JPS63124720A - Failure locator for 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] [Industrial Application Field] The present invention relates to a distribution line connected to a distribution line breaker in a substation, which is connected to a distribution line breaker, and which is provided in correspondence with a section switch that divides a distribution line into multiple sections. Regarding accident investigation equipment.

[Prior art J: An accident investigation system in which a distribution line connected to a distribution line breaker in a substation is divided into multiple sections using section switches, and each section switch is provided in response to an accident on the distribution line. In power distribution systems in which sectional switches are controlled by devices, a timed sequential system as shown in FIG. 5 is generally adopted.

In other words, this time-limited sequential transmission method
Continuously energized section switch Ass (ASSI,
ASS2. ASS3. ......) to distribute power la
L is divided into multiple sections and each section switch A
In correspondence with the SS, a time-limited progressive accident investigation device cR having a configuration as shown in Fig. 6 is provided, and input to this time-limited progressive accident investigation device CR is inputted from the power supply side line at the dividing point via the power transformer Tr. The sectional switch is controlled depending on the presence or absence of the applied voltage.

As shown in FIG. 6, the time-limited progressive accident investigation device starts counting when voltage is applied from the power transformer Tr, and when the closing time X has elapsed, the closing timer T1. In response to the operation of this turn-on timer T1, the power transformer ``rrt''
The closing relay Ry closes the output contact Rya provided in the closing circuit that excites the section switch ASS as a power source, and when the closing timer T1 operates, the output signal is memorized and the output contact Kb starts the closing timer T1. It is composed of a memory relay that locks the circuit and a detection timer T2 that is set to ON.

Here, to describe the principle of fault section detection classification in the distribution system configured as described above, if a distribution line fault occurs in, for example, section When the wire circuit breaker CB performs the circuit breaker operation, each section switch ASS of the line opens all at once.

After a certain period of time has elapsed, the distribution line breaker CB of the substation P recloses, and when voltage appears in the distribution line section I, the accident investigation device CR corresponding to the division switch As51 at that division point is activated as shown in Fig. 7. The operation shown in (a) is performed. That is, when a voltage appears in the interval (3), that voltage is applied from the power transformer Tr to the turn-on timer T1 and starts counting. Then, when the closing time limit X has elapsed, the closing timer T1 operates, and the output contact Ry of the closing relay Ry responds to the output of the closing timer T1.
The closing circuit excites the closing circuit of the section switch ASSI, and the section switch ASSI is closed. At the same time, the detection timer T2 starts counting and the memory relay K stores the operation output of the closing timer T1, but since there is no accident in section ■, there is no power outage while the detection timer T2 is counting for a certain period of time. . Therefore, the detection time limit T
2 operates after a certain period of time has elapsed to reset the memory relay K, so the starting circuit of the closing timer T1 is not locked.

Next, when voltage appears in section ■ by turning on section switch ASSI, accident investigation device C corresponding to section switch ASS2
R operates as shown in FIG. 7(b). That is, when a voltage appears in the interval (3), that voltage is applied from the R source transformer Tr to the closing timer T1 and starts counting.

Then, when the input time wIX elapses, the input time limit timer T1
operates, and the closing circuit of the section switch ASS2 is energized by the closing of the output contact Rya of the closing relay Ry responsive to its output, and the section switch ASS2 is closed. At the same time, the detection timer T2 starts counting, and the memory relay K stores the operation output of the closing timer T1. In this case, when the section switch ASS2 is turned on, there is an accident in the section (2), so the distribution line breaker CB of the substation P is shut off again before the detection timer T2 finishes counting for a certain period of time. Therefore, since the memory relay continues to store the operational output of the closing timer T1, the starting circuit of the closing timer T1 is locked by its output contact Kb.

Therefore, the sectional switch AS82 that shares the fault section is closed and locked, so when the distribution line breaker CB of the substation P is closed again, power is sequentially transmitted to the healthy sections excluding the fault section at X time intervals. That will happen.

