Current breaking device, current breaking module and control method

Abstract

This application proposes a current-breaking device, a current-breaking module, and a control method. The current-breaking device includes a current-carrying branch, a transfer branch, an oscillation branch, and an energy-dissipating branch. The current-carrying branch is connected in parallel with the transfer branch and the oscillation branch. The current-carrying branch is composed of a mechanical switch and a current-carrying unit connected in series. The transfer branch is composed of a bidirectional conducting thyristor unit and an active power electronic unit connected in series. The oscillation branch is composed of an oscillating capacitor, a damping and vibration-suppressing unit, and an oscillating inductor connected in series. The energy-dissipating branch is connected in parallel with the oscillating capacitor, or in parallel with the oscillating capacitor and the damping and vibration-suppressing unit connected in series, or in parallel with the oscillating capacitor and the oscillating inductor connected in series, or in parallel with the current-carrying branch. According to the embodiments of this application, it has advantages such as reliable mechanical switch breaking, short breaking time for small currents, high redundancy, and good equipment economy.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and more specifically, to a current-breaking device, a current-breaking module, and a control method. Background Technology

[0002] In DC applications, due to the rapid increase in fault current in DC transmission and distribution systems, reliable and rapid fault isolation and recovery are crucial for ensuring their safe and stable operation. Existing DC circuit breakers include mechanical DC circuit breakers, hybrid DC circuit breakers, and all-solid-state DC circuit breakers. Mechanical DC circuit breakers can be further divided into passive oscillation technology and active oscillation technology. Because mechanical DC circuit breakers use capacitors, they are bulky, require a long time to interrupt small currents, have a high risk of zero-crossing reignition, and are prone to oscillation with the DC system during the interruption process, posing a threat to the normal and safe operation of the system and other equipment. Hybrid DC circuit breakers combine mechanical switching and power electronics technology, achieving controllable current interruption through power electronic devices. They feature arc-free operation and fast reclosing, offering good system applicability. However, their interruption current performance and economic efficiency are limited by the fully controlled power electronic devices, hindering their large-scale application in high-voltage DC transmission systems. Because of their high current loss, all-solid-state DC circuit breakers are generally not chosen for fault isolation and recovery.

[0003] The inventors have discovered that in AC applications, conventional AC circuit breakers can only interrupt the current by naturally extinguishing it at the current zero-crossing point. However, the large peak value of the first half-wave fault current can have an adverse effect on some sensitive or important equipment. Therefore, there is an urgent need for AC circuit breakers that can interrupt the current quickly in advance. Summary of the Invention

[0004] This application provides a device, module, and control method for interrupting current, which are used to solve the problems of high risk of mechanical switch reignition, long interruption time for small currents, significant system oscillation, and high equipment cost in the prior art of DC circuit breakers, as well as the impact of high amplitude fault current in the first half wave on sensitive or important equipment when AC circuit breakers are interrupted.

[0005] According to one aspect of this application, a current-breaking device is proposed, the current-breaking device comprising a current-carrying branch, a transfer branch, an oscillation branch, and an energy-dissipating branch, wherein the current-carrying branch, the transfer branch, and the oscillation branch are connected in parallel; the current-carrying branch is composed of a mechanical switch and a current-carrying unit connected in series; the transfer branch is composed of a bidirectional conducting thyristor unit and an active power electronic unit connected in series.

[0006] The oscillation branch is composed of an oscillation capacitor, a damping vibration suppression unit, and an oscillation inductor connected in series; the energy dissipation branch is connected in parallel with the oscillation capacitor, or in parallel with the oscillation capacitor and the damping vibration suppression unit connected in series, or in parallel with the oscillation capacitor and the oscillation inductor connected in series, or in parallel with the current-carrying branch.

[0007] According to some embodiments, the active power electronic unit is composed of at least one active power electronic module with bypass function connected in series. The active power electronic module with bypass function includes a power electronic switch, an active power electronic module bypass switch, and a voltage source. The power electronic switch includes a first power electronic switch and a second power electronic switch. The active power electronic module bypass switch includes a first bypass switch. The voltage source includes a first voltage source. The positive terminal of the first power electronic switch is connected to the positive terminal of the first voltage source. The negative terminal of the first power electronic switch is connected to the positive terminal of the second power electronic switch and then led out with an external wire. The negative terminal of the second power electronic switch is connected to the negative terminal of the first voltage source and then led out with an external wire. The first bypass switch is connected in parallel between the two external wires.

[0008] The active power electronic module with bypass function includes a power electronic switch, an active power electronic module bypass switch, and a voltage source. The power electronic switch includes a third, fourth, fifth, and sixth power electronic switch. The active power electronic module bypass switch is a second bypass switch. The voltage source includes a second voltage source. The positive terminal of the third power electronic switch is connected to the positive terminals of the fifth power electronic switch and the second voltage source, respectively. The negative terminal of the third power electronic switch is connected to the positive terminal of the fourth power electronic switch and then led out with an external wire. The negative terminal of the fourth power electronic switch is connected to the negative terminals of the sixth power electronic switch and the second voltage source, respectively. The negative terminal of the fifth power electronic switch is connected to the positive terminal of the sixth power electronic switch and then led out with an external wire. The second bypass switch is connected in parallel between the two external wires.

[0009] The active power electronic module with bypass function includes a power electronic switch, an active power electronic module bypass switch, and a voltage source. The power electronic switch includes a seventh power electronic switch and an eighth power electronic switch. The active power electronic module bypass switch includes a third bypass switch. The voltage source includes a third voltage source and a fourth voltage source. The positive terminal of the seventh power electronic switch is connected to the positive terminal of the third voltage source. The negative terminal of the seventh power electronic switch is connected to the positive terminal of the eighth power electronic switch and then led out with an external wire. The negative terminal of the eighth power electronic switch is connected to the negative terminal of the fourth voltage source. The negative terminal of the third voltage source is connected to the positive terminal of the fourth voltage source and then led out with an external wire. The third bypass switch is connected in parallel between the two external wires.

[0010] According to some embodiments, the operating modes of the active power electronic module with bypass function include an exit mode and an input mode. In the exit mode, the bypass switch of the active power electronic module is closed; in the input mode, the bypass switch of the active power electronic module is open.

[0011] According to some embodiments, the active power electronic unit is composed of at least one active power electronic module with isolation function connected in parallel. The active power electronic module with isolation function includes a power electronic switch, an isolating switch, and a voltage source. The power electronic switch includes a ninth power electronic switch and a tenth power electronic switch. The isolating switch includes a first isolating switch. The voltage source includes a fifth voltage source. The positive terminal of the ninth power electronic switch is connected to the positive terminal of the fifth voltage source. The negative terminal of the ninth power electronic switch is connected to the positive terminal of the tenth power electronic switch and the first terminal of the first isolating switch. The second terminal of the first isolating switch has an external wire leading out. The negative terminal of the tenth power electronic switch is connected to the negative terminal of the fifth voltage source and then has an external wire leading out. Or

[0012] The active power electronic module with isolation function includes a power electronic switch, an isolating switch, and a voltage source. The power electronic switch includes an eleventh, twelfth, thirteenth, and fourteenth power electronic switches. The isolating switch includes a second isolating switch. The voltage source includes a sixth voltage source. The positive terminal of the eleventh power electronic switch is connected to the positive terminals of the thirteenth and sixth voltage sources. The negative terminal of the eleventh power electronic switch is connected to the positive terminal of the twelfth power electronic switch and then led out with an external wire. The negative terminal of the twelfth power electronic switch is connected to the negative terminals of the fourteenth and sixth voltage sources. The negative terminal of the thirteenth power electronic switch is connected to the positive terminal of the fourteenth power electronic switch and the first terminal of the second isolating switch. The second terminal of the second isolating switch leads out with an external wire.

