JPS6053526B2 - 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 through two trial transmissions.

Conventionally, this type of device has been used in which a non-voltage trip type sectional switch is combined with a timed accident investigation device consisting of a timed continuator and its auxiliary circuit.

For example, as shown in FIG. 1, a bus line BU connected from the power supply side in the substation 55 via a disconnector CB-M
For S, feeder or disconnector CB-1, CB-2, CB-
The first line feeder F1, the second line feeder F2, the third line feeder jF3, . . . are connected through the lines 3, .

In this case, the feeder and disconnectors CB-1, CB-2, CB-
3. Protective relay Ry-1 is installed between ... and the bus BUS.
, Ry-2, Ry-3, . . . are provided, respectively. In addition, each feeder F1, F2, F3, .
21, 522, 523, ..., and 531, 532
, 533, .
jl, 1, '21, '31,..., second section '12, e
22, e31,..., third section El3, e23, e33
, . . . are divided into n-th sections Lh,'2n,'3n, and so on. Furthermore, section switches Sll, Sl2, Sl3, ・
・,S2l,S22,S23,...,S3l,S32,
S33, ... is a time-limited accident investigation device 111, TSl2
,TSl3,...,TS2l,TS22,TS23,...
, TS3l, π12, TS33, .
Trl2L, Trl3 and 919Tr21 and 9Tr22L
9Tr23, 9r09Tr31, Tr32, Tr3
3L, . . . and voltage detection transformers TrllR, Tr are provided between the load side of the related sectional switch.
l2R, Trl3R,..., Tr2lR, Tr22R,
Tr23R,..., Tr3lR, Tr32R, Tr33
R, .
〜TS33 is operated and thereby the section switches Sll〜S
33 can be inserted and removed. The specific operation of the conventional time-limited accident investigation device configured in this manner is as follows.

For example, in FIG. 1, the third line of the first line feeder F1
Assuming that a ground fault occurs in the section El3, the protective relay Ry-1 of the feeder and disconnector CB-1 operates to open only the feeder and the disconnector CB-1. Therefore, the section switches Sll, Sl2, . . . are opened all at once because there is no voltage. However, this feeder circuit breaker CB-1 is assumed to reclose after a predetermined voltage-free time TR has elapsed. Therefore, power is transmitted to the first section 111 after a period of time TR has elapsed after no voltage has passed, and the time-limited accident investigation device TSll operates.
1, so that power is transmitted to the second section El2.

Therefore, as mentioned above, the second time detector TSL2
operates, and as a result, after T Saima, the section switch Sl
2 and transmits power to the third section. At this time, the third section E
If the cause of the fault at 13 has not yet been eliminated, the ground fault will occur again by closing the sectional switch Sl2. Since the reoccurrence time of this ground fault is within the detection time Ty, after the feeder and disconnector CB-1 are disconnected again, the sectional switch 12
becomes locked.

Next, the feeder switch CB-1 described above is reclosed to start power transmission to the healthy section El2 of the feeder F1.
When using the power distribution configuration as shown in Figure 1, there is an advantage that only the faulty feeder or disconnector is disconnected, so other healthy feeders are not affected. The drawback is that it is not expensive and the installation of a disconnector is quite expensive as a power distribution system.

In addition, although it is desirable for operation to perform multi-loop operation by inserting interconnected load switches between each feeder during normal times, this protection method is difficult and is not often implemented in reality.

Furthermore, recently, it has been desired from an economical point of view to omit the feeder or disconnector and instead provide 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 aims to provide a new automatic control device for power distribution lines that enables continuous multi-loop system operation, is economical, and can shorten accident investigation time. purpose.

Embodiments of the present invention will be described below with reference to FIGS. 2-4.

Components in the power distribution system shown in FIG. 2 that are the same as those of the power distribution system shown in FIG. Therefore, in the configuration shown in FIG.
Only the parts of the structure that are different from those shown in the figures will be explained.
As is clear from the distribution system shown in Fig. 2, in the automatic control device for the distribution line switch of the present invention, a control device CONT-M is provided at the busbar connection and disconnector CB-M in the substation SS. It is possible to insert and remove the CB-M. Further, a resistor R is connected in parallel to this cable breaker CB-M as a current limiting element, and therefore in series to the power distribution system. Furthermore, the substation bus line BUS is connected to the first load switch via load switches Sll, S2l, S3l, etc., which have load switching capabilities.
A first line feeder F1, a second line feeder F2, a third line feeder F3, . . . which are similar to those explained with reference to the drawings are connected, respectively. Load switch Sll, Sl2, Sl3・
... has control devices CONT-1, C0NT-2, C0N.
T-3,... are installed respectively, and these control devices CO
NT-1, C0NT-2, C0NT-3,...
Potential transformers TS-1, PT-2, PT-3 are provided between one input side and the substation bus BUS, and related load switches Sll, S2l, S3l, . . .
Current transformers 11, 12, 13,
... are provided, and the output sides of these current transformers are connected to the other input side of the associated control device CONT. Furthermore, in the power distribution system shown in FIG. 2, interconnection load switches are provided between each feeder to enable multiple loop operation during normal times. For this purpose, for example, the second section El of the first feeder F1
A grid-connected load switch C1 is provided between the second feeder F2 and the first section E22 of the second feeder F2, and a grid-connected load switch C1 is provided between the third section E23 of the second feeder F2 and the third section E23 of the third feeder F3. A switch C2 is provided. These load switches C1 and C2 are also equipped with time-limited accident investigation devices TSCl and TSC2, voltage detection transformers Trl, TrlR and Tr2, and T
r2R are respectively arranged. According to the present invention, in the distribution system configured and arranged in this way, the control device CONT of the present invention is operated by the current and voltage caused by the ground fault or short circuit detected by the current transformer and the potential transformer, and the related feeder is controlled. This is to operate the load switch, interconnection load switch, busbar connection or disconnector.

