JPH0738867Y2 - Transmission line failure direction detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a failure direction detection device which is installed in the middle of a power transmission line and detects in which direction a failure has occurred from the installation position.

[Prior Art] Conventionally, there have been the following methods for detecting a failure direction of a power transmission line.

In a system in which one end of the transmission line is a neutral point high resistance grounded power supply and the other end is an ungrounded load, a large current flows from the power supply to the fault point.Therefore, this induction causes a current to flow to the overhead ground wire at a certain point. If the current exceeds a certain level, the fault is located on the load side.

In the same transmission line, a large zero-phase current flows from the power source to the fault point, so this is observed at a certain point, and if the zero-phase current is above a certain level, it is identified as a fault on the load side.

If there are power sources at both ends of the transmission line, the failure direction cannot be detected by the above two methods, and one end and two midway points (G
w, zero phase), a current sensor is provided, these pieces of information are collected in one place using an optical fiber or the like, and the phases are compared to determine whether the sensor section is inside or outside the sensor section.

[Problems to be solved by the invention] However, the above-mentioned failure direction locating device determines that a failure on the power supply side is a failure on the load side from the sensor mounting device to about 5 steel towers, or a failure on the power supply side is a failure. I didn't detect it, so I was worried whether it was working properly. Moreover, there is a problem that it cannot be applied to the transmission lines of both power sources.

Similarly, the above-mentioned fault direction locating device also has a problem that it cannot be applied to the transmission lines of both power sources.

The above-mentioned failure direction locating device requires a data transmission path from one sensor to the other sensor, so that there is a problem that the device becomes large in size and high in cost.

An object of the present invention is to solve the above-mentioned conventional technique and to provide a failure direction detection device capable of locating a failure direction by mounting a sensor at only one point for both power supply systems. .

[Means for Solving the Problems] The transmission line fault direction detection device of the present invention detects the current of the overhead ground wire provided at one point of the transmission line line consisting of the three-phase AC transmission line and the overhead ground wire current. A current sensor for detecting, a voltage sensor for detecting the voltage of one phase of the three main lines of the three-phase AC transmission line, and an evaluation device for determining the failure direction from these information, the evaluation device is a voltage A fault phase detector that detects the occurrence of a fault and a fault phase from the voltage information of the sensor, and an overhead ground line current phase after the fault from the current information of the current sensor based on the phase before the fault of the mains voltage based on the voltage information of the voltage sensor A phase comparator to detect the, the calculated value of the zero-phase current phase flowing into the failure point when assuming a failure point on one side based on the installation point of the voltage sensor from the information of the failure phase, and the above Calculated from overhead ground wire current phase information If the phases of the zero-phase currents are compared, the phases are judged to be in the same direction as the assumed direction if the phases are approximately the same, and if the phases are approximately opposite, the assumed direction and the opposite direction are defective. And a determination circuit for determining the direction.

[Operation] The failure phase is determined from the magnitude and phase of the voltage after the failure obtained from the voltage sensor, the zero-phase current flows from the power supply side to the failure point, and the current phase flowing through the overhead ground wire is the zero-phase current. It is well known that there is a predetermined relationship with the phase.

Therefore, using the voltage waveform before the failure obtained from the voltage sensor as the phase reference, determine the failure phase from the magnitude and phase of the voltage after the failure obtained from the voltage sensor, and determine the failure phase from the installation location of the sensor. The zero-phase current phase when a failure occurs on one side is calculated in advance, and the calculated value of the zero-phase current phase obtained from this and the phase of the overhead ground current after the failure is approximately the same phase or approximately the opposite phase. It is possible to know which side the failure point is from the installation location of the sensor by comparing

[Embodiment] The apparatus configuration of the present invention is shown in FIG.

A current sensor 1 installed on the overhead ground wire 8 of the transmission line and a voltage sensor 2 installed on one of the three three-phase AC transmission lines 9
And an evaluation device 3 for determining the failure direction from the information. The evaluation device 3 is provided on the steel tower 10, and data transmission to the evaluation device 3, that is, the current sensor 1 is performed.
The transmission of the overhead ground wire current information from the above and the main line voltage information from the voltage sensor 2 is performed by using the wireless transmission / reception device in the present embodiment, but may be performed by an optical transmission / reception device using light.

