JPH0547075B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention intensively monitors the luminescence state of contaminated corona generated from the insulators of power transmission towers that are distributed over a wide area, and The present invention relates to a method for monitoring corona contaminated power transmission lines, which can issue cleaning commands.

(Prior Art) It is widely known that as the insulators that support power transmission lines become more contaminated, their insulation performance deteriorates and fouling corona is generated. For this reason, either the locations of power transmission line towers are divided into districts based on the rate of progress of contamination, and cleaning is carried out according to a fixed schedule regardless of the actual degree of contamination. Maintenance is carried out to prevent contamination from exceeding a certain limit, such as by measuring the level and cleaning when it exceeds a certain level, or by cleaning after receiving a notification from nearby residents that there is a corona disorder. I'm going. However, none of the above-mentioned conventional methods can directly determine the contamination status of actual insulators, and it is difficult to determine the effective cleaning period for steel towers that are distributed over a wide area, making maintenance work more efficient. However, problems remained in terms of rapid response.

(Problems to be Solved by the Invention) The present invention solves the conventional problems as described above, makes it possible to directly grasp the state of pollution and corona occurrence in real insulators, and improves the effectiveness of insulators on steel towers, which are distributed over a wide range of areas. This was completed with the aim of providing a method for monitoring contaminated power transmission lines and corona that would issue cleaning instructions at appropriate times.

(Means for Solving the Problems) The present invention includes a current sensor on the tower side of a power transmission line that detects leakage current flowing on the insulator surface, and a radio wave sensor that detects radio noise radio waves generated from the insulator during corona discharge. The measured values are transmitted to the control center via an overhead ground fiber optic cable, and the control center uses an arithmetic processing unit to count the number of times the radio noise radio wave intensity exceeds a set value and calculate the frequency of corona occurrence. In addition, the corona luminous intensity is calculated while correcting the correlation equation between the leakage current value and the corona luminous intensity based on the frequency of corona occurrence, and a cleaning command is issued when the corona luminous intensity exceeds a set level. It is.

As described above, the present invention converts the measured value of the leakage current flowing on the surface of the insulator and the measured value of the radio noise radio waves generated due to the generation of contamination corona into optical signals, and then transmits them to the control center via an optical fiber cable. However, a processing unit in the control center calculates the corona luminous intensity indicating the corona luminous state, and will be explained in more detail below with reference to examples.

(Example) In FIG. 1, 1 is a transmission line tower, 2 is an insulator that is attached to the tower arm and insulates and supports the power transmission line 3, and 4 is connected to each tower 1 and an overhead ground line optical fiber cable 5. It is a connected control center. A current sensor 6 for detecting leakage current flowing on the surface of the insulator and a radio wave sensor 7 for detecting radio noise radio waves generated during corona discharge are attached to the steel tower 1 side. As shown in FIG. 2, the current sensor 6 is connected to a current transformer 9 on an insulator metal fitting 8 on the ground side of an insulator 2 representing a steel tower.
In addition to being attached together, it may also be attached to the base of a steel tower in order to measure the leakage current of two or more insulator chains, an insulator suspension system, or the entire steel tower. The leakage current value due to insulator contamination is approximately several tens of mA to 500mA, and a Faraday element, a Hall element, a search coil, or the like is used as the current sensor 6 for detecting this, and detects the leakage current that gradually increases as the contamination progresses.
Furthermore, the radio noise radio waves are about 50 to 80 db, and the radio wave sensor 7 that detects them is composed of, for example, a small directional antenna and a detector, and is mounted on the steel tower arm facing the insulator chain to be measured as shown in the figure. In addition, it can be installed at an appropriate location such as the body of a steel tower. The detection frequency of the radio wave sensor 7 is the broadcasting station,
It is preferable to use the 1600 kHz to 1610 kHz band, which is the boundary of the frequency band used by radio stations, etc., is less susceptible to disturbance, and can clearly receive radio noise waves.

The outputs of these current sensors 6 and radio wave sensors 7 are guided to a converter 12 via cables 10 and 11 and converted into optical signals, and then sent to an overhead ground optical fiber cable connected to an optical fiber cable junction box 13. 5 will be transmitted to the control center 4. Note that when a Faraday element is used as the current sensor 6, an optical fiber cable is used as the cable 10, and when other elements are used, the cable 10 has two wires: an optical fiber cable for signal transmission and a power supply cable. or composite cables shall be used. It is preferable that the power source for such equipment on the tower side be an independent type that combines solar cells and storage batteries to reduce the effects of accidents such as lightning strikes, but if there is a nearby power distribution line, it may be supplied from there. You may also do so. Further, the data detected by the current sensor 6 and the radio wave sensor 7 may be transmitted to the control center 4 in real time, but in order to reduce the amount of transmitted information and power consumption, Preferably, a level setting device is provided so that data is transmitted only when the intensity of radio noise waves exceeds a set level. Further, when only the current sensor 6 is used, the configuration of the device can be simplified although reliability is slightly lowered.

