Arc extinguishing device

Abstract

The present invention relates to an arc extinguishing device, in particular to an arc extinguishing device suitable for arc extinguishing of a bridge structure switch, comprising a first device, the main circuit electrode of the first device comprising a first electrode and a second electrode, the switch required to extinguish the arc comprising a first end, a second end, and a touch bridge, the first electrode and the second electrode are respectively used to connect to the first end and the second end, and further comprising a capacitor and a first voltage detection switch, the first voltage detection switch and the third electrode and the second electrode of the first device form a first series circuit, the touch bridge and the second end form a second series circuit, the first series circuit is connected in parallel with the second series circuit, and the capacitor is connected in parallel with the second end series circuit. The present invention has a reasonable design, high cost performance, simple circuit, good arc extinguishing effect, and high reliability.

Description

Technical Field

[0001] The invention relates to an arc extinguishing device, in particular to an arc extinguishing device suitable for arc extinguishing of a bridge structure (connection) switch, which has high cost performance, simple circuit, good arc extinguishing effect and high reliability. Background Art

[0002] There are more and more DC usage scenarios, but DC arc extinguishing has always been a difficulty. Summary of the invention

[0003] The purpose of the present invention is to solve the problems described in the background art and to provide an arc extinguishing device which has high cost performance, simple circuit, good arc extinguishing effect, high reliability and is suitable for bridge structure switches.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] like Figure 1 As shown, an arc extinguishing device includes a first device QA, the main circuit electrode of the first device QA includes a first electrode 1 and a second electrode 2, the switch S1 required to extinguish the arc includes a first end N1 (i.e., a node where the first static contact of the switch S1 is located), a second end N2 (i.e., a node where the second static contact of the switch S1 is located), and a contact bridge N3, the first electrode 1 and the second electrode 2 are respectively used to connect to the first end N1 and the second end N2, and also includes a capacitor C1 and a first voltage detection switch VT1, the first voltage detection switch VT1 and the third electrode 3 and the second electrode 2 of the first device QA form a first series circuit, the contact bridge N3 and the second end N2 form a second series circuit, the first series circuit is connected in parallel with the second series circuit, and the capacitor C1 is connected in parallel with the second series circuit.

[0006] Working principle: Figure 1 As shown, when the contact bridge N3 is disconnected relative to the second end N2, the potential difference between the contact bridge N3 and the second end N2 quickly charges the capacitor C1 (it can also realize arc extinguishing of the second series circuit). When the voltage of the capacitor C1 (the second series circuit) (the voltage between the contact bridge and the third electrode) reaches the turn-on voltage of the first voltage detection switch VT1, the first voltage detection switch VT1 is turned on, and the voltage of the capacitor C1 drives the first device QA to turn on, realizing arc extinguishing between the first end N1 and the second end N2. Then the capacitor C1 cannot obtain continuous charging power, the first device QA is turned off, and the working process is completed.

[0007] The invention has reasonable design, high cost performance, simple circuit, good arc extinguishing effect and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is the principle diagram of the arc extinguishing device of the present invention.

[0009] Figure 2 It is a principle diagram of an embodiment of the arc extinguishing device of the present invention.

[0010] Figure 3 It is a schematic diagram of the first voltage detection switch of the arc extinguishing device of the present invention.

[0011] Figure 4 It is a schematic diagram of the second voltage detection switch of the arc extinguishing device of the present invention.

[0012] Figure 5 It is a schematic diagram of the conduction waveforms of the first detection switch and the second voltage detection switch of the arc extinguishing device of the present invention.

