JP4607804B2 - Protective relay device - Google Patents

Description

  The present invention relates to a protective relay device in which when a system fault occurs when a main protection device is locked, a fault protection section is separated from a power system by a backup protection device.

  In some cases, only one line of protective relay devices for protecting the transmission line equipment of the power system is installed with priority given to economy. The protection system in such a case is based on a main protection device that protects the power transmission facility so that a minimum power outage range is sufficient when an accident occurs, and the main protection device is suspended or is operated by the main protection relay device. It consists of a back-end protection device that protects a plurality of facilities including a power transmission facility as a protection target of the main protection device when protection fails (see, for example, Non-Patent Document 1).

A multi-stage time difference distance relay system is applied to the protection of the transmission line to protect the transmission line, and a three-stage time difference distance relay system is generally used. When applying the three-step time-distance distance relay system for transmission line protection, the first step of the distance relay is set to respond only to accidents in up to 80% of the transmission line of the protection section, and the second stage is the opposite bus. In order to detect this accident reliably, it is set to about 120% of its own section, and the adjacent section protection relay is coordinated with distance setting and time setting. And the 3rd stage is set to about 300% of a protection section transmission line, and remote protection is carried out at the time of serious accidents, such as circuit breaker non-operation in the next section accident (for example, refer nonpatent literature 2).
Edited by Izumi Mitani, “Digital Relay Practical Reader”, Ohmsha (pages 17-18) Yoshihide Hase Co-authored by Michio Masui “Protective Relay Technology” Tokyo Denki University Press (pp. 249-251)

  In the case of a protection system in which only one system of protective relay device is installed for the protection target, when the main protection function is lost due to a failure of the main protection device or during periodic inspection (hereinafter referred to as when the main protection device is locked) If the operation of the power transmission line equipment as the protection target is stopped or cannot be stopped, it must be operated so that it can be prepared in the event of an accident by a back-up protection device. When the operation of the power transmission line facility is stopped, it is necessary to perform a system operation that allows power failure or configures a detour and supplies power to the load.

  Conventionally, when the main protection device is locked so that it is protected by the back-end protection device, if an accident occurs in the transmission line equipment, the distance relay first stage of the back-end protection device can be shortened early. A method is used to separate the accident section from the grid. However, in this method, the first step of the distance relay responds only to the accident in the section up to 80% of the protection section transmission line as described above, and therefore cannot operate at the time of the accident near the opposite terminal more than 80%.

  As a countermeasure, a method of separating the fault section from the system in a shorter time than by shortening the time limit of the second stage of the distance relay can be considered, but this method also works for a bus accident at the opposite terminal. It can happen.

  The present invention has been made in order to solve the above-described problem. When there is only one protective relay device, the transmission line facility is not stopped without stopping the transmission line facility when the main protection device is locked. It is an object of the present invention to provide a protective relay device that can isolate only a transmission line facility in which an accident has occurred in a short time without expanding the range of power failure by a back-up protection device.

In order to achieve the above-mentioned object , the invention according to claim 1 is the multi-step time difference distance when the main protection function of the main protection relay device installed at both terminals of the transmission line as the protection target is locked. In the protective relay device in which the transmission line is protected by a backup protection relay device, the backup protection relay device includes a directional relay that detects an accident that occurs in the opposite terminal direction of the transmission line. , The distance relay second stage that detects an accident in the opposite terminal direction, and the operation of both the direction relay and the distance relay second stage after the predetermined time elapses, and outputs a disconnection command to the circuit breaker of its own terminal An operation time delay timer, a main protection relay operation condition input means for inputting an operation condition of the main protection relay of its own terminal, an output of the main protection relay operation condition input means, the operation of the direction relay and the second step of the distance relay Wherein the operation time delay timer to reduce the delay time of the bypass or the timer, characterized by comprising a means for outputting a second stage cutoff command to the circuit breaker of the self terminal by.

