JPS591050B2 - Automatic control device for distribution line switches - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic control device for a distribution line switch, and more particularly to an automatic control device for a distribution line switch that sequentially supplies power to healthy sections in two trial power transmissions.

Conventionally, automatic control devices for this type of distribution line switch include:
A non-voltage line disconnect type sectional switch combined with a timed accident investigation device consisting of a timed relay and its attached circuit is used.

This conventional device is arranged as shown in FIG. 1 for each feeder of a distribution line.

That is, in the power distribution system diagram of FIG. 1, the busbar connection and cutoff 5CB-M of the substation SS is connected to the substation bus BUS, and the protective relays Ry-1t and Ry-2 are connected to the substation bus BUS.

Ry-3...and feeder cutoff 5CB-1,C
Each feeder 1.2, 3, . . . of the distribution line is led out via B-2, CB-3, .

Furthermore, each feeder L2, 3, . S1□・・・S21 j
S22...S31, S3□...
On the power supply side of the voltage detection transformer Tr11 tT]i2
...Tr21, Tr2□...Tr
30. By connecting Tr3□...... respectively, a time-limited accident investigation device T Stl>
T S12 . . . is operated, thereby closing and tripping the section switch.

This time-limited accident investigation 5TS1. ,TS,2...
The specific operation of ・is as explained below.

For example, in FIG. 1, the third section 1 of the first line feeder 1
13, when a ground fault occurs, the protective relay ay-1 of the feeder cutoff ICB-1 operates to open only the feeder cutoff ICB-1, putting the feeder in a no-voltage state.

Therefore, the section opening/closing sections 5S1□, S1□, . . . are opened all at once due to this no voltage.

However, after the predetermined no-voltage time TR, feeder circuit breaker CB-1
reclose the circuit.

As a result of this reclosing, the first section t1 of the feeder 1. will be transmitted after the above-mentioned no-voltage time TR has elapsed, and therefore, the first time-limited fault wave fiTs11 further inputs the section opening/closing 5S1 after the waiting time Tx, and the second section t1 of the feeder 1 is switched on.
Transmit electricity to

The second time-limited accident investigation device TS12 further closes the section switch S12 after the waiting time Tx and enters the third section t1 of the feeder 1.
3. Transmit electricity.

In this case, unless the cause of the accident in the third section t13 is removed, the accident will occur again by closing the sectional switch S12.

Since this accident recurrence time is within the detection time Tr, the sectional switch S12 is locked from being closed after the feeder circuit breaker CB-1 is shut off again.

Thereafter, the feeder circuit breaker CB-1 is reclosed in the same manner as described above, and power is transmitted to the healthy section t1□.

The conventional power distribution configuration shown in Figure 1 has the advantage of not affecting other healthy feeders because only the circuit breaker of the faulty feeder operates, but providing a circuit breaker for each feeder is not suitable for the power distribution system. The disadvantage is that it is quite expensive.

Recently, there has been a demand from an economical point of view to omit the feeder ear disconnector and replace it with a switch having load switching capability, that is, a load switch.

The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a new automatic control device for a power distribution line switch that is economical and can sufficiently shorten the accident investigation time.

The present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a power distribution system diagram according to the present invention, and the parts corresponding to those in FIG.

In the present invention, current transformers 11, 12, 13, .
Load switch S11 y S21, s3
5. Provided between □... and the bus line BUS, respectively. And instrument transformers PT-1, PT-2, PT-3...
・And control device C0NT-1, C0NT-2, C0NT
-3...... are connected in series to the bus line BUS and load switching hs11.

They are provided between S21 t, S3t, and so on, respectively.

In addition, the current transformers 11, 12, 13... are controlled by the control device C0.
Connect to NT-1゜C0NT-2, C0NT-3...

These control devices C0NT-1tCONT-2, C0NT
-3... is current transformer 11, 12, 13...
・Detection current from and potential transformers PT-1, PT-2
゜The load switch S11 of each feeder 1, 2, 3, etc. is operated by the detected voltage from PT-3...
t S215S31... or cutoff 5CB
-M is turned on and tripped.

This circuit breaker CB-M has a control device CONT-M.
is connected, thereby controlling the closing and tripping of circuit breaker CB-M.

Next, the circuit configuration of the main part of the device of the present invention is shown in Figure 1.
The devices installed in the feeder 1 will be explained.

In the figure, the subscript -1 of each symbol means the first feeder.

