JP2561133Y2 - Switch - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch used for switching the power supply of a construction bank for uninterruptible low-voltage distribution line construction.

[0002]

2. Description of the Related Art Conventionally, in the construction of low-voltage distribution lines such as the replacement of pole transformers, uninterruptible low-voltage distribution lines using instantaneous switching switches have been implemented in order to prevent blackouts of the low-voltage distribution lines in the construction bank. You. Next, the instantaneous switching switch will be described. This switch has a main circuit section 1 shown in FIG. 3, and this main circuit section 1 has input terminals 2u, 2v, 2 of U, V, and W phases.
A circuit breaker 4 for short-circuit overcurrent interruption and a switching unit 5 are provided in series between w and the output terminals 3u, 3v, 3w, respectively.

The switching section 5 for each phase is formed by arranging a series circuit of a fuse 7 for overcurrent protection and a triac 8 for energizing at the time of switching transient at a contact 6 of an electromagnetic contactor for steady current conduction. You. Reference numeral 9 denotes an auxiliary contact provided for only the U-phase contact 6 for informing the open / close state.

The detection control unit (not shown) performs the following power detection, phase detection, manual input, manual release, standby state control, automatic input, reverse charging prevention operation, and the like.

[0005] The normality or abnormality of the input / output voltage of each phase is determined based on the voltage between the U phase on the input side and the ground. If the output phase rotation direction is the same as the input phase rotation direction, it is determined to be normal. Manual closing If the results of power detection and phase detection are not abnormal, the contact 6 is closed and turned on by operating the "ON" button.

Manual release The contact 6 is unconditionally released by operating the "OFF" button. Standby state control (automatic closing) If the results of the power detection and phase detection are not abnormal, the standby state is set by pressing the "standby" button. The triac 8 is turned on, the contact 6 is closed, and the triac 8 is automatically turned on. Input-side no-voltage operation When the input-side voltage becomes zero during energization, the drive power supply of the switch is stopped and the electromagnetic contactor is released naturally (100 to 200 m).
The contact 6 is automatically opened in (sec).

Next, the uninterruptible low-voltage distribution line construction will be described with reference to FIGS. 4A and 4B showing connection states before and after switching of the power supply of the construction bank. In this construction, a construction switch 10, comprising the above-mentioned instantaneous switching switch,
A switching switch 11 is used.

Further, in FIGS. 4A and 4B,
A is a construction bank, B is another bank, 12a and 12b are low-voltage distribution lines of banks A and B, and 13a and 13b are banks A and
B, a transformer such as a pole transformer, and 14a and 14b are transformers 1
Connection lines (secondary supplementary lines) between the secondary sides of 3a and 13b and distribution lines 12a and 12b, and 15a and 15b are high-voltage main lines 1
6 is a fuse between the primary side of the transformers 13a and 13b. Then, for example, when replacing the transformer 13a, first, a switching operation is performed.

In this operation, first, the connection line 14a
A switch 10 is attached in parallel to the
Numeral 0 indicates that the input side of the main circuit unit 1 is connected to the secondary side of the transformer 13a, and the output side is connected to the distribution line 12a. Next, the switch 10 is manually turned on and closed, and after the switch is closed, the connection line 14a is cut off as shown by the mark x in FIG. 4A, and after this cut-off, the switch 11 connects the low-voltage bypass cable. And attached between the distribution lines 12a and 12b.

At this time, the switch 11 has its input side connected to the distribution line 12b and its output side connected to the distribution line 12b.
The bank A is supplied with power from the substation on the bank A side, and the bank B is supplied with power from the substation on the bank B side.

Further, after the switch 11 is set to the closing standby state, the switch 10 is manually opened. At this time, the switch 11 is automatically closed instantaneously due to the loss of voltage on the output side.
The power supply line of the distribution line 12a is connected from the transformer 13a to the transformer 13
b, the power supply of the bank A is switched, and the state shifts to the connection state of FIG. And the fuse 15a
Is opened and both the primary side and the secondary side of the transformer 13a are cut and opened, and then the transformer 13a is replaced.

When the replacement is completed, the operation shifts to the switching back operation. First, the input side of the switch 10 is connected to the secondary side of the replaced transformer 13a by a cable, and FIG.
After that, the fuse 15a is turned on, the switch 10 is set to the closing standby state, and the switch 11 is manually opened.