[0013] Figure 6 It is a schematic diagram of the switch required for arc extinguishing of the arc extinguishing device of the present invention. DETAILED DESCRIPTION

[0014] Embodiments of the present invention:

[0015] like Figure 2 As shown, an arc extinguishing device includes a first device QA (a fully controlled device, preferably a field effect tube or an IGBT), the main circuit electrodes of the first device QA include a first electrode 1 (drain, or collector), a second electrode 2 (source, or emitter), a capacitor C1, a first resistor R1, a second resistor R2, a first voltage detection switch VT1, a second voltage detection switch VT2, and a voltage limiting device RV (Zener device). The switch S1 required for arc extinguishing includes a first terminal N1, a second terminal N2, and a contact bridge N3. The first electrode 1 and the second electrode 2 are used to connect to the first terminal N1 and the second terminal N2 respectively. The switch S1 is a bridge structure (two single power-off switches can be connected in series to form a bridge structure switch). The first resistor R1, the first voltage detection switch VT1, the third electrode 3 (gate) of the first device QA, and the second electrode 2 form a first series circuit. The contact bridge N3 and the second terminal N2 form a second series circuit. The first series circuit is connected in parallel with the second series circuit. The capacitor C1 and the voltage limiting device RV are connected in parallel with the second series circuit. The first voltage detection switch VT1 is used to detect the voltage of the capacitor (the second series circuit, between the third electrode and the capacitor C1 or the contact bridge N3). The first voltage detection switch VT1 is turned on when the voltage of the capacitor C1 is greater than the voltage required to drive the first device QA to saturate and turn on. The second voltage detection switch VT2 (such as Figure 4 As shown, it is composed of a resistor, a capacitor, a triode, a diode, and a Zener device, and other similar circuits can also be used) and is connected to the first series circuit. When the second voltage detection switch VT2 detects that the voltage is less than the design value of the second voltage detection switch VT2, it is turned on to discharge the capacitor C1. The turn-on voltage of the second voltage detection switch VT2 is less than the turn-on voltage of the first voltage detection switch VT1 (such as Figure 5As shown, it is a schematic diagram of the driving voltage waveform between the third electrode and the second electrode); the second voltage detection switch VT2 is a delay switch; the turn-on voltage of the first voltage detection switch VT1 is greater than the voltage required to drive the first device QA to saturation conduction; the second electrode 2, the third electrode 3 and the second resistor R2 are connected in parallel.

[0016] The first voltage detection switch VT1 is a half-controlled switch (trigger switch), which is composed of a first voltage stabilizing device Z1 (for adjusting the start-up voltage), a half-controlled semiconductor switch (preferably a thyristor equivalent circuit composed of triodes, which can be replaced by a thyristor), the half-controlled semiconductor switch includes a first triode Q1 (N type) and a second triode Q2 (P type), the base of the first triode Q1 is connected to the collector of the second triode Q2, the base of the second triode Q2 is connected to the collector of the first triode Q1, and the two ends of the first voltage stabilizing device Z1 are respectively connected to the emitter and collector of the first triode Q1 (such as Figure 3 As shown), or the two ends of the first voltage stabilizing device Z1 are connected to the emitter and collector of the second triode Q2 respectively (as shown Figure 2 As shown), the third resistor R3 and the fourth resistor R4 respectively connected to the transistors Q1 and Q2 are used to improve the circuit stability; the first voltage detection switch VT1 can also adopt a trigger diode (and its equivalent electrical characteristic device, also defined as a half-controlled switch), or other equivalent circuits.

[0017] Working principle: When the contact bridges N3 and N2 are disconnected, the contact bridge N3 quickly charges the capacitor C1 and extinguishes the arc in the second series circuit (i.e., extinguishes the arc between N3 and N2). When the voltage of the capacitor C1 reaches the turn-on voltage of the first voltage detection switch VT1, the first voltage detection switch VT1 is turned on, and the voltage of the capacitor C1 drives the first device QA to saturate and conduct, thereby extinguishing the arc between the first terminal N1 and the second terminal N2. The capacitor C1 is turned on when the voltage reaches the voltage required to drive the first device QA to saturate and conduct; the first voltage detection switch VT1 is turned on when it detects that the voltage provided by the capacitor C1 is less than the design value of the second voltage detection switch VT2, thereby realizing rapid cutoff of the first device QA.

[0018] The switch required for arc extinguishing can be connected into a bridge structure by two single-break switches (such as Figure 6 As shown in the figure), the common node of two single-breakpoint switches is also defined as a touch bridge.

[0019] The above embodiment may further include a diode, through which the contact bridge N3 charges the capacitor C1.

