KR-102961183-B1 - CABLE TERMINATION JUNCTION BOX OZONE GAS DETECTION METHOD

KR102961183B1KR 102961183 B1KR102961183 B1KR 102961183B1KR-102961183-B1

Abstract

The ozone gas detection method for monitoring the ozone concentration inside the cable terminal junction box of the present invention may include: a step of performing a general measurement as a first event monitoring and entering a sleep mode when the ozone concentration exceeds a reference level in an initial monitoring mode; a step of performing a detailed measurement as a comparison event monitoring and entering a sleep mode when the ozone concentration exceeds a reference level in a sleep mode after performing the general measurement; a step of entering an initial monitoring mode when the ozone concentration does not exceed a reference level in a sleep mode after performing the detailed measurement; and a step of increasing the number of ozone continuous detections when the measured ozone concentration exceeds a range of 0.

Inventors

임재섭
여근택
김봉덕
조계현

Assignees

한국전력공사

Dates

Publication Date: 20260507
Application Date: 20250410

Claims (4)

As a method for detecting ozone gas in a cable terminal box for monitoring ozone concentration inside the cable terminal box, In the initial monitoring mode, if the ozone concentration exceeds a reference level, a step of performing a general measurement as initial event monitoring and entering a sleep mode; In the sleep mode after performing the above general measurement, if the ozone concentration exceeds a reference level, a step of performing a detailed measurement as a comparative event monitoring and entering the sleep mode; and In the sleep mode after performing the detailed measurement above, if the ozone concentration does not exceed the reference level, a step of entering the initial monitoring mode; If the measured ozone concentration exceeds the range of 0, the step of increasing the number of continuous ozone detections Includes, The step of performing the above general measurements and entering sleep mode is, A step of initiating a run mode and measuring the ozone concentration of the terminal connection box; If the measured ozone concentration falls within the range of 0, a step of initializing the parameters for the detailed measurement; If the measured ozone concentration exceeds the reference level, the step of storing the measured ozone concentration and related information; and Step of entering the sleep mode when the measured ozone concentration does not exceed the reference level, or when the ozone concentration and related information are stored. A method for detecting ozone gas in a cable termination junction box including
In paragraph 1, The step of storing the measured ozone concentration and related information is, A step of reducing the sleep time to maintain the above sleep mode; Step of increasing the number of continuous ozone detections; A step of reflecting the measured ozone concentration in the previous and maximum measured values for the ozone concentration; and Step of storing reduced, increased, or reflected parameters A method for detecting ozone gas in a cable termination junction box including
In paragraph 1, The step of performing the above detailed measurements and entering sleep mode is, A step of initiating a run mode and measuring the ozone concentration of the terminal connection box; If the measured ozone concentration is greater than the ozone concentration value measured and stored immediately prior, a step of reducing the sleep time to maintain the sleep mode; If the measured ozone concentration is smaller than the ozone concentration value measured and stored immediately prior, a step of increasing the sleep time to maintain the sleep mode; A step of storing the measured ozone concentration and related information; and When the above ozone concentration and related information are stored, the step of entering the above sleep mode A method for detecting ozone gas in a cable termination junction box including
In paragraph 3, The step of storing the measured ozone concentration and related information is, Step of increasing the number of continuous ozone detections; A step of reflecting the measured ozone concentration in the previous and maximum measured values for the ozone concentration; and Step of storing reduced, increased, or reflected parameters A method for detecting ozone gas in a cable termination junction box including

Description

Cable Termination Junction Box Ozone Gas Detection Method The present invention relates to an IoT-based ozone gas detection method and apparatus for an ultra-high voltage underground cable terminal junction box, and more specifically, to a terminal junction box ozone gas detection method in which the terminal junction box is directly connected to a drain valve installed in the protective copper pipe of the cable terminal junction box. Ultra-high voltage power cables, which are one of the major facilities in domestic and international ultra-high voltage substations, are used to smoothly supply power to GIS and transformers. The structure of ultra-high voltage power cables can be divided into cables and joint boxes, and joint boxes are classified into intermediate joint boxes and terminal joint boxes depending on their installation location. When partial discharge occurs due to insulation degradation in terminal junction boxes, physical phenomena such as heat, arcs, electromagnetic waves, and currents are generated by the minute, instantaneous high-energy source of the partial discharge signal. Therefore, it is important to conduct fault prevention activities by measuring these physical phenomena to prevent failures and accidents caused by insulation degradation in advance. Accidents involving ultra-high voltage power cables occur in junction boxes, and in particular, accidents occurring in terminal junction boxes can spread to transformers and GIS. Therefore, to prevent failures, regular diagnostics (partial discharge measurement, chemical analysis) and a continuous partial discharge monitoring system are operated for terminal junction boxes. Regular diagnostic cycles are measured every 1 to 3 years for partial discharge measurement and every 3 years for chemical analysis, so it is practically difficult to determine signs of failure in a timely manner. To replace this, failure prevention activities are performed through a continuous partial discharge monitoring system; however, since this is an electrical degradation diagnosis method, while it is effective in detecting degradation, it has the disadvantage of low reliability due to exposure to ambient electrical environmental noise. In order to diversify the aforementioned failure prevention activities, a diagnostic method using chemical substances generated by deterioration, particularly ozone, can be considered. A minute arc phenomenon caused by partial discharge in a terminal junction box comes into contact with air, decomposing oxygen molecules ( O₂ ) in the air into monatomic oxygen (O), and this monatomic oxygen combines with oxygen molecules in the air to become ozone ( O₃ ) gas. However, ozone gas is an unstable gas with a half-life that decomposes back into oxygen after a short period of time, making it difficult to detect the deterioration of the terminal junction box in a timely manner during actual operation. Meanwhile, current Wireless Sensor Network (WSN) technology has secured the technical foundation to realize a complete Internet of Things (IoT) by utilizing big data technology to collect and manage vast amounts of data acquired from sensors, as well as artificial intelligence learning to effectively analyze this data. For such wireless network technologies to be commercialized, installation must be simple, and for this to be possible, the selection of power supply and communication methods is crucial. However, it is currently very difficult to supply commercial power to terminal junction boxes installed and operating in substations and transmission towers, and a separate power source, such as batteries, is absolutely necessary. This has resulted in limitations on the frequency of ozone gas concentration detection, which consumes a significant amount of power. FIG. 1a is a cutaway perspective view illustrating the structure of a power cable termination junction box. Fig. 1b is a photograph of a power cable termination box in a faulty state. Figure 2 is a graph showing the partial discharge occurrence characteristics in a power cable termination junction box. Figure 3 is a graph showing the ozone gas retention time curve inside the terminal junction box. FIG. 4 is a block diagram illustrating the configuration of an ozone detection device that can be installed in a manner directly connected to a drain valve installed in a protective copper pipe of a terminal connection box. Figure 5 is a graph illustrating an ozone concentration detection method in a general wireless sensor network. FIG. 6 is a graph showing the concept of a method for measuring the concentration of ozone gas in a terminal connection box according to the concept of the present invention. FIG. 7 is a graph illustrating the concept of a data analysis method applied after measuring the concentration of ozone gas in a terminal connection box according to the concept of the present invention. FIG. 8 is a flowchart illustrating an embodiment of a method for detecting ozone gas in a