JPH03199981A - System for spotting fault section of transmission line - Google Patents

Abstract

PURPOSE:To judge a section wherein a fault occurs when the phase differences of neighboring two points are largely different by providing a plurality of detecting points along transmission lines, and detecting the phase difference between a voltage with respect to the ground and a current with respect to each phase of the transmission line at each detecting point. CONSTITUTION:A plurality of sensors 2 for spotting a faulty section are provided at a specified interval along transmission lines 1 for the phases of R, S and T of the transmission lines 1. The sensors 2 are suspended from the transmission lines in the vicinity of a steel tower 3. The phase difference between the voltages with respect to the ground in the transmission line 1 to which the sensor belongs and the current with respect to the voltage is detected. The information of the current phase is transmitted to a receiving device 4 on the side of a ground-potential part by radio. The device 4 evaluates the presence or absence of a fault in the transmission line with a part between the sensors 2 and 2 as a unit. The result of the evaluation is transmitted to the upper part of the steel tower 3 through an approach optical fiber 5 and further transmitted to a remote point through a composite overhead earth wire 6 of an optical fiber. The results are collected at a central monitoring station.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fault section locating method for detecting sections where short circuit accidents, ground faults, etc. occur in power transmission lines, and in particular, a fault section locating method for detecting sections where short circuit accidents, ground faults, etc. occur in power transmission lines, and in particular, a fault section locating method for detecting sections where short circuit accidents, ground faults, etc. The present invention relates to a method for locating faulty sections of power transmission lines that utilizes information.

[Prior Art] Power transmission lines are necessary and indispensable equipment for today's power supply operations, and accidents or failures of this equipment can have an extremely serious impact on today's highly electrified society, and in some cases can cause damage in all directions. It is possible that the social functions of people may be paralyzed.

For this reason, to protect power transmission lines from lightning strikes, etc., overhead ground wires have been laid, and extremely reliable insulation support methods have been adopted to prevent flash faults. We have not yet reached the point of completely eliminating accidents.

Therefore, in the event that such an accident occurs on a power transmission line, the next best challenge is to quickly establish the location of the accident.

Conventionally, so-called fault rogators (FL), such as a surge reception method or a pulse radar type, have been employed as a method for detecting the location of an accident on a power transmission line. These measures the arrival time of a fault surge, etc. at both ends of a power transmission line such as a substation, and calculate the distance to the fault point.

[Problems to be Solved by the Invention] However, these conventionally employed PLs have a drawback in that it is difficult to accurately locate failure points in power transmission lines having multi-branch lines.

SUMMARY OF THE INVENTION An object of the present invention is to provide a power transmission line fault section locating method that eliminates the drawbacks of the prior art described above and enables accurate fault position location even in a power transmission line with a complicated configuration.

[Means for Solving the Problems] The present invention provides a power transmission line failure section locating method for detecting sections where short circuit accidents, ground faults, etc. occur on power transmission lines, and a plurality of detection points are provided along the power transmission line. At each detection point, the phase difference between ground voltage and current is detected for each phase of the power transmission line, and if the phase difference between two adjacent points of each phase is significantly different, it is determined that a failure has occurred in that section. It is something.

This method installs sensors that detect the phase difference of the current with respect to the ground voltage of each phase on the electric wire at the plurality of detection points mentioned above, and transmits the detection results of each sensor to the ground potential by wireless or optical fiber transmission. It is preferable to send the information to

[Operation] At each of the plurality of detection points along the power transmission line, the relative phase difference of the current between two adjacent points on the same wire is monitored for all the wires of each phase of the power transmission line. When a ground fault occurs in a power transmission line, fault currents flowing in opposite directions (that is, opposite phases) are detected at the detection points on both sides of the fault point, and the relative phase difference is It's going to be very different. Therefore, it can be determined from this relative phase difference that a failure has occurred in the section.

In order to detect the phase difference of current between two adjacent points of each phase, common phase information or time information is required as a reference, but it is convenient to use the phase of the ground voltage of each phase as a reference. It is. Therefore, each sensor in a specific embodiment of the present invention detects the phase difference of the current on the electric wire of each phase with respect to the ground voltage of that phase. The detection results of each sensor are
Considering that the power transmission line is always charged at a high voltage, it will be sent to the ground potential section by wireless or optical fiber transmission and evaluated.

[Example] Hereinafter, the power transmission line failure section locating method of the present invention will be described in detail using figures showing examples.

FIG. 1 is a block diagram showing an embodiment of the power transmission line failure section locating method of the present invention, and FIG. 2 is an explanatory diagram of ground voltage and current waveforms showing the operation thereof.

In each of the R, S, and T phases of the power transmission line 1, a plurality of sensors 2 for locating a fault area are installed at predetermined intervals along the power transmission line 1. In this embodiment, these sensors 2 are suspended from the power transmission line 1 near the steel tower 3, and detect the ground voltage of the power transmission line 1 to which they belong and the phase difference of the current with respect to this voltage, and calculate the current. It has a function of wirelessly transmitting phase information to the receiving device 4 on the ground potential side. The receiving device 4 evaluates whether or not there is a failure in the power transmission line between each sensor 2 based on the received information. This evaluation result is transmitted to the top of the steel tower 3 via the approach optical cable 5,
Further, the data is optically transmitted to a remote point through an optical fiber composite overhead ground wire (OPGW>6) and collected at a central monitoring station (not shown).

