JP2003235160A - System switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system switching device which has flexibility in designing the devices without degrading the switching performance. <P>SOLUTION: A series circuit of thyristor switches and reactors is connected in parallel with a change-over switch which mechanically switches power supply systems to a load. When the power supply systems are manually switched, a switching command is issued to the change-over switch. At the same time, an on-command is issued to the thyristor switch connected with the power supply system to which connection is to be switched. Consequently, switching is carried out without instantaneous interruption of the output. In automatic switching, which takes place if any trouble occurs in the power supply system supplying power and an undervoltage detection signal is outputted, a switching command is issued only to the change-over switch first. After the change-over switch is disconnected from the faulty system and zero voltage is detected at the output end of the device, or after instantaneous power interruption for such a time that the load is not influenced, an on-command is issued to the thyristor switch in the power supply system to which connection is to be switched. Thereby, switching is carried out with instantaneous interruption of output. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system switching device for switching between two system power sources, and more particularly to a circuit type system switching device that does not restrict the system power source and load.

[0002]

2. Description of the Related Art A conventional system switching device is provided with a mechanical switch for bidirectionally switching each power source between a load and a series circuit of a thyristor switch and a reactor connected between the switch and the load. With the circuit configuration, there is no distinction between manual switching and automatic switching, or a method that achieves output uninterruptible performance by performing lap switching between power supplies at the time of switching, or a circuit is configured with only thyristor switches and lap switching is not performed. In addition, the system was designed to switch the output instantaneously so that the load is not affected.

FIG. 11 is a main circuit connection diagram showing an example of the conventional system switching device described above. In the figure, two system input power sources 1A and 1B are connected to both fixed contacts of the mechanical switching switch 2, and an output end 10 derived from the movable contact is connected to a load 5. A semiconductor switching shunt composed of a series circuit of a thyristor switch 3A and a reactor 4A is connected in parallel between the A-side fixed contact of the switching switch 2 and the output terminal 10, and similarly, the B-side fixing of the switching switch 2 is fixed. A semiconductor switching shunt consisting of a series circuit of a thyristor switch 3B and a reactor 4B is connected in parallel between the contact and the output terminal 10. The switching switch 2 is switched to the A-side fixed contact by the switching command, and switched to the B-side fixed contact by the switching command. The thyristor switch 3A is ON-controlled by an ON command, and the thyristor switch 3B is ON-controlled by an ON command.

In the main circuit of FIG. 11, input power supplies A,
Undervoltage detection circuit 27 for detecting an undervoltage such as B power failure
A and 27B are provided, and a synchronization detection circuit 25 for detecting the synchronized state of the voltages between the two systems, that is, the frequency, the voltage, and the phase being in agreement is provided.

FIG. 12 shows an example of the structure of a logic gate circuit 14 for generating a switching command and an ON command. The logic gate circuit 14 includes AND gates 141 to 144, OR gates 145, 146, and A gates.
The ND gates 147 and 148 are provided. The logic gate circuit 14 is provided with a manual changeover switch 151 for manual changeover, and by changing this to the A side, a changeover command is given to the changeover switch 2 and an on command is given to the thyristor switch 3A. By switching to the side, a switching command is given to the switching switch 2 and an ON command is given to the thyristor switch 3B.

The AND gate 141 has a manual changeover switch 151 to an A side changeover command 151A and a synchronization detection circuit 25.
And the inverted signal of the undervoltage detection signal of the undervoltage detection circuit 27A are input. The AND gate 142 receives the undervoltage detection signal of the undervoltage detection circuit 27A and the inverted signal of the undervoltage detection signal of the undervoltage detection circuit 27B. The AND gate 143 has
The B-side switching command 151B, the synchronization detection signal from the synchronization detection circuit 25, and the inverted signal of the undervoltage detection signal of the undervoltage detection circuit 27B are input from the manual switch 151. The AND gate 144 has an undervoltage detection circuit 27B.
Of the undervoltage detection signal and the inverted signal of the undervoltage detection signal of the undervoltage detection circuit 27A are input. The output signal of the AND gate 141 and A
The output signal of the ND gate 144 is input. The output signal of the AND gate 142 and A
The output signal of the ND gate 143 is input. The output signal of the OR gate 145 and O
An inverted signal of the output signal of the R gate 146 is input. Finally, the output signal of the OR gate 146 and the inverted signal of the output signal of the OR gate 145 are input to the AND gate 148.

Normally, power is supplied to the load 5 from one of the system input power sources 1A and 1B according to the switching position of the mechanical switching switch 2. When manually switching the system input power,
For example, with both system input power supplies operating normally, the system input power supply 1
When switching from A to the system input power supply 1B, the manual selector switch 151 is switched from the A side to the B side. When the manual selector switch 151 is on the A side, the AND gate 1
A switching command is given to the switching switch 2 via 41, the OR gate 145, and the AND gate 147, and an ON command is given to the thyristor switch 3A. At this time, the AND gate 148 is inoperative and B
Side switching command and ON command are not output.
When the manual selector switch 151 is switched to the B side, the AND gate 141 turns off the output and the AND gate 143 turns on. As a result, the OR gate 146
The output of the AND gate 148 is turned on and the output of the AND gate 147 is turned off via the, so that a switching command to the switching switch 2 to the B side and an ON command to the thyristor switch 3B are given.

As is well known, the mechanical switching switch 2 requires a predetermined switching time for the switching operation in which the movable contact switches from the A side fixed contact to the B side fixed contact, so that the movable contact is A.
During the so-called contact opening time from the time when the side fixed contact is separated to the time when the B side fixed contact is contacted, switching is performed while wrapping with the B side thyristor switch 3B and switching while supplying power. . This lap switching realizes output instantaneous interruption switching, that is, switching without power failure at all.
When the movable contact of the switching switch 2 contacts the B side fixed contact,
Power is again supplied from the switching switch 2, and the switching operation is completed. When the movable contact of the switching switch 2 is in contact with the B-side fixed contact, the load current flows through the switching switch 2 and hardly flows into the series circuit of the thyristor switch 3B and the reactor 4B.

Also in the case of the switching operation from the system input power source 1B to 1A, the mechanical switching switch 2 is instructed to switch to the A side and the A side thyristor switch 3 is used in the same manner as described above.
A Heon command is given. By thus turning on the thyristor switch 3A, non-instantaneous interruption switching is realized.

In the case of automatic switching, the undervoltage detection circuit 27
The switching operation is started by detecting the undervoltage of A or 27B. For example, in the case of automatically switching to the B system input power supply 1B due to the power failure of the A system input power supply 1A, first, the undervoltage detection circuit 27A operates to generate the undervoltage detection signal, and the AND gate 142 outputs the output. Thus, a switching command is issued to the switching switch 2 via the OR gate 146 and the AND gate 148, and an ON command is given to the thyristor switch 3B. As a result, switching to the B-system input power supply 1B can be performed as in the case of manual operation. At this time, on the A side, the output of both AND gates 141 and 144 is off, so both the switching command and the on command are off.

In FIG. 13, the mechanical switch 2 and the reactors 4A and 4B are omitted from the circuit of FIG. 11, and the system input power is switched only by switching the thyristor switches 3A and 3B. In the case of system switching, an off command is first given to the thyristor switch on the power feeding system side, and an on command is given to the thyristor switch on the switching destination system side after a short power failure time (temporary interruption time). That is, in this method, switching is performed by eliminating the lap time that causes a cross current between the systems and providing an output instantaneous interruption time of about several ms that does not significantly affect the load 5. Needless to say, this circuit is a system in which a load current is always passed through the thyristor switch 3A or 3B.

[0012]

As shown in FIGS. 11 and 12, in the system in which the switching switch 2 and the thyristor switches 3A and 3B are used to perform the lap switching, the voltage difference or the phase difference between the two systems is caused during the lap period. A cross current flows between both systems. Therefore, in addition to the condition that there is no voltage difference and phase difference, the thyristor switch 3
Reactors 4A and 4B are connected in series with A and 3B to suppress a cross current flowing between both systems.

As shown in FIG. 13, the thyristor switch 3
Since the system switching device constituted only by A and 3B continuously applies the load current to the thyristor switch, the output voltage drop due to the ON voltage of the thyristor element and the heat loss corresponding to the product of the ON voltage and the load current are generated. . Therefore, a cooling device for forced cooling is required.

