JPH02183928A - Transformer station protecting system and circuit breaker - Google Patents

Abstract

PURPOSE:To re-close a sound circuit breaker side and continue the operation of a transformer station by providing intermediate current transformers on both ends of a bus bar liaison circuit breaker and detecting which side of the intermediate current transformers is the grounding point. CONSTITUTION:Intermediate current transformers(CT) 1c are provided on a main circuit conductor between multiple cutoff points CB1a and CB1b of a bus bar liaison circuit breaker CB1. When the occurrence of grounding is detected, secondary current phases of CTs of circuit breakers CB1, 5, 6, 11, 12, 21, 22 are compared with the bus bar voltage phase, and the position or the like of the CT where the grounding current is generated is judged. After all circuit breakers in the system are released, the circuit breaker on the recoverable bus bar side is turned on. Even when grounding occurs in the bus bar liaison circuit breaker CB1, on which side of CB1a and CB1b constituting the circuit breaker CB1 the grounding has occurred can be judged. The operation of a transformer station can be continued without stopping the whole system.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to protection systems for electrical substations, and more particularly.

The present invention relates to a substation protection system and circuit breaker that can improve the operation method of a substation equipped with GIS.

[Conventional technology] As conventional technology regarding substation protection system.

For example, a technique described in Japanese Unexamined Patent Publication No. 59-106807 is known. Hereinafter, an example of a substation protection system according to this kind of conventional technology will be explained with reference to the drawings.

FIG. 12a is a diagram showing a system configuration of an example of the conventional technology;
FIG. 12b is a diagram illustrating the control process. 12th
In figures a and 12b, 1 is the first bus line, 2 is the second bus line,
la, lb, 5a, 5b.

6a, 6b, lla, 12a, 21a, 22a are ground fault current detection current transformers (hereinafter simply referred to as CT), CBI, C
B5. CB6. CBII, CB12°CB 21. C.B.
22 is a circuit breaker, CB 1 a and CB 1 b are breaking points, 11 is a receiving section, 12 is a ground fault detection section, and 13 is an all circuit breaker trip command section.

As shown in Figure 12a, the substation protection system according to the prior art includes two busbars, busbars A and B, a busbar communication circuit breaker CBI that connects these two buses, and a circuit breaker for each busbar. Connected bus section circuit breaker CB5. CB6 and
Circuit breaker CB l 1 that connects each bus bar and other lines
．． CB 12. Both CB21°CB22 and the busbar communication circuit breaker CBI (CTla provided in 1tl+)
, lb, CT5a, 5b and 6a, 6b provided on both sides of the busbar section circuit breakers CBS, CB6, and the circuit breakers CB11, CB12. CB21. C T 11 a , 12 a , provided on the busbar side of the CB 22 ,
21a and 22a. The busbar communication circuit breaker CBI has a plurality of breaking points CB1.
a, CB1b.

In a substation equipped with the above-mentioned protection system, when a ground fault occurs in any of the circuit breakers, a ground fault current is detected by each CT, and the ground fault current detection signal is as shown in Fig. 12b. The signal is received by the receiving section 11 and provided to the ground fault detection/judgment section 12 . Based on this signal, the ground fault detection/judgment section 12 detects that a ground fault has occurred, gives an instruction to the all circuit breaker tripping command section 13, and then trips all the circuit breakers. let

By the way, in the conventional control process shown in FIG. 12b, when a ground fault occurs in a circuit breaker sandwiched between two CTs, that circuit breaker and all circuit breakers connected to that circuit breaker are opened. After all circuit breakers have been tripped,
Other circuit breakers are reclosed. But now, C
Between Tla and lb, that is, busbar communication circuit breaker CB1
If a ground fault occurs somewhere in the circuit, all circuit breakers connected to both sides of the circuit will be opened, and in the case of the example shown in Figure 12a, all circuit breakers shown in Figure 1 are controlled to open. It turns out. In this manner, the system shown in FIG. 12a eliminates faults, but as a result of this fault removal, the substation is completely shut down, resulting in a wide range of power outages.

The above-mentioned conventional technology causes a widespread power outage when a ground fault occurs in the busbar communication circuit breaker CBI, and as a conventional technology to prevent such a widespread power outage,
(1) Operate with the busbar communication circuit breaker open at all times, (2)
) There are methods such as installing two busbar connecting circuit breakers in series, and (3) setting the insulation margin of the busbar connecting circuit breaker to be high.

