JP2656361B2 - Accident point identification system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Industrial application field) The present invention relates to an accident point identification system that facilitates identification and grasp of an accident point in a power system.

(Prior art) Accelerating the restoration of power system accidents is an important issue. However, with the expansion and complexity of the power system, system accidents have become widespread and diversified, and it is becoming difficult to accurately grasp the location of the accident and perform quick recovery operations.

In other words, at present, the accident location is estimated from limited accident information, such as discrimination between major and minor failures, that summarizes the operation status of circuit breakers, the operation status of protective relays, and the response of protective relays.
The fact is that a recovery operation is being performed.

In particular, if a widespread power failure occurs, the current accident information cannot be used to determine the location of the accident.
Since the location of the accident is determined and the recovery operation is performed, a long time is required for the operation. Further, in the process of recovering from the fact that the location of the accident has not been determined, if there is a permanent accident in the facility, the accident may be further expanded, which is a problem.

(Problem to be Solved by the Invention) The expansion of accident identification with respect to the conventional method described above is summarized as follows.

Since the primary purpose of the protection relay is not to identify accident points, satisfactory results have not always been obtained. For example, in the case where an accident has been eliminated by back-up protection, the range covered by the protection relay is too wide, and it is not easy to identify the accident point.

The installation position of the protection relay CT is closely related to the position of the circuit breaker for the purpose of system protection. Therefore, in the conventional fault point identification based on the response result of the protection relay, the accuracy is limited in units of sections divided by the circuit breaker. In view of the necessity of electric power system maintenance, accident point identification in units of protection sections is insufficient, and more accurate identification is desired.

Technical innovations in current transformers (CTs) provide a clue to the above issues. A CT using the Faraday effect has been developed, compared to a conventional CT using an iron core, and has become practical. When such a small and inexpensive CT becomes practical, the CT can be easily installed at any point regardless of the position of the circuit breaker. Within the premises of an electric substation, the bus can be finely divided irrespective of the switch and circuit breaker installation sections, and CT can be installed at the boundary points. In the case of power transmission lines, it will be possible to install a CT for each tower and transfer current information using an optical fiber attached to an overhead ground wire. In such a situation, the problem of the conventional fault point identification method based on the response result of the protection relay can be easily solved.

The present invention has been made in view of the above circumstances, and has as its object to provide an accident point identification system capable of easily specifying and grasping an accident point.

[Constitution of the Invention] (Means for Solving the Problems) The accident point identification system according to claim 1 of the present invention transmits from a plurality of current transformers installed so as to divide a power system to be protected into a plurality of sections. Introducing means for introducing a detection current of each current transformer through means, setting means for setting a combination of the current transformers so as to partition the power system to be protected into a plurality of protection target sections, First determining means for determining that an accident exists in the section when the sum of the inflow currents to each of the divided sections is not zero using the respective detected currents of the current transformers set by the setting means; When it is determined that an accident exists in a plurality of sections as a result of the first determination means,
If there is an overlapping area between these sections, a second determining means for determining that an accident exists in the overlapping area is provided.

In addition, the fault point identification system according to claim 2 introduces a detection current of each current transformer through a transmission means from a plurality of current transformers installed so as to divide the power system to be protected into a plurality of sections. Means, setting means for setting a combination of the current transformers so as to partition the power system to be protected into a plurality of protection target sections, and each detected current of the current transformers set by the setting means. A first judging means for judging that an accident exists in the section when the sum of the inflow currents to each of the divided sections is not zero, and a judgment that an accident exists in a plurality of sections as a result of the first judging means. When the determination is made, a second determination means is provided for determining that an accident exists in the section where the sum of the inflow currents of these sections is the largest.

In addition, the fault point identification system according to claim 3 introduces a detection current of each current transformer via transmission means from a plurality of current transformers installed so as to divide the power system to be protected into a plurality of sections. A combination of the means and the current transformer for partitioning the power system to be protected into a protected section having a wide area and a plurality of protected sections that subdivide the protected section having the wide area. Setting means for setting, and using the respective detection currents of the current transformers set by the setting means, when the sum of the inflow currents into the sections divided into the protected target section having the wide area is not zero, the wide area A first determining means for determining that an accident exists in the protected target section having, and when the first determining means determines that an accident exists in the protected target section having a wide area, Protected with area Determine whether the sum of the inflow currents into the multiple protected sections that subdivide the elephant section is not zero, and if there is a subdivided protected section where the sum of the inflow currents is not zero, there is an accident in this subdivided protected section And a second determination unit for determining whether to perform the determination.

