JP3420281B2 - Power supply switching device and switching device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a changeover switch device for switching electric power from two power sources and supplying the electric power to a load. The present invention relates to a power supply switching device and a transfer switching device which can be advantageously implemented for switching and supplying to a power supply.

[0002]

2. Description of the Related Art Conventionally, a mechanical switching means for performing a switching operation by mechanically moving a movable contact, which is a so-called mechanical switch, between electric power from a commercial AC power source and electric power from a private power generation facility. Power is supplied to the load via the.

[0003]

In such a prior art, when the movable contact moves from one fixed contact to another fixed contact, the load is supplied with electric power for a relatively long time of, for example, about 10 to 20 msec. A momentary power failure occurs that is not supplied. Therefore, when the load is, for example, a mercury lamp, it is turned off by such an instantaneous power failure, and it takes time to re-light. Also, when the load is a computer, a momentary power failure causes a malfunction. When the load is a fluorescent lamp, it turns off when an instantaneous power failure occurs,
Can not provide comfortable lighting.

An object of the present invention is to eliminate a conventional instantaneous power failure for a relatively long time, and to perform a switching operation without causing a substantial instantaneous power failure. Is to provide.

[0005]

The present invention comprises: (a) a first three-phase AC power supply; and (b) a first line for supplying electric power for each phase of the first three-phase AC power supply. (c) a second three-phase AC power supply; and (d) a second line that supplies electric power for each phase from the second three-phase AC power supply and individually corresponds to the first line, and (e) A third line that supplies electric power to a three-phase load and individually corresponds to the first and second lines, and (f) lines corresponding to each of the first to third phases are individually provided. Each of the changeover switches includes (f1) switching means, and one of the two individual contacts selectively makes contact with the common contact to perform a mechanical changeover operation. The individual contacts are respectively connected to the first and second lines corresponding to each phase, and the common contacts are the first and second lines. A switching means connected to the third line corresponding to each line of, is connected between the common contact with one of the individual contact (f2),
A first semiconductor switching means capable of forcibly extinguishing, and (f3) connected between the other individual contact and the common contact,
A changeover switch having a second semiconductor switching means capable of forcibly extinguishing; (g) a control means for switching the changeover switch for each phase; a first semiconductor switching means; In connection with the semiconductor switching means, the synchronization points of the first and second three-phase AC power supplies are detected, and the first switching means is conducted in a state where the common contact is conducted to one individual contact, and Shorter than the first time during the first time during which the second semiconductor switching means is cut off and the common contact is cut off from the two individual contacts when the common contact is switched from one individual contact to the other. Shutting off the first and second semiconductor switching means for a second time, and then shutting off the first semiconductor switching means, and connecting the second semiconductor switching means to the individual contacts of the common contact of the other. After the common contact is conducted to the other individual contact before conducting the conduction to the contact, the switching control for shutting off the second semiconductor switching means is performed, and this switching control is performed by 3
It is a power supply switching device characterized by including a control means which performs at the same time.

The present invention also provides (a) one of two individual contacts.
One selectively contacts the common contact for mechanical switching operation, each of these two individual contacts is a fixed contact, the common contact is a movable contact, and has an auxiliary switch for detecting movement of the movable contact. A switching means; (b) a first semiconductor switching means connected between one individual contact and a common contact; and (c) a second semiconductor switching means connected between the other individual contact and a common contact. And (d) control means responsive to the output of the auxiliary switch, wherein the first switching means is turned on and the second semiconductor switching means is turned off while the common contact is turned on with one of the individual contacts, During a first time during which the common contact disconnects from the two individual contacts as the common contact switches from one to the other individual contact, a second time shorter than the first time, the first and First The semiconductor switching means is cut off, then the first semiconductor switching is cut off, and the second semiconductor switching means is made conductive before the common contact is made conductive to the other individual contact, and the common contact is made to the other individual contact. And a control unit that shuts off the second semiconductor switching unit after the second semiconductor switching unit is turned on.

