KR102624689B1 - Method and Device for Thermal Imaging Diagnosis of Overhead Gas Insulated Switchgears - Google Patents

Abstract

The method of diagnosing an aerial switch thermal image using the aerial switch thermal imaging diagnostic device (1) of the present invention is performed when the abnormal temperature of the aerial switch (100) is confirmed through the thermal image temperature image (20-1) of the thermal imager (20). The precision resistance meter 30 measures the resistance value at the connection point of the upper and lower contact pins 10A, 10B of the clamp 10 by applying electricity to the terminal 101 and the current generator 40, and the resistance measurement value is By checking the excess resistance value through the reference resistance value of the processing switch resistance-temperature map and resolving the electrical contact defect of the terminal 101, the reliability of thermal imaging diagnosis and work convenience are provided, especially the clamp 10 A structure that increases the contact point with the terminal side wires (102B, 103B) by the upper/lower contact pins (10A, 10B) makes resistance measurement easy and accurate, but does not require removal through thermal imaging diagnosis. By accurately understanding this, it has the characteristic of reducing costs by preventing the indiscriminate removal and replacement of the processing switch 100.

Description

{Method and Device for Thermal Imaging Diagnosis of Overhead Gas Insulated Switchgears}

The present invention relates to thermal image diagnosis of an overhead switch, and in particular, a thermal image diagnosis method of an overhead switch that prevents indiscriminate demolition based on temperature abnormalities by using a reference resistance value for the terminal side resistance value. It's about devices.

In general, overhead gas insulated switchgears are devices that open or connect distribution lines. They are circuit protection devices that detect the current or voltage generated on the high-voltage lines of high-voltage circuits installed on electric poles, etc. and change the open and closed status of the high-voltage circuit. It is a device.

There are many cases of extraction of such overhead switches for power distribution through thermal imaging diagnosis of Eco switches, reclosers (Automatic Circuit Reclosers), and EFI (Epoxy insulated Fault Interrupters). In this case, the Eco switch is a load switch for installing epoxy-insulated wiring lines, the recloser is used to block temporary failures in distribution lines or to separate fault sections, and the EFI uses epoxy rather than SF6 gas. This is a circuit breaker that uses an insulating medium and has a blocking time of 3 cycles or less.

For example, the case of thermal imaging diagnostic extraction of the switchgear is caused by poor clamping and surface corrosion such as the clamp fastening part, bushing part, and opening and closing part.

Specifically, the cause of the clamp connection part is due to poor clamp connection in the clamp connection state, and poor clamp connection causes corrosion/arc generation and poor connection of U-bolts. The cause of the bushing part is due to the opening of the CT (Current Transformer), which introduces high voltage during manual operation of the automatic switch. The cause of the opening/closing part is a defect in the VI (Vacuum Interrupter) connection due to an increase in contact resistance due to poor connection between the mover and the internal conductor.

Therefore, the overhead switch can maintain performance that ensures the safety of the distribution line by replacing it with a new product through thermal imaging diagnosis of the switch.

Domestic registered patent KR 10-0764066 B

However, existing thermal imaging diagnostic methods have limitations in that they cannot accurately determine the phenomenon or cause of poor clamping and surface corrosion that require removal of the switch.

The cause of this is the absence of a standard resistance value that determines the poor connection of the overhead switch as a result of heat generation due to Joule heat, and the structural shortcomings of the fixture-wire fixation of the clamp, which makes it difficult to install (i.e., insert) the resistance measuring clip on the overhead switch. It is being attributed.

As a result, poor clamping and surface corrosion account for about 90% of the causes of demolition of overhead switches, so indiscriminate demolition of switches without accurate thermal imaging diagnosis is causing great losses.

Accordingly, the present invention, taking the above into account, improves the reliability of thermal imaging diagnosis by applying a reference resistance value that can diagnose the cause of clamping failure to the resistance measurement value, thereby providing convenience in diagnostic work, and in particular, multiple clamps Thermal image diagnosis of overhead switches enables easy resistance measurement and measurement accuracy by increasing the contact points of wires on the terminal side by contact pins, while reducing costs by preventing indiscriminate removal and replacement of overhead switches by accurately identifying terminal fastening defects that do not require removal. The purpose is to provide methods and devices.