When the switch and the thyristor switch are used in combination as shown in FIG. 11, almost no heat loss is generated in the thyristor switch, and no cooling device is required. The switching causes a restriction in applying the device. Especially, in the automatic switching that switches to the normal system when the power supply system is abnormal, when a load is connected to the upper power system, the load current of the system switching device and the power supply to the upper system load due to wrapping are superimposed. Depending on the capacity of the load connected to the grid, there is a possibility that the load will be stopped due to a drop in the output voltage or a shunt trip of the upper breaker. Although cross-flow can be suppressed to some extent by selecting the reactor value, there is little freedom in designing the device when applied to any system.

An object of the present invention is to provide a system switching device having a large degree of freedom in device design without deteriorating the switching performance.

[0016]

In order to achieve the above object, the invention according to claim 1 is a system switching device for switching a power supply system to a load from one of two power systems to the other. A switching switch that is connected between the power supply system and the load switching system to mechanically switch the power supply system to the load, and consists of a series circuit of thyristor switches and reactors. , The semiconductor switching shunt connected in parallel between the two power supply systems, and when performing manual switching between both power supply systems, the switching command to the switching switch and the thyristor switch connected to the system power supply side of the switching destination In the case of automatic switching that is performed when an ON command is given to switch the output without instantaneous interruption, and when an undervoltage detection signal is output due to an abnormality in the power supply system that is supplying power, first, only the switching switch is used. Switching To the thyristor switch on the power supply side of the switching destination after the main contact of the switching switch is disconnected from the abnormal system side and zero voltage is detected at the device output end or after a momentary disconnection time during which there is no effect on the load. And a logic gate circuit for giving an ON command and switching the output instantaneously. According to the present invention, it is possible to eliminate restrictions on application of the automatic switching device in automatic switching.

According to a second aspect of the present invention, in a system switching device for switching the power supply system to the load from one of the two power supply systems to the other, the power supply system to the load is connected between the load and the power supply system. And a semiconductor switching shunt connected in parallel between each system side main contact of the switching switch and a common movable main contact, each consisting of a series switch of a thyristor switch and a reactor. When performing manual switching between both power supply systems, the ON command is simultaneously given to the switching command to the switching switch and the thyristor switch connected to the system power supply side of the switching destination, and the output is instantaneously switched without interruption. In the case of automatic switching that is carried out when an abnormality occurs in the power supply system during power supply and the power supply current becomes zero, first the switching command is given only to the switching switch by detecting zero power supply current on the abnormal system side, An ON command is given to the thyristor switch on the power supply side of the switching destination after the main contact of the switch has been disconnected from the abnormal system side and zero voltage has been detected at the device output end, or after a momentary interruption time during which the load is not affected. , And a logic gate circuit for performing output instantaneous interruption switching.

According to a third aspect of the present invention, in a system switching device for switching the power supply system to the load from one of the two power supply systems to the other, the power supply system to the load is connected between the load and the power supply system. Between the switching switch that mechanically switches the switch and the diode bridge whose AC ends are connected in parallel between each system side main contact of the switch and the common movable main contact, and between each DC end of the diode bridge. When performing a manual switching between the power supply system and the semiconductor switching shunt consisting of the self-extinguishing element connected to the, the switching command to the switching switch and the self-extinguishing connected to the system power source side of the switching destination. In the case of automatic switching that is performed when an ON command is simultaneously given to the element and output instantaneous switching is performed and an abnormality occurs in the power supply system that is supplying power and an undervoltage detection signal is output,
Firstly, the switching command is given only to the switching switch, and the main contact of the switching switch is switched from the power feeding system side to the other system side. And a logic gate circuit for switching with a switch. According to the present invention, it is possible to control the lap time at the time of switching to an extremely short time, and it is possible to eliminate a reactor for suppressing cross current.

According to a fourth aspect of the invention, in a system switching device for switching the power supply system to the load from one of the two power supply systems to the other, the power supply system to the load is connected between the load and the power supply system. Between the switching switch that mechanically switches the switch and the diode bridge whose AC ends are connected in parallel between each system side main contact of the switch and the common movable main contact, and between each DC end of the diode bridge. When performing a manual switching between the power supply system and the semiconductor switching shunt consisting of the self-extinguishing element connected to the, the switching command to the switching switch and the self-extinguishing connected to the system power source side of the switching destination. In the case of automatic switching, which is performed when the ON command is simultaneously given to the element and the output is switched without instantaneous interruption, and the power supply current during power supply becomes abnormal and the power supply current becomes zero, the power supply on the abnormal system side Zero current The detection command first gives a switching command only to the switching switch, and the main contact of the switching switch switches from the power feeding system side to the other system side. And a logic gate circuit for switching the switching switch.

