JP2008220051A - Power-transmission-line protection relay device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain high-speed operation and reliability of protection by achieving the same operation time as a main protection PCM relay device while making 20% of a protection range near a counterpart end become a high-speed shutoff state by a back-up protection DZ relay device even when a main protection relay device is interrupted or halted. <P>SOLUTION: A power-transmission-line protection relay device is provided with a protection system utilizing a communication line and a directional-distance protection system. The power-transmission-line protection relay device has a circuit for transferring directional-distance first-stage operating conditions to an other-line protection relay device, a circuit for receiving counterpart-terminal directional-distance first-stage operating conditions from the other-line protection relay device, and a circuit that switches a directional-distance second-stage shutoff output time or outputs a shutoff command on the condition that the counterpart-terminal directional-distance first-stage operating conditions are inputted. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power transmission line protection relay device for a power system.

  As is well known, the protection relay device has a mission of having no malfunction or malfunction in order to fulfill a heavy social responsibility of stable power supply. However, in the power system, the number of heavy load transmission lines is increasing more and more like the conventional multi-terminal system of 3-4 terminals from the conventional 2-line 2-terminal. In such a power system, the protection relay device is required to detect an accident with higher sensitivity, calculate an accident point with higher sensitivity, or determine an accident phase in order to stabilize the system. In order to satisfy these requirements, a digital current differential protection relay device (hereinafter referred to as a PCM relay device) is often applied. As shown in Non-Patent Document 1 and Non-Patent Document 2, PCM relay devices are used as main protection, usually in two systems in important systems, and are protected by devices in the operation system even when the system is defective or out of service. Therefore, it is mainly applied to important systems such as ultra-high voltage systems that require high reliability.

On the other hand, by using a protection theory different from that of the main protection method, back-up protection is used to improve reliability as protection. As a back-up protection method, a directional distance relay device (hereinafter referred to as a DZ relay device) that measures the direction of the accident point and the distance to the accident point using current and voltage at its own end is often employed.
FIG. 8 is a diagram in which a conventional protection relay device is applied to a parallel two-line power transmission line, and the prior art will be described using this. In FIG. 8, the power system is simplified and expressed by a two-terminal configuration of a local end and a counterpart end. Each terminal is connected to 1L, 2L of two transmission lines from the buses 1A, 1B, the circuit breakers 4A, 4B are connected to the power transmission line 1L, and the circuit breakers 41A, 41B are connected to the power transmission line 2L. Further, the power line 1L is input to the A-series PCM relay device 5AA from the instrument current transformer (CT) 3A, and the instrument current transformer (CT) 2A is connected to the B-series PCM relay device 5AB and the DZ relay device 6A for protection. And is operated with two main protection lines and one after-protection line. Similarly, the power transmission line 2L is input from the instrument current transformer (CT) 31A to the A series PCM relay apparatus 51AA, and the instrument current transformer (CT) 21A is connected to the B series PCM relay apparatus 51AB and the DZ relay apparatus 61A for protection. And is operated with two main protection lines and one after-protection line. The counterpart B terminal is also connected in the same manner as its own end, and data or signals are transmitted and received between the own end and the counterpart B terminal by the transmission means 7A, 7B or 71A, 71B.

  In FIG. 8, even if the communication line 7A of the A-series PCM relay devices 5AA and 5BA protecting the power transmission line 1L is faulty and the A-series PCM relay apparatuses 5AA and 5BB cannot be used, the B-series PCM relay Protection can be continued with 5AB and 5BB. In this way, the main protection has two systems, and the current differential protection relay system is used for both systems, and protection can be continued with the operation system apparatus even if the single system apparatus becomes defective or inactive.