[Problems to be Solved by the Invention] As described above, the conventional distribution line accident investigation device closes the sectional switch when the closing time X has elapsed after voltage is applied from the power line at the sectional point of the sectional switch. Furthermore, if the power goes out before the detection time limit Y elapses, the sectional switch is opened and the closing is locked for subsequent voltage application. For this reason, even if there are no accidents in the assigned section, distribution line accidents may occur due to repeated irregular voltage drops and recoveries due to natural phenomena such as snow damage in the power supply system beyond the substation, or due to system switching operations. If a series of power outages and power transmissions similar to those described above were to occur, certain accident investigation devices on each distribution line would lock at the same time, causing widespread disruption and power outages. . Therefore, if such a situation occurs, a worker must go to the site and manually unlock the accident investigation device, resulting in a decrease in customer service and a reduction in labor for the site worker. There were many problems such as an increase in

Therefore, the present invention solves power outages on power distribution lines caused by factors on the power supply side of substations, and eliminates erroneous and unnecessary power-on locking operations due to power transmission.It also improves the timed sequential transmission system at that time to enable instantaneous sequential transmission to customers. The purpose of the present invention is to provide an accident investigation device for power distribution lines that can improve service and reduce labor for workers.

[Means for Solving the Problems] In order to achieve the above-mentioned objects, the present invention divides the distribution line connected to the distribution line breaker of the substation into multiple sections, and In the accident investigation device installed corresponding to each section switch whose closing circuit is energized by the line voltage and turned on, there is a ground fault detection section that detects ground faults in distribution lines, and a ground fault detection section that detects short circuits in distribution lines. I will lol
i Grating Accident Detection 1 The no-voltage detection section detects that the power supply side line at the division point is no voltage by the division switch, and the ground fault or short circuit of the distribution line is detected by the ground fault detection section or short circuit detection section. distribution line accident determination means comprising a logic section that outputs an accident determination signal when an accident is detected and the no-voltage detection section detects that the power supply side line at the dividing point has no voltage; When an accident determination signal is output from the logic section of the wire accident determination means, a seasonal change storage section stores the determination signal, and when voltage is applied from the power supply line at the division point, it starts counting and sets a predetermined turn-on time. a closing time limit section that operates when the closing time limit section operates, a detection time limit section that starts counting when the closing time limit section operates and resets the storage section by operating when a predetermined detection time limit has elapsed; An accident investigation comprising a closing lock storage section that stores when an accident determination signal is output from the logic section until a predetermined detection time limit is completed, and locks the closing time limit section in an inoperable state. means, the closing circuit of the sectional switch is configured to operate when the accident determination signal output from the logic section of the distribution line accident determination means is not stored in the accident storage section or when the closing time limit section is operating. It is characterized in that it is excited only when

[Operation] Therefore, in the accident investigation device having such a configuration, when a ground fault or short circuit accident occurs in the distribution line, the accident determination signal output from the distribution line accident determination means is stored in the accident investigation means. If this distribution line fault is not in the distribution section, the power supply side line voltage at that division point is applied to the closing time section by restarting the distribution line breaker at the substation, and the predetermined closing RF period has elapsed. The closing circuit of the rear section switch is energized, and when the detection timer starts counting and a predetermined detection time has elapsed, the memory section is reset, so the section switch is locked in the event of a subsequent power outage. Never. In addition, if the distribution line accident is in the own section, the distribution line accident determination means will output an accident determination signal before the detection time limit section finishes counting, so the closing lock storage section will store the determination signal and close the connection. Locks the timer inactive. As a result, if the power distribution circuit breaker at the substation is turned on again and again, the fault determination signal will not be stored in the storage section of the section switches in other healthy sections except for the fault section, so the power supply side line at that section will be closed. The closing circuit is excited by the voltage and is turned on sequentially.

On the other hand, even though there are no distribution line accidents, irregular voltage drops 9 are repeated in the power supply system beyond the substation due to natural phenomena such as snow damage, or distribution line accidents occur due to system switching operations. In the event of a power outage or power transmission, no accident determination signal is output from the distribution line accident determination means, so no accident determination signal is stored in the storage section of the accident investigation means. Therefore, when power transmission is started from the substation side, the closing circuit of each section switch is instantaneously excited and closed by the power supply line voltage at that section point.

