JPS5967832A - Automatic power source switching device - 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 [Technical Field of the Invention] The present invention relates to an automatic power supply switching device for a multi-line power receiving system power system.

[Technical background of the invention]

FIG. 1 shows an example of a dual-stage power receiving system power system to which a conventional automatic power switching device is applied.

The power receiving power sources are the first power receiving power source pi and the second power receiving power source P2.
From the grid, the first power receiving bus Bl is connected via the first and second power receiving switches 1 and 2, respectively.

The second power receiving bus B2VC is connected. A power receiving bus connection switch 3 is connected between the first and second power receiving bus lines Bl and 82.
It is connected to many parts. Further, first and second electric motors 6 and 7 are connected to the first power receiving bus B1 and the second power receiving bus 132K via first and second load switches 4 and 5, respectively.

Furthermore, first and second transformers 8 and 9 are connected to the first and second load switches 4 and 5 via first and second transformer-secondary breakers 10.11. There is. This first and second
The varnish sides of the transformers 8 and 9 are connected to the first distribution bus B11 via the first and second transformer secondary switches 12.13, respectively.
゜The second power distribution bus B21 is connected. The first distribution bus Bll and the second distribution bus ffMB 21 are connected to the distribution bus connection switch 14. The third and fourth electric motors 17
．． 18 are connected.

First power receiving bus B1. First and second undervoltage relays 21 and 22 are connected to the second power receiving bus B2 via first and second potential transformers 19 and 20, respectively. Still, the first distribution bus Bll and the second distribution bus B21 are connected via third and fourth potential transformers 23 and 24, respectively,
Third and fourth undervoltage relays;! 5.26 is connected.

Under normal system operation conditions, the first and second power receiving switches l,
The power receiving busbar connection switch 3 is closed, and the second power receiving switch 2 is open. Therefore, the first and second electric motors 6, 7
is the first power receiving bus Bl.

Power is supplied to the second power receiving bus B2. The third and fourth electric motors 17,18 are connected to the first and second transformers 8, 9 and the first power distribution (tl, line B11, second power distribution -fr).
J: Power is supplied via line B21.

Note that the power distribution busbar communication switch 14 is open.

” Under normal system operation conditions such as double-connection, if an accident occurs in the first power receiving system F1 indicated by the broken line, the first power receiving switch I is opened, and then the first power receiving switch I is opened. Switching is performed to close the second power receiving switch 2.

If an accident occurs in the first power receiving bus system FB7 surrounded by a dashed line in Fig. 1, the first power receiving switch 1
．． Power receiving busbar connection switch 3. The primary and secondary switches 10°J2 of the first transformer are each opened, and the distribution bus connection switch 14 is switched to close.

The first distribution system Fi indicated by the two-dot chain line in FIG.
If an accident occurs in 1, the first transformer primary switch 1
Switching is performed to open the 0 and 1st transformer secondary switches 12 and close the distribution bus connection switch 14.

[Problems with background technology]

In the power system described above, when the power supply is switched, the voltage on the bus separated from the fault system at the time of the power switch does not instantly become zero, but the residual voltage of the motor groups 6, 7, 17, and 18 increases. Occur. At this time, when the second power receiving switch 2 or the distribution bus connection switch 14 is closed, an inrush current flows into the system due to the voltage difference, phase difference, and frequency difference between the residual voltage and the power supply on the healthy system side. Therefore, transient torque caused by the rush current occurs in the motor groups 6, 7, 17.18, causing damage to the motor groups 6゜7, 17.18 and machines directly connected to these motor groups 6゜7, 17.18. Also, couplings etc. may be damaged.

In particular, when the phase difference is around 180°, a transient torque exceeding the rated torque may occur.

In order to reduce the above-mentioned transient torque, countermeasures (A) to Pe described below have been conventionally implemented.

(b) After the switch of the power receiving or distribution system in which the accident occurred is opened, the power receiving or distribution bus contact switch is immediately opened before the phase difference between the bus separated from the faulty system and the healthy system becomes large. 3゜14 is closed.

(b) Detect the phase between the residual voltage of the bus separated from the power receiving or distribution system where the accident occurred and the power supply of the healthy system,
Power receiving or distribution busbar connection switch 3.14 is turned on synchronously.

(c) After the switch of the power receiving or distribution system where the accident occurred is opened, the power receiving or distribution bus connecting switch 3 is opened after the residual voltage of the bus separated from the system where the fault has occurred has sufficiently attenuated.
．． 14 is closed.

However, in the method 0 described above, immediate closing is difficult due to factors such as the time required to close the switch and the operating time of the fault detection relay.

Therefore, the time required from opening the switch of the faulty system to closing the power receiving or distribution bus connecting switches 3 and 14 is 9.
．． The problem is that the required time is 3 to 0.5 seconds, and the phase difference becomes too large.

In the method (b), since there is a frequency difference between the residual voltage of the bus separated from the faulty system and the power supply of the healthy system,
The phase changes quickly. Therefore, even if synchronous phase is detected, there is a time delay in closing the switch, so there is a problem that the phase difference has already become large by the time the power receiving or distribution bus connection switches 3, 14 are closed. →
This method is the most commonly used power supply switching method, but it takes a long time for the residual voltage on the bus separated from the faulty system to sufficiently attenuate. Therefore, the stop time of the electric motor groups 6, 7, 17, and 18 is long, which poses a problem as a stain motor equipment. Particularly in large motor equipment, it takes 10 seconds or more for the residual voltage to sufficiently attenuate, which poses a problem.

[Purpose of the invention]

The present invention was made to eliminate the above problems, and
An automatic power supply system that can quickly switch power only to the necessary system according to the failure section of the power receiving power system, power receiving bus system, or power distribution system in a multi-line power receiving system, and reduce the inrush current that occurs when switching power sources. The purpose is to provide switching equipment +Vt.

[Summary of the invention]

The automatic power switching device according to the present invention is characterized by being configured as follows in order to achieve the above object. In other words, in a multi-line power receiving system power system, a series circuit consisting of a normally open auxiliary switch and an impedance element is
A power receiving system that connects in parallel a power receiving switch corresponding to a receiving power source and a power distribution bus connecting main switch, respectively, and detects a fault on the first receiving power source side and opens the corresponding first power receiving switch. An accident detection relay, and a distribution system accident detection relay that detects an accident in a first power receiving bus system and opens a first power receiving switch, a power receiving bus connecting main switch, and a switch provided in the first power distribution system, respectively. and an automatic power supply switching circuit in the event of a power receiving system fault, which is energized by the operation signal of the power receiving system fault detection relay and sequentially closes the auxiliary switch and the second power receiving switch provided on the second power receiving power source side. is energized by the operation signal of the power receiving bus fault detection relay to sequentially close the auxiliary switch provided on the second power receiving power source side and the second power receiving switch, and the power distribution bus connecting auxiliary switch and an automatic power switching circuit in the event of a fault in the power receiving bus system that sequentially closes the distribution bus contact main switches; and the power distribution bus contact auxiliary switch and the distribution bus contact main switch that are energized by the operation signal of the distribution system fault detection relay. and an automatic power supply switching circuit in the event of a distribution system fault, which sequentially closes the circuits.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained below with reference to the drawings.

In FIG. 2, the same parts as those in FIG. 1 are given the same reference numerals, and their explanations are omitted, and only the different parts will be explained.

The difference between FIG. 2 and FIG. 1 is that a series circuit consisting of a reactor 27 and an auxiliary switch 28 is connected in parallel to the second power receiving switch 2.

Similarly, a series circuit including a reactor 29 and an auxiliary switch 3o is connected to the power distribution busbar connection switch 14.

In FIG. 3, R-Fl is a contact point of a protective relay that detects an accident in the first power receiving system Fl, which is indicated by a broken line in FIG. R-FBI is a contact point of a protective relay that detects an accident in the first power receiving bus system FBI shown by a dashed line in FIG. R-Fll is a contact point of a protective relay that detects an accident in the first power distribution system Fil indicated by a two-dot chain line in FIG. Contacts R-Fl of these protective relays.

R-FBI and R-Fxi are power supply automatic switching device main body 31
It is connected to the.

This automatic power switching device main body 3 includes an automatic power switching circuit 32 in the event of a power receiving system failure. It is composed of a power receiving bus system power switching circuit 33 and a power distribution system automatic power switching circuit 34 in the event of a power failure.

Signals from the auxiliary contact 1a of the first power receiving switch 1 and the asthma R-Fl of the protection relay for detecting a power receiving system fault are input to the power receiving system automatic power switching circuit 32 at the time of a power receiving system fault.

The output of the power receiving system automatic power switching circuit 32 is sent to the auxiliary switch 28 and the second power receiving switch 2.

The abandoned power receiving bus system automatic power switching circuit 33 in the event of an accident includes the auxiliary contact 3a of the power receiving bus connection switch 3, the auxiliary contact 8a of the first transformer primary switch 8, and the first transformer secondary switch. 12
A signal is input from the auxiliary contact 12a of the power receiving bus system fault detection protection relay contact 1 (-FBI).

The output of this power receiving bus system fault automatic power switching circuit 33 is connected to the auxiliary switch 12. The second power receiving switch 2 and the power distribution bus connection switch 14 are sending out VC.

The automatic power switching circuit 34 in the event of a power distribution system fault includes an auxiliary contact 10a of the first transformer primary switch 10.

Signals are input from the auxiliary contact 12h of the first transformer secondary switch 12 and the contact R-Fll of the distribution system fault detection protection relay. The output of this automatic power supply switching circuit 34 in the event of a power distribution system fault is sent to the power distribution bus connection switch 14 and the auxiliary switch 30VC.

Next, the operation of the automatic power switching device configured as described above will be explained.

First, with reference to FIGS. 2 to 4, the first power receiving system F1
I will explain the effects P when an accident occurs. Fourth
The figure is a flowchart showing the operation procedure of this device in response to an accident in the power receiving system F).

When an accident occurs in the first power receiving system F1, the first power receiving system fault detection protection relay is activated and its contact R-F1 is closed. Further, the first power receiving switch is also opened, and its auxiliary contact 1a is closed.

The signal associated with the closing of the contact R-Fl and the auxiliary contact 1a is given to the power receiving system automatic power switching circuit 32 in the event of a power receiving system fault, and the following commands are given from the power receiving system fault automatic power switching circuit 32. It will be done.

That is, a closing command is given to the auxiliary switch 28. This circuit closing command causes the auxiliary switch 28 to close, and the second power receiving power source P2 and the second power receiving bus B2 are coupled at the axle 27, thereby reducing the rush current.

After a certain period of time has elapsed, the second power receiving switch 2 is closed, and the auxiliary switch 28 is opened, thereby completing the power switching operation.

Next, with reference to FIG. 2, FIG. 3, and FIG. 5, the operation when an accident occurs in the first power receiving line system FBI will be described. FIG. 5 is a flowchart showing the operation procedure of this device in response to an accident in the power receiving bus system FBJ.

When a 9 failure occurs in the first power receiving bus system FBI, the contact R-FB of the first power receiving bus system fault detection
J is closed. In addition, the first power receiving switch 1. Power receiving busbar connection switch 3. First transformer primary switch 10. The first transformer secondary switches 12 are each opened, and their auxiliary fd points 1a
.

,? a, 10a, and 12a are closed, and a signal associated with this closing is given to the automatic power switching circuit 33 in the event of a fault in the power receiving bus system. Then, the following commands are given from the automatic power supply switching circuit 33 in the event of a fault in the receiving bus system. That is, a closing command is given to the distribution busbar connection switch 14 and the auxiliary switch 28.

This closing command causes the distribution busbar communication switch 14 and the auxiliary switch 2R to close. According to the above, the second power receiving power source P2
and the second power receiving bus B2 and the first and second power distribution bus B2.
ll and B12 are coupled through a reactor 27 to reduce rush current. After a certain period of time has elapsed, the second power receiving switch 2 is closed. Furthermore, the auxiliary switch 28 is opened, and the power supply switching operation is completed.

Next, with reference to FIG. 2, FIG. 3, and FIG. 6, the action when an accident occurs in the first power distribution system Fil will be explained. FIG. 6 is a flowchart showing the operating procedure of this device in response to an accident in the first power distribution system FJJ.

When an accident occurs in the first power distribution system Fil, the contact R-F11 of the first power distribution system fault detection protection relay is closed. Also, the first transformer primary switch 10. The first transformer secondary switches 12 are each opened, and their auxiliary contacts 101L,
12a is closed, and a signal associated with this closing is given to the automatic power supply switching circuit 34 in the event of a power distribution system fault. Then, the following commands are given from the power supply automatic switching circuit 34 in the event of a power distribution system fault. That is, a closing command is given to the auxiliary switch 30. In response to this closing command, the auxiliary switch 30 closes the circuit. According to the above, the second distribution line 12 and the first distribution bus Bl
1 by a reactor 29 to reduce rush current. After a certain period of time has elapsed, the power distribution bus connection switch 14 is closed. Thereafter, the auxiliary switch 30 is opened and the power supply switching operation is completed.

As described above, in this embodiment, an accident in the power receiving system, power receiving bus system, or power distribution system is detected, and the power is switched only to the necessary system, and when switching the power, the inrush current caused by the closing of each switch is Since the current is shunted to the reactor, no inrush current is applied to the load of the motor connected to the grid. This makes it possible to reduce the generation of transient torque when the load is an electric motor.

In addition, although the above embodiment describes a power system with a two-line power receiving system, the same effects and effects can also be obtained for multiple lines with two or more lines by configuring the automatic power switching device main body 3 corresponding to each switch. is obtained.

