JPH071982B2 - Loop protection relay system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a loop system protection relay system provided with measures against non-operation of a bridge and a circuit breaker.

B. Outline of the Invention The present invention provides a loop protection relay system with a backup protection function in the central processing unit, which is shorter than the time limit of the backup relay, and is inoperative when an accident is detected. By tripping the breaker or breaker, if the breaker or breaker or the trip circuit of the slave unit is broken, the accident spread range can be limited to a narrow range.

C. Prior Art FIG. 4 is a configuration explanatory view showing a centralized loop system protection relay system. In FIG. 4, 31A to 31D are customer busbars,
Buses 31A to 31D of each customer are connected by transmission lines 32A to 32E. The power transmission lines 32A and 32E are connected to the bus 33 on the power substation T side to form a loop power transmission system. In the figure, CB _{1 to} CB ₈ are breakers and breakers, and these breakers CB _{1 to} CB ₈ are inserted in the electric paths between the busbars 31A to 31D and the transmission lines 32A to 32E. CBA and CBB are signs and breakers inserted in the electric line that connects the transmission lines 32A and 32E and the bus 33 on the T side of the power substation. When the breakers CBA and CBB are opened, the loop system becomes a complete stop. Become. CT _{1 to} CT ₈ are current transformers, each pair of current transformers CT ₁ , CT ₂ and CT ₃ , CT _{4 and} CT ₅ , CT ₆ and C
Current information obtained at T _7, CT ₈ is inputted to the first to fourth terminals 34A~34D connected in a loop. 35 is a central processing unit, and this central processing unit 35 is the first and fourth terminal units 34A, 34
The current information of each of the terminal devices 34A to 34D, which is connected to D, is supplied to the central processing unit 35 where it is subjected to protection calculation processing. CTA,
CTB is a current transformer that causes the central processing unit 35 to input current information.

In addition, A-RY and B-RY are back-up relays.

The central processing unit 35 is apparently equivalent to that a current differential relay is arranged between each current transformer. The arrangement of this current differential relay is shown in FIG. In FIG. 5, 11
Reference numerals 19 to 19 are current differential relays, and the other parts are indicated by the same reference numerals as those in FIG.

D. Problems to be Solved by the Invention In the device configured as shown in FIG. 4, (i) it is assumed that an accident occurs on the power transmission line 32B between CT ₂ and CT ₃ . Then, in this case, even if the current information from CT ₃ and CT ₄ is correctly transmitted, the slave station device 34B associated with CB ₃
If the trip circuit is abnormal, or if CB ₃ fails and becomes inoperative, the current differential relay 13 operates and CB ₂ is tripped. However, since CB ₃ is abnormal, the accident cannot be eliminated. As a result, there is a problem in that the backup relay B-RY operates to cut or cut CBB, resulting in a power failure in the section from the transmission lines 32B to 32E.

(Ii) It is assumed that an accident occurs between CT _{5 and} CT ₆ (for example, bus 31C).

At this time, normally, CB ₄ , CB ₅ , CB ₆ and CB ₇ are tripped.
Here, tripping CB ₄ and CB ₇ is between CT ₅ and CB ₅ ,
This is because there may be an accident between CB ₆ and CT ₆ . But,
At this time, if the trip circuit of the slave station device 34B relating to CB ₄ is abnormal, or if CB ₄ does not operate and the accident cannot be eliminated,
There is a problem in that the backup relay A-RY operates to cut or cut CBA, which causes a power failure in the section from the transmission lines 32A to 32D. In addition, if the trip circuit for CB ₇ is abnormal or CB ₇ is inoperative, the backup relay B-RY operates to cut or cut CBB, and the transmission line 32C
There is a problem that there is a power failure in the section up to ~ 32E.

Even if an accident occurs on the bus 31C, if the CB ₅ and CB ₆ operate normally, the refractory movement of the CB ₇ and CB ₄ does not pose a problem. But,
In the accident between CB _{5 and} CT _5, the refractory of CB ₄ becomes a problem, and CB ₆ ~
Not responding to CB ₇ becomes a problem in an accident between CT _6.

The present invention has been made in view of the above problems, in the case of malfunction of the breaker or disconnector or failure of the trip circuit,
It is an object of the present invention to provide a loop system protection relay system capable of limiting the spread range of an accident to the minimum.

E. Means for solving the problem In the central processing unit, a backup protection function that is shorter than the time limit of the back-up relay at the power transmission end is provided, and when the accident is detected, the status information of the customer's sill or disconnector is referred to. It is characterized in that a trip signal is output to a non-operation mark or adjacent to a breaker or a breaker to cause tripping.

F. Action For example, if an accident occurs between CT _{5 and} CB _{5 in} Fig. ₄ and CB ₄ is inoperative, the backup relay would have been used in the past.
CBB operates and there is a power failure between the transmission lines 32C and 32E,
Accidents are removed by Toritsupu the CB ₃ adjacent to the CB ₄ in the present invention. Therefore, the power outage section is the transmission line 32C and the bus 3
Only 1B section.

G. Embodiment FIG. 1 is a block diagram showing an embodiment of the backup applilay in the backup protection function newly added to the central processing unit 35 in the present invention, which is installed at the power transmission end of the substation T. 2 corresponding to back-up relay A-RY and B-RY respectively
It consists of two backup relays A'-RY and B'-RY, and each relay is activated when the relay OCR 'for short circuit detection, the relay DGR' for ground fault detection, and these relays OCR 'and DGR' are activated. It includes timer T _'BS and T' and _BG, and oR gate OG to output a Taimuatsupu signal of the timer T _'BS and T' _BG fault detection signal SA, as SB.
In FIG. 1, the constituent elements in the backup relay A'-RY are designated by the reference numeral (A), and the constituent elements in B'-RY are designated by the reference numeral (B).

By the way, the backup relay A- at the power transmission end of the substation T
RY and B-RY have the same configuration as that of FIG. The structure is shown in FIG. In Figure 2, OCR, DGR,
_TBS and _TBG have the same functions as those in FIG.

Here, the timer T _'BS, T' in the present invention _BG timed is set shorter than the timer T _BS, T _BG of FIG. 2, details _{T BS (A)> T '} BS (A), T _BS (B)> T '
_BS (B), T _BS (A)> T ' _BG (A), T _BG (B)>T'
It is set to the relationship of _BG (B). Also, relays OCR, OC
R'and DGR, DGR 'are set to the same sensitivity. Therefore, when the malfunction of the breaker or the breaker occurs, the accident detection signal is first output from the back-up relay A'-RY or B'-RY in FIG.

FIG. 3 is a block diagram showing an embodiment of a trip command circuit that causes a deadlock, an adjacent circuit breaker, or a circuit breaker to trip. The trip command circuit and the back-up relay A'-RY shown in FIG. B'-RY and the back-up mechanism in the central processing unit are configured.

In FIG. 3, 11 to 19 are the current differential relays shown in FIG. 5, and the output of this relay is input to the trip sequence circuit TSQ.
Outputs a "H" level signal from the output terminals a to j in accordance with the operating states of the current differential relays 11 to 19, as shown in Table 1 below.

The output signal of this circuit TSQ is back-up relay A'-RY,
CB _{1 to} CB ₈ and C depending on the combination with the output signal of B'-RY
Logic circuit LG that determines which of BA or CBB is tripped
Entered in C. The logic circuit LGC is composed of AND gates 20 to 27 and OR gates 40 to 47.

Next, the operation will be described with a specific example.

For example, if a short circuit accident occurs in the section of the transmission line 32C, but CB ₄ is defective and the accident cannot be eliminated, it is detected by OCR (A) and OCR '(A) at the same time as the occurrence of the accident. As a result, the timers T _BS (A) and T ′ _BS (A) are started at the same time. Note that this startup state will continue as it is, if the CB ₄ is defective, the accident will not be eliminated. Where T '
_{Since BS} (A) has a shorter time limit, the back-up relay A'-RY outputs the accident detection signal first. This time,
Since the current differential relay 15 is operating, the trip sequence circuit TSQ outputs the "H" level signal from the terminals e and f, as is apparent from Table 1. This "H" level signal is input to the AND gates 23 and 24 and the OR gates 43 and 44, but since the output signal of the backup relay B'-RY is input to the AND gate 24, in the case of this accident example Condition of only AND gate 23 is satisfied, and its output signal is OR gate
It is output as a trip signal of CB ₃ via 42. T _BS
Need not to Toritsupu accidents is removed CBA before the CB ₃ is-back up-Relay A-RY operated by previously convex sufficient timed coordination between (A) and T _'BS (A). Therefore, the power failure section can be limited to only two sections of the transmission line 32C and the bus line 31B. Incidentally, accident removed inoperative cause of CB ₄ and CB ₅ when an accident has been made between the inoperative and CT ₅ to CB ₆ of CB ₄ when an accident has been made between the CT ₅ to CB ₅ If not, the trip output signal is sent to CB ₃ by the same operation. This will eliminate the accident by CB ₃ .

The above explanation is an example of continuing the accident on the CBA side, but in the case of continuing the accident on the CBB side as well, T _BS (B)> T ′ _BS (B), T
_{BG (B)> T 'BG} (B) and by connexion accident removed sufficient timed coordination adjacent breaker Toritsupu previous CBB by to have a becomes possible. Also in this case, the current differential relays 11 to 19
It is natural that a sufficient timed coordination between A and A'-RY and B'-RY is required. That is, in addition to the trip signal for the signal or breaker to be tripped originally, a trip signal for the adjacent signal or breaker is output, and the accident spread section is controlled to be only the adjacent section.

Such an operation is similarly performed even if an accident occurs in any section. As a result, the expansion of the accident spread section is minimized.

Furthermore, since the backup protection system is a double system, the reliability of the system is also improved.

H. Effect of the Invention As described above, according to the present invention, the central processing unit is provided with a backup protection function shorter than the back-up relay time limit, which is inoperative at the time of detecting an accident and adjacent to a breaker. Since it has been designed so as to cut off the breaker or breaker, if the breaker or breaker or the trip circuit of the slave station device fails, the accident spread range can be limited to a narrow range and the system There is an effect that the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a backup applilay which is a constituent element of the backup protection function of the present invention, FIG. 2 is a block diagram showing the constitution of a general backup applilay, and FIG. 3 is the present invention. FIG. 4 is a block diagram showing an embodiment of a trip command circuit which is a constituent element of a backup protection function, FIG. 4 is a circuit diagram showing a configuration of a conventional protection system system, and FIG. Is. _{CB 1 ~CB 8, CBA, CBB} ...... Shiyadan device, 31A~31D ...... busbars 3
2A to 32E ... Transmission line, A-RY, B-RY, A'-RY, B'-RY ...
… Back-up relay, 11 to 19 …… Current differential relay, TS
Q: Trip sequence circuit, LGC: Logic circuit.

Claims (1)

[Claims] 1. A plurality of slave station devices having a function of collecting and transmitting current information of a customer of a loop system and a function of receiving a transfer trip signal to trip a circuit breaker of the customer, and these slave stations. A function to receive the information transmitted from the equipment, a function to collect the current and voltage information of the substation and perform protection processing from both information, a function to trip the circuit breaker of the substation, and a transfer trip signal to each slave station device In a loop system protection relay system, which includes a central processing unit having a function of transmitting and a backup relay installed in a substation, which centrally protects a line and a bus bar in each section of a line leading to a customer, In the central processing unit, a backup protection function that is shorter than the time limit of the backup relay is provided, and a trip signal is output to the adjacent breaker of the refractory breaker when an accident is detected. ,
Loop system protection relay system characterized by tripping.