JPH02114817A - Relay operable with malfunction of circuit breaker - Google Patents

Abstract

PURPOSE:To simplify the circuitry by arranging an overcurrent relay for coping with malfunction of a circuit breaker having all lines connected in parallel at the output side of the secondary suppression circuit in a bus protection overcurrent input device in parallel with the input of a bus protection relay. CONSTITUTION:A bus 1 is connected through circuit breakers 2, 3... and CTs 4, 5... with circuits Li(i=1, 2...) to be protected. Secondaries of the CTs 4, 5... are connected with bus protection input devices 6, 7... AC side outputs from the bus protection input devices 6, 7... are connected differentially then they are fed to a bus protection relay 8. DC outputs from the bus protection input devices 6, 7... are connected together with an overcurrent relay 9 coping with malfunction of a single circuit breaker and also connected with the bus protection relay 8. When the bus protection relay does not function against overload Li, the overcurrent relay coping with malfunction of circuit breaker functions to trip the circuit breaker for the load Li. By such arrangement, countermeasure against malfunction of circuit breaker can be taken through a simple circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a relay device for preventing breaker malfunction provided for system protection.

[Conventional technology]

Generally, an overcurrent relay 51Ry connected to a power transmission line is provided for each line and is used for detecting breaker inoperation.

Figure 5 is, for example, literature, Mitsubishi branch axis VOL45, NO19.
, P1138-P1139, is a power system diagram of a power transmission line for explaining a conventional breaker malfunction countermeasure shown in September 1970. 3 is an example of the secondary circuit of the input device of the bus protection relay that detects overcurrent in the power system of the power transmission line and protects the bus shown in FIG. is the breaker connected to the busbar, 4.5 is the current transformer,
6.7 is a bus protection input device, 8 is a bus protection relay, 9
, 10 is an overcurrent relay 51F for preventing breaker malfunction.

In addition, Fig. 4 is an interlock block diagram of the breaker malfunction countermeasure device CBF, etc., where 21.22n is the power transmission line protection device, 23 is the breaker malfunction countermeasure device CBF, 24.25
is a transformer protection device, and 26 is another power transmission line protection device LP2.
27A, 28A, and 29D are circuit breakers connected to the bus 1.

In addition, in Fig. 5, 1 is a bus bar, 3233 is a power transmission line,
34.35 is a transformer, 29A to 29D are power line breakers, 36 is a power line fault location, 27A, 27B and 28A,
28B is a transformer breaker.

Next, the operation will be explained. First, normally, when a short circuit or a ground fault occurs in a power transmission line of an electric power system, a circuit breaker is operated by the operation of a protective relay device to eliminate the fault. However, if there is a malfunction in the protective relay device or the breaker and the disconnection operation is not performed, a separate device, that is, backup protection, is required to perform the disconnection operation. Generally speaking, there are remote backup protection, self-terminal relay backup protection, and measures against breaker inoperation as means for causing such interruption.

First, the operation of the breaker malfunction countermeasure shown in FIG. 5 will be explained. First, when a power line accident occurs at the power line accident location 36 of the power transmission line 33, the power line protection device 21 that protects the power line 33 determines that it is an internal accident and immediately operates.

Then, the power transmission line breakers 29A and 29B are cut off. However, even if the breaker 29A operates normally, the accident cannot be eliminated if the breaker 29B does not operate. In such a case, the circuit breakers 27A, 28A, 29 connected to the bus bar 1 are activated by the backup operation of the circuit breaker malfunction countermeasure device 23 shown in FIG.
D is cut off to eliminate the accident.

As shown in FIG. 4, the breaker malfunction countermeasure device 23 is an overcurrent relay 51F for breaker malfunction that operates when the opening/closing conditions of the circuit breaker CBO3, 29B and a current exceeding a predetermined current flow.

9. When the parallel condition in 10 and the series condition of the transmission line protection relay LP operation continue for a certain period of time or more, the breaker malfunction is detected and each transformer protection device 24.25 and the transmission line protection device 21 to 22n are activated. Activate and finally transformer breaker 2
7A.

28A and power transmission line breaker 29D are cut off.

The above-mentioned breaker malfunction countermeasure device 23 is connected to each power transmission line protection device 2.
1 to 22n and the transformer protection device 2425, respectively.

Figure 3 is a secondary circuit diagram of a current transformer in a power system.
0 and input to the bus protection input devices 6 and 7.

The secondary circuit of the bus protection input device 6.7 is connected differentially to the bus protection relay 8. The overcurrent relays 9 and 10 for preventing breaker malfunction operate when they detect that a current exceeding a predetermined value flows through the current transformer 4.5 of each line, and operate as shown in Figure 4, the overcurrent relay 9.10. A breaker malfunction is detected using the AND condition.

