JP2007116774A - Power distribution system and on-street reactor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power distribution system which can compensate a one-line grounding current surely and inexpensively even in the case that distribution lines of large capacitance to the earth are mixed and even if the switching of distribution systems is performed, and an on-street reactor device. <P>SOLUTION: On-street reactor devices RC1-RC9 which have reactors for compensating grounding currents for distribution lines C1-C9 of cables arranged underground and are arranged on the ground, are distributed to correspond to the magnitude of the capacitance to the earth of the distribution lines C1-C9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power distribution system and a road reactor device capable of reliably and inexpensively compensating for a one-wire ground fault current.

  Conventionally, many high-voltage distribution lines have been ungrounded, but when a ground fault occurs in a high-voltage distribution system, a ground fault current and a zero-phase voltage are generated. As for this ground fault current, a portion corresponding to the ground charging current of the line flows. Further, in recent years, the capacitance to the ground has increased as the wiring lines have become underground or cabled, and as a result, the ground fault current tends to increase.

  Here, when installing a pole transformer on a distribution line, it is necessary to provide Class B grounding according to electrical equipment technical standards in order to cope with the occurrence of a ground fault. The resistance value of this type B ground is determined by the magnitude of the one-line ground fault current of the distribution line. When the one-line ground fault current is large, it is necessary to provide the type B ground with a low resistance value. However, this type B grounding having a low resistance value requires a large cost because the construction takes time and labor.

On the other hand, a reactor for compensating the one-wire ground fault current can be provided as a measure for suppressing the one-wire ground fault current. The method of lowering the resistance value of the class B ground described above is a method of reducing the voltage generated on the low voltage side when the high / low pressure contact represented by the following formula (1) is suppressed by suppressing the class B ground resistance value. , This reactor is intended to reduce the voltage generated on the low voltage side when the high / low pressure is mixed by suppressing the magnitude of the ground fault current itself.
Voltage generated on the low voltage side when high / low pressure is mixed = 1-wire ground fault current x Class B ground resistance value (1)

JP 2005-77316 A

  However, when a conventional power distribution system has a non-electric poled area provided with distribution lines realized by underground cables, the above-described aerial reactor cannot be installed in the non-electric poled area. Although the one-line ground fault current was compensated by the above-described B-type grounding, the ground capacitance in this non-electric pole area is, for example, about 150 times larger and lower than the ground electrostatic amount of the overhead wire. Construction of resistance type B grounding has to be performed, and there has been a problem that it is very costly to compensate for one-wire ground fault current.

  On the other hand, if the low resistance type B grounding work is not performed in this non-electric pole area, the above-described aerial reactors are intensively arranged in the nearby power pole area outside the non-electric pole area, and the one-wire ground fault current I had compensation.

  For example, as shown in FIG. 5, in the conventional distribution system, the two substations 100 and 200 are branched into four distribution systems A1 to A4 and B1 to B4, respectively, and are distributed to the respective distribution systems A1 to A4 and B1 to B4. As appropriate, the distribution line is connected and disconnected by a switch. Here, the distribution systems A1 and B1 are connected and disconnected by the switch S14. Normally, the switch S14 is disconnected according to the energy supply capacity of the substations 100 and 200, and the distribution system A1 and the distribution system are connected. B1 is formed. The distribution system A1 is provided with the distribution lines C1 and C2 of the cables provided in the ground and the distribution line W1 aerially arranged by the utility poles from the transformer 10 side, and the distribution system B1 includes the transformer. Distribution lines W4, W3, and W2 that are aerially arranged by power poles are provided sequentially from the 20 side, two aerial reactors RW1 and RW2 are provided on the distribution line W1, and one aerial reactor RW4 is provided on the distribution line W4. Is provided. The number of overhead reactors provided in the power distribution system A1 is larger than that in the power distribution system B1. The power distribution line A1 has power distribution lines C1 and C2, and the ground capacitance is large. Since the reactor cannot be arranged on the distribution line C1, C2, the distribution system A2, A3, and the distribution line C7 of the distribution system A4, the distribution line W1 of the distribution system A1 where the reactor can be installed and the distribution line W9 of the distribution system A4, The reason is that reactors necessary for the distribution systems A1 to A4 are concentrated. Similarly, aerial reactors are concentratedly arranged on the distribution lines W7 and W8 of the distribution systems B3 and B4.

  In this case, when switching of the distribution system occurs in the distribution systems A1 and B1, for example, as shown in FIG. 6, when the switch S13 is disconnected and the switch S14 is connected, the distribution systems A1 and B1 are connected to the distribution line. The distribution system is changed to a distribution system A1 "composed of C1 and C2 and a distribution system B1" composed of distribution lines W1 to W4. Here, since the distribution system A1 ″ has no reactor disposed on the distribution lines C1 and C2, the one-line ground fault current cannot be compensated, and the distribution system B1 ″ has the ground capacitance of the distribution lines W1 to W4. There are three aerial reactors larger than the above, and an overcompensation state occurs. In this case, if a ground fault occurs in the distribution system A1 ″, the one-line ground fault current cannot be compensated, and if a ground fault occurs in the distribution system B1 ″, the ground fault relay does not operate. There was a problem that the location where the ground fault occurred was also mistaken.

  The present invention has been made in view of the above, and is reliable and inexpensive even when wiring lines having a large ground capacitance are mixed or when switching of the distribution system occurs. An object of the present invention is to provide a power distribution system and a road reactor device capable of performing one-line ground fault current compensation.

  In order to solve the above-described problems and achieve the object, a power distribution system according to claim 1 includes a reactor that compensates for a ground fault current from the power distribution line, and the road reactor device disposed on the ground is connected to the power distribution line. It is characterized by being distributed according to the size of the ground capacitance.

  The power distribution system according to claim 2 is characterized in that, in the above invention, the road reactor device is provided for a power distribution line formed by a cable disposed in the ground.

  The power distribution system according to claim 3 is characterized in that, in the above invention, the road reactor device changes the size of the reactor according to the size of the ground capacitance of the distribution line.

  According to a fourth aspect of the present invention, there is provided a power distribution system according to the above invention, wherein the road reactor device includes substantially equal reactors, and is arranged in a sparse and dense manner according to a ground capacitance of the distribution line.

  According to a fifth aspect of the present invention, in the power distribution system according to the present invention, the road reactor device includes an opening / closing device that cuts off a load current between the power distribution line and the reactor.

  According to a sixth aspect of the present invention, there is provided the power distribution system according to the above invention, further comprising a protective device that is connected between the switchgear and the reactor and blocks a short-circuit current.

  According to a seventh aspect of the present invention, there is provided a power distribution system according to the above invention, wherein the protective device is a three-pole type in which a discharge fuse is detachably mounted on the distribution line side of a reactor branched and connected to each phase of the distribution line. A switching device with a protective function in which a series circuit of a primary cutout with an interlocking opening function and a primary cutout in which a current limiting fuse having a breaking function is detachably mounted is provided.

  The power distribution system according to claim 8 is characterized in that, in the above invention, the rated current of the discharge fuse is set smaller than the rated current of the current limiting fuse.

  A road reactor device according to claim 9 has a size corresponding to a ground capacitance of a distribution line to be connected, a reactor that suppresses a flow of a ground fault current, and an outer frame that covers and protects the reactor. And is arranged on the ground near the distribution line.

  A road reactor device according to a tenth aspect of the present invention includes, in the above invention, an opening / closing device that is provided between the distribution line and the reactor and that cuts off a load current from the distribution line. It is provided in the outer frame.

  An on-road reactor device according to an eleventh aspect of the present invention includes a protection device that is connected between the switchgear and the reactor and that cuts off a short-circuit current, and the protection device is disposed in the outer frame. It is provided.

  The road reactor device according to a twelfth aspect of the present invention is the roadside reactor device according to the above invention, wherein the protection device includes three discharge fuses that are detachably mounted on the distribution line side of the reactor branched and connected to each phase of the distribution line. A switching device with a protective function is provided, in which a series circuit of a primary cutout with a pole interlocking open function and a primary cutout in which a current limiting fuse having a cutoff function is detachably mounted is arranged.

  According to a thirteenth aspect of the present invention, in the above-described invention, the rated current of the discharge-type fuse is set smaller than the rated current of the current-limiting fuse.

  A power distribution system and a road reactor device according to the present invention include a reactor that compensates for a ground fault current from a distribution line, and the road reactor device disposed on the ground corresponds to the size of the ground capacitance of the distribution line. Even if there are mixed wiring lines with large capacitance to ground, such as underground and cabled distribution lines, or when the distribution system is switched Even if it exists, there exists an effect that 1 line ground fault current compensation can be performed reliably and cheaply.

  A power distribution system and a road reactor device that are the best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram showing a schematic configuration of a power distribution system including a road reactor device according to an embodiment of the present invention. In FIG. 1, the power distribution system 1 includes substations 100 and 200 and distribution systems A1 to A4 and B1 to B4 that are divided from the transformers 10 and 20 of the substations 100 and 200, respectively. Here, the distribution systems A1 and B1 can be connected by a switch S14.

  The substations 100 and 200 have transformers 10 and 20, respectively. The transformers 10 and 20 are connected to, for example, a 60,000-volt distribution line (not shown), and each of the transformers 100 and 20 includes four distribution cables C10 and C20. Power distribution to 6600 volt distribution systems A1 to A4 and B1 to B4. The wiring system A1 is connected to the distribution cable C10 via the switch S11. From the switch S11, the distribution lines C1 and C2 realized by the cables disposed in the ground and the overhead distribution line W1 are connected. Are sequentially connected through switches S12 and S13. The wiring system A2 is connected to the distribution cable C10 via the switch S21, and the distribution lines C3 and C4 realized by the cables disposed in the ground are sequentially transferred from the switch S21 via the switch S22. It is connected. The wiring system A3 is connected to a distribution cable C10 via a switch S31, and distribution lines C5 and C6 realized by cables arranged in the ground are sequentially connected via a switch S32. The wiring system A4 is connected to the distribution cable C10 via the switch S41, and the distribution line C7 realized by the cable disposed in the ground and the overhead distribution line W9 are connected via the switch S42. Connected sequentially.

  Further, the wiring system B1 is connected to the distribution cable C20 via the switch S17, and the overhead distribution lines W4, W3, W2 are sequentially connected via the switches S16, S15. Here, as described above, the distribution lines W1 and W2 can be connected via the switch S14. In FIG. 1, the distribution lines W1 and W2 are cut off. The wiring system B2 is connected to the distribution cable C20 via the switch S27, and the overhead distribution lines W6 and W5 are sequentially connected via the switch S26. The wiring system B3 is connected to the distribution cable C20 via the switch S37, and the distribution line C8 realized by the cable arranged in the ground and the overhead distribution line W7 are connected via the switch S36. Connected sequentially. The distribution system B4 is connected to the distribution cable C20 via the switch S47, and the distribution line C9 realized by the cable arranged in the ground and the overhead distribution line W8 are connected via the switch S46. Connected sequentially.

  The distribution lines C1 to C9 are cables disposed in the ground as described above, and the distribution lines W1 to W9 are disposed overhead as described above. Since the distribution lines C1 to C9 have a very large capacitance to ground compared to the distribution lines W1 to W9, and the low resistance type B grounding work requires a large cost, as shown in FIG. Road reactor devices RC1 to RC9 having reactors arranged on the ground are installed in C1 to C9, respectively, and one-line ground fault current compensation is performed by the road reactor devices RC1 to RC9. On the other hand, the distribution lines W4 and W6 among the distribution lines W1 to W9 are respectively provided with overhead reactor devices RW4 and RW6 arranged on the power pole. The overhead reactor device RW4 performs one-line ground fault compensation for the distribution lines W2, W3, and W4. Further, the overhead reactor device RW6 performs one-line ground fault compensation for the distribution lines W5 and W6. The road reactor devices RC7 to RC9 also perform one-line ground fault compensation for the distribution lines W7, W8, and W9, respectively.

  Road reactor devices RC1 to RC9 are installed on the ground, unlike aerial reactor devices RW1 to RW9. In general, a large-capacity reactance is heavy, and in order to place a large-weight reactance on a utility pole, it is fixed depending on the load resistance at the installation position of the utility pole, size restrictions, measures against wind and rain, traffic height restrictions, etc. Capacity restrictions are added. On the other hand, the road reactor apparatuses RC1 to RC9 can install reactances of almost unlimited size in a relatively free position in a free shape. Further, since the road reactor devices RC1 to RC9 do not need to be reduced in size and weight to facilitate the construction involved in the installation, a reactor having a large reactance can be easily and inexpensively installed. .

  Moreover, since the reactor devices RC1 to RC9 on the road can easily change the setting of the reactance, it is possible to install a reactor according to the size of the ground capacitance of the distribution lines C1 to C9. In this case, each of the road reactor devices RC1 to RC9 can be installed at almost equal intervals. On the contrary, when the capacity | capacitance of the reactor of each road reactor apparatus RC1-RC9 is substantially the same, each road reactor apparatus RC1-RC9 is densely arrange | positioned in the place where ground capacitance is large, and the place where ground capacitance is small In sparsely arranged.

  Furthermore, since the road reactor devices RC1 to RC9 can install large reactors, the number of installations for the distribution lines C1 to C9 having a large ground capacitance can be reduced, thereby reducing the cost for installing the reactors. Can be planned.

