JPS6194519A - Method of detecting ground point of distribution line - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) This invention injects a search signal from a search signal injection device into a distribution line so as to detect a ground fault point occurring in the distribution line. ,
Relates to a method of displaying a ground fault from the injection point of a search signal injection device to a distribution line to a ground fault point using an appropriate number of display devices v5, and easily detecting the ground fault point by primary patrol from the search signal injection side. It is something.

(Prior art) Conventionally, when a ground fault occurs in a distribution line, substation circuit breakers have been installed from the viewpoints of early detection of faulty sections, separation of faulty sections, and early transmission of power to healthy sections. Next, the substation circuit breaker is reclosed, and the section switches on the power supply side are sequentially turned on to transfer the power to the healthy section, and when the substation reaches the faulty section, the substation is shut off again. Ru. Then, when the circuit breaker of the substation is closed again, the section vn PJl device that separates the ground fault fault section is locked in the open state and the ground fault fault section is closed [only for 3 minutes]. By retransmitting power only to healthy sections, we are searching for sections with ground faults. Once the C1 ground fault fault area has been searched, the ground fault point can be detected by repeatedly measuring the insulation resistance of the related power distribution equipment installed on each utility pole in the fault area.
I was cumming.

(Problems to be Solved by the Invention) As mentioned above, in the past, after the ground fault fault section was identified, the insulation resistance of the related power distribution equipment installed on utility poles, etc. existing in the ground fault fault section was sequentially determined for each utility pole. There was a work problem in that it took a lot of time to perform measurements.
There was a drawback that it took a long time to detect the ground fault point.

Structure of the Invention (c) Means for Solving Problems) This invention has been made to solve the above-mentioned problems.)C1 The method for detecting a ground fault point in a distribution line according to the present invention is to connect a distribution line to a sectional switch. When a ground fault occurs between the sectional switches, the sectional switches at both ends of the section where the ground fault has occurred are opened by re-closing the circuit at the substation circuit breaker. In the distribution system that detects A display device is connected to a search signal injection device, which always displays a normal display in the section, and when the search signal is detected, changes from a normal display to a ground fault display based on the search signal. In addition to injecting No. 5 into the distribution line from the search signal injection device, the search signal flowing through the distribution line and the ground fault point causes the display device to display a ground fault. This is a summary.

(Function) According to the above configuration, when a ground fault occurs in the section of the line and Q divided by the sectional switch, the substation circuit breaker is cut off. Then, the section switch opens after a delay opening time. The amount of delay ti' from when the substation circuit breaker breaks to when the section switch opens! , the search signal injection device uses the search signal injection device to search (no. 5 is injected into each phase. Then, the search signal flows through the distribution line and the ground fault point. As a result, the search signal injection device The display device existing between the points changes from the normal display to the ground fault display based on Search No. 13.

As a result, if a primary tour is performed from the injection point side of the search signal, the final point where the ground fault indication is performed becomes the ground fault point.

(Embodiment VA) Hereinafter, a preferred embodiment embodying the present invention will be described with reference to FIGS. 1 and 8.

1 is the power transmission line, turtle is the substation circuit breaker (hereinafter referred to as CB)
3 is a distribution line connected to the transmission line 1 & C via the CB 2, and each phase is connected to 3a, 3a, and 3a as shown in FIG.
3b, and 3Cr. 4 is a zero-phase current transformer (hereinafter referred to as ZCT) of the substation installed immediately in front of the C132.
, 5 is a grounding transformer (hereinafter referred to as GPT) installed in the power transmission line 1, which detects a single-line fault occurring in the distribution line 3 by means of both 4.5 and connects the directional ground fault relay 6. The C132/, i +- lip is activated to disconnect the power distribution line 3 from the power transmission line 1.

A large number of section switches SS are arranged on the distribution line 3,
A large number of sections △11 (n = 1.
2.3...) are classified.

This section switch SS is a conventionally known section switch,
As shown in Figure 8, if a ground fault occurs within a certain section (
At T1), substation CB2 selects and disconnects the faulty line at T2.
(time), when the fault line becomes non-voltage, each section switch SS opens the circuit after a delay opening time Z (at time T6). Next, when voltage is applied by re-closing CB2 (at T3), the first section switch SS adjacent to CB2 closes after X hours (at T7), and the load-side section switches When a voltage is applied to SS, each circuit closes to 1 after X hours.