[Problem that the invention seeks to solve]

Conventional breaker malfunction countermeasure relay devices are configured as described above, so overcurrent relays for breaker malfunction countermeasures are provided for each transmission line protection device and transformer protection device, and the same breaker malfunction countermeasure relay device is configured as described above. A power line protection system has to be provided with a device to prevent malfunction for each protection device, making the power transmission line protection system complicated and expensive.

This invention was made to solve the above-mentioned problem, and all circuits are connected in parallel on the output side of the secondary side suppression circuit of the input device for bus bar protection. Connect to the final circuit end. By installing it in parallel with the input line to the busbar protection relay, the overcurrent relay for preventing breaker malfunction can be replaced with one, improving reliability and providing an inexpensive measure for preventing breaker malfunction. The purpose is to obtain a relay device.

(Means for Solving the Problems) A relay device for preventing breaker malfunction according to the present invention is provided with one overcurrent device for preventing breaker malfunction on the secondary side of a bus protection input device. .

[Effect]

The breaker malfunction countermeasure relay device according to the present invention is provided with one overcurrent relay for breaker malfunction countermeasure, and is connected in parallel with the secondary side suppression circuit output terminals of a plurality of bus bar protection input devices as input signals thereof. It is designed to be input into the circuit breaker inoperation countermeasure device.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same parts as in FIG. 3 are designated by the same reference numerals. Reference numeral 9 designates an overcurrent relay for preventing the breaker from operating. Further, FIG. 2 is an interlock block diagram of the breaker malfunction countermeasure device 23.

Next, the operation shown in FIG. 1 will be explained. First, current transformer 4.
The line overcurrent signal detected by 5 is input to the primary side of a bus protection input device 6.7, and its secondary side is differentially connected and connected to a bus protection relay 8. The overcurrent relay 9 for preventing breaker malfunction is connected to the busbar protection input device 6, 7-2.
It is connected to the suppression circuit on the next side, and inputs the internal large current of each line current, and when the current flows in a line with a predetermined value or more, it is detected by the current transformers 4 and 5 and activated, and the transmission line protection device 21
The circuit breaker malfunction is detected by the breaker malfunction countermeasure device 23 under the AND condition with the operation of ~22n.

As shown in FIG. 2, the circuit breaker malfunction countermeasure device 23 includes a circuit breaker malfunction countermeasure overcurrent relay 51F that operates when a current exceeding a predetermined value flows through each line based on the opening/closing conditions of the transmission line breakers CBO3 and 29B; When the parallel condition with 9 and the series condition of operation of the power transmission line protection devices 21 to 22n continue for a predetermined time or more, a breaker malfunction is detected and the transformer protection device 24 is activated.
．． 25 and each breaker 27A from the power transmission line protection device 26,
Cut off 28A and 29D.

By providing one overcurrent relay 51F, 9 for preventing breaker malfunction, each transformer protection device 24, 25 and transmission line protection device 26 can be equipped with an overcurrent relay for preventing breaker malfunction. There is no need to provide current relays 51F and 9.

[Effects of the Invention] As described above, according to the present invention, two busbar protection input devices are provided.
Install one overcurrent relay in the next-side suppression circuit to prevent breaker malfunction.
Since they are commonly provided, the device is not only inexpensive, but also has the effect of simplifying the breaker malfunction countermeasure device.

[Brief explanation of the drawing]

Figure 1 is a secondary circuit diagram of the power system current transformer of the present invention;
The figure is an interlock diagram of the breaker malfunction countermeasure device of the present invention, FIG. 3 is a secondary circuit diagram of a conventional power system current transformer, and FIG. 4 is an interlock diagram of a conventional breaker malfunction countermeasure device. FIG. 5 is a power system diagram for explaining measures against breaker malfunction. 1 is the bus bar, 2.3 is the breaker, 4.5 is the current transformer, 6.7
is a busbar protection input device, 8 is a busbar protection relay, 9 is an overcurrent relay for preventing breaker malfunction, 23 is a breaker malfunction/countermeasure device, 24° 25 is a transformer protection device, 21 to 22
n, 26 is a power transmission line protection device. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A bus protection input device that detects the current of each line connected to the bus using a current transformer and inputs the detected signal, and a bus protection input device that detects the current value of the current value input to the bus protection input device in all circuits. A busbar protection relay that receives the maximum amount of suppression as an input, an overcurrent relay that uses the suppression amount as an input to prevent the inoperation of the breaker, and an overcurrent relay that takes the breaker out of operation as an input. A shear breaker that operates when it detects that the shear breaker is inoperable and that the shear breaker is not completed within a predetermined time from the time when the shear breaker is given a shear breaker command. A relay device that prevents disconnection from working and is equipped with a countermeasure device.