The invention according to claim 5 is the invention according to claim 2 or 4.
In the system switching device described in (1), a load current detection circuit for detecting an overcurrent of the load is provided, and the logic gate circuit detects an overcurrent during the power supply lap period from both power supply systems during manual switching or automatic switching. It is characterized in that it includes means for suppressing the wrap current by controlling the voltage of the self-extinguishing element when detected by the circuit.

According to a sixth aspect of the present invention, in the system switching device according to the fifth aspect, the logic gate circuit performs non-instantaneous switching by lap switching between systems during manual switching, and self-erasing in the case of automatic switching. It is characterized by performing instantaneous interruption switching by gate control of the arc element.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION <First Embodiment> An embodiment of the present invention will be described below with reference to FIGS. 1 and 2
In FIG. 11, parts that are the same as or correspond to those in FIGS. 11 and 12 are given the same reference numerals, and description thereof is omitted.

The main circuit configuration of FIG. 1 is the same as that of FIG. However, here, an undervoltage detection circuit (0 V for detecting an undervoltage of the output terminal 11 via the instrument transformer 12 is used.
-DET) 13 is provided, and the undervoltage detection circuit 13 outputs a zero voltage detection signal D0 when the output end voltage becomes zero.

The logic gate circuit 14 shown in FIG.
In comparison with that of the latter AND gate 147,
148 is removed, and AND gates 149 and 150 are newly added.
OR gates 151 and 152, and AND gate 153
Corresponds to the addition of ˜156. AND gate 14
9 receives the output signal of the AND gate 142 and the zero voltage detection signal D0, and the AND gate 150 receives the output signal of the AND gate 144 and the zero voltage detection signal D0. The OR gate 151 is an AND gate 141,
The output signal of 150 is input, and the OR gate 152 outputs AN
The output signals of the D gates 143 and 149 are input. AN
The D gate 153 is a gate for outputting a switching signal for switching the switching switch 2 to the A system side.
The output signal of the R gate 145 and the inverted signal of the output signal of the OR gate 146 are input. AND gate 154
Is a gate for outputting a switching signal for switching the switching switch 2 to the B system side, and is an OR gate 146.
Input signal and an inverted signal of the output signal of the OR gate 145 are input. The AND gate 155 is a gate for outputting an ON command to the thyristor switch 3A, and includes the output signal of the OR gate 151 and the OR gate 1.
The inverted signal of the output signal of 52 is input. The AND gate 156 is a gate for outputting an ON command to the thyristor switch 3B, and receives the output signal of the OR gate 152 and the inverted signal of the output signal of the OR gate 151 as inputs.

The operation of the system switching device shown in FIGS. 1 and 2 will be described. First, a case will be described in which, for example, the A-system input power supply 1A is switched to the B-system input power supply 1B by manual switching. First, the manual selector switch 151 is switched to the B side. As a result, the AND gate 153 outputs "0", the synchronization detection circuit 25 detects the synchronization state (the synchronization detection signal 25 is "1"), and an undervoltage occurs on the B system input power supply 1B side. Is not done (undervoltage detection circuit 27B is "0" output),
The AND gate 143 outputs “1”, the switching command is first output from the AND gate 154 via the OR gate 146, and at the same time, the on command of the thyristor switch 3A is turned off and the thyristor switch 3B is turned on by the on command. . By doing so, during the switching period of the switching switch 2 as described above, the non-instantaneous switching can be performed by the lap switching with the thyristor switch 3B. After the switching of the switching switch 2 is completed, the switching switch 2 short-circuits the thyristor switch 3B and the reactor 4B, and the load current flows through the switching switch 2 and almost flows into the series circuit composed of the thyristor switch 3B and the reactor 4B. Disappear.

