JP2015154669A - ground fault protection relay system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly and securely remove a fault even when a main protection function of a main protection relay device is lost.SOLUTION: A ground fault direction relay device 2comprises: an information transmission unit 23 for making a main protection relay device 1at the own side terminal transmit PCM information including ground fault detection information showing that a ground fault has been detected, to a main protection relay device 1at the opposite side terminal; an information acquisition unit 24 for acquiring ground fault detection information on a ground fault direction relay device 2at the opposite side terminal from PCM information transmitted from the main protection relay device 1at the opposite side terminal to the main protection relay device 1at the own side terminal; and a calculation output unit 25 for reducing a predetermined period to output an interruption command to a circuit breaker CBat the own side terminal, when a ground fault is detected at the own side terminal and the information acquisition unit 24 acquires ground fault detection information or when a ground fault is detected at the own side terminal, the information acquisition unit 24 does not acquire ground fault detection information, and a ground fault is not detected on a power transmission line L2 adjacent to the own side terminal.

Description

  The present invention relates to a ground fault direction relay device which is a backup protection relay device when the main protection function of the main protection relay device which is arranged at both terminals of the transmission line to be protected and can transmit information is lost. The present invention relates to a ground fault protection relay system that protects a power transmission line.

  The power transmission line is provided with a protective relay system for removing the accident section and minimizing the power outage range when an accident occurs due to a natural disaster or equipment deterioration. This protection relay system is composed of a main protection relay device and a backup protection relay device for when the main protection relay device is not operating or not in use. A ground fault direction relay device (DG relay) is widely used as an electric device.

  As a main protection relay device, for example, a PCM current differential protection relay device (PCM relay) capable of detecting an accident occurring in the system with high sensitivity and accurately calculating the accident section is known. Yes. Moreover, a ground fault direction relay apparatus determines a ground fault direction based on a zero phase voltage and a zero phase current, and selectively interrupts a ground fault distribution line. This ground fault direction relay device can only determine the direction of the ground fault and cannot measure and determine the distance to the fault point. The failure section is selectively cut off.

By the way, when the main protection relay device loses the main protection function, such as when only one main protection relay device is installed, the transmission line in which the main protection relay device is installed is used. The power transmission line must be protected only by a ground fault direction relay device as a backup protection relay device as follows. That is, in the power transmission system shown in FIG. 14, two lines are adjacent to each other between the own end (A end, zero-phase power supply end) and the opposite end (B end) where an electric station (not shown) is installed. Transmission lines 101L and 102L are laid. Further, an instrument transformer (not shown) for stepping down the transmission voltage for measurement is provided on the own end side, and the transmission currents 101L and 102L on the own end side are reduced for measurement. Cut off the transmission lines 101L and 102L so that the influence of the accident does not expand according to the instructions of the current transformers CT _A101 and CT _A102 , the protective relay devices 300A and 600A that detect an accident, and the protective relay devices 300A and 600A Circuit breakers CB _A101 and CB _A102 are provided. Here, the protective relay device 300A is composed of the main protective relay device 100A and the ground fault direction relay device 200A, and the protective relay device 600A is composed of the main protective relay device 400A and the ground fault direction relay device 500A. It is configured. Moreover, you may make the main protection relay apparatus 100A and the main protection relay apparatus 400A into one body.

Similarly, an instrument transformer (not shown), current transformers CT _B101 and CT _B102 , protective relay devices 300B and 600B, and circuit breakers CB _B101 and CB _B102 are provided at the opposite ends. . Here, since the self-end and the opposite end are configured in the same manner, and the power transmission line 101L and the power transmission line 102L are configured in the same manner, the protective relay that mainly protects the power transmission line 101L on the self-end side will be described below. The apparatus 300A will be described.

  In this earth fault direction relay device 200A, as shown in FIG. 15, the determination is made based on the relay elements P11 to P13 and the operation time limit timers 64VT and 67GT, and the earth fault protection of the own section transmission line is performed. A basic circuit is provided. That is, the first relay element P11 outputs a logical value “1” when a zero-phase voltage is detected from the accident detection relay (FD relay) when an accident occurs in the power transmission line 101L. The second relay element P12 is a ground fault overvoltage relay that detects a ground fault in the system, and outputs a logical value “1” when a zero-phase voltage is detected. The third relay element P13 is a ground fault direction relay that detects a ground fault in the opposite terminal direction, and outputs a logical value “1” when a ground fault is detected. The operation time timer 64VT is a timer for time cooperation, and the operation time timer 67GT is a timer for preventing malfunction.

The accident on the zero-phase power supply end side is counted for a predetermined time by the operation time timer 64VT, and is input to the AND gate E11 with a delay. For this reason, as shown in FIG. 16, the breaker CB _A101 on its own end (zero-phase power supply end side) is “Ry determination time + expiration time of operation time limit timer 64VT + expiration time of operation time limit timer 67GT + CB _A101 interruption. It shuts off at "time", that is, it is turned off (open circuit).

  In this way, in the case of an accident on the zero-phase power supply end side, the predetermined time is counted by the operation time timer 64VT, and the operation time timer 64VT is accumulated for each section as shown in FIG. Accident removal time was delayed and prolonged, and the impact on the system could be increased. On the other hand, if the time period counted by the operation time limit timer 64VT is shortened, there is a possibility that it will operate before the relay that should operate originally due to an accident in the next section. In such a case, the power failure range is minimized. There was a risk that a power outage would occur over a wide area.