However, if an operation time equivalent to that of the main protection PCM relay device can also be realized in the event of an accident in the protection zone, the main protection need not be divided into two systems, and the A series can be replaced with the PCM relay apparatus and the B series. Can be realized as a DZ relay device, and there is a merit that only one line is required for the communication line between the own end and the other end, but the DZ relay device uses the current and voltage at its own end to determine the direction of the accident point. It is a method to measure the distance to the accident point, and it is not possible to determine the distinction between the in-section accident and the other end bus accident. For this reason, the first stage of direction distance (DZ1 stage) that can be shut off at high speed covers about 80% of the total length of the transmission line to be protected (protection section) from the relay installation point, and about 20% of the near end of the other end. In the case of an accident within the range of the second distance of the direction distance (DZ2), the protection range. The DZ2 stage sets the protection range from about 120% to 150% of the protection zone so as to reliably detect the near-end accident. Since the partner bus accident and the next section also enter the protection range, the DZ2 stage must be timed. For this reason, conventionally, the main protection is divided into two lines so that the main protection function is not lost even if one of them is defective in transmission or at rest. In addition, in the DZ relay device, Patent Document 1 and Patent Document 2 propose a method using a communication line as a method of shortening the operation time even in the case of the other end near-end accident.
Development of protection relay system and improvement of maintenance operation efficiency Electric cooperative research Vol.59 No.1 p-36 Protection Relay System Basic Technology System Technical Report of the Institute of Electrical Engineers of Japan 641 p-76 Japanese Patent Laid-Open No. 9-93787 JP-A-6-276663

  As described above, in order to improve the reliability in the application to the power system, in preparation for unexpected situations such as failure of the protection relay device or device lock, the main protection includes two PCM relay devices, In many cases, a DZ relay device is employed. For this reason, there has been a problem that the economic burden is large, such as the need for capital investment including communication equipment for making the main protection device into two series. In addition, in the critical system, even if the main protection device is divided into two systems, if a failure occurs in one system, the system operation may be restricted, for example, by turning the load current back to another line in case of an emergency. This caused an increase in the burden on the city and the occurrence of economic losses due to a review of the load distribution on the supply route. For this reason, an alternative to the main protection relay device is demanded by increasing the operation time of the rear protection DZ relay device in the same level as the main protection. However, the method of Patent Document 1 is necessary to speed up the operation time of the rear protection DZ relay device. Since the communication line is shared with the main protection communication line, it is useless if the main protection communication line is defective. The method of Patent Document 2 also requires a dedicated communication line, which is economically disadvantageous.

  Therefore, even when the main protection relay device is faulty or inactive, the back-up protection DZ relay device enables high-speed shut-off even in the 20% range of the near end of the other party, and the same operation as the main protection PCM relay device. It is an object of the present invention to provide a method that can be realized easily without the need for additional installation of a new communication line in order to realize time and maintain high-speed operation and reliability.

  In order to solve the above-mentioned problem, in the present invention, in a power transmission line protection relay device having a protection method using a communication line and a direction distance protection method, a circuit for passing the direction distance first stage operation condition to another line protection relay device A circuit that receives the first-stage operation condition of the other terminal direction distance from the other line protection relay device, and outputs a cutoff command on condition that the first-stage operation condition of the other terminal direction distance is input, or the direction distance A circuit for switching the second stage cutoff output time is provided.

  According to the present invention, in an accident near the counterpart terminal, the first stage of the DZ relay of the counterpart terminal operates, and the own terminal DZ relay becomes the second stage operation area, but other lines (generally there are many parallel two lines) The first stage operating condition of the counterpart DZ is input via the main protection relay of the adjacent line), and it becomes possible to perform high speed cutoff by switching between high speed cutoff or second stage operation time limit. For this reason, it is equipped with a backup protection relay that enables high-speed interruption of accidents in the protection zone equivalent to the main protection function without adding a new transmission line or making two main protection relays. A power line protection relay device having the same reliability can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

  As a typical example, the case where a PCM relay is used as the main protection relay is shown. Needless to say, the transmission path is not limited to the PCM relay.

1 to 2 are configuration diagrams of a PCM relay device and a DZ relay device applied to a parallel two-line transmission line system according to Embodiment 1 of the present invention.