[0013] The active power electronic module with isolation function includes a power electronic switch, an isolating switch, and a voltage source. The power electronic switch includes a fifteenth power electronic switch and a sixteenth power electronic switch. The isolating switch includes a third isolating switch. The voltage source includes a seventh voltage source and an eighth voltage source. The positive terminal of the fifteenth power electronic switch is connected to the positive terminal of the seventh voltage source. The negative terminal of the fifteenth power electronic switch is connected to the positive terminal of the sixteenth power electronic switch and then led out with an external wire. The negative terminal of the sixteenth power electronic switch is connected to the negative terminal of the eighth voltage source. The negative terminal of the seventh voltage source is connected to the positive terminal of the eighth voltage source and the first terminal of the third isolating switch. The second terminal of the third isolating switch leads out with an external wire.

[0014] According to some embodiments, the operating modes of the active power electronic module with isolation function include an off mode and an on mode. In the off mode, the isolation switch is open; in the on mode, the isolation switch is closed.

[0015] According to some embodiments, the bidirectional thyristor unit includes a bidirectional thyristor; or

[0016] The bidirectional thyristor unit includes a first unidirectional thyristor and a second unidirectional thyristor, which are connected in parallel in opposite directions.

[0017] According to some embodiments, the damping and vibration suppression unit includes a fifth diode, a sixth diode, and a first vibration suppression capacitor. The positive terminal of the fifth diode is connected to the first terminal of the first vibration suppression capacitor and then led out with an external wire. The negative terminal of the fifth diode is connected to the positive terminal of the sixth diode and then led out with an external wire. The negative terminal of the sixth diode is connected to the second terminal of the first vibration suppression diode; or

[0018] The damping and vibration suppression unit includes a seventh diode, an eighth diode, a ninth diode, a tenth diode, and a second vibration suppression capacitor. The seventh diode, the eighth diode, the ninth diode, and the tenth diode form a diode full bridge. The positive and negative terminals of the DC side of the diode full bridge are connected to the first and second terminals of the second vibration suppression capacitor, respectively. The AC side of the diode full bridge forms two lead-out connection lines.

[0019] According to some embodiments, the current-carrying unit is composed of at least one bidirectional current-carrying module connected in series and parallel with a current-carrying unit bypass switch; and / or the mechanical switch is composed of one or more mechanical switches connected in series and parallel; and / or the oscillating capacitor is composed of one or more capacitors connected in series and parallel; and / or the oscillating inductor is composed of one or more inductors connected in series and parallel; and / or the energy-dissipating branch is composed of one or more surge arresters connected in series and parallel.

[0020] According to some embodiments, the power electronic switch is composed of at least one stage of power semiconductor devices connected in series. The power semiconductor devices include fully controlled power semiconductor devices or semi-controlled power semiconductor devices. The fully controlled power semiconductor devices are one or any combination of IGBT, IEGT, IGCT, MOSFET, and GTO. The semi-controlled power semiconductor devices are thyristors. And / or the voltage source is a pre-charged capacitor, or an energy storage battery, or an AC rectified power supply.

[0021] According to one aspect of this application, a current-breaking module is proposed, the current-breaking module comprising at least two current-breaking devices as described in any of the preceding embodiments, and the current-breaking devices being connected in series.

[0022] According to one aspect of this application, a control method for a current-breaking device is proposed. The control method is used to control the current-breaking device as described in any of the preceding embodiments. The control method includes, in response to a system normal operation command, current flows through a current-carrying branch, the mechanical switch of the current-carrying branch is in a closed state, the current-carrying unit is in a current-carrying unit bypass switch closed state, and the active power electronic unit in the transfer branch's input mode is in a disconnected or locked state; in response to a tripping command received when a system fault occurs, the mechanical switch of the current-carrying branch is opened, and the current-carrying unit bypass switch of the current-carrying unit is opened and the bidirectional current-carrying module is turned on; when the current-carrying unit bypass switch of the current-carrying unit is separated to the insulation position, and the current in the current-carrying unit bypass switch is completely transferred to the bidirectional current-carrying module. When the module is in operation, the bidirectional thyristor unit of the trigger transfer branch is turned on and the bidirectional current-carrying module of the control current-carrying unit is turned off. When the mechanical switch is separated to the insulation position, the active power electronic unit of the control transfer branch outputs a multi-pulse square wave voltage. The output square wave voltage excites the oscillating capacitor and oscillating inductor of the oscillating branch to oscillate, generating an oscillating current with the same amplitude and opposite direction as the fault current. The oscillating current causes the bidirectional thyristor unit of the transfer branch to break at a zero-crossing point. When the current of the transfer branch crosses zero, the fault current begins to charge the oscillating capacitor of the oscillating branch. When the voltage of the oscillating capacitor is greater than the residual voltage of the energy-consuming branch, the fault current is transferred to the energy-consuming branch and dissipated to zero, the circuit breaker is successfully tripped and the tripping operation ends.

[0023] According to one aspect of this application, a control method for a current-breaking device is proposed. The control method is used to control the current-breaking device as described in any of the preceding embodiments. The control method includes, in response to a system normal operation command, current flows through a current-carrying branch, where the mechanical switch of the current-carrying branch is closed, the current-carrying unit is in a current-carrying unit bypass switch open and the bidirectional current-carrying module is in a conducting state, and the active power electronic unit in the transfer branch's input mode is in a disconnected or locked state; in response to a tripping command received when a system fault occurs, triggering the bidirectional conducting thyristor unit of the transfer branch to conduct, and controlling the bidirectional current-carrying module of the current-carrying unit to disconnect; when the current is completely transferred from the current-carrying branch to the transfer branch... After the transfer branch is moved, the mechanical switch is opened without arcing. When the mechanical switch is opened to the insulation position, the active power electronic unit of the transfer branch outputs a multi-pulse square wave voltage. The output square wave voltage excites the oscillating capacitor and oscillating inductor of the oscillating branch to oscillate, generating an oscillating current with the same amplitude and opposite direction as the fault current. The oscillating current causes the bidirectional conducting thyristor unit of the transfer branch to break at a zero-crossing point. When the current of the transfer branch crosses zero, the fault current begins to charge the oscillating capacitor of the oscillating branch. When the voltage of the oscillating capacitor is greater than the residual voltage of the energy-consuming branch, the fault current begins to transfer to the energy-consuming branch and dissipates to zero, the circuit breaker is successfully tripped and the tripping operation ends.