  On the other hand, a technique is known in which an operating condition of a protection relay that detects an accident in the opposite bus direction is transmitted, and a circuit breaker is interrupted by a transfer signal from the opposite end and the operation of the own-end protection relay (for example, , See Patent Document 1).

Japanese Patent Laid-Open No. 05-076134

  However, in the technique described in Patent Document 1, since the transfer signal is output only during the relay operation, in the case of series interruption in the balanced two lines, the own end performs the relay operation after the other end performs the preceding operation, so this function is There is a possibility that it will not operate, and in the case of a three-terminal system, there is a risk that it will not operate.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a ground fault protection relay system capable of removing a ground fault accident at high speed even when the main protection function of the main protection relay device is lost. And

  In order to solve the above-mentioned problem, the invention of claim 1 is the case where the main protection function of the main protection relay device that is disposed at both terminals of the parallel two-line transmission line and can transmit PCM information is lost. In the ground fault protection relay system that protects the power transmission line by the ground fault direction relay device arranged in each power transmission line, the ground fault direction relay device detects a ground fault and then performs a predetermined time limit. After the elapse of time, the PCM information includes the first break command means for outputting a break command to the circuit breaker of the own terminal and the ground fault detection information indicating that the ground fault has been detected. Information transmitting means for transmitting to the main protective relay device of the opposite terminal from the PCM information transmitted from the main protective relay device of the opposite terminal to the main protective relay device of the own terminal, from the ground fault direction of the opposite terminal Information acquisition means for acquiring the ground fault detection information of the relay device, and the own terminal When a ground fault is detected and the ground fault detection information is acquired by the information acquisition means, or a ground fault accident is detected at its own terminal, and the ground fault detection information is acquired by the information acquisition means In addition, when a ground fault is not detected in the power transmission line adjacent to the own terminal, the second interruption command means for reducing the predetermined time period and outputting the interruption command to the breaker of the own terminal is provided. It is characterized by that.

  According to the present invention, when a ground fault is detected at its own terminal, the first cutoff command means outputs a cutoff command to the breaker at its own terminal after a predetermined time period has elapsed. When a ground fault is detected at the own terminal, ground fault detection information is transmitted from the main protective relay device at the own terminal to the main protective relay device at the opposite terminal by the information transmitting means. Then, when a ground fault is detected at the own terminal and the ground fault detection information of the ground fault direction relay device of the opposite terminal is acquired by the information acquisition means, the predetermined time limit is reduced by the second cutoff command means Then, a break command is output to the breaker at its own terminal. That is, when the ground fault direction relay device operates at the self-terminal and the counter terminal, the circuit breaker of the self-terminal is instantaneously cut off. In addition, a ground fault is detected at the own terminal, and the ground fault detection information of the ground fault direction relay device at the opposite terminal is not acquired by the information acquisition means, and the ground fault is detected at the power transmission line adjacent to the own terminal. Is not detected, the predetermined time limit is reduced by the second shut-off command means, and the shut-off command is output to the breaker at its own terminal. That is, when the ground fault direction relay device operates at its own terminal, the ground fault direction relay device does not operate at the opposite terminal, and the ground fault direction relay device of the power line adjacent to its own terminal does not operate. The breaker at its own terminal is shut off instantaneously.

  According to a second aspect of the present invention, in the ground fault protection relay system according to the first aspect, the ground fault detection information can be acquired by the information acquisition means continuously for a predetermined time. .

  According to a third aspect of the present invention, in the ground fault protection relay system according to the first or second aspect, the second cutoff command means operates only when the two transmission lines are operated in parallel. It is characterized by that.

  According to the first aspect of the present invention, when the ground fault direction relay device is operated at the own terminal and the opposite terminal, it is determined that the own line fault (cooperation with the next section relay is unnecessary) and the own terminal is instantaneously provided. The circuit breaker of is interrupted. In addition, when the ground fault direction relay device operates at its own terminal, the ground fault direction relay device does not operate at the opposite terminal, and the ground fault direction relay device of the transmission line adjacent to its own terminal does not operate. Is determined to be a power supply near-end accident, and the breaker at its own terminal is immediately shut off. For this reason, even when the main protection function of the main protection relay device is lost, it becomes possible to remove the ground fault accident at high speed and reliably, and the protection reliability of the transmission line is increased. Further, since the ground fault detection information is transmitted and received using the main protection relay device, it is not necessary to separately provide a communication device, and the system construction is facilitated.

  According to the invention of claim 2, since the ground fault detection information can be acquired continuously for a predetermined time, the operation timing of the ground fault direction relay device of the own terminal and the operation timing of the ground fault direction relay device of the opposite terminal Even in the case of a deviation, it is possible to reliably acquire the ground fault detection information and determine that the own line accident has occurred. As a result, the accident can be more reliably removed.

  According to the invention of claim 3, since the second shut-off command means is activated only when the two power transmission lines are operated in parallel, that is, the breaker at its own terminal is shut off at high speed. Therefore, it is possible to appropriately perform high-speed shut-off by appropriately making the above determination.