Next, a detailed explanation of the control invention of the present invention will be given with reference to FIG.
In FIG. 3, in order to explain the control device provided in the first line feeder F1 as an example, the suffix -1 of each reference numeral in the figure means that it is related to the first line feeder F1. The control device CONT-1 is a zero-phase current transformer Z
It operates in response to the zero-sequence current from CT-1 and the zero-sequence voltage from the grounding transformer PT-1, and issues a shear rupture command to the busbar connecting circuit breaker CB-M, and opens the circuit breaker CB-M. Grid-connected load switches C1 and C after delay by post-timer TM-1
An internal ground fault direction detection relay 52-1 issues an opening command to the current transformer CT-1, and an internal short circuit detector 51 receives current from the current transformer CT-1 and operates in exactly the same way as the internal ground fault direction detection relay 52-1. -1, both relays 52-1 and detector 51
- After the interconnection load switches Cl and C2 are opened by 1, if a ground fault or short circuit accident continues in the first line feeder F1, the time-limited accident investigation device B opens the load switch Sll.
-1. The operation of the control device of the present invention constructed as described above will be explained with reference to FIG.

As in the case of the conventional example, explanation will be given assuming that a ground fault has occurred in the third section Fl3 of the first line feeder F1. In this case, it is assumed that the interconnection load switches Cl and C2 are closed. When a ground fault current flows through the feeder F1 of the first circuit, a zero-sequence current is taken out from the zero-sequence current transformer ℃T-1, and a zero-sequence voltage is taken out from the grounding transformer T-1. Relay 52-1 operates. Grid switch Cl
, C2 are both closed and operated, the internal ground fault direction relays 52-2 and 52-3 of feeders F2 and F3 operate in the same manner as described above.

The operation of these relays 52-1, 52-2, and 52-3 issues a trip command to the shield breaker control device CONT-M.
At the same time, a command is issued to open the interconnected load switches Cl and C2 after a time period TM1 set by the timer TM-1. After the interconnection load switches Cl and C2 are opened, only the time-limited accident investigation device TS-1 of the first line feeder F1 operates and the Tx
After ``Tx'' time, an opening command is issued to load switch Sll. At the same time, the timer circuit of the time-limited accident investigation device L-1 is activated, and after Tx'' time, the timer circuit is activated to open the load switch Sll.
issue an injection command to

When time Tx has elapsed after the load switch Sll is closed, the accident investigation device 'VS12 issues a close command to the sectional switch Sl2. When a further Tx time has elapsed after closing the section switch Sl2, the accident investigation device 'VS13 issues a closing command to the section switch Sl3. If the cause of the accident still remains in the third section, the ground fault will occur again, and the load switch Sll will be disconnected by the operation of the relay 52-1 again. At this time, section switch S
Assume that l3 becomes non-voltage within Ty time after re-closing, and therefore is locked from being turned on at the time of subsequent re-closing. The load switch Sll is reclosed in the same way as described above after Tx'' time has elapsed after the re-opening, and then the section switch Sl2 is reclosed after Tx time.However, in this case, as mentioned above, the section switch Sl2 is reclosed. Sl3 maintains the open state because the feeding is locked.As described above, according to the present invention, in the case of a ground fault, only the feeder where the failure has occurred is sequentially fed (investigated).
Therefore, other healthy phases will not experience a power outage.

It is assumed that the re-closing command for the busbar contactor and disconnector CB-M is issued on the condition that the load switch Sll is closed twice.

Next, it is assumed that a short circuit accident has occurred in the third section El3 of the first circuit feeder F1, and this case will be explained with reference to FIG. 4.

The short circuit current is taken out by current transformer CT-1 and operates internal short circuit directional relay 51-1.

This issues a tripping command to the disconnection control device CONT-M.