The thermal image diagnosis method for an aerial switch of the present invention to achieve the above object is to verify the thermal image temperature image in which the abnormal temperature of the aerial switch is confirmed with an aerial switch resistance-temperature map, and through the verification, the terminal side of the aerial switch is It is characterized by including a thermal imaging diagnostic verification procedure to confirm contact defects.

In a preferred embodiment, the thermal image temperature image represents the temperature distribution of the overhead switch in different colors, and the overhead switch resistance-temperature map represents a reference resistance value for the excess resistance value of the terminal.

In a preferred embodiment, the steps of the thermal image diagnosis verification procedure include installing a thermal imager around the processing switch, confirming the abnormal temperature in the thermal image temperature image secured by the thermal imager, and A thermal image analysis step in which the need for precise diagnosis of the processing switch is confirmed based on temperature. A clamp is attached to the terminal, a precision resistance meter and a current generator are connected to the clamp, the resistance value of the terminal is measured by the precision resistance meter with a current flow of the current generator, and the processing switch resistance-temperature map A reference resistance comparison step in which the verification is performed by confirming the resistance measurement value as an excess resistance value, and a step in which contact defects on the terminal side are removed by checking the connection state of the terminal.

In a preferred embodiment, the thermal imager captures the processing switch and generates the thermal image temperature image.

In a preferred embodiment, the abnormal temperature is confirmed by the thermal temperature of the processing switch and the ambient temperature of the processing switch shown in the thermal image temperature image, and the abnormal temperature is an ambient temperature greater than the ambient temperature threshold of 10 to 20 ° C. Confirmed by car.

In a preferred embodiment, the abnormal temperature is confirmed as the temperature for each phase of the processing switch shown in the thermal image temperature image, and the abnormal temperature is confirmed as a temperature difference for each phase that is greater than the temperature threshold for each phase of 5 to 10 ° C.

In a preferred embodiment, the processing switch is confirmed to be in a normal state without confirmation of the abnormal temperature.

In a preferred embodiment, the clamp is provided with a plurality of upper contact pins and a lower contact pin, and each of the upper contact pins and the lower contact pins is engaged with the upper wire on the load side terminal side or the lower wire on the power side terminal side of the terminal. The current from the current generator flows.

In a preferred embodiment, the excess resistance value is identified as a clamp-to-wire resistance difference greater than the excess resistance threshold of 1 mΩ.

In a preferred embodiment, when the excess resistance value is not confirmed by the resistance measurement value, the overhead switch is determined to be defective.

In order to achieve the above object, the thermal imaging diagnostic device for an aerial switch of the present invention includes a clamp provided with a plurality of upper contact pins and lower contact pins that are connected to the terminal of the aerial switch and form a connection point with the wire, and heat generation of the aerial switch. It is characterized in that it includes a thermal imager that generates a thermal image of temperature, a precision resistance meter that measures the resistance value of the terminal with a current flowing in the clamp, and a current generator that conducts electricity with the clamp.

In a preferred embodiment, the clamp is provided with a plurality of upper contact pins and a plurality of lower contact pins at a predetermined interval.

The thermal imaging diagnosis method and device for a processing switch of the present invention implements the following operations and effects.

First, the accuracy of thermal imaging diagnosis for overhead switches is increased by comparing resistance values, making it easier to determine whether or not to remove the overhead switches at the site. Second, by improving the accuracy of thermal imaging diagnosis for clamping defects and surface corrosion, which account for approximately 90% of the removal of overhead switches, it is possible to reduce indiscriminate on-site removal of overhead switches that require replacement costs. Third, by establishing a resistance-temperature correlation diagram through testing of clamp connection resistance and heat generation, it is possible to easily diagnose the cause of clamping defects in overhead switches using reference resistance values in the field. Fourth, the structure of the clamp that increases the resistance contact point of the stranded wire can solve the difficulty of biting that occurred during work with the existing clamp metal fitting-wire fixing structure. Fifth, due to the increased accuracy of resistance measurement values due to the structure of increasing contact points of the clamp, thermal imaging diagnosis can be divided into clamp construction problems that require fastening work and internal problems of the switch that require replacement work, thereby preventing indiscriminate removal and replacement of machined switchgear. Cost savings are also possible.