(Operation) When an accident occurs, the detected current from each current transformer is introduced to the accident point identification device via transmission means. Here, the individual current system sections are pre-configured by combining the current transformers of each section with the power system, and it is determined whether or not an accident point exists for each section according to Kirchhoff's law. The accident point is identified by sequentially finding sections where is not zero.

(Example) Hereinafter, an example is described with reference to drawings.

FIG. 2 is a power system diagram of an embodiment to be examined, and the detection configuration is as shown in FIG.

In FIG. 2, current transformers 21a to 21n are provided at various places in the power system, and a plurality of sections 22a to 22f corresponding to these are configured.

The sum of the inflow currents is calculated by the CT secondary output for each system section, and it is determined whether or not an accident point exists in the section according to Kirchhoff's law. Now, if an accident occurs in the F ₁ point in the system CT21g, 21j, from the inflow current sum of the system partition 22e is not zero by 21m, it is determined that the fault point F ₁ is present in this segment within.

Also, if an accident occurs in _two points F, CT21b, 21e, from the inflow current sum of the system partition 22b and partitioning 22e is not zero according to 21h, the fault point is present in the overlapping point F ₂ of both segment Is determined.

FIG. 3 shows the concept of limiting the accident location by setting a plurality of division ranges. That is, system classification 31
If the sum of the inflow currents of each of a, 31b, and 31c is not zero, it means that a common portion (shaded portion) of each section is determined as an accident point.

FIG. 4 is a flowchart showing the contents of processing for determining an accident point according to the present invention.

First, in step S41, the output of each CT is sampled and measured at the same time and stored. Next, in step S42, the sum of the inflow currents of the CT measurement values that specify the section is calculated for each system section. Then, if the calculation result is zero in step S43, the process returns to step S41 and repeats the above processing.
That is, it is determined that there is an accident in a non-zero section.

When there are a plurality of non-zero sections in step S45, it is determined and determined that an accident has occurred at a predetermined overlapping portion of each of the sections.

Fig. 5 shows the identification of an accident point by the method of Fig. 2 and Fig. 4, when it is determined that an accident exists in that section, a smaller section is set in that section, and the CT secondary output of those sections is set. In this embodiment, the existence category of the accident is identified by the sum of the inflows. By repeating these determinations, the existence range of the accident point is limited and determined.

If the fifth diagram of F ₃ points accident, that accident is present first in-section 52a CT51a, 51f, 51i, flowing current sum 51n determines from that non-zero. Next, classification 52b by CT51a, 51f, 51h
And the CTs 51g, 51i, and 51n calculate the sum of the inflow currents of the section 52c, and determine that there is an accident on the section 52c side. Furthermore, classification 52d subdividing the segment 52c, 52e, 52f, take the algebraic sum of the CT output at each division of 52 g, determines subsection 52e presence of the fault point F ₃ to more that it is not zero.

FIG. 6 is a flowchart showing the contents of processing for determining an accident point in the embodiment shown in FIG.

In FIG. 6, steps S41 to S44 are the same as those in FIG. Then, for a section in which the sum of the inflow currents is not zero, a section for subdividing the section is set in step S61, and the sum of the inflow currents of the CT measurement values specifying this section is calculated. If a section where the sum of the inflow currents is zero is detected in step S62, the process proceeds to the next subdivision in step S63, and the above processing is repeated until a section where the sum of the inflow currents is not zero is detected. Then, when a section where the inflow sum is not zero is detected in step S62, the process proceeds to step S64, where the section is further subdivided and the same determination is performed. As a result, step S6
When a section where the sum of the inflow currents is zero is detected in step 5, the above-described processing is repeated until a section where the sum of the inflow currents is not zero is detected in step S66. Judge that there is an accident in the detection category.

FIG. 7 is a flowchart of another embodiment showing the processing contents.

