JPH0756500B2 - Distribution line failure section determination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used for surely and early detection of a failure section such as a short circuit, ground fault, or disconnection of a distribution line, and for early recovery of a failure occurrence point. It relates to the device.

[Conventional technology]

FIGS. 3 (a) and 3 (b) relate to a conventional faulty section determination device for a distribution line shown in, for example, "Protective Relay Handbook" P393-P394 published by Ohmsha Co., Ltd., which is called a progressive feed timed type.

In the figure, (5) is a distribution substation busbar, (6) is a distribution line, (CB1) is a circuit breaker, (SS1) (SS2) (SS3) is a section switch, and (TR1) (TR2) (TR3) Is a voltage transformer, (C
1) (C2) and (C3) are classification switch control devices.

Next, the operation will be described. The fault occurring in the distribution line (6) is once removed by opening the circuit breaker (CB1) by the operation of a protective relay (not shown in the figure) arranged at the position of the circuit breaker (CB1). After that, the circuit breaker (CB1) is turned on by the operation of the reclosing relay not shown in the figure,
The area between (CB1) and (SS1) is charged. The controller (C1) turns on the classification switch (SS1) if it receives power continuously for X seconds after receiving the power.
If the power transmission is continued for Y seconds after the power is turned on, the power supply circuit of itself is in a normal state (triggered with no voltage and can be turned on X seconds after receiving the power).
However, if a power failure occurs again within Y seconds, the closing mechanism will be locked when the next power is received and power will not be transmitted to the next section.

Since the segment switches (SS2) and (SS3) perform the same operation below, the segment switches are sequentially turned on for the first time until the faulty section, and a second fault occurs when the faulty section is charged (CB
The second trip of 1) is performed and the circuit is closed again. After this 2
The division switches are turned on sequentially for the second time, and since the closing switches before the faulty section are closed, they are not turned on.

In this way, it becomes possible to automatically restore only the power transmission possible section.

[Problems to be solved by the invention]

Since the conventional failure section determination device is configured as described above, it is necessary to generate a second artificial failure in addition to the first failure occurrence in order to discover the failure section, which has an effect on the entire system. Not only is it large, but since it is charged again at the point of failure, it could pose a safety problem such as a danger to humans and a fire.

In addition, there was a drawback that the restart of power transmission to the power transmission section was delayed.

The present invention has been made to solve the above-mentioned problems, and in order to reliably determine the failure section at the time of the first failure occurrence, the charging of the failure section is locked and the power transmission is resumed early only in the transmittable portion. It is also an object of the present invention to provide a distribution line failure section determination device that enables early restoration of a failure section.

[Means for solving problems]

The distribution line failure section determination device according to the present invention detects the magnitude of the passing current of each distribution switch of the distribution line, a device for detecting the phase relationship with respect to the voltage, and the passing current information including the phase relationship with respect to this voltage, or mutually. Equipped with a device that determines the failure section by comparing the transmitted current information of each section switch that has been transmitted, and the section with the largest change in the passing current information distribution of each section switch is the failure section. It is a judgment.

[Action]

The distribution line failure section determination device according to the present invention utilizes the fact that the distribution of passing current information including the phase relationship with respect to the voltage changes the largest at the section switches at both ends of the failure point. As the passing current information including, use the vector amount (magnitude and phase) of the passing current, the direction determination result for the voltage of the passing current (in-phase direction or opposite phase direction), or the direction determination result for the magnitude and voltage of the passing current. Thus, effective failure section determination can be performed.

〔Example〕

An embodiment of the present invention will be described below. In FIG. 1, (1) is a power source, (2) is a distribution substation, (3) is a transformer, (4) is a grounding transformer, (5) is a busbar, (6) is a distribution line, (7). Is a communication line, (8) is a master station, (9) is a determination device, (SS1) (SS2) (SS3) are section switches, (CT1) (CT
2) (CT3) is a current transformer, (TR1) (TR2) (TR3) is a voltage transformer, (C1) (C2) (C3) is a section switch controller,
(T0) (T1) (T2) (T3) are transmission terminals.

The current information detected by the current transformers (CT1) (CT2) (CT3) is processed and operated by the divisional switch controller, and the information regarding the magnitude and the direction or phase relationship with respect to the voltage is extracted. Information about this current is sent to the master station determination device (9) via the transmission terminals (T0) (T1) (T2) (T3). This master station determination device compares the current information of each section switch and determines the failure section. Depending on the result of this judgment, an open signal is sent to the segment switch adjacent to the faulty section to disconnect it from the distribution line, or a closing lock signal is sent to prevent the closing after receiving power, and power is re-received only in the necessary section. If possible. In addition, the parent station will be able to perform recovery activities early by displaying the faulty section.

