JP2000166084A - Distribution system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To instantaneously avoid accident for minimizing influences on a load in case of an accident by reducing the opening and closing times of a plurality of power switching devices and branch switches. SOLUTION: This system is provided with power switching devices 11, 12 for switching and connecting a plurality of power sources 1, 2 to a power line, branch switches 11a to 11c, 21a to 21c for interrupting current, which are disposed on a plurality of circuits distributed and formed from bus-bars 61, 62 branched from the load side of the power switching devices 11, 12, current detectors 41a to 41c, 51a to 51c for detecting currents running through the power switching devices and the respective branch switches, and a control means 100, which opens the power switching device for interrupting power supply, if an overcurrent exceeding the detected current value is identified, opens the ranch switch through which the overcurrent flows, and closes the power switching device to recover it to the condition before the overcurrent has occured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power distribution system for receiving power from a plurality of power sources and distributing the power to load devices in the facility, for example, in a facility such as a building or a factory.
In particular, the present invention relates to a power distribution system that improves power supply reliability by shortening the voltage drop time of a healthy part when an accident such as a short circuit occurs, and reduces the degree of equipment damage due to an internal accident.

[0002]

2. Description of the Related Art In a power distribution system in which a plurality of power supplies are connected to a power distribution system, for example, a power receiving facility that receives power using a normal standby power receiving method, a power receiving facility that has an emergency standby power generation facility in addition to the normal power receiving system, and the like. is there. FIG. 8 is, for example, “Electrical Engineering Handbook” edited by the Institute of Electrical Engineers of Japan. 1225, which is one of the power supply systems for extra-high voltage customers. As shown in FIG. 8, the normal standby switching system includes a 2DS-1CB system, a 2DS-2CB system,
There is a 2DS-PF system and the like. FIGS. 9 to 11 show, for example, the “High-voltage power receiving equipment guideline revised edition” P. 62 shows power receiving equipment using the main and backup lines described in 62 to 65. FIGS. 12 and 13 show, for example, the “High-Voltage Power Receiving Equipment Guideline Revised Edition” P. 65
66 shows a power receiving facility with an emergency standby power generating facility described in No. 66.

[0003] Among them, for example, the 2DS-1CB system will be described with reference to FIG. FIG. 14 shows first and second power receiving power sources S1, S2, first and second power switching devices SW1, SW2 connected to the first and second power receiving power sources S1, S2, and a power switching device. It comprises a normally closed main switch CBM connected to SW1 and SW2, and a plurality of branch switches CB1 to CB4.

Conventionally, a mechanical switch, a static switch using a semiconductor element, or the like has been used for the power supply switching devices SW1 and SW2 for two-system power reception. Conventional mechanical switches include an air switch, a vacuum switch, a gas switch, and the like, and a drive unit of the switch uses a spring accumulated force. When it is necessary to switch the power supply instantaneously, a static switch is often used, and a thyristor or an IG
BT (gate turn-off thyristor) and the like.

[0005] The conventional power supply switching device is intended to switch the power supply, and does not have the ability to interrupt a fault current such as a short circuit. Therefore, the normally closed main switch C having the ability to interrupt fault current such as short circuit on the load side of the power supply switching device
BM is arranged. A plurality of branch switches CB1 to CB4 having a breaking capacity suitable for the circuit are arranged on the load side to protect the circuit and the load from an accident such as a short circuit.

FIGS. 15 (a) and 15 (b) show, for example, P.M. of “High-voltage power receiving equipment guideline revised edition” published by Ohmsha. FIG. 154 is a simplified diagram of a part of the high-voltage power receiving equipment shown in FIG. 154 and shows the operation characteristics of the switch in the figure. This figure relates to a very general protection system for a high-voltage power receiving system.

Below a plurality of power supply switching devices, FIG.
The equipment as shown in FIG. Equipment below the receiving end is called premises equipment, and accidents below the receiving end are called premises accidents. In FIG. 15A, CBM is a main switch closest to the power receiving end, and CB1 is one of several first-layer branches (not shown) connected to a bus 1 located on the load side of the main switch CBM. Branch switch, CB11 is branch switch 2.
A branch switch of one of several not-shown second-tier branches connected to the bus 2 located on the load side of
CB111 is a branch switch of one of several third-layer branches (not shown) connected to the bus 3 located on the load side of the branch switch 3, and includes CTM, CT1, and CT.
11, CT111 is a current detector installed near each switch.

FIG. 15B shows the operating characteristics of each switch. For a certain current value If, the operating time of each switch is set to be longer for switches closer to the power supply. It indicates that. Such a protection scheme in which a switch closer to the power supply is set for a longer time is called a step-time protection scheme.

In FIG. 15A, when an accident occurs at an accident point A and an accident current If flows, a branch switch CB1 is turned on.
11 interrupts the current at the time t111 shown in FIG. At this time, the fault current also flows through the main switch CBM and the branch switches CB1 and CB11, but since the operation time is set to t111 or more as shown in FIG. 15B, the respective switches do not operate. .

When a short circuit fault or the like occurs at the fault point B, no fault current flows through the branch switches CB11 and CB111, so that the respective switches do not operate nor need to operate. This fault current is cut off by the branch switch CB1, but in this power distribution system, the operation time of the branch switch CB1 is set to t1, so that the switch can operate at time t4 or less. Nevertheless,
The accident cannot be eliminated during the time t1. As described above, since a switch closer to the power supply has a time limit added to the operation, the accident continues for a long time, and there is a problem that damage such as equipment damage is increased.