  In particular, since the distribution lines C1 to C9 have a ground capacitance of about 150 times larger, for example, if the same reactor as the overhead reactor units RW1 to RW9 is installed in the distribution lines C1 to C9, it is 150 times even if simply considered. Although it is necessary to provide a reactor, the number of installations can be extremely reduced by the road reactor devices RC1 to RC9, and the construction cost can be significantly reduced.

  Moreover, in this power distribution system 1, the road reactor apparatus RC1-RC9 which has the reactance corresponding to the earth | ground capacitance of each distribution line C1-C9 also with respect to the distribution lines C1-C9 implement | achieved by the underground distribution cable. 2 is distributed, for example, when the switch S14 is closed, the switch S12 is opened, and the distribution systems A1 and B1 are changed to the distribution systems A1 ′ and B1 ′ as shown in FIG. Even if there is a reactor with reactance corresponding to the capacitance to ground of each distribution system A1 ′, B1 ′, 1-line ground fault current compensation is appropriately performed to prevent overcompensation can do.

  FIG. 3 is a schematic diagram showing a schematic configuration of a road reactor device RC1 provided in the distribution line C1. As shown in FIG. 3, this road reactor device RC1 includes a switching device 2 that cuts off a load current, a protection device 3 that cuts off a short-circuit current, and a reactor 12 on a base 5 fixed on the ground with cement or the like. Is provided. That is, the reactor 12 is branched and connected to the underground distribution line C1 (not shown) via the cable C30, and the switchgear 2 and the protection device 3 are connected between the distribution line C1 and the reactor 12 from the distribution line C1 side. Sequentially connected.

  The road reactor device RC1 covers the opening / closing device 2, the protection device 3, the reactor 12, and the cable C30 with the outer frame 4. The outer frame 4 is realized by, for example, a metal box, and protects the reactance 12 and the like electrically and mechanically and has environmental resistance.

  The protection device 3 is for cutting off a short-circuit current when the reactor 12 is short-circuited. When the protection device 3 is a highly reliable reactor 12 that is difficult to cause a short-circuit, there is a possibility that the reactor 12 itself may be short-circuited. Since it becomes very low, it is not necessary to provide the protective device 3.

  Further, instead of the switchgear 2 and the protection device 3, a switchgear 30 with a protective function such as a protection circuit described in Japanese Patent Application No. 2004-141538 may be provided. FIG. 4 is a diagram illustrating a schematic configuration of a road reactor device RC1 including the opening / closing device 30 with a protective function. As shown in FIG. 4, a reactor 12 is connected to each phase (U phase, V phase, W phase) of the distribution line C1 via a branch cable C30 (11u, 11v, 11w). The neutral point of the reactor 12 is grounded. A series circuit of a cutout 13 with a three-pole interlocking opening function and a cylindrical cutout 14 is provided on the distribution line C1 side of the reactor 12. The cutout 13 with the three-pole interlocking opening function is internally provided with a discharge fuse 13a, and the cylindrical cutout 14 is provided with a current limiting fuse 14a.

  As shown in FIG. 4, the cylindrical cutout 14 is disposed on the branch cables 11u and 11w connected to the U phase and the W phase of the distribution line C1 on the primary side of the cutout 13 with the three-pole interlocking opening function. Has been.

  When a short-circuit current exceeding the specified value flows through the distribution line C1 due to the short circuit of the reactor, the fuse element (not shown) of the current limiting fuse 14a is melted so that the load side of the cylindrical cutout 14 in the branch cables 11u and 11w becomes Current limiting is interrupted.

  The three-pole interlocking open function cutout 13 is attached to the primary side of the reactor 12 for the purpose of opening and closing the load current. The cutout 13 with the three-pole interlocking opening function is configured to open three poles at the same time when one of the three poles is blown by the discharge fuse 13a.

  As shown in FIG. 4, the cutouts 13 with the three-pole interlocking opening function are respectively arranged on the branch cables 11u, 11v, and 11w that are branched and connected to the U-phase, V-phase, and W-phase of the distribution line C1. The three box-shaped cutouts 13u, 13v, and 13w are provided.

  Here, the rated currents of the discharge-type fuse 13a and the current-limiting fuse 14a are set so that the rated current of the discharge-type fuse 13a is smaller than the rated current of the current-limiting fuse 14a.