[0024] According to the embodiments of this application, when the device for breaking the current trips, by controlling the operating state of the internal components of the current-carrying branch, the transfer branch, and the oscillation branch, the current in the current-carrying branch is first transferred to the transfer branch. Then, the square wave voltage output by the active power electronic unit generates an oscillating current with the same amplitude and opposite direction as the fault current, so that the transfer branch crosses zero and breaks naturally. This overcomes the problems of high risk of mechanical switch reignition, long breaking time for small currents, significant system oscillation, and high equipment cost, which is conducive to the large-scale promotion and application of AC / DC power transmission and distribution systems.

[0025] According to other embodiments, the active power electronic unit of the current-carrying branch adopts the active oscillation boost principle to increase the reverse injection current amplitude. The active power electronic unit has fewer modules and is configured with redundancy, which significantly improves the economy and reliability of the equipment.

[0026] According to other embodiments, the oscillation capacitor of the oscillation branch is a pulse capacitor with high voltage withstand capability and a capacitance value in the microF range, which reduces the breaking time of small currents and also reduces the capacitor size and cost. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0028] Figure 1 A block diagram of a current-breaking device according to an example embodiment of this application is shown.

[0029] Figure 2 A schematic diagram of a current-breaking device circuit structure is shown according to an example embodiment of this application.

[0030] Figure 3 A schematic diagram of a current-breaking device circuit structure is shown according to an example embodiment of this application.

[0031] Figure 4 A schematic diagram of a current-breaking device circuit structure is shown according to an example embodiment of this application.

[0032] Figure 5 A schematic diagram of a current-breaking device circuit structure is shown according to an example embodiment of this application.

[0033] Figure 6 A schematic diagram of a current-breaking device circuit structure is shown according to an example embodiment of this application.

[0034] Figure 7 A schematic diagram of a current-breaking device circuit structure is shown according to an example embodiment of this application.

[0035] Figure 8 A schematic diagram of a current-breaking device circuit structure is shown according to an example embodiment of this application.

[0036] Figure 9 A schematic diagram of a current-breaking device circuit structure is shown according to an example embodiment of this application.

[0037] Figure 10a This diagram illustrates the circuit structure of an active power electronic module with bypass function according to an example embodiment of this application.

[0038] Figure 10b This diagram illustrates the circuit structure of another active power electronic module with bypass function according to an example embodiment of this application.

[0039] Figure 10c This diagram illustrates the circuit structure of another active power electronic module with bypass function according to an example embodiment of this application.

[0040] Figure 11a This diagram illustrates a circuit structure of an active power electronic module with isolation functionality according to an example embodiment of this application.

[0041] Figure 11bThis diagram illustrates a circuit structure of an active power electronic module with isolation functionality according to an example embodiment of this application.

[0042] Figure 11c This diagram illustrates a circuit structure of an active power electronic module with isolation functionality according to an example embodiment of this application.

[0043] Figure 12a A schematic diagram of the circuit structure of a bidirectional thyristor unit for a transfer branch according to an example embodiment of this application is shown.

[0044] Figure 12b A schematic diagram of the circuit structure of a bidirectional thyristor unit for a transfer branch according to an example embodiment of this application is shown.

[0045] Figure 13a A schematic diagram of the circuit topology of a current-carrying unit according to an example embodiment of this application is shown.

[0046] Figure 13b A schematic diagram of another circuit topology of the current-carrying unit according to an example embodiment of this application is shown.

[0047] Figure 13c A schematic diagram of another circuit topology of the current-carrying unit according to an example embodiment of this application is shown.

[0048] Figure 13d A schematic diagram of another circuit topology of the current-carrying unit according to an example embodiment of this application is shown.

[0049] Figure 14a A circuit structure diagram of a damping vibration suppression unit for an oscillation branch according to an example embodiment of this application is shown.

[0050] Figure 14b A circuit structure diagram of a damping vibration suppression unit for an oscillation branch according to an example embodiment of this application is shown.

[0051] Figure 15 A block diagram illustrating a current-breaking module structure according to an example embodiment of this application is shown.

[0052] Figure 16 This diagram illustrates a different current-breaking module structure according to an example embodiment of the present application.

[0053] Figure 17 A flowchart of a control method according to an example embodiment of this application is shown.

[0054] Figure 18a A schematic diagram showing the current flow direction under the control method according to an example embodiment of this application is shown.

[0055] Figure 18bThis diagram illustrates another current flow direction under the control method according to an example embodiment of this application.

[0056] Figure 18c This diagram illustrates another current flow direction under the control method according to an example embodiment of this application.

[0057] Figure 18d This diagram illustrates another current flow direction under the control method according to an example embodiment of this application.

[0058] Figure 18e This diagram illustrates another current flow direction under the control method according to an example embodiment of this application.

[0059] Figure 18f This diagram illustrates another current flow direction under the control method according to an example embodiment of this application.

[0060] Figure 19 A flowchart of another control method according to an example embodiment of this application is shown.

[0061] Figure 20a A schematic diagram showing the current flow direction under the control method according to an example embodiment of this application is shown.

[0062] Figure 20b This diagram illustrates another current flow direction under the control method according to an example embodiment of this application.

[0063] Figure 20c This diagram illustrates another current flow direction under the control method according to an example embodiment of this application.

[0064] Figure 20d This diagram illustrates another current flow direction under the control method according to an example embodiment of this application.

[0065] Figure 20e This diagram illustrates another current flow direction under the control method according to an example embodiment of this application.

[0066] Figure 20f This diagram illustrates another current flow direction under the control method according to an example embodiment of this application. Detailed Implementation

[0067] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0068] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of these specific details, or other methods, components, materials, apparatus, or operations may be employed. In these cases, well-known structures, methods, apparatuses, implementations, materials, or operations will not be shown or described in detail.

[0069] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0070] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0071] The specific embodiments according to this application will now be described in detail with reference to the accompanying drawings.

[0072] Figure 1 This diagram illustrates a current-breaking device according to an example embodiment of the present application, such as... Figure 1 The device shown for interrupting current includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4.

[0073] According to an embodiment of this application, the flow path 1, the transfer path 2, and the oscillation path 3 are connected in parallel.

[0074] According to some embodiments, the current-carrying branch 1 is composed of a mechanical switch and a current-carrying unit connected in series.

[0075] According to some embodiments, the transfer branch 2 is composed of a bidirectional thyristor unit and an active power electronic unit connected in series.

[0076] According to some embodiments, the oscillation branch 3 is composed of an oscillation capacitor, a damping and vibration suppression unit, and an oscillation inductor connected in series.

[0077] According to an embodiment of this application, the energy-consuming branch 4 is connected in parallel with the oscillating capacitor.

[0078] According to some other embodiments, the energy-consuming branch 4 is connected in parallel with the series-connected oscillating capacitor and the damping vibration suppression unit.

[0079] According to some other embodiments, the power-consuming branch 4 is connected in parallel with the series-connected oscillating capacitor and oscillating inductor.

[0080] According to some other embodiments, the energy-consuming branch 4 is connected in parallel with the flow-through branch.