FIG. 1 is a diagram in which the conventional main protection PCM relay device of FIG. 8 is a series, and as a protection device for a transmission line 1L, an A series is a PCM relay apparatus 5A, 5B, a B series is a DZ relay apparatus 6A, 6B, As a protection device for the power transmission line 2L, a configuration is shown in which A series PCM relay devices 51A and 51B and B series DZ relay devices 61A and 61B are installed. Now, in the state where a failure has occurred in the communication line 7 of the A-series PCM relay devices 5A and 5B of the transmission line 1L, when an internal accident F occurs at the closest end within 20% of the transmission line 1LB terminal, The response of the A terminal B series DZ relay device 6A will be described. Since a failure has occurred in the communication line 7 in FIG. 1, the PCM relay device 5A at the A terminal detects the transmission failure CFA and outputs the transmission failure information CFA to the B-series DZ relay device 6A. On the other hand, in the B series DZ relay 6B of the B terminal, the distance first stage element B-Z1 operates in the near end internal accident F (B end DZ 1 stage operation). This distance first-stage element B-Z1 condition is output to the A-line PCM relay device 51B of the adjacent line, and transmitted from the PCM relay device 51B to the A-terminal A-line PCM relay device 51A via the communication line 71. The B-Z1 condition is output from the A terminal A series PCM relay device 51A to the B series DZ relay device 6A for protecting the transmission line 1L. FIG. 2 specifically shows each device response, and a portion other than the broken line shows a circuit diagram of the A terminal DZ relay device 6A of FIG. In FIG. 2, the distance second stage element DZ2 stage operating condition of the B-series DZ relay device 6A of the A terminal power transmission line 1L passes through the OR circuit 6AOR and excites the auxiliary relay 52TX by a timer 6AT in a preset time period. On the other hand, the distance first stage operating condition B-Z1 of the B-series DZ relay device 6B of the B-end transmission line 1L passes through the communication line 71 of the adjacent line, and the NAND circuit of the A-series PCM relay device 51A of the A-terminal transmission line 2L It is input to 51ANAND. The condition that the change-over switch 43C of the A-end power transmission line 2LPCM relay device is used and no transmission failure occurs is input to the NAND circuit 51ANAND, and the first distance of the B-series DZ relay device 6B of the B-end power transmission line 1L is first. An AND condition with the stage operation condition B-Z1 condition is input to the AND circuit 6AAND. The transmission failure condition CFA of the A-series PCM relay device 5A of the A-end transmission line 1L is input to the AND circuit 6AAND. The output of the AND circuit 6AAND is input to the OR circuit 6AOR, and the auxiliary relay 52TX is excited.

  The PCM relay devices 5A and 5B of the power transmission line 1L are in a state where normal determination cannot be made due to the communication line 7 failure. In this state, when an internal accident F occurs near the end of the B terminal of the transmission line 1L, the distance B first stage B-Z1 of the B terminal B series operates, and the A series PCM relay devices 51B and 51A of the adjacent line operate. Is input to the A-end B-series DZ relay device 6A via the A-line 51A of the A-end power transmission line 2L.

The D-Z relay device 6A of the A-end transmission line 1LB series is not a transmission failure than the A-series PCM relay device 51A of the transmission line 2L, on the condition that the A series PCM relay device 5A detects a transmission failure. If it is established that the changeover switch 43C is used, the first-stage operation condition B-Z1 of the B terminal 1LDZ relay device 6B does not wait for the timer 6AT of the DZ2-stage operation condition to wait for the OR circuit. Bypassing with 6AOR, 52TX is excited to enable instantaneous interruption (6A trip command). As a result, even in the F point accident at the close terminal 1L of the B terminal, the breaker of the A terminal 1L can be shut off at high speed in the DZ relay 6A of the A terminal 1L.

  FIG. 3 shows a second embodiment of the present invention. The description of the same circuit as that of the first embodiment is omitted. FIG. 3 is a diagram in which an AND circuit 6AAND2 is added as an input condition of the OR circuit 6AOR in FIG. 2 which is the first embodiment. 6AT1 is a timer for shortening the time limit (timer) of the second direction distance (DZ2 step) operation. 6AT1 may be set to 0 or omitted. Here, 6AT1 is provided between the DZ2 stage operation and 6AAND2, but it may be provided between 6AAND2 and 6AOR.

