JP5361455B2 - Busbar protection relay device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bus protection relay system that shortens a preset lock time to quickly send out motion output even if the motion output is locked during a predetermined time and progressed to an internal accident in a protection area during the lock period due to an external accident occurred in the protection area. <P>SOLUTION: The invention has a motion output stop means 16 and a progress accident detection means 17. The motion output stop means 16 sets the lock time of the motion output by the establishment of an output condition for an accident detection means 14 and an external recognition means 15 to lock the motion output during this lock time. The progress accident detection means 17 starts calculation by the establishment of the output condition for the motion output stop means 16, detects the progress from the external accident to the internal accident, and shortens the lock time. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a bus protection relay device that identifies and identifies an accident that has occurred in an electric power system, and more particularly to a bus protection relay device that has been improved in measures against CT saturation.

  With the progress of digital technology in recent years, bus protection relay devices utilizing digital transmission have become the mainstream in power system protection control systems. In this type of bus protection relay device, each terminal current of the power system is sampled at predetermined time intervals, converted into digital data, and then the occurrence of an accident in the protected area is identified using these digital data. It comes to judge.

  By the way, the busbar protection relay device is provided with a function for preventing malfunction and malfunction from the viewpoint of ensuring reliability. For example, a current differential relay that detects an internal accident with a differential current generated by CT saturation in the event of an external accident may malfunction and output an error. The function of preventing erroneous output due to CT saturation, that is, the CT saturation countermeasure function is one of particularly important functions, and various conventional techniques have been proposed.

  Specifically, in Patent Document 1, an external accident is detected by providing an overcurrent detection relay on the load side of the bus and detecting an overcurrent, and an internal accident is detected by a current differential relay based on this overcurrent detection output. The output is locked for a certain period, which prevents malfunction of the current differential relay.

  Here, a conventional example of a busbar protection relay device having a CT saturation countermeasure function will be described with reference to the block diagram of FIG. This protection method is introduced in Non-Patent Document 1. As shown in FIG. 13, a current data acquisition unit 11, a differential calculation unit 12, a ratio differential calculation unit 13, an accident detection calculation unit 14, and an external determination unit 15 are installed in the bus protection relay device.

  The characteristic configuration in the protection method shown in FIG. 13 is that a timer 10 for locking the output is provided after the accident detection output from the accident detection calculation means 14 and the external discrimination output from the external discrimination means 15. In the point. The timer 10 is configured to reliably continue the output lock for a preset timer value once an external accident is detected. In general, the timer value is often set to about 3 cycles, and Non-Patent Document 2 also describes that fact.

The current data acquisition means 11 is a part that performs digital conversion after sampling the analog electricity quantity of the power system at a predetermined time interval. The differential calculation means 12 is a part that calculates the absolute value of Id, which is the amplitude value of the operation amount shown by the following formula 1, from all the connected transmission line currents (I ₁ , I ₂ ). .

Furthermore, the ratio differential calculation means 13 is a part for calculating the suppression amount shown in the following mathematical formula 2.

The accident detection calculation means 14 changes the amount of change from all the connected transmission line currents (I ₁ , I ₂ ), specifically, the amount of change Σ (the absolute value of ΔI) comparing the current value with the value one cycle before. It is a part which calculates etc.

The external discriminating means 15 calculates the operation amount change ΔId (see the following Equation 3) and the suppression amount change ΔIr (see the following Equation 4) from all the connected transmission line currents (I ₁ , I ₂ ). This is the part to calculate.

  In the bus protection relay device having the above configuration, with respect to the calculation amount of the differential operation means 12, a predetermined relational expression, for example, a constant K1 or more where the absolute value of the amplitude value Id of the operation amount is the sensitivity value of the bus accident and the like When the following relational expression (for example, the following mathematical expression 5) is established, and the predetermined relational expression (for example, the following mathematical expression 6) is established for the amount calculated by the ratio differential calculation means 13, the protection region It is determined that an internal accident has occurred, and an internal accident detection output is sent out.

  In addition, the accident detection calculation means 14 sends out the accident detection output to the timer 10 when the relational expression shown in the following formula 7 is satisfied with respect to the calculated change amount, and the external discrimination means 15 further calculates As for the quantity, an external discrimination output is sent to the timer 10 when the relational expression shown in the following Expression 8 is satisfied. The timer 10 sends out a lock output for locking the operation output for a predetermined time (3 cycles) set in advance.

  In the bus protection relay device having the CT saturation countermeasure function as described above, even when the differential operation means 12 and the ratio differential operation means 13 malfunction due to CT saturation, the timer 10 performs a predetermined time. The operation output can be locked. For this reason, it is possible to reliably prevent erroneous output of operation output.

JP-A-8-116623

“Protective Relay System Engineering” P196 (published by the Institute of Electrical Engineers of Japan) “The Institute of Electrical Engineers of Japan Technical Report No. 898” P127

  However, the following problems have been pointed out for the busbar protection relay device having the above-described configuration. As already described, when an accident detection output from the accident detection calculation means 14 and an external discrimination output from the external discrimination means 15 are established due to the occurrence of an external accident in the protection area, a predetermined time set by the timer 10, for example, The internal accident detection output will be locked for 3 cycles. For this reason, during the three cycles set by the timer 10, even if an external accident in the protection area progresses to an internal accident, an operation output cannot be sent out. As a result, there has been a problem that the operation output of the busbar protective relay device is delayed.

  The above points will be described in detail with reference to FIGS. FIG. 14 is a bus line configuration diagram, and as shown in this figure, a power line L1 via a bus bar and a circuit breaker CB1 and a power transmission line L2 via a circuit breaker CB2 are connected. FIG. 15 is a response diagram of the output in each part of the bus protection relay device shown in FIG. 13, and the current of each part in the case of progressing to an internal fault of the bus after an accident has occurred outside the bus shown in FIG. 14. It represents the amount of movement. In addition, the operation amount of each part is a current vector sum.

  More specifically, in FIG. 15, (15-a) is the current I1 of the transmission line L1, (15-b) is the current I2 of the transmission line L2, (15-c) is the operation amount, and (15-d) is the figure. 13 shows an internal accident detection output, (15-e) shows an accident detection output in FIG. 13, (15-f) shows an external discrimination output in FIG. 13, (15-g) shows a lock output in FIG. 13, and (15-h) Shows the operation output in FIG.

  As shown in FIG. 15, when both the accident detection output from the accident detection calculation means 14 and the external discrimination output from the external discrimination means 15 are established due to the occurrence of an external accident in the protection area, the timer 10 is reset after the external discrimination output is restored. The internal accident detection output is locked for the set three-cycle period. Therefore, even if the external accident progresses to an internal accident in the protection area during these three cycles, the bus protection relay device cannot send an operation output until the period of the three cycles is completed. Become.

  The present invention has been made to solve the above problems, and even if the operation output is locked for a predetermined time due to the occurrence of an external accident in the protection area, the process progresses to an internal accident in the protection area during this lock period. In this case, an object of the present invention is to provide a busbar protection relay device that can shorten the set lock time and transmit an operation output at a high speed, and further improve the reliability.

In order to achieve the above object, the present invention samples each terminal current of the power system at a predetermined time interval, converts it into digital data, and uses these digital data to identify the occurrence of an accident in the protected area. A ratio differential that determines an internal fault of a bus by a predetermined ratio differential operation by calculating an operation amount and a suppression amount in the protection area using the digital data. The relationship between the calculation means, the accident detection means for detecting an accident in the power system using the digital data, and the ratio between the change in the operation amount and the change in the suppression amount in the protection area using the digital data To an external discrimination means for detecting an external accident in the protection area from the fault detection means and the external discrimination means. Set the lock time of the output, during the locking time, the operating output inhibiting means for locking the operating output, the operation output blocking means calculates started by sending the computed activation output with the passage of the output conditions, the digital data For detecting the progress from an external accident to an internal accident in the protection area from the relationship between the ratio of the change in the operation amount and the change in the suppression amount in the protection area to shorten the lock time. And a progress accident detecting means for sending a lock time shortening output to the operation output blocking means.

  In the present invention having the above-described configuration, when the output condition of the operation output blocking means is satisfied, the progress accident detection means starts calculation and uses the digital data to calculate the amount of change and the amount of suppression in the protection area. The progress from the external accident to the internal accident in the protection area is detected from the relationship with the change, and the lock time shortening output is sent to the operation output blocking means. Thereby, the operation output blocking means sends out the operation output at a high speed before the set lock time. Therefore, after an accident occurs outside the protection area, when an accident further occurs inside the protection area, quick operation output is possible.