[Example code] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the circuit configuration of an accident investigation device according to the present invention, which is provided corresponding to each division switch that divides a distribution line connected to a distribution line breaker in a substation. In Figure 1, ASS is a sectional switch installed at a sectional point of the distribution line, and Tr is a power transformer connected to the power supply line at the sectional point and whose secondary output voltage excites the closing circuit of the sectional switch ASS. It is a vessel. On the other hand, CR is an accident investigation device provided corresponding to the sectional switch ASS, and this accident investigation device OR is a distribution line accident determination means A.

It consists of an accident investigation means B and a switching means C that opens and closes the closing circuit of the sectional switch ASS whose power source is the power transformer Tr.

Distribution line fault determination means A includes a current transformer 3CT that detects the current flowing in the distribution line, and an overcurrent detector OC1 to which the output current from each current transformer CT of the current transformer 3CT is input. Zero-phase transformer 3PD that detects the zero-phase voltage generated when
, a ground fault detector FD to which the zero-sequence voltage output from the zero-sequence transformer 3PD and the zero-sequence current obtained from the collective composite value of the current transformer 3CT are input, and the secondary output of the power transformer Tr. No-voltage detector VC1 to which voltage is input; OR circuit OR to which the outputs of overcurrent detector ○C and ground fault detector FD are input; Flow means 310, and is an expression to clarify the distinction from zero-sequence voltage Va and zero-sequence current Is in the symmetric coordinate method. Incidentally, the zero-sequence voltage Vo in the symmetric coordinate method is VO-(Va+Vb+VC)/3
゜Zero-sequence current IO is In − (Ia + Ib + Ic)/
3. Here, when an overcurrent flows through the distribution line during a short circuit accident or overload, the overcurrent detector OC detects this overcurrent and outputs a signal of logic "1", and the ground fault detector FD outputs a signal of logic "1". When the zero-sequence voltage from the phase transformer 3PD and the zero-sequence current from the current transformer 3CT are input, a ground fault in the distribution line is detected from the magnitude and vector phase relationship, and a logic "1" signal is output. , Furthermore, the no-voltage detector VC detects that there is no secondary output voltage of the power transformer!Tr and outputs a signal of logic "1".In addition to the above-mentioned method, there are other ground fault detection elements. Zero-sequence voltage 3Vo output from zero-sequence transformer 3PD or zero-sequence current 31a obtained from the collective composite value of current transformer 3CT
It is also possible to output a signal of logic "1" by ANDing the output of the absolute value of and the output of the no-voltage detector VC.

Accident investigation means B is AND circuit A of distribution line accident determination means A
When an accident determination signal, that is, a logic "1" is input from ND1, the memory relay that memorizes it starts counting when voltage is applied from the 1 power supply transformer Tr, and operates when a predetermined turn-on time X has elapsed. Closing timer T1, when the closing timer T1 operates, the closing relay Ry1 responds by its output; when the closing timer T1 operates, it starts counting, and when a predetermined detection time Y elapses, it operates, and its output triggers the memory relay K. The detection time limit timer T2 to be reset, a logic "1" signal output from the time when the detection time limit timer T2 starts counting until it ends, and an AND circuit ANDI generate an accident determination signal, that is, a logic "1" signal. AND circuit AND2 that outputs a logic “1” signal when input at the same time
and a closing lock memory relay X that stores the logic signal "1" outputted from this AND circuit AND2 as a closing lock state. A contact Ka and a normally closed contact Xb of the closing lock memory relay X are provided in series.The closing lock memory relay X is resettable by a return switch.

The switching means C for opening and closing the closing circuit of the sectional switch ASS connects the power transformer Tr and the sectional switch ASS by connecting the normally open contact Rya of the closing relay Ry and the normally closed contact Kb of the memory relay in parallel.
It is constructed by installing it in the electric circuit connecting the excitation coils.

Next, the operation of the distribution line accident investigation bit configured as described above will be described.

