A method and device for aging a vacuum interrupter

Abstract

The present application relates to the technical field of vacuum interrupter aging, and particularly relates to a vacuum interrupter aging method and device, which comprises a high-voltage trigger assembly, a low-voltage trigger assembly, a vacuum interrupter, an arc current detection unit and a high-voltage diode; the high-voltage trigger assembly and the low-voltage trigger assembly are connected with the vacuum interrupter and are connected in parallel; the high-voltage trigger assembly and the low-voltage trigger assembly are both provided with a charging device; the current direction of the high-voltage diode is the same as that in the low-voltage trigger assembly; the arc current detection unit controls the low-voltage trigger assembly to work after detecting the current. The method of the present application eliminates the free conductive particles in the vacuum interrupter and the burrs on the contact surface by sequentially applying a high-voltage electric field and aging the arc, and the high-temperature penetration of the aging arc releases the gas in the contact and absorbs the gas by the getter, thereby reducing the probability of reignition when the capacity is switched and the aging cost.

Description

Technical Field

[0001] This invention relates to the field of vacuum interrupter aging technology, specifically to a vacuum interrupter aging method and apparatus. Background Technology

[0002] As a core component of vacuum switchgear, the vacuum interrupter has a decisive impact on the performance of vacuum switches. With the rapid expansion of the application scope and scale of vacuum switches in power systems, the requirements for vacuum interrupters are also constantly increasing. In terms of capacitive switching, national requirements for reducing the probability of reignition have made the aging of vacuum interrupters increasingly important.

[0003] There are three main reasons for reignition in vacuum interrupters during capacitive switching: a decrease in vacuum due to contact venting, excessively high local electric field strength caused by contact burrs, and free conductive particles inside the vacuum interrupter. The first two reasons for reignition can be significantly improved after traditional aging of the vacuum interrupter.

[0004] Traditional aging techniques for vacuum interrupters mainly consist of current aging and voltage aging, which are performed separately. This aging method is not very effective in eliminating free conductive particles inside the vacuum interrupter, so the probability of reignition remains relatively high during capacitive switching. To completely reduce the probability of reignition, the vacuum switch is typically sent to a specialized testing station for a certain number of high-voltage, high-current capacitive switching tests. This method has a significant aging effect but is very costly. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a vacuum interrupter aging method and apparatus that can eliminate the three factors that lead to reignition, especially the effective elimination of free conductive particles inside the vacuum interrupter, thereby reducing the probability of reignition and aging costs during capacitive switching.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for aging a vacuum interrupter, characterized by comprising the following steps:

[0007] S1: The transient current generated by the discharge of the high-voltage capacitor bank generates a high-voltage electric field in the vacuum interrupter chamber, while not generating an electric arc;

[0008] S2: A follow current arc is generated in the vacuum interrupter by reducing the resistance between the high-voltage capacitor and the vacuum interrupter.

[0009] S3: After detecting the arc current passing through the vacuum interrupter, the low-voltage capacitor bank discharges to generate a mature arc in the vacuum interrupter until the aging process ends.

[0010] Preferably, the absence of an electric arc in step S1 is achieved by setting an arc-suppressing resistor and an arc-extending resistor in series between the high-voltage capacitor and the vacuum interrupter to limit the current passing through the vacuum interrupter when it is closed to below the arc-starting current.

[0011] Preferably, in step S2, the generation of the follow current arc is achieved by retaining the arc-extending resistance through the shielding arc-extinguishing resistor to control the current passing through the vacuum arc-extinguishing chamber when it is closed to be above the arc-starting current.

[0012] Preferably, in step S3, an aging switch and a high-voltage diode are provided between the low-voltage capacitor bank and the vacuum interrupter. The aging switch is controlled by an arc current detection unit. After the arc current detection unit detects that an arc current is passing through the vacuum interrupter, it controls the aging switch to close, thereby connecting the low-voltage capacitor bank and the vacuum interrupter to generate an aging arc.

[0013] A aging device for a vacuum interrupter includes a high-voltage triggering component, a low-voltage triggering component, a vacuum interrupter, an arc current detection unit, and a high-voltage diode. Both the high-voltage and low-voltage triggering components are connected to the vacuum interrupter and are connected in parallel. Both the high-voltage and low-voltage triggering components are equipped with a charging device. The low-voltage triggering component further includes an aging switch, which is located between the charging device of the low-voltage triggering component and the vacuum interrupter.

