Natural state self-generation mutual inductance direct current arc extinguishing device and arc extinguishing method

Abstract

The invention relates to a natural state self-generated mutual inductance direct current arc extinguishing device and arc extinguishing method. The device comprises a static contact, a moving contact, a self-generated mutual inductance generator, a charge guider, an insulating shell and a charge absorption device. The static contact is arranged above the insulating shell, the moving contact is arranged in the insulating shell, and the self-generation mutual inductance generator is installed in an arc area, connected with the charge absorption device through a wire and used for collecting charges generated when the static contact and the moving contact are separated and combined and discharging the charges to the charge absorption device to be absorbed. The charge guider guides irregularly moving charges to the self-generated mutual inductance generator. According to the invention, the arc can be effectively extinguished under the natural state condition of direct current high voltage and large current, and the problems of safety, service life, power and environmental protection in the prior art are solved especially in the new energy field of battery automobiles, charging piles and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of natural state self-generated mutual inductance direct current arc extinguishing, and in particular relates to a direct current circuit breaker and a direct current relay arc extinguishing method. Background Art

[0002] The existing arc extinguishing methods of DC circuit breakers and DC relays mainly include: low temperature cooling liquid arc extinguishing, electric field blowing arc extinguishing, magnetic blowing arc extinguishing, vacuum or insulating gas filling arc extinguishing, contacts of different materials, arc extinguishing chambers of different shapes, etc. The existing arc extinguishing methods of DC circuit breakers and DC relays require vacuum or insulating gas filling to control the arcing time under high voltage and high current conditions.

[0003] For example, existing battery cars and charging piles require vacuum magnetic blown DC relays to cut off power supply for high voltage and high current. Affected by vibration, differences in expansion coefficients and other factors, vacuum devices are prone to leakage, and relays have a short service life. When the line is overloaded, the arcing time is long, and the temperature is high, it is very easy to burn or even explode. Therefore, it is necessary to solve the problem of reliably cutting off arcing under high voltage and high current conditions. Especially in the field of battery cars and charging piles, it is necessary to solve the technical method of reliably cutting off arcing under natural conditions.

[0004] The purpose of the present invention is to discharge the arc generated when the static contact and the moving contact are separated and combined, and the electric charges that move irregularly, to the charge absorption device in a natural state without an insulating gas high-pressure tank, so as to ensure that the residual charge in the arc zone is lower than the air breakdown voltage value.

[0005] The natural state self-generated mutual inductance DC arc extinguishing method can be applied to high voltage and ultra-high voltage DC circuit breakers. It only requires placing the static contact, the moving contact, the self-generated mutual inductance generator and other components in a vacuum environment. The method can reduce the circuit breaker's requirements for vacuum pressure and high-voltage tanks, and improve the reliability and power of the DC circuit breaker.

[0006] The safety issues, short life, low power and environmental protection problems existing in the original method have been solved.

[0007] After searching, the prior art closest to the present invention is patent application number 202311415413.1 applied by Tsinghua University, which is a mechanical switch arc extinguishing circuit, arc extinguishing chamber and method based on an electric field arc blowing device, specifically: the arc extinguishing circuit includes an arc striking conductor and an arc striking branch, wherein the arc striking branch is used to generate an electric field between the contacts of the mechanical switch and the arc striking conductor to drive the arc to move, wherein the contacts include a moving contact and a static contact; the arc striking conductor is used to connect with the driven arc; wherein the arc striking branch is also used to drive current transfer after the arc striking conductor is connected with the driven arc, so that the power electronic switch carries the fault current and completes the disconnection.