Now, in the distribution system as shown in Figure 2, assuming that power is being transmitted normally from the substation P side through the distribution Ill, the accident investigation device corresponding to each section switch ASS is as follows. is in a state. That is, the output of the AND circuit AND1 of the distribution line fault determination means A is 0'' and the memory relay K is in the reset state, so its normally open contact Kb is closed.Therefore, the excitation coil of the sectional switching BASS is It is constantly excited by the secondary output voltage of the power transformer Tr through the normally closed contact Kb.

Under such conditions, if a ground fault or short circuit occurs at point F in the distribution line, for example, in section ■, the distribution line breaker CB operates to interrupt the distribution line due to the operation of a protection device (not shown) in the substation P. do. Accordingly, all the accident investigation devices CR corresponding to the sectional switches ASS on the substation side from the accident point are determined to be an accident by the distribution line accident determination means A. In other words, the output signal of the ground fault detector FD or excessive current detector QC becomes logic "1" and is added to the AND circuit ANDI. The output of voltage detector VC is logic “1”
'' and is added to the AND circuit AND1, so the output of the AND circuit AND1 becomes logic 1, and the accident determination signal is stored in the storage relay K of the accident investigation means B. Therefore, the closing timer T1 of the accident investigation means B connects the normally open contact Ka of the memory relay provided in its starting circuit.
is closed, so it is in a standby state for starting, and the normally closed contact Kb of the switching means C provided in the closing circuit of the section switch ASS is open. After a certain period of time, substation P
When voltage appears in the section of the distribution line due to the reopening of the distribution line breaker CB, the accident investigation device CR corresponding to the sectional switch ASSI operates as shown in FIG. 3(a). That is, in this accident investigation device CR, when a voltage appears in the section, the voltage is applied from the power transformer Tr to the turn-on timer T1 of the accident investigation means B, and starts counting. Then, when the closing time limit X has elapsed, the closing timer T1 operates, and the normally open contact R of the closing relay Ry responds to the output of the closing timer T1.
Due to the closing of ya, the excitation coil of the section 1711 closing switch ASS1 is excited, and the section switch As51 is closed. At the same time, the detection timer T2 starts counting, but since there is no accident in section H, there is no power outage while the detection timer T2 is counting for a predetermined time. Therefore, since the accident determination signal is not stored in the closing lock storage relay X before the detection timer T2 passes a certain period of time, the normally closed contact xb provided in the starting circuit of the closing timer T1 remains open. When the detection timer T2 operates after a certain period of time has elapsed, it resets the memory relay K, so the normally closed contact Kb of the opening/closing means C is closed, and the normally open contact Ka provided in the starting circuit of the closing timer T1 is opened. .

Next, when the voltage appears in the section ■ by turning on the section switch As51, the accident investigation device O corresponding to the section switch As52
R operates as shown in FIG. 3(b). That is, when a voltage appears in the interval (3), that voltage is applied from the power transformer Tr to the turn-on timer T1 and starts counting. Then, when the closing time limit X has elapsed, the closing timer T1 operates, and the output contact R of the closing relay Ry responds to the output of the closing timer T1.
The closing circuit of ya excites the closing circuit of the section switch As52, and the section switch As52 is closed. When the section switch ASS2 is turned on, there is an accident in section ■, so before the detection timer T2 finishes counting for a certain period of time, the distribution line breaker CB of the substation P shuts off again, and each section switch ASS is disconnected. Open all at once. At this time segment switch ASS
In the accident investigation device CR corresponding to 2, the accident determination signal is stored in the closing lock storage relay X of the accident investigation means B, so the normally closed contact xb provided in the starting circuit of the closing timer T1 opens and locks. Since the fault determination signal is still stored in the memory relay, the output contact K provided in the excitation circuit of the sectional switch ASS2
b remains open.

Therefore, when the distribution line breaker CB of the substation P is closed again, the sectional switch As51 has the memory relay K of the accident investigation means B in the set state, as shown in FIG. 3(a).
Since its normally open contact Ka is open, it will be closed after the
As shown in Figure (b), the circuit is not closed because it is locked.

In this way, when the distribution circuit breaker CB of the substation P is turned on again and again, the fault section is removed (the fault determination signal is not stored in the memory relay K for the section switches of other healthy sections, so the section switch of that section point is The power-on circuit is excited by the power supply line voltage and is sequentially turned on.