That is, a zero-phase current transformer ZCT-1 is provided between the bus bar BUS and the load switch S1, and its output side is connected to one input side of the internal ground fault direction detection relay 52-1, and the other input A grounding transformer EEapT-1 is connected between the side and the bus line BUS.

This internal ground fault direction detection relay 52-1 is a current transformer ZCT-
The circuit breaker CB-MK operates in the event of an internal direction fault in response to the zero-sequence current from 15PT-1 and the zero-sequence voltage from the grounding transformer 15PT-1.
! Give a command to disconnect.

Also, internal ground fault direction detection relay 52-1 and load switch S11
A time-limited accident investigation device TS-1 is provided between the circuit breaker CB-M and the load switch S1 to open the load switch S1 after a certain period of time after the circuit breaker CB-M has disconnected.

Furthermore, a current transformer CT-1 is provided between the zero-phase transformer i5Z CT-1 and the load switch Sll, and its output side is connected to the input side of the internal short circuit detector 51-1, and its output side is set to a time limit. Connect to the TS-1 accident investigation system.

The internal short circuit detection relay 551-1 operates in response to the current from the current transformer 5CT-1, and gives a cutoff command to the cutoff i5c B-M in the same manner as described for the internal ground fault direction detection relay 552-1. At the same time, the time-limited accident investigation device TS-1 is activated, and after a certain period of time after the circuit breaker CB-M is disconnected, the load switch SL is activated.
Let l open.

The operation of the apparatus of the present invention constructed as described above will be explained below with reference to the time chart of FIG.

It is assumed that a ground fault occurs in the third section t13 of the second line feeder 1.

In this case, since a ground fault current flows through feeder 1, zero-phase current transformation 5
A zero-sequence current is detected in ZCT-1 and the grounding transformer P
A zero-sequence voltage is detected at T-1, and the internal ground fault direction detection relay 552-1 is operated by these currents and voltages.

At this time, for the second line feeder and subsequent lines, the internal ground fault direction detection relay 52-2゜52-
3... remain inactive.

When the internal ground fault direction detection relay 552-1 operates, it is shut off iC.
A tripping command is given to the control device CONT-M connected to B-M, and the time-limited accident investigation device TS-1 is operated, and after a time TX, an opening command is given to the load opening/closing is1.

Simultaneously with this opening command, the timer circuit of the time-limited accident investigation device TS-1 is activated, and after a time TX', the load switch S1 is activated.
Give the input command to 1.

When the time TX elapses after the load switch S1□ is closed, the accident investigation 5T S1□ operates and gives a close command to the sectional switch S1□.

Further, when the time Tx has further elapsed after the sectional switch S1□ is closed, the sectional switch S13 is closed by the accident investigation device T813.

In this case, if the cause of the accident still remains in the third section t13 of the feeder 1, the ground fault will occur again, and the load switch Sll will be cut off again by the operation of the relay 52=1.

In this case, since the section switch 813 becomes non-voltage within the time Tv after re-closing, it is assumed that the closing is locked at the time of subsequent re-closing.

The load switch S11 is reclosed in the same way as described above after the time T x' has elapsed after the re-shutoff, and after a further time Tx, the load switch S11 is switched on and off again in the section 5.
S12 is reclosed.

However, as described above, the section switch S13 remains open and does not close again.

As described above, according to the present invention, in the event of a ground fault, only the feeder in which the failure has occurred is sequentially turned on, or investigated, so that there is no possibility of power failure in other healthy phases.

It is assumed that the re-closing command for the parent/bus line contact circuit breaker CB-M is flexibly executed when the load switch Sll is closed twice.

Next, a case where a short circuit accident occurs in the third section t13 of the first line feeder 1 will be described.

In this case, the short circuit current flowing through feeder 1 is the current transformer CT
-1 is detected, and this current operates the internal short circuit direction detection relay 551-1, which causes the circuit breaker side (goods) to operate.
A tripping command is given to the installed ficONT-M, and the time-limited accident investigation device TS-1 is activated for the time T shown in Fig. 4.
? Afterwards, an opening command is given to the load switch S1.

Simultaneously with this opening command, the timer circuit of the time-limited accident investigation device TS-1 is started, and after a long period of time, it operates again to apply a closing phase to the load switching SS,1.