[0007]

According to the present invention, the electric power from the first three-phase AC power supply and the second three-phase AC power supply is switched to the three-phase load via the changeover switch by detecting the synchronization point. However, the first and second semiconductor switching means provided in this changeover switch have a configuration capable of forcibly extinguishing the arc, and switching control for each phase is controlled by the control means.
Do at the same time. In particular, according to the invention, each of the two individual contacts of the mechanical switching means is, for example, a fixed contact and the common contact is a movable contact, the common contact being in conduction from one of the individual contacts to the other. In switching to individual contacts to conduct electricity, for example, a common contact, which is a movable contact, is moving from one individual contact to the other individual contact, and the common contact is not conducting to any individual contact. In time, for example, the second of about 3 μsec
In order to cut off only for the time of, and to eliminate a substantial instantaneous blackout,
In the present invention, the first and second semiconductor switching means are connected between one individual contact and the common contact and between the other individual contact and the common contact, respectively, and the common contact conducts with the one individual contact. The first semiconductor switching means is turned on, and the first semiconductor switching means is kept turned on after the common contact is separated from the one individual contact, and then the first semiconductor switching means is turned off. A state in which the common contact is cut off from the two individual contacts and the first and second semiconductor switching means is cut off is achieved for a second time shorter than the first time, and thereafter, The second semiconductor switching means is electrically connected before the common contact is electrically connected to the other individual contact.

As mentioned above, during the second time, the common contact is not in contact with the two individual contacts and the first and second semiconductor switching means are also interrupted, so that each of the two individual contacts is closed. It is possible to prevent an inconvenient state in which, for example, power supplies or the like connected to each other are connected to each other via the first and second semiconductor switching means. Since the second time is, for example, 3 μsec, the load is not adversely affected even if the power supply is interrupted for such an extremely short time.

According to the present invention, the state in which the common contact is not in contact with any of the two individual contacts can be detected by the auxiliary switch provided in the mechanical switching means. This auxiliary switch can be realized by attaching an auxiliary contact to an armature that operates integrally with a movable contact, for example, a common contact.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an electric circuit diagram showing the overall construction of an embodiment of the present invention. Each electric power from the three-phase commercial AC power supply 1 and the three-phase private power generation equipment 2 is switched to the load 4 via the mechanical switching means 3 called a mechanical switch to be supplied with the electric power. This mechanical switching means 3
The present invention is carried out in order to prevent substantially no instantaneous power failure during the switching operation of the switching mode.
The output terminals UC, VC, WC of the power supply 1 are connected to the line 5,
6, 7 and output terminals UI, V of the power generation equipment 2
I and WI are connected via lines 8, 9 and 10 to each of the three pairs of individual contacts 11a, 1 of the mechanical switching means 3.
1b; 12a, 12b; 13a, 13b, respectively, and their respective common contacts 11c, 12c, 13c are
Terminals UO, V of the load 4 via lines 14, 15, 16
O and WO are connected respectively. Regarding lines 5 and 14, between one individual contact 11a and common contact 11c, between lines 6 and 15, between one individual contact 12a and common contact 12c, and further regarding lines 7 and 16,
Between the one individual contact 13a and the common contact 13c, 3
The respective first semiconductor switching means 17, 18 and 19 are respectively connected. Similarly, regarding each line 8, 9, 10 and lines 14, 15, 16 of the power generation equipment 2,
The other individual contacts 11b, 12b, 13b and the common contact 11
Three second semiconductor switching means 20, 21 and 22 are respectively connected between c, 12c and 13c. In the first semiconductor switching means 17, four diodes D1 to D4 form a bridge 23 and are connected, and a transistor 25 which is a semiconductor switching element is provided on one diagonal line 24 of the bridge 23.
Remaining semiconductor switching means 18, 19; 20, 2
1, 22 also have a similar configuration. The configuration of the second semiconductor switching means 20 is the same as the configuration of the first semiconductor switching means 17 as described above, and the corresponding parts are designated by the same reference numerals with a subscript a. In the first semiconductor switching means 17, the AC half-cycle current from the power supply 1 via the line 5 is transferred from the line 5 to the diode D.
1 through transistor 25, diode D4 to line 1
4 to the terminal UO of the load 4 and in the next half cycle from line 14 to diode D3, transistor 25 and diode D2 to line 5 to power supply 1. In this way, AC power can be supplied from the power supply 1 to the load 4 by using the transistor 25 forming the unidirectional current path. This also applies to the remaining semiconductor switching means 18, 19; 20, 21, 22.

