CN115912250A

CN115912250A - Current breaking device, current breaking module and control method

Info

Publication number: CN115912250A
Application number: CN202211326046.3A
Authority: CN
Inventors: 陈羽; 杨兵; 方太勋; 石巍; 吕玮; 王文杰; 许元震; 刘云飞; 赵赢峰; 孙超; 刘少飞
Original assignee: NR Electric Co Ltd; NR Engineering Co Ltd; Changzhou NR Electric Power Electronics Co Ltd
Current assignee: NR Electric Co Ltd; NR Engineering Co Ltd; Changzhou NR Electric Power Electronics Co Ltd
Priority date: 2022-10-27
Filing date: 2022-10-27
Publication date: 2023-04-04

Abstract

The application provides a current breaking device, a current breaking module and a control method, wherein the current breaking device comprises a current branch, a transfer branch, an oscillation branch and an energy consumption branch, wherein the current branch is connected with the transfer branch and the oscillation branch in parallel; the through-flow branch is formed by connecting a mechanical switch and a through-flow unit in series; the transfer branch is formed by connecting a bidirectional conduction thyristor unit and an active power electronic unit in series; the oscillation branch is formed by connecting an oscillation capacitor, a damping and vibration suppression unit and an oscillation inductor in series; the energy consumption branch is connected with the oscillation capacitor in parallel, or connected with the oscillation capacitor and the damping and vibration suppression unit in series, or connected with the oscillation capacitor and the oscillation inductor in series, or connected with the through-flow branch in parallel. According to the embodiment of the application, the mechanical switch has the advantages of reliability in breaking, short small current breaking time, high redundancy, good equipment economy and the like.

Description

Current breaking device, current breaking module and control method

Technical Field

The present application relates to the field of power electronics technologies, and in particular, to a device for breaking a current, a module for breaking a current, and a control method.

Background

In a direct current application occasion, as the fault current of the direct current power transmission and distribution system is increased quickly, reliable fault quick isolation and recovery are the key for ensuring the safe and stable operation of the direct current power transmission and distribution system. Existing dc circuit breakers include mechanical dc circuit breakers, hybrid dc circuit breakers, and all-solid-state dc circuit breakers. The mechanical direct-current circuit breaker can be divided into a passive oscillation technology and an active oscillation technology, and the mechanical direct-current circuit breaker uses a capacitor, so that the size of equipment in the mechanical direct-current circuit breaker is large, a long time is needed when a small current working condition is broken, the zero-crossing restriking risk of a mechanical switch is large, the mechanical direct-current circuit breaker is easy to oscillate with a direct-current system in the breaking process, and potential hazards are brought to normal safe operation of the system and other equipment. The hybrid direct current circuit breaker combines a mechanical switch and a power electronic technology, realizes current controllable breaking through a power electronic device, has the characteristics of no arc, quick reclosing and the like, and has good system applicability, but the breaking current technical performance and the equipment economic performance are both limited by a fully-controlled power electronic device, thereby being not beneficial to large-scale popularization and application of the hybrid direct current circuit breaker in a high-voltage direct current transmission system. Since the through-current loss of the all-solid-state dc circuit breaker is large, the all-solid-state dc circuit breaker is generally not selected for fault isolation and recovery.

The inventor finds that in an alternating current application occasion, a conventional alternating current circuit breaker can only naturally extinguish at a current zero crossing point to complete current breaking, a larger first half-wave fault current peak value has adverse effects on certain sensitive or important equipment, and the alternating current circuit breaker capable of quickly breaking current in advance is urgently needed.

Disclosure of Invention

The application provides a device for breaking current, a module for breaking current and a control method, which are used for solving the problems that a direct current breaker in the prior art has large mechanical switch reignition risk, long breaking time of small current, obvious system oscillation, high equipment cost and the like, and the problems that first half-wave high-amplitude fault current influences sensitive or important equipment when an alternating current breaker is broken.

According to an aspect of the present application, a device for breaking current is provided, where the device for breaking current includes a current path, a transfer path, an oscillation path, and an energy consumption path, where the current path is connected in parallel with the transfer path and the oscillation path; the through-flow branch is formed by connecting a mechanical switch and a through-flow unit in series; the transfer branch is formed by connecting a bidirectional conduction thyristor unit and an active power electronic unit in series;

the oscillation branch is formed by connecting an oscillation capacitor, a damping vibration suppression unit and an oscillation inductor in series; the energy consumption branch is connected with the oscillation capacitor in parallel, or connected with the oscillation capacitor and the damping and vibration suppression unit in parallel, or connected with the oscillation capacitor and the oscillation inductor in parallel, or connected with the through-flow branch in parallel.

According to some embodiments, the active power electronic unit is formed by at least one active power electronic module with bypass function connected in series, wherein the active power electronic module with bypass function comprises an electronic power switch, an active power electronic module bypass switch and a voltage source, wherein the power electronic switch comprises a first power electronic switch and a second power electronic switch, the active power electronic module bypass switch comprises a first bypass switch, the voltage source comprises a first voltage source, an anode of the first power electronic switch is connected with an anode of the first voltage source, a cathode of the first power electronic switch is connected with an anode of the second power electronic switch and then leads out an external connection, a cathode of the second power electronic switch is connected with a cathode of the first voltage source and then leads out an external connection, and the first bypass switch is connected in parallel between two external connection leads out; or

The active power electronic module with the bypass function comprises an electronic power switch, an active power electronic module bypass switch and a voltage source, wherein the power electronic switch comprises a third power electronic switch, a fourth power electronic switch, a fifth power electronic switch and a sixth power electronic switch; or

The active power electronic module with the bypass function comprises an electronic power switch, an active power electronic module bypass switch and a voltage source, wherein the power electronic switch comprises a seventh power electronic switch and an eighth power electronic switch, the active power electronic module bypass switch comprises a third bypass switch, the voltage source comprises a third voltage source and a fourth voltage source, the anode of the seventh power electronic switch is connected with the anode of the third voltage source, the cathode of the seventh power electronic switch is connected with the anode of the eighth power electronic switch and then leads out an external wire, the cathode of the eighth power electronic switch is connected with the cathode of the fourth voltage source, the cathode of the third voltage source is connected with the anode of the fourth voltage source and then leads out an external wire, and the third bypass switch is connected between the two external wires in parallel.

According to some embodiments, the operation mode of the active power electronic module with bypass function comprises an exit mode in which the active power electronic module bypass switch is closed and a throw-in mode; in the throw-in mode, the active power electronics module bypass switch is open.