  As described above, according to the bus protection relay device of the present invention, even if the operation output is locked for a predetermined time due to the occurrence of an external accident in the protection area, an internal accident in the protection area occurs during this lock period. In the case of progress, the lock time can be shortened to enable high-speed operation output, and the reliability can be improved.

  Hereinafter, embodiments of a busbar protection device according to the present invention will be specifically described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same member in each embodiment, and the same member in the prior art shown in FIGS. 13-15, and the duplication of description is avoided.

(1) First embodiment (configuration)
First, the first embodiment will be described with reference to FIGS. FIG. 1 is a functional block diagram according to the first embodiment. As shown in FIG. 1, the structural feature of the first embodiment is that an operation output blocking means 16 and a progress accident detection means 17 are added to the prior art shown in FIG.

  Among these, the operation output prevention means 16 sends out a calculation start output to the progress accident detection means 17 when the accident detection output from the accident detection means 14 and the external discrimination output from the external discrimination means 15 are established. Further, the lock time is set, and the operation output is locked during the set lock time.

Further, the progress accident detection means 17 is activated by the calculation activation output from the operation output blocking means 16. The computation-driven progress accident detection means 17 takes in the change amount ΔId of the operation amount and the change amount ΔIr of the suppression amount in the protection region, and a predetermined relational expression such as the relational expression shown in the following Expression 9 is taken into these calculation amounts. Is established, the progress from the external accident of the bus to the internal accident is detected, and an output for shortening the lock time is sent to the operation output blocking means 16.

(Function)
The operation of the first embodiment having the above configuration will be described with reference to FIGS. FIG. 2 shows the amount of change in the current, the amount of operation, the amount of operation, the amount of suppression, and the amount of suppression in the case where an accident has occurred outside the bus shown in FIG. .

  More specifically, (2-a) is the current I1 of the transmission line L1, (2-b) is the current I2 of the transmission line L2, (2-c) is the operation amount Id, (2-d) is the suppression amount Ir, (2-e) shows the change amount ΔId of the operation amount, and (2-f) shows the change amount ΔIr of the suppression amount. Note that the operation amount of each unit is a current vector sum, and the suppression amount is a current scalar sum.

  Here, in the external accident in the protection area, the change amount ΔId of the operation amount does not occur, the change amount ΔIr of the suppression amount occurs, and the progress accident detection means 17 does not hold the relationship of the above formula 9, but the protection amount In the internal accident in the region, the change amount ΔId of the operation amount and the change amount ΔIr of the suppression amount are substantially the same, and the relationship of Equation 9 is established. This makes it possible to detect progress from an external accident to an internal accident on the bus.

  FIG. 3 shows the current and operation amount (current vector sum) of each part when an external accident of the bus shown in FIG. The current I1 of the electric wire L1, (3-b) is the current I2 of the transmission line L2, (3-c) is the operation amount, (3-d) is the lock time shortening output in FIG. 1, and (3-e) is FIG. (3-f) is the accident detection output in FIG. 1, (3-g) is the external discrimination output in FIG. 1, (3-h) is the lock output in FIG. 1, and (3-i) is The operation | movement output in FIG. 1 is shown.

  In the case shown in FIG. 3, when the accident detection output from the accident detection calculation means 14 and the external discrimination output from the external discrimination means 15 are established due to the occurrence of an external accident in the protection area, the action output blocking means 16 is set to the action output lock time. To lock the internal accident detection output for a predetermined time.

  Further, the operation output blocking means 16 sends a calculation start output to the progress accident detecting means 17. Here, when the external accident of the busbar progresses to the internal accident of the busbar, the relationship of the formula 9 is established in the progressing accident detection means 17, and the progressing accident detection means 17 sends out the lock time shortening output to the operation output blocking means 16. To do. As a result, the operation output blocking means 16 can shorten the lock time, send the operation output at a high speed without waiting for the preset lock time to end, and appropriately cope with an internal accident.

(effect)
As described above, according to the first embodiment, the operation output blocking means 16 and the progress accident detection means 17 are provided in the configuration of the conventional busbar protection relay device, so that an external accident in the protection area can be prevented. After the occurrence, if a further internal accident occurs in the protection area, the preset lock time can be shortened and high-speed operation output can be performed, and further improvement in reliability can be achieved.