[0014] The high-voltage diode is located between the high-voltage triggering component and the low-voltage triggering component, and the current direction of the high-voltage diode is the same as the current direction in the low-voltage triggering component; the arc current detection unit is located at the lower end of the vacuum interrupter, and the output terminal of the arc current detection unit is connected to the aging switch to control the discharge of the low-voltage triggering component.

[0015] Preferably, the high-voltage triggering component includes a high-voltage DC source, a high-voltage charging switch, a high-voltage capacitor bank, a bypass switch, an arc-suppressing resistor, and an arc-extending resistor; the positive terminal of the high-voltage capacitor bank and the bypass switch are both connected to the positive terminal of the high-voltage DC source through the high-voltage charging switch; the positive terminal of the high-voltage capacitor bank is connected to the upper end of the vacuum interrupter through the arc-suppressing resistor and the arc-extending resistor connected in series; the negative terminal of the high-voltage capacitor bank is connected to the lower end of the vacuum interrupter, and both are connected to the negative terminal of the high-voltage DC source; the bypass switch is connected in parallel with the arc-suppressing resistor and in series with the arc-extending resistor.

[0016] Preferably, the low-voltage triggering component includes a low-voltage DC source, a low-voltage charging switch, and a low-voltage capacitor bank; the positive terminal of the low-voltage capacitor bank is connected to the positive terminal of the high-voltage diode through a aging switch and to the positive terminal of the low-voltage DC source through the low-voltage charging switch; the negative terminal of the low-voltage capacitor bank is connected to the lower end of the vacuum interrupter, and both are connected to the negative terminal of the low-voltage DC source; the negative terminal of the high-voltage diode is connected to the upper end of the vacuum interrupter; and the output terminal of the arc current detection unit is connected to the trigger terminal of the aging switch.

[0017] Preferably, it also includes an operating mechanism for the vacuum interrupter; the operating mechanism of the vacuum interrupter is connected to the vacuum interrupter.

[0018] Preferably, the capacitance value of the low-voltage capacitor bank is greater than the capacitance value of the high-voltage capacitor bank.

[0019] Preferably, the arc-suppressing resistor has a resistance of 10kΩ and the arc-extending resistor has a resistance of 100Ω.

[0020] Compared with existing technologies, the advantages of this invention are as follows: The vacuum interrupter performs a primary closing and opening operation without generating an electric arc under high voltage. Then, using a high-voltage electric field, it captures internal free conductive particles onto the contact surface, followed by a secondary closing and opening operation that generates an electric arc. This creates a follow-current arc between the contacts of the vacuum interrupter. Upon detecting the arc current passing through the vacuum interrupter, a low-voltage, high-current circuit is rapidly applied, expanding the follow-current arc into a aging arc of thousands of amperes. By sequentially applying a high-voltage electric field and aging arc, the free conductive particles inside the vacuum interrupter and the burrs on the contact surface can be effectively eliminated. The high-temperature penetration of the aging arc also releases the gas inside the contacts, which is then absorbed by the getter, thereby reducing the probability of reignition during capacitive switching and lowering the aging cost. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0022] Figure 2 This is a schematic diagram of the follow-through and aging process of the vacuum interrupter in this invention.

[0023] In the diagram: 1 High-voltage DC source, 2 Low-voltage DC source, 3 High-voltage charging switch, 4 High-voltage capacitor bank, 5 Bypass switch, 6 Arc suppression resistor, 7 Arc extension resistor, 8 Vacuum interrupter, 9 Operating mechanism of vacuum interrupter, 10 Arc current detection unit, 11 High-voltage diode, 12 Aging switch, 13 Low-voltage charging switch, 14 Low-voltage capacitor bank. Detailed Implementation

[0024] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, so that those skilled in the art can more clearly understand how to practice the present invention. Although the present invention has been described in conjunction with its preferred embodiments, these embodiments are merely illustrative and not intended to limit the scope of the invention.

[0025] Specific Implementation Example 1: Please refer to... Figure 1 A vacuum interrupter aging device includes a high-voltage DC source 1, a low-voltage DC source 2, a high-voltage charging switch 3, a high-voltage capacitor bank 4, a bypass switch 5, an arc-suppressing resistor 6, an arc-extending resistor 7, a vacuum interrupter 8, an operating mechanism for the vacuum interrupter 9, an arc current detection unit 10, a high-voltage diode 11, an aging switch 12, a low-voltage charging switch 13, and a low-voltage capacitor bank 14.