According to some embodiments, the active power electronic unit is formed by at least one active power electronic module with an isolation function connected in parallel, wherein the active power electronic module with an isolation function comprises an electronic power switch, an isolation switch and a voltage source, wherein the power electronic switch comprises a ninth power electronic switch and a tenth power electronic switch, the isolation switch comprises a first isolation switch, the voltage source comprises a fifth voltage source, an anode of the ninth power electronic switch is connected with an anode of the fifth voltage source, a cathode of the ninth power electronic switch is respectively connected with an anode of the tenth power electronic switch and a first end of the first isolation switch, a second end of the first isolation switch leads out an external connection, and a cathode of the tenth power electronic switch is connected with a cathode of the fifth voltage source and then leads out an external connection; or

The active power electronic module with the isolation function comprises an electronic power switch, an isolation switch and a voltage source, wherein the power electronic switch comprises an eleventh power electronic switch, a twelfth power electronic switch, a thirteenth power electronic switch and a fourteenth power electronic switch, the isolation switch comprises a second isolation switch, the voltage source comprises a sixth voltage source, the anode of the eleventh power electronic switch is respectively connected with the anode of the thirteenth power electronic switch and the anode of the sixth voltage source, the cathode of the eleventh power electronic switch is connected with the anode of the twelfth power electronic switch and then leads out an external connection line, the cathode of the twelfth power electronic switch is respectively connected with the cathode of the fourteenth power electronic switch and the cathode of the sixth voltage source, the cathode of the thirteenth power electronic switch is respectively connected with the anode of the fourteenth power electronic switch and the first end of the second isolation switch, and the second end of the second isolation switch leads out an external connection line; or

The active power electronic module with the isolation function comprises an electronic power switch, an isolation switch and a voltage source, wherein the electronic power switch comprises a fifteenth power electronic switch and a sixteenth power electronic switch, the isolation switch comprises a third isolation switch, the voltage source comprises a seventh voltage source and an eighth voltage source, the anode of the fifteenth power electronic switch is connected with the anode of the seventh voltage source, the cathode of the fifteenth power electronic switch is connected with the anode of the sixteenth power electronic switch and then leads out an external wire, the cathode of the sixteenth power electronic switch is connected with the cathode of the eighth voltage source, the cathode of the seventh voltage source is respectively connected with the anode of the eighth voltage source and the first end of the third isolation switch, and the second end of the third isolation switch leads out an external wire.

According to some embodiments, the operation modes of the active power electronic module with isolation function include an exit mode in which the isolation switch is open and an input mode; in the throw-in mode, the disconnector is closed.

According to some embodiments, the bidirectional conducting thyristor cell comprises a bidirectional thyristor; or

The bidirectional breakover thyristor unit comprises a first unidirectional thyristor and a second unidirectional thyristor, and the first unidirectional thyristor and the second unidirectional thyristor are connected in reverse parallel.

According to some embodiments, the damping and vibration suppression unit comprises a fifth diode, a sixth diode and a first vibration suppression capacitor, wherein the anode of the fifth diode is connected with the first end of the first vibration suppression capacitor and then leads out an external wire, the cathode of the fifth diode is connected with the anode of the sixth diode and then leads out an external wire, and the cathode of the sixth diode is connected with the second end of the first vibration suppression diode; or

The damping vibration suppression unit comprises a seventh diode, an eighth diode, a ninth diode, a twelfth polar tube and a second vibration suppression capacitor, the seventh diode, the eighth diode, the ninth diode and the twelfth polar tube form a diode full bridge, the anode and the cathode of the direct current side of the diode full bridge are respectively connected with the first end and the second end of the second vibration suppression capacitor, and the alternating current side of the diode full bridge forms two leading-out connecting wires.

According to some embodiments, the through-current unit is formed by connecting at least one bidirectional through-current module in series and parallel, wherein the bidirectional through-current module is connected with a through-current unit bypass switch in parallel; and/or the mechanical switch is formed by connecting one or more mechanical switches in series and in parallel; and/or the oscillating capacitor is formed by one or more capacitors connected in series and parallel; and/or the oscillating inductor is formed by one or more inductors in series-parallel connection; and/or the energy consumption branch is formed by connecting one or more lightning arresters in series and in parallel.

According to some embodiments, the power electronic switch is formed by at least one stage of power semiconductor devices connected in series, the power semiconductor devices comprise fully-controlled power semiconductor devices or half-controlled power semiconductor devices, the fully-controlled power semiconductor devices are one or any combination of IGBTs, IEGT, IGCTs, MOSFETs and GTOs, and the half-controlled power semiconductor devices are thyristors; and/or the voltage source is a pre-charging capacitor, or an energy storage battery, or an alternating current rectification power supply.

According to an aspect of the present application, a module for breaking current is provided, the module for breaking current includes at least two devices for breaking current as described in any previous embodiment, and the devices for breaking current are connected in series.

According to an aspect of the present application, a control method of a device for breaking an electric current is provided, the control method is used for controlling the device for breaking an electric current according to any one of the previous embodiments, the control method comprises that in response to a system normal operation command, an electric current flows through a through-flow branch, a mechanical switch of the through-flow branch is in a closed state, a through-flow unit is in a through-flow unit bypass switch closed state, and an active power electronic unit in a switch-on mode of a transfer branch is in a cut-off state or a blocking state; responding to a brake-separating instruction received when a system is in fault, opening a mechanical switch of the through-flow branch, and controlling a bypass switch of a through-flow unit of the through-flow unit to be opened and a bidirectional through-flow module to be conducted; when the bypass switch of the through-flow unit is separated to an insulation separation position and the current in the bypass switch of the through-flow unit is completely transferred to the bidirectional through-flow module, triggering the bidirectional conducting thyristor unit of the transfer branch circuit to be conducted and controlling the bidirectional through-flow module of the through-flow unit to be separated; when the mechanical switch is separated to an insulation separation position, the active power electronic unit of the transfer branch circuit is controlled to output multi-pulse square wave voltage, the output square wave voltage excites the oscillation capacitor and the oscillation inductor of the oscillation branch circuit to oscillate, oscillation current which is equal to fault current amplitude current and opposite in direction is generated, and the oscillation current enables the bidirectional conduction thyristor unit of the transfer branch circuit to have zero crossing point breaking; and when the voltage of the oscillating capacitor is greater than the residual voltage of the energy consumption branch, the fault current is transferred to the energy consumption branch and is dissipated to zero, the brake is successfully opened, and the brake opening operation is finished.