[0008] The main distinguishing technical features of the present invention and the comparative document 202311415413.1 are:

[0009] The direct discharge arc extinguishing method of the self-generated mutual inductance generator and the charge absorption device in the present invention is significantly different from the method in the comparative document that the electric field drives the arc to move and uses the capacitor branch to inject current into the power electronic switch branch. In the present invention, in a natural state, the self-generated mutual inductance generator directly discharges the charge in the arc area to the capacitor or the earth, without adding an auxiliary power supply, to ensure that the residual charge in the arc area is lower than the air breakdown voltage value, thereby achieving arc extinguishing. The electric field arc blowing device in the comparative document, when the contact separation generates an arc, guides the arc to the arc-starting conductor through the electric field, and also requires the traditional technology with the biggest defect: the insulating gas high-pressure tank, and finally transfers the current to the power electronic switch to achieve the interruption of the fault current, and an auxiliary power supply is required. The core difference between the two lies in the arc extinguishing mechanism and the current transfer path. These differences show that although both are aimed at solving the problem of arc extinguishing of DC arc, the technical means and solutions adopted are fundamentally different. The present invention completely extinguishes the arc by direct discharge of charge under natural conditions, while the comparative documents focus on utilizing electric fields, requiring insulating gas high-pressure tanks with serious weaknesses, separate external power supplies and capacitor branches to indirectly promote current transfer in order to achieve the arc extinguishing effect. Summary of the invention

[0010] The present invention aims to solve the problems existing in the above prior art. A natural state self-generated mutual inductance DC arc extinguishing device and method are proposed. The technical solution of the present invention is as follows:

[0011] A natural state self-generated mutual inductance DC arc extinguishing device comprises: a static contact, a moving contact, a self-generated mutual inductance generator, an insulating shell and a charge absorption device; the static contact is arranged above the insulating shell, the moving contact is arranged inside the insulating shell, the self-generated mutual inductance generator is installed in the arc zone and connected to the charge absorption device via a wire, and is used for collecting the charge generated when the static contact and the moving contact are separated and combined, and discharging the charge to the charge absorption device for absorption.

[0012] Furthermore, it also includes a charge director, which guides the charge to the self-generated mutual inductance generator.

[0013] Furthermore, the charge guide is composed of a magnetic material and an insulating material, the magnetic material is wrapped inside the insulating material, the charge guide is installed in the arc zone, the charge guide is installed on the self-generated mutual inductance generator, the magnetic material generates an Ampere force in the magnetic field, and under the combined action of the Ampere force in the magnetic field and the resistance of the insulating material, the irregularly moving charges in the shell cavity are guided to the self-generated mutual inductance generator.

[0014] Furthermore, the self-generated mutual inductance generator is a conductor chemical composite material, and one or more can be provided and interconnected and conductive.

[0015] Furthermore, the charge absorbing device is a capacitor or the earth, which can provide a discharge path for the charge in a natural state.

[0016] Furthermore, the self-generated mutual inductance generator is insulated from the moving contact and the static contact; and the charge director is insulated from the moving contact and the static contact.

[0017] Furthermore, it also includes an auxiliary arc extinguishing circuit, which includes a diode for promoting the intersection of positive and negative charges in the arc zone and accelerating the extinction of the arc.

[0018] Furthermore, the diode is used to control the charge discharge direction and prevent reverse current.

[0019] Furthermore, the structure of the contact bridge driving part includes electromagnetic or pneumatic or stored energy release, which is used to realize the separation and connection of the upper contact and the lower contact.

[0020] Furthermore, it also includes a discharge branch, which uses a resistor or a high-resistance reactance to automatically discharge the capacitor in preparation for the next arc extinguishing.

[0021] An arc extinguishing method using any of the above devices, comprising the following steps:

[0022] Arc generation: When the static contact and the moving contact are separated, due to the potential difference between the two, the free charges in the air are accelerated and collided again in the gap between the moving contact and the static contact, breaking through the air to form an arc;

[0023] Charge collection: The self-generated mutual inductance generator is designed as a conductive composite material located in the arc formation area and is insulated from the moving contact and the static contact; the charge guide guides the charge to the self-generated mutual inductance generator; when the arc is formed, the self-generated mutual inductance generator can collect the charge in the arc instead of letting the arc continue to burn;

[0024] Charge discharge: The self-generated mutual inductance generator is connected to the charge absorption device through a wire; after the generated charge is collected, it is quickly discharged to the charge absorption device through the wire to reduce the charge amount in the arc zone;

[0025] Arc extinction: Once the charge is absorbed, the amount of charge in the arc zone will be lower than the breakdown voltage of the air, the arc will lose the energy to maintain its existence and eventually extinguish.

