CN218241637U

CN218241637U - On-off device

Info

Publication number: CN218241637U
Application number: CN202221138890.9U
Authority: CN
Inventors: 不公告发明人
Original assignee: Shenzhen Nanyun Microelectronics Co ltd
Current assignee: Shenzhen Nanyun Microelectronics Co ltd
Priority date: 2022-05-12
Filing date: 2022-05-12
Publication date: 2023-01-06
Anticipated expiration: 2032-05-12

Abstract

The utility model discloses an on-off device, which is an eight-end structure and is applied to a three-phase four-wire alternating current power supply system, and comprises a first breakpoint, a second breakpoint, a third breakpoint, a first arc extinguishing circuit, a second arc extinguishing circuit, a third arc extinguishing circuit, a fourth arc extinguishing circuit, a fifth arc extinguishing circuit and a sixth arc extinguishing circuit, wherein the first breakpoint, the second breakpoint and the third breakpoint are in linkage work; six arc extinguishing circuits equally divide into two sets ofly, and one of them is located one side of three breakpoint, and another set of opposite side that is located the breakpoint after the on-off unit inserts three-phase four-wire AC power supply system, only a set of arc extinguishing circuit work, and a set of arc extinguishing circuit will lose the arc extinguishing effect in addition to the on-off unit not only has prevents the transposition function, can also reduce the risk that components and parts became invalid among the on-off unit, improves the reliability of on-off unit.

Description

On-off device

Technical Field

The patent of the utility model relates to an extinguish the electric arc of breakpoint when the disconnection, in particular to on-off device.

Background

The arc is a physical phenomenon which is often encountered when a break point formed by a mechanical switch such as a contactor, a circuit breaker, a relay, a connector, a plug, a fuse link and the like is broken, because when the break point breaks current, the break point and a medium around the break point contain a large amount of electrons which can be dissociated, and when an external voltage and a break point contact point are heated sufficiently, strong electric dissociation and thermal dissociation are generated to cause the medium to be punctured, so that the arc is generated. Electric arc harm is very big, can influence power supply system's reliability on the one hand, and on the other hand probably causes incident such as conflagration, consequently need take necessary arc extinguishing measure reliably to extinguish electric arc, the utility model discloses the breakpoint that will contain the arc extinguishing measure is called the on-off unit.

For a direct current power supply system, the current cannot naturally zero, and arc extinguishing measures are generally required; for ac power supply systems, arc extinguishing measures are generally required when the capacity is above 10A. The general measures are to add an arc extinguishing chamber including a structural member such as an arc extinguishing grid or a partition plate, which makes the structure of the on-off device more complicated, and to some extent, causes an increase in volume and an increase in cost.

For the on-off device applied to a three-phase three-wire ac power supply system, generally, one arc extinguishing circuit is respectively disposed between each two phase lines, and 3 arc extinguishing circuits are provided in total to extinguish the arc generated when the break point in the corresponding loop is disconnected, for representative documents, refer to chinese patent documents with publication numbers CN2807432Y and CN202384266U, fig. 1-1 are circuit diagrams of an embodiment of the on-off device in the patent document with publication number CN2807432Y, and fig. 1-2 are circuit diagrams of an embodiment of the on-off device in the patent document with publication number CN 202384266U.

For the on-off device applied to the three-phase four-wire alternating current power supply system, an arc extinguishing circuit is generally arranged in a loop formed by each phase wire and a ground wire, and the connection relation of the fig. 1-1 and the fig. 1-2 is adjusted according to the rule.

The inventor of the application notices that the on-off device applied to the three-phase four-wire alternating current power supply system at least comprises eight ports, the wiring is complex, once the wiring is wrong, the arc extinguishing circuit fails, in order to realize the reverse connection prevention function of the on-off device, the arc extinguishing circuits in the figures 1-1 and 1-2 introduce a rectifier bridge to rectify the alternating voltage, so that the circuit is complex, the failure risk is increased, and the reliability of the on-off device is reduced.

It should be noted that the above information disclosed in this background section is only intended to enhance an understanding of the general background of the application and should not be taken as an acknowledgement or any form of suggestion that this information forms part of the prior art already known to a person skilled in the art.

SUMMERY OF THE UTILITY MODEL

Therefore, the to-be-solved technical problem of the utility model is to provide an on-off device, be applied to three-phase four-wire AC power supply system, solve one of the technical problem that exists among the prior art at least to a certain extent.