Next, a case will be described in which an instantaneous fault occurs at point F in the diagram, for example, in section (3) of power distribution IL. In this case, as shown in Figure 3 (C), when the distribution line breaker CB operates to disconnect due to the operation of the protective device, the circuit breakers ASS for each section open simultaneously, and the fault point is connected to the substation. The accident investigation device CR corresponding to the side sectional switch Ass is all determined to be an accident by the distribution line accident determination means A. Along with this, the accident investigation devices CR corresponding to the sectional switches ASS on the substation side from the accident point are all judged as accidents by the distribution line accident determination means A as described above, and an accident determination signal is sent to the memory relay K of the accident investigation means B. be remembered. Therefore, the closing timer T1 of the accident investigation means B is in a starting standby state because the normally open contact Ka of the memory relay provided in the starting circuit is closed, and the closing timer T1 of the accident investigation means B is in a starting standby state because the normally open contact Ka of the memory relay provided in the starting circuit is closed. The normally open contact Kb of the switching means C is open. - After a fixed time period has elapsed, when voltage appears in the section of the distribution line due to the reopening of the distribution line breaker CB of the substation P, the accident investigation device CR corresponding to the sectional switch ASSI will act as shown in Figure 3 (C). It behaves as shown. That is, in the accident investigation device corresponding to the section switch ASS1, the closing timer T1 starts counting and when a predetermined period of time has elapsed, the closing relay Ry is operated by the operation output, and the section switch ASS1 is closed by closing the normally open contact Rya. Injected. At the same time, the detection time limit timer T2 starts counting and operates to reset the memory relay K when the detection time limit has elapsed.

When the voltage appears in section ■ of the distribution line due to the closing of the sectional switch ASSI, the accident investigation device CR corresponding to the sectional switch ASS2 starts the operation of the distribution line when the distribution line breaker CB of the substation P is reclosed. Since the accident has been removed, the operation is exactly the same as in the case of the accident investigation wave @cR corresponding to the sectional switch As51, and the sectional switch ASS2 is closed.

In this way, if the fault in the power distribution 1i1L is instantaneous, each section switch ASS will be sequentially sent from the substation side at X time intervals.

On the other hand, there is no fault in the distribution line, and the power supply system beyond substation P has irregular voltage drop 2 due to natural phenomena such as snow damage, repeats recovery, or is similar to the case where the fault occurred in the R line due to system switching operations. A series of stops.

When power is transmitted, the following operations occur.

That is, as shown in Fig. 3(d), all the section switches ASS are opened at the same time due to a power outage on the substation side, but in this case, the fault is not determined by the fault determining means A because it is not an accident in the distribution line. No signal is output, so the storage relay K of the accident investigation means B does not store the accident determination signal and is in a reset state. This causes the normally closed contact K in the memory relay to
Since the circuit b remains closed, when the power supply on the substation side is restored and power transmission is started, each section switch ASS is turned on instantly when voltage appears on the power line at that section point.

The above has been explained using an example in which the short circuit current or ground fault current flowing in the event of an accident in a distribution line is in the same direction as the power transmission direction, but the accident determination means A of the accident investigation device CR provided corresponding to each section switch ASS is explained above. Since the ground fault detector FD has the function of detecting the direction of a ground fault, for example, if a ground fault occurs in section ■ of the distribution line L1 in the distribution system as shown in Fig. 4, Other distribution line L2.・・・・・・
, In, the accident determination means A of the accident investigation device corresponding to each section switch does not make an accident determination, and therefore, when the distribution line breaker CB of the substation is reclosed, the distribution line L2゜...
. . , each section switch ASS of l-n is turned on instantly.