(2) Second embodiment (configuration)
Next, the second embodiment will be described with reference to FIGS. FIG. 4 is a functional block diagram showing a second embodiment of the busbar protection device according to the present invention. The feature of the second embodiment is that a timer 28 is added to the output side of the progress accident detection means 27 with respect to the first embodiment shown in FIG.

  The timer 28 is for confirming that the progress accident detection output sent from the progress accident detection means 27 has continued for a predetermined time or more, and locks the operation output blocking means 16 after the confirmation. A time-reduced output is sent out and the operation output is sent out at high speed. The confirmation time of the timer 28 is set to a period in which the change amount ΔId of the operation amount in the protection area is relatively smaller than the change amount ΔIr of the suppression amount.

  Further, the output sent from the progress accident detection means 17 in the first embodiment is a lock time output to the operation output blocking means 16, whereas the progress accident detection means 27 in the second embodiment. Then, it is comprised so that a progress accident detection output may be sent to the timer 28. FIG.

  That is, the progress accident detection means 27 is activated by the calculation activation output from the action output blocking means 16, takes in the change amount ΔId of the operation amount and the change amount ΔIr of the suppression amount in the protection region, and sets these calculation amounts as predetermined values. When the relationship of Eq. 9, for example, the relationship of Eq. 9 is established, the progress from the external accident of the bus to the internal accident is detected, and the progress accident detection output is sent to the timer 28.

(Function)
The effect | action of said 2nd Embodiment is demonstrated using FIG. 5 and FIG. FIG. 5 shows the amount of change in the current, amount of operation, amount of operation, and amount of suppression when the external accident of the bus shown in FIG. , (5-a) is the current I1 of the transmission line L1, (5-b) is the current I2 of the transmission line L2, (5-c) is the operation amount Id, (5-d) is the suppression amount Ir, (5- e) shows the change amount ΔId of the operation amount, and (5-f) shows the change amount ΔIr of the suppression amount.

  In this case, the non-saturation period of the current transformer CT (the portion surrounded by the dotted lines (5-c) to (5-f) in FIG. 5) is excluded due to the saturation of the current transformer CT in the external accident in the protection area. As a result, the movement amount Id and the movement amount change amount ΔId are generated, and the progress accident detection means 17 establishes the relationship represented by Equation (9). For this reason, a progress accident detection output is sent out in spite of an external accident.

  However, since the timer 28 sets a predetermined period as the confirmation time, the change amount ΔId of the operation amount in the protection area is relatively smaller than the change amount ΔIr of the suppression amount. The lock time shortening output is not sent to the operation output blocking means 16. Accordingly, the operation output lock by the operation output blocking means 16 is continued.

  Thereafter, when an external accident of the busbar progresses to an internal accident of the busbar, the period in which the change amount ΔId of the operation amount and the change amount ΔIr of the suppression amount in the protection area are substantially the same amount continues for a predetermined period. Will do. That is, the relationship represented by Equation 9 is established for a time set in advance by the timer 28 or more. In this way, it is possible to correctly detect the progress to an internal accident without accidentally shortening the lock time in the event of an external accident on the busbar.

  FIG. 6 shows the current and operation amount (current vector sum) of each part in the case where an accident involving saturation of the current transformer CT occurs outside the bus shown in FIG. . That is, (6-a) is the current I1 of the transmission line L1, (6-b) is the current I2 of the transmission line L2, (6-c) is the operation amount Id, and (6-d) is the progress accident detection in FIG. (6-e) is the lock time shortening output in FIG. 4, (6-f) is the internal accident detection output in FIG. 4, (6-g) is the accident detection output in FIG. 4, and (6-h) is the figure. 4 shows an external discrimination output, (6-i) shows a lock output in FIG. 4, and (6-j) shows an operation output in FIG.

  In this case, in the occurrence of an external accident in the protection area, the accident detection output from the accident detection calculation means 14 and the external determination output from the external determination means 15 are established, and the operation output blocking means 16 is activated by the progress accident detection means 27. The output is sent, and the operation output blocking means 16 sets the lock time of the operation output. Here, the internal accident detection output is locked for the time set by the operation output blocking means 16.