  By setting 6AT1 <6AT, when an accident F in the vicinity of the B terminal 1L occurs, the A terminal 1LDZ relay device 6A becomes DZ2 stage according to the distance first stage operation condition B-Z1 of the B terminal 1LDZ relay apparatus 6B. It is possible to excite 52TX after 6AT1 in which the time limit of operation is shortened and to output a cutoff output. In addition, because it is conditional on DZ2 stage operation of its own terminal DZ relay, it can be shut off when an accident is detected reliably, so even if it receives a false signal of B-Z1 operation, it prevents malfunction. , Can increase the reliability.

FIG. 4 is a diagram showing a third embodiment, in which an OR circuit 6AOR2 is added as an input condition of the AND circuit 6AAND2 of FIG. 3, and a SU element (or a Mor element) of a direction distance element is used as an input condition. It is added. The auxiliary relay 52TX is energized and a cutoff command is given when either the distance element second stage (DZ2 stage) operating condition or the direction distance element (SU) operating condition is satisfied, so that the high-speed cutoff command condition is more reliably established. Can be output.

  FIG. 5 is obtained by adding a changeover switch 43C lock condition to the OR circuit 5AOR in addition to the transmission failure condition CFA of the A terminal A series PCM relay device 5A. 6 is obtained by adding a changeover switch 43C lock condition to the OR circuit 5AOR to the transmission failure condition CFA of the A terminal A series PCM relay device 5A. FIG. 7 is obtained by adding a changeover switch 43C lock condition to the OR circuit 5AOR to the transmission failure condition CFA of the A terminal A series PCM relay device 5A in FIG.

The PCM relay devices 5A and 5B of the power transmission line 1L are in a state where normal determination cannot be made due to the communication line 7 failure. In this state, when an internal accident F occurs near the end of the B terminal of the transmission line 1L, the distance B first stage B-Z1 of the B terminal B series operates, and the A series PCM relay devices 51B and 51A of the adjacent line operate. Is input to the A-end B-series DZ relay device 6A via the A-line 51A of the A-end power transmission line 2L. In FIG. 5, the D-Z relay device 6A of the A-end power transmission line 1LB series has an A-series PCM of the transmission line 2L on the condition that the A-series PCM relay apparatus 5A has detected a transmission failure CFA or the changeover switch 43C is locked. If it is established from the relay device 51A that there is no transmission failure and the change-over switch 43C is used, the first-stage operation condition B-Z1 operation of the B terminal 1LDZ relay device 6B satisfies the DZ2-stage operation condition. Even without waiting for the time limit of the timer 6AT, it is bypassed by the OR circuit 6AOR, and 52TX is excited to enable instantaneous interruption.

  According to the present embodiment, when the protection device for the parallel two-line power transmission line is configured with two systems of the main protection PCM relay and the rear protection DZ relay, the main protection PCM relay becomes unusable due to a failure or a pause. Even when the device operation state changeover switch is locked, the operating condition of the main protection PCM relay device is equivalent by transmitting the first-stage distance element operation condition to the back-end protection DZ relay device via the adjacent communication line. High-speed shut-off. Similarly, in FIGS. 6 and 7, even when the main protection PCM relay becomes unusable due to a failure or suspension, or when the device operation state changeover switch is locked, the distance first-stage element operation condition or the direction element operation condition is By transmitting to the back-end protection DZ relay device via the communication line of the adjacent line, high-speed disconnection by 6AT1 hour can be realized.

  In the above, the transmission failure CFA condition of the own line 1L main protection relay and the transmission failure does not occur in the adjacent line 2L, and the 43C “use” condition is added to the condition by AND. It goes without saying that can be omitted. Further, in the description, the power transmission line 1L is mainly described, but even when the power transmission line 2L is mainly used, the same response as described above is obtained.

The figure which shows the system configuration | structure of the Example of this invention. The block diagram which shows the 1st Example of this invention Block diagram showing a second embodiment of the present invention Block diagram showing a third embodiment of the present invention The block diagram which shows the 4th Example of this invention The block diagram which shows the 4th Example of this invention The block diagram which shows the 4th Example of this invention The system block diagram which shows the form of a prior art.

