Device and method for testing arc voltage characteristics of vacuum interrupter with external magnetic blowing magnetic field

Abstract

The present invention provides a device and method for testing arc voltage characteristics of a vacuum interrupter with an external magnetic blowing magnetic field, including a test main circuit composed of a resonant current source charging system, a resonant current source, a discharge switch, a current, an arc voltage measuring device, and a vacuum interrupter connected in series in sequence; an electromagnetic repulsion mechanism is connected to the vacuum interrupter and is an actuator of the vacuum interrupter; a magnetic blowing magnetic field generating device constitutes an external magnetic blowing magnetic field generating device; and a control device is a control part of the entire test device. The present invention is used to test the arc voltage and characteristics of a vacuum interrupter with an external magnetic blowing device during high-speed opening. By arbitrarily and accurately adjusting the interval time between the magnetic blowing magnetic field application time and the vacuum interrupter opening time, and adopting an adjustable magnetic blowing magnetic field generating device, it can be used for the design and verification of a high-arc voltage vacuum interrupter with a magnetic blowing magnetic field, and can quickly realize the test verification and parameter optimization of such vacuum interrupters.

Description

Technical Field

[0001] The invention relates to the field of high-voltage switch testing equipment, and in particular to a vacuum interrupter arc voltage characteristic testing device with an external magnetic blowing magnetic field and a method thereof. Background Art

[0002] As an essential key equipment for building a DC distribution network, medium-voltage DC circuit breakers are the basic guarantee for the safe operation of the system. Medium-voltage DC circuit breakers are composed of a main branch, a transfer branch, and an energy-consuming branch in parallel. When the circuit breaker is on, the current flows through the main branch; when the circuit breaker is off, the main branch is quickly mechanically disconnected, and the main branch current is quickly transferred to the transfer branch. Then, the power electronic devices of the transfer branch realize arc-free current interruption, and finally the energy is absorbed through the energy-consuming branch and the transient recovery voltage is limited.

[0003] Since the arc voltage of the vacuum interrupter of the fast mechanical switch is generally around 20V when breaking the current, this arc voltage is lower than or slightly higher than the conduction voltage drop of the power electronic devices in the transfer branch, making it difficult to achieve rapid current transfer. Therefore, the main branch generally needs to be connected in series with fully controlled power electronic devices to assist in achieving rapid current transfer. However, the added power electronic devices are expensive, and they have large losses and serious heat when passing normal load current. Water cooling devices are also required to force heat dissipation, which further increases the cost of medium-voltage DC circuit breakers, making them low in cost performance and difficult to promote.

[0004] By applying an external magnetic field to the vacuum interrupter to control the arc generated when the current is interrupted, the arc voltage is increased, and the current is quickly transferred to the transfer branch. This method is low-cost and highly reliable. It is an effective solution to solve the problem of rapid current transfer from the main branch to the transfer branch and has high application value.

[0005] The effect of external magnetic field on the arc voltage of vacuum interrupter is affected by factors such as magnetic field size, magnetic field application time, magnetic field distribution, interrupter structure, switch opening speed, etc., and factors such as cost, installation space and impact on arc extinguishing performance also need to be considered. Therefore, a large number of tests are required to determine the best design scheme when designing such interrupter. However, there is currently a lack of special test equipment for such tests, so there is a lack of fast and effective means to verify the performance of vacuum interrupter with external magnetic blow-off magnetic field.

[0006] At present, the existing vacuum arc chamber arc test devices cannot be directly used for such tests. First, these devices are mainly used to study the arc extinguishing performance of ordinary circuit breakers. They cannot generate a controllable external magnetic field and cannot be used to verify the influence of the above factors on the arc. In addition, the switch operating mechanism of the existing device is a traditional operating mechanism, which cannot simulate the high-speed movement characteristics of a fast mechanical switch, and it is difficult to realize the arc characteristic test under the actual working conditions of the circuit breaker. Finally, the existing switch arc test device lacks a precise control system, and it is difficult to achieve precise timing coordination of the current moment, the external magnetic field application moment and the switch opening moment.