[0026] The advantages and beneficial effects of the present invention are as follows:

[0027] 1. Active collection and discharge of charge: Traditional arc extinguishing methods mostly rely on physical means (such as vacuum, gas arc blowing, magnetic blowing, etc.) to shorten the arc burning time. The present invention actively collects arc charges through a self-generated mutual inductance generator, and then discharges the charges to a charge absorption device through a wire. This is an active charge management method, which is different from the passive physical arc extinguishing method.

[0028] 2. Improve arc extinguishing efficiency and reliability: By designing a specific self-generated mutual inductance generator device and a charge absorption device, the present invention can extinguish arcs faster and more effectively under high voltage and high current conditions, especially in new energy fields such as battery vehicles and charging piles, solving the safety, environmental protection, life and power problems in the prior art.

[0029] 3. Reduce the impact on the environment: Compared with arc extinguishing methods that rely on vacuum or specific gases, the present invention is in a purely natural state, reducing the stringent requirements for vacuum pressure and high-pressure tanks, so that reliable arc extinguishing can be achieved under natural conditions.

[0030] 4. Adaptability to different application scenarios: The flexible choice of charge absorption device (capacitor or ground) enables the present invention to adapt to different voltage levels and usage environments, and has wide applicability and high technical flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the contact bridge structure of a natural state self-generated mutual inductance DC arc extinguishing device, and the charge absorption device is a capacitor;

[0032] Figure 2 It is a schematic diagram of the contact bridge structure of the natural state self-generated mutual inductance DC arc extinguishing device, and the charge absorption device is the earth;

[0033] Figure 3 A schematic diagram of a single contact structure of a natural state self-generated mutual inductance DC arc extinguishing device, wherein the charge absorption device is a capacitor;

[0034] Figure 4 This is a schematic diagram of a single contact structure of a natural state self-generated mutual inductance DC arc extinguishing device, in which the charge absorption device is the earth.

[0035] Figure 5 A diagram showing one of the structural shapes of a self-generated mutual inductance generator;

[0036] Figure 6 A diagram showing one of the structural shapes for charge guidance;

[0037] Among them, 1. static contact 2. insulating shell 3. charge director 4. moving contact 5. self-generated mutual inductance generator 6. insulator 7. moving contact bridge 8. spring 9. core drive device 10. insulating lower end cover 11. ground wire connector 12. connecting wire 13. core. C. capacitor. DETAILED DESCRIPTION

[0038] The following will describe the technical solutions in the embodiments of the present invention in detail in conjunction with the accompanying drawings in the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention.

[0039] The technical solution of the present invention to solve the above technical problems is:

[0040] 1. Attachment Figure 1 The schematic diagram of the touch bridge structure of the DC self-generated mutual inductance arc extinguishing method, in which the charge absorption device is a capacitor; according to the above principle, the attached Figure 1 It can be seen that the charge absorption device is a capacitor. When a DC current flows through the moving contact and the static contact, the moving contact is disconnected under the action of mechanical force. The charge generated between the moving contact and the static contact is guided by the charge guide to the self-generated mutual inductance generator, and connected to one pole of the capacitor through a wire. The other pole of the capacitor is connected to the static contact through a wire to form a loop, and the charge is discharged to the capacitor, thereby extinguishing the arc. The resistor R automatically discharges the capacitor to prepare for the next arc extinguishing. It should be noted that, in this embodiment, the other pole of the capacitor can also be connected to the moving contact through a wire to form a loop, and the charge is discharged to the capacitor, and no more drawings are drawn here for example.

[0041] 2. Attachment Figure 2 The schematic diagram of the contact bridge structure of the DC self-generated mutual inductance arc extinguishing method, in which the charge absorption device is the earth; according to the above principle, the attached Figure 2 It can be seen that the charge absorption device is the earth. When a DC current flows through the moving contact and the static contact, the moving contact opens and closes under the action of mechanical force. The charge generated between the moving contact and the static contact is guided to the self-generated mutual inductance generator by the charge guide. The self-generated mutual inductance generator is connected to the earth with a wire, and the charge is discharged to the earth. The earth absorbs the charge and the arc is extinguished.

[0042] 3. Attachment Figure 3 The schematic diagram of the single contact structure of the DC self-generated mutual inductance arc extinguishing method, in which the charge absorption device is a capacitor; according to the above principle, the attached Figure 3 It can be seen that the moving contact and the static contact are single contact structures. When the moving contact is disconnected under the action of mechanical force, the charge generated between the moving contact and the static contact is guided by the charge guide to the self-generated mutual inductance generator, and the self-generated mutual inductance generator is connected to one pole of the capacitor by a wire, and the other pole of the capacitor is connected to the static contact through a wire to form a loop; in another way, the other pole of the capacitor is connected to the diode and the moving contact through a wire to form a loop, and the charge is discharged to the capacitor, thereby extinguishing the arc. The resistor R automatically discharges the capacitor to prepare for the next arc extinguishing, and the moving contact is the positive pole.

[0043] 4. Attachment Figure 4This is a schematic diagram of the single contact structure of the DC self-generated mutual inductance arc extinguishing method, in which the charge absorption device is the earth; according to the above principle, the attached Figure 4 It can be seen that the charge absorption device is the earth. When a DC current flows through the moving contact and the static contact, the moving contact opens and closes under the action of mechanical force. The charge generated between the moving contact and the static contact is guided to the self-generated mutual inductance generator by the charge guide. The self-generated mutual inductance generator is connected to the earth with a wire, and the charge is discharged to the earth. The earth absorbs the charge and the arc is extinguished.

[0044] It can be seen from the embodiments combined with the above that, firstly, no matter whether the self-generated mutual inductance generator is arranged around the static contact or on the moving contact bridge, its arc extinguishing principle is the same; secondly, the other pole of the capacitor can be connected to the moving contact or the static contact to form a loop to discharge the charge to the capacitor; thirdly, the diode is used to control the direction of charge discharge and prevent reverse current, and is designed according to requirements, so it will not be described one by one here.

[0045] Beneficial Effects

[0046] In summary, the use of this method to design a DC circuit breaker can reduce the circuit breaker's stringent requirements for vacuum pressure and arc-extinguishing gas, making it cheaper to use in the field of high-voltage DC circuit breakers, with higher high-voltage indicators for DC power and better technical reliability; the use of this method to design a DC relay can achieve load disconnection in a natural state without insulating gas or high-voltage tanks, and can be widely used in new energy vehicles, charging piles, photovoltaics, ships, aviation, communications, ultra-high voltage and other fields.

[0047] The problems of safety, environmental protection, short life and low power in the existing arc extinguishing methods are solved more comprehensively.

[0048] The natural state described in the present invention is: atmospheric pressure at an altitude of 0-6000 meters, and relative air humidity of 0-100%.

[0049]

[0050] Since the maximum DC voltage of the detection device is only 1KV and the current is only 500A, the natural state described in the present invention refers to the natural state high voltage DC arc extinguishing under this condition, and the air breakdown voltage is not reached under this condition. However, the breakdown voltage of this technology is unknown due to the limitation of the detection device. The following is a comparison of the technical parameters under the natural state with the prior art:

[0051]

[0052]

[0053] The difference between the principle of the self-generated mutual inductance generator and the principle of the traditional mutual inductance generator is that the power supply automatically discharges the negative charge on the mutual inductance of the mutual inductance generator, so as not to break down the air and form a conduction arc. Whether the self-generated mutual inductance generator is installed on the static contact or the moving contact, the self-generated mutual inductance generator will only induct the positive charge, and the negative charge in the shell cavity will attract each other and neutralize the discharge under the combined action of the force between the charges and the electric field; the traditional mutual inductance generator is a mutual inductance electromotive force, and the traditional theory cannot explain why this technology only inducts positive charges. Therefore, the following can only prove the principle of this technology by using the coulombmeter test results without breaking down the air and forming a conduction arc. The coulombmeter detects positive charge and electricity as shown in the following table:

[0054]

[0055] One of the structures of the self-generated mutual inductance generator is as follows Figure 5 As shown:

[0056] The structure of the self-generated mutual inductance generator is as follows: it is punched from 70--90% copper powder, 5--15% iron powder, and 5--15% ferric hydroxide.

