JPH07131924A - Reclosing method for protective relay device - Google Patents

Abstract

PURPOSE:To make it possible to detect a line accident in every phase and achieve high speed multiphase reclosing even if only one phase can be provided with 'line accident absent detection', by confirming 'on' of the breaker at the advance end over a specified period of time and thus detecting 'line accident absent' before reclosing. CONSTITUTION:If failure current passes through the phase R of a transmission line and both of the advance end breaker 2a and following end breaker are opened, 'ready for reclosing' 23 is effected, and an AND circuit 24 including 'transmission line protective relay device actuation (phase R)' 22, is formed. Then 'multiphase reclosing start' 26 causes a reclosing no-voltage time timer 30 to start count. When the reclosing power supply conditions selected and set for 'following end' 28 are met at the following end and then the advance end breaker 2a is closed, an AND circuit 37 composed of 'breaker 'on'' in three phases is formed, and a following end linkage confirming timer 39 starts count. When a 'reclosing condition' 31 is also met, an AND circuit 33 is formed, and a closing command 34 is given to the following end breaker. As a result the following end breaker is closed and the ordinary condition of the system is restored.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reclosing system of a protective relay device for protecting a transmission line.

[0002]

2. Description of the Related Art Generally, most of the accidents that occur in a power transmission system are ground faults or short circuits due to arcs such as creeping surface flashovers of insulators, so it is necessary to promptly select and cut off a faulty section by a transmission line protection relay device. If it does so, there is almost no damage in the failure section, and at the same time, the arc is extinguished.
Therefore, if the protection relay device is used to interrupt the high-speed once to remove the fault and then the circuit breaker is turned on again, it is possible to continue the power transmission as it is. Therefore, the protection relay device with the reclosing function is provided. Is used. A high-speed multi-phase re-closed + medium-speed three-phase re-closed circuit is often adopted as the re-closed circuit of the transmission line protection relay device of the backbone system of an ultrahigh voltage or higher. The high-speed multi-phase reclosing is to close and reclose only the phase of the parallel two-circuit transmission line that has an accident, and to try to reclose at high speed even in the case of multiple accidents across both lines. Is. In this case, in order to secure the interconnection during disconnection, in the two-phase interconnection confirmation method, reclosing is performed under the condition of interconnection of two phases or more in total for two lines.

The purpose of this system is to maintain the stability of the system by suppressing the change of the voltage phase angle at the electrical stations at both ends by the interconnection of the sound phases even during the interruption of the accident. In the case of an accident in which the high-speed multi-phase re-closed condition is not satisfied, the medium-speed three-phase re-closed circuit is re-closed after confirming that both terminals are synchronized after the three-phase interruption for a certain time. It is a method of closing the circuit. Therefore, the medium speed three-phase reclosed circuit is inferior to the high speed multiphase reclosed circuit in terms of stability.

3 and 4 show block diagrams of a conventional transmission line system configuration and a high-speed polyphase reclosing circuit. Figure 3
Represents one of the parallel two-circuit power transmission lines, and the bus bar 4 of the first electric station and the bus bar 5 of the second electric station are the circuit breakers 2a, 2b, 2c and 3a, 3b of the respective electric stations. , 3c, and is connected to the transmission line 1. 6 and 7 indicate the back power source of each electric station. Transmission line protection relays 10 and 11 are provided at the respective terminals to take in the current of the transmission line from the variable flow paths 8 and 9 and detect an accident in the transmission line.
The transmission line protective relays 10 and 11 generally have the high-speed polyphase reclosing function described above. A conventional high-speed multiphase reclosing circuit will be described with reference to FIGS. 3 and 4. When an accident occurs at point F in FIG. 3, a fault current flows through the transmission line 1 and the current transformer 8
Transmission line protection relays 10 and 11 which are taking in fault currents via 9 and 9 operate. Thereby, the circuit breaker 2a
And shut off 3a to eliminate the accident. At this time, if the pressure condition of the circuit breaker is normal, the reclosing preparation is completed 23, and the AND circuit 24 with the transmission line protection relay operation (R phase) 22a is established and the multiphase reclosing start 26 I do. Start multiphase reclosing
The reclosed no-voltage time timer 30 is counted by 26. If both ends are turned on at the same time, set the reclosing power condition to the leading end / simultaneous 27
, The AND circuit 33 is established and the circuit breaker 2a is established when the reclosing condition 31 (for example, the interconnection of two phases or more in total of two lines) is established after the time limit of the reclosing non-voltage time timer 30.
And a closing command 34 is given to 3a. As a result, the circuit breakers 2a and 3a are turned on again to return to the normal system state.
Here, the time limit of the reclosed voltageless time timer 30 is determined in consideration of the following contents. When an accident occurs in a power transmission line, a large accident current flows and the accident phase is cut off immediately, but the surrounding air becomes ionized and becomes conductive. Due to the ionization at this accident point, the current (hereinafter referred to as the secondary arc current) due to electrostatic induction from the adjacent phase continues even after the accident current is cut off. After the surrounding air is restored to the normal insulation state, the secondary mark current at the accident point disappears. Generally, the extinction time of the secondary arc current tends to increase as the system voltage increases. Therefore, the reclosed voltage-free time of the transmission line is determined in consideration of the time until the secondary arc current at the accident point is extinguished and the surrounding air dielectric strength is restored to a value that can endure the reclosed circuit.