[0081] According to some embodiments, the active power electronic unit is composed of at least one active power electronic module with bypass function connected in series. The active power electronic module with bypass function includes a power electronic switch, an active power electronic module bypass switch, and a voltage source.

[0082] According to other embodiments, the active power electronic unit is composed of at least one active power electronic module with isolation function connected in parallel. The active power electronic module with isolation function includes a power electronic switch, an isolating switch, and a voltage source.

[0083] According to embodiments of this application, the current-carrying unit is composed of at least one bidirectional current-carrying module connected in series and parallel with a current-carrying unit bypass switch; and / or the mechanical switch is composed of one or more mechanical switches connected in series and parallel; and / or the oscillating capacitor is composed of one or more capacitors connected in series and parallel; and / or the oscillating inductor is composed of one or more inductors connected in series and parallel; and / or the energy-dissipating branch is composed of one or more surge arresters connected in series and parallel.

[0084] Figure 2 This diagram illustrates a circuit structure of a current-breaking device according to an example embodiment of this application, as shown below. Figure 2 The current-breaking device shown includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4. The current-carrying branch 1 is connected in parallel with the transfer branch 2 and the oscillation branch 3. The current-carrying branch 1 is composed of a mechanical switch 11 and a current-carrying unit 12 connected in series. The transfer branch 2 is composed of a bidirectional thyristor unit 21 and an active power electronic unit 22 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, a damping and vibration-suppressing unit 32, and an oscillating inductor 33 connected in series. The energy-dissipating branch 4 is connected in parallel with the oscillating capacitor 31. The active power electronic unit 22 is composed of at least one active power electronic module with bypass function connected in series.

[0085] Figure 3 This diagram illustrates another current-breaking device circuit structure according to an example embodiment of this application, such as... Figure 3The current-breaking device shown includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4. The current-carrying branch 1 is connected in parallel with the transfer branch 2 and the oscillation branch 3. The current-carrying branch 1 is composed of a mechanical switch 11 and a current-carrying unit 12 connected in series. The transfer branch 2 is composed of a bidirectional thyristor unit 21 and an active power electronic unit 22 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, a damping and vibration-suppressing unit 32, and an oscillating inductor 33 connected in series. The energy-dissipating branch 4 is connected in parallel with the series-connected oscillating capacitor 31 and damping and vibration-suppressing unit 32. The active power electronic unit 22 is composed of at least one active power electronic module with bypass function connected in series.

[0086] Figure 4 This diagram illustrates another current-breaking device circuit structure according to an example embodiment of this application, such as... Figure 4 The current-breaking device shown includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4. The current-carrying branch 1 is connected in parallel with the transfer branch 2 and the oscillation branch 3. The current-carrying branch 1 is composed of a mechanical switch 11 and a current-carrying unit 12 connected in series. The transfer branch 2 is composed of a bidirectional thyristor unit 21 and an active power electronic unit 22 connected in series. The oscillation branch 3 is composed of an oscillation capacitor 31, a damping and vibration suppression unit 32, and an oscillation inductor 33 connected in series. The energy-dissipating branch 4 is connected in parallel with the oscillation capacitor 31 and the oscillation inductor 33 connected in series. The active power electronic unit 22 is composed of at least one active power electronic module with bypass function connected in series.

[0087] Figure 5 This diagram illustrates another current-breaking device circuit structure according to an example embodiment of this application, such as... Figure 5 The current-breaking device shown includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4. The current-carrying branch 1 is connected in parallel with the transfer branch 2 and the oscillation branch 3. The current-carrying branch 1 is composed of a mechanical switch 11 and a current-carrying unit 12 connected in series. The transfer branch 2 is composed of a bidirectional thyristor unit 21 and an active power electronic unit 22 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, a damping and vibration-suppressing unit 32, and an oscillating inductor 33 connected in series. The energy-dissipating branch 4 is connected in parallel with the current-carrying branch 1. The active power electronic unit 22 is composed of at least one active power electronic module with bypass function connected in series.

[0088] Figure 6 This diagram illustrates another current-breaking device circuit structure according to an example embodiment of this application, such as... Figure 6The current-breaking device shown includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4. The current-carrying branch 1 is connected in parallel with the transfer branch 2 and the oscillation branch 3. The current-carrying branch 1 is composed of a mechanical switch 11 and a current-carrying unit 12 connected in series. The transfer branch 2 is composed of a bidirectional thyristor unit 21 and an active power electronic unit 22 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, a damping and vibration-suppressing unit 32, and an oscillating inductor 33 connected in series. The energy-dissipating branch 4 is connected in parallel with the oscillating capacitor 31. The active power electronic unit 22 is composed of at least one active power electronic module with isolation function connected in parallel.

[0089] Figure 7 This diagram illustrates another current-breaking device circuit structure according to an example embodiment of this application, such as... Figure 7 The current-breaking device shown includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4. The current-carrying branch 1 is connected in parallel with the transfer branch 2 and the oscillation branch 3. The current-carrying branch 1 is composed of a mechanical switch 11 and a current-carrying unit 12 connected in series. The transfer branch 2 is composed of a bidirectional thyristor unit 21 and an active power electronic unit 22 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, a damping and vibration-suppressing unit 32, and an oscillating inductor 33 connected in series. The energy-dissipating branch 4 is connected in parallel with the series-connected oscillating capacitor 31 and damping and vibration-suppressing unit 32. The active power electronic unit 22 is composed of at least one active power electronic module with isolation function connected in parallel.

[0090] Figure 8 This diagram illustrates another current-breaking device circuit structure according to an example embodiment of this application, such as... Figure 8 The current-breaking device shown includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4. The current-carrying branch 1 is connected in parallel with the transfer branch 2 and the oscillation branch 3. The current-carrying branch 1 is composed of a mechanical switch 11 and a current-carrying unit 12 connected in series. The transfer branch 2 is composed of a bidirectional thyristor unit 21 and an active power electronic unit 22 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, a damping unit 32, and an oscillating inductor 33 connected in series. The energy-dissipating branch 4 is connected in parallel with the series-connected oscillating capacitor 31 and oscillating inductor 33. The active power electronic unit 22 is composed of at least one active power electronic module with isolation function connected in parallel.

[0091] Figure 9 This diagram illustrates another current-breaking device circuit structure according to an example embodiment of this application, such as... Figure 9The current-breaking device shown includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4. The current-carrying branch 1 is connected in parallel with the transfer branch 2 and the oscillation branch 3. The current-carrying branch 1 is composed of a mechanical switch 11 and a current-carrying unit 12 connected in series. The transfer branch 2 is composed of a bidirectional thyristor unit 21 and an active power electronic unit 22 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, a damping and vibration-suppressing unit 32, and an oscillating inductor 33 connected in series. The energy-dissipating branch 4 is connected in parallel with the current-carrying branch 1. The active power electronic unit 22 is composed of at least one active power electronic module with isolation function connected in parallel.

