JP4992001B2 - DC switch and electrical equipment using DC switch - Google Patents

Description

  The present invention relates to a DC switch suitable for opening or closing a path through which a DC current flows, and an electric device using such a DC switch.

  In recent years, distributed power sources such as solar power generation, wind power generation, and fuel cell power generation have attracted attention. The electric power generated from these distributed power sources is what is called clean energy or new energy. Such generated power from the distributed power source is often DC power, and is different from AC power supplied from a conventional AC power system (commercial power source) using a synchronous generator. .

  When such DC power is supplied to a DC distribution system, for example, indoor wiring, the indoor wiring and an electric circuit such as a television receiver, or a DC motor with a commutator, for example, are used. It is necessary to interpose an appropriate direct current switch between the electrical mechanism and the like (hereinafter, these are collectively referred to as electrical equipment). Here, characteristics required for a DC switch (a switch for conducting / disconnecting DC power) are significantly different from characteristics required for a conventional AC switch (a switch for conducting / disconnecting AC power). . For example, as a switch standardized on the basis of opening and closing of an electric lamp that is lit with alternating current, a small one has been widely used for alternating current, but when such a small one is used with direct current, its use range Is limited to extremely small currents. The reason for this is that in the case of direct current, there is no point in time when the current becomes zero as in the case of alternating current, so the arc generated when opening the mechanical contact is generated continuously without stopping and opened (switch disconnection). This is because the contact cannot be burned out due to the heat generated by the arc. However, when a switch that can be opened while generating an arc is employed, the switch becomes extremely large and unsuitable for use in a conventional home appliance or the like.

  Therefore, a DC switch having a configuration as shown in FIG. 11 has been proposed (see Patent Document 1). That is, a manual operation switch having interlocking mechanical contacts, an input terminal A and an input terminal B in which the plus side and the minus side are electrically connected to the indoor wiring, and a load L to the plus side. And an output terminal C and an output terminal D in which the minus sides are electrically connected to each other, and a positive bus 102 or a negative bus 103 between the input terminal A and the input terminal B and the output terminal C and the output terminal D. Main thyristor 104, a forced commutation circuit configured using auxiliary thyristor 106 to turn off the main thyristor, and a gate trigger voltage circuit for the gate circuit of main thyristor 104 and auxiliary thyristor 106, and manually The operation switch is an interlocking mechanical contact between the input terminal A and the input terminal B and between the output terminal C and the output terminal D. A first contact Sw101 inserted in the lath bus 102 or the negative bus 103, a second contact Sw103 inserted in the gate circuit of the main thyristor, and a third contact Sw102 inserted in the gate circuit of the auxiliary thyristor, The first contact Sw101 is closed (conducting) and the third contact Sw103 is closed (conducting) in that order, and the third contact Sw103 is opened (disconnected) in the turning operation. The second contact point Sw102 is closed (conducted) and the first contact point Sw101 is opened (cut) in order.

In this way, the manual operation switch having three interlocking mechanical contacts Sw101 to Sw103 is combined with the main thyristor 104, and the first contact Sw101 inserted between the input and output terminals is closed during the closing operation. The main thyristor 104 is turned on, and when the circuit is opened, the third contact Sw102 inserted in the gate circuit of the auxiliary thyristor 106 is turned on to operate the commutation circuit including the inductor L101, the capacitor C101, and the auxiliary thyristor 106. When a current in the reverse direction is supplied to the main thyristor 104, and the current flowing through the main thyristor 104 becomes zero (main thyristor is cut), the first contact Sw101 is opened. For this reason, even in the case of direct current, it is said that the direct-current power supplied to the load L can be easily cut off without causing an arc when opening the mechanical contact Sw101 and without causing contact burnout. .

  However, in the method disclosed in Patent Document 1, three interlocking mechanical contacts Sw101 to Sw103 are configured by a rotary switch or the like, and the operator does not operate the timing of conduction and disconnection of the contacts Sw101 to Sw103. In other words, it was necessary to adjust the switching speed of the switch. Further, the mechanism of the mechanical switch provided with the contacts Sw101 to Sw103 is complicated, and the point that the inductor L101 is required as a commutation circuit is inappropriate for the IC, and the entire apparatus is enlarged. Therefore, the object of the present invention is to solve the above-mentioned problems, suitable for opening and closing the DC distribution system, and using a switch with a simple contact configuration to be compatible with various applications and DC rated currents of various sizes. A direct current switch and an electrical device using such a direct current switch are provided.