[0057] Charge director principle: Figure 6 In the figure, the charge guide is composed of a magnetic material 6-1 (providing an Ampere force of a magnetic field) and an insulating material 6-2 (resistance of a resistor plate). The magnetic material 6-1 is wrapped inside the insulating material 6-2. The charge guide is installed in the arc zone. The magnetic material 6-1 generates an Ampere force of a magnetic field. Under the combined action of the Ampere force of the magnetic field and the resistance of the resistor plate of the insulating material 6-2, the irregularly moving negative charges in the shell cavity are guided to the self-generated mutual inductance generator to avoid secondary impact.

[0058] According to the above principle, the self-generated mutual inductance generator uses the mutual inductance positive charge generated by the self-generated mutual inductance generator to discharge the charge generated between the moving contact and the static contact to the charge absorption device at the speed of light. Because there are random charges hitting the air, it is necessary to use a charge guide fixed on the self-generated mutual inductance generator to guide as many charges as possible to the self-generated mutual inductance generator, so that the amount of discharged charge is sufficient to ensure that the remaining charge does not reach the air breakdown voltage value, the arc burning time is close to zero, and the arc is extinguished fundamentally. Due to the small number of charge collisions, the lower heat temperature generated can slow down the contact erosion speed. Regardless of whether the moving contact and the static contact remain in the open or closed state, or in the open or closed movement process, the self-generated mutual inductance generator always has mutual inductance to ensure that the arc energy can be discharged at any time.

[0059] The strength of the mutual inductance of the self-generated mutual inductance generator is determined by two factors:

[0060] 1. Cut and connect the power of the DC power supply: large power means strong mutual inductance, small power means weak mutual inductance.

[0061] 2. The distance between upper and lower contacts: the smaller the distance, the stronger the mutual inductance; the larger the distance, the weaker the mutual inductance.

[0062] The strength of the mutual inductance of the above two factors corresponds exactly to the strength of the arc drawing.

[0063] The DC self-generated mutual inductance arc extinguishing method, the charge absorption device referred to in the technical solution can be: a capacitor or the earth, and can be selected according to the environment where the DC circuit breaker and the relay are located.

[0064] There are two design schemes for the application of natural state self-generated mutual inductance arc extinguishing in DC circuit breakers and relays:

[0065] Solution A: When the self-generated mutual inductance generator is installed around the moving contact, the charge guide is installed on the self-generated mutual inductance generator, and both are located in the arc zone.

[0066] Solution B: When the self-generated mutual inductance generator is installed around the static contact, the charge guide is installed on the self-generated mutual inductance generator, and both are located in the arc zone.

[0067] In actual implementation, Scheme A is preferred, and the following examples are described based on Scheme A. Since the principle of Scheme B is the same as that of Scheme A, those skilled in the art can implement Scheme B according to the Scheme A example, so it will not be described in detail.

[0068] The self-generated mutual inductance generator and the charge guide are arranged on the contact bridge, and the self-generated mutual inductance generator can be installed around the moving contact bridge and the static contact, depending on the technical requirements.

[0069] The charge absorption device described in the natural state self-generated mutual inductance DC arc extinguishing method can be: a capacitor; the earth. An optional scheme can be selected according to design requirements. The capacitance of the capacitor is relatively large, and it is based on being able to completely absorb the arc energy.

[0070] The structure of the contact bridge driving part of the DC self-generated mutual inductance arc extinguishing method can be designed according to needs, such as electromagnetic, pneumatic, energy storage release, etc., which belongs to the well-known technology and will not be described here.

[0071] 1. Interdisciplinary thinking: Introducing the concept of self-generated mutual inductance generator into the field of arc extinguishing requires interdisciplinary thinking, that is, integrating and applying knowledge from fields such as power electronics, materials science and arc physics, which has no precedent in traditional power equipment design.

[0072] 2. Innovative charge handling method: Actively collect charge through self-generated mutual inductance generator and design special charge absorption device to handle charge. This requires a deep understanding of the nature of arc and precise control of charge behavior, which is a breakthrough in DC arc extinguishing technology.

[0073] 3. Challenges in practical applications: In terms of design and implementation, it is necessary to solve problems such as the shape design of the self-generated mutual inductance generator and the relative position to the contacts. At the same time, the capacity and efficiency of the charge absorption device must also be considered. These require a lot of experiments and theoretical analysis. Therefore, it is challenging to significantly improve them in practical applications.

[0074] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0075] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0076] The above embodiments should be understood to be only used to illustrate the present invention and not to limit the protection scope of the present invention. After reading the contents of the present invention, technicians can make various changes or modifications to the present invention, and these equivalent changes and modifications also fall within the scope defined by the claims of the present invention.

Claims

1. A natural state self-generated mutual inductance DC arc extinguishing device, characterized in that: include: Static contact, moving contact, self-generated mutual inductance generator, insulating shell and charge absorption device; the static contact is arranged above the insulating shell, the moving contact is arranged inside the insulating shell, the self-generated mutual inductance generator is installed in the arc zone and connected to the charge absorption device through a wire, and is used to collect the charge generated when the static contact and the moving contact are separated and combined, and discharge the charge to the charge absorption device for absorption.

2. The natural state self-generated mutual inductance DC arc extinguishing device according to claim 1 is characterized in that: Also included is a charge director that directs the charge to the self-generated mutual inductance generator.

3. The natural state self-generated mutual inductance DC arc extinguishing device according to claim 2 is characterized in that: The charge guide is composed of a magnetic material and an insulating material. The magnetic material is wrapped inside the insulating material. The charge guide is installed in the arc zone. The charge guide is installed on the self-generated mutual inductance generator. The magnetic material generates an Ampere force in the magnetic field. Under the combined action of the Ampere force in the magnetic field and the resistance of the insulating material, the irregularly moving charges in the shell cavity are guided to the self-generated mutual inductance generator.

4. The natural state self-generated mutual inductance DC arc extinguishing device according to claim 1, characterized in that: The self-generated mutual inductance generator adopts a conductor chemical composite material, and one or more can be provided, interconnected and conductive.

5. The natural state self-generated mutual inductance DC arc extinguishing device according to claim 1, characterized in that: The charge absorbing device is a capacitor or the earth, or can be a capacitor and the earth compatible at the same time, providing a discharge path for the charge in a natural state.

6. The natural state self-generated mutual inductance DC arc extinguishing device according to claim 1, characterized in that: The self-generated mutual inductance generator is insulated from the moving contact and the static contact; the charge guide is insulated from the moving contact and the static contact.

7. An arc extinguishing method using the device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Arc generation: When the static contact and the moving contact are separated, due to the potential difference between the two, the free charges in the air are accelerated and collided again in the gap between the moving contact and the static contact, breaking through the air to form an arc; Charge collection: The self-generated mutual inductance generator is designed as a conductive composite material located in the arc formation area and is insulated from the moving contact and the static contact; the charge guide guides the charge to the self-generated mutual inductance generator; when the arc is formed, the self-generated mutual inductance generator can collect the charge in the arc instead of letting the arc continue to burn; Charge discharge: The self-generated mutual inductance generator is connected to the charge absorption device through a wire; after the generated charge is collected, it is quickly discharged to the charge absorption device through the wire to reduce the charge amount in the arc zone; Arc extinction: Once the charge is absorbed, the amount of charge in the arc zone will be lower than the breakdown voltage of the air, the arc will lose the energy to maintain its existence and eventually extinguish.

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