JPH0260424A - spot network system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spot network system with improved spot network power receiving equipment.

[Conventional technology]

In general, spot network power receiving equipment has high reliability in power supply and is often used as power receiving and transforming equipment for buildings. The conventional SpotNets I/Work power receiving equipment was open at 57 hours.
As shown in Publication No. 68624, multiple branch buses are connected between a three-phase power supply and a common bus connecting loads, such as elevators, and a network transformer and a protector are connected to each branch bus. connected to current transformers, etc.

For example, in a current transformer, when a short circuit occurs in the A power supply bus of the power supply bus, a short circuit current flows to the short circuit accident point via the healthy 13 power supply bus - 13 branch bus common bus - A branch bus, and the short circuit current is In the A branch bus, a reverse current flows from the common bus to the power supply bus, and this current is detected by a current transformer.

The detected current activates the network relay, trips the protector circuit breaker, and protects the spot screw 1-work power receiving equipment, and this configuration is collectively referred to as a spot network protector.

On the other hand, if a short-circuit accident occurs on the load-side bus connected to the common bus, short-circuit current flows from the spot network power receiving line connected to the point of the short-circuit, and the tick-off circuit breaker on the load bus or the tick-off fuse The line is shut off and the accident point is cleared.

Also, if a short circuit accident occurs on the common bus, as above,
A short-circuit current flows into the fault point from multiple spot network power receiving lines, and the protector fuse connected to the network transformer secondary shuts it off, resolving the fault point. In this case, the protector fuses of all spot network power receiving lines are cut off, resulting in a total power outage for the equipment. Therefore, in order to reduce the probability of short-circuit accidents on the common bus, measures such as insulating the common bus with an insulating material, or making it a so-called insulated bus, are being taken.

[Problem to be solved by the invention]

In this spot network system, as shown in FIG. 5, when there is no communication switch 11 on the common bus 12, when a short circuit 13X occurs at the load, the network transformer 4A
Since the short circuit current is supplied from the four circuits of ~4D, the tick-off circuit breaker 13 is connected to the four network transformers 4A~
41) is required to withstand the short circuit current flowing from the terminal. This has led to an increase in the capacity of the tick-off circuit breaker 13, leading to a significant increase in equipment costs.

In addition, when inspecting the common bus 12, it is necessary to shut down the entire equipment, and in the age of advanced information technology, stopping power reception is not allowed. This has become an important issue that must be avoided.

The purpose of the present invention is to suppress short circuit current as capacity increases,
Another object of the present invention is to provide a spot network system that can completely power out equipment, shut down all equipment during inspections, and provide safety during inspections.

[Means to solve the problem]

The spot network system of the present invention provides a busbar communication switch on a common busbar, and automatically closes the busbar communication switch on the condition that the protector circuit breaker is disconnected.

[Effect]

If one of the spot network power receiving lines receives a shutdown command to the protector circuit breaker due to reverse power, for example, and the bus connection switch connected to the common bus is turned on at the same time, the spot network power receiving line simultaneously feeds power to the common bus. By making 1 line less than the maximum total line, the short circuit current on the load side is 1 line less than the total spot network line.
The line can have less short circuit current value.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1, 2, and 3.

Branch buses 2A to 2D from power company network relays IA to ID to consumers are connected.

Network 1-work transformer 4A-4 via disconnector 3A-3D
D, protector fuses 5A to 5■] are connected to common bus lines L2A to 12B via protector circuit breakers 6A to 6D. The common busbars 12A to 12B are connected via a busbar communication switch 11, and the common busbars 12A to 12B are connected to each other via a busbar communication switch 11.
Power is supplied to each load equipment via the tick-off circuit breaker 13. On the power supply side of the protector circuit breakers 6A to 6D and the common bus side, network relays 10A to IO are connected via voltage transformers 8A to 8D, 9A to 9D and voltage current transformers 7A to 7D.
D is connected.

Next, if a short-circuit accident IX occurs on this network distribution line IB, the short-circuit current will flow from the network distribution line IA to the network transformer 4A to the protector breaker 6A, through the common bus 12A, and from the protector breaker 6B to the network transformer. It flows to the accident point 1X via 4B. In this case, screw 1 to work relay 1. OB is operated by reverse power, and by tripping the protector circuit breaker 6B and simultaneously closing the busbar communication switch 11, the common busbar 12A is activated.

