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 bidirectional conducting thyristor units connected in series. The oscillation branch is composed of an oscillating capacitor, an oscillating inductor, and an active power electronic unit connected in series. The energy-dissipating branch is connected in parallel with the oscillating capacitor, or in parallel with the oscillating capacitor and the active power electronic 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, the mechanical switch of the current breaking device provides reliable breaking, short breaking time for small currents, high module 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 interruption device, a current interruption 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. Among them, 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 and require a long time to interrupt small current conditions. They also 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. Due to their high current-carrying losses, all-solid-state DC circuit breakers are generally not chosen for fault isolation and recovery. The inventors have discovered that in AC applications, conventional AC circuit breakers can only interrupt current by naturally extinguishing at the current zero-crossing point. The large peak value of the first half-wave fault current can adversely affect certain sensitive or critical equipment, necessitating an AC circuit breaker capable of rapidly interrupting current in advance. Summary of the Invention

[0003] This application provides a current breaking device, a current breaking module, and a control method to solve the problems of high risk of mechanical switch reignition, long breaking time for small currents, significant system oscillation, and high equipment cost in existing DC circuit breakers, as well as the impact of high amplitude fault current in the first half-wave of AC circuit breakers on sensitive or important equipment during breaking.

[0004] According to one aspect of this application, a current interruption device is proposed, comprising a current-carrying branch, a transfer branch, an oscillation branch, and an energy-dissipating branch, wherein 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 bidirectional conducting thyristor units connected in series; the oscillation branch is composed of an oscillating capacitor, an oscillating inductor, and an active power electronic unit connected in series; the energy-dissipating branch is connected in parallel with the oscillating capacitor, or in parallel with the oscillating capacitor and the active power electronic 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.

[0005] 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, wherein 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, and the first bypass switch is connected in parallel between the two external leads; or

[0006] 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 includes 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.

[0007] 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.

[0008] According to some embodiments, the operating modes of the active power electronic module with bypass function include an exit mode and an operation mode, wherein in the exit mode, the bypass switch of the active power electronic module is closed; and in the operation mode, the bypass switch of the active power electronic module is open.

[0009] 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, wherein 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 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; or

[0010] 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.

[0011] 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.

[0012] According to some embodiments, the operating modes of the active power electronic module with isolation function include an off mode and an on mode, wherein in the off mode, the isolation switch is open; and in the on mode, the isolation switch is closed.

[0013] According to some embodiments, the bidirectional thyristor unit includes a bidirectional thyristor; or

[0014] The bidirectional thyristor unit includes a first unidirectional thyristor and a second unidirectional thyristor, which are connected in parallel in opposite directions.

[0015] 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.

[0016] 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.

[0017] According to one aspect of this application, a current interruption module is proposed, the current interruption module comprising at least two current interruption devices as described in any of the preceding embodiments, and the current interruption devices being connected in series.

[0018] According to one aspect of this application, a control method is proposed for controlling a current interruption device as described in any of the preceding embodiments. The control method includes, in response to a system normal operation command, current flowing through a current-carrying branch, the mechanical switch of the current-carrying branch being in a closed state, the current-carrying unit being in a current-carrying unit bypass switch closed state, and the active power electronic unit in the oscillation branch's activation mode being in a locked or disconnected state; in response to a tripping command received when a system fault occurs, opening the mechanical switch of the current-carrying branch and controlling the current-carrying unit's current-carrying unit to open and the bidirectional current-carrying module to conduct; triggering a tripping device when the current-carrying unit's current-carrying unit's current-carrying unit's current-carrying unit is separated to the insulation position and the current in the current-carrying unit's current-carrying unit's bypass switch is completely transferred to the bidirectional current-carrying module. The bidirectional thyristor unit of the transfer branch is turned on and the bidirectional current-carrying module of the current-carrying unit is turned off. When the mechanical switch is opened to the insulation position, the active power electronic unit of the oscillation branch is controlled to output 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 break at a zero-crossing point. When the current of the transfer branch crosses zero, the fault current is used to charge the oscillation capacitor of the oscillation branch. When the voltage of the oscillation capacitor is greater than the residual voltage of the surge arrester of the energy-dissipating branch, the fault current is transferred to the energy-dissipating branch and dissipated to zero. The tripping is successful and the tripping operation ends.