  According to the present invention, when the main protection device is locked, the transmission line equipment is not stopped, and even if an accident occurs in the transmission line equipment, the directional element operation condition of the auxiliary protection relay device at the opposite terminal or the own terminal According to the main protection relay operating conditions, the operation delay timer corresponding to the second stage of the rear protection relay device of its own terminal is bypassed or the operation time limit is shortened, so the accident section can be separated in a short time it can.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a protective relay device according to the present invention will be described with reference to the drawings.
In addition, about the components and function which are common throughout each figure, the same code | symbol shall be attached | subjected and the overlapping description shall be abbreviate | omitted suitably.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.
(Constitution)
First, the overall configuration of the present embodiment will be described with reference to the overall configuration diagram of FIG.
In FIG. 1, A and B are electric stations such as a power plant and a substation, respectively, and 11 and 12 are first two-line first line transmission lines (hereinafter referred to as 1L lines) that link the electric stations A and B. ) And the second line transmission line (hereinafter referred to as 2L line). In the electric station A, the circuit breakers 31a and 32a are connected to the bus 2a. Similarly, in the electric station B, the circuit breakers 31b and 32b are connected to the bus 2b.

  41a1, 41a2, 41b1, 41b2, 42a1, 42a2, 42b1 and 42b2 are current transformers, and 5a and 5b are voltage transformers. Of the current transformers, the detected electric quantity output from the current transformer with the sign suffix of 1 is input to the main protection relay devices 61a, 61b, 62a and 62b, respectively, and the current transformer with the sign suffix of 2 The amount of detected electricity output from is input to the backup protection relay devices 71a, 71b, 72a and 72b, respectively.

  Then, the detected amount of electricity output from the voltage transformer 5a is input to the main protection relay devices 61a and 62a and the rear protection protection relay devices 71a and 72a of the electric station A, respectively. Similarly, the detected electricity output from the voltage transformer 5b is input to the main protection relay devices 61b and 62b and the rear protection relay devices 71b and 72b at the electric station B, respectively.

  81a, 81b, 82a, and 82b are transmission devices that mutually communicate the transmission information of the protective relay device between the electric stations A and B using microwaves, power line carriers, optical signals, and the like. Among these transmission devices, 81a is an electric device. The transmission information of the main protection relay device 61a provided on the 1L line 11 side of the station A and the transmission information of the backup protection relay device 72a provided on the 2L side are transmitted through the transmission route 91 for the 1L line 11 to the B electric The transmission information is transmitted to the transmission device 81b installed at the site, and conversely, the transmission information transmitted from the transmission device 81b is passed to the main protection relay device 61a and the rear protection protection relay device 72a.

  The transmission device 82a transmits the transmission information of the main protection relay device 62a provided on the 2L line 12 side of the electric station A and the transmission information of the backup protection relay device 71a provided on the 1L line 11 side to the 2L line. 12 is transmitted to the transmission device 82b installed at the B electric station by the transmission route 92 for 12 and the transmission information transmitted from the transmission device 82b is conversely passed to the main protection relay device 62a and the rear protection protection relay device 71a. It is configured as follows.

  Similarly to the transmission devices 81a and 82a at the electric station A, the transmission devices 81b and 82b installed at the electric station B are also connected to the main protective relay devices 61b and 62b and the rear protection protective relay devices 71b and 72b.

  The transmission route of the backup protection relay device may be configured to use a transmission route of a line different from that of the main protection relay device, or may be transmitted through the transmission route of the same line as the main protection relay device. Alternatively, it may be realized by means for providing a dedicated transmission route.

  The above-described backup protection relay devices 71a, 71b, 72a and 72b are each equipped with a similar processing circuit and means to which a multi-step distance relay system is applied, and FIG. 2 is a block diagram depicting a backup protection relay device 71a installed on the 1L line 11 side.

  In FIG. 2, reference numeral 711 denotes a three-stage distance relay that inputs the system electric quantity detected by the current transformer 41a and the voltage transformer 5a to determine an accident. The accident determination method is the same as that processed by the conventional distance relay, 712 is the reactance relay that constitutes the distance relay second stage (X2), and 713 is the distance relay third stage that also serves as a direction element. This is the MO relay (MHO). FIG. 3 is a diagram showing the characteristics of these mor relays and reactance relays. X1 indicates the characteristic of the reactance relay constituting the first stage of the distance relay described later.