It is a systematic diagram which shows the power transmission system to which the ground fault protection relay system which concerns on embodiment of this invention is applied. It is a schematic block diagram of a ground fault direction relay apparatus in the system of FIG. It is a block diagram of the PCM transmission system in the system of FIG. It is an operation | movement sequence diagram of the ground fault direction relay apparatus in the system of FIG. It is explanatory drawing which shows the interruption | blocking time of the circuit breaker of the power transmission system by the system of FIG. It is a figure (a) which shows operation of the conventional system, and a figure (b) which shows operation of the system of Drawing 1 when a power transmission line accident occurs in the B terminal near end of a 2 terminal system. It is a figure (a) which shows operation of the conventional system at the time of a power transmission line accident having occurred at the A end near 2 terminal system, and a figure (b) showing the operation of the system of FIG. It is a figure (a) which shows operation of the conventional system when a transmission line accident occurs in AB middle part of a 3 terminal system, and a figure (b) showing operation of the system of Drawing 1. It is a figure which shows the continuation of FIG. It is a figure (a) which shows operation of the conventional system at the time of a power transmission line accident having occurred at the B end very near end of a 3 terminal system, and a figure (b) showing operation of the system of Drawing 1. It is a figure which shows the continuation of FIG. FIG. 2A is a diagram illustrating the operation of a conventional system and FIG. 1B is a diagram illustrating the operation of the system of FIG. 1 when a transmission line accident occurs at the closest end of the A terminal of the three-terminal system. It is a figure which shows the continuation of FIG. It is a systematic diagram which shows the power transmission system to which the conventional protection relay system is applied. It is an operation | movement sequence diagram of the ground fault direction relay apparatus in the system of FIG. It is explanatory drawing which shows the interruption | blocking time of the circuit breaker of the power transmission system by the system of FIG. It is a figure which shows the state in which the interruption | blocking time of FIG. 16 is accumulated.

  The present invention will be described below based on the illustrated embodiments.

FIG. 1 is a system diagram showing a power transmission system to which a ground fault protection relay system according to an embodiment of the present invention is applied. This ground fault protection relay system is a main protection relay device 1 _A1 , 1 _A2 , 1 _B1 , 1 _B2 that is disposed at both terminals of two parallel transmission lines L1 and L2 and can transmit PCM information. When the function is lost (when the communication function is maintained), the power transmission lines are transmitted by the ground fault direction relay devices 2 _A1 , 2 _A2 , 2 _B1 , 2 _B2 arranged in the respective power transmission lines L1, L2. This is a protective relay system having a function of protecting L1 and L2.

Here, in the power transmission system, two lines are adjacent to each other in parallel and in parallel between the own end (A end, zero phase power supply end) where the electrical station (not shown) is installed and the opposite end (B end). Power transmission lines L1 and L2 are laid. Further, an instrument transformer (not shown) is provided on the own end side to step down the transmission voltage for measurement. Furthermore, the self-side transmission lines L1 and L2 include current transformers CT _A1 and CT _A2 that reduce the transmission current for measurement, and a protective relay device 3 _A1 that detects an accident or the like when an accident occurs. 3 _A2 and circuit breakers CB _A1 and CB _A2 are provided to cut off the transmission lines L1 and L2 so that the influence of the accident does not expand according to instructions of the protective relay devices 3 _A1 and 3 _A2 . Here, the protective relay device 3 _A1 is configured by the main protective relay device 1 _A1 and the ground fault direction relay device 2 _A1 , and the protective relay device 3 _A2 is configured by the main protective relay device 1 _A2 and the ground fault direction. It is comprised by relay device 2 _A2 . Further, adjacent ground fault direction relay devices 2 _A1 and 2 _A2 are connected to each other so as to be able to communicate with each other, so that their operation states (detection states) can be known from each other as will be described later.

Similarly, an instrument transformer (not shown), current transformers CT _B1 and CT _B2 , and protective relay device 3 _B1 (main protective relay device 1 _B1 and ground fault direction relay device 2 are provided at the opposite ends. _{B1), 3 B2} (primarily a protective relay device _{1 B2} and ground direction relay device _{2 B2),} provided a breaker _CB B1, _{CB B2} is.

As described above, the self-end and the opposite end are configured in the same manner, and the power transmission line L1 and the power transmission line L2 are configured in the same manner. Therefore, in the following, the power transmission line L1 is mainly protected on the self-end side. The protection relay device _3A1 will be described, and the description of the protection relay devices _3A2 , _3B1 , _3B2 will be omitted.

The main protection relay device 1 _A1 sets the power transmission line L1 as a protection section and performs a main protection operation. That is, the current instantaneous value of each terminal is sampled at a constant period, and the obtained digital data (PCM information) is transmitted to the other end by PCM transmission. Then, a differential operation is performed based on the received data and the self-end data, it is determined whether the failure is internal or external, a cut-off signal is output, and the breaker CB _A1 is cut off.

Ground fault direction relay device 2 _A1 determines ground direction based on the zero-phase voltage and zero-phase current, when it is determined that the own line direction of the accident, to the circuit breaker CB _A1 after a predetermined time period has elapsed A cutoff signal, which is an instruction to turn off (open circuit), is sent to prevent the influence of an accident from occurring from expanding. This ground fault direction relay device 2 _A1 can only determine the direction of the ground fault and cannot measure or determine the distance to the fault point. Therefore, the time limit is accumulated from the end toward the zero-phase power supply end. The basic principle is to select and block failure sections in cooperation. Here, the ground fault direction relay device 2 _A1 the own end side of the main protective relay device 1 _A1 is not the operation of the power transmission lines L1, protects the own section transmission line at the time of non-use, also outside the protected Protective relay device for a certain next section transmission line, when the protective relay device installed in the next section transmission line on the opposite end side is non-operational, and a breaker for the next section transmission line on the opposite end side Functions as a backup protection that protects the next section transmission line as a backup.