In order to solve the above-mentioned problem, there is, for example, Japanese Patent Application No. 9-185445. This solves the problem of the so-called step-time protection method in which the operation time of each switch is set in advance.If an accident occurs in any part of the distribution system, its duration or sound circuit The voltage drop time of the power supply is greatly reduced, the reliability of power supply is improved, the damage caused by the arc at the accident location is reduced, and the pressure rise inside the power distribution device due to the arc is reduced.

In the configuration shown in FIG. 15A, the main switch CBM, branch switches CB1, CB11, CB11
Current detectors CTM, CT1, CT11, C
T111 is provided, and each detection output is sent to a centralized monitoring and control device (not shown). When a current equal to or more than a set value flows through a predetermined branch switch in the event of a short circuit, the centralized monitoring and control device immediately sends an opening command to the main switch CBM to open the pole and cuts off the current.

Immediately after that, an opening command is sent to a branch switch located immediately above the location of the accident to open the circuit to open the electric circuit, and thereafter the main switch CBM is closed again. Using a switch with a short operation response time (opening / closing time) as the main switch and branch switch, and performing the above-mentioned control, a very short time no matter where the accident occurs Thus, an accident can be avoided and the voltage at a healthy part can be restored.

[0014]

In the conventional power distribution system, as described above, since the operation time of each switch is a so-called step time protection method in which the operation time of each switch is set in advance, as described above, for example, an accident occurs at an accident point B. If it occurs, t1
For example, the accident continues, and for example, a voltage drop occurs in a system connected to a branch switch (not shown) other than the branch switch CB1 connected to the bus 1 during t1.

In a conventional switch, for example, the accident duration time t1
Is about 0.5 s to 1 s, and the load equipment is seriously affected by such a voltage drop over time. For example,
As shown in FIG. 16, when a ground fault or the like occurs at the fault point B, the voltage of the circuit distributed and connected to the bus 23 occurs for the duration of the fault. In addition, equipment is damaged by the accident arc, the degree of which depends on the duration of the accident,
The longer the time, the greater the degree of damage.

In general, such a power distribution system is used by being housed in a housing. If the accident point is, for example, inside the housing, the pressure inside the housing is caused by an accident arc. And the housing needs to have a structure having sufficient strength against the pressure increase. Alternatively, in a power distribution system that receives power from a plurality of power sources, when an accident occurs on the power source side and the voltage drops, it is possible to reduce the effect of the voltage drop of the device by switching to another power source. However, when an accident occurs in the above system, there is a problem that the accident continues for a long time.

As means for solving the above problems,
For example, there is Japanese Patent Application No. Hei 9-185445, which cannot deal with an accident occurring on the power supply side, resulting in a long-term voltage drop. In addition, when such a system is introduced into a power distribution system that receives power from a plurality of power sources, the power switching device does not have a breaking ability, and an accident occurs between the power switching device and the power switching device and the main switch. In such a case, the accident continues for a long time and the voltage drops. Further, depending on the configuration of the system, simply introducing the above-described system may not allow coordination between the power supply switching device and the main circuit breaker, and may increase the time of an accident or voltage drop.

The present invention has been made in order to solve the above-described problems, and by shortening the opening / closing time of a plurality of power supply switching devices and branch switches, any accident can be prevented. It is an object of the present invention to provide a low-cost power distribution system capable of instantly avoiding an accident and minimizing the influence on a load.

[0019]

According to a first aspect of the present invention, there is provided a power distribution system having a power supply switching device for switching and connecting a plurality of power supplies to a power line, and a state in which the power supply switching device is not connected to any power supply. A current interrupting branch switch arranged in each of a plurality of circuits distributed and formed in at least one or more stages from a bus branched from the load side of the power switching device, and a current flowing through the power switching device and each branch switch. A current detector to be detected and a branch switch in which an excessive current flows are opened after the power supply switching device is opened and power supply is cut off when an excessive current is determined based on the current value detected by the current detector. Control means for controlling the power supply switching device so as to close the power supply switching device again after the opening and to return to the state before the occurrence of the excessive current.

[0020] In the power distribution system according to the second aspect of the present invention, the shutoff capability of the power supply switching device is greater than the shutoff capability of the branch switch. When it flows, the power supply switching device is opened to disconnect the power supply from the branched bus.

In the power distribution system according to the third aspect of the present invention, the control means specifies one or a plurality of branch switches to be opened based on the current values detected by the plurality of current detectors. If the current flowing through the specified branch switch is within the breaking capability of the specified branch switch, an opening command is sent to the specified branch switch; otherwise, the power supply switching device A disconnection command is sent to the power supply and the load side is disconnected, and immediately after that, an opening command is sent to the specified branch switch. And a centralized monitoring and control device for returning to the normal state.

In the power distribution system according to a fourth aspect of the present invention, when the current detected by the current detector disposed in the power supply switching device is equal to or greater than a set value, the control unit instantaneously opens the power supply switching device. Based on the control device that sends commands and disconnects the power supply from the load, and the fault current detected by the current detectors arranged in each of the plurality of branch switches, it is closest to the fault location and the power receiving side of this fault location A centralized monitoring and control device that specifies a branch switch to be opened corresponding to the above, sends an opening command to the specified branch switch, sends a closing command to the power supply switching device, and returns to a state before the accident. It is provided with.

In the power distribution system according to the fifth aspect of the present invention, the control means is supplied with a detection output of a current detector connected to the load side of the power supply switching device, and performs an accident determination in accordance with the detection output to perform an accident determination. A main individual accident determination controller that opens or closes the power supply switching device according to a command from the outside, or a switching device, and is provided corresponding to each branch switch and connected to the branch switch. A detection output of the current detector is supplied, an accident determination is performed according to the detection output, and the operation of the corresponding branch switch is determined based on its own current interrupting capability. And a slave individual accident determination controller that opens a corresponding branch switch after sending an opening command to the main individual accident determination controller.