FIG. 2 is a diagram showing the structure of the mechanical switching means 3. Three common contacts 11c, 12c, 13
c is a movable contact, which is attached to one Amatia 26, and its common contacts 11c, 12c, and 13c are selectively excited by the two coils M1 and M2.
Individual contacts 11a and 11b which are fixed contacts; 12a and 12
b; A switching operation in which the switching mode is switched by selectively contacting 13a and 13b is achieved. The mechanical switching means 3 is a so-called latching relay that maintains the switching switching operation during the excitation immediately before the demagnetization of the coil M1 or M2. However, as another embodiment, the excitation of the coils M1 and M2 is performed. It may be configured to keep the switching operation inside, or alternatively, the coils M1 and M2.
Only one of them is provided and its one coil M1,
The switching state may be switched by exciting and demagnetizing M2. The mechanical switching means 3 may have other configurations.

The mechanical switching means 3 further includes individual contacts 11 of the common contacts 11c, 12c and 13c.
a, 11b; 12a, 12b; 13a, 13b, one or more auxiliary switches 27 are attached to detect the movement during the switching movement. This auxiliary switch 27
Is a movable contact 28 attached to the armature 26.
And a contact 29 provided at a fixed position, and the common contacts 11c, 12c, 13c are the individual contacts 11a, 11
b; 12a, 12b; during the first period when it is not in contact with any of 13a, 13b, the contacts 28, 29 operate to shut off, whereby the common contact 11c, which is a movable contact,
It functions to detect movement of 12c and 13c.

Referring again to FIG. 1, a control circuit 31 for controlling the first semiconductor switching means 17, 18, and 19,
The control circuit 32 for controlling the second semiconductor switching elements 20, 21, 22 is connected to another control circuit 33, and the auxiliary switch 27 is connected to the control circuit 33. These control circuits 31, 32 and 33 are control means 3
Make up 4. In the control circuit 33, a switching command signal is generated from the switching command signal generation circuit 35 via the line 36, and the control circuits 31, 32, 33 are operated by this, and a switching operation in which an instantaneous power failure does not substantially occur. To achieve.

The operation will be described with reference to FIG. Time t1
Previously, it is assumed that the mechanical switching means 3 is in the switching state shown in FIG. 1 and the power from the power source 1 is supplied to the load 4. When a switching command signal is generated from the switching command signal generation circuit 35 at time t1, the control circuit 33 causes the coil M2 of the mechanical switching means 3 to operate.
Are excited as shown in FIG. 3 (5), whereby the common contact 11c of the mechanical switching means 3 is
As shown in (1), it disconnects from the individual contact 11a after time t3, and this common contact 11c contacts and conducts with another individual contact 11b after time t6 shown in FIG. 3 (2). The first time W1 from time t3 to t6 is, for example, 10 to 20 msec, and during the first time W1,
The common contact 11c, which is a movable contact, is one individual contact 11a.
And moves so as to be electrically connected to the other individual contact 11b. The state of the first time W1 can be detected by the control circuit 33 receiving the output of the auxiliary switch 27. The control circuit 33 gives a signal to the control circuit 31, whereby the control circuit 31 gives the base control signal to the transistor 25 of the first semiconductor switching means 17 for a period of time t2 to t4 shown in FIG. 3 (3). Make it conductive. That is, the common contact 11c is the individual contact 11
While the transistor 25 is conducting with the transistor a, the transistor 25 is conducting, and the transistor 25a of the second semiconductor switching means 20 remains blocked as shown in FIG. 3 (4). The control circuit 32 controls the operation of the transistor 25a in response to the signal from the control circuit 33.

First detected by auxiliary switch 27
At time W1, the transistor 25 is cut off at time t4 in FIG. 3 (3) by the action of the control circuits 31 and 33, and at time t5 after the subsequent second time W2 elapses.
The control circuit 32 controls the transistor 25a in FIG.
Conduction is performed at time t5 in (4). Second time W2
Is, for example, 3 μsec, which is an extremely short time.
Therefore, even if the power supply is interrupted for such a short time W2, the load 4 is not adversely affected.

After the time t5 in the first time W1, the transistor 25a is conducting, and at this time the transistor 25 remains cut off, and at the subsequent time t6, the common contact 11c becomes the individual contact 11b as shown in FIG. 3 (2). As shown in FIG. After that, at time t7, the control circuit 32 cuts off the transistor 25a. Thus, the load 4 is switched from the power source 1 to the power generation facility 2 as shown in FIG. At time t3, the transistor 2
The conduction of 5 prevents the occurrence of sparks when the common contact 11c is separated from the individual contact 11a and cut off.

At time t8, when a switching command signal is generated from the switching command signal generation means 35 to command switching of the power supply from the power generation equipment 2 to the power source 1, the control circuit 33 changes to the state shown in FIG. As shown, the coil M1 of the mechanical switching means 3 is excited. The control circuit 33
By giving a signal to the control circuit 32, as shown in FIG. 3 (4), the second semiconductor switching means 20 is activated at time t9.
The transistor 25a of FIG. 3 is turned on, and then, FIG.
At time t10, the common contact 11c of the mechanical switching means 3 separates from the individual contact 11b and is cut off at time t10, and as shown in FIG. 3 (1), at time t13.
, The common contact 11c is switched to the individual contact 11a to conduct electricity, and thus, during the first time W1, the common contact 11c.
Is not in contact with any of the two individual contacts 11b and 11a. During the first time W1 from time t10 to time t13, the control circuit 32 turns off the transistor 25a at time t11, and then the second time W2.
At time t12 after the lapse of time, the control circuit 31 makes the transistor 25 conductive as shown in FIG. The transistor 25 is turned off at time t14 after the time t13 has elapsed. In this way, the power source is switched from the power generation facility 2 to the power source 1. In FIG. 3 above, the first and second
Although the operation has been described in relation to the semiconductor switching means 17, 20, the remaining first semiconductor switching means 18, 19 and the second semiconductor switching means 21, 2 are left.
Similar operations are performed at the same time in relation to item 2. The mechanical switching means 3 is a latching relay that maintains the switching state in the excited state immediately before the demagnetization of the coil M2 and the coil M1. Therefore, in this embodiment, after the time t7 and the time t14, the power consumption is reduced. Coil M2, M1 in order to reduce
The power supply to the power supply is cut off.

FIG. 4 shows a simplified principle of another embodiment of the present invention. This embodiment is a simplified version of the embodiment shown in FIGS. 1 to 3, and the power source 1 may be single-phase or direct current, and the mechanical switching means may be used. The operation of the semiconductor switching means 17 and 20 is achieved during the first time when the interruption of 3 is performed, and the power is cut off for the extremely short second time, so that a substantial instantaneous power failure does not occur. It

FIG. 5 is an electric circuit diagram of still another embodiment of the present invention. In FIG. 5, portions corresponding to those in the above-described embodiment are indicated by the same reference numerals or the same reference numerals with subscripts a, b and c. For the groups of loads 4a, 4b, 4c having different fluctuation patterns in which the loads fluctuate with time, the switching means 3a, 3b,
By using 3c, it is possible to perform frequent switching between the commercial alternating-current power supply 1 and the private power generation equipment 2 in accordance with a load change with substantially no interruption. As a result, the power generation equipment 2 can always be operated in the vicinity of the rating, and the load factor of the power generation equipment 2 can be improved. In such a configuration, each load 4
Load detecting means 37, 38, 3 such as an ammeter or a power meter for detecting the load which is the power consumption of a, 4b, 4c.
9, and the control means 34 responds to the outputs of these load detection means 37, 38, 39 to switch the first semiconductor switching means 17a, 17b, 17c and the second semiconductor switching means 20a, 20b, 20c. Control by changing the state.

As an alternative embodiment, it is also possible to arrange to detect the current or power of the load inside the mechanical switching means.