The ground fault direction relay device 2 _A1, as shown in FIG. 2, the input transducer 21, an analog input processing unit 22, an information transmission section (information transmitting means) 23, the information acquisition unit (information acquiring means) 24 and a calculation output unit (first cutoff command means, second cutoff command means) 25 and the like. The input converter 21 receives the measurement voltage from the instrument transformer and the measurement current from the current transformer CT _A1 , performs A / D conversion on the analog input processing unit 22, and outputs the result to the calculation output unit 25.

Information transmitting unit 23, a ground detection information indicating the detection of ground faults in the own terminal included in the PCM data, the main protective relay device of the opposite terminal from the main protective relay device 1 _A1 of its own terminal 1 _B1 To send to. More specifically, when a ground fault direction relay device 2 _A1 of the own terminal has detected a ground fault in operation, according to the instruction from the operation output unit 25 as described later, preliminary data area of the PCM transmission format The ground fault detection information is input to (for example, control (1)). As a result, as shown in FIG. 3, the transmission device 4 _A1 of the main protective relay device 1 _A1 of its own terminal is connected to the transmission device 4 _B1 of the main protective relay device 1 _B1 of the opposite terminal via the transmission line 4. PCM information including the fault detection information is transmitted.

From the PCM information transmitted from the main protective relay device 1 _B1 of the opposite terminal to the main protective relay device 1 _A1 of the own terminal, the information acquisition unit 24 detects the ground of the ground fault direction relay device 2 _B1 of the opposite terminal. This is to acquire the fault detection information. Specifically, as shown in FIG. 3, the PCM information transmitted from the transmission device 4 _B1 of the main protection relay device 1 _{B1 at} the opposite terminal to the transmission device 4 _A1 of the main protection relay device 1 _A1 at its own terminal by searching the earth fault detection information is stored in a predetermined preliminary data area among acquires ground detection information earth fault direction relay device 2 _B1 opposing terminal. When the ground fault detection information is acquired, a logical value “1” is output to the calculation output unit 25.

If the calculation output unit 25 detects an accident that has occurred on its own end and determines that the operating condition is satisfied, it outputs a break signal to the breaker CB _A1 . As shown in FIG. 4, the calculation output unit 25 outputs a trip command to the circuit breaker CB _A1 of its own terminal after a predetermined time has elapsed since an accident was detected based on the relay elements P1 to P6 and the relay elements P1 to P6. Operation time timers 64VT, 67GT, 67GT0, 67GT1 for outputting (shutoff command), and gates E1-E7 for determining predetermined operation conditions are provided. That is, the calculation output unit 25 determines the success or failure of the operation condition based on the relay elements P1 to P6 and the operation time timers 64VT, 67GT, 67GT0, and 67GT1, and performs ground fault protection for the own section transmission line. Basic circuit.

  The first relay element P1 is an accident detection relay (FD relay), and outputs a logical value “1” when a zero-phase voltage is detected when an accident occurs in the system. The output of the first relay element P1 is applied to AND gates E1 and E7.

  The second relay element P2 is a ground fault overvoltage relay that detects a ground fault in the system, and outputs a logical value “1” when a zero-phase voltage is detected. The output of the second relay element P2 is applied to the AND gate E2 via AND gates E1 and E6 and an operation time limit timer 64VT.

  The third relay element P3 is a ground fault direction relay that detects a ground fault in the opposite terminal direction, and outputs a logical value “1” when a ground fault is detected. The output of the third relay element P3 is applied to AND gates E1, E2, and E6.

The fourth relay element P4 outputs a logical value “1” when performing high-speed shut-off described later, and the output of the fourth relay element P4 is applied to the AND gate E6. Here, the high-speed cutoff is performed only when the transmission lines L1 and L2 are operated in parallel in two lines, and when one of them is cut off, the high-speed cutoff is performed. Not performed. Therefore, when the PCM information is received from the opposite terminal and the “OFF” information (breaking information) of the breaker CB _B1 of the opposite terminal is acquired, the high-speed interruption is not performed, and the fourth relay element P4 The value “0” is output. In other words, the logical value “1” is output if the “OFF” information of the breaker CB _{B1 at} the opposite terminal is not acquired.

Relay element P5 in the fifth, when the ground fault detection information earth fault direction relay device 2 _B1 opposing terminal by the information acquisition unit 24 is acquired, that is, the earth in the ground fault direction relay device 2 _B1 opposing terminal When a fault is detected, a logical value “1” is output. In the case of multi-terminal system, when detecting one of the opposing ground fault direction relay device ground fault in 2 _B1 terminal, and outputs a logical value "1". The output of the fifth relay element P5 is applied to the OR gate E5 via the NOT OR gate E4 and the operation time limit timer 67GT1.

Relay element P6 of the sixth, when a ground fault direction relay device 2 _A2 adjacent the local end detects a ground fault in operation, and outputs a logical value "1". The output of the sixth relay element P6 is applied to the not-or gate E4.

  The operation time timer 64VT is a timer for time cooperation, and starts counting the operation time when the logical value “1” of the second relay element P2 is input. When the count of the predetermined time expires, a logical value “1” is output and added to the AND gate E2.

  The operation time timer 67GT is a timer for preventing malfunction, and starts counting the operation time when the logical value “1” of the AND gate E2 is input. When the count of the predetermined time expires, a logical value “1” is output and added to the OR gate E3.

  When the logic value “1” of the fifth relay element P5 is input, the operation time timer 67GT1 starts counting the operation time. The logical value “1” is output and added to the OR gate E5 until the count for a predetermined time expires. In other words, the operation time limit timer 67GT1 takes a detection signal from the fifth relay element P5 into a predetermined value in order to surely perform a high-speed shut-off process described later in consideration of the PCM transmission time and the processing time of the calculation output unit 25. Hold for time and add to OR gate E5. In this way, the ground fault detection information from the opposing terminal can be continuously acquired and held for a predetermined time. Here, the expiration time of the operation time limit timer 67GT1 is set so that the high-speed interruption condition can be reliably determined by the ground fault direction relay device 2 of each terminal in a three-terminal system described later.

  The operation time timer 67GT0 starts counting the operation time when the logical value “1” of the AND gate E6 is input. When the count of the predetermined time expires, a logical value “1” is output and added to the OR gate E3. That is, the operation time timer 67GT0 performs time cooperation so that the finishing time becomes a predetermined time in consideration of transmission delay and the like.

  When the logical value “1” of the relay elements P1, P2, and P3 is input, the AND gate E1 satisfies the operation condition and outputs the logical value “1”. Thereby, a command to transmit ground fault detection information is output to the information transmission unit 23.

  When the operation time limit timer 64VT expires and the logical value “1” is input, and the logical value “1” of the third relay element P3 is input to the AND gate E2, the operation condition is satisfied and the logical value “1” is satisfied. Is output to the operation time limit timer 67GT.

  When the operation time limit timer 67GT or the operation time limit timer 67GT0 expires and the logical value “1” is input, the OR gate E3 outputs the logical value “1” when the operation condition is satisfied, and adds it to the AND gate E7. It has become.

  When the logical value “1” is not input from either of the relay elements P5 and P6, the not-or gate E4 outputs the logical value “1” when the operating condition is satisfied, and adds it to the OR gate E5.

  The logical value “1” is input to the OR gate E5 until the operation time limit timer 67GT1 expires, or when the logical value “1” of the NOT OR gate E4 is input, the operation condition is established and the logical value “1” is satisfied. Is output to the AND gate E6.

  When the logical value “1” of the relay elements P2, P3, and P4 is input to the AND gate E6 and the logical value “1” of the OR gate E5 is input, the operating condition is satisfied and the logical value “1” is output. The operation time limit timer 67GT0 is added.

When the logical value “1” of the first relay element P1 is input to the AND gate E7 and the logical value “1” of the OR gate E3 is input, the operating condition is satisfied and the interruption signal (trip) to the circuit breaker CB _A1 is established. Command).

  Here, the circuit breaker condition in which the logical value “1” is output from the OR gate E3 is, first, when the relay elements P2 and P3 operate and the operation time timers 64VT and 67GT expire as in the conventional case. In other words, when the operation time timer 67GT expires and the logical value “1” is output from the OR gate E3, a shut-off command is issued to the breaker at its own terminal after a predetermined time period has elapsed since the detection of the ground fault at its own terminal. First shut-off command means for outputting is configured.

Further, the case where the operation time timer 67GT0 expires and the logical value “1” is output from the OR gate E3 is as follows. First, as the first high-speed cut-off condition, when the relay element P5 in the fifth is operated, i.e., is a case of acquiring a ground fault sensing information of the opposite ground direction relay device 2 _B1 terminal by the information acquisition unit 24 . Further, the second quick interruption condition, when the relay element P5, P6 does not operate any, that is, without acquiring the earth fault detection information earth fault direction relay device 2 _B1 opposing terminal by the information acquisition unit 24, and a case where the ground fault direction relay device 2 _A2 adjacent the local end does not work.

When such a high speed cutoff condition is satisfied, a logical value “1” is output from the OR gate E3, and the circuit breaker CB _A1 is shut off at high speed without waiting for the time limit coordination of the operation time limit timer 64VT. That is, when the operation time timer 67GT0 expires and the logical value “1” is output from the OR gate E3, a ground fault is detected at its own terminal, and the ground fault detection information is acquired by the information acquisition unit 24 (When the first high-speed shut-off condition is satisfied) or a ground fault is detected at the own terminal, and the ground acquisition information is not acquired by the information acquisition unit 24, and the transmission line L2 adjacent to the own terminal is also acquired. does not detect a ground fault in the (second high-speed switch condition holds,), a second shutoff means for outputting a cutoff command to the circuit breaker CB _A1 of the own terminal by reducing the predetermined time period (quick interruption processing) Is configured.

Specifically, as shown in FIG. 1, when the accident point is an intermediate point at the AB end, the relay elements P1 to P3 operate at both the own terminal and the opposite terminal, and the fifth relay element of the own terminal P5 also operates. As a result, the first high-speed cutoff condition is established, and the logical value “1” is output from the AND gate E6, so that the circuit breaker CB _A1 is shut off at high speed. As a result, as shown in FIG. 5, the breaker CB _A1 on the own end side is cut off only by “Ry determination time + operation time limit timer 67GT0 + CB _A1 cut-off time”. Similarly, at the opposite terminal, the first high-speed breaking condition is established and the breaker CB _B1 is shut off at high speed. As a result, as shown in FIG. 5, the circuit breaker CB _B1 at the opposite terminal is also cut off only by “Ry determination time + operation time limit timer 67GT0 + CB _B1 cut-off time”. As a result, the fault current does not flow in the line that is not the fault line (the transmission line 2L).

Next, the effect | action of the ground fault protection relay system of such a structure and the protection method of the power transmission line by a ground fault protection relay system are demonstrated. Here, the main protection functions of the main protection relay devices 1 _A1 , 1 _A2 , 1 _B1 , 1 _B2 are lost, but the communication function is maintained. Moreover, although simplified in FIGS. 6-13, the structure in each terminal and each power transmission line is equivalent to the above. Furthermore, the operation order of the local fault direction relay device 2 and the circuit breaker CB differs depending on the system, the fault current at the time of the fault, and the impedance, and an example will be described below.

As shown in FIG. 6, when an accident occurs near the B end (opposite end) of the power transmission line L1 (b-1), for example, the ground fault direction relay device 2 _A1 , 2 _A2 at the A end (own end) And the ground fault direction relay device 2 _B1 at the B end operates (2 of b), and the logical value “1” is output from each of the relay elements P1 to P3, and the operation time timer 64VT is counted. At the same time, the operating condition of the AND gate E1 is established, a logical value “1” is output, and a command to transmit ground fault detection information is output to the information transmitting unit 23. As a result, the ground fault detection information indicating that a ground fault has been detected is transmitted from the main protective relay devices 1 _A1 and 1 _A2 at the A end to the main protective relay devices 1 _B1 and 1 _B2 at the B end. , The main protection relay device 1 _B1 at the B end is transmitted to the main protection relay device 1 _A1 at the A end.

Then, in the ground fault direction relay device 2 _A1 at the A end and the ground fault direction relay device 2 _B1 at the B end, the logic value “1” is output from the fifth relay element P5 and the operating condition of the AND gate E6 ( When the first high-speed cutoff condition) is satisfied, a logical value “1” is output, and the operation time limit timer 67GT0 expires, the operation condition of the AND gate E7 is satisfied. As a result, cut-off signal to the circuit breaker _CB A1, _{CB B1} is transmitted, the circuit breaker _CB A1, _{CB B1} of the transmission line L1 in the A end and B end, without waiting for the count of the operation time limit timer 64VT, "Ry determination Time + operation time limit timer 67GT0 + CB cutoff time "(b-3). On the other hand, the ground fault direction relay device 2 _A2 of transmission line L2, in the ground fault direction relay device 2 _B2 are inactive and B end (opposite end), ground fault direction relay device 2 of the adjacent transmission lines L1 _A1 Therefore, the operating condition of the not-or gate E4 is not satisfied, and the circuit breaker CB _A2 of the transmission line L2 is not cut off. Similarly, the ground fault direction relay device 2 _B2 of the transmission line L2, since the ground fault direction relay device 2 _B2 of its own ends (B end) is not operating, the operating conditions of the AND gate E6 is not satisfied, feed The circuit breaker CB _B2 of the electric wire L2 is not interrupted. Here, after the circuit breakers CB _A1 and CB _B1 are cut off, the fault current does not flow through the transmission line 2L, so the ground fault direction relay device 2 _A2 becomes inoperative.

In this way, the circuit breakers CB _A1 and CB _B1 are both interrupted at high speeds at the A end and B end of the transmission line L1, and the accident is removed at high speed (for example, within 200 ms) (b-4). On the other hand, in the conventional system, as shown in FIG. 6A, the circuit breaker CB _B1 is shut off after the operation time limit timers 64VT and 67GT expire at the B end, and then the operation time limit timer 64VT at the A end. Since the circuit breaker CB _A1 is cut off after 67GT expires, it takes a long time (for example, time within 1000 ms) to remove the accident.

Similarly, as shown in FIG. 7, if an accident near the end A of the transmission line L1 is generated (7 1), for example, only the ground direction relay device 2 _A1 of the A-end is operated, the B end The ground fault detection information is transmitted to the ground fault direction relay device 2 _B1 (2 of 7). In the ground fault direction relay device 2 _A1 at the A end, the ground fault detection information is not transmitted from the ground fault direction relay device 2 _B1 at the B end, which is the opposite end, and the ground fault direction adjacent to the A end Since relay device 2 _A2 does not operate, the operating condition (second high-speed interruption condition) of not-or gate E4 is established, and breaker CB _A1 is interrupted at high speed (3 of 7).

Thereafter, the ground fault direction relay device 2 _B1 at the B end and the ground fault direction relay device 2 _A2 of the power transmission line L2 at the A end operate (4 of 7). In the B-end ground fault direction relay device 2 _B1 , since the ground fault detection information from the A-end ground fault direction relay device 2 _A1 is held by the operation time limit timer 67GT1, the fifth relay element P5 The logical value “1” is maintained and the operating condition of the AND gate E6 (first high-speed interruption condition) is established, and the circuit breaker CB _B1 is interrupted at high speed (5 of 7). Thus, the circuit breakers CB _A1 and CB _B1 are shut off at high speed (for example, within 400 ms) at the A and B ends of the transmission line L1, and the accident is removed.