[0019] According to one aspect of this application, a control method is proposed for controlling a current-breaking device as described above. The control method includes, in response to a system normal operation command, current flowing through a current-carrying branch, wherein 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 oscillation branch's input mode is in a locked or disconnected 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; after the current has completely transferred from the current-carrying branch to the transfer branch, no... The mechanical switch is opened by an arc. When the mechanical switch is opened to the insulation position, the active power electronic unit of the oscillation 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 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 charges the oscillation capacitor of the oscillation branch. When the voltage of the oscillation capacitor is greater than the residual voltage of the surge arrester in the energy dissipation branch, the fault current is transferred to the energy dissipation branch and dissipated to zero. The circuit breaker trips successfully and the tripping operation ends.

[0020] According to the embodiments of this application, when the current breaking device 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 large-scale promotion and application in AC / DC power transmission and distribution systems.

[0021] 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.

[0022] 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

[0023] 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.

[0024] Figure 1 A structural block diagram of a current interruption device according to an example embodiment of this application is shown.

[0025] Figure 2 A schematic diagram of the circuit structure of a current interruption device according to an example embodiment of this application is shown.

[0026] Figure 3 A schematic diagram of the circuit structure of another current interruption device according to an example embodiment of this application is shown.

[0027] Figure 4 A schematic diagram of the circuit structure of another current interruption device according to an example embodiment of this application is shown.

[0028] Figure 5 A schematic diagram of the circuit structure of another current interruption device according to an example embodiment of this application is shown.

[0029] Figure 6 A schematic diagram of the circuit structure of another current interruption device according to an example embodiment of this application is shown.

[0030] Figure 7 A schematic diagram of the circuit structure of another current interruption device according to an example embodiment of this application is shown.

[0031] Figure 8 A schematic diagram of the circuit structure of another current interruption device according to an example embodiment of this application is shown.

[0032] Figure 9 A schematic diagram of the circuit structure of another current interruption device according to an example embodiment of this application is shown.

[0033] 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.

[0034] Figure 10b This diagram illustrates the circuit structure of an active power electronic module with bypass function according to an example embodiment of this application.

[0035] Figure 10c This diagram illustrates the circuit structure of an active power electronic module with bypass function according to an example embodiment of this application.

[0036] Figure 11a This diagram illustrates the circuit structure of an active power electronic module with isolation functionality according to an example embodiment of this application.

[0037] Figure 11bThis diagram illustrates the circuit structure of an active power electronic module with isolation functionality according to an example embodiment of this application.

[0038] Figure 11c This diagram illustrates the circuit structure of an active power electronic module with isolation functionality according to an example embodiment of this application.

[0039] 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.

[0040] 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.

[0041] Figure 13a A schematic diagram of the circuit structure of the current-carrying unit of the current-carrying branch according to an example embodiment of this application is shown.

[0042] Figure 13b This diagram illustrates another circuit structure of the current-carrying unit of a current-carrying branch according to an example embodiment of this application.

[0043] Figure 13c This diagram illustrates another circuit structure of the current-carrying unit of a current-carrying branch according to an example embodiment of this application.

[0044] Figure 13d This diagram illustrates another circuit structure of the current-carrying unit of a current-carrying branch according to an example embodiment of this application.

[0045] Figure 14 A block diagram of a current interruption module structure according to an example embodiment of this application is shown.

[0046] Figure 15 This diagram illustrates another current interruption module structure according to an example embodiment of the present application.

[0047] Figure 16 A flowchart of a control method according to an example embodiment of this application is shown.

[0048] Figure 17a A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0049] Figure 17b A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0050] Figure 17c A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0051] Figure 17d A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0052] Figure 17e A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0053] Figure 17f A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0054] Figure 18 A flowchart of another control method according to an example embodiment of this application is shown.

[0055] Figure 19a A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0056] Figure 19b A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0057] Figure 19c A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0058] Figure 19d A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0059] Figure 19e A schematic diagram showing the current flow according to an example embodiment of this application is provided.

[0060] Figure 19f A schematic diagram showing the current flow according to an example embodiment of this application is provided. Detailed Implementation

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] The specific embodiments according to this application will now be described in detail with reference to the accompanying drawings.

[0066] Figure 1 This diagram illustrates a structural block diagram of a current interruption device according to an example embodiment of this application, such as... Figure 1 The current interruption device shown includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and an energy-dissipating branch 4.

[0067] According to an embodiment of this application, the flow path 1, the transfer path 2, and the oscillation path 3 are connected in parallel.

[0068] According to some embodiments, the current-carrying branch 1 is composed of a mechanical switch and a current-carrying unit connected in series.

[0069] According to some embodiments, the transfer branch 2 is composed of bidirectional thyristor units connected in series.

[0070] According to some embodiments, the oscillation branch 3 is composed of an oscillation capacitor, an oscillation inductor, and an active power electronic unit connected in series.