[0092] Figure 10a This diagram illustrates a circuit structure of an active power electronic module with bypass function according to an example embodiment of this application. Figure 10a The active power electronic module shown includes a power electronic switch, an active power electronic module bypass switch, and a voltage source. The power electronic switch includes a first power electronic switch and a second power electronic switch; the active power electronic module bypass switch includes a first bypass switch; and the voltage source includes a first voltage source.

[0093] like Figure 10a As shown, the positive terminal of the first power electronic switch is connected to the positive terminal of the first voltage source, the negative terminal of the first power electronic switch is connected to the positive terminal of the second power electronic switch and then an external wire is led out, the negative terminal of the second power electronic switch is connected to the negative terminal of the first voltage source and then an external wire is led out, and the first bypass switch is connected in parallel between the two external wires.

[0094] Figure 10b This diagram illustrates a circuit structure of another active power electronic module with bypass function according to an example embodiment of this application, as shown below. Figure 10b The active power electronic module shown includes a power electronic switch, an active power electronic module bypass switch, and a voltage source. The power electronic switch includes a third, a fourth, a fifth, and a sixth power electronic switch; the active power electronic module bypass switch includes a second bypass switch; and the voltage source includes a second voltage source.

[0095] like Figure 10b As shown, the positive terminal of the third power electronic switch is connected to the positive terminal of the fifth power electronic switch and the positive terminal of the second voltage source, respectively. The negative terminal of the third power electronic switch is connected to the positive terminal of the fourth power electronic switch and then led out with an external wire. The negative terminal of the fourth power electronic switch is connected to the negative terminal of the sixth power electronic switch and the negative terminal of the second voltage source, respectively. The negative terminal of the fifth power electronic switch is connected to the positive terminal of the sixth power electronic switch and then led out with an external wire. The second bypass switch is connected in parallel between the two external wires.

[0096] Figure 10cThis diagram illustrates a circuit structure of another active power electronic module with bypass function according to an example embodiment of this application, as shown below. Figure 10c The active power electronic module shown includes a power electronic switch, an active power electronic module bypass switch, and a voltage source. Specifically, the power electronic switch includes a seventh power electronic switch and an eighth power electronic switch, the active power electronic module bypass switch includes a third bypass switch, and the voltage source includes a third voltage source and a fourth voltage source.

[0097] like Figure 10c As shown, the positive terminal of the seventh power electronic switch is connected to the positive terminal of the third voltage source, the negative terminal of the seventh power electronic switch is connected to the positive terminal of the eighth power electronic switch and then an external wire is led out, the negative terminal of the eighth power electronic switch is connected to the negative terminal of the fourth voltage source, the negative terminal of the third voltage source is connected to the positive terminal of the fourth voltage source and then an external wire is led out, and the third bypass switch is connected in parallel between the two external wires.

[0098] Figures 10a-10c The active power electronic module with bypass function operates in two modes: an off-state mode and an on-state mode. In off-state mode, the bypass switch of the active power electronic module is closed; in on-state mode, the bypass switch is open. To improve the reliability of the current-breaking device, the active power electronic unit of the transfer branch is equipped with redundant modules, i.e., multiple active power electronic modules are configured. When an active power electronic module fails, it is switched from on-state mode to off-state mode, and any other active power electronic module is selected to switch to on-state mode.

[0099] Figure 11a This diagram illustrates a circuit structure of an active power electronic module with isolation functionality according to an example embodiment of this application. Figure 11a The active power electronic module shown includes a power electronic switch, a disconnecting switch, and a voltage source. Specifically, the power electronic switch includes a ninth power electronic switch and a tenth power electronic switch, the disconnecting switch includes a first disconnecting switch, and the voltage source includes a fifth voltage source.

[0100] like Figure 11a As shown, the positive terminal of the ninth power electronic switch is connected to the positive terminal of the fifth voltage source, the negative terminal of the ninth power electronic switch is connected to the positive terminal of the tenth power electronic switch and the first terminal of the first disconnecting switch, the second terminal of the first disconnecting switch is connected to an external wire, and the negative terminal of the tenth power electronic switch is connected to the negative terminal of the fifth voltage source and then connected to an external wire.

[0101] Figure 11b This diagram illustrates a circuit structure of an active power electronic module with isolation functionality according to an example embodiment of this application. Figure 11bThe active power electronic module shown includes a power electronic switch, a disconnecting switch, and a voltage source. Specifically, the power electronic switches include an eleventh, twelfth, thirteenth, and fourteenth power electronic switches; the disconnecting switch includes a second disconnecting switch; and the voltage source includes a sixth voltage source.

[0102] like Figure 11b As shown, the positive terminal of the eleventh power electronic switch is connected to the positive terminal of the thirteenth power electronic switch and the positive terminal of the sixth voltage source, respectively. The negative terminal of the eleventh power electronic switch is connected to the positive terminal of the twelfth power electronic switch and then led out with an external wire. The negative terminal of the twelfth power electronic switch is connected to the negative terminal of the fourteenth power electronic switch and the negative terminal of the sixth voltage source, respectively. The negative terminal of the thirteenth power electronic switch is connected to the positive terminal of the fourteenth power electronic switch and the first terminal of the second disconnecting switch, respectively. The second terminal of the second disconnecting switch leads out with an external wire.

[0103] Figure 11c This diagram illustrates a circuit structure of an active power electronic module with isolation functionality according to an example embodiment of this application. Figure 11c The active power electronic module shown includes a power electronic switch, a disconnecting switch, and a voltage source. Specifically, the power electronic switch includes a fifteenth power electronic switch and a sixteenth power electronic switch, the disconnecting switch includes a third disconnecting switch, and the voltage source includes a seventh voltage source and an eighth voltage source.

[0104] like Figure 11c As shown, the positive terminal of the fifteenth power electronic switch is connected to the positive terminal of the seventh voltage source, the negative terminal of the fifteenth power electronic switch is connected to the positive terminal of the sixteenth power electronic switch and then an external wire is led out, the negative terminal of the sixteenth power electronic switch is connected to the negative terminal of the eighth voltage source, the negative terminal of the seventh voltage source is connected to the positive terminal of the eighth voltage source and the first terminal of the third disconnecting switch respectively, and the second terminal of the third disconnecting switch is led out with an external wire.

[0105] Figures 11a-11c The active power electronic module with isolation function has two operating modes: off mode and on mode. In off mode, the disconnect switch is open; in on mode, the disconnect switch is closed.

[0106] To improve the reliability of the segmented current device, the active power electronic unit of its transfer branch is equipped with redundant modules, that is, multiple active power electronic modules are configured. When an active power electronic module fails, the failed module is switched from the input mode to the output mode, and any other active power electronic module is selected to switch to the input mode.

[0107] According to embodiments of this application, the first power electronic switch, the second power electronic switch, the third power electronic switch, the fourth power electronic switch, the fifth power electronic switch, the sixth power electronic switch, the seventh power electronic switch, the eighth power electronic switch, the ninth power electronic switch, the tenth power electronic switch, the eleventh power electronic switch, the twelfth power electronic switch, the thirteenth power electronic switch, the fourteenth power electronic switch, the fifteenth power electronic switch, and the sixteenth power electronic switch are all composed of at least one level of power semiconductor device. The power semiconductor device includes a fully controlled power semiconductor device or a semi-controlled power semiconductor device. The fully controlled power semiconductor device is one or any combination of IGBT, IEGT, IGCT, MOSFET, and GTO. The semi-controlled power semiconductor device is a thyristor.

[0108] According to some embodiments, the first voltage source, the second voltage source, the third voltage source, the fourth voltage source, the fifth voltage source, the sixth voltage source, the seventh voltage source, and the eighth voltage source are pre-charged capacitors, energy storage batteries, or AC rectified power supplies. In order to protect the voltage sources and prevent overvoltage damage during current shutdown, overvoltage measures, such as surge arresters or chopper circuits, can be connected in parallel across them.

[0109] Figure 12a This diagram illustrates a circuit structure of a bidirectional thyristor unit for a transfer branch according to an example embodiment of this application. Figure 12a The bidirectional thyristor unit shown includes a bidirectional thyristor.

[0110] Figure 12b This diagram illustrates a circuit structure of a bidirectional thyristor unit for a transfer branch according to an example embodiment of this application. Figure 12b The bidirectional thyristor unit shown includes a first unidirectional thyristor and a second unidirectional thyristor, which are connected in parallel in opposite directions.

[0111] According to some embodiments, the current-carrying unit is composed of at least one bidirectional current-carrying module connected in series and parallel, each with a bypass switch connected in parallel. Figures 13a-13d Typical circuit topologies for four different current-carrying units are shown in the diagrams.

[0112] Figure 14a This diagram illustrates a circuit structure of a damping and vibration suppression unit for an oscillation branch according to an example embodiment of this application. Figure 14a The damping and vibration suppression unit shown includes a fifth diode, a sixth diode, and a first vibration suppression capacitor. The positive terminal of the fifth diode is connected to the first end of the first vibration suppression capacitor and then an external wire is led out. The negative terminal of the fifth diode is connected to the positive terminal of the sixth diode and then an external wire is led out. The negative terminal of the sixth diode is connected to the second end of the first vibration suppression diode.

[0113] Figure 14b This diagram illustrates a circuit structure of a damping and vibration suppression unit for an oscillation branch according to an example embodiment of this application. Figure 14b The damping and vibration suppression unit shown includes a seventh diode, an eighth diode, a ninth diode, a tenth diode, and a second vibration suppression capacitor. The seventh, eighth, ninth, and tenth diodes form a diode full bridge. The positive and negative terminals of the DC side of the diode full bridge are connected to the first and second terminals of the second vibration suppression capacitor, respectively. The AC side of the diode full bridge forms two lead-out connection lines.

[0114] To protect the damping and vibration suppression unit from overvoltage damage during current shutdown, according to some embodiments, overvoltage measures, such as surge arresters or chopper circuits, can be connected in parallel across its vibration suppression capacitor.

[0115] According to some embodiments, the mechanical switch is composed of one or more mechanical switches connected in series and parallel. It is usually a fast-acting switch and can employ electromagnetic repulsion, permanent magnet, or explosion principle mechanical switches. When multiple fast switches are connected in series, an RC circuit is usually connected in parallel across each fast switch to improve the voltage equalization performance between the breaks.

[0116] According to some embodiments, the oscillation capacitor of the oscillation branch is composed of one or more capacitors connected in series and parallel, typically a few uf or a dozen uf, with high voltage resistance and small size.

[0117] According to some embodiments, the oscillating inductor of the oscillating branch is composed of one or more inductors connected in series and parallel;

[0118] According to some embodiments, the energy-consuming branch is composed of one or more surge arresters connected in series and parallel.

[0119] Figure 15 This diagram illustrates a module structure block diagram of a current-breaking function according to an example embodiment of this application, such as... Figure 15 The interrupting current module shown is connected in series with multiple interrupting current devices to achieve flexible expansion, in order to meet the application requirements of medium and high voltage systems.

[0120] According to other embodiments of this application, the current-breaking module can also connect internal components of the current-breaking device in series, for example, such as... Figure 16 The current-breaking module shown adopts a modular unit composed of a transfer branch, an oscillation branch, and an energy-consuming branch, which can be flexibly expanded by series connection to meet the application requirements of medium and high voltage systems.

[0121] Figure 17 This diagram illustrates a control method flowchart according to an example embodiment of the present application. Figures 18a-18f This is a schematic diagram of the current flow under the control method according to an example embodiment of this application.

[0122] The following is combined Figures 18a-18f ,right Figure 17 The control method shown will be described in detail.

[0123] In step S1701, the device for interrupting the current receives a command.

[0124] When the system is not faulty, according to the embodiments of this application, in response to the normal operation command of the power system, step S1703 is executed, the current-breaking device is in the initial closed state, that is, the current flows through the current-carrying branch, the mechanical switch of the current-carrying branch is in the closed state, the current-carrying unit is in the current-carrying unit bypass switch closed state, and the current flow direction is as follows: Figure 18a As shown, the active power electronic unit in the input mode of the transfer branch is in a disconnected or blocked state.

[0125] When a system fault occurs, the current-breaking device receives a tripping command. According to some other embodiments of this application, in response to the tripping command received when a power system fault occurs, the current-breaking device executes step S1705. In step S1705, the mechanical switch of the current-carrying branch is opened, and the current-carrying unit bypass switch of the current-carrying unit is opened and the bidirectional current-carrying module is turned on, with the current flow direction as follows: Figure 18b As shown in the diagram, the arc voltage of the bypass switch in the current-carrying unit causes the current to shift to the bidirectional current-carrying mode. According to some embodiments, the bypass switch in this control method is preferably a high arc voltage bypass switch.

[0126] In step S1707, when the bypass switch of the current-carrying unit is switched to the insulation position and the current in the bypass switch is completely transferred to the bidirectional current-carrying module, the bidirectional conducting thyristor unit of the transfer branch is triggered to conduct and the bidirectional current-carrying module of the current-carrying unit is controlled to disconnect, and the current flow direction is as follows: Figure 18c As shown in the image.

[0127] In step S1709, when the mechanical switch is opened to the insulation position, the active power electronic unit controlling the transfer branch outputs a multi-pulse square wave voltage. The output square wave voltage excites the oscillation capacitor and oscillation inductor of the oscillation branch to oscillate, generating an oscillation current with the same amplitude and opposite direction to the fault current. The current flow direction is as follows: Figure 18d , 18e As shown, the alternating oscillation current causes the bidirectional thyristor unit of the transfer branch to experience zero-crossing interruption.

[0128] In step S1711, after the transfer branch current crosses zero, the fault current begins to charge the oscillation capacitor of the oscillation branch. When the voltage of the oscillation capacitor is greater than the residual voltage of the energy-dissipating branch (e.g., the residual voltage of the surge arrester in the energy-dissipating branch), the fault current begins to transfer to the energy-dissipating branch and dissipate to zero. The current flow direction is as follows: Figure 18f As shown in the diagram, the circuit breaker tripped successfully and the tripping operation ended.

[0129] Figure 19 This diagram illustrates another control method according to an example embodiment of the present application. Figures 20a-20f This is a schematic diagram of the current flow under the control method according to an example embodiment of this application.