  The MO relay (MHO) 713 operates when an accident in the direction of the opposing terminal occurs in the protection target. Information on the result of the operation of the MO relay (MHO) 713 is transmitted to the backup protection relay device 71b of the opposite terminal B on the 1L line 11 side.

  Reference numeral 714 denotes an opposite terminal transmission information receiving means (in the figure, for receiving transmission information from the auxiliary protection relay device 71b on the 1L line 11 side of the opposite terminal B via the transmission apparatuses 82b and 82a of the transmission route 92 for the 2L line 12. Terminal B transmission information receiving means). When the 3-stage distance relay 711 of the 1L line 11 side protection relay device 71b provided at the terminal B operates, it outputs a signal of logical value “1”, and when it does not operate, outputs a signal of logical value “0”. Output. These signals are transmitted as transmission information to the backup protection relay device 71a provided at the terminal A through the transmission device 82b, the transmission route 92, and the transmission device 82a. As a result, the terminal B transmission information receiving means 714 provided in the auxiliary protection relay device 71a of the terminal A is a signal having a logical value “1” or “0” according to the transmission information transmitted from the terminal B. Is output.

  Reference numeral 716 denotes an AND circuit, which inputs the output signal of the distance relay second stage (X2) 712 and the output signal of the MO relay (MHO) 713 constituting the three-stage distance relay 711, and outputs the signals of these elements 712 and 713 When both are logical values “1”, a signal of logical value “1” is output. Reference numeral 718 denotes an operation time delay timer corresponding to the second stage. When the AND circuit 716 continuously outputs the signal “1” for the set time period td or more, the logic value “1” is counted after the set time period td has elapsed since the input time point. The signal is output. Note that the setting time limit td is determined so that protection coordination between the three-step distance relay 711 and, for example, a bus protection relay device (not shown) is taken, that is, before the bus protection relay device operates. In order to prevent the electric device 71a from operating, it is set to a time (usually about 0.3 to 0.5 seconds) longer than the operation time of the busbar protective relay device.

  In this way, when the output signal of the distance relay second stage (X2) 712 and the output signal of the MO relay (MHO) 713 are continuously output for the set time limit td set by the operation delay timer, the operation is performed. The output signal of logical value “1” output from the time delay timer 718 is input to the OR circuit 717 and output as a second-stage cutoff command to the circuit breaker 31a installed on the 1L line 11 side of the own terminal A. The

Reference numeral 715 denotes an AND circuit. When the output signal of the AND circuit 716 and the output signal of the terminal B operation condition receiving unit 714 both have the logical value “1” and the input condition is satisfied, the logical value “1”. Is output to the circuit breaker 31a of its own terminal A through the OR circuit 717 as a second-stage cutoff command.
The relay and logic sequence circuit shown in FIG. 2 can also be realized by a digital relay using a microcomputer.

(Function)
Next, the operation of the present embodiment will be described with reference to FIG.
4 shows that when the main protection relay devices 61a and 61b of the 1L line 11 in the overall configuration diagram shown in FIG. 1 are in the main protection lock state (represented by x in the figure), the 1L line 11 A state in which an accident occurred separately at the F1 point or the F2 point of the bus 2b of the terminal B is shown.

  The accident point F1 is an internal accident in the protection section of the main protection relay devices 61a and 61b, and the accident point F2 is outside the protection section of the main protection relay devices 61a and 61b, and further protection is provided at the terminal A. Assume that the accident is within the operating range of the distance relay second stage X2 of the relay device 71a.

  Hereinafter, how a supplementary protective relay device 71a provided on the 1L line 11 side responds when a system fault occurs in F1 and F2 will be described.

