KR0139603B1 - Distribution power line break-down section automatic opening and shutting controller - Google Patents

Abstract

The present invention relates to an automatic opening and closing control device for the fault line of a distribution line, and when a phase current and ground fault current are generated by currents flowed from three current transformers, the ground current is full-wave rectified by a matching transformer to ensure reliable phase and ground fault. When the line current decreases below a certain value during light load operation or after failure detection, it adopts its own voltage and current method that divides the voltage of the relative ground, not an external auxiliary power supply, into a high voltage capacitor and matching transformer. If the fault current is more than 800A and the COR or OCGR is operated when it lasts for 1 ~ 1.5 cycles after the fault detection by the transient or permanent fault discrimination unit or the back protection device is operated, the lock current In the no-voltage non-current state, which is locked by the detection unit and the after-protection device operates, the output unit is activated by a zooming operation. It is to make tripping current to generate trip current so that stable and convenient failure section is automatically opened and closed.

Description

Automatic opening / closing control device for fault section of distribution line

1 is a block diagram showing a schematic configuration of the present invention.

2 is a circuit diagram showing a detailed configuration of the present invention.

(A) and (b) of FIG. 3 are waveform diagrams showing the operating states of transient failure due to permanent failure and lightning strike, respectively.

* Explanation of symbols for main parts of the drawings

1: Phase current forming part 2: Power supply voltage part

3: ground detection unit 4: upper detection unit

5: OCGR 6: OCR

7: Lock current detection unit 8: Transient permanent failure determination unit

9: Power supply detail 10: Inrush current suppression unit

11: output section 12: fault display section

The present invention relates to an automatic opening and closing controller arch of the distribution line, and more particularly, to an automatic opening and closing control device of the failure line of the distribution line to operate only in the case of permanent failure by determining whether excessive or permanent failure due to lightning strike. .

In the 22.9KV distribution system of the neutral point multi-grounding system, it is installed at the branch point or the customer entrance of the load capacity below 8000KVA and cooperates with other protection devices (CB, RECLOSER) of the line in case of overload or failure, so that only the failure section is blocked or opened. Automatic opening and closing control device is used.

Conventionally, as in Patent Publication No. 86-1479, when the timing is completed before the post protection device operates for the fault current below the rated breaking current, the block is directly opened. On the other hand, in case of failure over rated breaking current, it is allowed to make small opening at one time so that the failure section can be separated from the distribution system regardless of the breaker (CB) or the closure (RECLOSER).

However, according to the conventional failure zone automatic opening and blocking device as described above, if the after-protection device performs instantaneous operation to remove the transient failure, it detects it and locks it out. Therefore, the transient failure is regarded as a permanent failure. There was a disadvantage of causing unnecessary power outages on the track.

Therefore, as in Patent Publication No. 92-9853, it is installed between the rear end of the circuit breaker or the recloser and the front end of the load to form a phase voltage proportional to the line by inputting the current generated from the current transformer. Phase-current timing means for generating the phase-time timing signal by judging whether there is a fault current according to the current, and a ground voltage that is proportional to the line is formed by inputting the current generated from the current transformer. A ground fault time-current timing means for determining whether there is a fault current and generating a ground fault time-current timing signal;

Output means for activating the trip coil according to the output signal of the ground time-current timing means to turn off the switch;

An instantaneous timing means for detecting an instantaneous level generated in a line and generating an instantaneous timing signal;

Ground fault timing means for detecting ground fault levels generated in a line and generating phase timing signals;

When the lock current of the rated breaking current flows on the line, it detects this and interlocks means to suppress the output of the timing means input to the output means to prevent tripping of the trip coil. The coefficient open method is added to the broad time-current characteristic function, and the time current characteristic function and the selective shaft open and coefficient open functions are combined with each other even in the current of more than lock, so that it can be judged logically in the event of a fault. Protection coordination with other protective devices or devices has been made possible.

However, the conventional control device as described above uses the control power by the current transformer, so it is difficult to secure the control power during light load operation, so a separate auxiliary power is required, and when the line current decreases below a certain value after a fault detection, the lockout is performed. Since the counting function is adopted three times to confirm that there is a transient failure, the back protection device may perform unnecessary operation or experience a fault current again, resulting in power failure in a healthy section or an accident.

Accordingly, the present invention adopts its own voltage and current method to provide a device for automatically opening and closing a failure section of a distribution line so as to operate only during a permanent failure while eliminating the fear of malfunction during light load operation or failure detection, and identifying transient and permanent failure. For that purpose.