Figure 1 is a flow chart of a thermal image diagnosis method for an aerial switch according to the present invention, Figure 2 is a configuration diagram of a thermal image diagnosis device for an aerial switch according to the present invention, and Figure 3 is a diagram showing the resistance of an aerial switch according to the present invention - applied to the temperature map. Clamp - Aerial switch resistance using a wire connection point - an example of a temperature correlation diagram, Figure 4 is an example of a thermal image temperature image of an image capture device for thermal image diagnosis of an aerial switch according to the present invention, and Figure 5 is a clamp according to the present invention. is connected to the terminal of the processing switch for resistance measurement.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached illustration drawings. These embodiments are examples and may be implemented in various different forms by those skilled in the art to which the present invention pertains, so they are described herein. It is not limited to the embodiment.

Referring to FIG. 1, the aerial switch thermal image diagnosis method uses the thermal image temperature image 20-1 (see FIG. 4), in which the abnormal temperature of the aerial switch 100 (see FIG. 2) is confirmed, as an aerial switch resistance-temperature map. (see FIG. 3), and is implemented as a thermal imaging diagnostic verification procedure (S10 to S50) in which a contact defect on the terminal 101 of the processing switch 100 is confirmed through the verification.

To this end, the steps of the thermal imaging diagnosis verification procedure (S10 ~ S50) are the switch excess temperature diagnosis procedure ( S10~S20), followed by the switch excess resistance diagnosis procedure (S30~S40), which determines the removal of the overhead switch using the terminal resistance data obtained from the switch resistance measurements of the clamp.

As a result, the process switch removal work can be divided into simple maintenance diagnosis (S50), normal diagnosis (S100), and demolition diagnosis (S200).

Therefore, the thermal imaging diagnosis method of the overhead switch applies a standard resistance value determination procedure to the resistance value of the clamp area, thereby reducing the cost due to the existing thermal imaging diagnosis method in which the overhead switch was dismantled only due to temperature abnormalities confirmed by the thermal imaging image of the switch. It is possible to implement features that result in large losses.

Meanwhile, referring to FIG. 2, the processing switch thermal imaging diagnostic device 1 is composed of a clamp 10, a thermal imager 20, a precision resistance meter 30, and a current generator 40.

For example, the clamp 10 is a tool that is clamped to the terminal 101 of the processing switch 100 to measure the resistance value of the terminal 101 in the precision resistance meter 30, and uses a seasaw movement centered on the hinge axis. It consists of two clamp hook structures (i.e., scissors structure) (see FIG. 5) that are clamped to the terminal 101 through motion).

For example, the thermal imager 20 captures an image of the processing switch 100, and converts the captured image into a thermal image representing the temperature distribution (i.e., temperature difference) of the processing switch 100 and the surrounding space in color. It is provided as a temperature image (20-1) (see FIG. 4).

For example, the precision resistance meter 30 and the current generator 40 measure the resistance value generated at the terminal 101 of the processing switch 100, and for this purpose, the current generator 40 is connected to the terminal 101 and A current of about 100A flows toward the upper and lower contact pins (10A, 10B) of the bitten clamp (10), and the precision resistance meter (30) measures precision resistance with a micro-ohm meter, through which the resistance of the terminal (101) is measured. By detecting or measuring the value and analyzing it in connection with the temperature of the thermal imager 20, it is possible to check whether the fastening condition of the clamp fitting to the terminal 101 of the processing switch 100 is defective.

Therefore, the thermal imaging diagnosis device (1) for the processing switch (100) is a repetitive experiment using a combination of the clamp (10), the thermal imager (20), the precision resistance meter (30), and the current generator (40). A resistance-temperature map for terminal 101 can be constructed.

In particular, Figure 3 is an example of construction of an aerial switch resistance-temperature map using the aerial switch thermal imaging diagnostic device 1, and the aerial switch resistance-temperature map is a precision resistance meter ( By applying the temperature value to the resistance measurement value detected in 30), it can be seen that the resistance value of the terminal 101 is constructed as a graph related to the temperature value of the thermal imager 20. In this case, the content of the test is to measure the resistance and temperature difference (see table) as the contact resistance between the clamp (10) of the overhead switch (100) and the terminal wires (102B, 103B) changes while applying a current of about 100A, and measure the correlation diagram (graph). (reference).