<If a system fault occurs at F1>
When a system fault F1 occurs in the power transmission line 1L, in FIG. 2, the rear-end protective relay device 71a of the terminal A operates the distance relay second stage (X2) 712 and the Mor relay (MHO) 713. As a result, the AND circuit 716 generates an output signal having a logical value “1” because the operating condition is satisfied. The operation delay timer 718 receives the AND circuit 716 output signal “1” and starts counting the operation time limit.

  On the other hand, at the time of this F1 accident, also in the auxiliary protection relay device 71b of the opposite terminal B, the output signals of the distance relay second stage (X2) 712 and the MO relay (MHO) 713 operate together and each have a logical value “1”. The signal is output. The backup protection relay device 71b of the terminal B transmits the operating condition of the MO relay (MHO) 713 as transmission information to the backup protection relay device 71a of the terminal A through the transmission device 82b, the transmission route 92, and the transmission device 82a. Then, the terminal B operating condition receiving means 714 provided in the auxiliary protection relay device 71a of the terminal A outputs a signal having a logical value “1” according to the transmission information transmitted from the terminal B.

  As a result, since the input condition of the AND circuit 715 is satisfied in the auxiliary protection relay device 71a of the terminal A, the signal “1” is output from the AND circuit 715 regardless of the count of the operation delay timer 718. The second stage cutoff command is output to the circuit breaker 31a of its own terminal A through the OR circuit 717.

  As described above, in the case of an internal accident in the protection section such as the accident point F1, the second stage cut-off command is output in a short time by bypassing the operation delay timer 718 corresponding to the second stage from the backup protection relay device 71a. Then, the circuit breaker 31a of its own terminal is shut off.

  The reverse protection relay device 71b of the counter terminal B responds in the same manner, and the circuit breaker 31b of the terminal B is cut off by the second-stage cutoff command. In this way, the accident F1 in the transmission line section that occurs when the main protection relay device is locked is separated from the power system in a short time by the response of the backup protection relay devices 71a and 71b.

<If a system fault occurs at F2>
Since the fault point F2 occurring in the bus 2b of the terminal B is within the set distance of the distance relay second stage (X2) 712 for the terminal protection relay device 71a, the second stage (X2) of the distance relay in FIG. ) 712 and the MO relay (MHO) 713 operate together to satisfy the operating condition of the AND circuit 716, and therefore, the AND circuit 716 outputs a logic signal “1”. Further, the operation condition “1” signal is transmitted to the terminal B as transmission information by the operation of the MO relay (MHO) 713.

  However, since the accident point F2 is an external accident when viewed from the backup protection relay device 71b installed at the terminal B, the MO relay (MHO) 713 at the terminal B does not operate. For this reason, the transmission information of the backup protection relay device 71b transmitted from the terminal B to the terminal A is a signal “0”, and the terminal B operating condition receiving means provided in the backup protection relay device 71a of the terminal A The signal output from 714 is “0”, and the AND circuit 715 outputs a logic signal “regardless of whether the operating conditions of the distance relay second stage (X2) 712 and the MO relay (MHO) 713 of the terminal A are satisfied. The 1 "signal is not output. As a result, the operation time delay timer 718 continues counting the operation time period started from the time when the logic signal “1” is input from the AND circuit 716 without being bypassed by the AND circuit 715.

  By the way, each electric station A and B is provided with a bus protection relay device as described above, and the operation time limit of this bus protection relay device is set shorter than the set time limit of the operation delay timer 718. Therefore, the bus protection relay device operates before the count time of the operation delay timer 718 reaches the set time, and the circuit breaker 31b of the terminal B is disconnected.

  As a result, since the fault point F2 is separated from the power system, the fault current does not flow through the 1L line 11 of the terminal A. Therefore, the distance relay second stage (X2) 712 and the MO relay (MHO) 713 of the terminal A are Both return, and the second-stage cutoff command for the circuit breaker 31a at the terminal A is not output.

  Therefore, in the case of an accident behind the counter terminal B such as the accident point F2, since the second-stage cutoff output is not output from the backup protection relay device 71a, it is possible to avoid extending the power failure range to the 1L line 11.