[0026] One end of the bypass switch 5 is connected to one end of the arc-suppressing resistor 6 and the positive terminal of the high-voltage capacitor bank 4. The other end of the bypass switch 5 is connected to the other end of the arc-suppressing resistor 6 and then connected to the upper end of the vacuum interrupter 8 via the arc-extending resistor 7.

[0027] The high-voltage capacitor bank 4 and the bypass switch 5 are both connected to the positive terminal of the high-voltage DC source 1 through the high-voltage charging switch 3, and the negative terminal of the high-voltage capacitor bank 4 is connected to the negative terminal of the high-voltage DC source 1. The high-voltage capacitor bank 4 provides high voltage to the vacuum interrupter 8 through the arc-suppressing resistor 6 and the arc-extending resistor 7 connected in series, forming a high-voltage electric field between the two contacts of the vacuum interrupter 8 to capture free conductive particles and adsorb them onto the contact surface.

[0028] The positive terminal of the low-voltage capacitor bank 14 is connected to the positive terminal of the high-voltage diode 11 through the aging switch 12, and the positive terminal of the low-voltage capacitor bank 14 is connected to the positive terminal of the low-voltage DC source 2 through the low-voltage charging switch 13; the negative terminal of the low-voltage capacitor bank 14 is connected to the negative terminal of the low-voltage DC source 2.

[0029] The low-voltage capacitor bank 14 provides a large current to the arc between the two contacts of the vacuum interrupter 8 via the aging switch 12 and the high-voltage diode 11. The high temperature of the high-current arc vaporizes the captured and adsorbed free conductive particles, which then condense onto the surface of the shielding cover and other parts and adhere firmly. The high temperature of the high-current arc melts or even vaporizes the burrs on the contact surface, thereby eliminating the burrs. The high temperature also penetrates into the lower layer of the contact surface, thereby releasing the gas inside the contact and having it absorbed by the getter in the vacuum interrupter 8.

[0030] The operating mechanism 9 of the vacuum interrupter is connected to the vacuum interrupter 8; the vacuum interrupter 8 is also equipped with an arc current detection unit 10. Specifically, the lower end of the vacuum interrupter 8 passes through the arc current detection unit 10 and is connected to the negative terminals of the high voltage DC source 1, the low voltage DC source 2, the high voltage capacitor bank 4, and the low voltage capacitor bank 14. The output terminal of the arc current detection unit 10 is connected to the trigger terminal of the aging switch 12 to control the opening or closing of the aging switch 12.

[0031] In this embodiment, the capacitance of the high-voltage capacitor bank 4 is 100μF to 1000μF, and the capacitance of the low-voltage capacitor bank 14 is 0.1F to 1F; the resistance of the arc-suppressing resistor 6 is 10kΩ, and the resistance of the arc-extending resistor 7 is 100Ω.

[0032] Based on the above-mentioned vacuum interrupter aging device, the present invention also proposes an aging method, which specifically includes the following steps:

[0033] Step 1: First, the vacuum interrupter 8 is in the open state, and its contacts are separated; the high voltage charging switch 3 is closed, and the high voltage DC source 1 charges the high voltage capacitor bank 4; the low voltage charging switch 13 is closed, and the low voltage DC source 2 charges the low voltage capacitor bank 14; since the high voltage diode 11 is reverse cut off, the high voltage of the high voltage DC source 1 will not be applied to the low voltage capacitor bank 14 and the low voltage DC source 2.

[0034] After charging is completed, the high-voltage charging switch 3 and the low-voltage charging switch 13 are separated; the bypass switch 5 is separated, and the operating mechanism 9 of the vacuum interrupter drives the vacuum interrupter 8 to perform a closing and opening operation. At the moment the contacts of the vacuum interrupter 8 close, due to the large series resistance of the arc-suppressing resistor 6 and the arc-extending resistor 7, the current passing through the circuit formed by the high-voltage capacitor bank 4, the arc-suppressing resistor 6, the arc-extending resistor 7, and the vacuum interrupter 8 is less than the arc-starting current of the vacuum interrupter 8. When the vacuum interrupter 8 is opened, no arc is generated between the contacts. Therefore, the electrical energy stored in the high-voltage capacitor bank 4 is consumed very little, and its two ends still maintain a high voltage of 10kV to 50kV. This high voltage is applied between the two contacts of the vacuum interrupter 8 to form a high-voltage electric field. The high-voltage electric field captures and adsorbs the free conductive particles inside the vacuum interrupter 8 onto the contact surface.