[0071] According to an embodiment of this application, the energy-consuming branch 4 is connected in parallel with the oscillating capacitor.

[0072] According to other embodiments, the power-consuming branch 4 is connected in parallel with the series-connected oscillating capacitor and the active power electronic unit.

[0073] According to some other embodiments, the power-consuming branch 4 is connected in parallel with the series-connected oscillating capacitor and oscillating inductor.

[0074] According to some other embodiments, the energy-consuming branch 4 is connected in parallel with the flow-through branch 1.

[0075] 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.

[0076] 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, a disconnect switch, and a voltage source.

[0077] It should be noted that the power electronic switch in the active power electronic unit is composed of at least one stage of power semiconductor devices, including fully controlled power semiconductor devices or semi-controlled power semiconductor devices. Among them, the fully controlled power semiconductor devices are one or any combination of IGBT, IEGT, IGCT, MOSFET, and GTO, while the semi-controlled power semiconductor devices are thyristors.

[0078] The voltage source in an active power electronic unit is a pre-charged capacitor, a storage battery, or an AC rectifier. To protect the voltage source and prevent overvoltage damage during current shutdown, according to some embodiments, overvoltage measures, such as surge arresters or chopper circuits, can be connected in parallel across the voltage source.

[0079] According to an embodiment 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 connected in parallel.

[0080] According to some embodiments, the mechanical switch is composed of one or more mechanical switches connected in series and parallel. It is typically a fast-acting switch, which may employ electromagnetic repulsion, permanent magnet, or explosive principles. According to some embodiments, when multiple fast switches are connected in series, an RC circuit is typically connected in parallel across each fast switch to improve voltage equalization between the contacts.

[0081] In some embodiments, the oscillation capacitor of the oscillation branch is composed of one or more capacitors connected in series and parallel. The oscillation capacitor is typically a few µF or a dozen µF, with high voltage withstand and small size.

[0082] According to some embodiments, the oscillating inductor of the oscillating branch is composed of one or more inductors connected in series and parallel;

[0083] According to some embodiments, the energy-consuming branch is composed of one or more surge arresters connected in series and parallel.

[0084] According to the embodiments of this application, when the current breaking device trips, by controlling the operating states 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 large-scale promotion and application in AC / DC power transmission and distribution systems.

[0085] 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.

[0086] 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.

[0087] Figure 2 This diagram illustrates a circuit structure of a current interruption device according to an example embodiment of this application, such as... Figure 2 The current interrupting 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 bidirectional thyristor units 21 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, an active power electronic unit (including at least two active power electronic modules 32), and an oscillating inductor 33 connected in series. The energy-dissipating branch 4 is connected in parallel with the oscillation capacitor 31. The active power electronic unit 32 is composed of at least one active power electronic module with bypass function connected in series.

[0088] Figure 3 A circuit structure schematic diagram of another current interruption device according to an example embodiment of this application is shown, such as... Figure 3 The current interruption device 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 bidirectional thyristor units 21 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, an active power electronic unit, 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 the active power electronic unit. The active power electronic unit is composed of at least one active power electronic module 32 with bypass function connected in series.

[0089] Figure 4 A circuit structure schematic diagram of another current interruption device according to an example embodiment of this application is shown, such as... Figure 4 The current interruption device 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 bidirectional thyristor units 21 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, an active power electronic unit, 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 is composed of at least one active power electronic module 32 with bypass function connected in series.

[0090] Figure 5 A circuit structure schematic diagram of another current interruption device according to an example embodiment of this application is shown, such as... Figure 5 The current interruption device 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 connected in series. The oscillation branch 3 is composed of an oscillation capacitor 31, an active power electronic unit, and an oscillation 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 is composed of at least one active power electronic module 32 with bypass function connected in series.

[0091] Figure 6 A circuit structure schematic diagram of another current interruption device according to an example embodiment of this application is shown, such as... Figure 6 The current interruption device 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 bidirectional conducting thyristor units 21 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, an active power electronic unit, 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 is composed of at least one active power electronic module 32 with isolation function connected in parallel.

[0092] Figure 7 A circuit structure schematic diagram of another current interruption device according to an example embodiment of this application is shown, such as... Figure 7The current interruption device 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 bidirectional conducting thyristor units 21 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, an active power electronic unit (including at least two active power electronic modules 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 the active power electronic unit. The active power electronic unit is composed of at least one active power electronic module with isolation function connected in parallel.