The circuit configuration of the evaluation device 3 is shown in FIG.

The evaluation device 3 that determines the failure direction from the overhead ground wire current information and the mains voltage information includes a waveform memory 4 and a failure phase detector 5.
And a phase comparator 6 and a determination circuit 7.

The waveform memory 4 receives mains voltage information from the voltage sensor 2, sequentially overwrites and records the received voltage information, and always records past waveform data up to about 10 cycles at a commercial frequency. The fault phase detector 5 calculates the voltage effective value (average value) from the voltage waveform cycles obtained from the waveform memory 4 up to a few cycles before, and compares this with the effective value in the normal state, so that “the occurrence of a failure” occurs. Is detected, and the "failure phase" is detected from the magnitude of the effective value and the phase difference before and after the occurrence of the failure. The phase comparator 6 receives the overhead ground wire current information from the current sensor 1 and the voltage waveform cycle information from the waveform memory 4,
From these, the phase difference of the “overhead ground wire current phase after failure” with respect to the voltage phase before failure occurrence (that is, the overhead ground wire current phase after failure with reference to the voltage phase before failure occurrence) is detected.

The determination circuit 7 determines, based on the fault phase detected by the fault phase detector 5 and the phase difference (fault phase information) obtained by the phase comparator 6,
The failure direction is determined as follows.

In the determination circuit 7, the voltage before the failure of the main line on which the voltage sensor 2 is installed is used as the “phase reference”, and the “voltage sensor installation point of one side from the installation point of the voltage sensor 2, here, the“ voltage sensor installation point ”when the failure occurs The value of the zero-phase current phase φ ₁ ”is calculated according to the failure phase. This zero-phase current phase φ ₁ may be called from the one calculated in advance and stored as a numerical table.

On the other hand, the main phase zero-phase current phase φ ₂ is calculated from the overhead ground line current phase after the failure with reference to the voltage phase before the failure by the voltage sensor 2, and the main line zero-phase current phase φ ₂ and the above zero phase are calculated. The current phases φ ₁ are compared, and if φ ₂ is approximately in phase with the zero-phase current phase φ ₁ , it is considered as a failure on the left side from the installation point of the voltage sensor 2, and φ ₂ is approximately in reverse phase with the zero-phase current phase φ _1. If there is, it is judged as a failure on the right side.

When comparing φ ₁ and φ ₂ , if there is no error etc., it is sufficient to compare in-phase or anti-phase, but in reality there are errors etc. Since they are 180 ° different from each other, errors and the like do not actually pose a problem.

[Effects of the Invention] As described above, according to the present invention, a failure direction is caused by a pair of overhead ground current sensor, transmission line voltage sensor and evaluation device installed at only one point in the transmission line of both power sources. Can be standardized.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a failure direction detecting device of the present invention, and FIG. 2 is a circuit configuration diagram showing an evaluation device example in the failure direction detecting device. In the figure, 1 is a current sensor, 2 is a voltage sensor, 3 is an evaluation device, 4 is a waveform memory, 5 is a fault phase detector, 6 is a phase comparator, 7 is a judgment circuit, 8 is an overhead ground wire, and 9 is three. The phase alternating current transmission line is shown.

Claims (1)

[Scope of utility model registration request] 1. A current sensor for detecting a current of an overhead ground wire, which is provided at one point of a power transmission line consisting of a three-phase AC power transmission line and an overhead ground wire current, and three of the three-phase AC power transmission wires. It consists of a voltage sensor that detects the voltage of one phase of the main line and an evaluation device that determines the failure direction from these information, and the evaluation device detects the occurrence of a failure and the failure phase from the voltage information of the voltage sensor. Fault phase detector, a phase comparator that detects the overhead ground line current phase after a fault from the current information of the current sensor based on the phase before the fault of the mains voltage based on the voltage information of the voltage sensor, and the phase of the fault phase From the information, the calculated value of the zero-phase current phase flowing into the failure point when the failure point is assumed on the one side based on the installation point of the voltage sensor, and the zero calculated from the overhead ground wire current phase information. Compare the phase of the phase current, If the phases are substantially the same, it is determined that the failure direction is the same as the assumed direction, and if the phases are substantially opposite, the judgment circuit that determines the failure direction is the opposite direction. A power line failure direction detection device.