Now, if a ground fault occurs at the 0 point on the T-phase power transmission line 1 in Figure 1, the sensors A and B that sandwich the 0 point
As shown in Figure 2, the flow direction is opposite (
That is, the fault current I (in opposite phase) 1. I2 flows.

Therefore, R and S of the power transmission line 1.

The phase difference (absolute phase difference) measured by each sensor 2 of each phase is collected at a central monitoring station, and the relative current phase difference Δφ between adjacent sensors 2 belonging to the transmission line 1 of the same phase is calculated. By constantly monitoring the fault area, it is possible to locate the fault area.

In the case of this embodiment, the sensors 2, 2 of A and B are connected to ground voltages Vl, V2 and current I at the time of failure, respectively, as shown in FIG.
1. I2, each sensor 2 also measures an independently measured voltage V1. Current I i, I for V2
2 phase differences φ^ and φB are also calculated. Since the ground voltages v1 and v2 measured by the sensors 2 and 2 of A and B are equal, on the receiving device 4 side, the phase difference φ8 between the current measured by the sensor A and the current measured by the sensor B The phase difference φB
By calculating the difference (φB - φA), the current ■1
The phase difference Δφ (Δφ − φB − φ8) between and 12 is detected, and Δ
The section where φ is larger is designated as the section where the failure occurs.

FIG. 3 shows an example of the configuration of the sensor 1 of the above-mentioned power transmission line failure section locating method.

Inside the sensor case 21 that is suspended from the power transmission line 1,
A current detection circuit 23 connected to the Rogowski coil 22 inserted into the power transmission line 1 and a voltage detection circuit 24 for detecting the ground voltage from the charging current lx flowing into the stray capacitance Cx of the sensor case 21 with respect to the ground are provided. It is being Also, inside the sensor case 21, based on the voltage information from the voltage detection circuit 24 and the current information from the current detection circuit 23, an absolute phase difference (φA) between the current and the voltage is determined.

a phase difference detection circuit 25 for detecting φB), and a wireless transmission 8 for transmitting the results obtained from the phase difference detection circuit 25.
126 and a transmitting antenna 27 are provided.

The power supply for each component circuit inside the sensor case 21 is provided by a power supply current transformer 28 attached to the power transmission line 1 and a DC power supply circuit 29 inside the sensor case 21 that is not connected to this.
It is obtained from the constant load current flowing through the power transmission line 1. The DC power supply circuit 29 has a built-in storage battery, and since it supplies power to each component circuit in the case while charging the battery, maintenance such as battery replacement is not required.

The converted ground voltage from the voltage detection circuit 24 and the detected current from the current detection circuit 23 are input to a phase difference detection circuit 25, which calculates the phase difference between the current and the voltage (φA,
φB) is detected. The phase difference information from the phase difference detection circuit 25 is transmitted to the receiving device 4 by the radio transmitter 26 and the transmitting antenna 27, where the relative phase difference Δφ between φ^ and φB is calculated. This calculation result is further applied to the receiving device 4.
From there, it is optically transmitted to a central monitoring station at a remote location via an approach optical cable 5 and an optical fiber composite overhead ground wire 6.

In the above embodiment, the current phase of each sensor is detected based on the ground voltage of the electric wire 1. The reason for this is that the sensor 2
As shown in the figure, since the current is measured individually and transmitted wirelessly, it is necessary to take time correspondences between the sensors. Therefore, time information can also be used as a common reference between sensors.

Further, in the above embodiment, the detection results are transmitted wirelessly from the sensor 2 to the receiving device 4, but the detection results may also be transmitted using an optical fiber.

[Effects of the Invention] As explained above, according to the power transmission line failure section locating method of the present invention, it is possible to install a detection sensor in the middle of a power transmission line, obtain detailed failure information, and also Because the direct detection sensor is installed above the cable, it has the extremely remarkable effect of being able to accurately locate the fault point even on power transmission lines with multi-branch lines, where it is difficult to locate fault points using conventional FLs. It has the following.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the power transmission line failure section locating method of the present invention, FIG. 2 is an explanatory diagram of voltage and current waveforms to explain the operation of FIG. 1, and FIG. FIG. 2 is a diagram illustrating a configuration example of a sensor for locating a faulty section that can be used in the electric wire faulty section locating method. In the figure, 1 is a power transmission line, 2 is a sensor for fault area location, 3 is a steel tower, 4 is a receiving device, 5 is an approach optical cable, 6 is an optical fiber composite overhead ground wire, 21 is a sensor case, 22
is a Rogowski coil, 23 is a current detection circuit, 24 is a voltage detection circuit, 25 is a phase difference detection circuit, 26 is a wireless transmitter,
27 is a transmitting antenna, 28 is a power supply current transformer, 29
indicates a DC power supply circuit. 0

Claims (1)

[Claims] 1. In a method for detecting sections where short circuit accidents, ground faults, etc. occur on power transmission lines, a plurality of detection points are provided along the power transmission line, and each detection point Transmission line fault section locating, which detects the phase difference between ground voltage and current for each phase, and determines that a fault has occurred in the section if the phase difference between two adjacent points of each phase is significantly different. method. 2. At the multiple detection points mentioned above, install sensors that detect the phase difference between the ground voltage and current of each phase on the wire, and transmit the detection results of each sensor to the ground potential section by wireless or optical fiber transmission. 2. The transmission line fault section locating method according to claim 1, wherein: