JPH04299016A - Reclosing system - Google Patents

Abstract

PURPOSE:To prevent the occurrence of excessive reclosing so that no trembling can be given to a system when a fault occurs in the transmission system of its own and adjacent lines while reclosing no-voltage time is confirmed by inhibiting the establishment of a reclosing liking condition and discontinuing high-speed reclosing after reclosing is abandoned. CONSTITUTION:The output of an AND circuit 12 which inputs each defective output of transmission systems of its own line and an adjacent line and the output of a linking condition discrimination circuit 10 is used as one output of an AND circuit 11. In other words, the outputs of a reclosing no-voltage timer 3 and the circuit 12 are inputted to the AND circuit 11 and the output of the circuit 11 is used as a turn-on command. When a fault occurs in the transmission system of its own line of the adjacent line and the fault continues, the input to the AND circuit 12 is discontinued through a NOT circuit on each circuit side and high-speed reclosing is discontinued after reclosing is abandoned by inhibiting a reclosing turn-on command by setting the linking condition to a non-established state even when the output of the circuit 10 exists.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention transmits and receives reclosing interconnection conditions between electrical stations facing each other on a power transmission line via a transmission device, and performs synchronized system operation based on the interconnection conditions between the own station and the opposing electrical station. This relates to a re-closing method that determines whether the circuit breaker is maintained and controls the closing of the circuit breaker.

0002

[Prior Art] In general, power transmission line protection devices are designed to improve system stability and speed up automatic recovery after fault removal.
A reclosing function is added. As is well known, reclosing is the most common cause of power line failures, as the majority of transmission line failures are flash faults caused by lightning damage.
This is a function that restarts the breaker and restarts power transmission after a period of deionization during which the insulation at the fault point recovers after a fault has been cut off. The breaker is restarted on the condition that synchronized operation of the system is maintained between opposing electrical stations. In order to improve the stability of the grid, it is necessary to perform high-speed reclosing. Therefore, in the high-speed reclosing method, the breaker is not tripped when a fault is removed and power transmission continues. The system uses a method to detect the healthy phases in the system and determine whether the system is operating synchronously.

[0003] As a means of confirming the number of healthy phases at the time of fault removal, if the information is only available at the local site, a power flow detection relay is installed in each phase, and the operating conditions of the relay and the breaker and disconnector at the local site are checked. Although a method is used that detects a combination of "open" and "closed" information of a vessel, depending on the size of the power flow, it may not be possible to accurately determine the interconnection conditions. On the other hand, the circuit breaker and disconnector information is transmitted between electrical stations via transmission equipment, and the circuit breakers and disconnectors at both ends of the power station detect the closed circuit phase and determine the interconnection conditions. There is a way to do it. This method has been actively adopted in recent years as the PCM current differential protection method for power transmission line protection has progressed, and equipment information can now be easily transmitted using digital transmission lines and optical transmission methods using OPGW. .

FIG. 3 is a diagram illustrating a configuration example of a high-speed reclosing type interconnection condition confirmation circuit for a power transmission line protection device applied to a parallel two-circuit power transmission line. In the figure, the reclosing circuit is activated by a trip signal 1 of the own circuit, and the activation condition is held by a memory circuit 2. When starting the reclosing circuit, the reclosing no-voltage timer (79T1) 3 and the reclosing abandonment timer (79T2) 4 are activated.
to drive. CB/LS condition 5a of the transmitted destination end,
When a transmission failure occurs, 5b and 5c are connected to the CB/L at their own end via circuits 6a, 6b, and 6c that hold the state at the previous value.
S conditions 7a, 7b, 7c and AND conditions 8a, 8b, 8c
, and detects interconnection for each phase of its own line.

[0005] The interconnection of adjacent lines is detected for each phase using a similar circuit configuration. These adjacent line interconnection conditions 8a, 8b, 8
c is introduced, and OR conditions of own line interconnection conditions and adjacent line interconnection conditions are created using OR circuits 9a, 9b, and 9c. As for the grid connection condition, the judgment circuit 10 detects the number of grid connection phases that can maintain synchronized operation of the grid in the total of two lines, and when the grid connection condition is satisfied, the output is set to "1" and the reclosing no-voltage time timer 3 times out. Then, when the AND condition of the AND circuit 11 is satisfied, a closing command is output. Here, since the transmitted information such as the breaker and disconnector information of the opposite electric station cannot be trusted if a failure occurs in the transmission system, the previous value is held by the holding circuits 6a, 6b, and 6c shown in FIG. , information on normal conditions before the occurrence of a failure is used, or information on circuit breakers and disconnectors at the opposite electrical station is treated as open to ensure safety against the combination of different systems.