Steps S41 to S45 in FIG. 7 are the same as those in FIG. In the present embodiment, when there are a plurality of sections in which the sum of the inflow currents due to the secondary outputs of the system section CT does not become zero (step S45), their sizes are compared, and in step S71, the section having the largest absolute value is determined. Is determined to be an accident point.

That is, each section is specified in the same flow as in FIG.
Calculate the inflow current sum of the CT measurement values. At this time, if there is one section in which the sum of the inflow currents is not zero, that section is an accident point. When there are a plurality of non-zero sections, those values are compared and the section having the largest value is determined as an accident point.

In this method, even if the secondary output algebra sum of the system section CT does not become zero due to, for example, the charging current of the system or other effects, the section including the fault point will have the CT algebra sum of the secondary output equivalent to the fault point current. Therefore, the algebraic sum due to the above-described phenomenon or the like is definitely larger than the sum, and the classification including the accident point can be reliably determined.

[Effects of the Invention] As described above, according to the present invention, it is possible to reliably and easily determine the point at which a system fault has occurred by calculating the algebraic sum of each CT secondary output constituting a plurality of system divisions. Can be.

Therefore, since the accident point can be identified and the situation of the accident location can be quickly grasped, the system restoration operation can be quickly and reliably performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for implementing the present invention, FIG. 2 is an example diagram of an applied system for implementing the present invention, FIG. 3 is a conceptual diagram of limiting an accident point by plural system divisions, and FIG. FIG. 5 is a flowchart showing the details of the processing for determining an accident point in FIG. 2, FIG. 5 is a system example diagram for explaining other processing contents, FIG. 6 is a flowchart showing the processing contents for determining an accident point in FIG. Seventh
FIG. 11 is a flowchart for explaining another embodiment of the processing contents. 11,21,51 ... Current transformer (CT) 12 ... line segment F ₁ by the transmission means 13 ... the fault point identifying device _{22,52 ... CT, F 2, F} 3 ... system fault point

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tetsuro Matsushima 1 Toshiba-cho, Fuchu-shi, Tokyo Inside Naka-plant, Toshiba-fu Co., Ltd. (56) Reference Reference

Claims (3)

(57) [Claims] 1. Introducing means for introducing detection current of each current transformer via a transmission means from a plurality of current transformers installed so as to divide a power system to be protected into a plurality of sections; Setting means for setting a combination of the current transformers so as to divide the system into a plurality of protection target sections; and each of the sections divided using the respective detection currents of the current transformers set by the setting means. A first judging means for judging that an accident exists in the section when the sum of the inflow currents to the sections is not zero, and, when the first judging means judges that an accident exists in a plurality of sections, An accident point identification system, comprising: a second judging means for judging that an accident exists in the overlap area when there is an overlap area between the two. 2. Introducing means for introducing detection current of each current transformer via transmission means from a plurality of current transformers installed so as to divide a power system to be protected into a plurality of sections, and said power to be protected. Setting means for setting a combination of the current transformers so as to divide the system into a plurality of protection target sections; and each of the sections divided using the respective detection currents of the current transformers set by the setting means. A first judging means for judging that an accident exists in the section when the sum of the inflow currents to the sections is not zero, and, when the first judging means judges that an accident exists in a plurality of sections, And a second judging means for judging that an accident exists in the section where the sum of the inflow currents is the largest. 3. Introducing means for introducing detection current of each current transformer via a transmission means from a plurality of current transformers installed so as to divide a power system to be protected into a plurality of sections, and said power to be protected. Setting means for setting a combination of the current transformer for partitioning the system into a protected target section having a wide area and a plurality of protected target sections for subdividing the protected target section having the wide area; and the setting means. When the sum of the inflow currents to the sections divided into the protected section having the wide area is not zero by using the respective detection currents of the current transformer set in First determining means for determining that an accident exists; and, when the result of the first determining means determines that an accident exists in a protected area having a wide area, the protected area having the wide area is determined. Multiple subdivisions A second determining means for determining whether or not the sum of the inflow currents to the protection target section is not zero, and when there is a subdivided protection target section in which the inflow current sum is not zero, determining that an accident exists in the subdivision protection target section; An accident point identification system comprising: