Wiring method for circular distribution line, and circular distribution line

Abstract

To suppress a cyclic current generated in an annular power distribution wire.SOLUTION: The present invention relates to a wiring method for an annular power distribution wire consisting of wires of a plurality of different phases and configured by aligning the wires. An alignment order of the wires of the plurality of phases in a first line portion of the annular power distribution wire is reversed with respect to an alignment order of the wires of the plurality of phases in a second line portion at a side opposed with the first line portion.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a wiring method for a ring-shaped power distribution line and the ring-shaped power distribution line. [Background technology]

[0002] Various types of busbar configurations (e.g., three-phase, three-wire distribution lines) installed in substations have been proposed. Among these, the ring busbar is known as a highly reliable busbar configuration that excels in responding to risks such as ground faults.

[0003] In a substation's ring bus, current flowing in from the transformer flows through the ring bus and is transmitted to the transmission line. However, the path of the current flowing through this ring bus can change depending on the circuit configuration of the ring bus, the configuration of the transformer or transmission line, or changes in current or voltage. As a result, some of the current flowing through the ring bus can circulate through the ring bus without flowing from the transformer to the transmission line (circulating current, or zero-phase circulating current). When circulating current occurs, it can cause protective relays in the circulating bus to malfunction, resulting in the tripping of a circuit breaker. Therefore, it is important in substation operation to prevent circulating current as much as possible.

[0004] Circulating current is a phenomenon that can occur in a circuit in which current circulates. Regarding a method for suppressing circulating current in a switch, for example, Patent Document 1 describes a cross current compensation control system for a power system that includes a cross current detection compensator, the cross current detection compensator having an input terminal connected to a cross-connection line that cross-connects the secondary sides of auxiliary current transformers, and an output terminal connected to a cross current compensation line that connects the secondary sides of multiple current transformers in series, and that, when it detects a cross current circulating through a bus, a distribution line, and the switch, supplies a compensation current to the cross current compensation line so as to cancel out the current component corresponding to the cross current that appears on the secondary side of the current transformer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-189476 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is currently no effective means for dealing with the circulating current that occurs in the circulating bus of a substation.

[0007] The present invention has been made in consideration of the above-described situation, and its object is to provide a wiring method for a circular distribution line that can suppress circulating currents occurring in the circular distribution line, and the circular distribution line. [Means for solving the problem]

[0008] One aspect of the present invention for achieving the above-mentioned object is a wiring method for a circular distribution line that is composed of electric wires of different phases and that is arranged in a row, wherein the order in which the electric wires of the different phases are arranged in a first line portion of the circular distribution line is reversed from the order in which the electric wires of the different phases are arranged in a second line portion opposite to the first line portion.

[0009] The inventors have discovered that the circulating current occurring in the circulating bus can be suppressed by reversing the arrangement order of the electric wires of each phase in the line portion of the circulating bus from the arrangement order of the electric wires of each phase in the line portion opposite to the line portion of the circulating bus. In this way, the wiring method for the ring-shaped distribution line of the present invention can suppress the circulating current occurring in the ring-shaped distribution line.

[0010] Furthermore, one aspect of the present invention for achieving the above-mentioned object is a wiring method for a circular distribution line, characterized in that the order of arrangement of the electric wires of the multiple phases in a line portion of the distribution line on the side where current flows into the circular distribution line is reversed from the order of arrangement of the electric wires of the multiple phases in a line portion of the distribution line on the side where current that has flowed through the circular distribution line flows out.

[0011] In this way, by reversing the order in which the electric wires of each phase are arranged in the line section on the side where the current flows into the ring distribution line and the order in which the electric wires of each phase are arranged in the line section on the side where the current that has flowed through the ring distribution line flows out, the circulating current generated in the circulating bus can be more reliably suppressed.

[0012] Furthermore, one aspect of the present invention for achieving the above-mentioned object is a circular distribution line made up of electric wires of a plurality of different phases, each of the electric wires being aligned, wherein the order in which the electric wires of the plurality of phases are aligned in a first line portion of the circular distribution line is reverse to the order in which the electric wires of the plurality of phases are aligned in a second line portion opposite to the first line portion.