[0035] Step 2: When the bypass switch 5 is closed, the operating mechanism 9 of the vacuum interrupter drives the vacuum interrupter 8 to perform a secondary closing and opening operation. At the instant the contacts of the vacuum interrupter 8 close, due to the small resistance of the arc-extending resistor 7, the current passing through the circuit formed by the high-voltage capacitor bank 4, the arc-extending resistor 7, and the vacuum interrupter 8 is greater than the arc-starting current of the vacuum interrupter 8. When the vacuum interrupter 8 opens, a follow current arc is generated between the contacts. The initial current value of the follow current arc is 100A to 200A, and the current value of the follow current arc decays exponentially. After the follow current arc is generated between the contacts of the vacuum interrupter 8, the voltage across it is reduced to the arc voltage between the contacts. The remaining high voltage provided by the high-voltage capacitor bank 4 is applied across the arc-extending resistor 7, and the voltage value of the high voltage across the arc-extending resistor 7 decays exponentially.

[0036] Step 3: After the arc current detection unit 10 detects the current flowing through the freewheeling arc in the vacuum interrupter 8, the output terminal of the arc current detection unit 10 outputs a signal to the trigger terminal of the aging switch 12. Upon receiving the signal, the aging switch 12 closes, connecting the circuits at both ends. The voltage across the low-voltage capacitor bank 14 is 100V~200V, which is higher than the sum of the arc voltage across the vacuum interrupter 8 and the conduction voltage of the high-voltage diode 11 (50V~80V). Therefore... When the high-voltage diode 11 is turned on, the low-voltage capacitor bank 14 injects current into the decaying freewheeling arc between the two contacts of the vacuum interrupter 8, causing the freewheeling arc to expand into a calorific arc. The initial current value of the calorific arc is 1kA to 5kA, and the current value of the calorific arc decays exponentially. After a period of 100ms to 1000ms, the current value of the calorific arc decays to the minimum current required to maintain the arc between the two contacts of the vacuum interrupter 8, and the calorific arc extinguishes. The freewheeling and calorific processes of the vacuum interrupter 8 are as follows: Figure 2 As shown.

[0037] This invention discloses a method and apparatus for aging a vacuum interrupter. It utilizes a high-voltage electric field generated between the contacts of the vacuum interrupter by a high-voltage capacitor bank and a large-current arc generated between the contacts of the vacuum interrupter by a low-voltage capacitor bank to age the vacuum interrupter. By sequentially applying the high-voltage electric field and the large-current arc, free conductive particles inside the vacuum interrupter and burrs on the contact surface can be effectively eliminated. The high-temperature penetration of the aging arc also releases the gas inside the contacts, which is then absorbed by the getter, thereby reducing the probability of reignition during capacitive switching and lowering the aging cost.

[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for aging a vacuum interrupter, characterized in that, Includes the following steps: S1: The transient current generated by the discharge of the high-voltage capacitor bank generates a high-voltage electric field of 10kV to 50kV in the vacuum interrupter chamber, while not generating an electric arc; the absence of an electric arc is achieved by setting an arc-suppressing resistor and an arc-extending resistor in series between the high-voltage capacitor bank and the vacuum interrupter chamber to limit the current passing through the vacuum interrupter chamber when it is closed to below the arc-starting current. S2: A 100A to 200A follow current arc is generated in the vacuum interrupter by reducing the resistance between the high-voltage capacitor bank and the vacuum interrupter; the generation of the follow current arc is achieved by retaining the arc-extending resistance by shielding the arc-extinguishing resistor so as to control the current passing through the vacuum interrupter when it is closed to be above the arc-starting current. S3: After detecting the arc current passing through the vacuum interrupter, a 1kA to 5kA calorific arc is generated in the vacuum interrupter through the discharge of the low-voltage capacitor bank until the calorific arcing ends; a calorific switch and a high-voltage diode are set between the low-voltage capacitor bank and the vacuum interrupter, wherein the calorific switch is controlled by the arc current detection unit. After the arc current detection unit detects the arc current passing through the vacuum interrupter, it controls the calorific switch to close, so that the low-voltage capacitor bank is connected to the vacuum interrupter to generate a calorific arc. The low-voltage capacitor bank provides a large current to the arc between the two contacts of the vacuum interrupter via a aging switch and a high-voltage diode. The high temperature of the large-current arc vaporizes the captured and adsorbed free conductive particles and causes them to condense and adhere to the surface of the shield. This melts or vaporizes the burrs on the contact surface and promotes the release of gas inside the contacts, which is then absorbed by the getter.