At this time, the switch 10 is automatically turned on instantaneously due to the disappearance of the voltage on the output side.
The power supply line a is switched from the transformer 13b to the transformer 13a, and the power supply of the bank A is switched back. Further, the transformer 13
The secondary side of a and the distribution line 12a are connected by a new connection line 14a, and after this connection, the switch 10 is manually opened.
Then, the construction equipment such as the switches 10, 11 and the cables are removed, and the construction is completed.

[0014]

In the case of the conventional uninterruptible low-voltage distribution line construction, the switches 10 and 11 that are turned on are kept closed until the contacts 6 are opened by manual or reverse charging prevention operation. In particular, there is a problem that an electric shock accident or the like due to the closing of the switch 10 occurs during the switching work.

That is, during the switching operation, the connection line 14a
The switch 10 attached in parallel to the connection line is turned on, and the connection line 1
If the switch 11 is set to the closing standby state after the disconnection of the switch 4a, thereafter, the switch 1 is opened due to, for example, an accident at the substation on the bank A side until the switch 10 is opened.
When the power supply to the distribution line 12a via the power line 0 is interrupted, the switch 11 is automatically turned on instantaneously due to the disappearance of the voltage on the output side.

By this automatic turning on, the switch 10 is energized and the power is supplied to the substation on the bank B side via the switch 11 within a time sufficiently shorter than the spontaneous release time of the electromagnetic contactor, so that the power is continuously supplied and the reverse charging is performed. The preventive action does not work and the closed state is maintained. Then, since both the switches 10 and 11 are closed, the power supply of the substation on the bank B side reverse charges the primary side through the secondary side of the transformer 13a, and an electric shock accident or the like occurs. It is dangerous. An object of the present invention is to prevent an electric shock accident or the like caused by the reverse charging.

[0017]

In order to achieve the above object, in the switch of the present invention, a power failure detection unit for monitoring a power failure on a secondary side of a transformer applied to an input side of a main circuit unit. And an open command gate unit for generating a forced open command by simultaneously inputting a closed state signal of the main circuit unit and a power failure detection signal of the power failure detection unit, and an opening for forcibly opening the main circuit unit by the forced open command. A control unit.

[0018]

In the case of the switch of the present invention configured as described above, it is used as a switch for construction of uninterruptible low-voltage distribution line construction, and is connected to a secondary side of a transformer such as a pole transformer of a construction bank. After being installed in parallel with the connection line to the low-voltage distribution line and inserted, and before being manually opened and the power is switched, a power failure occurs on the high-voltage main line on the primary side of the transformer, and the low-voltage distribution line When reverse charging from the output side connected to the electric wire occurs, immediately before the reverse charging, a power failure detection signal of the power failure detection unit and a closed state signal of the main circuit unit are simultaneously generated.

Then, both signals are simultaneously input to the opening command gate section to generate a forced opening command, and the opening control section forcibly opens the main circuit section based on this command. for that reason,
Reverse charging is prevented, thereby preventing an electric shock accident or the like.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment will be described with reference to FIGS. FIG. 1 shows the construction of a construction switch 10, in which the same reference numerals as those in FIGS. 3 and 4 denote the same or corresponding components.
In that a forcible opening 18 for preventing reverse charging is added to
The opening unit 18 includes a power failure detection unit 19, a delay unit 20, an opening command gate unit 21, and an opening control unit 22.

The power failure detection section 19 is formed by power failure detection circuits 19u, 19v, and 19w for each phase.
0 is formed by delay circuits 20u, 20v, 20w for each phase, the gate unit 21 is formed by AND gates 21a, 21b, and the control unit 22 is a drive amplifier 22a for the electromagnetic contactor relay 23 and an inverting amplifier 22b for driving the thyristor.
Formed by Furthermore, the power failure detection circuit 19u of each phase
To 19w and the delay circuits 20u to 20w are formed identically, and the configuration is shown in FIG. 2, for example.

FIG. 2 shows a U-phase power failure detection circuit 19u and a delay circuit 20u.
4, a reference voltage generator 25 and a comparator 26, and a delay circuit 20u is provided with a monostable multivibrator 27 having a time constant resistor R and an external capacitor C, and a NOR gate 2
Consists of eight. Note that + B in FIGS. 1 and 2 indicates a DC positive power supply terminal.

The power failure detection circuits 19u-19 for each phase
w is the absolute value conversion circuit 24 for each phase voltage of the input terminals 2u to 2w.
, Is converted to an absolute value and monitored. The absolute value is compared with a reference voltage of the generator 25 by a comparator 26. When each phase voltage is lost due to a power failure or the like, the comparator 26 The output signal is inverted to a power failure detection signal of “0”.