However, in the conventional technique (1) above, there is no point in installing a busbar communication circuit breaker, and it cannot be said to be operationally preferable.In addition, in the conventional technique (3) above, the size of the circuit breaker becomes large,
It is inferior in economic efficiency and space utilization.

Furthermore, in the prior art (2), two circuit breakers are connected in series, which increases the length and installation area.

FIG. 11 is an actual layout diagram according to the prior art of (2) above, and in the figure, CB l-1,00, CB 1-200
is the busbar connection circuit breaker.

In FIG. 11, the busbar communication circuit breaker is circuit breaker CI3.
1-1. Since the OO and CBI-200 are connected and arranged in series, the length of the substation equipment (L2) shown in the diagram becomes longer by about 10 m by the amount of the circuit breaker CBI-200, and the installation area increases. It ends up.

[Problems to be Solved by the Invention] As described above, the conventional technology in which CTs are arranged only on both sides of the m-line communication circuit breaker shown in Figure 1.2a above has a problem in that the ground fault occurs in the busbar communication circuit breaker. No consideration was given to preventing the power outage from spreading over a wider area in the event of a power outage, and all substations were shut down.
This has the problem that power supply failures are likely to occur.

In addition, the conventional technology described in (2) and (3) above, which can reduce the range of power outages, has the problem that the substation space is determined by the size of the busbar connection circuit breaker, which increases the installation space. have.

The purpose of the present invention is to solve the problems of the prior art mentioned above,
To provide a substation protection system that localizes the range of a power outage, makes it possible to minimize the occurrence of supply failures due to a power outage, and does not require a large substation space, and a circuit breaker used therefor.

[Means for Solving the Problems] According to the present invention, the object is to provide a main circuit current-carrying portion between a plurality of breaking points of a busbar communication circuit breaker At least one intermediate CT is arranged so as to intersect the ground fault point, so that it is possible to detect where the ground fault point is between the plurality of interrupting points, that is, on which side of the intermediate CT This is achieved by re-closing the circuit breaker connected to the busbar connected to the side, allowing the substation to continue operating.

Furthermore, the above object is to insulate the tanks constituting the busbar communication circuit breaker in the center, couple the CT to the ground wire connected to the plurality of electrically divided tanks, and output the output signal of the CT. By detecting this, the healthy breaking point is determined based on which of the divided tanks the ground fault occurred in, and the circuit breaker connected to the bus bar connected to the healthy breaking point side is reclosed. This is achieved by allowing the substation to continue operating.

[Operation: By providing a CT in the main current-carrying section between multiple breaking points of a circuit breaker having multiple breaking points, or by providing a CT in each of the grounding wires connected to an electrically isolated tank.
By providing T, it becomes possible to identify which of the multiple breaking points in the circuit breaker is sound, and using this healthy breaking point, the operation of the substation can be stopped to cause a total power outage. It is possible to continue without interruption.

[Embodiment 1] Hereinafter, one embodiment of the substation protection system according to the present invention will be explained in detail with reference to the drawings.

FIG. 1a is a diagram showing a system configuration of an embodiment of the present invention,
FIG. 1b is a diagram explaining the control process, FIG. 2 is a diagram showing the configuration of the busbar communication circuit breaker, FIG. 3(a) is a diagram showing the detailed configuration between multiple breaking points, FIG. (b) is shown in Figure 3 (a)
) is a sectional view taken along line A-A. In Figures 1a to 3, ↓C is the intermediate CT.

3 is a tank, 4 is an insulating spacer, 5 is a work box, 6 is a main circuit conductor, 7 is a gas, 8 is an insulating rod, 14 is a ground fault detection section, 15 is a position detection section, 16 is a voltage phase measurement section, 17 18 is a judgment section, 18 is a road point judgment section, and 19 is a specific circuit breaker closing command section.

The system according to an embodiment of the present invention shown in FIG. This differs from the prior art described with reference to FIG. 12a in that one intermediate CT1c is provided, but the structure is otherwise similar to the prior art.

An embodiment of the present invention is thus configured such that the busbar communication circuit breaker C
Intermediate C between multiple cutoff points CB1a and CB1b of BI-
By providing a T and monitoring ground fault signals from this intermediate CT1c and the CTs provided on both sides of all circuit breakers in the system, if a ground fault occurs in the busbar communication circuit breaker CBI,
The ground fault occurred at multiple breaking points Cl3 in the busbar communication circuit breaker.
It is possible to detect on which side of 1a and CBlb the occurrence has occurred, and based on the result, it is possible to operate the system on the busbar side connected to the cutoff point on the healthy side. This control process will be explained below with reference to FIG. 1b.