[0130] In step S1901, the device for interrupting the current receives a command.

[0131] When the system is not faulty, according to the embodiments of this application, in response to the normal operation command of the power system, step S1903 is executed, the current-breaking device is in the initial closed state, that is, the current flows through the current-carrying branch, the mechanical switch of the current-carrying branch is in the closed state, the current-carrying unit is in the current-carrying unit bypass switch open state and the bidirectional current-carrying module is in the conducting state, and the current flow direction is as follows. Figure 20a As shown, the active power electronic unit in the input mode of the transfer branch is in a disconnected or blocked state.

[0132] When a system fault occurs, the current-breaking device receives a tripping command. According to some other embodiments of this application, in response to the tripping command received when a power system fault occurs, the current-breaking device executes step S1905.

[0133] In step S1905, the bidirectional conducting thyristor unit of the trigger transfer branch is turned on, and the bidirectional current-carrying module of the current-carrying unit is turned off, with the current flow direction as follows: Figure 20b As shown in the image.

[0134] In step S1907, after the current has completely transferred from the current-carrying branch to the transfer branch, the mechanical switch is opened without arcing, and the current flows as follows: Figure 20c As shown in the image.

[0135] In step S1909, when the mechanical switch is opened to the insulation position, the active power electronic unit controlling the transfer branch outputs a multi-pulse square wave voltage. The output square wave voltage excites the oscillation capacitor and oscillation inductor of the oscillation branch to oscillate, generating an oscillation current with the same amplitude and opposite direction to the fault current. The current flow direction is as follows: Figure 20d , 20e As shown in the diagram, the oscillating current causes the bidirectional thyristor unit of the transfer branch to experience zero-crossing interruption.

[0136] In step S1911, after the transfer branch current crosses zero, the fault current begins to charge the oscillating capacitor of the oscillating branch. When the voltage of the oscillating capacitor is greater than the residual voltage of the energy-dissipating branch (e.g., the residual voltage of the surge arrester in the energy-dissipating branch), the fault current begins to transfer to the energy-dissipating branch and dissipate to zero. The current flow direction is as follows: Figure 20f As shown in the diagram, the circuit breaker tripped successfully and the tripping operation ended.

[0137] According to an embodiment of this application, the frequency of the square wave voltage output by the active power electronic unit is similar to the resonant frequency of the oscillating capacitor and the oscillating inductor. The excitation of the square wave voltage can generate a current with a continuously increasing current amplitude.

[0138] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. Furthermore, any changes or modifications made by those skilled in the art based on the ideas of this application, and on the specific implementation methods and application scope of this application, are all within the scope of protection of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A device for interrupting current, characterized in that, The current-breaking device includes a current-carrying branch, a transfer branch, an oscillation branch, and an energy-dissipating branch, wherein, The flow branch is connected in parallel with the transfer branch and the oscillation branch; The flow path is composed of a mechanical switch and a flow unit connected in series. The transfer branch is composed of a bidirectional thyristor unit and an active power electronic unit connected in series; The oscillation branch is composed of an oscillation capacitor, a damping unit, and an oscillation inductor connected in series. The energy-consuming branch is connected in parallel with the oscillating capacitor, or in parallel with the oscillating capacitor and the damping vibration suppression unit connected in series, or in parallel with the oscillating capacitor and the oscillating inductor connected in series, or in parallel with the current-carrying branch. The device transfers the current from the current-carrying branch to the transfer branch, and then generates an oscillating current with the same amplitude and opposite direction as the fault current by outputting a square wave voltage oscillation through the active power electronic unit, so that the transfer branch crosses zero and disconnects naturally.

2. The current-breaking device as described in claim 1, characterized in that, The active power electronic unit is composed of at least one active power electronic module with bypass function connected in series, wherein, The active power electronic module with bypass function includes a power electronic switch, an active power electronic module bypass switch, and a voltage source. The power electronic switch includes a first power electronic switch and a second power electronic switch. The active power electronic module bypass switch includes a first bypass switch. The voltage source includes a first voltage source. The positive terminal of the first power electronic switch is connected to the positive terminal of the first voltage source. The negative terminal of the first power electronic switch is connected to the positive terminal of the second power electronic switch and then led out with an external wire. The negative terminal of the second power electronic switch is connected to the negative terminal of the first voltage source and then led out with an external wire. The first bypass switch is connected in parallel between the two external wires. The active power electronic module with bypass function includes a power electronic switch, an active power electronic module bypass switch, and a voltage source. The power electronic switch includes a third, fourth, fifth, and sixth power electronic switch. The active power electronic module bypass switch is a second bypass switch. The voltage source includes a second voltage source. The positive terminal of the third power electronic switch is connected to the positive terminals of the fifth power electronic switch and the second voltage source, respectively. The negative terminal of the third power electronic switch is connected to the positive terminal of the fourth power electronic switch and then led out with an external wire. The negative terminal of the fourth power electronic switch is connected to the negative terminals of the sixth power electronic switch and the second voltage source, respectively. The negative terminal of the fifth power electronic switch is connected to the positive terminal of the sixth power electronic switch and then led out with an external wire. The second bypass switch is connected in parallel between the two external wires. The active power electronic module with bypass function includes a power electronic switch, an active power electronic module bypass switch, and a voltage source. The power electronic switch includes a seventh power electronic switch and an eighth power electronic switch. The active power electronic module bypass switch includes a third bypass switch. The voltage source includes a third voltage source and a fourth voltage source. The positive terminal of the seventh power electronic switch is connected to the positive terminal of the third voltage source. The negative terminal of the seventh power electronic switch is connected to the positive terminal of the eighth power electronic switch and then led out with an external wire. The negative terminal of the eighth power electronic switch is connected to the negative terminal of the fourth voltage source. The negative terminal of the third voltage source is connected to the positive terminal of the fourth voltage source and then led out with an external wire. The third bypass switch is connected in parallel between the two external wires.

3. The current-breaking device as described in claim 2, characterized in that, The operating modes of the active power electronic module with bypass function include an off mode and an on mode. In the exit mode, the active power electronic module bypass switch is closed; In the input mode, the bypass switch of the active power electronic module is turned on.