In this way, the power is sequentially turned on from the section switch SS on the power supply side to retransmit power to the healthy section, and when the section reaches the ground fault section, the substation CB2 is shut off again (at time T4). Then, CB2 of the substation is closed once again (at time T5), and the segment switch SS that separates the ground fault fault section is locked in the open state, so that only the ground fault enemy camp section is segmented. It has become.

7 is the nearest r゛11 of ZCT4 to the distribution line 3 of each phase.
The search signal injection device is connected to the front side, and has one and two positions (see Fig. 1). This search signal injection device 7 inputs a trip signal from CB2 when substation CB2 is cut off (at T2), and based on the trip signal, from the time when 082 is cut off (at T2), the first l section switch S.S.
When the circuit opens (T6 time>lJ:, the delay opening time 7 is used to search (No. 3 is injected all at once in the phase).

J3, this search signal is injected into the first section switch S.
It is set to end before S opens (
11''1 from 8:00 to 9:00 as shown in FIG. 8).The driving power source of this search signal injection device 7'' is provided by a transformer Tr connected to the power source side of CB2.

Referring to FIG. 3, 1-1 is a plurality of display devices installed in each phase in each section An of the distribution line 3, and are spaced apart from each other by a predetermined distance.

This display device 1-1 will be explained.

8 is a current transformer connected to the distribution line 3; 9 is a ground fault 1sen υ connected to the current transformer 8; when a search signal current of a certain level or higher flows through the distribution line 3; The transform signal output from the current transformer 8 is detected and a ground fault detection signal is output.

Reference numeral 10 indicates the entire display section which is not connected to the ground fault detection sensor 9. In this display section 10, a plurality of magnetic reversal display devices are arranged adjacent to each other in a plurality of p.177 as shown in FIGS. 6 and 7.

To explain this magnetic reversal display in detail with reference to FIGS. 4 and 5, a disk 11 whose both ends are magnetized in In and S (ru) is rotatably supported around a rotation shaft 12. In addition, the round bar-shaped stator 13 has a magnetic pole portion 1321 corresponding to the S pole of the disk 11 and N tU of the disk 11.
It is preferable that the stator 13 is formed of a material having a small holding force.

Between the two magnetic pole portions 13a and L3b, there are rotating magnets (stop portions 13a,
The coil 14 is wound so that the coil 13b is magnetized with the same polarity as the width of the disk 11 in the state shown in FIG.

The front surface 11a and the back surface 11b of the disk 11 are marked with completely different colors (in this embodiment, the front surface 1'l F, l
is black and the back side 11b is red) is displayed, and the display device]-
It is visible from below 1.

When the display section 10 receives the ground fault detection signal from the ground fault detection sensor 9, a drive current flows through the coil 14, and as shown in FIG.
, the magnetic pole part 13b is magnetized to the N pole, and the N pole of the disk 11 is magnetized to the mh part 13a (S pole), and the S pole is magnetized to the magnetic pole part 1.
3b (N pole), and a label labeled fJ is displayed on the back surface 11b of the disk 11 externally. Moreover, the stator 13 of this display section 10
is provided with a coil (not shown) that is wound in the opposite direction to the coil 14, and this coil (not shown) is provided with a coil (not shown) that is wound in a direction opposite to that of the coil 14. '117: When a current of υ flows, the magnetic pole parts 13a, 13bh in the ground fault display state return to the polarity of the textile display, and as a result, the disk 11 returns to reverse and returns to normal display (Figs. 4 and 6). reference).

Reference numeral 15, not shown in FIG. 3, is a timer connected to the display section 10.
After a predetermined period of time (for example, after 3 to 4 hours), a return drive current is applied to the above-mentioned illumination (not shown), and the display section 10 is returned from the ground fault display to the normal display.

Note that 16 is a display unit 10 connected to the current transformer 8.
．． This is a driving power source for the ground fault detection sensor +19 and the timer 15.

Further, this display device 1-1 has the ability to also serve as a short circuit display. That is, 17 is the current transformer 8 of 1111
A short circuit detection sensor connected to the power distribution line 3, when a constant short circuit current equal to or higher than the bell flows through the distribution line 3, outputs a transformation signal from the current transformer 8 and displays it on the display section 10. A short circuit detection signal is output, and a short circuit is displayed on the display section 10 based on the zero circuit detection signal as in the case of ground fault detection.

Note that this display section 10 is activated in the same manner as in the case of the ground fault display by applying a return drive current from the tie 715 after a predetermined period of time (3 to 4 hours) after the state of displaying the J-bean paste. The display section 10 is then returned from the short-circuit display to the F9 display.