Next, the reclosing of the radial power supply system will be described. The rear power supply 6 side is set to the leading end side, the generator 7 side is set to the trailing end, and the reclosing power supply condition is set to "leading end / simultaneous".
27, the trailing edge is selected as the “trailing edge” 28. When an accident occurs at point F in FIG. 3, a fault current flows through the power transmission line 1, and the transmission line protection relays 10 and 11 that take in the fault current through the current transformers 8 and 9 operate. This allows circuit breaker 2
Shut off a and 3a and eliminate the accident. At this time, if the pressure condition of the circuit breaker is normal, the reclosing preparation is completed 23, and the AND circuit 24 with the transmission line protection relay operation (R phase) 22a is established and the multiphase reclosing start 26 I do. The re-closed no-voltage time timer 30 is counted by the multi-phase re-closed start 26.
The leading end is AND circuit 33 when the reclosing condition 31 (for example, the interconnection of two phases or more in total of two lines) is satisfied after the time limit of the reclosing non-voltage time timer 30 by the selection condition "leading end / simultaneous" 27. Then, the closing command 34 is given to the circuit breaker 2a.

The trailing edge is selected in the selection condition "trailing edge" 28,
When the circuit breaker 2a at the leading end is turned on, the line voltage is restored, the line voltage detection relay outputs 29a, 29b, 29c are restored, and the AND circuit 37 is established, and the trailing end interconnection confirmation timer 39 counts up. If it is determined that there is no line accident, and the reclosing condition 31 is satisfied, the AND circuit 33 is satisfied, and the circuit breaker 3
A closing instruction 34 is given to a. As a result, following the reclosing of the leading end circuit breaker 2a, the trailing end circuit breaker 3a is reclosed and the normal system state is restored.

This is to confirm that there is no accident in the line in consideration of the influence on the axial torque of the generator at the time of accident re-interruption of the transmission line close to the generator in the radial power system.
This is for turning on the circuit breaker on the generator side. If the accident continues or a re-accident occurs, the circuit breaker on the generator side will not be closed because the circuit breaker at the leading end will re-cut.

[0008]

In recent years, in an ultrahigh voltage system, the problem of excessive stability due to route disconnection in the case where high-speed reclosing is not performed is solved, and the restriction of the shaft torque dangerous section of the generator is reviewed to improve high Since it became possible to adopt the speed multi-phase re-closing method, the high speed single-phase three-phase re-closing method was revised to the high-speed multi-phase re-closing method in order to improve the re-closing execution rate. There is.

The problem here arises in the radial system in which the line fault is detected by the line PD year PT) and the line voltage is introduced to restore the line voltage detection relay.

Conventionally, 275kV for high-speed single-phase / three-phase reclosing
In the system, the line PD (PT) is installed in a single phase (representative phase), and it is not possible to confirm the presence or absence of the line voltage of each phase necessary for the polyphase reclosing. Therefore, the line PD (PT) is required for each phase, which is difficult to put into practical use in terms of hardware and cost.

The present invention has been made to solve the above problems, and in a radial system, the line PD (P
Regardless of the presence or absence of T), by confirming that the circuit breaker at the leading end is closed for a certain period of time, it is possible to confirm that there is no line fault and perform high-speed multi-phase reclosing for closing the circuit breaker at the trailing end. The purpose is to provide a reclosing method.

[0012]

The reclosing method of the protective relay device of the present invention is applied to a radial power supply system in which a generator is connected to a terminal, detects an accident in a transmission line, and once breaks the circuit breaker in the accident phase. A circuit for reclosing the circuit breaker after a predetermined period of time after the circuit is opened, which includes a first reclosing circuit starting unit, a second reclosing circuit starting unit, a no-voltage time timer unit, a trailing end link confirmation timer unit, and a leading end. A selection unit, a trailing end selection unit, a circuit breaker condition detection unit, and an output unit are provided.

