JPH074047B2 - Substation fault section detection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is to automatically detect a faulty section when a ground fault or a short-circuit accident occurs inside a power transmission substation or a distribution substation. The present invention relates to a fault section detection system for a substation capable of

(Prior Art) In a power transmission substation or a distribution substation, a plurality of power supply lines or transformer banks (hereinafter referred to as banks) and a plurality of load lines are connected to a single or a plurality of buses via a disconnector. It is connected. And since CT is attached to each power line or bank and load line, an accident that occurred outside the substation can be immediately known by those CTs, and other parts can be separated by cutting off the part where the accident occurred. Power can be continued to the part of. But the bus of the substation,
If an accident occurs inside the substation such as the bank side doll part (power line or the connection part between the bank and the bus bar) and the track side doll part (connection part between the load line and the bus bar), the failure section is It was not easy to know, and all the railroads had to be cut off until the worker went to the site and found the fault. Especially when many power supply lines or banks are connected on the bus bar, current will flow from the many power supply lines or banks toward the failure point, so simply install a CT to detect the fault current. However, it was impossible to find a failure point.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional drawbacks and immediately detects the fault section from the outside even when a ground fault accident occurs in the substation, and separates the fault section. It has been completed for the purpose of a fault section detection system for a substation that enables continuous power transmission to a healthy section.

(Means for Solving the Problem) The present invention provides a busbar disconnector and an optical CT respectively on the busbars between banks of a substation in which a plurality of power supply lines and a plurality of banks are connected to a single busbar. A relay that can detect the direction of the current from the output of the optical CT is installed, and the optical CT can be installed when an accident occurs.
The first invention is characterized in that the fault current is detected by the method, the direction in which the fault current flows is determined by the relay from the current, and the result is input to the arithmetic unit to automatically detect the section in which the fault has occurred. , And a busbar disconnector and an optical CT are attached to each bank-side doll section and each line-side doll section of a substation in which multiple banks and multiple load lines are connected to multiple busbars. A relay that can detect the direction of the fault current is installed, and when the fault occurs, the fault current is detected by the optical CT, the direction of the fault current is discriminated from the current by the relay, and the result is input to the computing unit to cause the fault. A second invention is characterized in that the section is automatically detected.

(Example) Below, this invention is demonstrated in detail by the 1st Example about a distribution substation, and the 2nd Example about a transmission substation.

FIG. 1 is a circuit diagram showing an embodiment of a distribution substation,
(1) is a single bus, (2) and (3) are this bus (1)
Is a power line connected to, and (2) is a power line 1, (3)
Will be referred to as a power line 2. Also, (4), (5),
(6) is a bank connected to the bus (1). A conventional CT is placed between each power line (2), (3) and the bus bar (1).
(7) and (8) are provided, and the current flowing through this portion can be detected and taken out. Between the banks (4), (5) and (6) on the busbar (1), the busbar disconnectors (9) and (10), the optical CTs (11) and (12), and the current direction Detectable relays (13) and (14) are attached. As the relays (13) and (14), a ground fault direction relay, a short circuit direction relay, etc. are used, and the PT at the end of the busbar (1) is used.
The direction of the current flowing through the busbar (1) can be detected with reference to the three-phase voltage levels obtained by the (transformer) (15).

Such a faulty section detection system includes a power line (2),
If an accident occurs in (3), CT (7), (8)
The fact that the abnormality can be detected immediately is the same as in the past. If a ground fault occurs at point A in Fig. 1,
A large fault current flows from both power lines (2) and (3) toward point A, as indicated by the arrow, so optical CT (11), (12)
If the direction of the fault current flowing in these parts is detected by the relays (13) and (14) from the current detected in step 3, it can be determined that a fault has occurred in the part between the busbar disconnectors (9) and (10). can do. When an accident occurs at point B on the busbar (1), the accident currents flowing through the busbar disconnectors (9) and (10) both point to the left, and when an accident occurs at point C, the accident occurs. Since both currents are directed to the right, the failure section can be automatically detected by inputting the direction of the currents into a calculator (not shown). Then, by opening the bus line disconnectors (9) and (10), the faulty section can be automatically separated and power can be transmitted to a healthy section. As a matter of course, the operator can judge if there is no relay.

