JP3070858B2 - Fault section detection method for multiple transmission lines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fault section detection method for a large number of transmission lines.

[Conventional technology]

FIG. 3 shows an example of a conventional configuration of a transmission line fault section detection system using an optical fiber as a transmission line and targeting many lines. As shown in the figure, in the conventional system, there are a plurality of power transmission systems such as 19a and 19b, and when a single processing device (master station) 14 is provided, a plurality of optical couplers 16a
And a transmission request signal are transmitted to the terminal stations 17a to 17b installed in the transmission systems 19a and 19b. In the figure, reference numeral 15 denotes a photoelectric converter, and reference numerals 18a to 18e denote optical fiber signal transmission lines.

As shown in FIG. 4, the optical fibers 22a to 22d are connected in series, the processing device 20 is connected to the terminal station 24, and the failure signal and the transmission request signal are transmitted to each of the terminal stations 24a to 24d for power transmission. A system for collecting fault information of the systems 23a and 23b was also considered.

[Problems to be solved by the invention]

However, in the conventional system as shown in FIG.
When the number of transmission lines increases, the transmission distance between the photoelectric converter 15 and the terminal station 17 becomes extremely short due to the loss of the optical coupler, and is not practically usable.

In addition, in the system shown in FIG. 4, the number of power transmission systems that can be connected in series is limited, which is a great limitation when constructing a system.

This will be specifically described with a combination of a multimode optical fiber and an optical signal wavelength of 0.85 μm, which are often used in the conventional system.

LED (light emitting diode) as light source, PD as light receiving element
(When using a photodiode ・ Transmission loss of multimode optical fiber 3dB / km ・ Emission level of LED -18dBm ・ Reception level of PD --35dBm ・ Insertion loss of optical coupler 4.5dB ・ Transmission margin of system 3dB (Processing device ( The optical fiber transmission loss between the optical coupler and the optical coupler and between the optical coupler and the optical coupler is treated as 0 dB because of the short transmission distance.) The transmission distance between terminal stations is obtained as follows.

a. Two transmission lines (one optical coupler) 35-18-4.5-3 = 9.5 dB Therefore, the distance is 9.5 / 3 = 3.2 km. b. Three transmission lines (optical coupler) 35−18−4.5−4.5−3 = 5dB Therefore, the distance is 5 ÷ 3 = 1.7km. C. When there are four transmission lines (three optical couplers) 35−18−4.5 −4.5−4.5−3 = 0.5dB Therefore, the distance is 0.5 ÷ 3 = 0.2km. From the above calculation results, it is possible to satisfy the standard transmission distance of 2-3km between the processing device and the terminal station in the conventional system. Is up to two systems. Further, in the case of three or more systems, the value is not practically usable.

Therefore, an object of the present invention is to solve such a conventional problem.

[Means for solving the problem]

In order to achieve this object, the fault section detection method in the multiple lines of the transmission line according to the present invention includes a terminal station provided in a plurality of towers of each transmission system, and a plurality of transmission stations provided in each transmission system. An optical transmission line for connecting a terminal station, a logic circuit connected to each optical transmission line via a photoelectric converter provided for each optical transmission line, a processing device connected to the logic circuit, A detector connected to the terminal station to detect a failure that occurs frequently, wherein the terminal station transmits a failure signal in a time division manner by a transmission request signal by polling from the processing device, and the logic circuit By branching and controlling a transmission request signal from the processing device and a failure signal transmitted through each of the photoelectric converters, the processing device collects data and determines a failure section. [Action] In the present invention, an optical signal is converted into an electric signal, a logic circuit for branching the signal is added, and polling is performed in a time-division manner so that data such as a failure signal and a transmission request signal do not collide in an optical fiber. This allows data processing on a plurality of lines without being affected by the transmission distance and system construction.

〔Example〕

 Hereinafter, the present invention will be specifically described based on examples.

FIG. 1 is a block diagram showing an embodiment of a transmission line fault section detection system according to the present invention. In FIG.
2 is a logic circuit showing a specific configuration in FIG. 2, 3a and 3b are photoelectric converters, 4a to 4b are terminal stations, 5a to 5d are detectors, 6a to 6d are magnetic sensors, 7a and 7b are power transmission systems, 8a to 8d indicate optical fibers.

Specifically, terminal stations 4a, 4a,
4b, 4c, 4d are provided. Fault currents detected by the magnetic sensors 6a, 6b, 6c, 6d are determined by the detectors 5a, 5b, 5c, 5d. The terminal stations 4a, 4b, 4c, 4d are connected by optical fibers 8a, 8b, 8c, 8d, and further the terminal stations 4a, 4c are connected to photoelectric converters 3a, 3b, and the photoelectric converters 3a, 3b Is the logic circuit 2
Is connected to the processing apparatus 1 via the.

The terminal stations 4a, 4b, 4c, and 4d collect fault currents obtained by the magnetic sensors 6a, 6b, 6c, and 6d with the detectors 5a, 5b, 5c, and 5d, respectively, and transmit a transmission request signal by polling from the processing device 1. Thus, the failure signal is transmitted to the processing device 1 via the optical fibers 8a, 8b, 8c, and b8d.

The fault signal transmitted between the terminal station 4 and the processing device 1 is converted into an electrical signal by the photoelectric converters 3a and 3b, and then the fault signal A1 is output by the OR circuit 9 as shown in the block diagram of FIG. And the failure signal A2 are combined.

On the other hand, the transmission request signal is output from the processing device 1, branched by the buffer circuit 10, and transmitted to each terminal station 4.
B1 and a transmission request signal B2 are transmitted via the photoelectric converters 3a and 3b. The failure signals A1 and A2 are returned from the terminal station 4 by the transmission request signals B1 and B2.

The failure signals A1 and A2 are transmitted from each terminal station 4 in a time division manner in response to a transmission request from the processing device 1. The failure signal from the terminal station 4 corresponds to the polling transmission request from the processing apparatus 1 on a one-to-one basis, and only the terminal station 4 at the designated address of the processing apparatus 1 is returned.

The opto-electric converter start signals D1, D shown in the block diagram of FIG.
2 and the opto-electrical converter activation completion signals E1 and E2 are output or input from the processing device 1 when transmitting a transmission request signal from the processing device 1 to the terminal station 4, and are transmitted through the buffer circuit 12 and the OR circuit 13, respectively. Thus, a transmission request signal (optical signal) transmitted to the terminal station 4 is controlled.

Similarly, the optical carrier detection signals C1 and C2 detect the carrier of the failure signal (optical signal) returned from the terminal station 4, and notify the processing device 1 via the OR circuit 11 that the signal has been returned from the terminal station 4. Output.

The processing device 1 determines the presence or absence of a fault current for each detector based on the fault signal transmitted from the terminal station 4. From this result, a fault point is determined between a detector (pylon) that has detected a fault current and a detector (pylon) that has not detected the fault current, and the processing device 1 determines a fault zone between the detector (pylon) closest to the fault point. Display as

In the above embodiment, the number of power transmission systems is not limited to two as shown in the block diagram of FIG. 1, but may be a plurality of power transmission systems.

The signal to be transmitted is not limited to the fault current, and it is also possible to transmit a detection signal of a lightning flash, an aviation obstacle light, or the like.

〔The invention's effect〕

As described above, the present invention uses the time-division transmission method by polling, individually requests transmission to the terminal station, performs optical-electric conversion, and performs the branching of the transmission request and the failure information by the logic circuit. Therefore, the transmission distance is not shortened when processing data having a large number of lines, and the monitoring and maintenance of the transmission line can be speeded up.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a transmission line fault section detection system according to the present invention, FIG. 2 is a block diagram of a logic circuit in the embodiment of the present invention, and FIGS. It is a block diagram of a fault section detection system. 1: processing unit, 2: logic circuit 3a, 3b: photoelectric converter, 4a, 4b, 4c, 4d: terminal station 5a, 5b, 5c, 5d: detector, 6a, 6b, 6c, 6d: magnetic sensor 7a , 7b: power transmission system, 8a, 8b, 8c, 8d: optical fiber 9, 11, 13: OR circuit, 10, 12: buffer circuit 14: processing device, 15: photoelectric converter 16a, 16b: optical coupler ( 17a, 17b, 17c, 17d: Terminal station 18a, 18b, 18c, 18d, 18e: Optical fiber 19a, 19b: Transmission system, 20: Processing unit 21: Opto-electrical converter 22a, 22b, 22c, 22d: Optical fiber 23a, 23b: Transmission system 24a, 24b, 24c, 24d: Terminal station

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01R 31/08 G08C 15/00 G08C 15/06

Claims (1)

(57) [Claims] 1. A terminal station provided on a plurality of towers of each power transmission system, an optical transmission line provided for each power transmission system and connecting a plurality of terminal stations of each power transmission system, and provided for each optical transmission line. Logic circuit connected to each optical transmission line via the opto-electrical converter, a processing device connected to the logic circuit, and a detector connected to the terminal station for detecting a failure that occurs frequently. Wherein the terminal station transmits a failure signal in a time-sharing manner by a transmission request signal by polling from the processing device, and the logic circuit transmits the transmission request signal from the processing device and each of the photoelectric converters. A fault section detection method for multiple lines of a transmission line, wherein the fault signal transmitted via the control unit is branched and controlled to collect data in the processor and determine a fault section.