In order to achieve the above object, the present invention generates a ground current and a ground fault current by currents flowing from three current transformers, and passes the matching transformer so that the ground fault current is full-wave rectified to detect a certain phase and ground fault. and,

It adopts its own voltage current method that divides the voltage of the relative ground, not the external auxiliary power source, with a high voltage capacitor and a matching transformer, so that there is no malfunction when the line current decreases below a certain value during light load operation or after failure detection. OCR or OCGR operates in case of lasting 1 ~ 1.5 cycles after fault detection by the transient or permanent fault discrimination unit or when the protection device is operated, and if the fault current is more than 800A, it is locked by the lock current detector. In the no-voltage non-current state in which the protection device operates, the output unit is operated by the pinion operation to generate a trip current so that the automatic opening and closing of a stable and convenient failure section is performed.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Phase current forming unit 1 for proportionally detecting the magnitude of the current flowing in the distribution line,

A power supply voltage unit 2 which receives the current of the distribution line via the sexual current forming unit 1 and outputs the current at a reference voltage and a control voltage;

A ground fault detection unit (3) for receiving a phase current from the phase current forming unit (1) to form a ground fault voltage proportional to the line current and determining the presence of a fault current according to the ground fault voltage;

A phase detection unit 4 which receives a phase current from the phase current forming unit 1 and forms a phase voltage proportional to the line current and determines whether there is a fault current according to the phase voltage;

Operation characteristics that cooperate with the damage characteristic curve of the transformer, the operation characteristics of the back protection device, and the fuse characteristic curve while operating at an operation timing proportional to the line current by the outputs of the ground fault and the phase detectors 3 and 4. Over Current Ground Relay (OCGR) (5) and Over Crurrent Relay (OCR) (6),

When the output from the phase detection unit 4 is a large fault current equal to or greater than the rated breaking current 800A, the lock is locked. A current detector 7,

In order to determine whether the outputs of the ground fault and the phase detection units 3 and 4 are transient failures due to lightning, tidal currents or tree contact, etc., a predetermined delay time (1 to 1.5 cycles) is provided after the failure is detected, A transient / permanent fault discrimination unit (8) which outputs a signal for normal control operation or an open drive according to the state of extinction or the rear protection device;

A power supply detail section 9 for outputting a trip driving signal in a state where there is a no-current non-voltage state by the post-protection device and there is an output of the OCGR 5 and / or OCR 6 above;

In the event of failure while performing the inrush preparation function by the determination function of the transient / permanent fault discrimination unit 8 above, and preventing the pick-up for a predetermined time during re-pressurization when the voltage is in a no-voltage state at a normal current. Inrush current suppression unit 10 to be picked up immediately when re-join the track,

Output that turns off the switch by selectively operating the trip coil under the influence of the lock detection unit 7 and the transient / permanent failure discrimination unit 8 while operating by the output of the OCGR 5 and the OCR 6 above. Section 11,

According to the output of the OCGR (5) and OCR (6) is composed of a failure display unit 12 to confirm the presence or absence of a failure.

2 is a detailed circuit diagram of the present invention, which is installed at a branch point having a load capacity of 800KVA or less or a customer inlet in a 22.9KV distribution system of a neutral point multi-grounding system, in case of an overload or breakdown accident (circuit breaker, recloser). ) In order to block or open only the fault section, and the current of the normal line is detected as a voltage proportional to the line by the current transformers 1a, 1b, and 1c installed in each phase (RST) and then the capacitor (Ca). ), (Cb), (Cc), and (Cd) and the matching transformer (T) and rectifier circuit (BD1) through the rectifier circuit (BD2) in the forward direction as detected as a ground fault (video) current It is detected as phase current.

The ground fault current turns on / off the transistor TR1 of the ground fault current detection unit 3, and the current flowing through the transistor TR1 is applied as the comparison voltage of the comparator A1, and the output of the comparator A1 is a transistor. Since the transistor TR3 of the OCGR 5 is turned on / off after being inverted by TR2, the state of charge of the capacitors C1 and C2 is controlled, and the ground fault current turns on the transistor TR4. The charging current is selectively flowed to the capacitors C1 and C2, and the charging current of the capacitors C1 and C2 is applied as an alternating voltage of the comparator A2, and its output is outputted. The transistor TR5 of (11) is turned on / off, but the transistor TR6 connected in series with its emitter is selectively turned on / off by the lock current detection unit 7. FIG.