[0013] Furthermore, one aspect of the present invention for achieving the above-mentioned object is a circular distribution line, characterized in that the arrangement order of the electric wires of the multiple phases in a line portion of the distribution line on the side where current flows into the circular distribution line is reversed from the arrangement order of the electric wires of the multiple phases in a line portion of the distribution line on the side where current that has flowed through the circular distribution line flows out. [Effects of the Invention]

[0014] According to the present invention, it is possible to suppress the circulating current occurring in the ring distribution line. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a diagram illustrating an example of the configuration of a circulation bus, which is a ring-shaped distribution line in the present embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a wiring configuration of a circulation bus according to the present embodiment. [Figure 3] 3 is a diagram of the circulating bus shown in FIG. 2 as seen from the side (the first line portion side). FIG. [Figure 4] FIG. 1 is a circuit diagram of a circulating bus set for an XTAP in this embodiment. [Figure 5] FIG. 10 is a diagram showing the effective values ​​and phase values ​​of the current in each switch in the conventional case and the invention case. [Figure 6]FIG. 10 is a diagram showing values ​​of circulating current (zero-phase current) generated in a switch in each of the conventional case and the invention case. [Figure 7] FIG. 10 is a diagram showing values ​​of circulating current (zero-phase current) generated in a switch in each of the conventional case and the invention case. [Figure 8] FIG. 1 is a diagram showing an example of a wiring configuration of a conventional circulation bus. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a wiring method for a ring-shaped distribution line and the ring-shaped distribution line according to one embodiment of the present invention will be described with reference to the drawings.

[0017] Fig. 1 is a diagram showing an example of the configuration of a circulation bus, which is a ring-shaped distribution line in this embodiment. This circulation bus 10 is a ring-shaped distribution line and is installed in, for example, a substation. Electric lines 21 (high voltage side) from multiple transformers 20 and multiple transmission lines 30 (low voltage side) are connected to the circulation bus 10. The transmission lines 30 are connected to consumers (not shown) and the like.

[0018] The circulation bus 10 is composed of a bus bar A 11 on the transformer 20 side, a bus bar B 12 on the transmission line 30 side, a first line section 13 connecting one end of the bus bar A 11 to one end of the bus bar B 12, and a second line section 14 connecting the other end of the bus bar A 11 to the other end of the bus bar B 12. In the following, the side of the circulation bus bar 10 that faces the first line section 13 will be referred to as the first side, and the side of the second line section 14 will be referred to as the second side.

[0019] In this embodiment, the A bus bar 11 and the B bus bar 12 each constitute a track in the long axis direction of the circulating bus bar 10 and are arranged in positions opposite to each other. Also, the first track portion 13 and the second track portion 14 each constitute a track in the short axis direction of the circulating bus bar 10 and are arranged in positions opposite to each other.

[0020] The electric wires 21 from each transformer 20 on the high-voltage side are connected to a bridging electric wire 15 that bridges between a predetermined position on the A bus bar 11 and a predetermined position on the B bus bar 12. A disconnector 16 is provided at a predetermined position on the bridging electric wire 15 on the A bus bar 11 side from the connection part of the bridging electric wire 15, and at a predetermined position on the bridging electric wire 15 on the B bus bar 12 side from the connection part of the bridging electric wire 15.

[0021] Each low-voltage side transmission line 30 is connected to a connection on a bridging electric wire 17 that bridges between a predetermined position on the A bus 11 and a predetermined position on the B bus 12. A disconnector 18 is provided at a predetermined position on the bridging electric wire 17 on the A bus 11 side from the connection on the bridging electric wire 17, and at a predetermined position on the bridging electric wire 17 on the B bus 12 side from the connection on the bridging electric wire 17.

[0022] Furthermore, circuit breakers 19 are provided at predetermined positions on the A bus bar 11, the B bus bar 12, the first line portion 13, and the second line portion 14, respectively.

[0023] In the above configuration, electricity flows from the transformer 20 into the A busbar 11 of the circulating busbar 10, and the current flows through one of the lines of the circulating busbar 10, and then flows out from the B busbar 12 to the transmission line 30 side.

[0024] Here, for example, if a worker finds that a circulating current has occurred in the circulation bus 10, causing an abnormality, he can operate the circuit breaker 19 closest to the abnormality to cut off the current near the abnormality, and also switch the disconnectors 16, 18 on the bridging wires 15, 17, thereby securing a path for current transmission from the transformer 20 via the circulation bus 10 to the transmission line 30 without using the line near the abnormality. However, such work is very complicated, and it is desirable to prevent circulating currents as much as possible.

[0025] 2 is a diagram showing an example of the wiring configuration of the circulation bus 10 of this embodiment. This circulation bus 10 is made up of three-phase, three-wire electric wires arranged in a row and substantially parallel to one another. Specifically, the circulation bus 10 is made up of three wires: a first-phase electric wire 51 (red), a second-phase electric wire 52 (white), and a third-phase electric wire 53 (blue).

[0026] Conventionally, the arrangement direction of the first-phase electric wire 51 (red), the second-phase electric wire 52 (white), and the third-phase electric wire 53 (blue) is the same for the A bus bar 11 and the B bus bar 12. For example, as shown in Figure 8, for both the A bus bar 11 and the B bus bar 12 of the circulation bus bar 10, the first-phase electric wire 51 (red), the second-phase electric wire 52 (white), and the third-phase electric wire 53 (blue) are arranged in this order from the high-voltage side (transformer 20 side) to the low-voltage side (transmission line 30 side).

[0027] The arrangement direction of the first phase electric wire 51 (red), the second phase electric wire 52 (white), and the third phase electric wire 53 (blue) is also the same in the first line portion 13 and the second line portion 14. For example, as shown in Fig. 8, in both the first line portion 13 and the second line portion 14 of the circulation bus 10, the first phase electric wire 51 (red), the second phase electric wire 52 (white), and the third phase electric wire 53 (blue) are aligned in this order from the first side to the second side.

[0028] However, in the circulation busbar 10 of this embodiment, the arrangement directions of the first phase electric wire 51 (red), the second phase electric wire 52 (white), and the third phase electric wire 53 (blue) are reversed between the A busbar 11 and the B busbar 12.

[0029] 2, the three wires in the A busbar 11 of the circulation busbar 10 are arranged in the order of first phase electric wire 51 (red), second phase electric wire 52 (white), and third phase electric wire 53 (blue) from the high voltage side (transformer 20 side) to the low voltage side (transmission line 30 side), while the three wires in the B busbar 12 of the circulation busbar 10 are arranged in the order of third phase electric wire 53 (blue), second phase electric wire 52 (white), and first phase electric wire 51 (red) from the high voltage side (transformer 20 side) to the low voltage side (transmission line 30 side). In other words, the arrangement order of the wires is reversed between the A busbar 11 and the B busbar 12.

[0030] Although the above describes the arrangements of red-white-blue and blue-white-red, other color patterns are also possible (for example, the arrangements of blue-white-red and red-white-blue).

[0031] Furthermore, in the circulation bus 10 of this embodiment, the arrangement directions of the first phase electric wire 51 (red), the second phase electric wire 52 (white), and the third phase electric wire 53 (blue) are reversed to the first line portion 13 and the second line portion 14.

[0032] 2, the three wires in the first line portion 13 of the circulation bus 10 are arranged from the first side to the second side in the order of the first phase electric wire 51 (red), the second phase electric wire 52 (white), and the third phase electric wire 53 (blue), while the three wires in the second line portion 14 of the circulation bus 10 are arranged from the first side to the second side in the order of the third phase electric wire 53 (blue), the second phase electric wire 52 (white), and the first phase electric wire 51 (red). In other words, the arrangement order of the electric wires is reversed between the first line portion 13 and the second line portion 14.

[0033] Although the above describes the arrangements of red-white-blue and blue-white-red, other color patterns are also possible (for example, the arrangements of blue-white-red and red-white-blue).

[0034] 3 is a side view (the side of the first line portion 13) of the circulation bus 10 shown in FIG. 2. The circulation bus 10 is supported by a support member 32 erected on the site 3 of the substation, and is fixed at a predetermined height from the circulation bus 10. The plane of the circulation bus 10 is set to be approximately parallel to the surface of the site 3.

[0035] Specifically, the A busbar 11 of the circulation busbar 10 is arranged in the order of a first-phase electric wire 51 (red), a second-phase electric wire 52 (white), and a third-phase electric wire 53 (blue), from the high-voltage side (the transformer 20 side) to the low-voltage side (the transmission line 30 side), substantially parallel to the surface of the site 31. The B busbar 12 of the circulation busbar 10 is arranged in the order of a third-phase electric wire 53 (blue), a second-phase electric wire 52 (white), and a first-phase electric wire 51 (red), from the high-voltage side (the transformer 20 side) to the low-voltage side (the transmission line 30 side), substantially parallel to the surface of the site 31.