1 and 2B are connected, and power is supplied to the common bus from network transformers 4A, /Ic, and 4D, forming a three-line slot 1 to network power receiving equipment.

In other words, in the embodiment shown in Fig. 1, the equipment has four work power receiving lines to SPOTNET 1, and a maximum of three lines are connected to the common bus.
It is operated so that only the line is connected.

If a short circuit occurs at the short circuit point 13X on the load side of the tick-off circuit breaker 13, the short circuit current will flow through the network transformer 4. A, 4
．． 13, protector circuit breaker (e.g. 6I3)
F+? c. If a short circuit accident 13X occurs while the busbar communication switch 11 is turned on, the short circuit current will be:
It is supplied from network transformers 4Δ, 4C, 4, and D. Therefore, if a short circuit occurs at the short circuit point 13X, the short circuit current will be a current for only three lines at most. As described above, according to the present invention, it is only necessary to consider the short circuit currents flowing from the three network transformers, and the short circuit capacity of the tick-off circuit breaker can be greatly reduced.

Figure 4 shows an example of a so-called ring bus system in which the common bus is connected in a loop through busbar communication switches 11A to 11D, with busbar communication switches 11B and 11D turned OFF and ilA and 11C If you turn it on and use it, you can perform the same operation as shown in Figure 1. Also, if you turn IIA and 116 on
This is an example in which the same operation method can be achieved even if the FF, IIB, and 11D are turned on, and the effect of reducing the short-circuit current on the load side can be obtained.

Also, when inspecting the common bus 12A, the common bus 1113-1
This can be done while the 2D is running, which minimizes the range of power outages and enables safe inspection.
Since a considerable amount of power outage time is required for recovery, the common bus bar was an insulated bus bar, but in this example, the common bus bar is separated by a bus connection switch, so there is no possibility of a total power outage.
In addition, by opening the busbar connection switches at both ends of the short-circuited common busbar, other common busbar sections can be operated immediately, so there is no effect even if the busbar insulation is discontinued, which has a significant effect on reducing equipment costs. is obtained.

Although the above embodiment has been explained with 4-line power reception, the same can be said for 2 to 3 lines, 5 lines or more, by connecting the busbar communication switch to the common busbar and making the busbar a ring busbar. The effect of this can be obtained.

In addition, since the busbar communication switch is automatically turned on when any of the network power receiving lines is cut off, the installed capacity of the network transformer should be such that the total load capacity can be covered by one unit when it is not in use. .

〔Effect of the invention〕

As described above, according to the spot network 1 work system of the present invention, in addition to reducing the short circuit capacity of the tick-off circuit breaker, it is possible to avoid total power outage in the event of a common bus accident, and to ensure the safety of the common bus and total equipment power outage. In addition, it is possible to provide a system that does not require the use of common busbars, and it is also possible to eliminate the need for insulation of the common bus bar.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a spot network 1-work system b which is an embodiment of the present invention, FIGS. 2 and 3 are circuit diagrams of a conditional circuit used in this spot network system, and FIG.
The figure is a system diagram of a spot network system which is an embodiment of the present invention, and FIG. 5 is a system diagram showing a conventional example. 4A~4D...Network transformer, 6A~6D...
Protector circuit breaker, 10A to 10r)/Network relay, 11, IIA to 11D Busbar connection switch, 12
．． 12A to 12D... Common bus bar, 13... Tick-off circuit breaker. Chestnut 4 picture Yu S day

Claims (1)

[Claims] 1. Comprising a plurality of spot network power receiving lines connected to protector circuit breakers, a common bus connecting the power receiving lines, and a plurality of load distribution lines connected to the common bus. In spot network power receiving equipment,
A spot network system characterized in that a busbar communication switch is connected to a common busbar, and the busbar communication switch is turned on when a protector circuit breaker is cut off. 2. The common bus bar is divided and connected via a busbar communication switch, and a spot network power receiving line is connected to each divided common bus bar, as set forth in claim 1. Spot network system. 3. The spot network system according to claim 1, wherein the common bus is a ring bus connected in a loop, and the ring bus is divided and connected via a bus connection switch.