  Further, the operation amount Id is generated due to the saturation of the current transformer CT, and the progress accident detection output from the progress accident detection means 27 is established. Even if the progress accident detection output is established, the timer 28 has a predetermined confirmation time. The operation output blocking unit 16 continues to lock the operation output without sending the lock time shortening output to the operation output blocking unit 16.

  After that, when an accident involving saturation of the current transformer CT progresses to an internal accident on the bus, if the relationship expressed by Equation 9 is established in the progress accident detection means 27 for a time set in advance by the timer 28, the timer 28 sends an output for shortening the lock time to the operation output blocking means 16. Upon receiving this output for shortening the lock time, the operation output blocking means 16 can shorten the set lock time and send out the operation output at a high speed to appropriately cope with an internal accident.

(effect)
According to the second embodiment as described above, by providing the timer 28 on the output side of the progress accident detecting means 27 in addition to the configuration of the first embodiment, there are the following effects. That is, as long as the timer value in the timer 28 is valid, the lock time is not shortened for the operation output blocking means 16.

  Therefore, the reliability is improved without accidentally shortening the lock time in the event of an external accident on the busbar. Furthermore, the lock time by the operation output blocking means 16 is shortened only when an accident has occurred outside the protection area and then has progressed to an internal accident in the protection area, thereby reliably preventing erroneous output of the operation output. Can do.

(3) Third embodiment (configuration)
Next, the third embodiment will be described with reference to FIGS. FIG. 7 is a functional block diagram showing a third embodiment of the busbar protection device according to the present invention. Compared with the second embodiment shown in FIG. 4, the third embodiment is characterized in that the operation amount change level detection means 31 is added on the output side of the operation output blocking means 16.

The operation amount change level detection means 31 is activated by the calculation activation output from the operation output blocking means 16, and a predetermined relational expression, for example, the following expression 10 is established for the movement amount change ΔId in the protection region. In this case, the operation amount change level detection output is sent to the AND circuit 32.

  The progress accident detection means 27 is basically the same as that of the second embodiment shown in FIG. In other words, the progress accident detection means 27 takes in the change amount ΔId of the operation amount and the change amount ΔIr of the suppression amount in the protection region, and adds a predetermined relational expression, for example, the above formula 9 (a constant K5 less than 1) to these calculation amounts. This is a part that detects the progress of the bus from an external accident to an internal accident based on the relationship that holds, and sends the progress accident detection output to the timer 28.

  As for the timer 28, when the progress accident detection output from the progress accident detecting means 17 has passed a predetermined time set in advance by the timer 28, the AND circuit outputs the progress accident timer output instead of the lock time shortening output. 32. The AND circuit 32 sends a lock time shortening output to the action output blocking means 16 using the progress accident timer output from the timer 28 and the action quantity change level detection output from the action quantity change level detecting means 31 as output conditions. It is like that.

(Function)
The operation of the third embodiment as described above is as follows (see FIG. 8). FIG. 8 shows the current and operation amount of each part when the circuit breaker CB2 is opened after an accident involving saturation of the current transformer CT occurs outside the bus bar shown in FIG.

  8, (8-a) is the current I1 of the transmission line L1, (8-b) is the current I2 of the transmission line L2, (8-c) is the operation amount Id, and (8-d) is the operation in FIG. (8-e) is the progress accident detection output in FIG. 7, (8-f) is the progress accident timer output in FIG. 7, (8-g) is the lock time shortening output in FIG. -H) is an internal accident detection output in FIG. 7, (8-i) is an accident detection output in FIG. 7, (8-j) is an external discrimination output in FIG. 7, and (8-k) is a lock output in FIG. (8-l) shows the operation output in FIG.

  In the case shown in FIG. 8 above, an external accident occurs in the protection area, the accident detection output from the accident detection calculation means 14 and the external discrimination output from the external discrimination means 15 are established, and the operation output blocking means 16 is a progress accident. A calculation start output is sent to the detection means 27 and the operation amount change level detection means 31, and the operation output blocking means 16 sets an operation output lock time. Here, the operation output is locked during the lock time set by the operation output blocking means 16.

  When the operation amount Id occurs due to the saturation of the current transformer CT, the progress accident detection means 27 establishes the progress accident detection output. However, as in the second embodiment, the progress accident detection means 27 does not send the progress accident timer output to the AND circuit 32 due to the effect of the timer 28. Therefore, the AND circuit 32 does not send the lock time shortening output to the operation output blocking means 16.