In the power distribution system according to the sixth aspect of the present invention, the control means, when sending the opening command to the branch switch after sending the opening command to the power switching device, interrupts the current by the power switching device. After confirming that the switching has been performed, an opening command is sent to the branch switch.

According to a seventh aspect of the present invention, there is provided a power distribution system having opening detection means for detecting an opening of a plurality of branch switches.
The control means, when sending a closing command to the power supply switching device after sending the opening command to the plurality of branch switches, based on the detection output of the opening detection means, After confirming the opening, a closing command is sent to the power switching device.

In the power distribution system according to the present invention, the opening time of at least one of the power supply switching device and the plurality of branch switches is 10 ms or less.

In the power distribution system according to the ninth aspect, the closing time of at least one of the power supply switching device and the plurality of branch switches is 10 ms or less.

[0028] In the power distribution system according to the tenth aspect of the present invention, at least a part of the power supply switching device and the plurality of branch switches are constituted by semiconductor switches using semiconductor switching elements.

In the power distribution system according to the eleventh aspect, at least a part of the power supply switching device and the plurality of branch switches are constituted by a high-speed switch using an electromagnetic repulsive force in the switching mechanism. is there.

In the power distribution system according to the twelfth aspect, at least a part of the power supply switching device and the plurality of branch switches include a semiconductor switch using a semiconductor switching element and a high-speed switch connected in parallel to the semiconductor switch. It is a thing.

In the power distribution system according to the thirteenth aspect, at least one of the opening mechanism and the closing mechanism of the high-speed switch is directly driven by a repulsive force between high-frequency currents supplied from an external power supply or eddy currents. It is driven in a typical manner.

In the power distribution system according to the fourteenth aspect of the present invention, at least some of the contact portions of the power supply switching device and the plurality of branch switches are provided as a spring mechanism for maintaining a closed state or an open state at a predetermined pressure. It has a flat spring.

[0033] In the power distribution system according to the fifteenth aspect, at least some of the contact portions of the power supply switching device and the plurality of branch switches are constituted by vacuum switch tubes.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a simplified single-line diagram of a power distribution system according to Embodiment 1 of the present invention. In the figure, SW1 (11) and SW2 (12) are power switching devices, and the power switching devices SW1 (11) and SW2
In (12), the fault current is interrupted by using the electromagnetic repulsion, and the closing / opening time when interrupting the fault current and the switching time when switching the power supply can both provide a high-speed response of about several ms.

CB1 (11a) to CB3 (11c) are branch switches. These branch switches CB1 (11a) to CB3 (11c)
B3 (11c) is a power switching device SW1 (11) and SW
2 (12) is connected to a branch circuit branched from the first bus A (61) connected to the load side. Branch switch CB
1 (11a) to CB3 (11c) use electromagnetic repulsion,
High-speed response of about several ms is possible for both closing and opening.
The current breaking capability of the branch switches CB1 (11a) to CB3 (11c) may be lower than that of the power switching device.

CB11 (21a) to CB13 (21c)
Is a branch switch, and this branch switch CB11 (21
a) to CB13 (21c) are branch switch CB3 (11
It is connected to a branch circuit branched from the second bus B (62) connected to the load side of c). Branch switch CB11
(21a) to CB13 (21c) use electromagnetic repulsion,
A high-speed response of about several ms is possible for both closing and opening times. These branch switches CB11 (21a) to CB13
The current interruption capability of (21c) is determined by the branch switch CB1 (11
a) to CB3 (11c), similarly to the power switching device SW1
(11) It may be lower than SW2 (12).

The power switching devices SW1 (11), SW
2 (12), branch switches CB1 (11a) to CB3 (1
1c), CB11 (21a) to CB13 (21c)
For example, a high-speed switch that generates electromagnetic repulsion by the action of high-frequency currents supplied from an external power supply or by eddy currents caused by the high-frequency currents.

Reference numerals 31 and 32 denote power switching devices SW1 (1
1), current detectors 41a to 41c for detecting a current flowing in a circuit provided on the load side of SW2 (12), and current detectors 41a to 41c provided on the load side of branch switches CB1 (11a) to CB3 (11c), respectively. The detectors 51a to 51c are branch switches CB11 (21a) to CB13 (21c), respectively.
This is a current detector installed on the load side.

It should be noted that the current detectors 31 and 32 may be shared as long as there is separate information that either the power supply switching device SW1 (11) or SW2 (12) is connected to the power supply. In addition, these current detectors 31, 32, 41a
To 41c and 51a to 51c may be installed on the power supply side of the corresponding branch switch.

Reference numeral 31 denotes a load connected to the branch switch 11a, and reference numeral 32 denotes a load connected to the branch switch 21a.
It should be noted that the dotted line on the load side of the branch switch in the figure indicates that a load, a bus, and the like are connected.

Reference numeral 100 denotes a centralized monitoring and control device, which connects the current detectors 31, 32, 41a to 41c, 51a to 51c to signal lines 72a, 72b, 82a to 82c, 92a to 9c.
2c, information about the current is sent, and the control lines 71a, 71b, 81a to 81c, 91a to 91c
Power switch SW1 (11) or SW2 (1
2), each branch switch CB1 (11a) to CB3 (11
c) An opening command and a closing command are sent from the centralized monitoring and control device 100 by the CBs 11 (21a) to CB13 (21c), and contact information of each switch is sent to the centralized monitoring and control device 100.

Next, the operation of this embodiment will be described. In FIG. 1, loads 31L and 32L are connected to a power supply 1 by a power supply switching device 11 and branch switches CB1 (11a) to CB.
3 (11c), CB11 (21a) to CB13 (21
c).

FIGS. 2 (1) to 2 (4) are timing charts for explaining the operation of the power distribution system shown in FIG. 1. Assuming that a short circuit has occurred at the fault point B in FIG. I have. FIG. 2 (1) shows a fault current waveform flowing to fault point B through a circuit composed of power supply switching device 11 and branch switches 11c and 21c in FIG. 1 due to the occurrence of a short circuit fault at fault point B. However, for simplicity, only one phase of a normal three-phase circuit is shown.

FIG. 2 (2) is a waveform showing the open / close state of the power supply switching device (main switch 1) 11, FIG. 2 (3) is a waveform showing the open state of the branch switch 11c, and FIG. 2 (4). Is the load 31
5 is a waveform in which a circuit voltage applied to L is expressed as a normal voltage of 100%.

First, an accident occurs at time t1, and FIG.
The large current shown in (1) flows through the circuit. This fault current is detected by the current detectors 31, 41c, 51c, and is not detected by, for example, the current detectors 41a, 41b, 51a, 51b. The detection outputs of these current detectors 31, 41c, 51c are sent to the centralized monitoring and control device 100 via signal lines 72a, 82c, 92c.

The centralized monitoring and control apparatus 100 determines that an accident has occurred at time t2 because the fault current (see FIG. 2A) has exceeded the current level I1, for example, and immediately Sends the opening command. Since the power supply switching device 11 is a high-speed response switch using electromagnetic repulsion, the contacts are separated at time t3 in a short opening time of time t1, and an arc is generated.

The centralized monitoring and control device 100 sends an opening command to the power supply switching device 11 and also controls the branch switches 11a to 11
c, current detectors 41a-4 connected to 21a-21c
The location where the accident has occurred is specified based on information from 1c, 51a to 51c, and the like. In this case, the current detectors 41c, 51
c, the fault current is detected, and no fault current is detected by the other current detectors. Therefore, a fault has occurred on the load side of the current detector 51c. Unit 21c determines that it is necessary to open the circuit.

The power supply switching device 11 has a necessary interruption capability for an accident current flowing due to an accident occurring on the load side. Branch switches 41a to 41c, 21a to 2
In the case 1c, even if an accident occurs on the load side, the electric current is interrupted by the power supply switching device 11, so that it is not necessary to have an interrupt current interrupting ability.

When it is confirmed from the detection signals of the current detectors 31, 41c and 51c that the power supply switching device 11 has interrupted the fault current at the time t2, the centralized monitoring and control device 100 immediately specifies in advance after the time t2. An opening command is sent to the branch switch 21c to be opened next. Assuming that the time when the opening command is transmitted is t5, the branch switch 21 is started from that time.
The centralized monitoring and control device 100 sends a closing command to the power supply switching device 11 at a time t8 obtained by adding the time t4 and the allowance time t5 that the distance between the contacts of c becomes sufficient with respect to the circuit voltage. At this time, while the accident continues, another power source S2
Since it should not lead to (2), it is necessary to provide an interlock so that a closing command is never sent to the power supply switching device 12.

At time t6, the centralized monitoring and control device 100 detects that the branch switch 21c has been opened as instructed, for example, by an auxiliary contact as opening detection means of the branch switch 21c. The time of t4 + t5 is counted. After sending the closing command to the power switching device 11, at time t9 after the closing time t6 of the power switching device 11, the contacts of the power switching device 11 are electrically connected, and all of the branch switch 21c other than the load side are connected. The voltage returns to the circuit of. Note that t7 is a time when the distance between the contacts of the branch switch 21a becomes sufficient for the recovery voltage.

The voltage applied to the load during these series of operations will be described. At time t1 when the load leads to a so-called healthy circuit, an accident occurs and the power supply switching device 11
Until the fault current is cut off at time t4, the voltage drops to a voltage determined by the circuit constant. After the power supply switching device 11 cuts off the current, the voltage of the load becomes zero, and this state continues until the next time the power supply switching device 11 closes. Will return completely.

The duration of the voltage drop of the load will be described. In a high-speed response switch using electromagnetic repulsion, for example, the opening time is about 1 ms, and the closing time is about 5 ms. If the opening time is about 1 ms, the fault current can be cut off in a half cycle of the commercial frequency, so that the time from the occurrence of the fault until the fault current is cut off is about 10 ms.

The time t2 at which the centralized monitoring and control device 100 confirms the current interruption is almost zero, an opening command is sent to the branch switch 21c, the time t3 until opening starts is 1 ms, and the opening of the branch switch 21c is completed. 2ms, time to spare t
Assuming that 5 is 2 ms and then the time t6 required to close the power supply switching device 11 is 5 ms, it is about 20 ms from the occurrence of an accident until the power supply switching device 11 is closed again.

Next, consider the case where an accident occurs at the accident point A in FIG. In this case, the centralized monitoring and control device 100 uses the information sent from each current detector to switch the branch switch 1.
An accident has occurred between 1c and the branch switches 21a to 21c, and it is determined that the switch to be opened is the branch switch 11c. In this case, in the timing chart of FIG. 2, it is determined that the operating switch is the branch switch 11c instead of the branch switch 21c. In this case, in the timing chart of FIG. 2, the operating switch is the branch switch 11c instead of the branch switch 21c. In this case as well, the time required for the voltage applied to the load of the sound circuit to fall is exactly the same as that in the case where an accident occurs at the accident point B.

As described above, according to the power distribution system shown in FIG. 1, the fault can be eliminated in a short time of, for example, 10 ms regardless of the location of the fault in the power distribution system, and the voltage drop time of the load of the sound circuit can be reduced. It can be as short as about 20 ms. According to the power distribution system shown in FIG. 1, when an accident occurs, first, the power supply switching device 11 or 1
The current is cut off by the opening of 2, and then a predetermined branch switch is opened to open the electric circuit. However, when the predetermined branch switch has the ability to cut off the fault current, Alternatively, the current may be cut off by opening only the predetermined branch switch without opening the power supply switching device 11 or 12.

The centralized monitoring and control device 100 grasps whether the power supply switching devices 11 and 12 are connected to the power supply 1 or the power supply 2 based on the state of the power supply switching devices 11 and 12. That is, while the accident continues on the load side, an interlock function is provided so that the power supply switching device that has been opened before the occurrence of the accident is not closed to switch the power supply. In addition, when the voltage drops on the power supply side, the centralized monitoring and control device 100 switches the power supply to another power supply without operating each branch switch on the load side. In the present embodiment, the case where the load is connected to the power supply 1 via the power supply switching device 11 has been described, but the same applies to the case where the load is connected to the power supply 2 via the power supply switching device 12. Further, in the present embodiment, the case where there are two power sources has been described, but the same applies to the case where there are a plurality of power sources.

Embodiment 2 FIG. 3 shows a configuration of a power distribution system according to Embodiment 2 of the present invention. 3, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. The output of the current detector 31 installed on the secondary side of the power switching device 11 is input to the power switching device controller 110, and the power switching controller 110 directly opens and closes the power switching device 11. It is configured to be able to send commands. Similarly, the output of the current detector 32 installed on the secondary side of the power supply switching device 12 is input to the power supply switching device controller 110, and the power supply switching controller 11
0 is configured so that an opening / closing command can be sent directly to the power supply switching device 12.

Further, the power supply switching device controller 110
The signal line 73 is connected to the centralized monitoring and control device 100, and can exchange current detector information and control signals. Other configurations of the power distribution system shown in FIG. 3 are the same as those of the power distribution system shown in FIG. In the present embodiment, the case where the load is connected to the power supply 1 via the power supply switching device 11 has been described, but the same applies to the case where the load is connected to the power supply 2 via the power supply switching device 12. In the present embodiment,
Although the case where there are two power supplies has been described, the same applies to the case where there are a plurality of power supplies.

Next, the operation of this embodiment will be described. For example, when an accident occurs at the accident point B in FIG. 3, when the current detector 31 detects the accident current, the power supply switching device controller 110 connected to the current detector 31 determines that the accident has occurred, Instantly to the power switching device 11,
Sends the opening command. At the same time, centralized monitoring and control device 1
For 00, the current information or the information relating to the transmission of the opening command to the power supply switching device 11 is transmitted. The subsequent operation of shutting off the power supply switching device 11 is the same as that of the power distribution system shown in FIG. 1 and the effect is the same as that of the power distribution system shown in FIG.

Embodiment 3 FIG. 4 shows a power distribution system according to Embodiment 3 of the present invention. In FIG. 4, portions corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. The power distribution system shown in FIG. 4 is largely different from the power distribution system shown in FIG. 1, for example, in that an individual accident determination controller 120 is provided for power supply switching devices 11 and 12. The individual accident determination controller 120 is connected to the current detectors 31 and 32 to obtain current information, and transmits an open / close control signal to the power switching devices 11 and 12 via the signal lines 131a and 132a. It is configured to be able to.

Similarly, branch switches 11a to 11c, 21
a to 21c correspond to the individual accident determination controllers 123a to 123c.
The difference is that 123c and 122a to 122c are provided. Then, for example, the individual accident determination controller 1
23a to 123c and 122a to 122c are individual accident determination controllers 123a to 123c and 122a corresponding to the branch switches 11a to 11c and 21a to 2c located on the load side of the corresponding branch switches 11a to 11c and 21a to 2c. ~
122c so that information can be exchanged with the signal line 14c.
1a to 141c and 151a to 151c.

Further, the individual accident determination controllers 123a-1
23c is an individual accident determination controller 12 corresponding to the power supply switching device 11 located on the power supply side of the branch switches 11a to 11c.
0 so that information can be exchanged with the signal lines 143a to 143a-1.
43c. In the present embodiment, the case where the load is connected to the power supply 1 via the power supply switching device 11 has been described, but the same applies to the case where the load is connected to the power supply 2 via the power supply switching device 12. Further, in the present embodiment, the case where there are two power sources has been described, but the same applies to the case where there are a plurality of power sources.

Next, the operation will be described. When an accident occurs at an accident point A or B in FIG. 4, the current detector 41c
Detects the fault current. The subsequent operation of the individual accident determination controller 123 will be described with reference to the flowchart of FIG.

First, when an accident occurs (step S
1), the individual fault judgment controller 123 for the fault current
Is determined to be able to shut off, that is, whether the fault current is equal to or higher than the interrupting capability of the branch switch 123 (step S).
2). In the case of such a power distribution system, the power supply switching device 120 has a maximum current of an accident that occurs in the power distribution system.
Can be interrupted, and the branch switch 11c does not need to have an interrupting capability for the maximum current.

Thereafter, the location of the accident is identified, that is, it is determined whether the accident is between the branch switch 11c and the branch switches 21a to 21c or whether the accident is on the load side of the branch switches 21a to 21c (step S3). To this end, the power supply switching device 120 determines based on information from the individual accident determination controllers 122a to 122c, that is, whether or not the load-side current detectors 51a to 51c have detected an accident current.

If there is no information from the individual accident determination controllers 122a to 122c, the accident point is between the branch switch 11c and the branch switches 21a to 21c, for example, as at the accident point A, and there is information. In the case, the branch switches 21a to 21
An accident at the load side of c, for example, an accident at the accident point B.

If the fault current is within the shut-off capability of the branch switch 11c and the fault location is, for example, fault point A, the branch switch 11c is turned off and the power supply side The fact is notified to the accident determination controller 120 (steps S4 and S6). For example, when the accident at the accident point B is within the breaking capacity of the branch switch 11c, and when the branch switch 11c breaks, it exceeds the breaking capability of the branch switch 21c, and the individual accident determination controller 1
If the connection is made without operation from the switch 22c, the branch switch 11c shuts off and sends state information to the power supply side (steps S5 and S6).

Next, a case where the fault current is equal to or higher than the breaking capability of the branch switch 11c will be described. When there is no information from the individual accident determination controllers 21a to 21c on the load side, for example, when it is determined that an accident has occurred at the accident point B, it is necessary to cut off the accident current with the power supply switching device 11, Power supply switching device 11 to individual accident determination controller 120
, That is, the status information is communicated.

In this case, since the branch switch 21c is closest to the accident point and located on the power supply side,
After the power supply switching device 11 completes the cutoff, the branch switch 21c releases the circuit. Then, the fact that the circuit has been released is notified to the individual accident determination controller 120, and the power switching device 11 is given a re-start permission. Branch switch 2 in case of accident at accident point B
When 1c is shut off, the branch switch 11c does not operate and sends state information to the individual accident determination controller 120 of the power supply switching device 11. If the branch switch 21c does not shut off, the individual accident determination controller 12 of the power supply switching device 11
Send status information to 0. The power switching device 1
Although the individual accident determination control devices 120 of 1 and 12 are the same as described above, they can be provided separately. However, in this case, some kind of interlock-related information transmission function is required.

Embodiment 4 FIG. 6 shows a power distribution system according to Embodiment 3 of the present invention. 6, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the present invention, the power supply switching device 11
A, 12A, branch switches 110A to 110C, and branch switches 210A to 210C are configured by semiconductor switches using thyristor elements. Other configurations are the same as those of the power distribution system shown in FIG. In the present embodiment, the case where the load is connected to the power supply 1 via the power supply switching device 11A has been described, but the same applies to the case where the load is connected to the power supply 2 via the power supply switching device 12A. Further, in the present embodiment, the case where there are two power sources has been described, but the same applies to the case where there are a plurality of power sources.

The operation and effects of the power distribution system shown in FIG. 6 are the same as those of the power distribution system shown in FIG. In the power distribution system shown in FIG. 6, thyristor elements are connected in anti-parallel. However, in addition to thyristor elements, similar effects can be obtained by using a semiconductor switch element such as a GTO, IGBT, or diode. be able to.

Embodiment 5 FIG. 7 shows a power distribution system according to Embodiment 5 of the present invention. 7, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the present invention, the power supply switching device 11
B, 12B, branch switches 111A to 111C, and branch switches 211A to 211C each include a semiconductor switch using a thyristor element and a high-speed switch connected in parallel to the semiconductor switch. Other configurations are the same as those of the power distribution system shown in FIG. In the present embodiment, the case where the load is connected to the power supply 1 via the power supply switching device 11B has been described, but the same applies to the case where the load is connected to the power supply 2 via the power supply switching device 12B. Further, in the present embodiment, the case where there are two power sources has been described, but the same applies to the case where there are a plurality of power sources.

The operation and effects of the power distribution system shown in FIG. 7 are the same as those of the power distribution system shown in FIG. In the power distribution system shown in FIG. 7, thyristor elements are connected in anti-parallel, but a similar effect can be obtained by using a semiconductor switch element such as a GTO, IGBT, or diode in addition to the thyristor element. be able to.

At least the driving mechanism for opening or closing the high-speed switch may be directly driven by the repulsive force between the high-frequency currents supplied from the external power supply or the eddy currents. A configuration may be adopted in which a spring is provided as a spring mechanism for holding a part or all of the contact portions of the power supply switching device and the plurality of branch switches in a closed state or an open state at a predetermined pressure. A part or all of the contact portions of the power supply switching device and the plurality of branch switches may be constituted by a vacuum switch tube.

[0075]

According to the first aspect of the present invention, the fault current flowing in any fault on the load side in the power distribution system is first cut off by the power supply switching device, and thereafter,
The branch switch opens the circuit, and then the power supply switching device is closed again, and the voltage drop due to an accident occurring on the power supply side is instantaneously switched to another power supply by the power supply switching device. As a result, the duration of the accident and the voltage time of the sound circuit can be fixed and shortened for any accident in the distribution system, improving the reliability of power supply, reducing the degree of damage to the accident location, and This has the effect of reducing the pressure rise inside the switchboard.

According to the second aspect of the present invention, in the first aspect of the present invention, the shutoff ability of the power supply switching device is greater than the shutoff ability of the branch switch, so that a predetermined branch switch cannot be shut off by the branch switch. When a large amount of current flows, the power switch is opened to shut off the current and the power supply and load are disconnected. Does not need to have the shutoff capability, and has the effect of reducing the size and cost of the branch switch.