The first reclosing circuit starting unit establishes the reclosing circuit starting condition by the operation of the protective relay device which detects an accident in the power transmitting unit. The no-voltage time timer unit extends the starting condition of the re-closing start unit by a predetermined re-closing non-voltage time for eliminating the accident. The leading end selection unit establishes the leading end selection setting when the protective relay device is installed at the leading end facing the generator-side terminal.

Then, the trailing end selecting section establishes the trailing end selection setting when the protective relay device is installed at the generator side terminal. The circuit breaker condition detector inputs the on / off state of the circuit breaker at the leading end facing the terminal on the generator side, and outputs when the three phases are on. The second reclosing circuit activation unit establishes the reclosing circuit activation condition when the output conditions of the trailing end selection unit and the circuit breaker condition detection unit are both satisfied. The trailing end link confirmation timer section counts a predetermined time for confirming the trailing end link confirmation of the start condition of the reclosing circuit starting unit.

Then, the output section confirms the reclosing condition when both the output conditions of the no-voltage time timer section and the leading end selection section are satisfied, or when the output of the trailing end connection confirmation timer section is satisfied, and the circuit breaker is confirmed. Output a closing command and close the circuit again.

[0016]

According to the present invention, the detection of no line fault is performed to confirm the "on" state of the circuit breaker at the leading end for a certain period of time, thereby reclosing the circuit. As a result, the line PD like the 275kV system
Even if (PT) can be installed in only a single phase, line faults in each phase can be detected, high-speed multiphase reclosing can be performed, and system stability can be maintained.

[0017]

Embodiments of the present invention will be described with reference to FIGS. 1 and 2 are block diagrams of a system configuration of a transmission line and a high-speed multiphase reclosing device according to an embodiment of the present invention. In FIGS. 1 and 2, the same parts and the like as those in FIGS. 3 and 4 are denoted by the same reference numerals.

When an accident occurs at point F in FIG. 1, a fault current flows through the power transmission line 1 and the transmission line protection relay devices 10 and 11 that take in the fault current through the current transformers 8 and 9 operate. This breaks the circuit breakers 2a and 3a to eliminate the accident.

At this time, if the pressure condition of the circuit breaker is normal, the reclosing preparation completion 23 is established, and the AND circuit 24 with the transmission line protection relay operation (R phase) 22a is established and the multiphase re-establishment is completed. Perform the circuit start 26. With the multiphase reclosing start 26, the reclosing non-voltage time timer 30 starts counting.

At the leading end, if the reclosing condition 31 is satisfied because the reclosing power condition is set to "leading end / simultaneous" 27, the AND circuit 33 is established after the reclosing no-voltage time timer 30 is counted. Then, a closing command 34 is given to the circuit breaker 2a. As a result, the leading edge circuit breaker 2a is turned on again.

When the leading end circuit breaker 2a is turned on when the trailing end reclosing power condition is selected and set to "subsequent end" 28,
AND circuit of 3 phase circuit breaker "ON" 2a, 2b, 2c 37
Is established and the count of the trailing end interconnection confirmation timer 39 is started. When the reclosing condition 31 is also satisfied, the AND circuit 33 is satisfied and the closing instruction 34 is given to the circuit breaker 3a. As a result, the trailing end circuit breaker 3a is turned on to return to the normal system state. The time limit of the trailing end interconnection confirmation timer 39 is longer than the time for confirming that there is no accident on the line.

Next, a case in which the trailing end interconnection confirmation timer 39 does not count up in the case of re-cutoff will be described. When a permanent accident (continuous accident) occurs at point F in FIG. 1, a fault current flows in the power transmission line 1 and the fault currents are taken through the current transformers 8 and 9 to protect the transmission line 10 and 11. Operates, thereby breaking the circuit breakers 2a and 3a to eliminate the accident.