  In order to solve such a problem, a DC switch according to the present invention includes a mechanical open / close switch and an electronic open / close switch that are inserted to open or close a path through which a direct current flows, and the mechanical open / close switch and the electronic open / close switch. A switch control circuit for controlling a difference between open / close times of the open / close switches, and a control switch for giving an open / close signal to the switch control circuit as a trigger for opening / closing, wherein the switch control circuit is triggered by the open / close signal. After the mechanical opening / closing switch is opened, the mechanical opening / closing switch is opened.

  The DC switch having such a configuration operates as follows. A mechanical open / close switch and an electronic open / close switch inserted in a path through which a direct current flows open or close the current path. The switch control circuit controls the mutual opening / closing time difference between the mechanical opening / closing switch and the electronic opening / closing switch, and the control switch gives an opening / closing signal that triggers opening / closing to the switch control circuit. And since a switch control circuit opens a mechanical opening / closing switch after an electronic opening / closing switch is opened by an opening / closing signal as a trigger, a high voltage is not applied to a mechanical opening / closing switch.

  In order to solve such a problem, another DC switch according to the present invention includes a mechanical on-off switch and an electronic on-off switch that are inserted to open or close a path through which a direct current flows, and interlocked with the mechanical on-off switch. A control switch that controls opening and closing of the electronic switch, and when the mechanical switch is opened, the electronic switch that is controlled by the control switch is opened. When the mechanical opening / closing switch is closed, the electronic opening / closing switch controlled by the control switch is closed.

  The DC switch having such a configuration operates as follows. A mechanical open / close switch and an electronic open / close switch inserted in a path through which a direct current flows open or close the current path. In addition, a control switch is opened / closed in conjunction with the mechanical opening / closing switch to control opening / closing of the electronic opening / closing switch. When the mechanical open / close switch is opened, the electronic open / close switch controlled by the control switch is opened. When the mechanical open / close switch is closed, the electronic open / close switch controlled by the control switch is opened. Since the mechanical open / close switch is closed, no voltage is applied to the mechanical switch after the mechanical open / close switch is disconnected.

  In order to solve such a problem, the electrical device of the present invention includes a mechanical on-off switch and an electronic on-off switch that are inserted to open or close a path through which a direct current flows, the mechanical on-off switch, and the electronic on-off switch. A DC switch comprising: a switch control circuit for controlling a difference between open / close times of the open / close switch; and a control switch for providing an open / close signal to the switch control circuit as an opening / closing trigger; the mechanical open / close switch; and the electronic open / close switch An electrical circuit or an electrical mechanism connected in series with any of the switches, and the switch control circuit of the DC switch is configured to open the mechanical switch after the electronic switch is opened in response to the switch signal. The switch was opened, and the electronic opening / closing switch was closed after the mechanical opening / closing switch was closed.

  Such an electric device having a DC switch and an electric circuit or an electric mechanism configuration operates as follows. A mechanical open / close switch and an electronic open / close switch inserted in a path through which a direct current flows open or close the current path. The switch control circuit controls the mutual opening / closing time difference between the mechanical opening / closing switch and the electronic opening / closing switch, and the control switch gives an opening / closing signal that triggers opening / closing to the switch control circuit. In addition, since the electrical circuit or the electrical mechanism is connected in series with both the mechanical on / off switch and the electronic on / off switch, power can be supplied with one of the mechanical on / off switch or the electronic on / off switch as an open circuit. When the mechanical switch and the electronic switch are closed, power is supplied. The switch control circuit opens the mechanical opening / closing switch after the electronic opening / closing switch is opened in response to the opening / closing signal, and closes the electronic opening / closing switch after the mechanical opening / closing switch is closed. Therefore, in any case, a high voltage is not applied to the mechanical opening / closing switch.

  According to the present invention, a DC switch suitable for opening and closing a DC power distribution system and using a switch having a simple contact configuration and capable of supporting various applications, DC rated currents of various sizes, and such a DC An electrical device using the switch can be provided.

(First embodiment)
A description will be given of the DC switch 20a according to the first embodiment and the electric device 40 including an electric circuit or an electric mechanism as the load 30 according to FIG. In the electric device 40, the input terminal A (+ side) and the input terminal B (− side) are connected to the DC distribution system 10, and the output terminal C (+ side) and the output terminal D (− side) are connected to the load 30. Has been. A DC switch 20 a is inserted between the DC power distribution system 10 and the load 30.

  The DC switch 20 a includes a mechanical open / close switch 16 and an electronic open / close switch 15, a switch control circuit 14, and a control switch 17. Both the mechanical on / off switch 16 and the electronic on / off switch 15 are arranged in series between the DC power distribution system 10 and the load 30.