(effect)
As described above, according to the first embodiment, when there is only one protection device, the transmission line facility is not stopped when the main protection device is locked, and an accident occurs in the transmission line facility. Also, the accident section can be separated from the power system in a short time by bypassing or shortening the timer corresponding to the second stage of the back protection relay device according to the operating conditions of the direction element of the back protection relay device of the opposite terminal Can do. Also, in the event of an accident behind the opposite end that causes the second stage of the distance relay to operate, the power outage range can be expanded to a healthy power transmission line facility through time coordination by a timer equivalent to the conventional second stage. Can be prevented.

Second Embodiment (Corresponding to Claim 2)
The second embodiment will be described with reference to FIGS. 5 and 6.
(Constitution)
FIG. 5 is an overall configuration diagram of the present embodiment, and FIG. 6 is a block diagram of a backup protection relay device employed in the present embodiment.
The major difference between the present embodiment and the first embodiment is that the main protection relay devices 61a, 61b, 62a and 62b are replaced by the rear protection protection relay devices 71a ', 71b', 72a 'and 72b as shown in FIG. To the main protection relay operating conditions C1a, C1b, C2a and C2b, respectively, and the output signals of the backup protection relay devices 71a ′, 71b ′, 72a ′ and 72b ′ are not transmitted between the electric stations. Instead of providing the receiving means 714 for receiving the transmission information transmitted from the 1L line 11 side backup protection relay device 71b installed at the opposite terminal B of the terminal A as shown in FIG. In addition, the main protection relay operating condition C1a output from the main protection relay device 61a of the own terminal A is replaced. Since other configurations are not particularly changed, description thereof is omitted.

In FIG. 6, the configuration of the backup protection relay device 71a ′ of this embodiment will be described in a little more detail.
That is, in FIG. 6, the output signal of the distance relay second stage (X2) 712 constituting the three-stage distance relay 711 and the output signal of the Mor relay (MHO) 713 are input to the AND circuit 716, and this AND circuit 716 Is output to the operation delay timer 718, and the output signal of the operation delay timer 718 is input to the OR circuit 717.

  The output signal of the main protection relay operation condition input means 719 for inputting the main protection relay operation condition C1a output from the main protection relay device 61a and the output signal of the AND circuit 716 are used as input signals of the AND circuit 715. The output signal of the AND circuit 715 is input to the OR circuit 717.

  In the present embodiment, the main protection relay device 61a is not the first stage of the distance relay as in the first embodiment, but a relay device such as a current differential relay system or a line selection relay system is adopted. .

(Function)
In the present embodiment, when attention is paid to the operation of the auxiliary protection relay device 71a ′ installed on the 1L line 11 side of the terminal A, the main protection relay operating condition output from the main protection relay device 61a for the AND circuit 716. Since the operation delay timer 718 corresponding to the second stage is bypassed when both the input conditions of the C1a and the output signal of the three-stage distance relay 711 are satisfied, for example, the main protection relay 61a Even if the circuit breaker trip circuit or the circuit that takes in external conditions is defective, if the accident detection processing unit (so-called relay calculation unit) of the main protective relay is operating normally, the output of this accident determination processing unit Thus, by bypassing the operation time delay timer 718 corresponding to the second stage or shortening the timer time period, the accident section can be separated in a short time.

(effect)
As described above, according to the second embodiment, when there is only one protection device, the transmission line equipment is not stopped when the main protection device is locked, and an accident occurs in the transmission line equipment. However, since the operation delay timer 718 corresponding to the second stage of the backup protection relay device is bypassed according to the main protection relay operating condition of the own terminal, the accident section can be separated in a short time. The same effect as that of the embodiment can be obtained.
Further, since the information transmission between the opposing terminals is not required, the configuration of the entire system can be simplified as compared with the first embodiment.

(Modification)
The present invention is not limited to the first embodiment or the second embodiment described above. As described in the following (1) to (4), the first embodiment or the second embodiment. The object of the present invention can be achieved even if some functions are added or changed with respect to the protective relay device in the form.