At the leading end, if the pressure conditions of the circuit breaker are normal, the reclosing preparation completion 23 is established, and the AND circuit 24 with the transmission line protection relay operation (R phase) 22a is established. Perform a multi-phase reclosed startup 26. With the multiphase reclosing start 26, the reclosing no-voltage confirmation timer 30 is counted. When the reclosing condition 31 is satisfied, the AND circuit 33 is satisfied, and the circuit breaker 2
A closing command 34 is given to a and the breaker 2a is closed. At this time, the accident at the point F of the power transmission line continues because of a permanent accident, and the fault current flows through the power transmission line 1 again, and the fault current is taken in through the current transformer 8. 10 operates, and it is determined that the circuit is in the state of incomplete preparation for reclosing, and the circuit breaker 2a,
2b and 2c are cut off again. Therefore, if the time limit of the trailing end interconnection confirmation timer 39 at the trailing end is set to be longer than the re-cutting time of the leading end circuit breaker 2a, re-cutting will occur,
The trailing end is an AND circuit with the leading end breaker 2a "ON" 30a
37 is established at one time, but due to interruption of preparation at the leading edge
Since the circuit breakers 2a, 2b, 2c are turned off, the trailing end interconnection confirmation timer 39 cannot count up, and the trailing end circuit breaker 3a
Is not thrown. When the interconnection condition 31 is not satisfied, the circuit breakers 3b and 3c are shut off for the remaining phase after the reclosing period is given, and the final shutoff is performed. Therefore, it is possible to prevent an adverse effect such as application of a fault voltage to the generator connected to the trailing end due to re-injection during a fault.

Since the circuit breaker closing condition at the leading end is a reclosed condition (confirmation of two-phase interconnection), the circuit breaker conditions are transmitted to each other. Therefore, these conditions can be used. No special conditions need to be set.

From the above results, the line PD (P
Even in the radial power supply system without T), it is possible to implement the high-speed polyphase reclosing circuit necessary for maintaining the stability. In the above description, two terminals are described, but even in the case of three or more terminals, the partner end CB “ON” confirmation circuit may be configured as partner 1, partner 2 ,.

[0026]

As described above, according to the high-speed multiphase reclosing circuit of the present invention, it is necessary to maintain the stability by confirming the detection of no line fault by the leading end interruption even in the radial power supply system. It is possible to provide a high-speed polyphase reclosing circuit.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a power transmission line showing an embodiment of the present invention.

FIG. 2 is a block diagram of a high-speed polyphase reclosing circuit according to an embodiment of the present invention.

FIG. 3 is a system configuration diagram of a conventional power transmission line.

FIG. 4 is a block diagram of a conventional high speed polyphase reclosing circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transmission line, 2a, 2b, 2c, 3a, 3b, 3c ... Circuit breaker, 4, 5 ... Bus line, 6 ... Rear power supply, 7 ... Generator, 8,
9 ... Current transformer, 10, 11 ... Transmission line protection relay device, 12 ... Line fault detection relay, 24, 32, 33, 37, 38 ... AND circuit,
30 ... Reclosed no-voltage time timer, 35,36 ... OR circuit, 27,
28… Reclosed power supply condition selection tap, 39… Subsequent end interconnection confirmation timer.

Claims (3)

[Claims] 1. A protective relay which is applied to a radial power supply system to which a generator is connected at its end, and which opens a circuit breaker in the accident phase once after detecting an accident in a transmission line and recloses the circuit breaker after a predetermined time. It is a reclosing method for electrical equipment, and the reclosing starting part that establishes the reclosing starting condition by the operation of the protective relay that detects the accident of the transmission line, and the starting condition of this reclosing starting part A predetermined re-closed no-voltage time period for extending the no-voltage time timer section, and a leading end selection that establishes the leading end selection setting when the protective relay is installed at the leading end facing the terminal on the generator side. Department,
A protective relay device, comprising: an output unit that confirms the reclosing condition when both output conditions of the timer unit and the leading end selecting unit are satisfied and outputs a closing command to the circuit breaker to reclose the circuit. Re-closing method. 2. A protective relay which is applied to a radial power supply system to which a generator is connected at the end, and which recloses the circuit breaker a predetermined time after detecting an accident in a transmission line and once opening the circuit breaker in the accident phase. A reclosing method of an electric device, wherein when the protective relay device is installed at the terminal on the generator side, a trailing end selecting unit that establishes a selective setting of the trailing end is opposed to the terminal on the generator side. The circuit breaker condition detector that inputs the on / off state of the breaker at the leading end and outputs when all three phases are on, and the output condition of the trailing end selector and the circuit breaker condition detector are both satisfied again. The reclosing closing unit that satisfies the closing starting condition, the trailing end linking confirmation timer unit that measures the starting condition of the reclosing closing unit for a predetermined time for checking the trailing end linking, and the trailing end linking confirmation timer unit. Before confirming the reclosing condition when the output is established Reclosing schemes protective relay apparatus characterized by comprising an output unit for outputting reclosing the closing command to the circuit breaker. 3. The protection relay device according to claim 2, wherein the predetermined time of the trailing end link confirmation timer unit is set to be equal to or longer than the time for detecting and re-cutting an accident after reclosing the leading end circuit breaker. Closing method.