Next, when an abnormality occurs in the power supply system and automatic switching to the normal system is performed, for example, the A system input power source 1A
A case will be described in which an abnormality occurs in the power supply and the system is switched to the normal B-system input power supply 1B. In this case, as shown in FIG. 3, first, the undervoltage detection circuit 27A of the A system outputs the undervoltage detection signal D0, whereby the switching command and the ON command are turned off, and the AND gates 142, O
A switching command is issued via R gate 146 and AND gate 154. In response to the switching command, the switching switch 2 starts the switching operation to the B system input power supply 1B side, but the switching is not performed immediately. Initially, although it is incomplete from the A system input power supply 1A in the form of arc discharge, the load Continue to apply current. When the opening operation on the A side proceeds and the undervoltage detection circuit 13 outputs the zero voltage detection signal D0 at a certain stage, A
The ND gate 149 issues an operation output, and there is OR
The AND gate 156 operates via the gate 152 and sends an ON command to the thyristor switch 3B. As a result, the load current is supplied from the B-system input power supply 1B via the thyristor switch 3B and the reactor 4B. The switching process progresses further, and B of the switching switch 2
When the switching operation to the system side is completed, the load current flows through the switching switch 2 and hardly flows into the series circuit including the thyristor switch 3B and the reactor 4B. At this time, the circuits of the thyristor switch 3B and the reactor 4B are short-circuited by the switching switch 2 and the load current hardly flows. As described above, the switching between the system input power supplies can be performed without setting the wrap period between the system input power supplies. In this embodiment, the time for delaying the transmission of the ON command of the thyristor switch depends on the output terminal 1.
It depends on the voltage detection of 0 and not on the mechanical properties of the switchgear 2. Therefore, a system switching device applicable to any system can be configured by selecting a switching system of manual switching or automatic switching.

<Second Embodiment> A second embodiment will be described with reference to FIGS. Current detectors 17A and 17B are respectively arranged in the current circuits of the system input power supplies 1A and 1B in the main circuit of FIG. 4, and the supply current (IA) of each system input power supply is passed through the current detectors 18A and 18B, respectively. ), (IB) are detected. This detected current is
It is used instead of the undervoltage detection signal D0 in FIGS. That is, the output of the AND gate 142 and the detection current (IA) on the A system side are input to the AND gate 149, and AN
The output of the AND gate 144 and B
Input the detection current (IB) on the system side. Each of the current detection circuits 18A and 18B detects that the current has become zero or almost zero, and outputs an operation output "1".

This embodiment corresponds to a condition in which the zero voltage detection condition by the undervoltage detection circuit 13 of the output terminal 10 in the first embodiment is replaced by the zero current detection of the other side system. For example, when automatic switching from the A system side to the B system side is performed, the generation condition of the zero voltage detection signal D0 in the first embodiment is here the generation of the zero current detection signal of the A system side. It will be. Others are substantially the same as those in the first embodiment.

<Third Embodiment> FIGS. 6 to 8 show a third embodiment. In the main circuit shown in FIG.
The reactors 4A and 4B in FIG. 1 are removed, and instead of the thyristor switches 3A and 3B, diode bridge circuits 21A and 21B, and self-extinguishing elements 22A and 22B connected between their DC terminals, for example, IGBT (insulated gate bipolar). A semiconductor switching shunt composed of a transistor). As is well known, the self-extinguishing element can control the on / off operation by a gate command,
By using this, it becomes possible to freely adjust the lap time for switching. Mechanical switching switch 2 described above
Self-extinguishing element 22 according to the switching time due to the characteristics of
By the ON / OFF command to A and 22B at proper timing, the switching operation can be performed in the shortest lap time.

The logic gate circuit 14 shown in FIG. 7 has OR gates 151 and 152 and an AND gate 1 for generating the latter ON command in comparison with that of FIG.
55 and 156 are omitted and replaced with the self-extinguishing element 22.
This corresponds to the one in which a gate voltage control circuit 158 for sending an ON / OFF command to A and 22B is provided.
In the logic gate circuit 14, the gate voltage control circuit 15
8, AND gates 149 and 150 and OR gate 1
The output signals of 45 and 146 are introduced, and the self-extinguishing element 22 is generated at the timing of generation / disappearance of the above-mentioned ON command.
An on / off command is sent to A and 22B.