[Effects of the Invention] As described above, according to the present invention, when a ground fault or short circuit accident occurs in a distribution line, the storage section of the accident investigation means is activated by an accident determination signal output from the distribution line accident determination means. If the distribution line accident is not in the distribution section, the distribution line breaker at the substation is reopened to the 1st division point! The source line voltage is applied to the closing timer, and after a predetermined closing time has elapsed, the closing circuit of the sectional switch is energized, and the detection timer starts counting, and when the predetermined detection time has elapsed, the memory section is reset. to prevent the sectional switch from closing and locking in the event of a subsequent power outage, and if the distribution line accident is in one's assigned section, the fault judgment is output from the distribution line fault judgment means before the detection timer has finished counting. Since the signal is stored in the closing lock memory section and the closing time limit section is locked in an inoperable state, when the distribution circuit breaker at the substation is closed again and again, the sectional switches in other healthy sections except the fault section are closed. In addition, the power supply system beyond the substation can experience repeated irregular voltage drops and recoveries due to natural phenomena such as snow damage, or a series of distribution line accidents similar to those caused by grid switching operations. If power is stopped and power is transmitted, the distribution line accident will not be stored in the memory of the accident investigation means, so unlike in the past, specific items on each distribution line will be locked at the same time, causing a widespread power outage. When power transmission starts from the substation side, each section switch is turned on instantly, minimizing the extent of power outage, improving customer service, and reducing the labor required for workers. It is possible to provide a distribution line accident investigation device that can perform the following tasks.

[Brief explanation of the drawing]

Fig. 1 is a circuit configuration diagram showing an embodiment of the power distribution line accident investigation device according to the present invention, Fig. 2 is a power distribution system diagram to which the embodiment device is applied, and Fig. 3 explains the operation of the embodiment. FIG. 4 is a power distribution system diagram when the same embodiment device is applied to multiple distribution lines, FIG. 5 is a power distribution system diagram for explaining the timed sequential transmission system, and FIG. The figure is an open circuit diagram showing a conventional accident investigation device, and FIG. 7 is a diagram showing a time chart for explaining the operation of the device. L...Transmission line, ASS...Division switch, Tr...Power transformer, CR... Accident investigation device, A...... Distribution line accident determination means, B...
...Accident investigation means, C...Opening/closing means, 3C
T...Current transformer, ○C...Overcurrent relay, 3PD...Zero phase transformer, FD...Ground fault detector, VC...・・・・・・No-voltage detector, OR・
...OR circuit, ANDl, AND2...
AND circuit, K...memory relay, T1...
... Closing timer, T2... Detection timer, Ry... Closing relay, X... Closing lock memory relay. Applicant's agent Patent attorney Takehiko Suzue Licensed patent attorney K Kb --- (d) Figure 5 Figure 6

Claims (2)

[Claims] (1) The distribution line connected to the distribution line and disconnector of the substation is divided into multiple sections, and the closing circuit is excited by the power supply line voltage at the division point and connected to each section switch. In the corresponding accident investigation equipment, there is a ground fault detection section that detects ground faults in distribution lines, a short circuit detection section that detects short circuits in distribution lines, and a section switch that detects when the power supply side line at the division point is disconnected. A ground fault or a short circuit accident in the distribution line is detected by the no-voltage detection unit that detects voltage, and the ground fault detection unit or short-circuit detection unit, and the non-voltage detection unit detects that the power supply side line at the dividing point is detected. Distribution line accident determination means is composed of a logic section that outputs an accident determination signal when it is detected that there is no voltage; A memory section that stores signals, a closing timer section that starts counting when voltage is applied from the power supply line of the dividing point and operates when a predetermined closing time elapses, and a closing timer section that starts counting when this closing timer section operates. A detection time limit section operates to reset the storage section when a predetermined detection time limit elapses, and an accident determination signal is output from the logic section between the time the detection time limit section starts counting and the predetermined detection time limit is completed. and an accident investigation means constituted by a closing lock storage section which memorizes the fact and locks the closing time limit section in an inoperable state, and the closing circuit of the sectional switch is connected to the distribution line in the storage section. An accident investigation device for a power distribution line, characterized in that it is energized only when an accident determination signal output from a logic section of an accident determination means is not stored or when the closing time limit section is operating. (2) When power is transmitted after the substation power is stopped, the closing circuit of the sectional switch is instantaneously activated by the line voltage on the power supply side of the sectional switch through the contact that closes when no fault determination signal is stored in the memory. The power distribution line accident investigation device according to claim 1, which is excited.