Next, an embodiment of the double bus type power transmission substation shown in FIG. 2 and thereafter will be described in detail.

In Fig. 2, (21) and (22) are instep A and Oto's bus, (2
In 3), (24), (25), and (26), banks 1 to 4 and load lines are shown by symbols "i" to "i". Disconnectors (27) and (28) and CTs (29) and (30) are attached to the banks (23) to (26) and the load line connectors, respectively. In addition, each bank (23)-(26) and the load line can be connected to both the instep, Otsu's busbars (21) and (22) from the part called the doll part in the center of the busbars (21) and (22). The busbar disconnector (31),
(32) is attached, and by closing one of them and opening the other, the busbar (21) or (22) of either instep or B
And is selectively connected to. Fig. 2 shows the standard connection. The first bus (23) and the third bank (25) are supplied to the instep bus (21) and the second is to the second bus (22). Power is supplied from the fourth bank (24) and (26). The load lines of a and c are connected to the bus line of the instep (21), the load lines of b and d are connected to the bus line of the second line (22), and the same pattern is repeated three times. The bus-side disconnector (3
In addition to 1) and (32), optical CTs are installed with relays (35) and (36) that can detect the direction of the current from the current obtained. The relays (35) and (36) are the first
Is similar to that of the embodiment of FIG.
Although only one is shown, it is laid on all the dolls.

In the power transmission substation shown in FIG. 2, a normal current flows in the direction of the arrow during normal times, and power is transmitted to each of the load lines I to I. However, as shown in FIGS. 3 to 8, when an accident occurs at various positions inside the substation, the accident current flows in the direction of the accident as indicated by an arrow in accordance with the accident. That is, the third
As shown in the figure, if an accident occurs on the instep bus (21), the optical CT (33) and relay (35) of the first and third banks (23) and (25) on the bank side doll part ) Detects the upward fault current indicated by the arrow. Next, as shown in Fig. 4, when an accident occurs on the track side doll part of Ha's load line, the light from the bank side doll part of the first and third banks (23) and (25)
In addition to the CT detecting the fault current in the same direction as in Fig. 3, the optical CT (33) and relay (35) on the line side doll part of C detect the fault current in the direction indicated by the downward arrow. Next, as shown in Fig. 5, when an accident occurs in the doll section of the first bank (23),
The doll part on the bank side of the first bank (23) faces downward, and the third
An upward accident current flows in the doll part on the bank side of the bank (25). Similarly, Fig. 6 shows an accident in the doll section of the 3rd bank (25), Fig. 7 shows an accident in the Otsu busbar (22) when the instep busbar (21) is stopped, and Fig. 8 shows the same instep A. The bus bar (21) of Figure 2 shows an accident in the doll part on the track side of the load line of Ha when the bus is stopped. The direction of the fault current in each case is summarized in the table on the next page.

As described above, according to the present invention, by detecting the direction of the fault current flowing through each point, it is possible to know in which section the fault has occurred, and the output of the optical CT at each point and the output of the relay are similar to those of a microcomputer. It is possible to automatically detect the section in which an accident has occurred by inputting it to another computing unit. It is also possible to omit the relay and process everything with a microcomputer. In the embodiment, the load line C is taken up as a representative, but it goes without saying that any of the load lines I to I can be similarly detected. As described above, according to the present invention, even when an accident occurs inside a transmission substation having a double bus, the failure section is immediately detected,
By disconnecting the section, it is possible to continue power transmission to the healthy section.

The operation of the system of the present invention has been described above. Next, the specific configuration of the device will be described.