On the other hand, the control center 4 includes a photoelectric converter 14 that converts the transmitted optical signal into an electrical signal, an arithmetic processor 15, a CRT 16, a printer 17, and an alarm device 18.
etc. are provided. The arithmetic processor 15 calculates the state of corona light emission due to contamination of the insulator 2 of each steel tower 1 based on the transmitted information regarding the leakage current value from the current sensor 6 and the information regarding the radio noise radio wave from the radio wave sensor 7. The specific process will be explained in the next operation section.

(Function) In the power transmission line contamination corona monitoring system of the present invention configured as described above, the current sensors 6 attached to many steel towers 1 distributed over a wide area detect the value of leakage current flowing on the insulator surface, and also detect the value of the leakage current flowing on the insulator surface. As described above, the sensor 7 detects radio noise waves generated during corona discharge, converts them into optical signals, and transmits the signals to the control center via the overhead ground optical fiber cable 5. Arithmetic processing unit 15 of control center 4
determines that a contamination corona has occurred when the intensity of the radio noise radio waves detected by the radio wave sensor 7 exceeds the level set by the level setting device, as shown in the flowchart of FIG. By counting the number of times, the frequency of corona occurrence is calculated. Then, the corona luminescence frequency due to contamination is calculated from the leakage current value detected by the current sensor 6 and the frequency of corona occurrence.

In other words, as shown in Figure 4, there is a correlation between the leakage current value and the corona luminescence frequency, and by applying the relationship in Figure 4 while correcting the correlation formula using data on the frequency of corona occurrence, The contamination corona luminescence frequency of the insulator is calculated. Here, the fouling corona luminescence frequency is the frequency of occurrence plus its intensity, and corresponds to the number of insulators in which fouling corona has occurred. Thereafter, it is determined whether or not the contamination corona luminescence frequency exceeds the allowable level and is within the area requiring cleaning, and a cleaning command and the position of the steel tower to be cleaned are output to the CRT 16, printer 17, alarm 18, etc. Since such calculations are automatically performed on the insulators of a large number of steel towers distributed over a wide area, it becomes possible to intensively monitor a large number of insulators in real time.

(Effects of the Invention) As is clear from the above description, the present invention is capable of immediately detecting contaminated corona occurring on the insulators of power transmission lines distributed over a wide range of areas, and is capable of responding to the luminous intensity of the contaminated corona. Since a cleaning command can be issued immediately, maintenance work such as insulator cleaning can be performed in a timely manner and efficiently. Furthermore, unlike the conventional monitoring method using a pilot insulator, the present invention allows the luminous intensity of the contaminated corona of a real insulator to be ascertained, so that a cleaning command can be issued more accurately. Therefore, the present invention greatly contributes to the development of industry as a method for monitoring contaminated power transmission lines and corona that solves the conventional problems.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the entire system used in the present invention, FIG. 2 is a side view showing how the current sensor is installed, and FIG. 3 is a flowchart explaining the processing contents in the arithmetic processing unit of the control center. FIG. 4 is a graph showing the correlation between corona luminescence frequency and leakage current. 1: steel tower, 2: insulator, 4: control center, 5: overhead ground wire optical fiber cable, 6: current sensor, 7: radio wave sensor, 15: arithmetic processing unit.

Claims (1)

[Claims] 1. A current sensor 6 that detects the leakage current flowing on the insulator surface and a radio wave sensor 7 that detects the radio noise radio waves generated from the insulator 2 during corona discharge are installed on the pylon 1 side of the power transmission line, and the measured values from these are calculated fictitiously. It is transmitted to the control center 4 via the ground wire optical fiber cable 5, and in the control center 4, the arithmetic processing unit 15 performs
The frequency of corona occurrence is calculated by counting the number of times the intensity of radio noise radio waves exceeds a set value, and then the corona luminescence frequency is calculated while correcting the correlation formula between the leakage current value and the corona luminescence frequency by the corona occurrence frequency.
A power transmission line contaminated corona monitoring method characterized in that a cleaning command is issued when the corona luminescence frequency exceeds a set level.