The magnitude of the fault current, the phase with respect to the voltage, and the direction of the fault current with respect to the voltage are described in, for example, the Institute of Electrical Engineers, University of Electrical Engineers, "Protective Relay Engineering" p112, (July 20, 1981).
It can be calculated using existing technology such as the calculation principle of the digital relay described in Japanese, first edition).

That is, the instantaneous values of the passing current and voltage of each section switch are taken into each section switch controller, sampled at an electrical angle of 30 °, and the following data is converted from the analog quantity to the digital quantity. Calculate.

X ² ＝ x ₀ ² ＋ x _-3 ²・ ・ ・ Equation 4 XYcos θ ＝ x ₀ y ₀ ＋ x _-3 y _-3・ ・ ・ Equation 5 XYsin θ ＝ x ₀ y _-3 −x _-3 y ₀・..Formula (6) Where: X: Current absolute value calculation result Y: Voltage absolute value calculation result θ: Current voltage phase calculation result x ₀ ; Current sampling current value x _-m ; m Sampling current value before sampling {For example
x _-3 ; Sampling current value before 3 sampling (90 ° at 30 ° sampling interval)} y ₀ ; Current sampling voltage value y _-m ; m Sampling voltage value before sampling {eg
y _-3 ; sampling voltage value before 3 samplings (90 ° at 30 ° sampling interval)}.

From the above equations (1) to (4), the absolute value of the current is (7)
The phase of the current with respect to the voltage can be obtained by the equation.

Further, by determining whether the equation (5) or (6) is positive or negative, the direction determination result for the current voltage can be obtained.

Next, the operation of the master station determination device will be described with reference to FIG. Second
Figure (a) is an example of a system diagram having two distribution lines.
(CB1) (CB2) is a circuit breaker, (SS11) (SS12) (SS13)
(SS21) (SS22) (SS23) are sectional switches, (C11) (C1
2) (C13) (C21) (C22) (C23) is the amount of floating in each section of the distribution line, (I11) (I12) (I13) (I21) (I22) (I23) is the passing current of each section switch is there.

Now consider failure (F1) (F2) (F3) in each section of Line 2.

FIG. 2 (b) shows an example of current distribution at the time of short circuit failure. When the F1 point short circuit fault (SS21), the passing current (I21) is a large short circuit current determined by the impedance of the power source behind. On the other hand, a relatively small current flows from (SS22), (SS23), etc. to the failure point due to the load of the rotating machine. Therefore (F1)
In case of point failure, there is a big difference between (I21) and (I22),
The difference between (I22) and (I23) is small.

Similarly, in the case of (F2) and (F3) failures, there is a large difference between the passing currents of the sectional switches adjacent to the failure point, and other differences are small.

FIG. 2 (c) is a vector diagram of the passing currents of the respective switchgear with respect to the voltage at the time of the F1 point short-circuit fault (in the figure, the phase voltage Va before the accident of the phase A). The magnitude relationship is as described in FIG. 2 (b), but the phase relationship is (I21) is the phase determined by the back impedance and the fault point resistance. Also (I22),
(I23) has a phase relationship such that the load of the rotating machine flows backward.

Therefore, when comparing the passing currents of each section switch as a vector quantity, there is a big difference between (I21) and (I22).
It becomes clearer that the difference between 2) and (I23) becomes smaller than when comparing only the sizes.

Fig. 2 (d) shows the distribution of these judgment results at the time of F1 point short-circuit fault after discriminating the in-phase direction as the forward fault and the opposite phase direction as the backward fault in Fig. 2 (c). is there. In this case, the direction is reversed between (I21) and (I22), and it can be determined that there is a failure in the section between these. This method has a feature that the transmission device can be simplified because it is not necessary to transmit the magnitude or phase amount and only the direction determination result needs to be transmitted.

FIG. 2 (e) is a combination of the magnitude of the current and the same direction determination result as in the case of FIG. 2 (d).
The difference becomes clearer and the judgment becomes more reliable than simply judging the size.

FIG. 2 (f) is a current distribution when a ground fault occurs. At F1 point failure (SS21), passing current (I21) is Line 1 stray capacitance (C11)
A relatively large sum of the charging currents of (C12) and (C13), the resistor current busbar (5) of the grounding transformer (4) and the transformation current up to the fault point passes. On the other hand, charging currents such as stray capacitances (C22) and (C23) flow through (SS22) and (SS23), and relatively small current passes through them. Therefore, in case of (F1) point failure (I21)
There is a large difference between and (I22), and the difference between (I22) and (I23) is small. Similarly, in the case of (F2) and (F3) failures, there is a large difference between the passing currents of the sectional switches adjacent to the failure point, and other differences are small.