Therefore, the utility model provides an on-off device's embodiment as follows:

the utility model provides an on-off device, is eight end structures, is applied to three-phase four-wire AC power supply system, wherein:

the arc extinguishing device comprises a first breakpoint, a second breakpoint, a third breakpoint, a first arc extinguishing circuit, a second arc extinguishing circuit, a third arc extinguishing circuit, a fourth arc extinguishing circuit, a fifth arc extinguishing circuit and a sixth arc extinguishing circuit, wherein the first breakpoint, the second breakpoint and the third breakpoint are in linkage work, namely, the first breakpoint, the second breakpoint and the third breakpoint are closed and disconnected simultaneously during work; one end of the first breakpoint is connected with one end of the first arc extinguishing circuit to serve as a first end of the on-off device, one end of the second breakpoint is connected with one end of the second arc extinguishing circuit to serve as a second end of the on-off device, one end of the third breakpoint is connected with one end of the third arc extinguishing circuit to serve as a third end of the on-off device, and the other end of the third arc extinguishing circuit serves as a fourth end of the on-off device; the other end of the first breakpoint is connected with one end of the fourth arc extinguishing circuit and then serves as a fifth end of the on-off device, the other end of the second breakpoint is connected with one end of the fifth arc extinguishing circuit and then serves as a sixth end of the on-off device, the other end of the third breakpoint is connected with one end of the sixth arc extinguishing circuit and then serves as a seventh end of the on-off device, and the other end of the sixth arc extinguishing circuit serves as an eighth end of the on-off device; the fourth end and the eighth end of the on-off device are connected together;

the first arc extinguishing circuit, the second arc extinguishing circuit and the third arc extinguishing circuit are a first group and are used for extinguishing electric arcs generated when the first breakpoint, the second breakpoint and the third breakpoint are disconnected; the fourth arc extinguishing circuit, the fifth arc extinguishing circuit and the sixth arc extinguishing circuit are a second group and are also used for extinguishing electric arcs generated when the first breakpoint, the second breakpoint and the third breakpoint are disconnected; after the on-off device is connected to the three-phase four-wire alternating-current power supply system, only one group of arc extinguishing circuits works when the first breakpoint, the second breakpoint and the third breakpoint are disconnected.

Preferably, any one, two or three of the first break point, the second break point and the third break point are break points formed by a moving contact and a fixed contact of a contactor, break points formed by a moving contact and a fixed contact of a relay, break points formed by a moving contact and a fixed contact of a circuit breaker, or break points formed by an insert of a plug and a slot corresponding to a socket.

Further, any one, any two, any three, any four, any five or six of the first arc extinguishing circuit, the second arc extinguishing circuit, the third arc extinguishing circuit, the fourth arc extinguishing circuit, the fifth arc extinguishing circuit and the sixth arc extinguishing circuit is a non-control type arc extinguishing circuit.

As a specific implementation manner of the first arc extinguishing circuit, the second arc extinguishing circuit, the third arc extinguishing circuit, the fourth arc extinguishing circuit, the fifth arc extinguishing circuit, and the sixth arc extinguishing circuit, each arc extinguishing circuit is the same and includes a first diode, a second diode, a capacitor, and a bidirectional clamping device, a cathode of the first diode and an anode of the second diode are connected together and then serve as one end of each arc extinguishing circuit, an anode of the first diode and a cathode of the second diode are connected to one end of the capacitor at the same time, and the other end of the capacitor serves as the other end of each arc extinguishing circuit, and the bidirectional clamping device is connected in parallel with the capacitor.

Preferably, the bidirectional clamping device is a bidirectional TVS tube or a plurality of bidirectional TVS tubes connected in series, a voltage dependent resistor or a plurality of voltage dependent resistors connected in series, a gas discharge tube or a plurality of gas discharge tubes connected in series, or any combination of the bidirectional TVS tube, the voltage dependent resistor and the gas discharge tubes.

Furthermore, the first end and the fifth end of the on-off device are used for being connected to a first phase line of the three-phase four-wire alternating-current power supply system, the second end and the sixth end of the on-off device are used for being connected to a second phase line of the three-phase four-wire alternating-current power supply system, the third end and the seventh end of the on-off device are used for being connected to a third phase line of the three-phase four-wire alternating-current power supply system, and the fourth end and the seventh end of the on-off device are used for being connected to a ground wire of the three-phase four-wire alternating-current power supply system; the first end, the second end, the third end and the fourth end of the on-off device are used for being connected to a power supply side of the three-phase four-wire alternating-current power supply system, and the fifth end, the sixth end, the seventh end and the eighth end of the on-off device are used for being connected to a load side of the three-phase four-wire alternating-current power supply system; or the first end, the second end, the third end and the fourth end of the on-off device are used for being connected to the load side of the three-phase four-wire alternating-current power supply system, and the fifth end, the sixth end, the seventh end and the eighth end of the on-off device are used for being connected to the power supply side of the three-phase four-wire alternating-current power supply system.