According to an aspect of the present application, a control method of a device for breaking current is provided, the control method is used for controlling the device for breaking current as described in any previous embodiment, the control method comprises that in response to a system normal operation command, current flows through a through-flow branch, a mechanical switch of the through-flow branch is in a closed state, a through-flow unit is in a through-flow unit bypass switch open state and a bidirectional through-flow module conducting state, and an active power electronic unit in a switch-in mode of a transfer branch is in a cut-off state or a blocking state; triggering the bidirectional conduction thyristor unit of the transfer branch circuit to conduct in response to a brake separating instruction received when a system fails, and controlling the bidirectional through-current module of the through-current unit to break; when the current is completely transferred from the through-current branch to the transfer branch, the mechanical switch is opened without arc; when the mechanical switch is separated to an insulation separation position, the active power electronic unit of the transfer branch circuit is controlled to output multi-pulse square wave voltage, the output square wave voltage excites the oscillation capacitor and the oscillation inductor of the oscillation branch circuit to oscillate, oscillation current which is equal to fault current amplitude current and opposite in direction is generated, and the oscillation current enables the bidirectional conduction thyristor unit of the transfer branch circuit to have zero-crossing point breaking; and when the voltage of the oscillating capacitor is greater than the residual voltage of the energy consumption branch, the fault current starts to be transferred to the energy consumption branch and is dissipated to zero, the switching-off is successful, and the switching-off operation is finished.

According to the embodiment of the application, when the device for breaking the current is switched off, the internal elements of the current branch, the transfer branch and the oscillation branch are controlled to operate, the current of the current branch is transferred into the transfer branch, and then the square wave voltage is output by the active power electronic unit to oscillate to generate the oscillation current which is equal to the amplitude current of the fault current and has the opposite direction, so that the transfer branch is subjected to zero crossing and natural breaking, the problems of high reignition risk of a mechanical switch, long breaking time of a small current, obvious system oscillation, high equipment cost and the like are solved, and the device is favorable for large-scale popularization and application in an alternating current and direct current power transmission and distribution system.

According to other embodiments, the active power electronic unit of the through-current branch adopts an active oscillation boosting principle, the amplitude of reverse injection current is improved, the number of modules in the active power electronic unit is small, redundancy is configured, and the economy and reliability of equipment are obviously improved.

According to other embodiments, the oscillation capacitor of the oscillation branch circuit is a pulse capacitor, is high in voltage resistance and has a capacitance value of uF level, the breaking time of a small current is reduced, and meanwhile the volume and the cost of a capacitor are reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for the description of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description are only some embodiments of the present application.

Fig. 1 shows a block diagram of an apparatus for breaking a current according to an exemplary embodiment of the present application.

Fig. 2 is a schematic diagram illustrating a circuit structure of a device for breaking current according to an exemplary embodiment of the present application.

Fig. 3 is a schematic diagram illustrating a circuit structure of another current breaking apparatus according to an exemplary embodiment of the present application.

Fig. 4 is a schematic diagram illustrating another circuit structure of a device for breaking current according to an exemplary embodiment of the present application.

Fig. 5 is a schematic diagram illustrating a circuit structure of another current breaking apparatus according to an exemplary embodiment of the present application.

Fig. 6 is a schematic diagram illustrating another circuit structure of a device for breaking current according to an exemplary embodiment of the present application.

Fig. 7 is a schematic diagram illustrating a circuit structure of another current breaking apparatus according to an exemplary embodiment of the present application.

Fig. 8 is a schematic diagram illustrating a circuit structure of another current breaking apparatus according to an exemplary embodiment of the present application.

Fig. 9 is a schematic diagram illustrating another circuit structure of a device for breaking current according to an exemplary embodiment of the present application.

Fig. 10a shows a schematic circuit diagram of an active power electronic module with bypass function according to an exemplary embodiment of the present application.

Fig. 10b shows a schematic circuit diagram of another active power electronic module with bypass function according to an example embodiment of the present application.

Fig. 10c shows a schematic circuit configuration of another active power electronic module with bypass function according to an exemplary embodiment of the present application.

Fig. 11a shows a schematic circuit diagram of an active power electronic module with isolation function according to an exemplary embodiment of the present application.

Fig. 11b shows a schematic circuit diagram of an active power electronic module with isolation according to an example embodiment of the present application.

Fig. 11c shows a schematic circuit diagram of an active power electronic module with isolation according to an example embodiment of the present application.

Fig. 12a shows a schematic circuit diagram of a bidirectional conducting thyristor cell of a transfer branch according to an exemplary embodiment of the application.

Fig. 12b shows a schematic circuit diagram of a bidirectional conducting thyristor cell of a transfer branch according to an exemplary embodiment of the application.

Fig. 13a shows a schematic circuit topology of a current unit according to an exemplary embodiment of the present application.

Fig. 13b shows another circuit topology schematic of a current unit according to an exemplary embodiment of the present application.

Fig. 13c shows another circuit topology schematic of a current unit according to an exemplary embodiment of the present application.

Fig. 13d shows another circuit topology schematic of a current unit according to an exemplary embodiment of the present application.

Fig. 14a shows a schematic circuit diagram of a damping unit of an oscillating branch according to an exemplary embodiment of the present application.

Fig. 14b shows a schematic circuit diagram of a damping unit of an oscillating branch according to an exemplary embodiment of the present application.

Fig. 15 is a block diagram illustrating a current breaking module according to an exemplary embodiment of the present application.

Fig. 16 is a block diagram illustrating another block structure for breaking a current according to an exemplary embodiment of the present application.

Fig. 17 shows a flow chart of a control method according to an example embodiment of the present application.

Fig. 18a shows a schematic current flow diagram under a control method according to an example embodiment of the present application.

Fig. 18b shows another current flow diagram under a control method according to an example embodiment of the present application.

Fig. 18c shows another current flow diagram under a control method according to an example embodiment of the present application.

Fig. 18d shows another current flow diagram under a control method according to an example embodiment of the present application.

Fig. 18e shows another current flow diagram under a control method according to an example embodiment of the present application.

Fig. 18f shows another current flow diagram under a control method according to an example embodiment of the present application.

FIG. 19 shows a flow chart of another control method according to an example embodiment of the present application.

Fig. 20a shows a schematic current flow diagram under a control method according to an example embodiment of the present application.

Fig. 20b shows another current flow diagram under a control method according to an example embodiment of the present application.

Fig. 20c shows another current flow diagram under a control method according to an example embodiment of the present application.

Fig. 20d shows another current flow diagram under a control method according to an example embodiment of the present application.

Fig. 20e shows another current flow diagram under a control method according to an example embodiment of the present application.

Fig. 20f shows another current flow diagram under a control method according to an example embodiment of the present application.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals denote the same or similar parts in the drawings, and thus, a repetitive description thereof will be omitted.

The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the embodiments of the disclosure can be practiced without one or more of the specific details, or with other means, components, materials, devices, or operations. In such cases, well-known structures, methods, devices, implementations, materials, or operations are not shown or described in detail.

The flowcharts shown in the figures are illustrative only and do not necessarily include all of the contents and operations/steps, nor do they necessarily have to be performed in the order described. For example, some operations/steps may be decomposed, and some operations/steps may be combined or partially combined, so that the actual execution sequence may be changed according to the actual situation.

The terms "first," "second," and the like in the description and claims of the present application and in the above-described drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

Specific embodiments according to the present application will be described in detail below with reference to the accompanying drawings.

Fig. 1 shows a block diagram of an apparatus for breaking current according to an exemplary embodiment of the present application, and the apparatus for breaking current shown in fig. 1 includes a current-passing branch 1, a transfer branch 2, an oscillating branch 3, and a power-consuming branch 4.

According to an embodiment of the application, the current branch 1 is connected in parallel with the transfer branch 2 and the oscillating branch 3.

According to some embodiments, the current branch 1 is constituted by a mechanical switch in series with a current unit.

According to some embodiments, the transfer branch 2 is constituted by a bidirectional conducting thyristor cell and an active power electronic cell in series.

According to some embodiments, the oscillation branch 3 is formed by connecting an oscillation capacitor, a damping and vibration suppressing unit, and an oscillation inductor in series.

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

According to further embodiments, the dissipative branch 4 is connected in parallel with the series connection of the oscillation capacitor and the damping and damping unit.

According to further embodiments, the energy consuming branch 4 is connected in parallel with a series connection of a tank capacitor and a tank inductor.

According to further embodiments, the energy consuming branches 4 are connected in parallel with the through-flow branches.

According to some embodiments, the active power electronic unit is constituted by at least one active power electronic module with bypass function connected in series. The active power electronic module with the bypass function comprises an electronic power switch, an active power electronic module bypass switch and a voltage source.

According to further embodiments, the active power electronic unit is formed by at least one active power electronic module with an isolation function connected in parallel. The active power electronic module with the isolation function comprises an electronic power switch, an isolation switch and a voltage source.

According to the embodiment of the application, the through-current unit is formed by connecting at least one bidirectional through-current module which is connected with a through-current unit bypass switch in parallel in series and parallel; and/or the mechanical switch is formed by connecting one or more mechanical switches in series and in parallel; and/or the oscillating capacitor is formed by one or more capacitors connected in series and parallel; and/or the oscillating inductor is formed by one or more inductors in series-parallel connection; and/or the energy consumption branch is formed by connecting one or more lightning arresters in series and in parallel.

Fig. 2 is a schematic circuit diagram of an apparatus for breaking current according to an exemplary embodiment of the present application, and the apparatus for breaking current shown in fig. 2 includes a current-passing branch 1, a transfer branch 2, an oscillating branch 3, and a power-consuming branch 4. The current branch circuit 1 is connected with the transfer branch circuit 2 and the oscillation branch circuit 3 in parallel, the current branch circuit 1 is formed by connecting a mechanical switch 11 and a current unit 12 in series, the transfer branch circuit 2 is formed by connecting a bidirectional conduction thyristor unit 21 and an active power electronic unit 22 in series, the oscillation branch circuit 3 is formed by connecting an oscillation capacitor 31, a damping and vibration suppression unit 32 and an oscillation inductor 33 in series, the energy consumption branch circuit 4 is connected with the oscillation capacitor 31 in parallel, and the active power electronic unit 22 is formed by connecting at least one active power electronic module with a bypass function in series.

Fig. 3 is a schematic circuit diagram of another current breaking apparatus according to an exemplary embodiment of the present application, and the current breaking apparatus shown in fig. 3 includes a current flowing branch 1, a transferring branch 2, an oscillating branch 3, and a power consuming branch 4. The current branch circuit 1 is connected with the transfer branch circuit 2 and the oscillation branch circuit 3 in parallel, the current branch circuit 1 is formed by connecting a mechanical switch 11 and a current unit 12 in series, the transfer branch circuit 2 is formed by connecting a bidirectional conduction thyristor unit 21 and an active power electronic unit 22 in series, the oscillation branch circuit 3 is formed by connecting an oscillation capacitor 31, a damping and vibration suppression unit 32 and an oscillation inductor 33 in series, the energy consumption branch circuit 4 is connected with the oscillation capacitor 31 and the damping and vibration suppression unit 32 which are connected in series in parallel, and the active power electronic unit 22 is formed by connecting at least one active power electronic module with a bypass function in series.

Fig. 4 is a schematic diagram showing a circuit configuration of another current breaking apparatus according to an exemplary embodiment of the present application, and the current breaking apparatus shown in fig. 4 includes a current-carrying branch 1, a transfer branch 2, an oscillation branch 3, and a power consumption branch 4, where 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 formed by connecting a mechanical switch 11 in series with a current-carrying unit 12, the transfer branch 2 is formed by connecting a bidirectional conducting thyristor unit 21 in series with an active power electronic unit 22, the oscillation branch 3 is formed by connecting an oscillation capacitor 31, a damping unit 32, and an oscillation inductor 33 in series, the power consumption branch 4 is connected in parallel with the oscillation capacitor 31 and the oscillation inductor 33 connected in series, and the active power electronic unit 22 is formed by connecting at least one active power electronic module having a bypass function in series.

Fig. 5 is a schematic circuit diagram of another current dividing apparatus according to an exemplary embodiment of the present application, and the current dividing apparatus shown in fig. 5 includes a current branch 1, a transfer branch 2, an oscillation branch 3, and a power consumption branch 4. The current-passing branch 1, the transfer branch 2 and the oscillation branch 3 are connected in parallel, the current-passing branch 1 is formed by connecting a mechanical switch 11 and a current-passing unit 12 in series, the transfer branch 2 is formed by connecting a bidirectional conduction thyristor unit 21 and an active power electronic unit 22 in series, the oscillation branch 3 is formed by connecting an oscillation capacitor 31, a damping and vibration suppression unit 32 and an oscillation inductor 33 in series, the energy consumption branch 4 is connected with the current-passing branch 1 in parallel, and the active power electronic unit 22 is formed by connecting at least one active power electronic module with a bypass function in series.

Fig. 6 is a schematic circuit diagram of another current dividing apparatus according to an exemplary embodiment of the present application, and the current dividing apparatus shown in fig. 6 includes a current branch 1, a transfer branch 2, an oscillation branch 3, and a power consumption branch 4. The current-passing branch 1, the transfer branch 2 and the oscillation branch 3 are connected in parallel, the current-passing branch 1 is formed by connecting a mechanical switch 11 and a current-passing unit 12 in series, the transfer branch 2 is formed by connecting a bidirectional conduction thyristor unit 21 and an active power electronic unit 22 in series, the oscillation branch 3 is formed by connecting an oscillation capacitor 31, a damping and vibration suppression unit 32 and an oscillation inductor 33 in series, the energy consumption branch 4 is connected with the oscillation capacitor 31 in parallel, and the active power electronic unit 22 is formed by connecting at least one active power electronic module with an isolation function in parallel.

Fig. 7 is a schematic circuit diagram of another current dividing apparatus according to an exemplary embodiment of the present application, and the current dividing apparatus shown in fig. 7 includes a current branch 1, a transfer branch 2, an oscillation branch 3, and a power consumption branch 4. The current-passing branch 1, the transfer branch 2 and the oscillation branch 3 are connected in parallel, the current-passing branch 1 is formed by connecting a mechanical switch 11 and a current-passing unit 12 in series, the transfer branch 2 is formed by connecting a bidirectional conduction thyristor unit 21 and an active power electronic unit 22 in series, the oscillation branch 3 is formed by connecting an oscillation capacitor 31, a damping and vibration suppression unit 32 and an oscillation inductor 33 in series, the energy consumption branch 4 is connected with the oscillation capacitor 31 and the damping and vibration suppression unit 32 which are connected in series in parallel, and the active power electronic unit 22 is formed by connecting at least one active power electronic module with an isolation function in parallel.

Fig. 8 is a schematic circuit diagram of another current breaking apparatus according to an exemplary embodiment of the present application, and the current breaking apparatus shown in fig. 8 includes a current flowing branch 1, a transferring branch 2, an oscillating branch 3, and a power consuming branch 4. The current-passing branch 1, the transfer branch 2 and the oscillation branch 3 are connected in parallel, the current-passing branch 1 is formed by connecting a mechanical switch 11 and a current-passing unit 12 in series, the transfer branch 2 is formed by connecting a bidirectional conduction thyristor unit 21 and an active power electronic unit 22 in series, the oscillation branch 3 is formed by connecting an oscillation capacitor 31, a damping and vibration suppression unit 32 and an oscillation inductor 33 in series, the energy consumption branch 4 is connected with the oscillation capacitor 31 and the oscillation inductor 33 which are connected in series in parallel, and the active power electronic unit 22 is formed by connecting at least one active power electronic module with an isolation function in parallel.

Fig. 9 is a schematic diagram illustrating a circuit configuration of another current dividing apparatus according to an exemplary embodiment of the present application, and the current dividing apparatus shown in fig. 9 includes a current passing branch 1, a transfer branch 2, an oscillating branch 3, and a power consuming branch 4. The current-passing branch 1, the transfer branch 2 and the oscillation branch 3 are connected in parallel, the current-passing branch 1 is formed by connecting a mechanical switch 11 and a current-passing unit 12 in series, the transfer branch 2 is formed by connecting a bidirectional conduction thyristor unit 21 and an active power electronic unit 22 in series, the oscillation branch 3 is formed by connecting an oscillation capacitor 31, a damping and vibration suppression unit 32 and an oscillation inductor 33 in series, the energy consumption branch 4 is connected with the current-passing branch 1 in parallel, and the active power electronic unit 22 is formed by connecting at least one active power electronic module with an isolation function in parallel.

Fig. 10a shows a schematic circuit diagram of an active power electronic module with bypass function according to an exemplary embodiment of the present application, the active power electronic module shown in fig. 10a comprising a power electronic switch, an active power electronic module bypass switch and a voltage source. Wherein the power electronic switch comprises a first power electronic switch and a second power electronic switch, the active power electronic module bypass switch comprises a first bypass switch, and the voltage source comprises a first voltage source.

As shown in fig. 10a, the positive electrode of the first power electronic switch is connected to the positive electrode of the first voltage source, the negative electrode of the first power electronic switch is connected to the positive electrode of the second power electronic switch and then leads out an external connection line, the negative electrode of the second power electronic switch is connected to the negative electrode of the first voltage source and then leads out an external connection line, and the first bypass switch is connected in parallel between the two external connection lines.

Fig. 10b shows a schematic circuit diagram of another active power electronic module with bypass function according to an exemplary embodiment of the present application, the active power electronic module as shown in fig. 10b comprising a power electronic switch, an active power electronic module bypass switch and a voltage source. The power electronic switch comprises 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 comprises a second bypass switch, and the voltage source comprises a second voltage source.

As shown in fig. 10b, the positive electrode of the third power electronic switch is connected to the positive electrode of the fifth power electronic switch and the positive electrode of the second voltage source, the negative electrode of the third power electronic switch is connected to the positive electrode of the fourth power electronic switch and then leads out an external connection, the negative electrode of the fourth power electronic switch is connected to the negative electrode of the sixth power electronic switch and the negative electrode of the second voltage source, the negative electrode of the fifth power electronic switch is connected to the positive electrode of the sixth power electronic switch and then leads out an external connection, and the second bypass switch is connected in parallel between the two external connection.

Fig. 10c shows a schematic circuit diagram of another active power electronic module with bypass function according to an example embodiment of the present application, the active power electronic module shown in fig. 10c comprising a power electronic switch, an active power electronic module bypass switch and a voltage source. Wherein the power electronic switches comprise a seventh power electronic switch and an eighth power electronic switch, the active power electronic module bypass switches comprise a third bypass switch, and the voltage sources comprise a third voltage source and a fourth voltage source.

As shown in fig. 10c, the positive electrode of the seventh power electronic switch is connected to the positive electrode of the third voltage source, the negative electrode of the seventh power electronic switch is connected to the positive electrode of the eighth power electronic switch to lead out an external connection, the negative electrode of the eighth power electronic switch is connected to the negative electrode of the fourth voltage source, the negative electrode of the third voltage source is connected to the positive electrode of the fourth voltage source to lead out an external connection, and the third bypass switch is connected in parallel between the two external connection.

The operating modes of the active power electronic module with bypass function in fig. 10a-10c include an exit mode and an engage mode. Wherein, in the exit mode, the active power electronic module bypass switch is closed; in the throw-in mode, the active power electronics module bypass switch is open. In order to improve the reliability of the device for breaking current, the active power electronic unit of the transfer branch is provided with a redundant module, i.e. with a plurality of active power electronic modules. When the active power electronic module fails, the failed active power electronic module is switched from the input mode to the exit mode, and any other active power electronic module is selected to be switched to the input mode.

Fig. 11a shows a schematic circuit diagram of an active power electronic module with an isolation function according to an exemplary embodiment of the present application, where the active power electronic module shown in fig. 11a includes a power electronic switch, an isolation switch, and a voltage source. Wherein the power electronic switches comprise a ninth power electronic switch and a tenth power electronic switch, the disconnectors comprise first disconnectors, and the voltage source comprises a fifth voltage source.

As shown in fig. 11a, the positive electrode of the ninth power electronic switch is connected to the positive electrode of the fifth voltage source, the negative electrode of the ninth power electronic switch is connected to the positive electrode of the tenth power electronic switch and the first end of the first isolating switch, respectively, the second end of the first isolating switch is connected to the external connection line, and the negative electrode of the tenth power electronic switch is connected to the negative electrode of the fifth voltage source and then connected to the external connection line.

Fig. 11b shows a schematic circuit diagram of an active power electronic module with an isolation function according to an exemplary embodiment of the present application, where the active power electronic module shown in fig. 11b includes a power electronic switch, an isolation switch and a voltage source. Wherein the power electronic switches comprise an eleventh power electronic switch, a twelfth power electronic switch, a thirteenth power electronic switch, and a fourteenth power electronic switch, the isolation switches comprise second isolation switches, and the voltage source comprises a sixth voltage source.

As shown in fig. 11b, the positive electrode of the eleventh power electronic switch is connected to the positive electrode of the thirteenth power electronic switch and the positive electrode of the sixth voltage source, the negative electrode of the eleventh power electronic switch is connected to the positive electrode of the twelfth power electronic switch, and then an external connection is led out, the negative electrode of the twelfth power electronic switch is connected to the negative electrode of the fourteenth power electronic switch and the negative electrode of the sixth voltage source, the negative electrode of the thirteenth power electronic switch is connected to the positive electrode of the fourteenth power electronic switch and the first end of the second isolating switch, and the second end of the second isolating switch is led out of the external connection.

Fig. 11c shows a schematic circuit diagram of an active power electronic module with isolation function according to an exemplary embodiment of the present application, where the active power electronic module shown in fig. 11c includes a power electronic switch, an isolation switch and a voltage source. The power electronic switch comprises a fifteenth power electronic switch and a sixteenth power electronic switch, the isolating switch comprises a third isolating switch, and the voltage source comprises a seventh voltage source and an eighth voltage source.

As shown in fig. 11c, the positive electrode of the fifteenth power electronic switch is connected to the positive electrode of the seventh voltage source, the negative electrode of the fifteenth power electronic switch is connected to the positive electrode of the sixteenth power electronic switch and then an external connection line is led out, the negative electrode of the sixteenth power electronic switch is connected to the negative electrode of the eighth voltage source, the negative electrode of the seventh voltage source is connected to the positive electrode of the eighth voltage source and the first end of the third isolating switch, respectively, and the second end of the third isolating switch is led out the external connection line.

The operation modes of the active power electronic module with isolation function in fig. 11a-11c include an exit mode and an entry mode. In the exit mode, the isolating switch is opened; in the throw-in mode, the disconnector is closed.

In order to increase the reliability of the device for segmenting the current, the active power electronic unit of the transfer branch is provided with a redundant module, namely a plurality of active power electronic modules. When the active power electronic module has a fault, the fault module is switched from the input mode to the exit mode, and any other active power electronic module is selected to be switched to the input mode.

According to an embodiment of the 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 formed by at least one stage of power semiconductor devices, the power semiconductor devices include fully-controlled power semiconductor devices or half-controlled power semiconductor devices, the fully-controlled power semiconductor devices are one or any combination of IGBTs, IEGTs, IGCTs, MOSFETs, GTOs, and the half-controlled power semiconductor devices are thyristors.

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 or energy storage batteries or ac rectified power sources, and in order to protect the voltage sources and prevent overvoltage damage during current turn-off, overvoltage measures such as lightning arresters or crowbar (chopper) circuits can be connected in parallel to the two ends of the voltage sources.

Fig. 12a shows a schematic circuit configuration of a bidirectional thyristor cell of a transfer branch according to an exemplary embodiment of the application, the bidirectional thyristor cell as shown in fig. 12a comprising a bidirectional thyristor.

Fig. 12b shows a schematic circuit structure diagram of a bidirectional conducting thyristor unit of a transfer branch according to an exemplary embodiment of the present application, where the bidirectional conducting thyristor unit shown in fig. 12b includes a first unidirectional thyristor and a second unidirectional thyristor, and the first unidirectional thyristor and the second unidirectional thyristor are connected in anti-parallel.

According to some embodiments, the current unit is composed of at least one bidirectional current module connected in series and in parallel with a bypass switch, and fig. 13a to 13d respectively show typical circuit topology schematic diagrams of four current units.

Fig. 14a is a schematic circuit diagram illustrating a damping and vibration suppressing unit of an oscillation branch according to an exemplary embodiment of the present application, where the damping and vibration suppressing unit shown in fig. 14a includes a fifth diode, a sixth diode and a first vibration suppressing capacitor, an anode of the fifth diode is connected to a first end of the first vibration suppressing capacitor and then leads out an external connection, a cathode of the fifth diode is connected to an anode of the sixth diode and then leads out an external connection, and a cathode of the sixth diode is connected to a second end of the first vibration suppressing diode.

Fig. 14b is a schematic diagram of a circuit structure of a damping and vibration suppressing unit of an oscillation branch according to an exemplary embodiment of the present application, where the damping and vibration suppressing unit shown in fig. 14b includes a seventh diode, an eighth diode, a ninth diode, a twelfth diode and a second vibration suppressing capacitor, the seventh diode, the eighth diode, the ninth diode and the twelfth diode form a diode full bridge, a positive pole and a negative pole of the diode full bridge on a dc side are respectively connected with a first end and a second end of the second vibration suppressing capacitor, and an ac side of the diode full bridge forms two lead-out connection lines.

In order to protect the damping and damping unit against overvoltage damage during current shut-down, an overvoltage measure, such as a lightning arrester or crowbar (chopper) circuit, may be connected in parallel across its damping capacitor according to some embodiments.

According to some embodiments, the mechanical switch is formed by one or more mechanical switches connected in series and parallel, typically a fast switch of the fast type, which may be mechanical switches using electromagnetic repulsion or permanent magnetic or explosion principles. When multiple fast switches are connected in series, an RC loop is usually connected in parallel across each fast switch to improve the inter-break voltage-sharing performance.

According to some embodiments, the oscillating capacitor of the oscillating branch is formed by one or more capacitors connected in series and parallel, and is usually several uf or more than ten uf, high in withstand voltage and small in volume.

According to some embodiments, the oscillating inductance of the oscillating branch is formed by one or more inductances connected in series and in parallel;

according to some embodiments, the energy consuming branch is formed by one or more arresters connected in series and in parallel.

Fig. 15 is a block diagram illustrating a structure of a current-dividing module according to an exemplary embodiment of the present application, where the current-dividing module shown in fig. 15 is flexibly extended by connecting a plurality of current-dividing devices in series to meet application requirements of medium and high voltage systems.

According to other embodiments of the present application, the current dividing module may further connect internal components of the current dividing apparatus in series, for example, as shown in fig. 16, the modular units formed by the transfer branch, the oscillation branch and the energy consumption branch are connected in series to achieve flexible expansion, so as to meet application requirements of the medium and high voltage system.

Fig. 17 shows a flow chart of a control method according to an exemplary embodiment of the present application, and fig. 18a to 18f are schematic current flow diagrams under the control method according to the exemplary embodiment of the present application.

The control method shown in fig. 17 will be described in detail below with reference to fig. 18a to 18 f.

In step S1701, the current breaking apparatus receives a command.

When the system is not in fault, according to the embodiment of the present application, in response to a normal operation command of the power system, step S1703 is executed, and the device for breaking current is in the initial state engaged, that is, the current flows through the current branch, the mechanical switch of the current branch is in the closed state, the current unit is in the current unit bypass switch closed state, the current flow direction is as shown in fig. 18a, and the active power electronic unit in the switching mode of the branch is in the cut-off state or the blocking state.

According to other embodiments of the present application, the current dividing apparatus receives a switching-off command when the system fails, and in response to the switching-off command received when the power system fails, performs step S1705, and in step S1705, opens the mechanical switch of the current branch, and controls the bypass switch of the current unit to be opened and the bidirectional current module to be turned on, and the current flows as shown in fig. 18 b. The current unit bypass switch is preferably a high arc voltage bypass switch under this control method, according to some embodiments, which forces the current to shift to the bidirectional current mode.

In step S1707, when the current unit bypass switch of the current unit is disconnected to the insulation disconnection position and the current in the current unit bypass switch is completely transferred to the bidirectional current module, the bidirectional conducting thyristor unit of the transfer branch is triggered to conduct and the bidirectional current module of the current unit is controlled to disconnect, and the current flows as shown in fig. 18 c.

In step S1709, when the mechanical switch is disconnected to the insulation position, the active power electronic unit of the transfer branch is controlled to output a multi-pulse square wave voltage, and the output square wave voltage excites the oscillation capacitor and the oscillation inductor of the oscillation branch to oscillate, so as to generate an oscillation current with the same amplitude current as the fault current and the opposite direction, wherein the current flows in the alternating direction as shown in fig. 18d and 18e, and the oscillation current causes the bidirectional conduction thyristor unit of the transfer branch to break at the zero-crossing point.

In step S1711, when the transfer branch current crosses zero, the fault current starts to charge the oscillation capacitor of the oscillation branch, and when the oscillation capacitor voltage is greater than the residual voltage of the energy consuming branch, for example, the arrester residual voltage of the energy consuming branch, the fault current starts to transfer to the energy consuming branch and dissipate to zero, and the current flows as shown in fig. 18f, the opening is successful and the opening operation is ended.

Fig. 19 is a flowchart illustrating another control method according to an exemplary embodiment of the present application, and fig. 20a to 20f are schematic diagrams illustrating a current flow in the control method according to the exemplary embodiment of the present application.

In step S1901, the current breaking apparatus receives a command.

When the system is not in fault, according to the embodiment of the present application, in response to a normal operation command of the power system, step S1903 is executed, the device for breaking current is in the initial state engaged, that is, the current flows through the current branch, the mechanical switch of the current branch is in the closed state, the current unit is in the state that the bypass switch of the current unit is opened and the bidirectional current module is in the conducting state, the current flow direction is as shown in fig. 20a, and the active power electronic unit in the switching mode of the branch is in the cut-off state or the locked state;

when the system fails, the current breaking means receives the opening command, and according to other embodiments of the present application, the current breaking means performs step S1905 in response to the opening command received when the power system fails,

in step S1905, the bidirectional conducting thyristor unit of the transfer branch is triggered to conduct, and the bidirectional current block of the current unit is controlled to be disconnected, and the current flows as shown in fig. 20 b.

At step S1907, after the current is completely diverted from the circulating branch to the diverting branch, no arc opens the mechanical switch and the current flows as shown in fig. 20 c.

In step S1909, when the mechanical switch is disconnected to the insulation position, the active power electronic unit of the transfer branch is controlled to output a multi-pulse square wave voltage, and the output square wave voltage excites the oscillation capacitor and the oscillation inductor of the oscillation branch to oscillate, so as to generate an oscillation current with the same amplitude current and the opposite direction as the fault current, wherein the current flows in the alternating direction as shown in fig. 20d and 20e, and the oscillation current causes the bidirectional conduction thyristor unit of the transfer branch to break through a zero crossing point;

in step S1911, when the transfer branch current crosses zero, the fault current starts to charge the oscillation capacitor of the oscillation branch, and when the oscillation capacitor voltage is greater than the residual voltage of the energy consuming branch, for example, the arrester residual voltage of the energy consuming branch, the fault current starts to transfer to the energy consuming branch and dissipate to zero, the current flows to the branch as shown in fig. 20f, the opening is successful, and the opening operation is ended.

According to the embodiment of the application, the frequency of the square wave voltage output by the active power electronic unit is close to the resonant frequency of the oscillating capacitor and the oscillating inductor, and the current with the continuously increased current amplitude can be generated through excitation of the square wave voltage.

The foregoing detailed description of the embodiments of the present application has been presented to illustrate the principles and implementations of the present application, and the description of the embodiments is only intended to facilitate the understanding of the methods and their core concepts of the present application. Meanwhile, a person skilled in the art should, according to the idea of the present application, change or modify the embodiments and applications of the present application based on the scope of the present application. In view of the above, the description should not be taken as limiting the application.

Claims

1. A device for breaking current is characterized by comprising a through-current branch, a transfer branch, an oscillation branch and an energy consumption branch,

the through-flow branch circuit, the transfer branch circuit and the oscillation branch circuit are connected in parallel;

the through-flow branch is formed by connecting a mechanical switch and a through-flow unit in series;

the transfer branch is formed by connecting a bidirectional conduction thyristor unit and an active power electronic unit in series;

the oscillation branch is formed by connecting an oscillation capacitor, a damping and vibration suppression unit and an oscillation inductor in series;

the energy consumption branch is connected with the oscillation capacitor in parallel, or connected with the oscillation capacitor and the damping and vibration suppression unit in parallel, or connected with the oscillation capacitor and the oscillation inductor in parallel, or connected with the through-flow branch in parallel.