According to the third aspect of the present invention, in the first aspect of the present invention, the detection outputs of the plurality of current detectors are collected by the centralized monitoring and control device, and the centralized monitoring and control device specifies the location of the accident, and opens and closes the control target. The system is configured to control the power distribution equipment, so that it is possible to quickly detect and control accidents even in a complicated distribution system, and to obtain a power distribution system with high reliability of power supply and low damage to equipment and low pressure rise inside distribution equipment due to accidents. There is an effect that can be.

According to the invention of claim 4, according to claim 1,
According to the invention, since the control of the power supply switching device is made possible by the signal of the current detector close to the power supply switching device, there is an effect that the fault current interruption can be performed quickly and reliably.

According to the fifth aspect of the present invention, in the first or second aspect of the present invention, an individual accident judging device is provided corresponding to each switch, and each individual accident judging device is connected to a power supply of the individual accident judging device. It is configured so that information can be exchanged between the individual accident determination control device located on the side and the individual accident determination control device located on the load side,
Accident detection and control can be performed quickly even in complicated distribution systems, which has the effect of obtaining a power distribution system with high power supply reliability, low damage to equipment and low pressure rise inside distribution equipment due to accidents, and further expansion of the system. In addition, there is an effect that the power supply reliability can be improved at low cost as compared with a single centralized monitoring and control device.

According to the sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, the opening command to the branch switch is transmitted after confirming that the fault current has been interrupted by the power supply switching device. With such a configuration, there is an effect that the branch switch can be protected without generating an arc having a current value equal to or greater than the breaking capability between the contacts of the branch switch.

According to the seventh aspect of the present invention, in any one of the first to sixth aspects, it is confirmed that the power supply switching device cuts off the fault current and the branch switch opens the circuit by opening. Since the closing command is sent to the power supply switching device again from the beginning, there is an effect that the voltage can be restored by closing the power supply switching device after reliably removing the accident.

According to the invention of claim 8, according to claims 1 to 7,
In any one of the inventions described above, since part or all of the power switching device and the plurality of branch switches are switches having a short opening time, the duration of the accident and the integrity of the sound circuit for any accident in the distribution system The voltage drop time can be reduced uniformly and significantly, thereby improving the reliability of power supply, reducing the degree of damage to equipment at an accident location, and reducing the rise in pressure inside the switchboard.

According to the ninth aspect of the present invention, in any one of the first to eighth aspects, a part or all of the power supply switching device and the plurality of branch switches are switches having a short closing time. The voltage recovery after disconnection of the faulty circuit can be further speeded up, the voltage drop time of the healthy circuit can be greatly reduced, and the reliability of power supply can be increased.

According to a tenth aspect of the present invention, in the invention of the eighth or ninth aspect, a part or all of the power supply switching device and the plurality of branch switches are constituted by semiconductor switch elements. The effect is that the closing speed can be easily increased.

According to an eleventh aspect of the present invention, in the invention of the eighth or ninth aspect, the power supply switching device and a part or all of the plurality of branch switches are high-speed switches using an electromagnetic repulsive force in the switching mechanism. Therefore, there is an effect that opening and closing can be easily accelerated.

According to the twelfth aspect of the present invention, in accordance with the eighth or ninth aspect of the present invention, the switch comprises a semiconductor switch using a semiconductor switching element and a high-speed switch connected in parallel to the semiconductor switch. The poles and closing poles can be easily made, and there is an effect that it is possible to reduce the power consumption and reduce the size as compared with a configuration using only semiconductor switching elements.

According to a thirteenth aspect of the present invention, the high-speed switch according to the eleventh or twelfth aspect, wherein the electromagnetic repulsive force is generated by the action of high-frequency currents supplied from an external power supply or by eddy currents caused thereby. Therefore, there is an effect that the speed of opening and closing can be easily increased.

According to the fourteenth aspect of the present invention, in the eleventh or twelfth aspect of the present invention, a flat spring is provided as a spring mechanism for holding the contact portion in a closed state or an open state at a predetermined pressure. There is an effect that poles and closings can be easily speeded up and realized at low cost.

According to the fifteenth aspect of the present invention, in the invention of the eleventh or twelfth aspect, the use of the vacuum switch tube has an effect that the dielectric strength between the contacts can be increased and the power supply reliability can be increased.

[Brief description of the drawings]

FIG. 1 is a simplified system configuration diagram as Embodiment 1 of the present invention.

FIG. 2 is a timing chart showing an operation of the power distribution system shown in FIG.

FIG. 3 is a simplified system configuration diagram according to a second embodiment of the present invention.

FIG. 4 is a simplified system configuration diagram according to a third embodiment of the present invention.

FIG. 5 is a flowchart showing an operation of the system according to the third embodiment of the present invention.

FIG. 6 is a simplified system configuration diagram as Embodiment 4 of the present invention.

FIG. 7 is a simplified system configuration diagram as Embodiment 5 of the present invention.

FIG. 8 is a diagram showing a configuration of a conventional power distribution system.

FIG. 9 is a diagram showing a configuration of a conventional power distribution system.

FIG. 10 is a diagram illustrating a configuration of a conventional power distribution system.

FIG. 11 is a diagram showing a configuration of a conventional power distribution system.

FIG. 12 is a diagram showing a configuration of a conventional power distribution system.

FIG. 13 is a diagram showing a configuration of a conventional power distribution system.

FIG. 14 is a diagram showing a configuration of a conventional power distribution system.

FIG. 15 is a diagram showing a configuration of a conventional power distribution system.

FIG. 16 is a diagram showing a configuration of a conventional power distribution system.

