JP3024348B2 - Distribution line fault section detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accident section detecting device for detecting in which section of a distribution line path an accident has occurred in a distribution line automation system.

[0002]

2. Description of the Related Art A conventional example of an apparatus for detecting an accident section of a distribution line will be described. Distribution lines connected via circuit breakers at substations are divided into multiple sections by timed automatic section switches. When an accident occurs on a distribution line, the substation circuit breaker first shuts off. Then, the timed automatic switchgear of the distribution line is released without voltage. When the circuit breaker is turned on again after a first predetermined time after the cutoff, the timed automatic segmented switch is sequentially turned on after a delay of a second predetermined time from the power supply side. Then, when the power is applied to the accident section, the accident occurs again, so the circuit breaker performs the interruption again. Therefore, the accident section was determined by measuring the time from the re-input of the circuit breaker to the re-interruption.

[0003]

However, in the above-mentioned conventional apparatus for detecting an accident section of a distribution line, the circuit breaker of the substation is cut off after the occurrence of the accident, and the circuit is reclosed after a first predetermined time has elapsed, and the power supply side is timed. When the accident section was charged with timed turn-on from the automatic switchgear in order, the entire section was blackout again. Therefore, there is a problem that not only the power outage accident is prolonged but also the power is restarted in a healthy section, which inconveniences the power consumers.

[0004] The present invention is intended to solve the above-mentioned problem, and it is possible to judge an accident section without going through procedures of shutting down, reclosing, timed-in and re-shutting, to shorten a power outage time and to restore a healthy section. The purpose is to prevent power outages.

[0005]

In order to achieve the above object, an apparatus for detecting an accident section of a distribution line according to the present invention measures an arbitrary phase current of the distribution line at a plurality of slave stations installed on the distribution line. A phase current measuring device, a zero-phase current measuring device for measuring a zero-phase current of a distribution line, an inter-phase voltage measuring device for measuring an arbitrary inter-phase voltage of a distribution line, and a phase difference between a zero-phase current and an inter-phase voltage A phase difference measurement device, a phase determination device that determines whether the phase of the inter-phase voltage is normal or inverted based on the phase difference between the inter-phase voltage and the phase current, and a phase difference measurement device when the phase of the inter-phase voltage is inverted Invert the phase difference measured by
And a first communication device that communicates with the master station. The master station that collects information from the slave station includes a second communication device that communicates with the slave station, and a second communication device that communicates with the slave station. And a second arithmetic unit that determines an accident section based on phase difference information collected from a plurality of slave stations by the second communication device.

[0006]

According to the present invention, the fault point is determined from the phase difference information of the interphase voltage and the zero-phase current of each slave station collected by the master station from the plurality of slave stations provided on the distribution line in the above configuration, It is possible to judge an accident section without going through a procedure of disconnection, reclosing, timed-in and re-disconnection of a distribution line.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram in which one embodiment of the present invention is applied to a distribution line automation system. A plurality of slave stations 7 are installed on the distribution line 2 connected to the substation 1, and the voltage detection unit 5 is attached to the distribution line 2, and the inter-phase voltage is measured by an inter-phase voltage measurement device provided in the slave station 7. I do. Similarly, a phase current and a zero-phase current are measured from a current detection unit 6 attached to the distribution line 2. Each slave station 7 and the master station 3 are connected by a transmission line 4.

A more detailed configuration will be described with reference to FIG. In FIG. 2, an instrument transformer 14 serves as a voltage detecting unit.
Is used to measure an AC-phase voltage of a distribution line. Further, a photocurrent sensor 15 using the Faraday effect is used as a current detection unit. As for the phase current of the distribution line, the phase current measurement device 16 measures the B-phase current from the output of the photocurrent sensor 15 installed on the distribution line. In the slave station 7, the inter-phase voltage is determined by the inter-phase voltage measuring device 11 from the secondary voltage of the instrument transformer 14, and the zero-phase current is determined by the zero-phase current measuring device 12 from the output of the photocurrent sensor 15. That A
-C phase difference measuring device 1 that inputs a voltage between phases and a zero-phase current
At 3, the phase difference between the voltage and the zero-phase current is measured.

On the other hand, the phase difference between the AC phase voltage and the B phase current is measured by the phase determining device 17 to determine whether the phase of the AC phase voltage is normal. The determination method will be described in more detail. First, when the distribution line is normal, each phase voltage and each phase current are as shown in FIGS.
If the load of the distribution line is assumed to be resistive load, B phase current I _B and the B-phase voltage V _B is in phase, the V _B is from [pi / 2 delayed AC phase voltage V _AC, 3 I _B as shown in (C) than V _AC π / 2 delayed. Since the actual load is capacitive component and inductance I _B from 0 for V _AC -
in the range of π. On the other hand, when the _AC phase voltage VAC is in the opposite phase, each phase voltage and each phase current are as shown in FIG.
(A) and (B) as shown in FIG.
FIG. 4C shows the relationship between _B and the _CA voltage VCA. Considering the actual load capacity and inductance, I
_B falls in the range of 0 to + π with respect to V _CA. As described above, the phase of the AC phase voltage is determined by the phase determining device 17, and as a result, if the AC phase voltage is in the opposite phase, the zero phase obtained by the phase difference measuring device 13 by the first arithmetic device 18 is determined. The phase difference between the current and the AC phase voltage is corrected by adding or subtracting π.