FIG. 6 is a diagram for explaining the operation of the control means 34 of the embodiment shown in FIG. With the passage of time, the total power consumed by the loads 4a, 4b, 4c changes with the passage of time. The rated power of the power generation facility 2 is indicated by reference numeral P3. Before time t21 when the power consumption P1 is less than the rated power P3, the power generation facility 2 is used by using the second semiconductor switching means 20a, 20b, 20c.
Power is supplied to the loads 4a, 4b, 4c, and the total power consumption P4 exceeds the rated power P3 during the period from time t21 to t22. Therefore, as shown in FIG. 5, for example, the mechanical switching means 3c. Only the power from the power source 1 is applied to the load 4c. From time t22 to t23, the total power consumption P2 is less than the rated power P3, so all the mechanical switching means 3a, 3b, 3c.
Supplies the electric power from the power generation equipment 2 to the loads 4a, 4b, 4c, respectively.

As another embodiment of the present invention, the output electric power of the private power generating equipment 2 of FIG. 5 is detected by the load detecting means 40, and the mechanical switching means 3a, 3 according to the present invention.
It is also possible to switch the switching states of b and 3c.

FIG. 7 is a simplified electrical circuit diagram of another embodiment of the present invention. This embodiment is similar to the previous embodiment, and the corresponding parts bear the same reference numerals. Load 4a,
4b and 4c are, for example, motors, which require a large current at the time of startup, so that power is supplied from the commercial AC power supply 1 to the loads 4a, 4b, and 4c at the time of startup, and power is generated for private use after completion of startup. The mechanical switching means 3 are operated according to the invention so as to switch to the supply of power from the installation 2. As a result, it is possible to avoid the burden of a large starting current of the private power generation equipment 2. Therefore, without increasing the rating of the private power generation equipment 2 more than necessary for the loads 4a, 4b, 4c such as motors,
The generator capacity can be selected according to the steady load.

Further, as another embodiment of the present invention, when the commercial AC power source 1 is restored after a power failure occurs in the commercial AC power source 1, a private power generation facility 2 which is an emergency generator.
The power switching operation from the power supply to the commercial AC power supply can be performed according to the present invention.

Yet another embodiment of the present invention is shown in FIG. This embodiment is also similar to the above-mentioned embodiment, and the corresponding portions bear the same reference numerals. As described above, according to the present invention, the mechanical switching means 3 is operated according to the present invention by the restoration of the commercial AC power supply 1 while the private power generation equipment 2 which is the emergency generator is operating during the power failure of the commercial AC power supply 1. The operation can be performed, and the power supply can be switched with virtually no interruption.

Further, when the private power generation equipment 2 trips, the residual AC voltage 1 and the synchronization point are detected by the residual voltage to prevent the powers 4c and 4d from being momentarily stopped or stopped, and the power supply can be switched. it can.

As another embodiment of the present invention, in order to detect the movement of the movable contact of the mechanical switching means, instead of providing the auxiliary switch in the above-mentioned embodiment, the current flowing between the individual contact and the common contact is changed. It may be configured to detect and determine that the individual contact and the common contact are separated when the detected current becomes zero.

The first and second semiconductor switching means may use semiconductor switching elements capable of forcibly extinguishing the arc so as to perform switching control in three phases simultaneously.

[0029]

As described above, according to the present invention, the first three
The power from the three-phase alternating current power supply and the second three-phase alternating current power supply is detected at the synchronization point and switched to the three-phase load via the changeover switch to be supplied to the first and second changeover switches. The semiconductor switching means has a configuration capable of forcibly extinguishing the arc, and performs switching control for each phase.
The control means performs three phases simultaneously. In particular, first and second semiconductor switching respectively connected between each individual contact and the common contact during a first time when the common contact of the mechanical switching means is not in contact with any of the two individual contacts. By operating the means to shut off both semiconductor switching means for a second time shorter than the first time, it is possible to prevent mutual connection of, for example, a power supply connected to each individual contact, Moreover, by setting the second time to an extremely short time such as 3 μsec, it is possible to prevent a substantial momentary power failure and continuously supply power to the load without a power interruption.

Further, according to the present invention, when the common contact of the mechanical switching means is not electrically connected to the two individual contacts, an auxiliary switch for detecting the movement of the movable contact,
It can be easily realized by providing the mechanical switching means.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing the overall configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a specific electrical configuration of a mechanical switching means 3.