Explanation of symbols

1A A terminal bus 1B B terminal bus 2A A terminal 1L Retrofitting protection current transformer (CT)
3A A terminal 1L main protection instrument current transformer (CT)
2B B terminal 1L Current protection instrument current transformer (CT)
3B B terminal 1L Main protection instrument current transformer (CT)
21A, 31A, 21B, 31B 2L Instrument Current Transformer (CT)
4A, 4B, 41A, 41B Circuit breaker 1L, 2L Transmission line 5A, 5B, 51A, 51B Main protection (PCM) relay device 6A, 6B, 61A, 61B Back-end protection (DZ) relay device CFA Transmission failure condition 6AT, 6AT1 Timer 6AAND AND circuit 5AOR, 6AOR OR circuit 51A NAND NAND circuit 52TX Auxiliary relays 7, 71 Transmission path (communication line)

Claims (10)

  In a power transmission line protection relay device equipped with a protection method that uses a communication line and a directional distance protection method, a circuit that passes the first stage operating condition of the directional distance to the other line protection relay device, and the other terminal direction from the other line protection relay device A power line protection relay device comprising: a circuit that receives a first-stage distance operating condition; and a circuit that outputs a shut-off command on condition that the first-stage operating condition for the distance to the counterpart terminal is input. .   In a power transmission line protection relay device equipped with a protection method that uses a communication line and a directional distance protection method, a circuit that passes the first operating condition of the direction distance to the other line protection relay device, and the other terminal direction from the other line protection relay device A circuit that receives a first-stage operation condition for a distance, and a circuit that switches a second-stage cutoff output time for a direction distance on condition that the first-stage operation condition for the distance direction of the mating terminal is input. Transmission line protection relay device.   In a power transmission line protection relay device having a protection method using a communication line and a direction distance protection method, a circuit for passing a direction distance element operation condition to another line protection relay device, and a partner terminal direction distance element from the other line protection relay device A power line comprising: a circuit that receives an operating condition; and a circuit that switches a direction distance second stage or a direction distance element cutoff output time on condition that the partner terminal direction distance element operating condition is input. Protection relay device.   In a power line protection relay device using a protection method that uses a communication line for the main protection relay device and a directional distance protection method for the back-end protection relay device, the first-stage operating condition for the back-end protection direction distance is set to the other line main protection relay device. Circuit, a circuit that receives the first-stage operating condition of the other terminal direction distance from the other line main protection relay device, and a cut-off command on condition that the first-stage operating condition of the other terminal direction distance is input A power transmission line protection relay device comprising a circuit and a rear protection relay device.   In a power line protection relay device using a protection method that uses a communication line for the main protection relay device and a directional distance protection method for the back-end protection relay device, the first-stage operating condition for the back-end protection direction distance is set to the other line main protection relay device Circuit, a circuit that receives the first-stage operating condition of the other terminal direction distance from the other line main protection relay device, and the second direction distance on the condition that the first-stage operating condition of the other terminal direction distance is input. A transmission line protection relay device comprising: a circuit for switching a cutoff output time; and a backup protection relay device.   A circuit that passes a direction distance element operating condition to another line main protection relay device in a power line protection relay device that uses a protection method that uses a communication line for the main protection relay device and a directional distance protection method for a backup protection relay device. And the circuit receiving the other terminal direction distance element operation condition from the other line main protection relay device, and the second direction distance element or direction distance element cutoff output time on condition that the other terminal direction distance element operation condition is input. A transmission line protection relay device comprising: a circuit for switching; and a backup protection relay device.   5. The power transmission line protection relay device according to claim 1, wherein the detection of the own line transmission failure is added (AND) to the condition of the cutoff command output.   The transmission line protection relay device according to any one of claims 2, 3, 5, and 6, wherein the fact that a transmission failure of the own line is detected is added to a switching condition (AND).   5. The transmission failure of the own line is detected, or the condition of the own line 43C lock (main protection lock or carrier lock) is added to the condition of the shutoff command output (AND). Power transmission line protection relay device.   5. A failure of own line transmission is detected, or the own line 43C lock (main protection lock or carrier lock) condition is added to the switching condition (AND). The power transmission line protection relay device according to claim 6.

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