In FIG. 1b, the receiving section 11 receives CT multiplied signals from all other CTs including the intermediate CT 1c shown in FIG. 1a, and provides the received signals to the ground fault detection section 14 and the position detection section 15. Further, the voltage phase measuring section 16 measures the phase of the bus m voltage.

The ground fault detection unit 14 detects whether the detected current from each CT exceeds a preset current, thereby detecting the occurrence of a ground fault. The determining unit 17 determines the secondary current phase of each CT from the position detecting unit 15 and the mother #! from the voltage phase measuring unit 16. By comparing the voltage phases, the CT position where the ground fault current has occurred is determined. The ground fault point determination unit 18 receives the signals from the ground fault detection unit 14 and the determination unit 13, determines the ground fault point, that is, between which two CTs the ground fault has occurred, and determines whether all circuit breakers are exceptions. Instructs the command unit 13 to trip all circuit breakers in the system. After that, this judgment unit 1
8. Based on the signal of 17, the specified circuit breaker closing command unit 19
In this case, the circuit breaker on the bus side that can be recovered is closed.

By performing the above-mentioned control processing, even if a ground fault occurs in the bus-bar communication circuit breaker CBI, the ground fault will be detected at the breaking point CB1a that constitutes the bus-bar communication circuit breaker CBI.
, it becomes possible to determine on which side of CB1b the occurrence occurred. Therefore, the specific circuit breaker closing command unit 19 issues a closing command to the circuit breaker connected to the bus bar connected to the healthy breaking point side, thereby preventing a total power outage in the system from occurring at the substation. can be operated.

Next, the configuration of the busbar communication circuit breaker used in the present invention will be explained with reference to FIGS. 2 and 3.

As shown in FIG. 2, the busbar communication circuit breaker CDI is composed of two breaking points CBI a and CBI b arranged in a tank 3 formed between two insulating spacers 4. Insulating gas 7 is sealed inside 3,
An operation box 5 is provided outside the tank 3. As shown in FIG. 3(a), an insulated operating rod 8 is provided between the two breaking points CB1a and CB1'b, and the circuit breaker CBI can be operated via this operating rod 8. It is actuated by the operation power source provided in the box 5, and the closing and shutting operations are performed.

Two breaking points CBla and C provided in the tank 3
Blb are connected by a main circuit conductor 6, and as shown in FIGS. 3(a) and 3(b), an intermediate CT1c is connected to the main circuit conductor 6 so as to intersect with the entire main circuit conductor 6. It is provided. In the example shown in FIG. 3, one intermediate C
Although only T is shown, two cutoff points CB1a, CB
One piece may be provided on each side closer to lb.

FIG. 4 is a diagram showing another configuration of the busbar communication circuit breaker CBI, which uses optical CT. In Figure 4, 2
00 and 201 are optical transmitting and receiving ends, 202 and 203 are optical transmission lines, and 204 is an optical fiber.

The busbar communication circuit breaker CBI shown in FIG. 4 is configured with an optical CT on the main circuit conductor between two breaking points, and optical transmitting/receiving ends 200 and 201 are provided on the tank 3 and the optical CT. The light transmitted via the optical fiber 204 is input to the optical CT via the spatial optical transmission line 2o2 in the tank 3,
The configuration is such that output light from the optical CT is sent to an optical fiber 204 via a spatial optical transmission line 203.

FIGS. 5(a) and 5(b) are diagrams showing still another configuration of the bus bar contact circuit breaker CBI, which is a smaller version of CT' 1 c. In FIG. 5, 6' is a bypass conductor, and other symbols are the same as in FIG. 3.

The circuit breaker shown in Fig. 5 has a bypass conductor 6' provided in a part of the main circuit conductor 6 that connects two breaking points, and a CTlc provided on this bypass conductor 6' to reduce the size of the CTlc. It is. CT1c detects ground fault current, and accurately detects the current flowing through the main circuit conductor 6 by 21t! Since it is not intended to be determined, the ratio between the current flowing through the bypass conductor 6' and the current flowing through the main circuit conductor 6 does not have to be strictly determined.