As described above, according to the ground fault protection relay system, when the ground fault direction relay devices 2 _A1 and 2 _B1 operate at the own terminal and the opposite terminal, it is an own line fault (cooperation with the next section relay). It is determined that it is unnecessary) and the breaker CB _A1 of its own terminal is instantaneously cut off. Moreover, work is ground fault direction relay device 2 _A1 with the own terminal does not operate a ground fault direction relay device 2 _B1 is at the opposite terminal, moreover, the self-terminal of the adjacent transmission lines L2 ground direction relay device for 2 When _A2 does not operate, it is determined that the power supply close end accident has occurred, and the breaker CB _A1 at its own terminal is instantaneously cut off. For this reason, even if the main protection function of the main protection relay devices 1 _A1 , 1 _A2 , 1 _B1 , 1 _B2 is lost, it becomes possible to remove the ground fault at high speed and surely. The protection reliability of L1 and L2 increases. The main protective relay device _{1 A1, 1 A2, 1 B1} , 1 for transmitting and receiving ground fault detection information by using the _B2, there is no need to separately provide a communication device, thereby facilitating system construction.

Moreover, because it can obtain the ground fault sensing information for the predetermined period, the operation timing of the earth fault direction relay device 2 _B1 of operation timing and the counter terminal of the ground fault direction relay device 2 _A1 of the own terminal is deviated Even in this case, it is possible to reliably acquire the ground fault detection information and determine that the own line accident has occurred. As a result, the accident can be more reliably removed.

Furthermore, in the case of a power supply near-end accident, there is a risk of disconnection of the two lines. Therefore, when the main protective relay device _1A1 , _1A2 , _1B1 , _1B2 is not used, the ground fault direction relay on the power supply end side the operation timed timer 67GT device 2 _A1 taking coordination with the operation time limit timer 67GT ground fault direction relay device 2 _B1 opposing end, it is necessary to prevent unwanted blocking. For this reason, there has been a system line that needs to change the setting of the operation time timer 67GT even at night or on holidays. However, according to the ground fault protection relay system, such a setting change is required. do not do.

Further, only when the power transmission lines L1 and L2 are operated in parallel, the high-speed shut-off process is performed so that the self-terminal breaker CB _A1 is shut off at high speed. It is possible to perform high-speed shut-off appropriately by properly performing. That is, when only one line of the power transmission line L1 or the power transmission line L2 is operated, the high-speed cutoff process is inappropriate, and such inappropriate high-speed cutoff is not performed.

Such actions and effects can be obtained also in the case of a three-terminal system. For example, as shown in FIGS. 8 and 9, when a ground fault of the transmission line L1 occurs in the middle part of the AB end in the three-terminal system (b-1), for example, first, two ground faults at the A end Direction relay devices 2 _A1 and 2 _A2 operate and detect, and ground fault direction relay devices 2 _B1 and 2 _C1 at the B and C ends operate (2 of b). At this time, the ground fault detection information is transmitted from the ground fault direction relay devices 2 _A1 and 2 _A2 at the A end to the ground fault direction relay devices 2 _B1 , 2 _B2 , 2 _C1 and 2 _C2 at the B end and the C end. The ground fault detection information is transmitted from the B end ground fault direction relay device 2 _B1 to the A end and C end ground fault direction relay devices 2 _A1 and 2 _C1 , and the C end ground fault direction relay is performed. The ground fault detection information is transmitted from the device 2 _C1 to the ground fault direction relay devices 2 _A1 and 2 _B1 at the A and B ends.

Next, at the A end, the B end, and the C end, the ground fault direction relay device 2 of the own terminal operates and the ground fault direction relay device 2 of the opposite terminal operates in the same manner as described above. The first high-speed interruption condition is satisfied, and the breakers CB _A1 , CB _B1 , and CB _C1 are all interrupted at high speed (b-3). Here, the ground fault direction relay device 2 _A2 of A end, quick interruption is not performed because it does not receive a ground fault sensing information from the ground fault direction relay device 2 _B2, 2 _C2 is the opposite end. In this way, high-speed shut-off is performed at both the A-end, B-end and C-end, and accidents are removed at high speed (for example, within 200 ms) (b-4). On the other hand, in the conventional system, as shown in FIGS. 8 (a) and 9 (a), the circuit breakers CB _A1 , until the operation time timers 64VT and 67GT sequentially expire at the B end, C end, and A end, respectively. Since CB _B1 and CB _C1 are not shut off, it takes a long time (for example, time within 1000 ms) to remove the accident.

Similarly, as shown in FIGS. 10 and 11, when an accident occurs in the transmission line L1 near the B end (opposing end) in the three-terminal system (b-1), for example, first, two grounds at the A end The tangential relay device 2 _A1 , 2 _A2 operates and detects, and the ground fault direction relay device 2 _B1 at the B end operates (b-2). At this time, the ground fault detection information is transmitted from the ground fault direction relay devices 2 _A1 and 2 _A2 at the A end to the ground fault direction relay devices 2 _B1 , 2 _B2 , 2 _C1 and 2 _C2 at the B end and the C end. Then, the ground fault detection information is transmitted from the B end ground fault direction relay device 2 _B1 to the A end and C end ground fault direction relay devices 2 _A1 and 2 _C1 .

Next, the first high-speed cutoff condition is established at the A-end and the B-end, and the breakers CB _A1 and CB _B1 are both shut off at high speed (b-3). Here, the ground fault direction relay device 2 _A2 of A end, Fast trip is not performed for the ground fault direction relay device 2 _B2, 2 _C2 is the opposite end does not receive a ground detection information, the fault current Since it is continuing, it will remain in operation. Subsequently, the C-terminal ground fault direction relay device 2 _C1 operates (4 of b), and the C-end ground fault direction relay device 2 _C1 to the A-end and B-end ground fault direction relay devices 2 _A1 , 2 Ground fault detection information is transmitted to _B1 . Since the ground fault detection information from the A end and the B end is held in the ground fault direction relay device 2 _C1 at the C end, the first high speed breaking condition is satisfied and the breaker CB _C1 is shut off at high speed. (B-5).