[0093] Figure 8 A circuit structure schematic diagram of another current interruption device according to an example embodiment of this application is shown, such as... Figure 8 The current interruption device 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 bidirectional thyristor units 21 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, an active power electronic unit, 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 is composed of at least one active power electronic module 32 with isolation function connected in parallel.

[0094] Figure 9 A circuit structure schematic diagram of another current interruption device according to an example embodiment of this application is shown, such as... Figure 9 The current interruption device 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 bidirectional thyristor units 21 connected in series. The oscillation branch 3 is composed of an oscillating capacitor 31, an active power electronic unit, 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 is composed of at least one active power electronic module 32 with isolation function connected in parallel.

[0095] 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. The voltage source includes a first voltage source.

[0096] 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.

[0097] Figure 10b This diagram illustrates a circuit structure of an active power electronic module with bypass function according to an example embodiment of this application. 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 power electronic switch, a fourth power electronic switch, a fifth power electronic switch, 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.

[0098] 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.

[0099] Figure 10c This diagram illustrates a circuit structure of an active power electronic module with bypass function according to an example embodiment of this application. Figure 10c 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 switches include 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.

[0100] 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.

[0101] According to the embodiments of this application, Figures 10a-10cThe operating modes of the active power electronic module with bypass function include an off mode and an on mode. In off mode, the bypass switch of the active power electronic module is closed; in on mode, the bypass switch of the active power electronic module is open.

[0102] To improve the reliability of the current shutdown device, redundant modules are configured in the active power electronic unit module of the transfer branch, that is, multiple active power electronic modules are configured. When an active power electronic module fails, the failed active power electronic 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.

[0103] 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. 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.

[0104] 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.

[0105] 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 11b The active power electronic module shown includes a power electronic switch, a disconnecting switch, and a voltage source. The power electronic switch includes an eleventh power electronic switch, a twelfth power electronic switch, a thirteenth power electronic switch, and a fourteenth power electronic switch. The disconnecting switch includes a second disconnecting switch, and the voltage source includes a sixth voltage source.

[0106] 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.

[0107] Figure 11cThis 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, 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, and the voltage source includes a seventh voltage source and an eighth voltage source.

[0108] 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.

[0109] According to the embodiments of this application, Figure 11a , 11b The active power electronic module with isolation function in I1c has two operating modes: an off mode and an on mode. In off mode, the isolating switch is open; in on mode, the isolating switch is closed.

[0110] To improve the reliability of the current shutdown device, redundant modules are configured in the active power electronic unit module of the transfer branch, that is, multiple active power electronic modules are configured. When any of the multiple active power electronic modules fails, the failed active power electronic 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.

[0111] 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 stage of power semiconductor devices. 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, and the semi-controlled power semiconductor devices are thyristors.

[0112] According to embodiments of this application, 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 their terminals.

[0113] 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 shown includes a bidirectional thyristor.

[0114] 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 shown includes a first unidirectional thyristor and a second unidirectional thyristor, which are connected in parallel in opposite directions.

[0115] According to some embodiments, the current-carrying unit is composed of at least one bidirectional current-carrying module connected in series and parallel, each having a current-carrying unit bypass switch connected in parallel. Figures 13a-13d Typical circuit topologies for four types of current-carrying units are shown respectively.

[0116] According to some embodiments, the mechanical switch is composed of one or more mechanical switches connected in series and parallel, typically a fast-acting switch, which may employ electromagnetic repulsion, permanent magnet, or explosion principle mechanical switches. According to some embodiments, when multiple fast switches are connected in series, an RC circuit is typically connected in parallel across each fast switch to improve the voltage equalization performance between the contacts.

[0117] 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.

[0118] According to some embodiments, the oscillating inductor of the oscillating branch is composed of one or more inductors connected in series and parallel;

[0119] According to some embodiments, the energy-consuming branch is composed of one or more surge arresters connected in series and parallel.

[0120] Figure 14 This diagram illustrates a current interruption module structure according to an example embodiment of this application, such as... Figure 14 The current breaking module shown adopts a series connection of multiple current breaking devices to achieve flexible expansion, so as to meet the application requirements of medium and high voltage systems.

[0121] According to other embodiments of this application, the current interruption module can also connect the internal components of the current interruption device in series, for example, such as Figure 15 The current interruption module shown adopts a modular unit consisting of a transfer branch, an oscillation branch, and an energy dissipation branch, which is flexibly expanded by being connected in series to meet the application requirements of medium and high voltage systems.

[0122] Figure 16 This diagram illustrates a control method flowchart according to an example embodiment of the present application. Figures 17a-17f A schematic diagram illustrating the current flow according to an example embodiment of this application is shown below. Figures 17a-17f ,right Figure 16 The control method shown will be described in detail.

