WO2021190666A1

WO2021190666A1 - Arc extinguishing device

Info

Publication number: WO2021190666A1
Application number: PCT/CN2021/085138
Authority: WO
Inventors: 郭桥石; 刘建德; 贾宝华
Original assignee: 郭桥石
Priority date: 2020-04-03
Filing date: 2021-04-01
Publication date: 2021-09-30
Also published as: CN115210834A

Abstract

An arc extinguishing device for an arc of a mechanical switch (K), comprising an arc extinguishing electrode (B1). During a turn-off process of the mechanical switch (K) requiring arc extinguishing, an arc between contact points (A1, A2) of the mechanical switch (K) is connected to the arc extinguishing electrode (B1), and the arc extinguishing electrode (B1) is used for inputting an arc extinguishing current. The arc extinguishing device has the advantages of being simple, having high safety and facilitating implementation.

Description

Arc extinguishing device

Technical field

The invention relates to an arc extinguishing device for mechanical switching arcs, in particular to an arc extinguishing device that is simple, high in safety and convenient to implement.

Background technique

At present, in the electronic control system, in order to overcome the arc burning loss of the mechanical switch, the mechanical switch is usually connected in parallel with electronic components (capacitors, semiconductor switches and other components) for arc extinguishing, which has safety problems such as low withstand voltage and easy breakdown.

Summary of the invention

The purpose of the present invention is to solve the aforementioned problems and provide an arc extinguishing device that is simple, has high pressure resistance and safety, and is convenient to implement.

The purpose of the present invention is achieved through the following technical solutions:

An arc extinguishing device includes an arc extinguishing electrode. During the breaking process of a mechanical switch that requires arc extinguishing, the arc between the contacts of the mechanical switch is connected to the arc extinguishing electrode, and the arc extinguishing electrode is used to input the arc extinguishing current (ie The current used for arc extinguishing).

Working principle: As shown in Figure 1, including the arc extinguishing electrode B1, when the contacts A1 (first contact) and A2 (second contact) of the mechanical switch K are disconnected, between the contact A1 and the contact A2 The arc is connected to the arc extinguishing electrode B1, and the contact A2 can be set to connect the load. The arc extinguishing electrode B1 provides a pulse current to the load through the arc between B1 and A2 to realize the arc between B1 and A1 (front arc ) Arc extinguishing. After the pulse current passes, the arc between B1 and A2 (back arc) is extinguished. The entire arc extinguishing process is completed. The number of mechanical switches K is one or more.

The invention has the advantages of reasonable design, simplicity, high pressure resistance, high safety, and convenient implementation.

Description of the drawings

Figure 1 is a schematic diagram of the arc extinguishing device of the present invention.

Fig. 2 is a schematic diagram of the first embodiment of the arc extinguishing device of the present invention.

Fig. 3 is a schematic diagram of the second embodiment of the arc extinguishing device of the present invention.

Fig. 4 is a schematic diagram of the third embodiment of the arc extinguishing device of the present invention.

Detailed ways

The first embodiment of the arc extinguishing device of the present invention:

As shown in Figure 2, including the arc extinguishing electrode B1, the mechanical switch K of this embodiment is a bridge (double break point) structure, and the contact A1, the contact A2, and the contact bridge A3 are in the arc extinguishing chamber G (that is, the arc extinguishing cavity In ), the arc extinguishing object is between the contact A1 (the first contact, the first static contact) and the contact A2 (the second contact, the second static contact, which can be set to connect to the load end) of the mechanical switch K The arc includes the first arc formed by the contact bridge A3 and the contact A1 and the second arc formed by the contact bridge A3 and the contact A2. During the breaking process of the mechanical switch K, the second arc is connected to the arc extinguishing electrode B1, and the arc is extinguished Electrode B1 provides electric pulse (arc extinguishing current) to the second arc to extinguish the arc. When the arc extinguishing electrode B1 fails to extinguish the arc, the first arc and the arc extinguishing piece G1 (the wall of the arc extinguishing cavity, or the arc extinguishing grid, etc.) Equivalent device) is connected, the arc extinguishing piece G1 extinguishes the first arc, which is beneficial to reduce the influence of the arc on the insulation of the arc extinguishing chamber and improve the electrical life of the mechanical switch K.

In this embodiment, the arc extinguishing electrode B1 of each mechanical switch K is the same node.

The second embodiment of the arc extinguishing device of the present invention:

As shown in Figure 3, it includes an arc extinguishing electrode B1, an uncontrollable device D1 (D2, an uncontrollable semiconductor switch, preferably a diode), a mechanical switch K for arc extinguishing, and an uncontrollable device D1 (D2) for each The mechanical switches are isolated, each arc extinguishing electrode B1 is connected through an uncontrollable device D1 (D2), and the uncontrollable device D1 (D2) is connected by a common cathode or (and) a common anode. The node N1 or common cathode of the common anode The node N2 is used to input the current for arc extinguishing.

This embodiment is a bidirectional DC or AC arc extinguishing circuit. When it is used for unidirectional DC or AC synchronous arc extinguishing, you can choose one of the uncontrollable devices D1 or D2, the uncontrollable device and the controllable device Compared with the advantages of strong overload capacity and no need for control circuit control.

The above embodiments may also include a capacitor as a current source for providing arc extinguishing current. One end of the capacitor is connected to N1 (N2, or the arc extinguishing electrode B1), and the other end of the capacitor is connected to A1 (or the power supply connected to the A1 end) or A2. The capacitor can be connected to a discharge element (a resistor, or a discharge switch), and the capacitor can also form a series circuit (two-terminal circuit) with a voltage detection switch (a delay switch can be used). One end of the series circuit is connected to N1 (N2, or arc extinguishing electrode B1) is connected, and the other end of the series circuit is connected to A1 (or the power supply connected to A1) or A2.

The third embodiment of the arc extinguishing device of the present invention:

On the basis of the above embodiment, it also includes a current source U that provides arc extinguishing current. As shown in FIG. 4, the current source U includes a first switch S1 (preferably a fully-controlled semiconductor switch, such as a field effect transistor, a triode IGBT and other devices, you can also choose a relay, or a contactor, or a mechanical switch such as a circuit breaker. When a semi-controlled semiconductor device is used, a capacitor in series is required), control unit C, current limiting element R1 (option, resistance) The first switch S1 and the current limiting element R1 are connected in series with the arc extinguishing electrode B1. The control signal of the first switch S1 is provided by the control unit C. The control unit C is used to detect the voltage of the arc extinguishing electrode B1 (such as the first switch S1 in In the open or cut-off state, preferably the voltage of B1 relative to A2, or the voltage of B1 relative to the load ground) or current (for example, when the first switch S1 is in the closed or conducting state), the arc is detected, and the mechanical switch K is connected. The power supply (a power supply with an output voltage greater than the working voltage of the load connected to the mechanical switch K can also be used, or a capacitor to provide the power) provides the arc extinguishing current of the arc extinguishing electrode B1 through the first switch S1 (that is, the first switch S1 is connected to A1 When an arc occurs between the contacts A1 and A2 of the mechanical switch K during the breaking process of the mechanical switch K, the current source U outputs a pulse current to the arc extinguishing electrode B1 (when the first switch S1 When in the closed or conducting state, the control unit C delays the control of the first switch S1 to open or cut off) to achieve arc extinguishing, and the current-limiting element R1 (option, resistor) is used for current-limiting protection.

In the third embodiment, the control signal of the mechanical switch K can also be provided by the control unit C, or (and) the control signal of the mechanical switch K (or synchronization signal, which can be provided by the auxiliary switch of the mechanical switch) is transmitted to the control unit C, Or (and) the voltage signal (the voltage at both ends of the load, or the voltage at both ends of the mechanical switch, or the voltage at the connection end relative to other nodes) between the mechanical switch K and the load is transmitted to the control unit C, which is beneficial to the control unit C. The arc status of each path is effectively screened. The control unit C preferably has a built-in microcontroller or programmable logic device and other programmable devices; the control unit C can perform real-time control or delay control on the first switch S1; J1 is the control port (option ), J2 is a communication port (option); the control unit is used to detect the voltage or current of the arc extinguishing electrode (add a corresponding current sensor), or the control unit is used to detect the voltage or current of the power supply ( Increase the corresponding current sensor).

In the first and third embodiments, according to requirements, uncontrollable devices can also be connected in series with each arc extinguishing electrode (refer to the circuit shown in Fig. 3).

In the above embodiment, the voltage of the current source of the arc extinguishing current input to the node N1 (N2) can be greater than the (same polarity) working voltage of the load connected to the mechanical switch K. The above embodiment is used for AC (or AC synchronous arc extinguishing) Or DC arc extinguishing.

In the above embodiment, the arc includes the front arc (B1 and A1 section) that is extinguished first and the back arc (B1 and A2) that is extinguished later. In the breakpoint structure, the distance between the arc extinguishing electrode B1 and the movable contact A1 (as shown in Figure 3) in the disconnected state is greater than the distance between the arc extinguishing electrode B1 and the static contact A2, which is beneficial to reduce the burning loss of the mechanical switch, and When the voltage of the arc extinguishing current is greater than the voltage of the power supply of the mechanical switch, it is beneficial to reduce the risk of the arc extinguishing current discharging the power supply of the mechanical switch through the arc.

In the above embodiments, the position of the arc extinguishing electrode B1 relative to the contact A1 or the contact A2 can be adjusted (in principle, the arc extinguishing electrode B1 should be close to the contact connected to the load), in order to adjust the arc ignition effect, the arc extinguishing connected to the arc Electrode B1 can flexibly adopt any shape (such as needle shape, ring shape, strip shape, U shape, Y shape, flat shape, etc.), and can also be used with magnetic blowing arc extinguishing devices to realize the connection between the arc and the arc extinguishing electrode, such as a mechanical When the switch K adopts a bridge structure, a permanent magnet can be placed at the end where the arc extinguishing electrode B1 is connected, so that the second arc can be connected to the arc extinguishing electrode B1 more quickly. The magnetic blowing arc design has a smaller magnetic blowing force on the first arc than on the second arc, which is beneficial to reduce the impact of the first arc on the electrical life of the mechanical switch.

In the above embodiment, the mechanical switch K can be a relay, or a contactor, or a circuit breaker, or an isolating switch, or a manual switch, and the mechanical switch can be a non-sealed (non-air-filled, non-vacuum) switch;

The mechanical switch K can adopt single-breakpoint or double-breakpoint structure as required;

The mechanical switch can be a mechanical switch that does not have the operating current (or voltage) to break or remove the original arc extinguishing grid of the mechanical switch, so as to reduce cost, volume and product weight.

In the above embodiment, when a capacitor is used to provide the arc extinguishing electrode with the arc extinguishing electrode, when it is detected that the arc is connected to the arc extinguishing electrode, it is preferable to provide the arc extinguishing current with a delay, because the contact surface between the initial arc and the arc extinguishing electrode is relatively small , The output current of the capacitor has a slow rise rate, and the output arc extinguishing current is small;

In the above embodiment, the voltage of the current source of the arc extinguishing current connected to the arc extinguishing electrode may be greater than the working voltage of the load connected to the mechanical switch.

In the above embodiments, the arc extinguishing electrode can also be used as a detection electrode for the leakage current of the mechanical switch (between A1 and B1, between A2 and B1).

The arc extinguishing device of the present invention can be used for mechanical switches in vehicles, or aviation, or ships, or new energy, and automatic control;

In the present invention, the load and power supply connected by the mechanical switch are defined as references to each other. When the power supply is defined as a load, the load is defined as a power supply. The loads connected by each mechanical switch can be a common load or independent loads. , The power supply connected to each mechanical switch can share one power supply, or it can be an independent power supply.

In summary, the present invention uses an arc extinguishing electrode to establish an electrical connection with the mechanical switch contact point, and has the following advantages:

1. Simple, no leakage current, high withstand voltage;

2. The current source for arc extinguishing is well isolated from the load, and the safety is high;

3. A mechanical switch needs only one arc extinguishing electrode (that is, an arc connection point) to achieve arc extinguishing, which is beneficial to adjust the position of the arc extinguishing electrode relative to the two contacts of the mechanical switch to achieve the best arc extinguishing effect, and It has little effect on the original electrical performance (arc extinguishing performance) of the mechanical switch and is easy to implement;

4. When a network with multiple mechanical switches shares a current source, there is no need for a controllable switch to switch, the circuit is simple, the isolation is good, and the cost is low.

Claims

An arc extinguishing device, which is characterized in that it includes an arc extinguishing electrode. During the breaking process of a mechanical switch that requires arc extinguishing, the arc between the contacts of the mechanical switch is connected to the arc extinguishing electrode, and the extinguishing electrode is The arc electrode is used to input the current used to extinguish the arc.
The arc extinguishing device according to claim 1, wherein the arc includes a front arc that is extinguished first and a rear arc that is extinguished later, and the length of the front arc is greater than the length of the rear arc.
The arc extinguishing device according to claim 1, characterized in that: the mechanical switch has a single break point structure, and when the mechanical switch is off, the distance between the arc extinguishing electrode and the movable contact is greater than that of the movable contact. The distance between the arc extinguishing electrode and the static contact.
The arc extinguishing device according to claim 1, characterized in that: the number of mechanical switches required to extinguish the arc is at least two, the arc extinguishing electrodes connected to each of the arcs are the same node, and the node is used to input the The current; or also includes an uncontrollable device, each of the arc extinguishing electrodes is connected through the uncontrollable device, the uncontrollable device adopts a common anode or a common cathode connection, the node of the common anode or the The node of the common cathode is used to input the current.
The arc extinguishing device according to claim 1, wherein the arc extinguishing electrode serves as a detection electrode for the leakage current of the mechanical switch.
The arc extinguishing device according to claim 1, wherein the mechanical switch includes a contact bridge, a first contact, and a second contact, and the arc includes the contact bridge and the first contact. The first arc and the second arc formed by the contact bridge and the second contact. During the breaking process of the mechanical switch, the second arc is connected to the arc extinguishing electrode, and when the arc extinguishing electrode is extinguished When the arc fails, an arc extinguishing piece is used to extinguish the first arc.
The arc extinguishing device according to any one of claims 1 to 6, characterized in that it further comprises a current source for supplying the current, the current source comprising a first switch, a control unit, and the control of the first switch The signal is provided by the control unit, and a power source provides the current through the first switch.
The arc extinguishing device according to claim 7, wherein the power source is a power source connected to the mechanical switch.
The arc extinguishing device according to claim 7, wherein the first switch is a fully-controlled semiconductor switch, or a half-controlled semiconductor switch, or a mechanical switch.
The arc extinguishing device according to claim 7, wherein the control unit is used to detect the voltage or current of the arc extinguishing electrode, or the control unit is used to detect the voltage or current of the power supply.