FIG. 6 is a diagram showing still another configuration of the 1u line communication circuit breaker CB1, and the reference numerals in the figure are the same as those in FIG. 2.

The circuit breaker shown in FIG. 6 has an intermediate C']'1c.

Two breaking points CB1a, CB1. It is arranged on the ground side between b, that is, on the inside of the tank 3,
In this example, two CTlcs are provided.

A system according to an embodiment of the present invention in which the circuit breakers having the configurations shown in FIGS. 2 to 6 are used as busbar communication circuit breakers in the system shown in FIG. 1 includes CTla, lb, 5a,
5b, 6a, 6b, lla.

12a, 21a, 22a and the newly installed C T 1 a in the circuit breaker CHI, it is possible to detect at which point in the system a ground fault has occurred.

For example, CT 1 c and Cr of busbar communication circuit breaker CBI
3. If a ground fault YP1 occurs between the circuit breaker CBI and the circuit breaker CBI, the system according to the embodiment of the present invention can detect that the breaking point CB1b of the circuit breaker CBI is healthy.
BI, CBLI, CB12°CB21. CB22. C.B.
5. After tripping CB6 once, circuit breaker CB21. CB2
2. By re-closing the CB6, the operation of the system connected to the second bus 2 can be continued. In addition, in this example,
It is possible that one of the breaking points CB1a of the busbar communication circuit breaker CBI has an insulation short circuit, but the busbar communication circuit breaker C
BI has sufficient ground pressure resistance if only one breaking point is sound.

FIG. 7 is a diagram showing still another configuration of the busbar communication circuit breaker CBI. In FIG. 7, 9 is an insulating part, 10',
10' is CT, 20' and 20'' are grounding wires, and other symbols are the same as in FIG. 2.

The circuit breaker shown in FIG.
CT10', 1.
0' is provided.

In this example, if a ground fault occurs in the divided tank on the right side in FIG. The system according to an embodiment of the present invention is capable of locating the ground fault point, and as described above, the system recloses the circuit breaker connected to the bus bar that is connected to the healthy breaking point side. can continue to operate.

The busbar communication circuit breaker used in the embodiment of the present invention described above is as follows:
Although the present invention has two breaking points, the present invention can also be applied to a busbar communication circuit breaker having four breaking points.

FIG. 8 is a diagram showing the configuration of a circuit breaker having four breaking points. In FIG. 8, CBin and CBld are cutoff points, and other symbols are the same as in FIG. 2.

The circuit breaker shown in FIG. 8 has four breaking points CB1a.

It is configured with CBlb, CBlc, and CBld, and has cut-off points CB 1 a, CB , 1. b and the breaking point CBL
c.

An intermediate CTlc is provided on the inner surface of the tank 3 to determine which side from the CBld is healthy.

When the circuit breaker in this example is used as a busbar communication circuit breaker,
It is possible to operate a substation in the same way as described above for ultra-high voltages.

FIG. 9 is a diagram showing another configuration of a circuit breaker having four breaking points. In FIG. 9, 10 is an insulating spacer,
Other symbols are the same as in FIG. 8.

The circuit breaker shown in Figure 9 is designed with accident response in mind.

The gas compartments are divided by Ml spacers 10 and provided with two cut-off points in each gas compartment.

c' in the vicinity of the insulating spacer 10 of each gas compartment.
It is configured by changing r t c.

A system according to an embodiment of the present invention, in which a circuit breaker having the configuration shown in FIG. 9 is used as a busbar communication circuit breaker CBI, drains the gas in the gas compartment on the side that has caused a failure, performs repairs, and
It becomes possible to perform replacements, etc., shorten recovery time in the event of an accident, and improve operational flexibility.

FIG. 10 is a layout diagram when a circuit breaker having two breaking points is used for busbar communication.

Since there is no need to change the dimensions of the circuit breaker with multiple breaking points used in the present invention even if a CT is installed inside it, the circuit breaker with multiple breaking points used in the present invention can be installed in the same way as in the case of the prior art, as shown in FIG. Substations can be configured based on area. According to the above-described embodiment of the present invention, it is possible to limit the location where a ground fault occurs by separating a plurality of breaking points in one circuit breaker, and to limit the location where a ground fault occurs. By single-phase recirculation of the power supply, the power outage range can be minimized.

The embodiment of the present invention described above has an intermediate C in the busbar communication circuit breaker.
However, in the present invention, an intermediate CT may be provided in the bus section circuit breaker, and the same effect can be achieved.