As an equivalent alternative to the above embodiment, either one or both of the first diode and the second diode are replaced by: a plurality of diodes are connected in series in the same direction, a unidirectional TVS tube or a plurality of unidirectional TVS tubes are connected in series in the same direction, or the diodes and the unidirectional TVS tubes are combined in any number and then connected in series in the same direction.

Compared with the prior art, the embodiment of the utility model provides a following beneficial effect has at least:

1. the embodiment of the utility model provides an in including six arc extinguishing circuits in the on-off device, evenly divide into two sets ofly, one of them a set of one side that is located three breakpoint, another a set of opposite side that is located three breakpoint, after the on-off device inserts three-phase four-wire AC power supply system, only a set of arc extinguishing circuit work, a set of arc extinguishing circuit will lose the arc extinguishing effect in addition to still reduced the risk that components and parts became invalid in the on-off device when realizing preventing the function of connecing, improved the reliability of on-off device.

2. The utility model discloses the on-off device can not make great change to the outward appearance of device to still be eight terminal structure, can be compatible with the on-off device that adopts prior art, thereby can not change the user habit.

3. The embodiment of the utility model provides an arc extinguishing circuit among the on-off device constitutes for electronic components, adopts the scheme that the explosion chamber carries out the arc extinguishing in prior art relatively, can simplify the structure of on-off device to reduce volume, reduce cost.

4. Two sets of arc extinguishing circuits of the on-off device in the embodiment are positioned on two sides of the three breakpoints, so that the whole on-off device is ensured to meet the physical isolation requirement.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.

Drawings

FIG. 1-1 is a circuit diagram of an embodiment of a switching device disclosed in patent document with publication number CN 2807432Y;

fig. 1-2 is a circuit diagram of an embodiment of the on-off device disclosed in patent document CN 202384266U;

FIG. 2 is a schematic block diagram of an embodiment of the on/off device of the present invention;

fig. 3 is a specific circuit diagram of an embodiment of the on-off device of the present invention and its application;

FIG. 4 is a schematic diagram of the on-off device of FIG. 3 with the current in the phase A and phase B lines reversed;

FIG. 5 is a schematic view of the on-off device of FIG. 3 with the ports reversed.

Detailed Description

Based on the inventive concept of the present application, it can be understood that the present invention is inventive in that two sets of arc extinguishing circuits are disposed in the on-off device, and arc extinguishing is realized by one set of arc extinguishing circuit, so as to reduce the wiring requirement for eight ports of the on-off device, and it is not necessary to adopt any kind of arc extinguishing circuit specifically, each arc extinguishing circuit given in fig. 3 is only a better example, when facing different application scenarios, the technicians in the field can select or design separately according to the actual situation, and the present invention does not limit this.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with other figures are described in detail below, and it is apparent that the described embodiments are some, not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the terms "comprises" and "comprising," and any variations thereof, as used in the description and claims of this application, are intended to cover a non-exclusive inclusion, such that the inclusion of a list of elements or unit circuits is not necessarily limited to those elements or unit circuits explicitly listed, but may include elements or unit circuits not explicitly listed or inherent to such circuits.

In addition, the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

It will be understood that when an element is referred to in the specification and claims as being "connected" to another element, it can be "directly connected" to the other element or "connected" to the other element through a third element.

Fig. 3 is a schematic block diagram of an embodiment of the on-off device of the present invention, please refer to fig. 3, the on-off device of the present embodiment is an eight-terminal structure, and is applied to a three-phase four-wire ac power supply system, including a first breakpoint K1, a second breakpoint K2, a third breakpoint K3, a first arc-extinguishing circuit, a second arc-extinguishing circuit, a third arc-extinguishing circuit, a fourth arc-extinguishing circuit, a fifth arc-extinguishing circuit, and a sixth arc-extinguishing circuit, where the first breakpoint K1, the second breakpoint K2, and the third breakpoint K3 are linked to work, that is, they are closed and disconnected simultaneously during work; one end of a first breakpoint K1 is connected with one end of a first arc extinguishing circuit and then serves as a first end of the on-off device, one end of a second breakpoint K2 is connected with one end of a second arc extinguishing circuit and then serves as a second end of the on-off device, one end of a third breakpoint K3 is connected with one end of a third arc extinguishing circuit and then serves as a third end of the on-off device, and the other end of the third arc extinguishing circuit serves as a fourth end of the on-off device; the other end of the first breakpoint K1 is connected with one end of the fourth arc-extinguishing circuit to serve as a fifth end of the on-off device, the other end of the second breakpoint K2 is connected with one end of the fifth arc-extinguishing circuit to serve as a sixth end of the on-off device, the other end of the third breakpoint K3 is connected with one end of the sixth arc-extinguishing circuit to serve as a seventh end of the on-off device, and the other end of the sixth arc-extinguishing circuit serves as an eighth end of the on-off device; the fourth end and the eighth end of the on-off device are connected together;