Furthermore, the present invention is not limited to the above embodiments,
For example, the power receiving system and power distribution system reactors 27 and 29 may be replaced by resistors, and various other modifications may be made.

〔Effect of the invention〕

According to the present invention described above, the first switching circuit operates when an accident occurs in the receiving power supply system in a multi-line power receiving system, and the second switching circuit operates when an accident occurs in the receiving bus system. This switching circuit is equipped with a switching circuit and a third switching circuit that operates in the event of an accident in the power distribution system.When switching the power supply, the upper layer consists of a reactor or resistor, so that the power supply can be switched at high speed, and the power supply can be switched at high speed. It is possible to provide an automatic power supply switching device that can reduce the influence of rush current generated during bending.

[Brief explanation of drawings]

Fig. 1 is a power system diagram showing the entire power system of a two-line power receiving system to which a conventional automatic power switching device is applied, and Fig. 2 is a two-line power receiving system to which an embodiment of the automatic power switching device according to the present invention is applied. FIG. 3 is a power system diagram showing the power system of the automatic power switching device according to the present invention; FIG. 4 shows the structure of the automatic power switching device according to the present invention; FIG. It is a flowchart showing a procedure. DESCRIPTION OF SYMBOLS 1... First power receiving switch, 2... Second power receiving switch, 3... Power receiving bus connection switch, 4... First load switch, 5... Second power receiving switch. Load switch, 6... First electric motor, 7... Second electric motor, 8... First transformer, 9
...Second transformer, 10...First transformer primary switch, 11...Second transformer primary switch, 12...First transformer secondary switch , 13...Second transformer secondary switch, No.4...Distribution bus connection switch, 15...Third
Load switch, Noro... Fourth load switch, 17...
-Third electric motor, 18...Fourth electric motor, 19...
A first potential transformer, 20... a second potential transformer,
21... First undervoltage relay, 22... Second undervoltage relay, 23... Third instrument transformer, 24...
... Fourth instrument transformer, 25... Third undervoltage relay, 26... Fourth undervoltage relay, 27... Reactor, 28... Auxiliary switch, 29... Reactor, 30... Auxiliary switch, 31... Automatic power switching device main body, 32... Automatic power switching circuit in case of power receiving system fault,
33...Automatic power switching circuit for receiving tortoise bus line, 34...Automatic switching circuit for power supply in the event of a power distribution system fault, P...First receiving power supply, B2...Second receiving power supply, B1...・First power receiving bus, B2...second power receiving bus, B1...first
Distribution bus, B12...Second distribution bus, Fl...
1st power receiving system) F' l l −°゛1st power distribution system, F
Bl...First receiving bus system, R-yy...Contact of protection relay, R-Fil...Contact of protection relay, R-
FBJ...Protective relay contact. Applicant's Representative Patent Attorney Takehiko E No. 1 Figure 2 Figure 3 Figure 31 Figure 4 Figure 5

Claims (1)

[Claims] First and second power receiving power sources, first and second power receiving switches connected to corresponding ones of the first and second power receiving power sources, and corresponding to the power receiving switches. a normally closed power receiving bus connection switch that connects the first and second power receiving buses, and first and second power receiving buses that correspond to the first and second power receiving buses; A multi-line power reception system comprising first and second distribution buses connected via a distribution system, and a normally open distribution bus connection main switch that connects the first and second distribution buses. In an automatic power switching device applied to a power grid, a series circuit including a normally open auxiliary switch and an impedance element connected in parallel to a power receiving switch corresponding to the second power receiving power source, and a series circuit including an impedance element connected to the power receiving switch corresponding to the second power receiving power source, a series circuit including a normally open auxiliary switch and an impedance element connected in parallel; a power receiving system fault detection relay that detects a fault on the first power receiving power source side and opens the corresponding first power receiving switch; The first power receiving switch detects a fault in the first power receiving bus system. a power receiving bus connecting main switch, a power distribution system fault detection relay that opens the switches provided in the first power distribution system, and the second power receiving power source energized by the operation signal of the power receiving system fault detection relay. an automatic power supply switching circuit in the event of a power receiving system fault that sequentially closes the auxiliary switch and the second power receiving switch provided on the side; and the second power receiving power source is energized by the operation signal of the power receiving bus fault detection relay. an automatic power switching circuit in the event of a power receiving bus system fault, which sequentially closes an auxiliary switch and a second power receiving switch provided on the side, and sequentially closes the power distribution bus contact auxiliary switch and the power distribution bus contact main switch; An automatic power supply switching device comprising: an automatic power supply switching circuit in the event of a distribution system fault, which is energized by an operation signal of a system fault detection relay and sequentially closes the distribution busbar communication auxiliary switch and the distribution busbar communication main switch.