2. Current dividing device according to claim 1, characterized in that the active power electronic unit is formed by a series connection of at least one active power electronic module with bypass function, wherein,

the active power electronic module with the bypass function comprises an electronic power switch, an active power electronic module bypass switch and a voltage source, wherein the power electronic switch comprises a first power electronic switch and a second power electronic switch, the active power electronic module bypass switch comprises a first bypass switch, the voltage source comprises a first voltage source, the anode of the first power electronic switch is connected with the anode of the first voltage source, the cathode of the first power electronic switch is connected with the anode of the second power electronic switch and then leads out an external wire, the cathode of the second power electronic switch is connected with the cathode of the first voltage source and then leads out an external wire, and the first bypass switch is connected between the two external wires in parallel; or

The active power electronic module with the bypass function comprises an electronic power switch, an active power electronic module bypass switch and a voltage source, wherein the power electronic switch comprises a seventh power electronic switch and an eighth power electronic switch, the active power electronic module bypass switch comprises a third bypass switch, the voltage source comprises a third voltage source and a fourth voltage source, the anode of the seventh power electronic switch is connected with the anode of the third voltage source, the cathode of the seventh power electronic switch is connected with the anode of the eighth power electronic switch and then leads out an external wire, the cathode of the eighth power electronic switch is connected with the cathode of the fourth voltage source, the cathode of the third voltage source is connected with the anode of the fourth voltage source and then leads out an external wire, and the third bypass switch is connected between the two outgoing external wires in parallel.

3. Device for breaking an electric current according to claim 2, characterized in that the operating modes of the active power electronic module with bypass function comprise an exit mode and an input mode, wherein,

in the exit mode, the active power electronic mode bypass switch is closed;

in the throw-in mode, the active power electronics module bypass switch is open.

4. Current dividing device according to claim 1, characterized in that the active power electronic unit is formed by at least one active power electronic module with an isolating function connected in parallel, wherein,

the active power electronic module with the isolation function comprises an electronic power switch, an isolation switch and a voltage source, wherein the power electronic switch comprises a ninth power electronic switch and a tenth power electronic switch, the isolation switch comprises a first isolation switch, the voltage source comprises a fifth voltage source, the anode of the ninth power electronic switch is connected with the anode of the fifth voltage source, the cathode of the ninth power electronic switch is respectively connected with the anode of the tenth power electronic switch and the first end of the first isolation switch, the second end of the first isolation switch leads out an external connection wire, and the cathode of the tenth power electronic switch is connected with the cathode of the fifth voltage source and then leads out an external connection wire; or

5. Device for breaking an electric current according to claim 4, characterized in that the operating modes of the active power electronic module with isolation function comprise an exit mode and an input mode, wherein,

in the exit mode, the isolation switch is open;

in the throw-in mode, the disconnector is closed.

6. A device for breaking an electric current according to claim 1,

the bidirectional conduction thyristor unit comprises a bidirectional thyristor; or

7. A device for breaking an electric current according to claim 1,

the damping vibration suppression unit comprises a fifth diode, a sixth diode and a first vibration suppression capacitor, wherein the anode of the fifth diode is connected with the first end of the first vibration suppression capacitor and then leads out an external wire, the cathode of the fifth diode is connected with the anode of the sixth diode and then leads out an external wire, and the cathode of the sixth diode is connected with the second end of the first vibration suppression diode; or

8. A device for breaking an electric current according to claim 1,

the through-current unit is formed by connecting at least one bidirectional through-current module in series and parallel, wherein the bidirectional through-current module is connected with a through-current unit bypass switch in parallel; and/or

The mechanical switch is formed by connecting one or more mechanical switches in series and in parallel; and/or

The oscillation capacitor is formed by one or more capacitors connected in series and parallel; and/or

The oscillating inductor is formed by connecting one or more inductors in series and parallel; and/or

The energy consumption branch is formed by connecting one or more lightning arresters in series and in parallel.

9. Current dividing device according to claims 2 to 5,

the power electronic switch is formed by connecting at least one stage of power semiconductor devices in series, the power semiconductor devices comprise full-control power semiconductor devices or half-control power semiconductor devices, the full-control power semiconductor devices are one or any combination of IGBTs, IEGT, IGCTs, MOSFETs and GTOs, and the half-control power semiconductor devices are thyristors; and/or

The voltage source is a pre-charging capacitor, or an energy storage battery, or an alternating current rectification power supply.

10. A current-breaking module, characterized in that it comprises at least two current-breaking means according to any of claims 1-9, connected in series.

11. A control method for controlling a device for breaking current according to any one of claims 1 to 9, the control method comprising:

in response to a normal working instruction of the system, current flows through a through-flow branch, a mechanical switch of the through-flow branch is in a closed state, a through-flow unit is in a through-flow unit bypass switch closed state, and an active power electronic unit in a switching mode of a transfer branch is in a cut-off state or a locked state;

in response to a brake-off command received when the system fails,

opening a mechanical switch of the through-flow branch, and controlling a through-flow unit bypass switch of the through-flow unit to be opened and a bidirectional through-flow module to be conducted;

when the bypass switch of the through-flow unit is separated to an insulation separation position and the current in the bypass switch of the through-flow unit is completely transferred to the bidirectional through-flow module, triggering the bidirectional conducting thyristor unit of the transfer branch circuit to be conducted and controlling the bidirectional through-flow module of the through-flow unit to be separated;

when the mechanical switch is separated to an insulation separation position, the active power electronic unit of the transfer branch circuit is controlled to output multi-pulse square wave voltage, the output square wave voltage excites the oscillation capacitor and the oscillation inductor of the oscillation branch circuit to oscillate, oscillation current which is equal to fault current amplitude current and opposite in direction is generated, and the oscillation current enables the bidirectional conduction thyristor unit of the transfer branch circuit to have zero crossing point breaking;

and when the voltage of the oscillating capacitor is greater than the residual voltage of the energy consumption branch, the fault current is transferred to the energy consumption branch and is dissipated to zero, the switching-off is successful, and the switching-off operation is finished.

12. A control method for a device for breaking a current according to any one of claims 1 to 9, the control method comprising:

in response to a normal working instruction of the system, current flows through a through-flow branch, a mechanical switch of the through-flow branch is in a closed state, a through-flow unit is in a state that a bypass switch of the through-flow unit is opened and a bidirectional through-flow module is in a conducting state, and an active power electronic unit in a switching mode of a transfer branch is in a cut-off state or a locked state;

triggering the bidirectional conduction thyristor unit of the transfer branch circuit to conduct in response to a brake separating instruction received when a system fails, and controlling the bidirectional through-current module of the through-current unit to break;

when the current is completely transferred from the through-current branch to the transfer branch, the mechanical switch is opened without arc;

when the mechanical switch is separated to an insulation separation position, the active power electronic unit of the transfer branch circuit is controlled to output multi-pulse square wave voltage, the output square wave voltage excites the oscillation capacitor and the oscillation inductor of the oscillation branch circuit to oscillate, oscillation current which is equal to fault current amplitude current and opposite in direction is generated, and the oscillation current enables the bidirectional conduction thyristor unit of the transfer branch circuit to have zero-crossing point breaking;

and when the voltage of the oscillating capacitor is greater than the residual voltage of the energy consumption branch, the fault current starts to be transferred to the energy consumption branch and is dissipated to zero, the brake is successfully opened, and the brake opening operation is finished.