FIG. 3 is a diagram for explaining the operation of the embodiment shown in FIGS. 1 and 2.

FIG. 4 is a simplified electric circuit diagram of another embodiment of the present invention.

FIG. 5 is an electric circuit diagram showing a simplified configuration of another embodiment of the present invention.

FIG. 6 is a diagram for explaining the operation of the embodiment shown in FIG.

FIG. 7 is an electric circuit diagram showing a simplified configuration of still another embodiment of the present invention.

FIG. 8 is an electric circuit diagram showing a simplified configuration of still another embodiment of the present invention.

[Explanation of symbols]

1 Commercial AC Power Supply 2 Private Power Generation Equipment 3 Mechanical Switching Means 4, 4a-4d Loads 11a, 11b; 12a, 12b; 13a, 13b Individual Contacts 11c, 12c, 13c Common Contacts 17, 18, 19 First Semiconductor Switching Means 20 , 21, 22 Second semiconductor switching means 23 Bridge 24 Diagonal line 25 Transistor 27 Auxiliary switch 31, 32, 33 Control circuit 34 Control means 35 Switching command signal generating means

Continuation of the front page (56) Reference JP-A-4-229033 (JP, A) JP-A-4-334934 (JP, A) JP-A-5-22993 (JP, A) JP-A-62-244230 (JP , A) JP-A-61-58432 (JP, A) JP-A-2-60428 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02J 3/00-5/00 H02J 9/00-9/08

Claims (2)

(57) [Claims] 1. (a) a first three-phase AC power supply; (b) a first line for supplying power for each phase of the first three-phase AC power supply; and (c) a second three-phase AC power supply. A power supply, (d) power for each phase from a second three-phase AC power supply, and a second line individually corresponding to the first line, and (e) power for a three-phase load. , A third line individually corresponding to the first and second lines, and (f) a changeover switch provided individually corresponding to the lines for each of the first to third phases. The switch is (f1) a switching means, in which one of the two individual contacts selectively contacts the common contact to perform a mechanical switching operation, and one individual contact and the other individual contact are in each phase. The common contact is connected to each of the corresponding first and second lines, and the common contact is connected to each of the first and second lines. Three
A switching means connected to the line, and (f2) connected between one individual contact and a common contact,
A first semiconductor switching means capable of forcibly extinguishing, and (f3) connected between the other individual contact and the common contact,
A changeover switch having a second semiconductor switching means capable of forcibly extinguishing; (g) a control means for switching the changeover switch for each phase; a first semiconductor switching means; In relation to the semiconductor switching means, the synchronization points of the first and second three-phase AC power supplies are detected, and the first switching means is conducted in a state where the common contact is conducted to one individual contact, and Shorter than the first time during the first time during which the second semiconductor switching means is cut off and the common contact is cut off from the two individual contacts when the common contact is switched from one to the other individual contact. The first and second semiconductor switching means are shut off for a second time, then the first semiconductor switching means is shut off, and the second semiconductor switching means is connected to the other common contact. Control means for conducting three phases simultaneously with switching control for conducting the second semiconductor switching means after conducting the common contact with the other individual contact before conducting the other contact. A power supply switching device comprising: 2. (a) One of the two individual contacts selectively contacts the common contact to perform a mechanical switching operation, and each of these two individual contacts is a fixed contact, and the common contact is a movable contact. Switching means having an auxiliary switch for detecting movement of the movable contact, (b) first semiconductor switching means connected between one individual contact and a common contact, and (c) another individual contact A second semiconductor switching means connected between the common contact and (d) a control means responsive to the output of the auxiliary switch, wherein the first switching means is in a state in which the common contact is electrically connected to one of the individual contacts. During the first time during which the common contact is cut off from the two individual contacts when the common contact is switched from one individual contact to the other individual contact. time of The first and second semiconductor switching means are cut off for a second time shorter than that, and then the first semiconductor switching means is cut off, and the second semiconductor switching means is connected to the common contact with the other individual contact. 1. A changeover switch device, further comprising: a control unit that first conducts electricity, and that interrupts the second semiconductor switching means after the common contact electrically conducts to the other individual contact.