[0006]

[Problem to be Solved by the Invention] In the reclosing interconnection condition determination circuit described above, if a failure occurs in the transmission system of the own line while checking the reclosing no-voltage time, the interconnection of the own line will be cut off. The state is maintained, but if the adjacent line is healthy, interconnection conditions are established based on the adjacent line conditions, and re-closing is performed. Normally, carrier relays such as current differential relays lock the relay output to prevent malfunction when there is a failure in the transmission system, so if the failure in the transmission system that occurred during the reclosing no-voltage time check continues In the event of a permanent failure, the final cutoff should normally be made immediately after re-closing the circuit, but due to the relay lock, the circuit cannot be cut off by its own device, which is undesirable as there is a possibility that a large disturbance may be caused to the system again. The present invention has been made to solve the above-mentioned problems, and in a reclosing method that transmits information on the circuit breaker and disconnector of the opposite electric station to determine interconnection conditions, it is necessary to It is an object of the present invention to provide a reclosing method that prevents excessive reclosing and does not cause excessive fluctuations to the system when a failure occurs in the transmission system.

[0007]

[Means and effects for solving the problems] In the present invention, in a reclosing method that transmits breaker and disconnector information of the opposite electric station and determines interconnection conditions, the self-circuit and If a failure occurs in the transmission system of the adjacent line,
It is configured to prevent the reclosing interconnection condition from being satisfied and to stop high-speed reclosing after the reclosing abandonment time. As a result, if a failure in the transmission system continues and the operation of the carrier relay is not guaranteed, excessive reclosing can be prevented, and a reclosing method that does not cause excessive fluctuations to the system can be obtained.

[0008]

[Embodiment] An embodiment will be described below with reference to the drawings. Figure 1
3 is a block diagram of an embodiment for explaining a reclosing system interconnection condition determination circuit according to the present invention, and the same parts as those in FIG. In FIG. 1, reference numeral 12 denotes an AND circuit which takes as input conditions the respective faulty outputs of the own line and adjacent line transmission system and the output of the interconnection condition determination circuit, and its AND output serves as one input of the AND circuit 11. That is, the AND circuit 11 includes a reclose circuit no-voltage time timer 3.
and the output of the AND circuit 12 are input, and the output is used as a closing command. The other configurations are the same as in FIG. 3.

Next, the operation will be explained. Since the operation in the normal state is the same as that in the case of FIG. 3, the explanation will be omitted, and only the case of a transmission system failure will be explained. If a failure occurs in the transmission system of the own line or the adjacent line during the reclosing no-voltage time and continues, the input to the AND circuit 12 is cut off via the NOT circuit on each line side. Therefore, even if there is an output from the grid interconnection condition determination circuit 10 (even if the grid interconnection is maintained), the grid interconnection condition is controlled to be unfulfilled to prevent the output of the reclosing command, and after the reclosing abandonment time, Abort high-speed reclosing. According to the above embodiment, if the power transmission line protection relay cannot be shut off again in the event of a permanent fault in the grid due to continued transmission failure, the re-closing is stopped to avoid disturbing the grid.

FIG. 2 is a block diagram of another embodiment, and the same parts as those in FIG. 3 are denoted by the same reference numerals and the explanation thereof will be omitted. In this embodiment, a transmission failure of the own line or an adjacent line is added as an input condition to the interconnection condition determination circuit, and the output of the interconnection condition determination circuit is derived only when there is no transmission failure. Therefore, the AND circuits 13a, 13b, 13c disable the interconnection of the outputs of the OR circuits 9a, 9b, 9c when there is a transmission failure in the own line or the adjacent line. The effects of this embodiment are similar to those of the above embodiment. Further, in the above embodiment, an example in which the system has a two-terminal configuration has been explained, but the system is not limited to this, and can be applied even in a case of three or more terminals, and the same applies to the case of one-line operation. It is clear that it has a significant effect.

[0011]

[Effects of the Invention] As explained above, according to the present invention, a line protection device using a carrier relay employs a method of detecting and determining whether a breaker at both terminals and a disconnector are "on" as a re-closing interconnection condition. In this case, when a transmission failure occurs during the reclosing no-voltage period, the line is prevented from reclosing, thereby preventing excessive oscillations that would be caused to the grid due to reinsertion and re-cutting in the event of a permanent line fault. can.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment illustrating a reclosing method according to the present invention.

FIG. 2 is a block diagram of another embodiment.

FIG. 3 is a block diagram illustrating a conventional reclosing method.

[Explanation of symbols]

1 Trip signal 2 Memory circuit 3 Reclosing no-voltage timer 4 Reclosing abandonment timer 5a, 5b, 5c Opposite end CB/LS conditions 6a, 6b
, 6c Previous value holding circuits 7a, 7b, 7c Self-end CB/LS conditions 8a, 8b,
8c, 11, 12, 13a, 13b, 13c AND circuit 9a, 9b, 9c OR circuit 10 Grid connection condition determination circuit

Claims (1)

[Claims] [Claim 1] Reclosing interconnection conditions are transmitted and received between electrical stations facing each other on the transmission line via a transmission device, and synchronized operation of the system is confirmed based on the interconnection conditions of the own electrical station and the opposite electrical station, and the recirculation is performed. A reclosing method characterized in that a reclosing command is blocked when a transmission failure occurs in a line for determining interconnection conditions.