In this embodiment, power is supplied only from the switching switch 2 at all times, the on / off command is in the off state, and the self-extinguishing elements 22A and 22B are in the off state. Manual switching, for example, when switching from the A system to the B system, starting from switching the changeover switch 151 to the B system side is the same as that already described with reference to FIG. 1 and FIG. The AND gate 143 is operated on the condition that the synchronization of the circuit 25 is detected and the undervoltage detection circuit 27B is not operated, and the operation output of the AND gate 154 gives a switching command from the AND gate 154 to the switching switch 2 first. give. At the same time, the on / off command is turned off via the gate voltage control circuit 158 to turn off the self-extinguishing element 22A, and the on / off command is turned on to turn on the self-extinguishing element 22B. After that, the mechanical switching switch 2 completes the switching to the B-side input power supply system 1B side, and the switching operation ends. After the switching operation of the switching switch 2 is completed, the on / off command is turned off at an appropriate time.

Next, according to the above, the case where the A system is switched to the B system by the voltage drop of the A system will be described. In this case, as shown in FIG. 8, the undervoltage detection circuit 27A on the A system side outputs the zero voltage detection signal D0, whereby the AND gate 142 issues an operation output, which causes the gate voltage control circuit 158 to output. First, the on / off command is turned on, the self-extinguishing element 22B is turned on, and power is supplied from the B-system input power supply 1B. At this point of time, the A-side self-extinguishing element 22A is still on,
Lap switching is performed by the self-extinguishing elements 22A and 22B of both systems. After an extremely short lap time internally set in advance, the on / off command for the A-side self-extinguishing element 22A is turned off and the A-side self-extinguishing element 22A is turned off. After this,
The movable main contact of the switching switch 2 comes into contact with the B system side, and then the ON / OFF command is turned off at an appropriate time to complete the series of switching processes. In the switching process of this embodiment, the gate control of the self-extinguishing elements 22A and 22B is a lap switching in which the power supply from both systems wraps for an extremely short time during the switching, and the reactor for cross current suppression is not required. be able to.

[0033]

As described above, according to the present invention, in order to minimize the power generation loss and the voltage drop by using the mechanical switching switch and to improve the switching performance, the manual switching and the automatic switching are performed. By changing the switching method depending on the case of switching, it is possible to provide a system switching device with a high degree of freedom in system design.

Further, it is possible to provide a system switching device which realizes non-instantaneous switching by only the semiconductor switching element.

[Brief description of drawings]

FIG. 1 is a main circuit connection diagram showing a first embodiment of a system switching device according to the present invention.

FIG. 2 is a connection diagram showing a configuration example of a logic gate circuit that implements switching control of the device of FIG.

FIG. 3 is a time chart during an automatic switching operation in the apparatus shown in FIGS.

FIG. 4 is a main circuit connection diagram showing a second embodiment of the system switching device according to the present invention.

5 is a connection diagram showing a configuration example of a logic gate circuit for switching control of the device of FIG.

FIG. 6 is a main circuit connection diagram showing a third embodiment of the system switching device according to the present invention.

7 is a connection diagram showing a configuration example of a logic gate circuit for switching control of the device of FIG.

FIG. 8 is a time chart at the time of automatic switching operation in the apparatus of FIGS.

FIG. 9 is a main circuit connection diagram showing a fourth embodiment of the system switching device according to the present invention.

FIG. 10 is a main circuit connection diagram showing a fifth embodiment of the system switching device according to the present invention.

FIG. 11 is a main circuit connection diagram showing an example of a conventional system switching device.

12 is a connection diagram showing a configuration example of a logic gate circuit for switching control of the device of FIG.

FIG. 13 is a main circuit connection diagram showing another configuration example of the conventional system switching device.

[Explanation of symbols]

1A A system input power supply 1B B system input power supply 2 switch 3A A system thyristor switch 3B B system thyristor switch 4A, 4B reactor 5 load 13 Undervoltage detection circuit 14 Logic gate circuit 18A, 18B current detection circuit 21A, 21B Diode bridge circuit 22A, 22B Self-extinguishing element 25 Sync detection circuit 27A, 27B Undervoltage detection circuit 151 Manual changeover switch 141-144 AND gate 145,146 OR gate 149,150 AND gate 151,152 OR gate 153-156 AND gate 158 Gate voltage control circuit

Claims (6)