2. A vacuum interrupter aging device, used to perform the vacuum interrupter aging method as described in claim 1, characterized in that: The system includes a high-voltage triggering component, a low-voltage triggering component, a vacuum interrupter (8), a aging switch (12), an arc current detection unit (10), and a high-voltage diode (11). The high-voltage diode (11) is located between the high-voltage triggering component and the low-voltage triggering component, and the current direction of the high-voltage diode (11) is the same as the current direction in the low-voltage triggering component. The arc current detection unit (10) is located at the lower end of the vacuum interrupter (8), and the output terminal of the arc current detection unit (10) is connected to the aging switch (12) to control the discharge of the low-voltage triggering component. The high-voltage triggering component includes a high-voltage DC source (1), a high-voltage charging switch (3), a high-voltage capacitor bank (4), a bypass switch (5), an arc-suppressing resistor (6), and an arc-extending resistor (7). The positive terminal of the high-voltage capacitor bank (4) and the bypass switch (5) are both connected to the positive terminal of the high-voltage DC source (1) through the high-voltage charging switch (3). The positive terminal of the high-voltage capacitor bank (4) is connected to the arc-suppressing resistor (6) in series. The arc-extending resistor (7) is connected to the upper end of the vacuum interrupter (8); the negative terminal of the high-voltage capacitor bank (4) is connected to the lower end of the vacuum interrupter (8), and both are connected to the negative terminal of the high-voltage DC source (1); the bypass switch (5) is connected in parallel with the arc-extinguishing resistor (6) and in series with the arc-extending resistor (7); the low-voltage triggering component includes a low-voltage DC source (2), a low-voltage charging switch (13), and a low-voltage capacitor bank (14); the positive terminal of the low-voltage capacitor bank (14) is connected to the lower end of the vacuum interrupter (8); the negative terminal of the high-voltage capacitor bank (4) is connected to the upper end of the vacuum interrupter (8), and both are connected to the negative terminal of the high-voltage DC source (1); the bypass switch (5) is connected in parallel with the arc-extinguishing resistor (6) and in series with the arc-extending resistor (7); the low-voltage triggering component includes a low-voltage DC source (2), a low-voltage charging switch (13), and a low-voltage capacitor bank (14); the positive terminal of the low-voltage capacitor bank (14) is connected to the lower ...4); the arc-extending resistor (7) is connected in parallel with the arc-extinguishing resistor (6) and in series with the arc-extending resistor (7); the low-voltage triggering component includes a low-voltage DC source (2), a low-voltage charging switch (13), and The accelerator switch (12) is connected to the positive terminal of the high-voltage diode (11) and to the positive terminal of the low-voltage DC source (2) through the low-voltage charging switch (13); the negative terminal of the low-voltage capacitor bank (14) is connected to the lower end of the vacuum interrupter (8), and both are connected to the negative terminal of the low-voltage DC source (2); the negative terminal of the high-voltage diode (11) is connected to the upper end of the vacuum interrupter (8); the output terminal of the arc current detection unit (10) is connected to the trigger terminal of the accelerator switch (12).

3. The aging device for a vacuum interrupter according to claim 2, characterized in that: It also includes an operating mechanism (9) for the vacuum interrupter; the operating mechanism (9) for the vacuum interrupter is connected to the vacuum interrupter (8).

4. The aging device for a vacuum interrupter according to claim 2, characterized in that: The capacitance of the low-voltage capacitor bank (14) is greater than that of the high-voltage capacitor bank (4).

5. The aging device for a vacuum interrupter according to claim 2, characterized in that: The arc-suppressing resistor (6) has a resistance value of 10kΩ, and the arc-extending resistor (7) has a resistance value of 100Ω.

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