At the same time, a command is issued to open the interconnected load switches Cl and C2 after a time period TM1 set by the timer TM-1. When the open command is issued to the interconnected load switches Cl and C2, the wire breakers CB-M are open, but in this case, the resistor R, which is a current-limiting element, is inserted in series with the distribution system. Therefore, the short circuit current is suppressed to below the ground fault current, and the interconnected load switches Cl and C2 can be opened. After opening the interconnection load switches Cl and C2, the first line feeder F1
Only the time-limited accident investigation device TS-1 operates and issues an opening command to the load switch Sll after Tx'' time.At the same time, the timer circuit of the time-limited accident investigation device L-1 is activated and the timer circuit of the time-limited accident investigation device L-1 is activated after Tx'' time. A subsequent operation is performed to issue a closing command to the load switch Sll. When Tx time elapses after the load switch Sll is closed, the accident investigation device TS12 issues a close command to the sectional switch Sl2. When a further Tx time has elapsed after the section switch Sl2 is turned on, the accident investigation device TSl3 turns on the section switch Sl3.
is injected. If the cause of the accident still remains in the third section, the short circuit will occur again, and the load switch Sll will be quickly disconnected by the operation of the relay 51-1 again.

In this case, classification. It is assumed that the switch Sl3 becomes non-voltage within the time Ty after re-closing, and therefore is locked from closing during subsequent re-closing. The load switch Sll is reclosed in the same manner as described above after a time Tx'' has elapsed after the re-opening, and furthermore, the section switch Sl2 is reclosed just after a time Tx.

However, in this case, as described above, the sectional switch Sl3 is kept open because the opening is locked. As described above, according to the present invention, even in the case of a short circuit accident, only the feeder in which the failure/failure has occurred performs progressive feeding (investigation), so other healthy phases will not experience a power outage.

In this case as well, the re-closing command for the busbar connection and disconnector CB-M shall be issued on the condition that the load switch Sll has been turned on twice. In the power distribution system of the present invention shown in FIG. 2, a resistor R is inserted in parallel with the busbar connection and disconnector CB-M, and therefore in series with the power distribution system, but the present invention is not limited to this. Of course, as shown in FIG. 5, a reactor L can be used instead of the resistor R as the current limiting element.

The operation in this case is exactly the same as that described with reference to FIG. l As described above, according to the present invention, the feeder and disconnector are omitted and the sectional switch and interconnection switch closest to the bus have the current disconnection capacity equal to the sum of the load current and the ground fault current. By using this as a so-called load switch, in the event of a ground fault, or even a short circuit, only the faulty feeder can be investigated after the load switch is disconnected and the load switch is opened. It is possible to improve the facility utilization rate and voltage of customers by operating multiple loops with the load switch closed, and it is economical, localizes the area of power outage, and shortens the power outage time. Automatic control equipment can be provided.

[Brief explanation of the drawing]

FIG. 1 is a power distribution system diagram using a conventional line switch, FIG. 2 is a power distribution system diagram having an automatic control device for a distribution line switch according to the present invention, and FIG. 3 is a block diagram showing the main parts of the device of the present invention. FIG. 4 is a time chart explaining the operation of the device of the present invention, and FIG. 5 is a power distribution system diagram showing a modification of the power distribution system having the device of the present invention. SS...Substation, CB-M...Bus bar connection and disconnection,
BUS...Substation busbar, Sll, S2l, S3l...
・Load switch, Cl, C2... Grid-connected load switch, Sl
2, Sl3, S22, S23, S32, S33... Sectional switch, 'VSl2, TSl3, TS22, 'VS23
, TS32, TS33...Timed accident investigation device, TS-
1...Timed accident investigation device, Fl, F2, F3...Feeder, R...Current limiting resistor, CONT-1~CON
T-3, C0NT-M...control device, L...current-limiting reactor, 52-1...internal ground fault direction detection relay,
51-1...Internal short circuit detector, TM-1...Timer, ZCT-1...Zero phase current transformer, PT-1...Grounding transformer, Ell~E33...Feeder division, Trll
L, TrllR-Tr33, Tr33R... voltage detection transformer.

Claims (1)

[Scope of Claims] 1. A substation bus connected to a power source via a bus link or disconnector, a current limiting element installed in parallel to the bus link or disconnector, and a load switching device having load switching capability. a plurality of feeders connected to the bus bar through the load switch and each divided into a plurality of sections by a section switch, an interconnected load switch installed between each feeder, and a plurality of feeders connected to the bus bar through the load switch, A time-limited accident investigation device is installed for each feeder that controls sequential input, and when an internal ground fault or internal short circuit is detected, the busbar contact or disconnector is tripped, and after a certain period of time, all interconnected load switches are opened. An automatic control device for a distribution line switch, comprising: a control unit having a time-limited accident investigation device that subsequently opens the load switch of only the accident feeder and then closes the load switch again; 2 The internal ground fault direction causes the control unit to receive the zero-sequence current from the zero-sequence current transformer and the zero-sequence voltage from the grounding transformer to operate the bus interconnector and disconnector, and then operate the interconnection load switch. A detection relay, an internal short-circuit detector that receives current from a current transformer, activates a bus link or disconnector, and then activates a grid-connected load switch, and a grid-connected load switch using these switches, disconnectors, and detectors. 2. The automatic control device for a distribution line switch according to claim 1, further comprising a time-limited accident investigation device that operates the load switch after the load switch is activated. 3. The automatic control device for a distribution line switch according to claim 1, characterized in that the current-limiting element arranged in parallel with the busbar link or disconnector is a resistor. 4. The automatic control device for a power distribution line switch according to claim 1, characterized in that a reactor is a current-limiting element arranged in parallel to the busbar link or disconnector.