  (1). When the accident point F1 is in 80 to 100% of the transmission line protection section, the backup protection relay device 71a shown in FIG. 2 is an operation delay timer 718 corresponding to the second stage by the distance relay second stage (X2) 712. However, in order to be able to respond to an internal accident within 80% of the protection section, the distance relay second stage (X2) 712 is replaced with the distance relay first stage (shown in FIG. 3). X1) may be used. In this case, the second-stage cutoff command can be output only with the operating conditions of the first stage (X1) of the distance relay at its own terminal. Accordingly, it is possible to omit the receiving means 714, the AND circuit 715, etc., for transmitting the operating condition to the counter terminal and receiving the operating condition of the transmission signal from the counter terminal.

  (2). 2 and FIG. 6, the mor relay MHO also serves as the distance relay third stage, but the distance relay third stage and the direction relay are mounted separately. It may be.

  (3). 2 and 6, when the input condition of the AND circuit 715 is satisfied, instead of adding the output to the OR circuit 717 and bypassing the operation delay timer 718, the operation protection relay device 71 a, 71 a ′ The same effect can be obtained even if the timer set value of the delay timer 718 is shortened.

  (4). In the after-protection relay devices 71a and 71a ′ shown in FIG. 2 and FIG. 6, as shown in FIGS. 7A and 7B, the operation delay timer is bypassed or the delay time of the timer is shortened. It is also possible to limit the operation condition by adding the main protection device lock condition (device failure, power supply interruption, etc.) of the main protection relay device 61a as the input condition of the AND circuit 715.

BRIEF DESCRIPTION OF THE DRAWINGS The whole block diagram which shows 1st Embodiment of the protection relay apparatus by this invention. 1 is a block diagram showing a first embodiment of the present invention. The example figure of the relay characteristic regarding this invention. The block diagram for demonstrating operation | movement of the 1st Embodiment of this invention. The whole block diagram which shows 2nd Embodiment of the protection relay apparatus by this invention. The block diagram which shows the 2nd Embodiment of this invention. (A), (b) is a block diagram which shows the modification of 1st Embodiment and 2nd Embodiment, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 12 ... Power transmission line, 2a, 2b ... Busbar, 31a, 31b, 32a, 32b ... Circuit breaker, 41a1, 41a2, 41b1, 41b2 ... Current transformer, 42a1, 42a2, 42b1, 42b2 ... Current transformer, 5a, 5b: Voltage transformer, 61a, 61b, 62a, 62b ... Main protection relay device, 71a, 71b, 72a, 72b (71a ', 71b', 72a ', 72b') ... Back protection protection relay device, 711 ... 3 Step distance relay, 712 ... Second stage (X2) of distance relay, 713 ... Mo relay (MHO), 714 ... Opposing terminal (terminal B) operating condition receiving means, 715 ... AND circuit, 716 ... AND circuit, 717 ... OR Circuit, 718 ... Delay timer during operation, 719 ... Main protection relay operation condition input means, 720 ... Main protection function lock condition, 81a, 81b, 82a, 82b ... Transmission device 91, 92 ... transmission route.

Claims (1)

When the main protection function of the main protection relay installed at both terminals of the transmission line as the protection target is locked, the transmission line is protected by the back-up protection relay of the multi-stage time difference distance relay method. In the protective relay device
The rear protection relay device is
A direction relay that detects an accident that occurred in the direction of the opposite terminal of the transmission line;
A distance relay second stage for detecting an accident in the opposite terminal direction;
An operation delay timer for generating an output after a predetermined time has elapsed since both of the direction relay and the distance relay second stage have been operated,
Main protection relay operating condition input means for inputting the operating condition of the main protective relay of the own terminal;
By bypassing the operation time delay timer or shortening the delay time of the timer by the output of the main protection relay operating condition input means, the operation of the direction relay and the distance relay second stage, the second stage of the self-terminal breaker Means for outputting a shutoff command;
A protective relay device comprising:

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