Also, in the case of an incomplete ground fault with resistance at the fault point, the magnitude of the fault current becomes smaller, but the difference in the passing currents of the segment switches adjacent to the fault point remains the same.

Figure 2 (g) is the current vector distribution for the system zero-phase voltage V ₀ at (F1) ground fault, (I21) is the back charging current,
The phase relationship is determined by the grounding transformer resistor current and the fault point resistance. Also, (I22) (I23) is the section stray capacitance (C21) (C22)
The phase relationship is determined by the charging current of. A forward failure and a backward failure are distinguished by a direction determination straight line that can determine the current directions.

FIG. 2 (h) is a direction distribution of the current in the case of (F1) ground fault, and FIG. 2 (i) is a diagram showing a distribution in which the magnitude and the direction of the current in the case of (F1) the ground fault are combined. Figure 2 (g)
For (h) and (i), the same judgment as in the case of the short-circuit fault in FIGS. 2 (c), (d) and (e) is performed.

Although not shown, it is possible to determine the disconnection section by detecting a rapid change in the distribution of the load current or a rapid change in the reverse phase or zero-phase current distribution even when the distribution line has a disconnection failure. .

As described above, the distribution line failure section determination apparatus according to the present invention focuses on the distribution of the magnitude of the current and the direction or phase relationship with respect to the voltage, compares the passing currents of the respective section switches, and detects a rapid change in the distribution. The failure section is determined by

In the above-mentioned embodiment, the communication line is used as the transmission means, but any means can be used as long as the current information can be transmitted.

Further, in the above-mentioned embodiment, an example in which the master station is provided and the failure section determination is performed at one location of the master station is shown. However, a determination device is provided in each division switch to make a determination by comparing the current information with the adjacent section. Good.

Further, a means for displaying the current distribution on a display device such as a CRT and for confirming it with human eyes may be added.

〔The invention's effect〕

As described above, according to the present invention, the distribution line failure section determination device includes a device that detects the magnitude of the passing current of each distribution switch of the distribution line, a device that detects the phase relationship to the voltage, and a passing current that includes the phase relationship to this voltage. Equipped with a device that transmits information to each other or a specific place and a device that compares the transmitted passing current information of each section switch to determine a failure section, and the change in the passing current information distribution of each section switch is the largest Since it is configured to judge the section as a failure section, it is possible to make a reliable judgment when a failure occurs, and the influence of forced transmission on the system is small,
It is possible to provide a device that has high safety against a human body, a fire, and the like, and can re-transmit power in a required section quickly.

As the passing current information including the phase relationship with respect to the voltage,
By transmitting the passing current vector amount (magnitude and phase) and determining the failure section, the change in distribution is larger in the failure section than in the case of only the magnitude of the passing current, and more reliable judgment can be performed. Further, by transmitting the direction determination result (in-phase direction or opposite-phase direction) with respect to the voltage of the passing current and determining the failure section, it is possible to reduce the amount of transmission as compared with the case of the magnitude of the passing current. Further, by transmitting the direction determination result for the magnitude of the passing current and the voltage and determining the faulty section, the difference becomes clear with a slight increase in the transmission amount compared to the case where only the magnitude is determined, and the determination becomes more reliable. .

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of a distribution line failure section determination device according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the operation of an embodiment of the present invention, and FIG. 3 is a conventional distribution line failure section. It is a figure which shows the principle of a determination apparatus. In the figure, (1) is a power source, (2) is a distribution substation,
(3) is a transformer, (4) is a grounding transformer, (5) is a busbar,
(6) is a power distribution station, (7) is a communication line, and (8) is a master station.
The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (4)

[Claims] 1. A device for detecting a magnitude of a passing current of each section switch of a distribution line and a phase relation with respect to a voltage, a device for transmitting passing current information including a phase relation with respect to the voltage to each other or a specific place, and transmission. A distribution line characterized by comprising a device for comparing the passing current information of each of the divided switches and determining a failure section, and determining the section in which the change in the passing current information distribution of each of the divided switches is the largest as the failure section. Failure zone determination device. 2. The distribution line fault section determination device according to claim 1, wherein the phase relationship between the magnitude of the passing current and the voltage of each section switch is transmitted and determined as a vector quantity. . 3. The device according to claim 1, wherein the direction is discriminated by whether or not it is within a specific phase difference with respect to the voltage of the passing current of each section switch, and the direction discrimination result is transmitted and judged. A distribution line failure section determination device characterized by the above. 4. The method according to claim 1, wherein the direction determination result is transmitted depending on whether or not the magnitude of the passing current of each section switch is within a specific phase difference with respect to the voltage.
A distribution line failure section determination device characterized by making a determination.