Note that AS, not shown in FIG. 2, is a normally closed switch.

Next, the operation of the system configured as described above will be explained.

Now, as shown in Figure 2, it is assumed that a single-line ground fault has occurred at point m of phase a in section △3 of distribution line 3 (1j).
"1 o'clock>. For convenience of explanation, only the a phase 3a of the power distribution system 13 is illustrated in FIG. 2.

Then, ZCT4 of the substation outputs zero-sequence current, GPl;) outputs zero-sequence voltage as a ground fault signal, and C through relay 6.
A trip signal is sent to B2, and substation CB2 is opened (at H2).

The search signal injection device 7 inputs the trip signal from CB2, and based on the trip signal, from the time when C132 is cut off (at H2) to the time when the section switch SS is opened (at H2).
The search signal current is applied to each phase of the distribution line 3a, 3b using the delay opening time Z until 6 o'clock).

Inject each into 3C (from 18:00 to 19:00 according to Figure 8)
time).

Then, the search signal injection device 7. A circulating current flows in a closed loop path passing through the distribution line 3a, the ground fault point m, and the search signal injection device 7, and as a result, the circuit is placed between the injection point of the search signal injection device 7 and the ground fault point T. Display device, namely A1
118 and the display device H1 in the A2 section, and the display devices H2 and H3 in the A3 section.

That is, when a search signal current of a certain level or more flows through the distribution line 3a', the display device Hl of the A1 section and A2 section
etc. and the display device in the A3 section) -12, the current transformer 8 of H3 outputs a transformation signal based on the search No. 13 current,
The ground fault detection pin 9 outputs a ground fault detection signal in response to the transformation No. 13. Then, the display unit 10 inputs the ground fault detection signal and displays the ground fault detection signal based on the ground fault detection signal.
A drive current flows through.

Then, the magnetic pole part 1 is changed from the state shown in FIG. 4 to the state shown in FIG.
3a becomes the S pole, (the xylem 13b is magnetized as the N pole,)'
The iskco 1 reversely rotates so that its N pole faces the magnetic pole part 13a (S(Φ)) and its S pole faces the magnetic pole part 13b (N pole).
A color sign attached to the ground fault is displayed externally to indicate a ground fault (see Figure 7).

-j;' Regarding the o and c phases, a closed loop including the ground capacitance of the distribution line 3 instead of the ground fault point 10 is formed, but the impedance of this loop is high, the flowing search signal current level is low, and other Two-phase 3b.

Display device 1, which was purchased Oe by 3C, remains in normal display mode.

In addition, even if the display device is installed on the a phase, it can be searched (3
, the ground fault f-IT occurs because the Q current does not reach a certain level or higher.
From I (1), the display device H4 etc. provided on the front side remain in normal display mode.

This search signal injection device 7 displays a ground fault on the display device at the ground fault point mJ.
The current is injected before the sectional switch SS opens (1℃)
11”■).

After the search img injection device 7 injects the search signal current as described above (after 7 hours have passed since the substation CB2 was cut off), the section switch SS opens the circuit (H
6 o'clock). Then, when voltage is applied by re-closing CB2 (H3 hour), the first section switch SS adjacent to substation CB2 closes after X hours (77 hours), and then the load side Similarly, when voltage is applied to the section switch SS,
After a certain period of time, the circuit is opened in the same way.

In this way, the power is sequentially turned on from the closed circuit SS for 8 minutes on the power supply side, and power is retransmitted to the healthy section, and when it reaches the ground fault section, the substation CB2 is disconnected again (H4:00). and,
When both circuit breakers 2 of the substation are closed (at H5), the section switch SS that separates the ground fault fault section 3 is locked in the open state, and only the ground fault fault section A3 is isolated.
Power will be retransmitted only to healthy sections.

As mentioned above, the ground fault section A3 can be detected by locking the sectional switch SS in the open state, so the next step is to carry out work (1) from the power supply side towards the load side in that ground fault section. set off.

Then, sequentially search for the date of the display device in the ground fault display state (
), there is a ground fault point m between the point where the display device H3 displaying a ground fault, which is one place before the display device H4 not displaying a ground fault, and the point where the display devices l to 14 are arranged. I can tell the difference.

In addition, in searching for the ground fault point, at the branch point α, the display device 115 provided on the branch line on one load side is compared with the display H3 provided on the branch line on the other load side. All you have to do is proceed along the branch line on the side where the display device H is displaying the ground fault indication.