FIG. 9 is a view showing a detection system of the present invention, (40)
Is an insulator that supports the disconnector, an optical fiber (41) is embedded in the insulator, and a photocurrent sensor (42) for detecting an electric current is attached to the head of the insulator (40). . First
Figure 10 shows an enlarged view of the insulator head, with the disconnector fitting (44) and conductor (4) above the head fitting (43) of the insulator (40).
5), the contactor (46) is attached, and the photocurrent sensor (42) housed in the sensor case (47) is attached to the side surface of the conductor (45) via the insulating spacer (48). The optical fiber (4) embedded in the insulator (40)
1) Photocurrent sensor (42) through the inside of pipe (49)
Is bound to. YIG, B as the photocurrent sensor (42)
A Faraday element such as SO can be used. The first
11 and 12 show an example in which a photovoltage sensor (50) is incorporated in addition to the photocurrent sensor (42). In this case, the intermediate electrode (52) is provided inside the insulating cover (51), and the conductor (45)
And the voltage induced between the intermediate electrode (52) and BSO or LiNb ₃
An optical voltage sensor (50) consisting of a Pockel element such as O detects. The insulator (40) is an insulator in which a plurality of optical fibers are built in the center thereof and is sealed with a resin having excellent insulating properties such as silicone rubber.

Returning to FIG. 9 again, the light emitting element (54) in the detector (53) is introduced into these sensors through the optical fiber (41), and a current or voltage is received as an optical signal by the light receiving element (55). ), Is converted into an electric signal here, and enters the arithmetic unit (56). The signal from the PT (57) is also used by the calculator (56).
The direction of the fault current is discriminated by entering the internal direction disconnector (58). Then, these outputs are input to the fault point discriminator (59) and the fault section is discriminated as described above. Although FIG. 9 shows only three detection points, the actual number of detection points is large as shown in FIG.

(Effects of the Invention) As described above, the present invention is capable of immediately discriminating a failure section even when an accident occurs inside a substation and continuing power transmission to a healthy section by separating the failure section. Therefore, as a fault section detection system for substations, which has eliminated the conventional problems, it is extremely important to contribute to industrial development.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the first invention, FIGS. 2 to 8 are circuit diagrams showing an embodiment of the second invention, and FIG. 9 is a second view.
Block diagram showing the system configuration of the invention of FIG.
The figure is a partially cutaway front view of the insulator head, and FIG. 12 is a partially cutaway plan view of FIG. 11. (1): Bus bar, (2), (3): Power line, (4),
(5), (6): Bank, (9) (10): Busbar disconnector,
(11), (12): Optical CT, (13), (14): Relay, (2
1), (22): Bus, (23) to (26): Bank, (3
1), (32): Bus disconnector, (33), (34): Optical CT, (3
5), (36): Relay.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuro Shinoda 4-71, Iwato-cho, Minami-ku, Nagoya-shi, Aichi (72) Inventor Toshiyuki Kawaguchi 59 in 1-chome, Goro-maru Tsutsumi, Inuyama, Aichi

Claims (2)

[Claims] 1. A busbar disconnector and an optical CT are respectively mounted on the busbars between banks of a substation in which a plurality of power supply lines and a plurality of banks are connected to a single busbar, and a current is output from an output of the optical CT. A relay that can detect the direction of
The fault current is detected by CT, the direction of the fault current is judged by the relay from the current, the result is input to the calculator, and the section where the fault occurs is automatically detected. Failure zone detection system. 2. A busbar disconnector and an optical CT are attached to each bank-side doll section and each line-side doll section of a substation in which a plurality of banks and a plurality of load lines are connected to a plurality of busbars, and an optical CT. A relay that can detect the direction of the fault current by the output of the
A fault section detection system for a substation, characterized in that the relay determines the direction of the fault current from the current and inputs the result to a computing unit to automatically detect the section in which the fault has occurred.