[0007] By applying a magnetic field outside the vacuum interrupter, the arc voltage of the vacuum interrupter can be effectively increased. Since the effect of the external magnetic field on the arc voltage of the vacuum interrupter is affected by factors such as the size of the magnetic field, the time of applying the magnetic field, the distribution of the magnetic field, the structure of the interrupter, and the speed of the switch opening, a large number of experiments are required to study their effects on the arc. At present, the existing vacuum interrupter arc test devices cannot be directly used for such tests. First, these devices are mainly used to study the arc extinguishing performance of ordinary circuit breakers. They cannot generate a controllable external magnetic field and cannot be used to verify the effects of the above factors on the arc. In addition, the switch operating mechanism of the existing device is a traditional operating mechanism, which cannot simulate the high-speed motion characteristics of a fast mechanical switch, and it is difficult to realize the arc characteristic test under the actual working conditions of the circuit breaker. Finally, the existing switch arc test device lacks a precise control system, and it is difficult to achieve precise timing coordination of the current moment, the external magnetic field application moment, and the switch opening moment. Summary of the invention

[0008] The effect of the external magnetic field on the arc voltage of the vacuum interrupter is affected by factors such as the size of the magnetic field, the time of magnetic field application, the distribution of the magnetic field, the structure of the interrupter, the speed of the switch opening, and other factors. At the same time, factors such as cost, installation space, and the impact on arc extinguishing performance must also be considered. Therefore, a large number of tests are required to determine the best design solution when designing such an interrupter. However, there is currently a lack of special test equipment for such tests, which means that there is a lack of fast and effective means to verify the performance of such vacuum interrupters.

[0009] In view of the above technical problems, the purpose of the present invention is to provide a device and method for testing the arc voltage and characteristics of a vacuum interrupter with an external magnetic blowing device during high-speed opening.

[0010] The specific technical solutions are:

[0011] The arc voltage characteristic test device of the vacuum interrupter with an external magnetic blowing magnetic field comprises a test main circuit composed of a resonant current source charging system, a resonant current source, a discharge switch, a current and arc voltage measuring device, and a vacuum interrupter connected in series in sequence; the electromagnetic repulsion mechanism is connected to the vacuum interrupter and is the actuator of the vacuum interrupter; the magnetic blowing magnetic field generating device constitutes an external magnetic blowing magnetic field generating device; the control device is the control part of the entire test device;

[0012] Resonant current source charging system: consists of a charging power supply and a charging switch, and is used to charge the capacitor of the resonant current source.

[0013] Resonant current source: including inductance and capacitance, used to generate low-frequency and high current required for the test

[0014] Discharge switch: It receives the control signal from the control device and closes to make the resonant current source discharge to generate the low-frequency high current required for the test;

[0015] Control device: Control the discharge switch to close according to a certain timing to generate low-frequency current, control the electromagnetic repulsion mechanism to drive the vacuum interrupter to break, and control the magnetic blow magnetic field generating device to close to generate a magnetic blow magnetic field;

[0016] Display and recording device: receives input signals from current and arc voltage measuring devices, and is used to display and record the current and arc voltage in the test;

[0017] Current and arc voltage measuring device: used to convert low-frequency high current and arc voltage into measurable signals;

[0018] Vacuum interrupter: The current is interrupted by the electromagnetic repulsion mechanism, and an arc will be generated between the internal contacts until the current is 0;

[0019] Electromagnetic repulsion mechanism: receives control signals from the control device to drive the vacuum interrupter to break quickly;

[0020] Magnetic blow magnetic field generating device: includes capacitor, thyristor, magnetic blow coil and diode. After receiving the control signal of the control device, it triggers the thyristor to conduct, so that the capacitor discharges to the magnetic blow coil through the thyristor to generate a magnetic blow magnetic field. The capacitor voltage, the relative position of the coil and the vacuum interrupter, and the discharge time can be adjusted as needed.

[0021] The magnetic blowing coil adopts a double-layer disc winding method, including two coils, which are connected in series; the two coils are symmetrically distributed at both ends of the vacuum interrupter, and the distance between the coil and the vacuum interrupter is L. The distance L can be adjusted as needed to change the effect of the magnetic blowing coil on the arc voltage.

[0022] The method for testing arc voltage characteristics of a vacuum interrupter with an external magnetic blowing magnetic field comprises the following steps:

[0023] Step 1: The charging switch of the resonant current source charging system is closed, and the charging power supply charges the capacitor of the resonant current source. After charging to a preset voltage, the charging switch is disconnected;

[0024] Step 2: The control device first sends a closing control signal to the discharge switch, the discharge switch is closed, and the LC resonant circuit generates a low-frequency test current;

[0025] Step 3: After time t1, the control device sends a disconnection control signal to the electromagnetic repulsion mechanism, and the electromagnetic repulsion mechanism drives the moving and static contacts of the vacuum interrupter to separate and disconnect the low-frequency test current;

[0026] Step 4: After time t2, the control device sends a control signal to the magnetic blowing magnetic field generating device, and the coil in the magnetic blowing magnetic field generating device is energized to generate a magnetic blowing magnetic field;

[0027] Step 5: During the test, the current and arc voltage measuring device tests the arc voltage and current in the vacuum interrupter, and the display and recording device records and displays the test data.