  The load 30 is, for example, a television receiver as an electric circuit, and the electric mechanism is, for example, a DC motor having a commutator. The mechanical open / close switch 16 and the electronic open / close switch 15 of the direct current switch 20a are configured such that a path through which direct current flows with respect to the load 30 is an open circuit (a state where no current path is formed) or a closed circuit (a state where a current path is formed). Has been inserted to.

  That is, in the plus bus 12 or the minus bus 13 between the input terminal A and the input terminal B and the output terminal C and the output terminal D, both the mechanical on / off switch 16 and the electronic on / off switch 15 are provided. Are connected in series between the DC power distribution system 10 and the load 30. For this reason, when one of the mechanical opening / closing switch 16 and the electronic opening / closing switch 15 is opened (disconnected), the current path is disconnected (opened), and both the mechanical opening / closing switch 16 and the electronic opening / closing switch 15 are turned on. When closed (conductive), the current path is conductive (closed). As a result, power can be supplied to the load 30 or power supply to the load 30 can be cut off.

  The switch control circuit 14 controls the mutual opening / closing time difference between the mechanical opening / closing switch 16 and the electronic opening / closing switch 15. At this time, the control switch 17 gives the switch control circuit 14 an opening / closing signal that triggers opening / closing.

  With reference to FIG. 2, the procedure of opening / closing the control switch 17, the mechanical opening / closing switch 16, and the electronic opening / closing switch 15 will be described with reference to a timing chart. First, the procedure when the current path is closed by the DC switch 20a will be described. The operator changes the control switch 17 from disconnection to conduction (see time t1 in FIG. 2A). The switch control circuit 14 changes the mechanical open / close switch 16 and the electronic open / close switch 15 from disconnection to conduction based on the open / close signal generated by the control switch 17 (see time t1 in FIGS. 2B and 2C). .

  Next, the procedure when the DC switch is opened will be described. The operator changes the control switch 17 from conduction to disconnection (see time t2 in FIG. 2A). The switch control circuit 14 changes the electronic open / close switch 15 from conduction to disconnection based on the open / close signal generated by the control switch 17 (see time t2 in FIG. 2B). Further, the switch control circuit 14 changes the mechanical opening / closing switch 16 from conduction to disconnection after a time τ2 after changing the electronic opening / closing switch 15 from conduction to disconnection based on the opening / closing signal generated by the control switch 17 (FIG. 2). (See time τ2 in (C)).

  When the DC switch is opened in this procedure, that is, when switching from conduction to disconnection, when the mechanical opening / closing switch 16 is opened, the electronic opening / closing switch 15 is already closed (conduction) to opening (disconnection). No voltage is generated across the contact point of the mechanical opening / closing switch 16, and no arc is generated between the contact points.

  With reference to FIG. 3, another procedure when the DC switch is closed will be described with reference to a timing chart. The operator changes the control switch 17 from disconnection to conduction (see time t1 in FIG. 2A). Further, the switch control circuit 14 changes the mechanical opening / closing switch 16 from disconnection to conduction based on the opening / closing signal generated by the control switch 17 (see time t1 in FIG. 2C), and then electronically after a time τ1. The open / close switch 15 is changed from disconnection to conduction (see time τ1 in FIG. 2B).

  Thus, in the case of disconnection to conduction, that is, when the DC switch is closed, when the mechanical on / off switch 16 is on, the electronic on / off switch 15 is not yet in conduction, Since no voltage is applied to the mechanical on / off switch 16, even if chattering (dance) occurs when the contact of the mechanical on / off switch 16 is changed from open to closed, an arc is generated between the contacts of the mechanical on / off switch 16. Will not occur.

  2 and 3, the timing charts shown in FIGS. 2 and 3 can be used to open the circuit, so that arc discharge does not damage the mechanical on / off switch 16, and various simple switches are used. , A DC switch that can cope with DC rated currents of various sizes, and an electric device using such a DC switch can be provided. Since both the mechanical opening / closing switch 16 and the electronic opening / closing switch 15 are used, a highly reliable DC switch is provided because of the high safety from the viewpoint of safety such as electric leakage and a double opening / closing mechanism. Can be realized. In particular, as shown in the timing chart of FIG. 3, when the mechanical opening / closing switch 16 is changed from disconnection to conduction and the electronic opening / closing switch 15 is changed from disconnection to conduction after time τ1, the arc is caused by chattering. It is possible to realize a higher performance and more reliable DC switch that can prevent the occurrence.