Further, the output signals of the respective power failure detection circuits 19u to 19w are supplied to the monostable multivibrators 27 and NOR gates 28 of the delay circuits 20u to 20w, and are delayed by the multivibrator 27 for a predetermined time determined by the resistor R and the capacitor C. . This delay time is used to determine whether or not all phase voltages have disappeared due to a power failure and to prevent malfunction.
The time required for automatic loading when 0 and 11 are set to the loading standby state is set to about 8 msec, which is shorter than 10 msec.

When a predetermined delay time elapses after the power failure detection signals are output from the power failure detection circuits 19u to 19w, the output signals of the delay circuits 20u to 20w are inverted to "1". Output signal
Invert to 1 ".

Further, the output signal of the AND gate 21a and the contact signal of the auxiliary contact 9 of the main circuit section 1 are output from the AND gate 2a.
1b, the output signal of the AND gate 21a becomes "1" due to a power failure, and the main circuit section 1 is closed, and the contact signal of the auxiliary contact 9 becomes a closed signal of "1". Only, the forcible release command of “1” is output from the AND gate 21b to the control unit 22. Then, the drive transistor at the output stage of the amplifier 22a is turned off by this opening command,
The power supply drive of the relay 23 is forcibly stopped, and the contact 6 of the opening / closing unit 5 of each phase is opened.

Further, the output of the inverting amplifier 22b becomes "0" by the forced open command of "1" of the AND gate 21b, and the driving of the triac 8 of the opening / closing section 5 of each phase is prohibited. Then, when all the phase voltages on the input side are lost due to a power failure even instantaneously, the power supply to the relay 23 is stopped, the triac 8 is kept off, and the switch 10 is forcibly opened.

For this reason, in the switching work of the low-voltage distribution line work shown in FIGS. 4A and 4B, the switch 10 is mounted in parallel with the connection line 14a and is manually turned on.
a is cut off, and the switch 11 is attached between the distribution lines 12a and 12b to be set in an input standby state.
If the substation on the bank A side loses power and the all-phase voltage on the input side of the switch 10 disappears before the switch is manually opened, the switch 10 is forcibly turned off immediately before the switch 11 is automatically turned on. Be released.

Therefore, even if the switch 11 is automatically turned on, the primary side and the secondary side of the transformer 13a are not reversely charged by the power supply on the bank B side via the switch 11, thereby preventing an electric shock accident or the like. And safety is improved.

[0030]

The present invention is configured as described above and has the following effects. At the time of uninterruptible low-voltage distribution line construction, a connection line 14 between the secondary side of a transformer 13a such as a pole transformer of the construction bank A and the low-voltage distribution line 12a.
a, a power failure occurred on the high voltage main line 16 on the primary side of the transformer 13a, and the power supply was connected to the low voltage distribution line 12a before being manually opened and the power was switched. Even if reverse charging from the output side occurs, immediately before this reverse charging, a power failure detection signal of the power failure detecting unit 19 and a closed state signal of the main circuit unit 1 are simultaneously generated, and both signals are released. Simultaneously, a forced open command is generated, and the open control unit 22 forcibly opens the main circuit unit 1 based on this command, thereby preventing reverse charging, preventing electric shock accidents and the like, and improving safety. And so on.

[Brief description of the drawings]

FIG. 1 is a connection diagram of an embodiment of the switch of the present invention.

FIG. 2 is a detailed connection diagram of a part of FIG. 1;

FIG. 3 is a connection diagram of a main circuit portion of the instantaneous switching switch.

4 (a) and 4 (b) are connection diagrams before and after switching of a power supply in uninterruptible low-voltage distribution line construction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main circuit part 10 Construction switch 12a, 12b Low-voltage distribution line 13a, 13b Pole transformer 14a, 14b Connection line 16 High-voltage main line 18 Forcible opening part 19 Power failure detection part 21 Opening command gate part 22 Opening control part A Construction bank

Claims (1)

(57) [Scope of request for utility model registration] At the time of uninterruptible low-voltage distribution line construction, the main circuit part is mounted in parallel with the connection line between the secondary side of a transformer such as a pole transformer of a construction bank and the low-voltage distribution line, and put in. And a switch in which the main circuit is opened when the power supply is switched after the connection line is disconnected, wherein a power outage for monitoring disappearance of a secondary voltage of the transformer applied to an input side of the main circuit is performed. A detection unit, an open command gate unit that generates a forced open command by simultaneous input of a closed state signal of the main circuit unit and a disappearance detection signal of the power failure detection unit, and the main circuit unit by the forced open command. A switch having an opening control unit for forcibly opening the switch.