Therefore, the overhead switch resistance-temperature map is the difference in ambient temperature of the overhead switch 100 obtained from the switch exceedance temperature diagnosis procedure (S10 to S20) and the terminal of the overhead switch 100 obtained from the switch exceedance resistance diagnosis procedure (S30 to S40). Temperature matching contributes to determining whether poor clamping and surface corrosion, which are the main causes of demolition of processing switches, are poor contact of the terminal (101).

Meanwhile, the overhead switch 100 is a circuit protection device that changes the open and closed state of the high-voltage circuit. The terminal 101 to which the clamp 10 is engaged is the load terminal 102A and the lower wire to which the upper wire 102B is connected, as shown in Figure 5. It is divided into a power terminal (103A) to which (103B) is connected. In this case, each of the load side terminal 102A and the power side terminal 103A is fixed by fastening a single bottom clamp (or clamp metal fitting (not shown)).

Hereinafter, the thermal image diagnosis method of the overhead switch of FIG. 1 will be described in detail with reference to FIGS. 2 to 5.

First, the thermal image diagnosis procedure for the overhead switch 100 is performed in the switch excessive temperature diagnosis procedure (S10 to S20), including the setting step of the thermal imaging diagnosis device of the overhead switch 100 at S10 and the thermal image analysis step at S20.

Referring to FIG. 2, the processing switch thermal imaging diagnostic device setting (S10) is arranged and installed with a thermal imager 20, a precision resistance meter 30, and a current generator 40 around the processing switch 100. This is then performed by connecting the power and signal lines. In this case, the clamp 10 can be set at the same time, but is preferably installed when performing the switch excessive resistance diagnosis procedure (S30 to S40).

And the step of analyzing the thermal image (S20) is performed as a step of generating a thermal image temperature image in S21, a step of confirming the diagnostic temperature in S22, and a step of confirming that the first or more diagnostic conditions are met in S23.

Figure 4 is a thermal image temperature image 20-1 of the thermal imager 20, and the thermal image temperature image 20-1 shows the temperature distribution of the processing switch 100 and the surrounding space and the temperature difference. is displayed as a color change depending on temperature.

Therefore, the thermal image temperature image generation (S21) can acquire the thermal image temperature image (20-1). The diagnostic temperature check (S22) is based on the temperature difference between the processing switch 100 and the surrounding space or the terminal of the processing switch 100 ( This is confirmed by the temperature difference between 101) and the surrounding space.

For example, confirmation that the primary abnormality diagnosis condition is satisfied (S23) is performed using the following excess temperature determination formula.

Excess temperature judgment formula

Case 1: A > a ?

Case 2: B > b ?

Here, A is the ambient temperature difference between the heating temperature of the processing switch 100 and its surrounding environment, a is the ambient temperature threshold set at 10 to 20 ℃, and B is the terminal of the processing switch 100. The temperature difference b for each phase on the (101) side is the temperature threshold for each phase set at 5 to 10°C.

As a result, when the ambient temperature difference (A) is less than 10 to 20 ℃ (a) or the temperature difference (B) for each phase is less than 5 to 10 ℃ (b), the processing switch 100 is in a normal state, so S100 The processing switch switches to the normal diagnosis stage.

Therefore, the transition to the normal diagnosis of the overhead switch (S100) stops the procedure of the thermal imaging diagnosis method of the overhead switch.

On the other hand, when the ambient temperature difference (A) is greater than 10 to 20 ℃ (a) or the temperature difference (B) for each phase is greater than 5 to 10 ℃ (b), the processing switch 100 is in an abnormal state in terms of temperature. Therefore, the excess resistance diagnosis procedure (S30~S40) is performed.

In this way, the switch excessive temperature diagnosis procedure (S10 ~ S20) is performed by the current switch 100 obtained by the thermal image temperature image 20-1 of the thermal imager 20 of the switch thermal imaging diagnosis device 1. Since the measured temperature has a certain temperature difference from the surrounding temperature, the need for precise diagnosis before demolition of the processing switch 100 can be confirmed.

Continuing, the procedure for diagnosing the resistance value for the overhead switch 100 is performed in the excess resistance diagnosis procedure (S30 to S40), including the clamp fastening step of S30 and the reference resistance comparison step of S40.

