTI ID = 0.0 > 11. < / RTI > 17. The method of claim 16,
Wherein the step of detecting at least one of the total current value and the resistive current value comprises:
Wherein the resistive current value is detected by summing current values generated in predetermined frequency bands in the charge current from which the noise and the reference value are removed using a frequency band filter. 18. The method of claim 17,
Wherein the predetermined frequency bands include a frequency band of 170 to 190 MHz, 250 to 280 MHz, and 340 to 380 MHz. 14. The method of claim 13,
Wherein the step of detecting at least one of the total current value and the resistive current value comprises:
Characterized in that the total current value is detected by obtaining a leakage current emitted by the capacitor C1 group in the test tap included in the capacitor bushing and removing the conduction current and the radiation current from the leakage current, Way. 14. The method of claim 13,
Wherein the step of detecting the state diagnostic value comprises:
Further comprising the step of detecting, by a partial discharge amount detection module, a partial discharge amount generated in the capacitor bushing when the transformer is pressurized.

Images