  In addition, such a DC switch 20a is not only incorporated in the electric device 40, but is also integrated as a separate component as an adapter for connecting the DC power distribution system 10 and a conventional electric device that operates with electric power from the AC power distribution system. Can be configured. In this case, a plug (not shown) to be plugged into an outlet (not shown) provided in the DC power distribution system 10 is connected to the input terminal A and the input terminal B, and the output terminal C and the output terminal D are the same. Connect the outlet of the shape, keep the switch on the conventional electrical device energized at all times, and use this adapter to safely and easily turn on / off the conventional electrical device (operation / non-operation) Can be.

  In the electric device 40 using such a DC switch 20a, since the DC switch can be reduced in size, the entire electric device 40 can be reduced in size, and ON / OFF of the electric device 40 can be performed safely and easily. Further, when the DC switch 20a is configured as the above-described adapter, it is possible to safely and easily turn on / off (operation / non-operation) of the electric device without any modification to the conventional electric device.

An example of a more specific configuration of the DC switch 20a will be described with reference to FIG. The mechanical opening / closing switch 16 a is a relay (relay) 50 that mechanically opens and closes electrical contacts, and can control the current flowing through the coil winding via the bipolar transistor 51. For example, the contact is closed when a current is passed through the coil winding, and the contact is opened when no current is passed through the coil winding. Electronic off switch 15a is MOS-FET 53 are the (Metal Oxide Semiconductor Field Effect Transi st or), MOS-FET53 by a driving circuit comprising a bipolar transistor 54, the resistor R1 and the resistor R2, so as to open and close the current path Has been made. Here, when the electronic open / close switch 15a is opened, the gate voltage is lowered to increase the resistance between the drain and the source, and when the electronic open / close switch 15a is closed, the gate voltage is increased. Thus, the resistance between the drain and the source is made low.

  The switch control circuit 14a includes a digital logic circuit 18 and a peripheral circuit. The resistor R4 is used to supply the operating voltage of the digital logic circuit 18, and a constant voltage is achieved by the Zener diode ZD and the capacitor C1. The resistor R <b> 3 is used to generate a change between disconnection and conduction of the control switch 17 as an open / close signal and input it to the signal input terminal I of the digital logic circuit 18. The digital logic circuit 18 includes a signal output terminal O1 and a signal output terminal O2. A signal from the signal output terminal O1 is applied to the base of the bipolar transistor 51, and a signal from the signal output terminal O2 is applied to the bipolar transistor 54. Applied to the base. Note that the signal from the signal output terminal O1 has the same polarity as the signal shown in FIG. 2C, and the signal from the signal output terminal O2 has the same timing as the signal shown in FIG. 2B. It is a signal of the opposite polarity.

  The circuit shown in FIG. 5 shows another example in which the electronic opening / closing switch 15a and the mechanical opening / closing switch 16a shown in FIG. 4 are interchanged. The same parts as those shown in FIG. In the circuit shown in FIG. 5, the mechanical on / off switch 16a is always connected to the winding of the relay 50 if the bipolar transistor 51 is ON (the collector and the emitter are in conduction) regardless of the opening / closing of the electronic on / off switch 15a. Since it can be in the closed state, not only the operation according to the timing chart shown in FIG. 2 but also the operation according to the timing chart shown in FIG. 3 can be realized.

  6 and 7 show examples of modifications of the electronic on-off switch and the mechanical on-off switch in the DC switch. Since the connection with other parts in the case of using this modified example in the electric device is the same as in the above-described embodiment, the description of the other parts is omitted. In FIG. 6, the mechanical on / off switch 16b is closed when the base of the bipolar transistor 51b is at a high voltage, and the mechanical on / off switch 16b is opened when the base of the bipolar transistor 51b is at a low voltage. When the base of the bipolar transistor 54b is high voltage, the electronic open / close switch 15b is opened, and when the base of the bipolar transistor 51b is low voltage, the electronic open / close switch 15b is closed.

  In FIG. 7, the mechanical on / off switch 16b is closed when the base of the bipolar transistor 51b is at a high voltage, and the mechanical on / off switch 16b is opened when the base of the bipolar transistor 51b is at a low voltage. When the base of the bipolar transistor 54b is high voltage, the electronic open / close switch 15b is opened, and when the base of the bipolar transistor 51b is low voltage, the electronic open / close switch 15b is closed.

  In the circuit example described above, a MOS-FET is used as an electronic open / close switch, and a bipolar transistor is used as a circuit unit for driving the MOS-FET. In the combination of the two, a MOS-FET, a bipolar transistor, an IGBT, etc. Similar effects can be obtained by any combination of these semiconductor devices. For example, a bipolar transistor can be used as the electronic open / close switch, and a MOS-FET can be used as a circuit unit for driving the bipolar transistor.