The current value inverted by the transistors TR5 and TR6 allows the trip output to be output while selectively turning on the SCR (S) via the transistor TR7.

On the other hand, the phase current described above turns on / off the transistor TR9 of the phase current detection unit 4, the current flowing through the transistor TR8 is applied as the comparison voltage of the comparator A3, and the output of the comparator A3 is a transistor. Since the transistor TR10 of the OCR 6 is turned on / off after being inverted by TR9, the state of charge of the capacitors C3 and C4 is controlled, and the acid current turns on the transistor TR11. OFF to allow the charging current to selectively flow in the capacitors C3 and C4, and the charging current of the capacitors C3 and C4 is applied as the comparison voltage of the comparator A4, and its output is output 11. Transistor TR5 is turned on / off.

The fault current of 800 A or more causes the comparison voltage of the comparator A5 to increase while the transistor TR5 of the lock current detection unit 7 is turned on, and the transistor TR6 is turned on by the output of the comparator A5. Off).

In the case of ground fault or high fault, the transistors TR2 and TR9 are turned on, respectively, and the transistors TR16 of the transient / permanent failure determination unit 8 are turned off by the diodes D1 and D2, and the comparator A6 is turned on. The output of the comparator A6 goes low only while the comparison voltage of C) is charged to the capacitor C5, that is, for 1 to 1.5 cycles, so that the transistor TR19 of the power storage section 9 is turned off and after 1 to 1.5 cycles. The transistor TR7 of the output unit 1 is turned on while the transistor TR19 is turned on to drive the SCR (S).

The base of the transistor TR18 is connected to the collector of the transistor TR17 turned on / off by the comparator A6, and the base of the transistor TR12 of the fault display unit 12 is connected to the collector of the transistor TR18. To selectively turn off the latch relay lock coil (LR / S) connected to the collector thereof, and the latch relay (LR) turned on by the latch relay set coil (LR / S) divides the resistor (R1) (R2). By adjusting the magnitude of the low voltage applied to one side of the comparator A7 through the comparison with the voltage applied to the other side, the output of the comparator A7 selectively turns on the transistor TR13 while the latch relay reset coil Turn on (LR / L).

Therefore, it is possible to notify the outside of the failure through the display device not shown in the drawing using the latch relay LR as the driving dry contact.

On one side of the comparator A7, when the transistor TR17 connected to the collector through the diode D5 is turned on by the normal state or the manual reset switch SW is turned on, the latch relay reset coil LR / C is turned on. By driving, the latch relay LR is turned off.

On the other hand, in the case of the inrush current suppression, since the output via the diodes D3 and D4 turns on the transistor TR17 according to the output of the transient / permanent fault discrimination unit 8, the inrush current suppression unit 10 The transistor TR21 is turned off so that the next circuit does not operate. When the transistor TR17 is turned off, the back protection device operates to turn off the transistor TR20 because it is in a normal current state. As the transistor TR22 is turned on, the transistor C23 is charged and then the transistor TR23 is turned on. Accordingly, the ground fault detection unit 3 and the phase detection unit are turned on by the transistor TR24 that is turned on when the post-protection device is turned on. Inrush current through the diodes D5 and D6 of (4) is suppressed.

At this time, the operation time is controlled by the time charged in the capacitor C7 connected between the collector of the transistor TR25 and the comparator A8. When the transistor TR25 is turned on, the transistor TR23 is turned off and rushes in. The function of current suppression is reset.

The automatic control circuit for opening and closing sections of the distribution line of the present invention configured as described above is capable of judging whether there is a transient failure or a permanent failure, and the transient failure caused by lightning which occurs the most among the transient failures is shown in FIG. 3 (b). As shown in the figure, abnormal waveforms appear only at 1/2 cycle, and as a result, the abnormal waveforms are 1 to 1.5 cycles as compared to the continuous occurrence of abnormal waveforms as in the case of permanent failure shown in (a) of FIG. It is determined whether the abnormality persists as the charging time of the capacitor C5 in the transient / permanent fault discrimination unit 8.

That is, the phase current and the ground fault current are detected by the full-wave rectification method by the rectifier circuit BD1 (BD2) to ensure the detection of phase and ground fault, and the divided voltage is formed by the transformer T of the high voltage capacitor and the matching transformer. By doing so, even if the line current decreases below a certain value during light load operation or after failure detection, it operates normally without fear of malfunction.