  Therefore, the operation output blocking means 16 continues to lock the operation output. Thereafter, when the circuit breaker CB2 is opened, a current close to a DC component flows in the secondary circuit of the current transformer CT depending on the characteristics of the circuit breaker CT and the current transformer CT. , The relationship of Equation 9 is established, and the progress accident timer output from the timer 28 is established.

  However, if the timer 28 is established and the absolute value of the change amount ΔId of the operation amount is not increased, the operation amount change level detection means 31 is not established, so that the operation amount change level detection output is restored. For this reason, the AND circuit 32 does not send the lock time shortening output to the operation output blocking means 16, and the operation output lock time is not shortened.

  That is, after the timer 28 is established, the operation amount change level detection means 31 detects the operation amount change level only after a predetermined relational expression, for example, the relationship of the above-described Expression 10, is established for the change amount ΔId of the operation amount in the protection region. The output is sent to the AND circuit 32. In response to this, the AND circuit 32 sends an output for shortening the lock time to the operation output blocking means 16. As a result, the operation output blocking means 16 shortens the set lock time and sends out the operation output at a high speed, thereby making it possible to appropriately deal with internal accidents.

(effect)
As described above, in the third embodiment, by providing the operation amount change level detecting means 31, even when the circuit breaker is opened in an external accident and the output of the timer 28 is established, the operation amount change If the absolute value of the change amount ΔId of the operation amount detected by the level detection unit 31 does not increase, the lock time shortening output is not sent to the operation output blocking unit 16. That is, the operation time is not sent out by inadvertently raising the lock time due to a slight change in the operation amount. Thereby, in the bus protection relay device having the CT saturation countermeasure function, it is possible to reliably prevent erroneous output of the operation output.

(4) Fourth embodiment (configuration)
Further, a fourth embodiment will be described with reference to FIGS. FIG. 9 is a functional block diagram of the fourth embodiment. As shown in FIG. 9, the feature of the fourth embodiment is that an interruption command detecting means 41 is provided in place of the operation amount change level detecting means 31 in the third embodiment shown in FIG.

  The shut-off command detecting means 41 is a part that takes in a shut-off command from a protective device installed on the accident line in the event of an external accident, and starts the calculation of the progress accident detecting means 27 together with the output of the operation output blocking means 16.

(Function)
The effect | action of the above 4th Embodiment is demonstrated using FIG. FIG. 10 shows the current and operation amount of each part when the circuit breaker CB2 is opened after an accident involving saturation of the current transformer occurs outside the bus shown in FIG.

  10, (10-a) is the current I1 of the transmission line L1, (10-b) is the current I2 of the transmission line L2, (10-c) is the operation amount Id, and (10-d) is the cutoff in FIG. The command detection output, (10-e) is the progress accident detection output in FIG. 9, (10-f) is the lock time shortening output in FIG. 9, (10-g) is the internal accident detection output in FIG. ) Shows the accident detection output in FIG. 9, (10-i) shows the external discrimination output in FIG. 9, (10-j) shows the lock output in FIG. 9, and (10-k) shows the operation output in FIG.

  As shown in FIG. 10, in the fourth embodiment, in an accident outside the protection area, both the accident detection output of the accident detection calculation means 14 and the external discrimination output of the external discrimination means 15 are established, and the operation output blocking means 16 When the operation output lock time is set, the operation output is locked only for the time set by the operation output blocking means 16, and then, from the protection device installed on the accident line by the shutoff command detection means 41. When the interruption command is established, the progress accident detection means 27 starts the calculation.

  Further, even if the operation amount Id occurs due to the saturation of the current transformer CT and the progress accident detection output in the progress accident detection means 27 is established, the lock time shortening output is transmitted for a predetermined period due to the effect of the timer 28. However, the operation output blocking means 16 continues to lock the operation output.

  Thereafter, in the progress accident detection means 27, the relationship represented by Equation 9 is established due to the influence of a current close to a DC component generated on the secondary side of the current transformer CT2 when the circuit breaker CB2 is opened. However, after the circuit breaker CB2 is opened, the breakage command detection output from the breakage command detection means 41 is restored, so that the progress accident detection output from the progress accident detection means 27 is restored.