[0123] In step S1601, the current interruption device 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 S1603 is executed, the current disconnecting device is in the initial closed position, 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 17a As shown, the active power electronic unit in the oscillation branch's input mode is either in a locked or disconnected state.

[0125] When a system failure occurs, the current disconnecting device receives a tripping command. According to some other embodiments of this application, the current disconnecting device responds to the tripping command received when the power system failure occurs by executing step S1605.

[0126] In step S1605, the mechanical switch of the current-carrying branch is opened, and the 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 17b 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 the current-carrying unit is preferably a high arc voltage bypass switch.

[0127] In step S1607, 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 17c As shown.

[0128] In step S1609, when the mechanical switch is opened to the insulation position, the active power electronic unit controlling the oscillation 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 17d , 17e As shown, the alternating oscillation current causes the bidirectional thyristor unit of the transfer branch to experience zero-crossing interruption.

[0129] In step S1611, after the current in the transfer branch crosses zero, the fault current begins to charge the oscillating capacitor in the oscillating branch. When the voltage of the oscillating capacitor is greater than the residual voltage of the surge arrester in the energy-dissipating branch, the fault current begins to transfer to the energy-dissipating branch and dissipates to zero. The current flow direction is as follows: Figure 17f As shown, the circuit breaker tripped successfully and the tripping operation ended.

[0130] Figure 18 This diagram illustrates another control method according to an example embodiment of the present application. Figures 19a-19f A schematic diagram illustrating the current flow according to an example embodiment of this application is shown below. Figures 19a-19f ,right Figure 18 The control method shown will be described in detail.

[0131] In step S1801, the current interruption device receives a command.

[0132] 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 S1803 is executed, the current disconnecting 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 19a As shown, the active power electronic unit in the oscillation branch's input mode is in a locked or disconnected state. When a system fault occurs, the current disconnecting device receives a tripping command. According to some other embodiments of this application, the current disconnecting device responds to the tripping command received when a power system fault occurs and executes step S1805.

[0133] In step S1805, 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 19b As shown in the image.

[0134] In step S1807, 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 19c As shown.

[0135] In step S1809, when the mechanical switch is opened to the insulation position, the active power electronic unit controlling the oscillation 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 19d , 19eAs shown, the alternating oscillation current causes the bidirectional thyristor unit of the transfer branch to experience zero-crossing interruption.

[0136] In step S1811, 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 surge arrester in the energy dissipation branch, the fault current begins to transfer to the energy dissipation branch and dissipates to zero. The current flow direction is as follows: Figure 19f As shown, the circuit breaker tripped successfully and the tripping operation ended.

[0137] According to some embodiments, 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 oscillating inductor, and the current with continuously increasing amplitude can be generated by the excitation of the square wave voltage.

[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 current interruption device, characterized in that, The current interruption 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 bidirectional thyristor units connected in series; The oscillation branch is composed of an oscillation capacitor, an oscillation inductor, and an active power electronic unit connected in series; The energy-consuming branch is connected in parallel with the oscillating capacitor, or in parallel with the oscillating capacitor and the active power electronic 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 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 includes 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.

2. The current interruption device as described in claim 1, 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 bypass switch of the active power electronic module is closed; In the input mode, the bypass switch of the active power electronic module is turned on.

3. The current interruption 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; or 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.

4. The current interruption device as described in claim 3, 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.

5. The current interruption 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.

6. The current interruption 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.

7. The current interrupting device as described in any one of claims 1-3, 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.

8. A current interruption module, characterized in that, The current interruption module includes at least two current interruption devices as described in any one of claims 1-7, and the current interruption devices are connected in series.

9. A control method, characterized in that, The control method is used to control the current interruption device as described in any one of claims 1-7, and the control method includes: 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 oscillation branch's input mode is in the locked state or disconnected state. In response to a tripping command received when a system failure 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 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 oscillation 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 is used to charge the oscillation capacitor in the oscillation branch. When the voltage of the oscillation capacitor is greater than the residual voltage of the surge arrester in 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.

10. A control method, characterized in that, The control method is used to control the current interruption device as described in any one of claims 1-7, and the control method includes: 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 oscillation branch's input mode is in the locked state or the disconnected state. In response to a trip 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 an arc. When the mechanical switch is separated to the insulation position, the active power electronic unit controlling the oscillation 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 charges the oscillation capacitor in the oscillation branch. When the voltage of the oscillation capacitor is greater than the residual voltage of the surge arrester in 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.

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