4. The current-breaking device as described in claim 1, characterized in that, The active power electronic unit is composed of at least one active power electronic module with isolation function connected in parallel, wherein, The active power electronic module with isolation function includes a power electronic switch, an isolating switch, and a voltage source. The power electronic switch includes a ninth power electronic switch and a tenth power electronic switch. The isolating switch includes a first isolating switch. The voltage source includes a fifth voltage source. The positive terminal of the ninth power electronic switch is connected to the positive terminal of the fifth voltage source. The negative terminal of the ninth power electronic switch is connected to the positive terminal of the tenth power electronic switch and the first terminal of the first isolating switch. An external wire is led out from the second terminal of the first isolating switch. The negative terminal of the tenth power electronic switch is connected to the negative terminal of the fifth voltage source and then led out. The active power electronic module with isolation function includes a power electronic switch, an isolating switch, and a voltage source. The power electronic switch includes an eleventh, twelfth, thirteenth, and fourteenth power electronic switches. The isolating switch includes a second isolating switch. The voltage source includes a sixth voltage source. The positive terminal of the eleventh power electronic switch is connected to the positive terminals of the thirteenth and sixth voltage sources. The negative terminal of the eleventh power electronic switch is connected to the positive terminal of the twelfth power electronic switch and then led out with an external wire. The negative terminal of the twelfth power electronic switch is connected to the negative terminals of the fourteenth and sixth voltage sources. The negative terminal of the thirteenth power electronic switch is connected to the positive terminal of the fourteenth power electronic switch and the first terminal of the second isolating switch. The second terminal of the second isolating switch leads out with an external wire. The active power electronic module with isolation function includes a power electronic switch, an isolating switch, and a voltage source. The power electronic switch includes a fifteenth power electronic switch and a sixteenth power electronic switch. The isolating switch includes a third isolating switch. The voltage source includes a seventh voltage source and an eighth voltage source. The positive terminal of the fifteenth power electronic switch is connected to the positive terminal of the seventh voltage source. The negative terminal of the fifteenth power electronic switch is connected to the positive terminal of the sixteenth power electronic switch and then led out with an external wire. The negative terminal of the sixteenth power electronic switch is connected to the negative terminal of the eighth voltage source. The negative terminal of the seventh voltage source is connected to the positive terminal of the eighth voltage source and the first terminal of the third isolating switch. The second terminal of the third isolating switch leads out with an external wire.

5. The current-breaking device as described in claim 4, characterized in that, The operating modes of the active power electronic module with isolation function include an off mode and an on mode. In the exit mode, the isolation switch is open; In the input mode, the disconnect switch is closed.

6. The current-breaking device as described in claim 1, characterized in that, The bidirectional thyristor unit includes a bidirectional thyristor; or The bidirectional thyristor unit includes a first unidirectional thyristor and a second unidirectional thyristor, which are connected in parallel in opposite directions.

7. The current-breaking device as described in claim 1, characterized in that, The damping and vibration suppression unit includes a fifth diode, a sixth diode, a first vibration suppression diode, and a first vibration suppression capacitor. The positive terminal of the fifth diode is connected to the first terminal of the first vibration suppression capacitor and then led out with an external wire. The negative terminal of the fifth diode is connected to the positive terminal of the sixth diode and then led out with an external wire. The negative terminal of the sixth diode is connected to the second terminal of the first vibration suppression diode; or The damping and vibration suppression unit includes a seventh diode, an eighth diode, a ninth diode, a tenth diode, and a second vibration suppression capacitor. The seventh diode, the eighth diode, the ninth diode, and the tenth diode form a diode full bridge. The positive and negative terminals of the DC side of the diode full bridge are connected to the first and second terminals of the second vibration suppression capacitor, respectively. The AC side of the diode full bridge forms two lead-out connection lines.

8. The current-breaking device as described in claim 1, characterized in that, The current-passing unit is composed of at least one bidirectional current-passing module connected in series and parallel, each equipped with a current-passing unit bypass switch; and / or The mechanical switch is composed of one or more mechanical switches connected in series or parallel; and / or The oscillating capacitor is composed of one or more capacitors connected in series and parallel; and / or The oscillating inductor is composed of one or more inductors connected in series and parallel; and / or The energy-consuming branch is composed of one or more surge arresters connected in series and parallel.

9. The current-breaking device according to any one of claims 2-5, characterized in that, The power electronic switch is composed of at least one stage of power semiconductor devices connected in series. These power semiconductor devices include fully controlled or semi-controlled power semiconductor devices. The fully controlled power semiconductor devices are one or any combination of IGBT, IEGT, IGCT, MOSFET, and GTO. The semi-controlled power semiconductor devices are thyristors; and / or The voltage source is a pre-charged capacitor, an energy storage battery, or an AC rectified power supply.

10. A current-breaking module, characterized in that, The current-breaking module includes at least two current-breaking devices as described in any one of claims 1-9, and the current-breaking devices are connected in series.

11. A control method, characterized in that, The control method is used to control the device for interrupting current as claimed in any one of claims 1-9, the control method comprising: In response to the system's normal operation command, current flows through the current-carrying branch, the mechanical switch of the current-carrying branch is in the closed state, the current-carrying unit is in the current-carrying unit bypass switch closed state, and the active power electronic unit in the transfer branch's input mode is in the disconnected state or locked state. In response to a trip command received when a system failure occurs, Open the mechanical switch of the current-passing branch, and control the current-passing unit bypass switch of the current-passing unit to open and the bidirectional current-passing module to be turned on; When the bypass switch of the current-carrying unit is switched to the insulation position and the current in the bypass switch of the current-carrying unit is completely transferred to the bidirectional current-carrying module, the bidirectional thyristor unit of the transfer branch is triggered to conduct and the bidirectional current-carrying module of the current-carrying unit is controlled to disconnect. When the mechanical switch is separated to the insulation position, the active power electronic unit controlling the transfer branch outputs a multi-pulse square wave voltage. The output square wave voltage excites the oscillating capacitor and oscillating inductor of the oscillating branch to oscillate, generating an oscillating current with the same amplitude and opposite direction as the fault current. The oscillating current causes the bidirectional thyristor unit of the transfer branch to experience a zero-crossing disconnection. When the current in the transfer branch crosses zero, the fault current begins to charge the oscillation capacitor in the oscillation branch. When the voltage of the oscillation capacitor is greater than the residual voltage of the energy-consuming branch, the fault current is transferred to the energy-consuming branch and dissipated to zero, the circuit breaker trips successfully and the tripping operation ends.

12. A control method, characterized in that, The control method is used to control the device for interrupting current as claimed in any one of claims 1-9, the control method comprising: In response to the system's normal operation command, current flows through the current-carrying branch, the mechanical switch of the current-carrying branch is in the closed state, the current-carrying unit is in the current-carrying unit bypass switch open state and the bidirectional current-carrying module is in the conducting state, and the active power electronic unit in the transfer branch's input mode is in the disconnected state or the locked state. In response to a tripping command received when a system fault occurs, the bidirectional thyristor unit of the transfer branch is triggered to conduct, and the bidirectional current-carrying module of the current-carrying unit is controlled to disconnect. Once the current has been completely transferred from the current-carrying branch to the transfer branch, the mechanical switch opens without arcing. When the mechanical switch is separated to the insulation position, the active power electronic unit controlling the transfer branch outputs a multi-pulse square wave voltage. The output square wave voltage excites the oscillation capacitor and oscillation inductor of the oscillation branch to oscillate, generating an oscillation current with the same amplitude and opposite direction as the fault current. The oscillation current causes the bidirectional thyristor unit of the transfer branch to experience a zero-crossing disconnection. When the current in the transfer branch crosses zero, the fault current begins to charge the oscillation capacitor in the oscillation branch. When the voltage of the oscillation capacitor is greater than the residual voltage of the energy-consuming branch, the fault current begins to transfer to the energy-consuming branch and dissipates to zero, the circuit breaker trips successfully and the tripping operation ends.

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