( Reference example )
8 to 10 show a DC switch 21a to a DC switch 21c, which are specific examples of the DC switch of the second embodiment. The DC switch according to the second embodiment includes a mechanical open / close switch 55a and an electronic open / close switch 53 (see FIG. 8) or 57 (see FIG. 9) inserted to open or close a path through which a direct current flows. ) Or 58 (see FIG. 10) and a control switch 55b that opens and closes in conjunction with the mechanical on / off switch 55a and controls the electronic on / off switch 53 (or 57 or 58). Is opened by the control switch 55b, and the electronic on / off switch 53 (or 57 or 58) is opened by the control switch 55b. (Or 57 or 58) is closed.

  In the configuration of the second embodiment, the control switch 55b is a two-circuit, two-contact mechanical switch that operates in conjunction with the mechanical opening / closing switch 55a. Here, since the mechanical opening / closing switch 55a is inserted into a current path through which a large current flows, the current capacity is large, and the control switch 55b is inserted into a signal current path through which almost no current flows, and thus the current capacity is small. Is. In any of the circuits shown in FIGS. 8 to 10, when the mechanical opening / closing switch 55a is opened, the electronic opening / closing switch 53 (or 57 or 58) is opened almost simultaneously, and when the mechanical opening / closing switch 55a is closed. At the same time, the electronic open / close switch 53 (or 57 or 58) is also closed.

  Therefore, in the operation of the second embodiment, when the mechanical on / off switch 55a is operated from the closed state to the open state, even if an arc is generated between the contacts of the mechanical on / off switch 55a, the electronic on / off switch 53 (or 57 or 58) is also open, so the arc stops instantaneously. Further, except that both the electronic on / off switch 53 (or 57 or 58) and the mechanical on / off switch 55a fail and are closed, the path through which the direct current flows is not closed, and the number of parts is small. It operates as a highly reliable DC switch from the viewpoint of ensuring safety.

It is a block diagram of the electric equipment using the direct current switch of 1st Embodiment. It is a timing chart of operation | movement of the DC switch of 1st Embodiment. It is another timing chart of operation | movement of the DC switch of 1st Embodiment. It is a specific example of 1st Embodiment. It is another specific example of 1st Embodiment. It is another specific example of the DC switch of the first embodiment. It is another specific example of the DC switch of the first embodiment. It is a specific example of the DC switch of the second embodiment. It is another specific example of the DC switch of the second embodiment. It is another specific example of the DC switch of the second embodiment. It is a DC switch of the background art.

Explanation of symbols

10 DC distribution system, 14, 14a Switch control circuit, 15, 15a, 15b, 53 Electronic on / off switch, 16, 16a, 16b, 55a Mechanical on / off switch, 17 Control switch, 18 Digital logic circuit, 20a, 21a, 21b , 21c DC switch, 30 load, 40 electrical equipment, 51, 51b, 54, 54b Bipolar transistor, 55b Control switch, A, B input terminal, C, D output terminal, C1 capacitor, ZD Zener diode

Claims (2)

A mechanical on / off switch and an electronic on / off switch inserted to open or close a path through which a direct current from a DC distribution system flows;
A switch control circuit for controlling a difference between open and close times of the mechanical open / close switch and the electronic open / close switch connected in series to the mechanical open / close switch;
A control switch for providing an opening / closing signal that triggers opening / closing to the switch control circuit;
With
The switch control circuit includes:
After the electronic open / close switch is opened with the open / close signal as an opportunity, the mechanical open / close switch is opened,
A DC switch characterized in that the mechanical open / close switch and the electronic open / close switch are simultaneously closed in response to the open / close signal. A mechanical on / off switch and an electronic on / off switch inserted to open or close a path through which a direct current from a DC distribution system flows;
A switch control circuit for controlling a difference between open and close times of the mechanical open / close switch and the electronic open / close switch connected in series to the mechanical open / close switch;
A control switch for providing an opening / closing signal that triggers opening / closing to the switch control circuit;
A DC switch comprising:
An electrical circuit or electrical mechanism connected in series with both the mechanical on / off switch and the electronic on / off switch;
With
The switch control circuit includes:
The mechanical on / off switch is opened after the electronic on / off switch is opened in response to the on / off signal,
An electrical device characterized in that the mechanical on-off switch and the electronic on-off switch are simultaneously closed in response to the on-off signal.

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