[0028] Beneficial effects brought by the technical solution of the present invention:

[0029] This test device can be used to test the arc voltage and characteristics of vacuum interrupters with external magnetic blowing devices during high-speed opening. Through the arbitrary and precise adjustment of the interval between the magnetic blowing magnetic field application time and the vacuum interrupter opening time, and the use of an adjustable magnetic blowing magnetic field generating device, it can be used for the design and verification of high-arc voltage vacuum interrupters with magnetic blowing magnetic fields, and can quickly realize the test verification and parameter optimization of such vacuum interrupters. At the same time, the test device uses an electromagnetic repulsion mechanism to drive the vacuum interrupter, realizing the arc voltage and characteristic test under high-speed opening, which is close to the actual working conditions of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the principle of the testing device of the present invention;

[0031] Figure 2 It is a schematic diagram of the winding and connection of the magnetic blow coil of the present invention;

[0032] Figure 3 This is a schematic diagram of the arrangement of the magnetic blow coil in the test device of the present invention:

[0033] Figure 4 This is the magnetic field distribution diagram of the magnetic blowing coil of the present invention:

[0034] Figure 5 It is a test flow chart of the present invention;

[0035] Figure 6 This is a test control timing diagram of the embodiment. DETAILED DESCRIPTION

[0036] The specific technical solution of the present invention is described in conjunction with the accompanying drawings.

[0037] Figure 1 This is a schematic diagram of the principles of the device and method for testing arc voltage characteristics of a vacuum arc chamber with an external magnetic blowing magnetic field involved in the present invention. The present invention adopts an external adjustable magnetic blowing magnetic field generating device and a fast switch with an electromagnetic repulsion mechanism. The testing device includes a test main circuit composed of a resonant current source charging system 1, a resonant current source 2, a discharge switch 3, a current and arc voltage measuring device 6, and a vacuum arc chamber 7 connected in series in sequence; the electromagnetic repulsion mechanism 8 is connected to the vacuum arc chamber 7 and is the actuator of the vacuum arc chamber 7; the magnetic blowing magnetic field generating device 9 constitutes an external magnetic blowing magnetic field generating device; and the control device 4 is the control part of the entire test device.

[0038] Resonant current source charging system 1: consists of a charging power supply and a charging switch, and is used to charge the capacitor C of the resonant current source 2.

[0039] Resonant current source 2: includes inductor L and capacitor C, used to generate low-frequency high current required for the test

[0040] Discharge switch 3: receives the control signal of the control device 4 and closes, so that the resonant current source 2 discharges to generate the low-frequency high current required for the test;

[0041] Control device 4: controls the discharge switch 3 to close according to a certain timing to generate a low-frequency current, controls the electromagnetic repulsion mechanism 8 to drive the vacuum interrupter 7 to break, and controls the magnetic blow magnetic field generating device 9 to close to generate a magnetic blow magnetic field;

[0042] Display and recording device 5: receives input signals from current and arc voltage measuring device 6, and is used to display and record the current and arc voltage in the test;

[0043] Current and arc voltage measuring device 6: used to convert low-frequency high current and arc voltage into measurable signals;

[0044] Vacuum interrupter 7: The current is interrupted under the drive of the electromagnetic repulsion mechanism 8, and an arc will be generated between the internal contacts until the current is 0;

[0045] Electromagnetic repulsion mechanism 8: receives control signal from control device 4 to drive vacuum interrupter 7 to break quickly;

[0046] The magnetic blowing magnetic field generating device 9 includes a capacitor, a thyristor, a magnetic blowing coil and a diode. After receiving the control signal of the control device 4, the thyristor is triggered to conduct, so that the capacitor discharges to the magnetic blowing coil through the thyristor to generate a magnetic blowing magnetic field. The capacitor voltage, the relative position of the coil and the vacuum interrupter 7, and the discharge time can be adjusted as needed.

[0047] like Figure 2As shown, the magnetic blowing coil adopts a double-layer disc winding method, with two coils in total, and the two coils are connected in series.

[0048] like Figure 3 As shown, the two coils are symmetrically distributed at both ends of the vacuum interrupter 7, and the distance between them and the vacuum interrupter 7 is L. The distance L can be adjusted as needed to change the effect of the magnetic blow coil on the arc voltage.

[0049] like Figure 4 As shown, the magnetic field generated by the magnetic blow coil should pass through the vacuum interrupter 7 perpendicular to the current direction of the vacuum interrupter 7, and its direction should point from one coil to another coil.