[0020] The voltage limiting device RV in the above embodiment can be selected as a varistor, or a voltage stabilizing diode, or a transient suppression diode, and related equivalent devices; the withstand voltage value (turn-on voltage) of the voltage limiting device RV can be selected to be smaller than the system operating voltage of the switch (for example, a system operating voltage of hundreds of volts can directly select a voltage limiting device with a turn-on voltage of 10 volts to 35 volts, and the withstand voltage value of the voltage limiting device RV is preferably smaller than the withstand voltage value between the third electrode and the second electrode), and the withstand voltage value of the matching capacitor C1 and the first voltage detection switch VT1 can be selected to be smaller than the system operating voltage of the switch S1, which is beneficial to significantly reduce the cost and volume of the arc extinguishing device of the present invention.

[0021] The above embodiments, such as Figure 5 As shown, the values ​​of VT1 and VT2 can be adjusted by Z1 and Z2, and the pulse width of the pulse voltage driving QA can be flexibly adjusted by the relevant parameters of Z1, Z2, R1, R2, C1, and RV, which has the advantage of stable pulse signal.

[0022] In the above embodiments, when the first voltage detection switch adopts a voltage-controlled device (field effect transistor, IGBT) driver IC, it integrates the second voltage detection switch (function) and has the advantage of being smaller in size.

[0023] The present invention utilizes the rapid charging of capacitor C1 to achieve arc breaking between N3 and N2, or reduce the arc. The potential difference between N3 and N2 is rapidly increased, which can further accelerate the charging speed of the capacitor. When the first voltage detection switch detects that the capacitor voltage meets the requirements for driving the first device QA to be saturated and turned on, the first device QA is driven to be saturated and turned on quickly. The characteristic of the first voltage detection switch as a half-controlled switch is utilized to meet the signal pulse width for driving the first device QA, prevent the circuit from oscillating, and reduce the risk of damage to the arc extinguishing device.

[0024] The invention has reasonable design, high cost performance, simple circuit, good arc extinguishing effect and high reliability.

Claims

1. An arc extinguishing device, comprising a fully controlled device, wherein the main circuit electrode of the fully controlled device comprises a first electrode and a second electrode, the switch required to extinguish the arc comprises a first end, a second end, and a contact bridge, the first electrode and the second electrode are respectively used to connect to the first end and the second end, wherein: It also includes a capacitor and a first voltage detection switch. The first voltage detection switch and the third electrode and the second electrode of the fully-controlled device form a first series circuit. The contact bridge and the second end form a second series circuit. The first series circuit is connected in parallel with the second series circuit, and the capacitor is connected in parallel with the second series circuit.

2. The arc extinguishing device according to claim 1 is characterized in that: The first voltage detection switch is used to detect the voltage of the capacitor or the second series circuit, and the first voltage detection switch is turned on under the condition that the voltage of the capacitor is greater than the voltage required to drive the fully-controlled device to saturate and turn on.

3. The arc extinguishing device according to claim 1, characterized in that: It also includes a second voltage detection switch connected to the first series circuit, which is turned on to discharge the capacitor when the second voltage detection switch detects that the voltage is less than the design value of the second voltage detection switch, and the turn-on voltage of the second voltage detection switch is less than the turn-on voltage of the first voltage detection switch.

4. The arc extinguishing device according to claim 3 is characterized in that: The second voltage detection switch is a time-delay switch.

5. The arc extinguishing device according to claim 1, characterized in that: The device further comprises a diode, and the contact bridge charges the capacitor through the diode.

6. The arc extinguishing device according to claim 1, characterized in that: The first voltage detection switch is a voltage-controlled device driver IC.

7. The arc extinguishing device according to claim 1, characterized in that: It also includes a voltage limiting device, which is connected in parallel with the second series circuit.

8. The arc extinguishing device according to claim 7, characterized in that: The withstand voltage of the voltage limiting device is less than the system operating voltage of the switch.

9. The arc extinguishing device according to claim 7, characterized in that: The withstand voltage of the capacitor is less than the system operating voltage of the switch.

10. The arc extinguishing device according to claim 7, characterized in that: The withstand voltage of the first voltage detection switch is less than the system operating voltage of the switch.

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