[0036] In this way, by reversing the arrangement order of the electric wires of each phase in the first track portion (A busbar 11, first track portion 13) of the circulation busbar 10 and the arrangement order of the electric wires of each phase in the second track portion (B busbar 12, second track portion 14) on the opposite side to the above track portion, it is possible to suppress the circulating current occurring in the circulation busbar. This reduces the frequency with which workers have to perform cumbersome response work such as operating the circuit breaker 19 and disconnecting switches 16 and 18 due to the occurrence of circulating current.

[0037] <Example> Next, the inventors have clarified that the circulating current can be suppressed by using a circulating bus bar employing the above-described wiring configuration, by constructing and executing the following simulation model.

[0038] The simulation model used by the inventors is XTAP (registered trademark) (Central Research Institute of the Electric Power Industry), an instantaneous value analysis program. The wire layout was input to XTLC, an impedance calculation program installed in XTAP, to determine the impedance of each element in the circuit, and the determined impedance was then input into XTAP to determine the circulating current occurring in the circulating bus.

[0039] 4 is a circuit diagram of the circulating bus set for the XTAP in this embodiment. This circulating bus 300 consists of a bus A 310 to which electric wires from a first current source 301 and a second current source 302 (each assumed to be a transformer) are connected and to which electric wires to a third current source 303 and a fourth current source 304 (assumed to be a transmission line to a consumer) are connected, a bus B 315 to which an electric wire to a fifth current source 305 (assumed to be a transmission line to a consumer) is connected, a first cross-linking wire 320 connecting one side of the bus A 310 to one side of the bus B 315, and a second cross-linking wire 325 connecting the other side of the bus A 310 to the other side of the bus B 315. Furthermore, a connection line 326 that connects a predetermined position on the A bus 310 with a predetermined position on the B bus 315 is connected to a wire (assuming a transmission line to a consumer) to the sixth current source 306. These current sources simulate the current flowing into or out of the circulating bus 300.

[0040] In addition, a switch 360 is provided on the A busbar 310, a switch 370 is provided on the B busbar 315, a switch 350 is provided on the first bridging wire 320, and a switch 340 is provided on the second bridging wire 325.

[0041] Furthermore, a switch 332 is provided on an electric wire 361 from the first current source 301. A switch 331 is provided on an electric wire 362 from the second current source 302. A switch 344 is provided on an electric wire 363 to the third current source 303. A switch 342 is provided on an electric wire 364 to the fourth current source 304. A switch 343 is provided on an electric wire 365 to the fifth current source 305. A switch 341 is provided on an electric wire 366 to the sixth current source 306.

[0042] Based on the above circuit configuration, we set up a case where the circulating bus 300, which is a three-phase three-wire distribution line, is wired in a conventional manner (hereinafter referred to as the conventional case) and a case where the wiring according to this embodiment is adopted (hereinafter referred to as the invention case). Then, for each of the conventional case and the invention case, we simulated how current flows through the circulating bus 300 by passing it from each current source.

[0043] Specifically, in the conventional case, first, the first-phase electric wire (red), the second-phase electric wire (white), and the third-phase electric wire (blue) in each of the A bus bar 310 and the B bus bar 315 of the circulation bus bar 300 were set to be aligned in this order from the side of the first current source 301, etc. (assuming the substation side) toward the side of the fifth current source 305, etc. (assuming the transmission line side). Also, the first-phase electric wire (red), the second-phase electric wire (white), and the third-phase electric wire (blue) in each of the first cross-linking wire 320 and the second cross-linking wire 325 of the circulation bus bar 300 were set to be aligned in this order from the side of the first cross-linking wire 320 (assuming the first side) toward the side of the second cross-linking wire 325 (assuming the second side).