In this way, high-speed shut-off is performed at both the A-end, B-end, and C-end, and the accident is removed at high speed (for example, within 400 ms) (b-6). On the other hand, in the conventional system, as shown in FIG. 10 (a) and FIG. 11 (a), the circuit breakers CB _A1 , until the operation time timers 64VT and 67GT sequentially expire at the B end, C end, and A end, respectively. Since CB _B1 and CB _C1 are not shut off, it takes a long time (for example, time within 1000 ms) to remove the accident.

Furthermore, as shown in FIGS. 12 and 13, when an accident occurs in the transmission line L1 near the A end (own end) in the three-terminal system (b-1), for example, first, the ground fault direction connection at the A end is performed. collector _{2 A1} operates and detection (b 2), ground fault direction relay device _{2 A1} from B terminal of the a end and C end ground fault direction relay device _{2 B1, 2 C1} ground fault detection for Information is sent. Next, at the A end, the grounding direction relay device 2 _A1 of the own terminal operates, and the grounding direction relay devices 2 _B1 and 2 _{C1 of} the opposing terminal do not operate and are adjacent to the own terminal. no ground fault direction relay device 2 _A2 of transmission line L2 is operated, since the second high-speed cutoff condition is satisfied, the circuit breaker CB _A1 is high-speed switch that (3 b).

Subsequently, the ground fault direction relay device 2 _A2 at the A end, the ground fault direction relay device 2 _B1 at the B end, and the ground fault direction relay device 2 _C1 at the C end operate (b-4). And in the ground fault direction relay devices 2 _B1 and 2 _C1 at the B end and the C end, since the ground fault detection information from the A end is held, the first high-speed cutoff condition is satisfied and the circuit breaker CB _B1 , CB _C1 is shut off at high speed (b-5).

In this way, high-speed shut-off is performed at both the A-end, B-end, and C-end, and the accident is removed at high speed (for example, within 400 ms) (b-6). On the other hand, in the conventional system, as shown in FIG. 12 (a) and FIG. 13 (a), the circuit breakers CB _A1 , at the A end, B end, and C end respectively, until the operation time timers 64VT and 67GT expire sequentially. Since CB _B1 and CB _C1 are not blocked, it takes a long time to remove the accident. Further, if the operation time timer 67GT on the power supply end side does not coordinate with the operation time limit timer 67GT on the opposite end, the power supply end may cut off two lines, and there is a possibility of a complete power failure.

  Although the embodiment of the present invention has been described above, the specific configuration is not limited to the above embodiment, and even if there is a design change or the like without departing from the gist of the present invention, Included in the invention. For example, in the above embodiment, by providing the operation time limit timer 67GT1, it is possible to continuously acquire and hold the ground fault detection information from the opposite terminal for a predetermined time. However, the information transmission unit 23 detects the ground fault. By transmitting the information continuously for a predetermined time, it may be possible to continuously acquire and hold the ground fault detection information of the other end at the opposite terminal for a predetermined time.

DESCRIPTION OF SYMBOLS 1 Main protection relay apparatus 2 Ground fault direction relay apparatus 23 Information transmission part (information transmission means)
24 Information acquisition unit (information acquisition means)
25 Calculation output section (first shutoff command means, second shutoff command means)
3 Protection relay device P1 1st relay element P2 2nd relay element P3 3rd relay element CT Current transformer CB Breaker A end Own terminal B end, C end Opposing terminal L1, L2 Transmission line 64VT, 67GT, 67GT0, 67GT1 Operation time limit timer

Claims (3)

When the main protection function of the main protection relay device that is disposed at both terminals of the parallel two-line power transmission line and can transmit PCM information is lost, the ground fault direction relay disposed at each of the transmission lines is performed. In a ground fault protection relay system that protects the power transmission line by a device,
The ground fault direction relay device is
A first shut-off command means for outputting a shut-off command to the circuit breaker of the own terminal after a predetermined time period has elapsed since the detection of the ground fault,
Information transmitting means for including ground fault detection information indicating that a ground fault accident has been detected in the PCM information and transmitting from the main protective relay device of the own terminal to the main protective relay device of the opposite terminal;
Information acquisition means for acquiring the ground fault detection information of the ground fault direction relay device of the counter terminal from the PCM information transmitted from the main protection relay device of the counter terminal to the main protection relay device of the own terminal;
When a ground fault is detected at its own terminal and the ground fault detection information is acquired by the information acquisition means, or when a ground fault is detected at its own terminal, and the ground fault is detected by the information acquisition means Second shut-off command means for outputting a shut-off command to the breaker of the self-terminal by reducing the predetermined time when no detection information is acquired and no ground fault is detected in the power transmission line adjacent to the self-terminal When,
A ground fault protection relay system comprising: The ground fault detection information can be acquired by the information acquisition means continuously for a predetermined time.
The ground fault protection relay system according to claim 1. The second shutoff command means is configured to operate only when the power transmission line is operated in two lines in parallel.
The ground fault protection relay system according to any one of claims 1 and 2.

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