The display device 11 that has displayed the ground fault indication as shown in J5 and +W7 will restart the return drive current after a predetermined time (for example, 3 to 4 hours) after the timer 15 indicates that the display unit 10 indicates the ground fault. is applied to the coil (not shown), and as a result, the display section 10 returns from the ground fault display to the normal display.

Note that when CB2 is shut off again (at time T4), the search signal injector 7 again uses the delayed opening time 7 of the sectional switch SS to inject the search signal current, but the display that has already given a ground fault indication The device 1 continues to display the ground fault as it is, and the display device H, which is displaying the normal state, displays the normal state for the same reason as described above.

Next, we will explain the case of a short circuit accident.

When a short circuit current of a certain level or more flows through the distribution line 3, the current transformer 8 outputs a transformation signal based on the short circuit current,
The short/circuit detection sensor 17 outputs a short circuit detection signal to the display section 10 in response to the metamorphic 1 symbol. Then, the same short circuit detection signal; Then, after a predetermined period of time (3-=/!1+-'r I?Vl i) after entering the short-circuit display state, this display section 10 switches back to the ground by applying a recovery drive current from the timer 15. The short circuit display returns to the normal display in the same way as the short circuit display.

In addition, in this embodiment, since a magnetic reversal display device is used for the display section 10, the display device 1 can have a simple configuration.
Moreover, it can be manufactured cheaply, and even when a large number of them are arranged in each section, the entire system has the advantage of not requiring any stress.

Furthermore, in this embodiment, even if substation CB2 recloses and retransmission is successful, the search signal injection device 7 injects the search signal current after CB2 is first cut off, so retransmission, which was previously impossible, is possible. There is an advantage that the ground fault position can be easily discovered in case of success.

Next, a second embodiment will be described with reference to FIG.

In this embodiment, among the configurations of the previous embodiments, only the growth of the display device 1-1 is different. That is, the display device H includes a current transformer 8 attached to each phase distribution line, a resistor R connected between both terminals of the current transformer 8, and a light emitting diode L connected between both terminals of the current transformer 8.
A search 1h detecting section 18 is provided, which includes a series circuit with ED1 and a light emitting diode LED2 connected in parallel to the circumferential light diode LEDI and arranged in the opposite direction to the light emitting diode LFD1.

When the current transformer 8 inputs the search signal current, the search signal detection unit 18 causes the light emitting diodes LED1 and LED2 to emit light based on the transformed current output from the current transformer 8. There is.

The light emitting diode LE of the search signal detection unit 18 in each phase
D1. An optical lens 19 is disposed corresponding to the LED 2, and the sensor 19 connects the light-emitting diode to a light intensity level comparison circuit 21 via an optical fiber 20, using the vehicle ahead of the light emitting diode as a light source.
Output to. The same light level comparison circuit 21 compares the three phases when the optical signals of the light emitting diodes LEO1 and LED2 detected by the optical sensor 19 of each phase are equal to or higher than a certain level, and when the three phases are equal or approximately equal. The drive current is not output during this period. On the other hand, when any one phase has a larger light level than the other two phases, a drive current of more than I is output to specify that one phase.

The display unit 22 is connected to the light level comparison circuit 21,
The power supply circuit 23 of the "display device 1" is a current transformer installed in one phase so that the drive current for specifying the -phase is 4, and the -phase is specified and displayed. Vessel C
T, photon level comparison circuit 21 and display section 22
The drive current is supplied to the

In this embodiment "c", when the current transformer 8 inputs the search signal current flowing to the ground fault phase, a transformed current is output from the current transformer ε3, and based on the transformed current, the light emitting diodes LED1 and LED2 are At the end of 1J, the optical signal output from the optical sensor 19 is input to the light level comparison circuit 21 via the optical fiber 20, and the light level comparison circuit 21 compares the light manually inputted from each phase (with a constant level). In the above case, the three phases are compared, and if any phase has a higher level of optical signal g than the other two phases, a drive current is output to identify that one phase.

Then, the display section 22 manually inputs a drive current for specifying the negative phase, and specifies and displays that one phase based on the drive current.

In this embodiment, a display device H is provided for each phase.
Since the display is performed on the common display unit 21, the display device 1-1 can have a simple configuration.

J5, this invention is not limited to the above-described embodiment; for example, in the first embodiment, the search signal injection device 7 is
The search signal injection device 7 may be injected only when CB 2 is cut off for the first time.

Further, in the first embodiment, the display device 1 is configured to return to display using the timer 15, but instead, when retransmission is successful, the display device is configured to return to display using a current at a frequency that flows after retransmission. It is also possible to configure H. In this case, a ground fault display will be made only in the case of a permanent fault among ground faults.