  Next, the protection function of the reactor 12 will be described. For example, when a short-circuit fault occurs in the reactor 12, the short-circuit current generated by this fault is suppressed to a value equal to or less than the cutoff short-circuit capacity of the cutout 13 with the three-pole interlocking open function by the current limiting fuse 14a in the cylindrical cutout 14. Thus, the discharge-type fuse 13a of a certain phase is blown out before the current-limiting fuse 14a. When the discharge fuse 13a of a certain phase is blown, the distribution line side of the reactor 12 is collectively opened. As a result, it is possible to limit the failure section, avoid a single-phase operation state, and prevent malfunction of the ground fault relay.

  In this switchgear 30 with a protective function, the current limiting fuse 14a and the discharge fuse 13a of the cutout 13 with the three-pole interlocking opening function are always blown before the current limiting fuse 14a of the cylindrical cutout 14 is blown. Protection coordination with the discharge-type fuse 13a is achieved. By this protection coordination, the reactor 12 is not charged only in one phase or two phases. That is, a phase failure condition (phase failure) does not occur, and a malfunction of the ground fault relay (ground fault relay) and a trip of the substation circuit breaker are also prevented.

It is a schematic diagram which shows schematic structure of the power distribution system which is Embodiment 1 of this invention. It is a schematic diagram which shows the state by which the switching of the distribution system was performed in the power distribution system shown in FIG. It is a schematic diagram which shows schematic structure of the road reactor apparatus used for the power distribution system shown in FIG. It is a figure which shows schematic structure of the switchgear with a protective function applied to the road reactor apparatus shown in FIG. It is a figure which shows schematic structure of the conventional power distribution system. It is a figure which shows the state by which the switching of the power distribution system was performed in the power distribution system shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power distribution system 2 Switchgear 3 Protection device 4 Outer frame 5 Base 10, 20 Transformer 12 Reactor 13 Cutout with three-pole interlock open function 13a Discharge fuse 14 Cylindrical cutout constituting primary cutout 14a Current limiting fuse 30 Switchgear with protection function 100,200 Substation A1-A4, B1-B4, A1 ′, B1 ′ Distribution system C1-C9, W1-W9 Distribution line S11-S17, S21, S22, S26, S27, S31, S32, S36, S37, S41, S42, S46, S27 Switch RC1-RC9 Road reactor device RW1-RW9 Aerial reactor device

Claims (13)

  A power distribution system having a reactor that compensates for a ground fault current from a distribution line, and in which road reactor devices arranged on the ground are distributedly arranged corresponding to the size of the ground capacitance of the distribution line.   The power distribution system according to claim 1, wherein the road reactor device is provided for a distribution line formed by a cable disposed in the ground.   The power distribution system according to claim 1 or 2, wherein the road reactor device changes the size of the reactor in accordance with the size of the ground capacitance of the distribution line.   The power distribution system according to claim 1 or 2, wherein the road reactor device has substantially equal reactors and is arranged in a sparse and dense manner according to a ground capacitance of the distribution line.   The power distribution system according to claim 1, wherein the road reactor device includes an opening / closing device that cuts off a load current between the distribution line and the reactor.   The power distribution system according to claim 5, further comprising a protection device that is connected between the switchgear and the reactor and that blocks a short-circuit current.   A primary cutout with a three-pole interlocking open function in which a discharge fuse is detachably mounted on the distribution line side of the reactor branched and connected to each phase of the distribution line, and a current limiting fuse with a cutoff function is detachable The power distribution system according to claim 1, further comprising a switchgear with a protective function in which a series circuit with the primary cutout is arranged.   The power distribution system according to claim 7, wherein the rated current of the discharge-type fuse is set smaller than the rated current of the current-limiting fuse. A reactor having a size corresponding to the capacitance to ground of the connected distribution line, and suppressing the flow of ground fault current;
An outer frame that covers and protects the reactor;
And a road reactor device arranged on the ground near the distribution line.   The switchgear provided between the distribution line and the reactor, which cuts off a load current from the distribution line, the switchgear is provided in the outer frame. Road reactor device.   The road reactor device according to claim 10, further comprising a protection device that is connected between the switchgear and the reactor and that cuts off a short-circuit current, and the protection device is provided in the outer frame.   A primary cutout with a three-pole interlocking open function in which a discharge fuse is detachably mounted on the distribution line side of the reactor branched and connected to each phase of the distribution line, and a current limiting fuse with a cutoff function is detachable The road reactor device according to claim 9, further comprising a switchgear having a protective function in which a series circuit with the primary cutout is arranged.   The road reactor device according to claim 12, wherein the rated current of the discharge fuse is set smaller than the rated current of the current limiting fuse.

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