Referring to FIG. 5, the clamp 10 divides the two clamp hooks into an upper clamp hook and a lower clamp hook, has a plurality of upper contact pins 10A on the upper clamp hook, and has a lower contact pin on the lower clamp hook. A plurality of pins 10B are provided. In this case, each of the upper and lower contact pins 10A and 10B is shaped like a bar pin with a small cross-sectional size, and penetrates the upper and lower clamp hooks at a predetermined interval and protrudes into the space of the clamp hook.

Therefore, the clamp 10 is clamped to the upper wire 102B of the load terminal 102A or the lower wire 103B of the power terminal 103A among the terminals 101 of the processing switch 100 using two clamp hooks. When this happens, the plurality of bar-shaped pins constituting the upper and lower contact pins 10A and 10B protruding from the space of the clamp hook effectively form electrical contact with the terminal 101, respectively.

From this, the clamp fastening (S30) creates a state in which sufficient electrical contact points between the upper and lower contact pins (10A, 10B) of the clamp (10) and the wires (102B, 103B) are secured, and the precision resistance meter (30) And the current generator 40 is connected to the clamp 10 (i.e., the upper and lower contact pins 10A and 10B).

Specifically, the reference resistance comparison (S40) is performed in the terminal resistance data generation step of S41, the diagnostic resistance value confirmation step of S42, and the secondary abnormality diagnosis condition satisfaction step of S43.

2 and 4, the terminal resistance data generation (S41) is performed by connecting the precision resistance meter 30 and the current generator 40 to the clamp 10 (i.e., the upper and lower contact pins 10A and 10B). After connection, the precision resistance meter 30 measures the resistance value of the terminal 101 (i.e., the wires 102B and 103B) through the current supplied to the current generator 40. In this case, the work of fastening the clamp (S30) is performed by fastening the clamp 10 to the power side terminal 103A and measuring the resistance value after completing the fastening of the clamp 10 to the load side terminal 102A and measuring the resistance value. Or the opposite can be done.

For example, the diagnostic resistance value check (S42) is the terminal resistance value measured at the load terminal 102A or the power terminal 103A, which is the terminal 101 of the overhead switch, and the terminal resistance value is the switch clamp-wire of FIG. 3. The connection point resistance-temperature results can be illustrated in a table.

In particular, satisfying the secondary abnormality diagnosis condition (S43) is performed using the following excess resistance determination formula.

Excess resistance judgment formula: D >d ?

Here, D is the resistance difference between the clamp and wire, and d is the excess resistance threshold set to 1 mΩ.

As a result, when the resistance difference (D) between the clamp and the wire is less than 1 mΩ, the overhead switch 100 is in a normal state, so the process switches to the step of dismantling the overhead switch of S200 and detailed inspection of device defects.

Therefore, the transition to the removal of the overhead switch and detailed inspection of device defects (S200) involves stopping the procedure of the thermal imaging diagnosis method for the overhead switch and dismantling the overhead switch 100.

On the other hand, if the resistance difference (D) between the clamp and the wire is greater than 1 mΩ, the terminal 101 of the overhead switch 100 is in poor contact in terms of resistance, so the terminal part of the overhead switch 100 of S50 is fastened.

Finally, the terminal connection step of the overhead switch of S50 is the load terminal (102A) and the upper wire (102B) and/or the power terminal (103A) and the lower wire among the terminals (101) of the overhead switch (100) that show a current resistance value or higher. Poor contact between the wires (102B, 103B) occurring at the terminal (101) of the overhead switch (100) by re-tightening the terminal clamp (or clamp bracket (not shown)) connecting (103B) or replacing it with a new product. The condition is resolved.

In this way, the excess resistance diagnosis procedure (S30 ~ S40) uses the current measured resistance value of the overhead switch 100 obtained by the precision resistance meter 30 of the thermal imaging diagnostic device 1 to determine the resistance of the terminal 10. By identifying contact defects, the processing switch 100 that needs to be removed can be clearly identified.