  Therefore, the timer 28 does not output a lock time shortening output to the operation output blocking means 16. As a result, the operation output blocking means 16 does not shorten the operation output lock time, and no operation output is sent out. That is, in the fourth embodiment, after the breaker CB2 is opened in an external accident, even if the progress accident timer output is established, if the interruption command is detected, the operation output blocking means 16 is locked. There is no time savings.

(effect)
The effects of the fourth embodiment as described above are as follows. That is, by providing the shut-off command detection means 41, after the circuit breaker CB2 is opened in an external accident, the operation output blocking means 16 does not shorten the lock time even if the output in the timer 28 is established. For this reason, it is possible to reliably avoid a malfunction caused by the cutoff command.

(5) Fifth embodiment (configuration)
The basic configuration of the fifth embodiment is the same as that of the fourth embodiment, and the feature thereof is in the shutoff command detection means 51 (see the functional block diagram of FIG. 11). The characteristic of the shut-off command detection means 51 is that the ratio condition between the change amount of the operation amount and the change amount of the suppression amount used for the determination of the progress accident detection means 27 is changed by the output.

  More specifically, the shut-off command detection means 51 in the fifth embodiment captures a shut-off command from a protective device installed in the accident line in the event of an external accident, and detects a progress accident when the shut-off command is output. The relational expression of the means 27 and the value of the constant K5 in the mathematical expression 9 are changed so as to increase in the range of less than 1, for example, from 0.3 to 0.9, and the relation is preset by the timer 28. When the predetermined time is satisfied, the timer 28 sends a lock time shortening output to the operation output blocking means 16.

(Function)
The operation of the fifth embodiment will be described with reference to FIG. FIG. 12 shows the current and operation amount of each part when the circuit breaker CB2 is opened after an accident involving saturation of the current transformer CT occurs outside the bus bar shown in FIG.

  12, (12-a) is the current I1 of the transmission line L1, (12-b) is the current I2 of the transmission line L2, (12-c) is the operation amount Id, and (12-d) is the cutoff in FIG. The command detection output, (12-e) is the progress accident detection output in FIG. 11, (12-f) is the lock time shortening output in FIG. 11, (12-g) is the internal accident detection output in FIG. ) Shows the accident detection output in FIG. 11, (12-i) shows the external discrimination output in FIG. 11, (12-j) shows the lock output in FIG. 11, and (12-k) shows the operation output in FIG.

  In the case shown in FIG. 12, in the case of an accident outside the protection area, the accident detection output of the accident detection calculation means 14 and the external determination output of the external determination means 15 are established, and the operation output lock means 16 sets the operation output lock time. When the operation output is locked for the set time and the shut-off command is detected by the shut-off command detecting means 51 from the protective device installed on the accident line, the calculation of the progress accident detecting means 27 is started. .

  In addition, the shutoff command detection means 51 changes the relational expression in the progress accident detection means 27, for example, the value of the constant K5 in the mathematical expression 9 so as to increase from 0.3 to 0.9, for example, in the range of less than 1. The operation amount Id in the protection region is generated by saturation of the current transformer CT, and the progress accident detection output in the progress accident detection means 27 is established. If the timer value of the timer 28 is valid, the fourth embodiment is performed. As in the embodiment, the operation output blocking means 16 continues to lock the operation output without sending out the lock time shortening output due to the effect of the timer 28.

  Thereafter, when the circuit breaker CB2 is opened, a current close to a direct current component flows in the secondary circuit of the current transformer CT2, and the constant K5 is changed in the progress accident detection means 27 by the influence of this current. As a result, the output condition of the progress accident detection means 27 is not satisfied and the progress accident detection output is restored, so that the timer 28 does not output the lock time shortening output to the operation output prevention means 16 and the operation output prevention means 16. Does not shorten the operation output lock time, and the operation output continues to be locked.

(effect)
According to the above fifth embodiment, similarly to the fourth embodiment, even when the circuit breaker CB is opened in an external accident, the operation output blocking means 16 is not shortened and the error is not shortened. Operation output is not sent.

(6) Other Embodiments The present invention is not limited to the above-described embodiment, and the configuration and the number of arrangement of each member, set numerical values, timer values, and the like can be appropriately changed. The relational expression adopted by the means or the like, that is, the relation of the ratio between the change in the operation amount in the protection area and the change in the suppression amount, etc. can be selected as appropriate.