The fault current below the lock current of 800 A is operated by the OCGR (5) and the OCR (6). For the lock current abnormality of 800 A or more, the after-protection device and the cooperative coordination operation are performed according to the detection result of the lock current detector (7). Do it.

Since the current due to the lightning is extinguished within 0.5 cycles to 1.0 cycles, the transistors TR16 and TR9 of the ground and phase detection units 3 and 4 are turned on and the transistors TR16 through the diodes D1 and D2. When the comparison voltage of the comparator A6 charged to the capacitor C5 becomes higher than the reference voltage even after 1.0 to 1.5 cycles, the charging time of the capacitor C5, when the base voltage of the ground is grounded, The switch opens.

In addition, the inrush current generated when the power is supplied to the line again is determined by the transient / permanent failure discrimination unit 8, and the capacitor C6 is charged to the capacitor C6 when there is no voltage and no current. In the event of a failure, you should pick up the fault immediately when re-pressurizing the rail so that you do not prepare for inrush.

Claims (4)

A phase current forming unit 1 for proportionally detecting the magnitude of the current flowing in the distribution line, and a power supply voltage unit receiving the current of the distribution line via the phase current forming unit 1 and outputting it at a reference voltage and a control voltage. (2) and a ground fault detector (3) for determining whether there is a fault current according to the ground fault voltage while forming a ground fault voltage proportional to the line current by receiving the phase current from the phase current forming unit (1), and the phase current forming unit Phase detection unit 4 for inputting the phase current from (1) to form a phase voltage proportional to the line current and determining the presence of a fault current according to the phase voltage, and the ground and phase detection units 3 and 4 described above. Over Current Ground Relay (OCGR) (5), which has an operating characteristic that cooperates with the damage characteristic curve of the transformer, the operating characteristic of the fuse protection device, and the fuse characteristic curve while operating with an operating timing that is proportional to the line current by the output of OCR (Over Current Relay) (6) and when the output from the above-mentioned phase detection unit 4 is a large fault current equal to or greater than the rated breaking current 800A, it is locked. Predetermined delay time after failure detection to determine whether the outputs of the lock current detection unit 7 for outputting a signal and the above ground and phase detection units 3 and 4 are transient failures due to lightning or tree contact. 1 to 1.5 cycles) and the transient / permanent fault discrimination unit 8 which outputs a signal for normal control operation or open drive according to the state where the current flow disappears or the rear protection device operates, and the rear protection device Power supply detail section 9 for outputting a trip driving signal in a state where there is no current and no output of OCGR 5 and / or OCR 6, and the above transient / permanent failure discriminating section 8 It performs normal inrush function by discrimination function and is normal In the case of a no-voltage condition in the current, the inrush current suppression unit (10) and the above-mentioned OCGR (5) An output section 11 which operates by the output of the OCR 6 and selectively turns off the switch by automatically tripping the coil under the influence of the lock detection section 7 and the transient / permanent fault discrimination section 8; The fault opening and closing circuit of the distribution line, characterized in that it consists of a fault display unit 12 to determine the presence or absence of a failure according to the output of the OCGR (5) and OCR (6). The transformer (T) according to claim 1, wherein the phase current forming unit (1) converts the voltage detected by the current transformers (1a), (1b), and (1c) installed in each phase (RST) into a high voltage capacitor and a matching transformer. A circuit for automatically opening / closing a failure section of a distribution line that is detected as a ground fault current and a phase current through a full-wave rectifier circuit BP1 and BD2. 2. The transient / permanent fault discrimination unit (8) according to claim 1, wherein the transient / permanent fault discrimination unit (8) includes a capacitor (C5) when the transistor TR16 turned on by the voltage voltage unit (2) is turned off by the ground fault detector (3) or the phase detector (4). ) Is automatically applied to the comparison voltage of the comparator A6 so that the fault section of the distribution line is automatically judged as a permanent failure in which the transient current is continuously applied for 1.0 to 1.5 cycles charged to the capacitor C5. Switching control circuit. The inrush current suppressing unit 10 determines that the transistor TR17 is turned off due to the output of the transient / permanent fault discrimination unit 10, and determines that the transistor TR21 is turned off so that the next circuit is closed. In the state where the transistor TR17 is turned off, the transistors RR20, TR21, and TR22 are sequentially turned on to turn on the diodes D5 and (the ground detection unit 3 and the phase detection unit 4). Automatic opening and closing control circuit for failure section of distribution line configured to suppress inrush current through D6).