the first arc extinguishing circuit, the second arc extinguishing circuit and the third arc extinguishing circuit are a first group and are used for extinguishing electric arcs generated when the first breakpoint K1, the second breakpoint K2 and the third breakpoint K3 are disconnected; the fourth arc extinguishing circuit, the fifth arc extinguishing circuit and the sixth arc extinguishing circuit are a second group and are also used for extinguishing electric arcs generated when the first breakpoint K1, the second breakpoint K2 and the third breakpoint K3 are disconnected; after the on-off device is connected into a three-phase four-wire alternating current power supply system, only one group of arc extinguishing circuits works when the first breakpoint K1, the second breakpoint K2 and the third breakpoint K3 are disconnected.

The embodiment of the utility model provides an in including six arc extinguishing circuits in the on-off device, evenly divide into two sets ofly, one of them a set of one side that is located three breakpoint, another a set of opposite side that is located three breakpoint, after the on-off device inserts three-phase four-wire AC power supply system, only a set of arc extinguishing circuit work, a set of arc extinguishing circuit will lose the arc extinguishing effect in addition to still reduced the risk that components and parts became invalid in the on-off device when realizing preventing the function of connecing, improved the reliability of on-off device.

The utility model discloses the on-off device can not make great change to the outward appearance of device to still be six terminal structure, can be compatible with the on-off device that adopts prior art, thereby can not change the user habit.

The embodiment of the utility model provides an arc extinguishing circuit among the on-off device is electronic components and constitutes, compares in prior art and adopts the explosion chamber to carry out the scheme of arc extinguishing, can simplify the structure of on-off device to reduce volume, reduce cost.

Two sets of arc extinguishing circuits of the on-off device in the embodiment are positioned on two sides of the three breakpoints, so that the whole on-off device is ensured to meet the physical isolation requirement.

Further, any one, two or three of the first breakpoint K1, the second breakpoint K2 and the third breakpoint K3 are breakpoints formed by a moving contact and a fixed contact of the contactor, a moving contact and a fixed contact of the relay, a moving contact and a fixed contact of the circuit breaker, or breakpoints formed by an insertion piece of the plug and a corresponding insertion slot of the socket.

Furthermore, any one, any two, any three, any four, any five or six of the first arc extinguishing circuit, the second arc extinguishing circuit, the third arc extinguishing circuit, the fourth arc extinguishing circuit, the fifth arc extinguishing circuit and the sixth arc extinguishing circuit is an uncontrolled arc extinguishing circuit, namely, no components and parts, such as a silicon controlled rectifier, a thyristor and the like, which can work only through detection and triggering are arranged in the arc extinguishing circuit, so that the complexity of the device is avoided from being increased.

Fig. 3 is a specific circuit diagram of an embodiment of the on-off device of the present invention and its application, please refer to fig. 3: the first arc extinguishing circuit, the second arc extinguishing circuit, the third arc extinguishing circuit, the fourth arc extinguishing circuit, fifth arc extinguishing circuit and sixth arc extinguishing circuit are the same, all include first diode, the second diode, electric capacity and two-way clamping device, be each arc extinguishing circuit one end after first diode negative pole and second diode positive pole link together, electric capacity one end is connected simultaneously to first diode positive pole and second diode negative pole, the electric capacity other end is each arc extinguishing circuit other end, two-way clamping device is parallelly connected with the electric capacity.

Specifically, the components and the connection relation included in each arc extinguishing circuit are as follows:

the first arc extinguishing circuit comprises a diode D1a, a diode D2a, a capacitor C1a and a first bidirectional clamping device, the cathode of the diode D1a is connected with the anode of the diode D2a to form one end of the first arc extinguishing circuit, the anode of the diode D1a and the cathode of the diode D2a are simultaneously connected with one end of the capacitor C1a, the other end of the capacitor C1a is the other end of the first arc extinguishing circuit, and the first bidirectional clamping device is connected with the capacitor C1a in parallel;

the second arc extinguishing circuit comprises a diode D1b, a diode D2b, a capacitor C1b and a second bidirectional clamping device, the cathode of the diode D1b is connected with the anode of the diode D2b to form one end of the second arc extinguishing circuit, the anode of the diode D1b and the cathode of the diode D2b are simultaneously connected with one end of the capacitor C1b, the other end of the capacitor C1b is the other end of the second arc extinguishing circuit, and the second bidirectional clamping device is connected with the capacitor C1b in parallel;

the third arc extinguishing circuit comprises a diode D1C, a diode D2C, a capacitor C1C and a third bidirectional clamping device, the cathode of the diode D1C is connected with the anode of the diode D2C to form one end of the third arc extinguishing circuit, the anode of the diode D1C and the cathode of the diode D2C are simultaneously connected with one end of the capacitor C1C, the other end of the capacitor C1C is the other end of the third arc extinguishing circuit, and the third bidirectional clamping device is connected with the capacitor C1C in parallel;

the fourth arc extinguishing circuit comprises a diode D1D, a diode D2D, a capacitor C1D and a fourth bidirectional clamping device, the cathode of the diode D1D is connected with the anode of the diode D2D to form one end of the fourth arc extinguishing circuit, the anode of the diode D1D and the cathode of the diode D2D are simultaneously connected with one end of the capacitor C1D, the other end of the capacitor C1D is the other end of the fourth arc extinguishing circuit, and the fourth bidirectional clamping device is connected with the capacitor C1D in parallel;

the fifth arc extinguishing circuit comprises a diode D1e, a diode D2e, a capacitor C1e and a fifth bidirectional clamping device, the cathode of the diode D1e is connected with the anode of the diode D2e to form one end of the fifth arc extinguishing circuit, the anode of the diode D1e and the cathode of the diode D2e are simultaneously connected with one end of the capacitor C1e, the other end of the capacitor C1e is the other end of the fifth arc extinguishing circuit, and the fifth bidirectional clamping device is connected with the capacitor C1e in parallel;

the sixth arc extinguishing circuit comprises a diode D1f, a diode D2f, a capacitor C1f and a sixth bidirectional clamping device, the cathode of the diode D1f is connected with the anode of the diode D2f to form one end of the sixth arc extinguishing circuit, the anode of the diode D1f and the cathode of the diode D2f are simultaneously connected with one end of the capacitor C1f, the other end of the capacitor C1f is the other end of the sixth arc extinguishing circuit, and the sixth bidirectional clamping device is connected with the capacitor C1f in parallel.

The first bidirectional clamping device is a bidirectional TVS tube T1a, the second bidirectional clamping device is a bidirectional TVS tube T1b, the third bidirectional clamping device is a bidirectional TVS tube T1c, the fourth bidirectional clamping device is a bidirectional TVS tube T1d, the fifth bidirectional clamping device is a bidirectional TVS tube T1e, and the sixth bidirectional clamping device is a bidirectional TVS tube T1f.

The utility model discloses on-off device is for being applied to three-phase four-wire AC power supply system's on-off device, and the first phase line among the three-phase four-wire AC power supply system is the A phase line, and the second phase line is the B phase line, and the third phase line is the C phase line, and the fourth line is the N ground wire. In the connection mode in fig. 3, the first to third arc extinguishing circuits are located on the power supply side of the three-phase four-wire ac power supply system, and at this time, the fourth to sixth arc extinguishing circuits located on the load side of the three-phase four-wire ac power supply system extinguish the arc generated by the first to third breakpoints when the arc is disconnected. Specifically, the fourth arc-extinguishing circuit extinguishes an electric arc generated when the first breakpoint K1 breaks a loop formed by the phase line a and the ground line N, the fifth arc-extinguishing circuit extinguishes an electric arc generated when the second breakpoint K2 breaks a loop formed by the phase line B and the ground line N, and the sixth arc-extinguishing circuit extinguishes an electric arc generated when the third breakpoint K3 breaks a loop formed by the phase line C and the ground line N.

The three-phase alternating current is output by the power supply of the circuit in fig. 3, and the working process of the first breakpoint K1 for arc extinction thereof in the breaking process is described by taking the example that the on-off device needs to be disconnected when the current flows from one end of the first breakpoint K1 to the other end, and taking the arc generated when the fourth arc extinction circuit extinguishes the first breakpoint K1 to break the loop formed by the phase line a and the ground line N.

After the on-off device in fig. 3 is connected to the three-phase four-wire ac power supply system, when a current flows from one end of the first breakpoint K1 to the other end, the diode D2a is turned on, the capacitor C1a is charged, and the first arc extinguishing circuit does not work any more after the capacitor C1a is fully charged; first breakpoint K1 is after first closure, and diode D2D switches on, and electric capacity C1D charges, and first breakpoint K1 realizes the arc extinguishing to first breakpoint K1 by fourth arc extinguishing circuit at follow-up breaking process, and concrete process is as follows:

(1) Ignition arc phase

When the first breaking point K1 starts to open, strong electrical dissociation and thermal dissociation between the contacts can occur, which causes the air dielectric around the contacts to be broken down, and the arc is ignited.

(2) Arc sustained combustion phase

After the arc is ignited, along with the gradual increase of the contact gap of the first breakpoint K1, the rate of the decrease of the arc resistance caused by the temperature increase is smaller than the rate of the increase of the arc resistance caused by the increase of the gap, the arc resistance starts to increase, the voltage generated at the two ends of the load RL1 is reduced, the increasing trend of the voltage UK1 at the two ends of the first breakpoint K1 is ensured, and the arc combustion process enters a dynamic stable state. The rising rate of the voltage UK1 at the two ends of the first breakpoint K1 and the reduction rate of the current I1 flowing through the first breakpoint K1 can achieve the condition of stable combustion of the electric arc, namely, the relation between the voltage value UK1 and the current value I1 can move along the negative resistance characteristic curve graph of the electric arc and be automatically adjusted.

(3) At the moment of current injection, the conditions for stable combustion of the arc are destroyed

When the voltage at the two ends of the load RL1 is reduced to a value that the voltage at the cathode of the diode D1D is less than the voltage of the voltage source U1 output by the power supply source to the phase line A and the ground line N, the diode D1D is conducted, the capacitor C1D discharges to inject the current I2 into the load RL1, so that the current I3 flowing through the load RL1 is changed from I1 to (I1 + I2), the voltage at the two ends of the load RL1 is increased, the voltage at the other end of the first breakpoint K1 is raised, the natural rising speed of the voltage UK1 at the two ends of the first breakpoint K1 is reduced, the stable negative resistance characteristic relation between the rising speed of the voltage UK1 at the two ends of the first breakpoint K1 and the reducing speed of the current I1 flowing through the first breakpoint K1 is destroyed, and the condition of dynamic stable combustion of the electric arc is destroyed.

(4) The current is injected continuously, the electric arc burns and enters negative feedback, and the electric arc tends to be extinguished

In the disconnection process of the first breakpoint K1, the gap for separating the contacts is larger and larger, so that the electric arc is stably burnt, the voltage required for puncturing the medium around the contacts is also larger and larger, namely the voltage UK1 at the two ends of the first breakpoint K1 is required to be larger and larger, but along with the injection of the discharge current I2 into the load RL1, the voltage at the other end of the first breakpoint K1 is raised, the rising rate of the voltage UK1 at the two ends of the first breakpoint K1 is smaller than the rate of maintaining the dynamic stable burning of the electric arc, and the electric arc burning enters negative feedback circulation, namely, the electric arc is smaller and tends to be extinguished.

(5) Parasitic inductance back electromotive force follow current stage

When the load RL1 includes an inductive load such as a motor, parasitic inductance is generated. After the arc burning enters a negative feedback state, the reduction rate of the current I1 is very high, the current in the parasitic inductance is not allowed to change suddenly (the parasitic inductance is more obvious when the parasitic inductance is larger), and the parasitic inductance can generate a reverse electromotive force, the phase line A, the first breakpoint K1, the load RL1 and the N ground wire form a circuit loop, namely an additional power supply is connected in series between the first breakpoint K1 and a voltage source U1 of the power supply power source for outputting the phase line A and the N ground wire, and the power supply and the voltage source U1 are connected in series in the same direction, so that the voltage at two ends of the first breakpoint K1 is increased.

The energy in the capacitor C1D is firstly drawn away by the back electromotive force generated by the parasitic inductor, then the capacitor C1D is charged, when the capacitor C1D is fully charged (the capacitor C1D is restored to the state capable of extinguishing the arc again, and energy injection is provided when the first breakpoint K1 is disconnected again), the surplus energy in the parasitic inductor will follow current through a loop formed by the load RL1, the bidirectional TVS tube T1D and the diode D1D, and the bidirectional TVS tube T1D and the diode D1D will clamp the back electromotive force (the back voltage, that is, the voltage at the other end of the first breakpoint K1) of the load RL1 to the sum of the clamping voltage of the bidirectional TVS tube T1D and the forward conduction voltage drop of the diode D1D, so that the voltage at the two ends of the first breakpoint K1 is prevented from increasing continuously, and thus the tendency of extinguishing the arc is not changed, and the arc extinguishing is ensured. Meanwhile, the capacitance value required by effective arc extinction of the capacitor C1d alone is greatly reduced, the cost is reduced, and breakdown damage of the capacitor C1d due to bearing of overhigh voltage can be avoided.

The circuit of fig. 4 can rapidly extinguish the arc because the voltage at the other end of the first break point K1 is clamped to the sum of the clamping voltage of the bidirectional TVS tube T1D and the forward conduction voltage drop of the diode D1D.

In the embodiment, the bidirectional TVS tube T1D and the diode D1b are connected in series in the same direction, the total clamping voltage is the sum of the clamping voltages of the two components, the voltage stress required to be borne by the clamping device is dispersed, and the risk of failure of the clamping device is reduced.

(6) Moment of arc extinction

When the gap between the contacts of the first breaking point K1 is continuously increased, the arc resistance is further increased, so that the arc current (i.e., the current I1) is further decreased, and when the arc current is decreased to such a level that the arc cannot be maintained, the discharge disappears, at which time the arc is extinguished.

Fig. 4 is a schematic diagram of the switching device in fig. 3 after the current in the phase line a and the ground line N is reversed, when the switching device in the circuit in fig. 3 is in a situation that the current needs to be disconnected when flowing from the other end to one end of the first breakpoint K1, the arc extinguishing process is the same as that described above, and the difference lies in that: after the on-off device is connected to a power supply system, the diode D1a is conducted to ensure that the capacitor C1a is fully charged, so that the first arc extinguishing circuit does not work any more; after the first breakpoint K1 is closed for the first time, the diode D1D is conducted, the capacitor C1D is charged, the first breakpoint K1 is conducted for the diode D2D in the follow-up disconnection process, the current is injected into the capacitor C1D, the current I3 flowing through the load RL1 is changed into (I1 + I2) from I1, the voltages at two ends of the load RL1 are increased, and the voltage at the other end of the first breakpoint K1 is raised.

Fig. 5 is a schematic diagram of the on-off device of fig. 3 with the ports reversely connected, please refer to fig. 5, the connection mode is that the fourth to sixth arc extinguishing circuits are located at the power supply side of the three-phase four-wire ac power supply system, and at this time, the first to third arc extinguishing circuits located at the load side of the three-phase four-wire ac power supply system extinguish the arc generated when the first to third breakpoints are disconnected. Specifically, the first arc extinguishing circuit extinguishes an arc generated when the first breakpoint K1 breaks a loop formed by the phase line a and the ground line N, the second arc extinguishing circuit extinguishes an arc generated when the second breakpoint K2 breaks a loop formed by the phase line B and the ground line N, and the third arc extinguishing circuit extinguishes an arc generated when the third breakpoint K3 breaks a loop formed by the phase line C and the ground line N. The circuits of the on-off devices in fig. 3 and 5 have symmetry, and when the on-off device needs to be disconnected in the case that the current flow directions of the loops formed by the phase lines and the ground line in the wiring method in fig. 5 are different, the specific arc extinguishing process corresponds to the wiring method shown in fig. 3, and is not repeated.

Based on the above description, it is conceivable to optimize fig. 3/5 as follows:

and replacing the bidirectional TVS tubes in the arc extinguishing circuits with: a plurality of two-way TVS pipes are established ties, and a piezo-resistor or a plurality of piezo-resistor establish ties, and a gas discharge tube or a plurality of gas discharge tube establish ties, or establish ties after arbitrary kind and arbitrary quantity combination of two-way TVS pipe, piezo-resistor and gas discharge tube. The purpose of using a plurality of devices in series is to not only further reduce the withstand voltage requirement for the devices, but also to adjust the magnitude of the voltage value limited when the back electromotive voltage is limited.

It should be noted that, as can be understood from the specific connection manners shown in fig. 3 and 5, the functions of each port in the on-off device according to the embodiment of the present invention are as follows:

the first end and the fifth end of the on-off device are used for being connected to a first phase line of the three-phase four-wire alternating-current power supply system, the second end and the sixth end of the on-off device are used for being connected to a second phase line of the three-phase four-wire alternating-current power supply system, the third end and the seventh end of the on-off device are used for being connected to a third phase line of the three-phase four-wire alternating-current power supply system, and the fourth end and the seventh end of the on-off device are used for being connected to a ground wire of the three-phase four-wire alternating-current power supply system;

the first end, the second end, the third end and the fourth end of the on-off device are used for being connected to a power supply side of the three-phase four-wire alternating-current power supply system, and the fifth end, the sixth end, the seventh end and the eighth end of the on-off device are used for being connected to a load side of the three-phase four-wire alternating-current power supply system; or the first end, the second end, the third end and the fourth end of the on-off device are used for being connected to the load side of the three-phase four-wire alternating-current power supply system, and the fifth end, the sixth end, the seventh end and the eighth end of the on-off device are used for being connected to the power supply side of the three-phase four-wire alternating-current power supply system.

Furthermore, it is conceivable to optimize fig. 3 as follows:

any one or two of the first diode and the second diode in each arc extinguishing circuit are replaced by: a plurality of diodes syntropy are established ties, one-way TVS pipe or a plurality of one-way TVS pipe syntropy are established ties, perhaps the diode syntropy is established ties after arbitrary quantity and the arbitrary quantity combination of one-way TVS pipe, not only can reduce the withstand voltage requirement to the device, can also adjust the moment that the electric current pours into.

The above are only embodiments of the present invention, and it should be especially noted that the above embodiments should not be considered as limitations of the present invention, and for those skilled in the art, a plurality of modifications and decorations can be made without departing from the spirit and scope of the present invention, and these modifications and decorations should also be considered as protection scope of the present invention.

Claims

1. The utility model provides an on-off device, is eight end structures, is applied to three-phase four-wire AC power supply system, its characterized in that:

the arc extinguishing device comprises a first breakpoint, a second breakpoint, a third breakpoint, a first arc extinguishing circuit, a second arc extinguishing circuit, a third arc extinguishing circuit, a fourth arc extinguishing circuit, a fifth arc extinguishing circuit and a sixth arc extinguishing circuit, wherein the first breakpoint, the second breakpoint and the third breakpoint are in linkage work, namely, the first breakpoint, the second breakpoint and the third breakpoint are closed and disconnected simultaneously during work; one end of the first breakpoint is connected with one end of the first arc extinguishing circuit and then serves as a first end of the on-off device, one end of the second breakpoint is connected with one end of the second arc extinguishing circuit and then serves as a second end of the on-off device, one end of the third breakpoint is connected with one end of the third arc extinguishing circuit and then serves as a third end of the on-off device, and the other end of the third arc extinguishing circuit serves as a fourth end of the on-off device; the other end of the first breakpoint is connected with one end of the fourth arc extinguishing circuit and then serves as a fifth end of the on-off device, the other end of the second breakpoint is connected with one end of the fifth arc extinguishing circuit and then serves as a sixth end of the on-off device, the other end of the third breakpoint is connected with one end of the sixth arc extinguishing circuit and then serves as a seventh end of the on-off device, and the other end of the sixth arc extinguishing circuit serves as an eighth end of the on-off device; the fourth end and the eighth end of the on-off device are connected together;

2. The on-off device of claim 1, wherein: any one, two or three of the first breakpoint, the second breakpoint and the third breakpoint are breakpoints formed by a moving contact and a fixed contact of a contactor, a moving contact and a fixed contact of a relay, a moving contact and a fixed contact of a circuit breaker, or breakpoints formed by an insert of a plug and a slot corresponding to a socket.

3. The on-off device according to claim 1, wherein: any one, any two, any three, any four, any five or six of the first arc extinguishing circuit, the second arc extinguishing circuit, the third arc extinguishing circuit, the fourth arc extinguishing circuit, the fifth arc extinguishing circuit and the sixth arc extinguishing circuit is a non-control type arc extinguishing circuit.

4. The on-off device of claim 1, wherein: the first arc extinguishing circuit, the second arc extinguishing circuit, the third arc extinguishing circuit, the fourth arc extinguishing circuit, the fifth arc extinguishing circuit and the sixth arc extinguishing circuit are the same, and all include first diode, second diode, electric capacity and two-way clamping device, first diode negative pole with be each arc extinguishing circuit one end after the second diode positive pole links together, first diode positive pole with the second diode negative pole is connected simultaneously electric capacity one end, the electric capacity other end is each arc extinguishing circuit other end, two-way clamping device with the electric capacity is parallelly connected.

5. The on-off device according to claim 4, wherein: the bidirectional clamping device is formed by connecting a bidirectional TVS tube or a plurality of bidirectional TVS tubes in series, connecting a piezoresistor or a plurality of piezoresistors in series, connecting a gas discharge tube or a plurality of gas discharge tubes in series, or connecting the bidirectional TVS tube, the piezoresistor and the gas discharge tubes in series after any kind and any number of the bidirectional TVS tubes, the piezoresistors and the gas discharge tubes are combined.

6. The on-off device according to claim 1, wherein:

7. The on-off device according to any of claims 4 to 6, wherein either one or both of the first diode and the second diode is replaced by: a plurality of diodes are connected in series in the same direction, a unidirectional TVS tube or a plurality of unidirectional TVS tubes are connected in series in the same direction, or the diodes and the unidirectional TVS tubes are combined in any number and then connected in series in the same direction.