Effects of the Invention As detailed above, this invention is effective against ground faults. Since the search No. 11 current is injected from the search signal injector between the FZs, there is no need to newly install numerous and expensive ZCTs and VODs to detect ground faults. This method has the advantage of being able to detect a ground fault point at a very low cost.It also has the great advantage of being able to identify a ground fault phase.

Furthermore, since it is only necessary to provide as many search signal injection devices as there are substations CB, the number of search signal injection devices can be greatly reduced.Furthermore, search signals can be automatically injected, ensuring 11! ! It is possible to display contact information.

Furthermore, the driving power source of the search signal injection device is the electric power source of the substation.
Since it can be used for iGI history, the power of the injected current can be increased, which is a truly convenient configuration.

In addition, since the search (a display device operated by the No. 3 current is installed), two workers can detect ground faults without imitating the time it takes to make a primary tour from the power supply side to the load side in the ground fault fault section.
There is a practical human river fish whose lj can be easily identified.

In this case, the display devices, which need to be installed in large numbers at various locations on the distribution line, do not need a function to send information about their display status to the relay point of the substation claw '1, and Adopting a convenient configuration that does not require consideration of insulation, the detection method of the present invention becomes extremely simple and simple.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a distribution line system diagram provided with a search signal injection device, FIG. 2 is a distribution line diagram for explaining the operation, and FIG. 3 is an electric circuit of a display device. 4 is a perspective view of the magnetic reversal display device, FIG. 5 is an explanatory diagram showing the operation of the magnetic reversal display device, FIG. 6 is a bottom view of the display unit in the normal display state, and FIG. 7 is a FIG. 8 is a bottom view of the display unit in a ground fault display (short circuit display) state, FIG. 8 is a time chart, and FIG. 9 is an electric circuit diagram of the display device of the second embodiment. DESCRIPTION OF SYMBOLS 1... Power transmission line, 2... Breaker (CB), 3... Distribution line, 4... Zero-phase current transformer (ZCT), 5... Grounding transformer (GPT), 6...・・Outside direction I8 relay, 7・・
- Search signal injection device, 8... Current transformer, 9... Ground fault detection sensor, 10... Display unit, 17... Drive? R
source, 1-1...display device, SS...section switch. Patent applicant: Takamatsu Electric Manufacturing Co., Ltd.
Person Patent Attorney On 1) 1 (9th Sen Figure 6 Figure 7 Figure 8 Self-sho Procedure Valley 1i-Qi Commissioner of the Patent Office Manabu Shiga 2, Title of Invention Method for Detecting Ground Fault Points in Distribution Lines 3) Relationship with the case of the person making the amendment: Patent applicant Address: 1-1 Kobari, Inuyama Elementary School, Aichi Prefecture Name:
Takamatsu Electric Manufacturing Co., Ltd. (Name) Representative
Shigetsugu Takaoka 4, agent (1 location rEL, 2 Hatazume-cho, Gifu City, 500)
0582>65-1810 (Representative) 6, Supplement i [Of the drawings, Figure 1 has been corrected as shown in the attached sheet. D-41 Sales: 'Yama 1F, '+'Tj (pu)j
()February 14, 1985 1. Table of events Small special revision application No. 214867 of 1988 2. Name of invention Method for detecting ground fault point in power distribution line 3. 1 Which relationship: Rii'l applicant address
1 Kamikobari, Inuyama Elementary School, Sassichi Station Name Stock Trial Takamatsu Electric Manufacturing Co., Ltd. (Name f:+1) Representative Takaoka
Shigetsugube 4, Daikokuto () 〒500 2, Kikushi Kobatazume-cho lTL <
0582>65-1810 (representative) O, the elephant of mountain 11

Claims (1)

[Claims] 1. The distribution line is divided by section switches, and when a ground fault occurs between the section switches, reclosing is repeated at the substation circuit breaker, thereby dividing the section where the ground fault has occurred. In a power distribution system in which a ground fault section is detected by opening the sectional switches at both ends, each phase on the load side of the substation circuit breaker has a delay from when the substation breaker breaks to when the sectional switch opens. A search signal injection device that injects a search signal using the open time is coupled, and the section is always displayed as a normal display, and when the search signal is detected, the normal display is changed to a ground fault display based on the search signal. A plurality of display devices are arranged to perform
A method for detecting a ground fault in a power distribution line, characterized in that the display device displays a ground fault.