1 is a functional block diagram of a first embodiment according to the present invention. The wave form diagram of each waveform output at the time of the bus-bar internal progress accident from the bus-bar external accident in 1st Embodiment. FIG. 6 is a response diagram of each output in the first embodiment. The functional block diagram of 2nd Embodiment which concerns on this invention. The wave form diagram of each waveform output at the time of a bus internal progress accident from the bus external accident in 2nd Embodiment. The response diagram of each output in 2nd Embodiment. The functional block diagram of 3rd Embodiment which concerns on this invention. The response diagram of each output in 3rd Embodiment. The functional block diagram of 4th Embodiment which concerns on this invention. The response diagram of each output in 4th Embodiment. The functional block diagram of 5th Embodiment which concerns on this invention. The response diagram of each output in 5th Embodiment. The functional block diagram which shows the structure of the conventional bus-bar protection apparatus. General bus line block diagram. FIG. 14 is a response diagram of each output in the conventional busbar protection device shown in FIG. 13.

DESCRIPTION OF SYMBOLS 10, 28 ... Timer 11 ... Current data acquisition means 12 ... Differential calculation means 13 ... Ratio differential calculation means 14 ... Accident detection calculation means 15 ... External discrimination means 16 ... Operation output prevention means 17, 27 ... Progression accident detection means 31 ... Operating amount change level detection means 32 ... AND circuits 41, 51 ... cut-off command detection means

Claims (5)

This is a bus protection relay device that samples each terminal current of the power system at predetermined time intervals, converts it into digital data, and uses these digital data to identify and determine the occurrence of an accident in the protection area. A ratio differential calculation means for calculating an operation amount and a suppression amount in the protection area using the digital data and determining an internal fault of the bus by a predetermined ratio differential calculation; and the power using the digital data Accident detection means for detecting an accident in the system, and external discrimination for detecting an external accident in the protection area from the relationship between the ratio of the change in the operation amount and the change in the suppression amount in the protection area using the digital data A bus protection relay device having means,
The operation output lock means for setting the operation output lock time by establishing the output condition of the accident detection means and the external determination means, and locking the operation output during the lock time;
The operation output prevention means is activated by the calculation activation output sent out when the output condition is satisfied, and the relationship between the change amount of the operation amount and the change amount of the suppression amount in the protection region using the digital data. And a progress accident detecting means for detecting a progress from an external accident to an internal accident in the protection area and sending a lock time shortening output for shortening the lock time to the operation output blocking means. The bus protection relay device.   The progress accident detection means is to perform the reduction of the lock time after confirming that the ratio of the change in the operation amount and the change in the suppression amount in the protection area has continued for a predetermined time or more. The busbar protective relay device according to claim 1, which is configured.   The progress accident detection means, regarding the shortening of the lock time, in addition to the relationship of the ratio of the change in the operation amount and the change in the suppression amount in the protection region, the change in the operation amount is a predetermined value or more. 3. The bus bar protection relay device according to claim 1, wherein the bus bar protection relay device is configured to be performed under certain conditions. This is a bus protection relay device that samples each terminal current of the power system at predetermined time intervals, converts it into digital data, and uses these digital data to identify and determine the occurrence of an accident in the protection area. A ratio differential calculation means for calculating an operation amount and a suppression amount in the protection area using the digital data and determining an internal fault of the bus by a predetermined ratio differential calculation; and the power using the digital data Accident detection means for detecting an accident in the system, and external discrimination for detecting an external accident in the protection area from the relationship between the ratio of the change in the operation amount and the change in the suppression amount in the protection area using the digital data A bus protection relay device having means,
The operation output lock means for setting the operation output lock time by establishing the output condition of the accident detection means and the external determination means, and locking the operation output during the lock time;
Shut-off command detection means for fetching a shut-off command from a protective device installed in the accident line in the event of an external accident;
The calculation is started when the output condition of the operation output blocking means is satisfied and the output condition of the shut-off command detection means is satisfied, and the change amount of the operation amount and the change amount of the suppression amount in the protection region are calculated using the digital data. A bus protection relay device comprising: a progress accident detection means for detecting a progress from an external accident to an internal accident in the protection area based on a ratio relationship and reducing the lock time.   5. The progress accident detection means is configured to change a condition of a ratio between a change amount of an operation amount for detecting a progress accident and a change amount of a suppression amount by an output of the shutoff command detection means. The busbar protective relay device described in 1.

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