[Effects of the Invention] As explained above, according to the present invention, it is possible to easily detect the point where a ground fault has occurred, thereby limiting the range of power outages at substations from the conventional total outage to less than half the range. It is possible to minimize power supply failures. Furthermore, according to the present invention, it is possible to achieve the above-mentioned effects while keeping the installation area of the circuit breaker the same as in the conventional case, and when the same effects as the present invention can be obtained using the conventional technology. The installation area can be reduced compared to the previous model.

[Brief explanation of the drawing]

FIG. 1a is a diagram showing a system configuration of an embodiment of the present invention,
FIG. 1b is a diagram explaining the control process, FIG. 2 is a diagram showing the configuration of the busbar communication circuit breaker, FIGS. 3(a) and (b) are diagrams showing the details, and FIGS. figure. Figures 6, 7, 8, and 9 are diagrams showing other configuration examples of the busbar communication circuit breaker, respectively, Figure 10 is a diagram showing the arrangement of the circuit breaker, and Figure 11 is based on the prior art. FIG. 12a is a diagram showing an example of the arrangement of circuit breakers, FIG. 12a is a diagram showing a system configuration of an example of the prior art, and FIG. 12b is a diagram explaining the control process. 1...A bus line, 2...A bus line, 3...
... Tank, 4.10 ... Insulation spacer,
5...Operation box, 6...Main circuit conductor, 6
'...Bypass conductor, 7...Insulating gas, 8...Insulated operating rod, 9...M! ,
'Rc section, 11... Receiving section, 12.14...
...Ground fault detection unit, 13...All circuit breaker exception command unit, 15...Position detection unit, 16...
Voltage phase measurement unit, 17...determination unit. 18... Ground fault point determination section, 20', 20'.
...Ground wire, 10'10', la, lb
, lc, 5a. 5b, 6a, 6c, lla, 12a, 21a. 22a...Current transformer (CT) for ground fault current detection, C
D.I. CBS, CD6. CBII, CB12. CB21゜CB
22 ... Circuit breaker, CB 1 a, CB 1 b,
CB 1 c. CBld...Block point. 1st σ Figure 1, A bus line 2, O bus line CB1. Busbar communication circuit breaker CB5. C86, Ta&! Intermediate divider lc, Intermediate dual flow device Fig. 1b Fig. 5 (a) (b) Bypass conductor Fig. 2 Fig. 3 Fig. 12a Fig. 1σ Ladder ra cbt C,, BID O

Claims (1)

[Scope of Claims] 1. A circuit breaker having a plurality of breaking points is used as a busbar communication circuit breaker or a busbar division circuit breaker, and a current transformer for detecting the main circuit current is provided at both ends of the circuit breaker. In the substation system, the circuit breaker having multiple breaking points is configured to include at least one intermediate current transformer that detects the main circuit current flowing through the main circuit conductor between the multiple breaking points, and At this time, the current transformer provided at both ends of the circuit breaker and the front intermediate current transformer determine the healthy breaking point of the multiple breaking points, and reclose the circuit breaker connected to the healthy breaking point. A substation protection system characterized by: 2. The substation protection system according to claim 1, wherein the intermediate current transformer is provided on a bypass conductor provided in the main circuit conductor. 3. The substation protection system according to claim 1, wherein the intermediate current transformer is an optical current transformer. 4. The substation protection system according to claim 1, wherein the intermediate current transformer is provided on the inner surface of a tank in which a circuit breaker is installed. 5. Instead of the intermediate current transformer, the tank of the circuit breaker having multiple breaking points is electrically divided by an insulating material near the middle of the multiple breaking points, and a grounding wire is connected to each divided tank. 2. The substation protection system according to claim 1, further comprising: a ground fault detection current transformer for each of the ground wires. 6. A circuit breaker comprising a plurality of breaking points, a main circuit conductor that connects these breaking points, and an intermediate current transformer that detects the current of the main circuit conductor. 7. The circuit breaker according to claim 6, wherein the intermediate current transformer is provided on the main circuit conductor. 8. The circuit breaker according to claim 6, wherein the intermediate current transformer is provided on a bypass conductor provided on the main circuit conductor. 9. The circuit breaker according to claim 6, wherein the intermediate current transformer is provided on the inner surface of a grounded tank. 10. The circuit breaker according to claim 6, wherein the intermediate current transformer is an optical current transformer.