Furthermore, according to the present invention, when the open command is issued in load switching 1s11, the busbar communication disconnection ICB-LM is open, but in this case, it is connected in parallel to the breaker CB-M and acts as a current limiting element. Since the resistor R is inserted in series in the power distribution system, the short-circuit current is suppressed to below the ground fault current, and therefore opening with the load switch Sll becomes effective.

When a time Tx has elapsed after closing the load switch Sll, the fault investigation device TS12 gives a closing command to the segment switch S12, and when a further time Tx has elapsed after the segment switch S1□ has closed, the fault wave IE5TSt3 causes the segment switch 5S13 to close. be done.

In this case, if the cause of the accident still remains in the third section t13 of the feeder 1, the short circuit will occur again and the internal short circuit direction detection relay 51-1 will operate to cut off the load switch S11.

In this case, since the sectional switch S13 becomes non-voltage within the time Ty after re-closing, it is assumed that the closing is locked at the time of subsequent re-closing.

The load switch S11 is reclosed in the same manner as described above after a time Tx' has elapsed after the re-shutoff, and the section switch S1□ is reclosed after a further time Tx.

However, as described above, the section switch S13 remains open and does not close again.

As described above, according to the present invention, in the event of a short-circuit accident, only the feeder in which the failure has occurred is sequentially turned on, ie, investigated, so that other healthy phases are not interrupted.

The re-closing command for the parent/bus line connection disconnection 5CB-M shall be issued on the condition that the load switch Sll has been closed twice.

In the example shown in FIG. 2 described above, a resistor R is installed in parallel with the busbar connection cut-off 5CB-M, but a reactor L as shown in FIG. 5 may be used as a current limiting element instead of the resistor 5R.

That is, the configuration shown in FIG. 5 and the configuration shown in FIG. 2 differ only in the resistor R and reactor L.
Since other points are completely the same and exhibit the same functions, a brief explanation of the fifth drawing will be omitted.

As described above, according to the present invention, the conventionally used feeder circuit breaker is omitted, and the sectional switch closest to the bus bar has the ability to interrupt the current of the sum of the load current and the ground fault current. By using a so-called load switch, only the faulty feeder can be investigated in the event of both ground fault and short circuit accidents, which is economical, localizes the area of power outage, and shortens power outage time. We can provide automatic side (goods) devices for switchgears.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a conventional power distribution system, Fig. 2 is a block diagram showing a power distribution system according to the present invention, Fig. 3 is a block diagram showing the configuration of the main part of the device of the present invention, and Fig. 4 is a block diagram showing the structure of the main part of the device of the present invention. A time chart for explaining the operation of the device, and FIG. 5 is a block diagram showing another example of the power distribution system according to the present invention. CB-M...Busbar connection breaker, B[JS...Substation busbar, Sll j 821 j S31...Load switch, S1□. S13 t S2□ t S23 , S32 ,
S33... Sectional switch, TS12, T Sts
, TS22 , TS23 t TS32
. TS33...Timed accident investigation device, TS-1...Timed accident investigation device, ZCT-1...Zero phase current transformer, CT-
1...Current transformer, PT-1, PT-2, PT-3 ground transformer EE device, C2,3...Feeder, 11,12.13.
... Current transformer, 52-1 ... Internal ground fault direction detection relay,
51-1...Internal short circuit detection relay, C0NT-1°C
0NT-3, CONT-M... control equipment, t11
~t33...Feeder section, Tr11~Tr33
...Voltage detection transformer, R...Current limiting resistor, L.
・Current limiting reactor.

Claims (1)

[Scope of Claims] 1. A substation bus connected to a power source via a busbar connection breaker, a cross-current element installed in parallel to the busbar connection breaker, and connected to the busbar via a load switch. A plurality of feeders each having a sectional switch for each section and a timed accident investigation device that sequentially controls the sectional switches, and a plurality of feeders provided for each feeder to prevent internal ground faults and/or internal short circuits. An automatic control device for a distribution line switch, comprising a control device that trips the busbar communication breaker upon detection, opens the load switch of the faulty feeder after a certain period of time, and then closes the load switch again. 2. The control (2) device installed in each feeder to control the busbar contact circuit breaker and load switch includes an internal ground fault direction detection relay connected to the zero-phase current transformer installed in the feeder, and an internal short circuit detector connected to the current transformer;
A power distribution system according to claim 1, comprising a time-limited accident investigation device installed between these internal ground fault direction detection relays and internal short circuit detectors and a load switch installed in the feeder. Automatic control device for track switches.