As described above, the processing switch thermal image diagnosis method using the processing switch thermal imaging diagnosis device 1 according to this embodiment is the processing switch 100 using the thermal image temperature image 20-1 of the thermal imager 20. In a state in which an abnormal temperature of By measuring the resistance value and confirming it as an excess resistance value through the standard resistance value of the processing switch resistance-temperature map, the electrical contact defect of the terminal 101 is resolved, thereby improving the reliability of thermal imaging diagnosis and providing convenience of work. In particular, the structure of increasing the contact point with the terminal side wires (102B, 103B) by the upper and lower contact pins (10A, 10B) of the clamp (10) makes it easy and accurate to measure resistance, and can be removed through thermal imaging diagnosis. By accurately identifying non-required terminal fastening defects, cost savings are achieved by preventing the indiscriminate removal and replacement of the processed switch 100.

1: Process switch thermal imaging diagnostic device
10: Clamp 10A, 10B: Upper/lower contact pins
20: Thermal imager 20-1: Thermal image temperature image
30: Precision resistance meter 40: Current generator
100: Process switch
101: terminal 102A: load side terminal
102B: upper wire 103A: power supply terminal
103B: lower wire

Claims (18)

The thermal image temperature image, in which abnormal temperatures of the aerial switch were confirmed, was verified using the aerial switch resistance-temperature map,
The verification includes a thermal imaging diagnostic verification procedure in which defective contact at the terminal of the processing switch is confirmed,
The steps of the thermal imaging diagnostic verification procedure include installing a thermal imaging camera around the processing switch, confirming the abnormal temperature in the thermal image temperature image secured by the thermal imaging camera, and Thermal image analysis stage where the need for precise diagnosis is confirmed. A clamp is attached to the terminal, a precision resistance meter and a current generator are connected to the clamp, the resistance value of the terminal is measured by the precision resistance meter through a current flow of the current generator, and the processing switch resistance-temperature map A reference resistance comparison step in which the verification is performed by confirming the resistance measurement value as an excess resistance value, and a step in which contact defects on the terminal side are removed by checking the connection state of the terminal;
The clamp has a plurality of upper contact pins and a lower contact pin, and each of the upper contact pins and the lower contact pins is connected to the upper wire on the load side terminal side of the terminal or the lower wire on the power side terminal side of the terminal to generate a current of the current generator. A thermal imaging diagnosis method for a processing switch, characterized in that it flows.
The method of claim 1, wherein the thermal image temperature image represents the temperature distribution of the aerial switch in different colors.
The method of claim 1, wherein the aerial switch resistance-temperature map represents a reference resistance value for an excess resistance value of the terminal.
delete The method of claim 1, wherein the thermal imager captures the aerial switch and generates the thermal image temperature image.
The method according to claim 1, wherein the abnormal temperature is confirmed by the heating temperature of the aerial switch and the ambient temperature of the aerial switch shown in the thermal image temperature image.
The method of claim 6, wherein the abnormal temperature is confirmed as an ambient temperature difference greater than an ambient temperature threshold.
The method of claim 7, wherein the ambient temperature threshold is 10 to 20°C.
The method according to claim 1, wherein the abnormal temperature is confirmed by the temperature of each phase of the aerial switch shown in the thermal image temperature image.
The method of claim 9, wherein the abnormal temperature is confirmed by a temperature difference (B) for each phase greater than a temperature threshold for each phase.
The method of claim 10, wherein the temperature threshold for each phase is 5 to 10°C.
The method of claim 1, wherein the overhead switch is confirmed to be in a normal state when the temperature is not at the abnormal temperature.
delete The method of claim 1, wherein the excess resistance value is confirmed as a resistance difference between the clamp and the wire that is greater than an excess resistance threshold.
The method of claim 14, wherein the excess resistance threshold is 1 mΩ.
The method according to claim 1, wherein when the resistance measurement value is greater than 1 mΩ, the overhead switch is determined to be defective.
A clamp equipped with a plurality of upper and lower contact pins that connect to the terminal of the processing switch and form a connection point with the wire,
A thermal imaging device that generates a thermal image temperature image of the heating temperature of the processing switch,
A precision resistance meter that measures the resistance value of the terminal with the current flowing in the clamp, and
A current generator electrically connected to the clamp
A thermal imaging diagnostic device for a processing switch, characterized in that it includes.
The thermal imaging diagnostic device for a processing switch according to claim 17, wherein the clamp includes a plurality of the upper contact pins and the lower contact pins at a predetermined interval.

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