[Claims] 1. A system switching device for switching a power supply system to a load from one of two power supply systems to the other, wherein a power supply system to the load is mechanically connected between the load and the power supply system. A switching switch for switching to, a semiconductor switching shunt connected in parallel between each system side main contact of the switching switch and a common movable main contact, each consisting of a series circuit of a thyristor switch and a reactor, When performing manual switching between the two power supply systems, an ON command is simultaneously given to the switching command to the switching switch and the thyristor switch connected to the system power supply side of the switching destination to perform output non-interruption switching, In the case of automatic switching that is performed when an abnormality occurs in the power supply system that is supplying power and an undervoltage detection signal is output, first, a switching command is given only to the switching switch, and the main contact of the switching switch is Difference Logic to switch ON / OFF the thyristor switch on the power supply system side after switching after disconnecting from the system side and detecting zero voltage at the device output end or after the momentary disconnection time that does not affect the load A system switching device comprising a gate circuit. 2. A system switching device for switching a power supply system to a load from one of two power supply systems to the other, wherein a power supply system to the load is mechanically connected between the load and the power supply system. A switching switch for switching to, a semiconductor switching shunt connected in parallel between each system side main contact of the switching switch and a common movable main contact, each consisting of a series circuit of a thyristor switch and a reactor, When performing a manual switching between the two power supply systems, the ON command is simultaneously given to the switching command to the switching switch and the thyristor switch connected to the system power supply side of the switching destination to perform the output non-interruption switching, In the case of automatic switching that is carried out when an abnormality occurs in the power supply system during power supply and the power supply current becomes zero, first the switching command is issued only to the switching switch by detecting the zero power supply current on the abnormal system side. However, after the main contact of the switching switch is disconnected from the abnormal system side and a zero voltage is detected at the device output end, or after a momentary interruption time during which the load is not affected, the thyristor switch on the switching destination power system side is turned on. And a logic gate circuit for switching output interruption. 3. A system switching device for switching a power supply system to a load from one of two power supply systems to the other, wherein a power supply system to the load is mechanically connected between the load and the power supply system. And a diode bridge whose AC ends are connected in parallel between the main contacts of each system and a common movable main contact of the switch, and between the DC ends of the diode bridges. When carrying out a manual switching between the semiconductor switching shunt consisting of the connected self-extinguishing element and the two power supply systems, the switching command to the switching switch and the self-extinguishing connected to the system power supply side of the switching destination are performed. In the case of automatic switching that is performed when an ON command is simultaneously given to the arc element and output uninterruptible switching is performed and an undervoltage detection signal is output due to an abnormality in the power supply system that is supplying power, Said cut Only given switching instruction to switch,
And a logic gate circuit for switching the main contact of the switching switch from the power feeding system side to the other system side with a lap period in the self-extinguishing element only during an extremely short opening time. System switching device. 4. A system switching device for switching a power supply system to a load from one of two power supply systems to the other, wherein a power supply system to the load is mechanically connected between the load and the power supply system. And a diode bridge whose AC ends are connected in parallel between the main contacts of each system and a common movable main contact of the switch, and between the DC ends of the diode bridges. When carrying out a manual switching between the semiconductor switching shunt consisting of the connected self-extinguishing element and the two power supply systems, the switching command to the switching switch and the self-extinguishing connected to the system power supply side of the switching destination are performed. In the case of automatic switching that is performed when the power supply system that is supplying power is abnormal and the power supply current becomes zero when the ON command is simultaneously given to the arc element and the output is instantaneously switched, the abnormal system side Power supply First, a switching command is given only to the switching switch when zero is detected, and the self-extinguishing element is operated only during an extremely short opening time when the main contact of the switching switch switches from the power feeding system side to the other system side. And a logic gate circuit for performing switching of the switching switch in the lap period in 1. 5. The system switching device according to claim 2 or 4, further comprising a load current detection circuit for detecting an overcurrent of the load, wherein the logic gate circuit is a dual power supply system during manual switching or automatic switching. When the overcurrent in the power supply lap period from is detected by the load current detection circuit,
A system switching device comprising means for suppressing a wrap current by controlling the voltage of the self-extinguishing element. 6. The system switching device according to claim 5,
The system switching device is characterized in that the logic gate circuit performs non-instantaneous interruption switching by lap switching between systems during manual switching, and instantaneous disconnection switching by gate control of the self-extinguishing element in the case of automatic switching.