[Explanation of symbols]

1, 2 power supply, 11, 12, 11A, 12A, 11B,
12B power switching device, 11a to 11c, 21a to 21
c, 110a to 110c, 210a to 210c, 111
a to 111c, 211a to 211c Branch switch, 31
L, 32L load, 41a-41c, 51a-51c
Current detector, 61, 62 bus, 71a, 71b, 81
a to 81c, 91a to 91c Controller, 72a, 72
b, 82a to 82c, 92a to 92c signal line, 100
Centralized monitoring and control device, 110 Power supply switching control device, 12
0, 120a to 122c, 123a to 123c Individual accident determination control device.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02H 3/36 H02H 3/36 D H02J 3/38 H02J 3/38 LF (72) Inventor Yukimori Kishida 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation F-term (reference) 5G058 EE03 EF02 EH02 5G066 HA01 HA06 HA13 HA24 HB01

Claims (15)

[Claims] 1. A power supply switching device for switching and connecting a plurality of power supplies to a power line, wherein the power supply switching device has a state not connected to any power supply, and at least one power supply switching device is connected to a bus branched from a load side of the power supply switching device. A branch switch for current interruption arranged in each of a plurality of circuits distributed and formed in stages or more, a current detector for detecting a current flowing through the power supply switching device and each branch switch, and the current detector detects the current. At the time of judging an excessive current from the current value, after opening the power switch device to cut off the supply of power, open the branch switch in which the excessive current has flown, and after opening, close the power switching device again. A power distribution system, comprising: control means for performing control so as to return to a state before occurrence of an excessive current. 2. The shutoff capability of a power switch is greater than the shutoff capability of a branch switch. The control means opens the power switch when an excessive current that cannot be shut off by itself flows through a predetermined branch switch. The power distribution system according to claim 1, wherein the power supply is separated from the bus bar that is poled and branched. 3. The control means specifies one or a plurality of branch switches to be opened based on current values detected by the plurality of current detectors, and determines a current flowing through the specified branch switch. If it is within the shut-off capacity of the specified branch switch, it sends an opening command to the specified branch switch; otherwise, it sends an opening command to the power switching device and A centralized monitoring and control device is provided for disconnecting the load side and immediately after sending an opening command to the specified branch switch, sending a closing command to the power supply switching device and returning to a state before the occurrence of the accident. The power distribution system according to claim 1, wherein: 4. When the current detected by the current detector arranged in the power supply switching device is equal to or greater than a set value, the control means instantaneously sends an opening command to the power supply switching device to disconnect the power supply from the load. On the basis of the fault current values detected by the control device and the current detectors respectively arranged in the plurality of branch switches, a branch switch to be opened closest to the fault location and corresponding to the power receiving side of the fault location is specified. And a centralized monitoring and control device that sends a closing command to the power supply switching device after sending an opening command to the specified branch switch, and returns to a state before the accident. 2. The power distribution system according to 1. 5. The control means is supplied with a detection output of a current detector connected to a load side of the power supply switching device, determines an accident in accordance with the detection output, and opens the power supply switching device or from the outside. A main individual accident determination controller that opens or closes the power supply switching device in accordance with the command of the above, and a detection output of a current detector provided corresponding to each branch switch and connected to the branch switch is supplied. In accordance with this detection output, an accident determination is performed, and the operation of the corresponding branch switch is determined based on its own current interrupting capability, and if it is determined that there is no interrupting capability, the main individual accident determining controller opens the electrode. 3. The power distribution system according to claim 1, further comprising a slave individual accident determination controller that opens a corresponding branch switch after transmitting the command. 4. 6. The control means, after sending an opening command to the power switching device and then sending an opening command to the branch switch, after confirming that the current has been cut off by the power switching device, The power distribution system according to any one of claims 1 to 5, wherein an opening command is sent to the branch switch. 7. An opening detection means for detecting an opening of a plurality of branch switches, wherein the control means sends an opening command to the plurality of branch switches and then issues a closing command to a power supply switching device. 2. A transmission command is transmitted to the power switching device after confirming that an electric circuit is opened by the opening of the branch switch based on a detection output of the opening detection means.
The power distribution system according to any one of claims 1 to 6. 8. The power distribution system according to claim 1, wherein the opening time of at least one of the power supply switching device and the plurality of branch switches is 10 ms or less. 9. The power distribution system according to claim 1, wherein the closing time of at least one of the power supply switching device and the plurality of branch switches is 10 ms or less. 10. The power supply switching device and at least a part of the plurality of branch switches are constituted by a semiconductor switch using a semiconductor switching element.
Or the power distribution system according to 9. 11. The power supply switching device and at least a part of the plurality of branch switches are constituted by a high-speed switch using an electromagnetic repulsion force in a switching mechanism.
Or the power distribution system according to 9. 12. The power supply switching device and at least a part of the plurality of branch switches include a semiconductor switch using a semiconductor switching element and a high-speed switch connected in parallel to the semiconductor switch. 8
Or the power distribution system according to 9. 13. A driving mechanism wherein at least one of the opening and closing poles of the high-speed switch is directly driven by a repulsive force between high-frequency currents supplied from an external power supply or eddy currents thereby. The power distribution system according to claim 11. 14. A power supply switching device and at least a part of contact points of a plurality of branch switches are provided with a flat spring as a spring mechanism for holding a closed state or an open state at a predetermined pressure. The power distribution system according to claim 11 or 12, wherein 15. The power distribution system according to claim 11, wherein at least some of the contact portions of the power supply switching device and the plurality of branch switches are formed of a vacuum switch tube.