[0050] Figure 5 This is the operation flow chart of the test device. The test process of this test device is:

[0051] Step 1: The charging switch of the resonant current source charging system 1 is closed, and the charging power source charges the capacitor C of the resonant current source 2. After charging to a preset voltage, the charging switch is turned off;

[0052] Step 2: The control device 4 first sends a closing control signal to the discharge switch 3, the discharge switch 3 is closed, and the LC resonant circuit generates a low-frequency test current;

[0053] Step 3: After time t1, the control device 4 sends a disconnection control signal to the electromagnetic repulsion mechanism 8, and the electromagnetic repulsion mechanism 8 drives the moving and static contacts of the vacuum interrupter 7 to separate and disconnect the low-frequency test current;

[0054] Step 4: After time t2, the control device 4 sends a control signal to the magnetic blowing magnetic field generating device 9, and the coil inside the magnetic blowing magnetic field generating device 9 is energized to generate a magnetic blowing magnetic field;

[0055] Step 5: During the test, the current and arc voltage measuring device 6 tests the arc voltage and current in the vacuum interrupter 7, and the display and recording device 5 records and displays the test data.

[0056] Figure 6 The test control timing diagram is given.

Claims

1. A vacuum interrupter arc voltage characteristic test device with an external magnetic blowing magnetic field, characterized in that: The test device comprises a main circuit composed of a resonant current source charging system (1), a resonant current source (2), a discharge switch (3), a current and arc voltage measuring device (6), and a vacuum arc extinguishing chamber (7) connected in series in sequence; an electromagnetic repulsion mechanism (8) is connected to the vacuum arc extinguishing chamber (7) and is an actuator of the vacuum arc extinguishing chamber (7); a magnetic blow-out magnetic field generating device (9) constitutes an external magnetic blow-out magnetic field generating device; and a control device (4) is a control part of the entire test device; A resonant current source charging system (1): composed of a charging power supply and a charging switch, and used for charging the capacitor (C) of the resonant current source (2); Resonant current source (2): includes inductance (L) and capacitance (C), used to generate low-frequency high current required for the test; Discharge switch (3): receives the control signal of the control device (4) and closes, so that the resonant current source (2) discharges to generate the low-frequency high current required for the test; A control device (4) controls the discharge switch (3) to close according to a certain time sequence to generate a low-frequency current, controls the electromagnetic repulsion mechanism (8) to drive the vacuum interrupter (7) to disconnect, and controls the magnetic blow-out magnetic field generating device (9) to close to generate a magnetic blow-out magnetic field; Display and recording device (5): receiving input signals from the current and arc voltage measuring device (6), and used for displaying and recording the current and arc voltage in the test; Current and arc voltage measuring device (6): used to convert low-frequency high current and arc voltage into measurable signals; Vacuum interrupter (7): The current is interrupted under the drive of the electromagnetic repulsion mechanism (8), and an arc is generated between the internal contacts until the current reaches zero; Electromagnetic repulsion mechanism (8): receiving a control signal from the control device (4) to drive the vacuum interrupter (7) to quickly disconnect; A magnetic blowing magnetic field generating device (9): comprising a capacitor, a thyristor, a magnetic blowing coil and a diode, which triggers the thyristor to conduct after receiving a control signal from the control device (4), so that the capacitor discharges to the magnetic blowing coil through the thyristor to generate a magnetic blowing magnetic field. The capacitor voltage, the relative position of the coil and the vacuum interrupter (7), and the discharge time can be adjusted as required; The testing method of the testing device comprises the following steps: Step 1: The charging switch of the resonant current source charging system (1) is closed, and the charging power source charges the capacitor (C) of the resonant current source (2); after charging to a preset voltage, the charging switch is disconnected; Step 2: The control device (4) first sends a closing control signal to the discharge switch (3), the discharge switch (3) is closed, and the LC resonant circuit generates a low-frequency test current; Step 3: After time t1 has passed, the control device (4) sends a disconnection control signal to the electromagnetic repulsion mechanism (8), and the electromagnetic repulsion mechanism (8) drives the moving and static contacts of the vacuum interrupter (7) to separate, thereby disconnecting the low-frequency test current; Step 4: After time t2 has passed, the control device (4) sends a control signal to the magnetic blowing magnetic field generating device (9), and the coil inside the magnetic blowing magnetic field generating device (9) is energized to generate a magnetic blowing magnetic field; Step 5: During the test, the current and arc voltage measuring device (6) tests the arc voltage and current in the vacuum interrupter (7), and the display recording device (5) records and displays the test data.

2. The arc voltage characteristic testing device of a vacuum interrupter with an external magnetic blowing magnetic field according to claim 1, characterized in that: The magnetic blow coil adopts a double-layer disc winding method and comprises two coils, which are connected in series; the two coils are symmetrically distributed at both ends of the vacuum interrupter (7), and the distance between the coil and the vacuum interrupter (7) is L. The distance L can be adjusted as required to change the effect of the magnetic blow coil on the arc voltage.

Images