[0044] In the invention case, the first-phase electric wire (red), the second-phase electric wire (white), and the third-phase electric wire (blue) in the A bus 310 of the circulating bus 300 were set to be aligned in this order from the side of the first current source 301, etc. (assuming the substation side) toward the side of the fifth current source 305, etc. (assuming the transmission line side). On the other hand, in the B bus 315 of the circulating bus 300, the third-phase electric wire (blue), the second-phase electric wire (white), and the first-phase electric wire (red) were set to be aligned in this order from the side of the first current source 301, etc. (assuming the substation side) toward the side of the fifth current source 305, etc. (assuming the transmission line side).

[0045] In the invention case, the first-phase electric wire (red), the second-phase electric wire (white), and the third-phase electric wire (blue) in the first cross-linking wire 320 of the circulation bus 300 were arranged in this order from the first cross-linking wire 320 side (assumed to be the first side) toward the second cross-linking wire 325 side (assumed to be the second side). On the other hand, in the second cross-linking wire 325 of the circulation bus 300, the third-phase electric wire (blue), the second-phase electric wire (white), and the first-phase electric wire (red) were arranged in this order from the first cross-linking wire 320 side (assumed to be the first side) toward the second cross-linking wire 325 side (assumed to be the second side).

[0046] Figure 5 shows the effective value and phase of the current at each switch in the conventional case and the inventive case. In the figure, "lm" indicates the effective value of the current (unit: A), and "Ph" indicates the phase (unit: deg). The numbers on the switches correspond to the reference symbols in the drawings attached to the switches described above. Furthermore, "a," "b," and "c" respectively indicate the first, second, and third phases of the circulating bus 300. These settings were used to simulate the current flowing into or out of the circulating bus 300.

[0047] Furthermore, Figure 6 shows the values ​​of the circulating current (zero-phase current) generated in the switch 360 in the conventional case and the invention case. As shown in the figure, a circulating current of 226.39 mA was generated in the conventional case, but in the invention case, the circulating current was reduced to 102.59 mA, less than half of that.

[0048] In this way, it was found that the circulating current can be significantly reduced by reversing the arrangement of the three wires (three phases) in the A busbar and the B busbar, and further by reversing the arrangement of the three wires (three phases) in one bridge wire and the other bridge wire.

[0049] As described above, the circular distribution line and the wiring method of the circular distribution line of this embodiment can suppress the circulating current generated in the circulating bus by reversing the order in which the electric wires of each phase are arranged in the line portion (A bus 11, first line portion 13) of the circulating bus 10 and the order in which the electric wires of each phase are arranged in the line portion opposite to the above line portion (B bus 12, second line portion 14).

[0050] In particular, the circular distribution line and the wiring method for the circular distribution line of this embodiment can more reliably suppress the circulating current occurring in the circulation bus by reversing the order in which the electric wires of each phase are arranged in the A bus 11, which is the side where current flows into the circulation bus 10, and the order in which the electric wires of each phase are arranged in the B bus 12, which is the line portion where the current that has flowed through the circulation bus 10 flows out.

[0051] The above description of the embodiments is intended to facilitate understanding of the present invention, and is not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention includes equivalents thereof.

[0052] For example, in this embodiment, the case of a circular bus in a substation has been described, but the present invention can also be applied to a circular distribution line in a facility other than a substation.

[0053] In addition, in this embodiment, the circulation bus is three-phase, three-wire, but the present invention can also be applied to other types of distribution lines (for example, three-phase, four-wire type) that are made up of electric wires of different phases and each electric wire is aligned. [Explanation of symbols]

[0054] 10 Circulation busbar 11 A bus line 12 Bus Line 13 First track section 14 Second track section 20 Transformer 30 Power Lines

Claims

1. A wiring method for a circular distribution line that is made up of electric wires of different phases and in which the electric wires are aligned, comprising: an arrangement order of the electric wires of the multiple phases in a first line portion of the annular distribution line, on a side where a current flows into the annular distribution line, is reversed from an arrangement order of the electric wires of the multiple phases in a second line portion opposite to the first line portion, on a side where a current that has flowed through the annular distribution line flows out; A wiring method for a ring distribution line, comprising:

2. A circular distribution line is made up of electric wires of different phases, each of which is aligned, an arrangement order of the electric wires of the multiple phases in a first line portion of the annular distribution line, on a side where a current flows into the annular distribution line, is reversed from an arrangement order of the electric wires of the multiple phases in a second line portion opposite to the first line portion, on a side where a current that has flowed through the annular distribution line flows out; A circular distribution line characterized by:

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