JPS60169775A - Apparatus for locating failure point of power- transmission line - Google Patents

Abstract

PURPOSE:To make it possible to realize the enhancement of noise resistance and the protection of a signal processing apparatus from surge, by simplifying the signal processing apparatus by dispensing with a synchronous circuit and using an optical fiber in signal transmission. CONSTITUTION:The surge wave generated from the failure point F at a distance lA from a terminal A and at a distance lB from a terminal B is propagated to both directions and propagated through an optical fiber while connected to a light signal by a sensor 2 and a photoelectric converter 6. On the basis of the signal propagation delay times in the optical fibers in the A-terminal side and the B-terminal side and time when the surge wave is generated, times of surge wave form signals from both terminals reaching a signal processing apparatus 8 are signal propagation delay times in the photoelectric converter 6 and the signal processing apparatus 8 and take the same value at both terminals. In this case, the center between terminals A, B is set to zero and the A-terminal side from the center to positive while the B-terminal side to negative and, when arrival time difference of surge wave form signals from both terminals is measured, the failure point F can be calculated.

Description

[Detailed Description of the Invention] [1] Technical field of the invention A device for detecting a failure in a power transmission line such as an overhead power transmission line or a conduit aerial power transmission line due to a lightning strike or a ground fault, and locating the failure point. Regarding.

[2] As shown in Fig. 1, the conventional power transmission line failure point locating device locates the failure point based on the propagation delay time difference between when the surge wave generated at the failure point F propagates through the transmission line 1 and reaches both ends. A sensor 2 that detects surge waves at both ends, a signal processing device 8 that processes signals from the sensor, and a synchronous signal transmission line 4 that uses a microwave line or the like to measure the time difference between the devices. Requires. The signal processing device measures the arrival time of the °C surge wave using the synchronization signal as a reference, and calculates the failure point from the difference in arrival time at both ends and the transmission line propagation speed of the surge wave. Here, the propagation speed of the surge wave is approximately the speed of light, and the measurement of the arrival time difference must be performed with extremely high precision. Therefore, the synchronization method of the signal processing devices at both ends, which serves as the reference, is important.

[3] Problems with the conventional technology In the failure point locating device, the synchronization signal that serves as a reference when measuring the arrival time of surge waves at both ends is important, but the microwave line etc. that transmits this synchronization signal itself is also important. Since this involves a delay, it is necessary to measure the synchronization signal transmission delay time in advance. From end A to end B, or from end B to A
A because it is impossible to measure the transmission delay time to the end.
A synchronizing signal from A to B, or from B to A, with the delay time set to 2 when a signal is transmitted from end B to end B, and the signal is looped back at end B and transmitted again to end A. This is the transmission delay time. In the above method, it is necessary to measure the transmission delay time and set the constants of the signal processing device for each location where the locating device is installed. Also, from end A to end B,
The transmission delay time from the B end to the A end is not necessarily the same. Furthermore, since high-speed and high-precision synchronous signal processing circuits are required at both ends, the device becomes expensive.

[4] Purpose of the Invention The purpose of the present invention is to solve the above problems of the prior art, simplify the signal processing circuit, improve fault location accuracy, and eliminate the need to measure the transmission delay time of synchronization signals. That's true.

[5] Configuration of the Invention An outline of the configuration of the failure point locating device of the present invention is shown in FIG. 2. 1
is a power transmission line, and at both ends there are a sensor 2 that detects surge waves and an electro-optical converter (hereinafter referred to as E) that converts the output of the sensor into light.
10 converter) 6, an optical fiber cable 7 that transmits optical signals, and a signal processing device 8 that processes optical signals from both ends and calculates the position of a failure point F. Here, the sensor 2 is a conventionally used CT (Current
Transformer) etc. can be used. Furthermore, the propagation delay time difference between the optical signals propagating through the optical fiber from both ends can be measured in advance and therefore is known.

[6] Embodiment An embodiment of the use of the failure point locating device shown in FIG. 2 will be described in detail. Distance iA from end A in Figure 2, distance j from end B
The surge wave generated from the fault point F of ln travels in both directions at a speed τ
It is converted into an optical signal by a sensor and an E10 converter, and propagated through an optical fiber.

At this time, the signal propagation delay times in the optical fibers on the A end side and B end side are respectively τ4 and τB, and the surge waveform signals from both ends arrive at the signal processing device based on the time when the surge wave is generated. When the times are respectively tA and tB, the following holds true. Here, α is the signal propagation delay time within the sensor 2, the E10 converter 6, and the signal processing device 8, and is the same value at both ends. If X is 0 at the center of the AB end, and positive on the A end side from the center and negative on the B end side, then from formula (1), x = () B - No A)
/2= (tn t*+ (τ^−τs) l ・v/
2 ・−゛(2) holds true. Here, since τ^ and τB1τ are known, the failure point X can be calculated by measuring the arrival time difference (ts - tA) of the surge waveform signals from both ends.

FIG. 3 specifically shows the internal circuit of the signal processing device 8 in FIG. The signal is converted into a signal and input to the trigger circuit 10. The trigger circuit turns on the output signal when the surge waveform exceeds a certain fresh hold level. This signal nuts the R-87 lip-flop 11, turning output Q on and turning output Q off. Therefore, if the surge waveform arrives at the A end first, the input Q on the A end side of AND game 2 is ON and the input Q for the B end side remains ON until the surge waveform arrives at the B end. Since it is turned off at this point, AND gate 1
In the output of 2, the surge waveform arrives at the A end first, and then the B
It remains ON until the surge waveform arrives at the end. In other cases, it is always OFF.

Conversely, if the surge waveform arrives at the B end first, and then the surge waveform arrives at the A end, the output of the AND gate 13 will be the same until the surge waveform arrives at the A end. It turns on. The R-S flip-flop lla is connected to the output of the AND gate 2 through ζ, and is connected to the output of the AND gate 13. Therefore, the output Q of the R-S flip-flop lla turns ON only when the surge waveform arrives at the A terminal first. The OR gate 14 receives the surge waveform at the A end or B end, and then
It remains ON until the surge waveform arrives at the end. The up/down counter 16 counts up or down the output clock of the clock generation circuit 15 only while the output of the OR gate 14 is ON, according to the ON/OFF status of the output signal of the R-S flip-flop lla+7). In addition, if the up/down counter 16 is loaded in advance with the number of clocks corresponding to the offset time (τA - τB) in equation (2), if the counter value is 0, the failure point will be at the center, and if it is positive, the failure point will be at the A end. , if it is negative, it will be on the B end side. The fault point calculation circuit 17 detects that a fault has occurred when the output of the OR gate 14 turns ON, and then performs an OR gate.
After the output of the gate 14 is turned off, the counter value is read, and the counter value is converted into a distance according to equation (2) and output.

[7] Effects The failure point locating device according to the present invention eliminates the need for the synchronization circuit required in conventional devices, making it possible to configure the signal processing circuit extremely easily, and using optical fiber for signal transmission. By using this, it is possible to improve noise resistance and protect the signal processing device from surge. Another advantage is that it becomes unnecessary to measure the synchronization signal propagation delay time at the location where the locating device is installed, which was conventionally necessary. In particular, the distance between end A and end B is several 1
In the case of a pipeline aerial power transmission line with a length of approximately 0 m, by making the optical fibers from both ends to the signal processing device the same length, the effect of the offset time (τA - τB) in equation (2) is eliminated, resulting in extremely high accuracy. It becomes possible to locate the failure point.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a conventional failure point locating device. FIG. 2 is a configuration diagram of the failure point locating device of the present invention. FIG. 3 is a circuit configuration diagram inside the signal processing device of the fault point locating device of the present invention. ■...Power transmission line 2...Surge wave detection sensor 3...Signal processing device 4...Synchronization signal transmission line 5 -Electrical signal transmission lead wire 6...Electro-optical converter (E10 conversion Device 9 7... Optical fiber cable 8... Signal processing device 9... Optoelectrical converter (0/E converter) lO...
・Trigger circuit 11, lla... Flip 70 tube 12.13...
...AND game 4...OR gate 15-...clock generation circuit 16...up/down counter 17...fault 1 point calculation circuit (■

Claims (1)

[Claims] (1) In the power transmission line failure point locating device, sensors are installed at both ends of the power line K to detect the surge waveform that occurs when the power line fails, and these sensors convert electricity into light E1.
An O/E converter, a trigger circuit, and a flip-flop logic gate that connects the E10 converter via an electrical signal transmission lead wire and converts the light emitted from the E10 converter into electricity using an optical fiber cable. 1. A fault point locating device for a power transmission line, characterized in that it is configured to transmit data to a signal processing device comprising a clock generation circuit, an up/down counter, a fault point calculation circuit, and the like.