On the other hand, the master station 3 uses the second communication device 10
From the first communication device 8 of the slave station 7 via the transmission path 4,
Collect phase difference information. Here, a ground fault occurred in Fig. 5.
The state of each detection signal in the case_ACIs the distribution line
AC phase voltage, I₀₁~ I₀₅Is the zero-phase power at each slave station.
Flow, θ₁And θ_TwoIs the interphase voltage V_ACAnd zero-sequence current I₀₁~ I₀₅
, And the arrow indicates the direction of the phase.
As shown in FIG. 5, in the section between No. 3 and No. 4 of the slave station 7,
Assuming that a ground fault has occurred,
Flows, the slave station 7 on the power supply side from the accident section
Zero-phase current I₀₁, I ₀₂And I₀₃And the slave station 7 on the load side
Zero-phase current I₀₄And I₀₅So that the phase differs greatly from
Become. In contrast, the inter-phase voltage measured by all slave stations is almost
There is no equal phase difference. Therefore, measure each slave station
The phase difference of the zero-phase current of each slave station based on the
By comparison, an accident occurs in the section where the phase difference changes greatly.
It can be determined that this has occurred.

As described above, the phase difference of the zero-phase current of each slave station is determined based on the voltage which is a common reference for each slave station, and the phase difference information is collected by the master station, and the zero-phase current is calculated by the master station. If the current phase difference is determined, the ground fault location can be reliably detected.

Although the above description has been made of an example in which the interphase voltage is between the A and C phases and the phase current is the B phase, the same fault section can be determined by using any other combination of the interphase voltage and the phase current. Further, the inter-phase voltage measuring device can be applied to an optical sensor voltmeter utilizing the Pockels effect. It should be noted that a high power measurement accuracy is not required when making an accident determination based on the phase difference between the voltage and the zero-phase current, so that a normal power supply transformer may be applied. Further, the zero-phase current can be measured by a zero-phase current transformer. A current transformer may be used for measuring the phase current.

[0013]

As is apparent from the above description, according to the distribution line fault section detecting apparatus of the present invention, in order to detect the fault section, the distribution line is cut off and reclosed, and the distribution section is timed in and off. Without going through the procedure described above, it is possible to easily determine the fault section in the distribution line from the phase difference between the interphase voltage and the zero-phase current collected by the master station from a plurality of slave stations provided in the distribution line, There is no need to power down the healthy section again,
In addition, the power outage time is significantly reduced, and the effect on customers can be minimized.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a distribution line automation system employing an embodiment of a distribution line accident section detection device according to the present invention.

FIG. 2 is a block diagram showing a detailed configuration of an embodiment of a distribution line fault section detection device according to the present invention.

FIGS. 3A to 3C are vector diagrams showing a relationship among each phase voltage, each phase current, and an interphase voltage when the distribution line is normal;

FIGS. 4A to 4C are vector diagrams showing a relationship among each phase voltage, each phase current, and an interphase voltage when a distribution line is abnormal.

FIG. 5 is an explanatory diagram of each signal when an abnormality occurs in the embodiment.

[Explanation of symbols]

 Reference Signs List 2 distribution line 3 master station 4 transmission line 7 slave station 8 first communication device 9 second arithmetic device 10 second communication device 11 interphase voltage measurement device 12 zero-phase current measurement device 13 phase difference measurement device 16 phase current measurement Device 17 Phase determination device 18 First arithmetic device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01R 31/08 H02H 3/26-3/30 H02H 3/32-3/52 H02H 7/26

Claims (1)

(57) [Claims] 1. A distribution line automation system having a master station communicating with a plurality of slave stations provided on a distribution line via a transmission line, wherein the slave station measures an arbitrary phase current of the distribution line. A device, a zero-phase current measuring device for measuring a zero-phase current of the distribution line, an inter-phase voltage measuring device for measuring an arbitrary inter-phase voltage of the distribution line, and a phase difference for measuring a phase difference between the zero-phase current and the inter-phase voltage A measuring device, a phase determination device that determines whether the phase of the inter-phase voltage is normal or inverted from the phase difference between the inter-phase voltage and the phase current, and the phase difference measurement when the phase of the inter-phase voltage is reversed. A first computing device for inverting the phase difference measured by the device, and a first communication device for communicating with the master station, wherein the master station communicates with the slave station. A communication device and a second communication device collect from a plurality of the slave stations. Fault section detection device of the distribution line and a second arithmetic device determines fault section by the phase difference information.