Passive current interruption device, current interruption module, and current interruption control method

Abstract

The application discloses a passive current breaking device, a current breaking module and a current breaking control method, and belongs to the field of circuit breakers. The device comprises a through-flow branch, an oscillation branch and an energy consumption branch. The through-flow branch is in series connection of a mechanical switch and a damping excitation unit. The oscillation branch is in series connection of an oscillation capacitor and an oscillation inductor and is in parallel connection at both ends of the through-flow branch. The energy consumption branch is an arrester and is in parallel connection at both ends of the oscillation capacitor, or at both ends of the oscillation branch, or at both ends of the mechanical switch. The module is in series connection of a plurality of passive current breaking devices. The control method is as follows: when the device is tripped, the internal elements of the through-flow branch are controlled to operate, the damping excitation unit utilizes line current and passive module output voltage, and oscillation generates an oscillation current which is equal in amplitude and opposite in direction to a fault current, so that the mechanical switch is zero-crossed and naturally broken. The application overcomes the problems of pre-charging of the capacitor, long small-current breaking time, significant system oscillation and high equipment cost.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of circuit breakers, and particularly relates to a passive current breaking device and a control method thereof. BACKGROUND

[0002] In a DC application scenario, reliable fault rapid isolation and recovery are the key to ensure the safe and stable operation of the DC power transmission and distribution system. Existing DC circuit breakers include mechanical DC circuit breakers and hybrid DC circuit breakers. The mechanical DC circuit breaker has the disadvantages of capacitor pre-charge, long time for breaking small current, easy oscillation with the DC system during the breaking process, and hidden dangers to the normal and safe operation of the system and other devices. The hybrid DC circuit breaker combines mechanical switches and power electronic technology, realizes controllable breaking of current through power electronic devices, has the characteristics of no arc and fast reclosing, and has good system applicability. However, the breaking current technical performance and equipment economic performance are limited by the full-controlled power electronic devices, which is not conducive to the large-scale promotion and application of the hybrid DC circuit breaker in the high-voltage DC power transmission system. SUMMARY

[0003] In view of the above defects or improvement needs of the prior art, the present application provides a passive current breaking device and a control method thereof.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows.

[0005] A passive current breaking device, comprising:

[0006] A through-flow branch, which is composed of a mechanical switch and a damping excitation unit in series;

[0007] An oscillation branch, which is composed of an oscillation capacitor and an oscillation inductor in series, and is connected in parallel with the through-flow branch;

[0008] An energy consumption branch, which is connected in parallel with the oscillation branch, or connected in parallel with the oscillation capacitor, or connected in parallel with the mechanical switch.

[0009] In some embodiments, the damping excitation unit is composed of at least one bidirectional through-flow passive module with bypass function in series.

[0010] In some embodiments, the bidirectional current-passing passive module comprises a first power electronic switch, a second power electronic switch, a first bypass switch and a first resistor, the negative pole of the first power electronic switch is connected with the negative pole of the second power electronic switch, the positive pole of the first power electronic switch leads out a first external wire, the positive pole of the second power electronic switch leads out a second external wire, the first bypass switch and the first resistor are connected in parallel between the first external wire and the second external wire respectively; or

[0011] The bidirectional current-passing passive module comprises a third power electronic switch, a fourth power electronic switch, a second bypass switch and a second resistor, the negative pole of the third power electronic switch is connected with the positive pole of the fourth power electronic switch and leads out a third external wire, the positive pole of the third power electronic switch is connected with the negative pole of the fourth power electronic switch and leads out a fourth external wire, the second bypass switch and the second resistor are connected in parallel between the third external wire and the fourth external wire respectively; or

[0012] The bidirectional current-passing passive module comprises a fifth power electronic switch, a sixth power electronic switch, a seventh power electronic switch, an eighth power electronic switch, a third bypass switch and a third resistor, the positive pole of the fifth power electronic switch is connected with the positive pole of the seventh power electronic switch and the third resistor respectively, the negative pole of the fifth power electronic switch is connected with the positive pole of the sixth power electronic switch and leads out a fifth external wire, the negative pole of the sixth power electronic switch is connected with the negative pole of the eighth power electronic switch and the other end of the third resistor respectively, the negative pole of the seventh power electronic switch is connected with the positive pole of the eighth power electronic switch and leads out a sixth external wire, the third bypass switch is connected in parallel between the fifth external wire and the sixth external wire; or

[0013] The bidirectional current-passing passive module comprises a ninth power electronic switch, a first diode, a second diode, a third diode, a fourth diode, a fourth bypass switch and a fourth resistor, the first diode, the second diode, the third diode and the fourth diode constitute a diode full-bridge, the positive pole and the negative pole of the ninth power electronic switch are connected with the positive pole and the negative pole of the direct current side of the diode full-bridge respectively, the fourth resistor is connected in parallel between the two ends of the ninth power electronic switch, the alternating current side of the diode full-bridge leads out a seventh external wire and an eighth external wire, the fourth bypass switch is connected in parallel between the seventh external wire and the eighth external wire.

[0014] In some embodiments, 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 are all composed of at least one series of fully controllable power semiconductor devices, which are one or any combination of IGBT, IEGT, IGCT, MOSFET, GTO.

[0015] In some embodiments, the first diode, the second diode, the third diode, the fourth diode are all composed of at least one series of non-controllable power semiconductor devices, which are one or any combination of rectifier diode, fast recovery diode.

[0016] In some embodiments, the first resistor, the second resistor, the third resistor, the fourth resistor are all composed of at least one series and parallel of resistors, which are one or any combination of non-linear resistor, linear resistor.

[0017] In some embodiments, the mechanical switch is composed of one or more mechanical switches in series and parallel; and / or

[0018] The oscillation capacitor is composed of one or more capacitors in series and parallel; and / or

[0019] The oscillation inductor is composed of one or more inductors in series and parallel; and / or

[0020] The energy dissipation branch is composed of one or more arresters in series and parallel.

[0021] In some embodiments, the oscillation capacitor is a pulse capacitor.

[0022] In some embodiments, the working modes of the damping excitation unit include bypass mode, through-flow mode and oscillation mode.

[0023] In the bypass mode, the bypass switch and the power electronic switch of the bidirectional through-flow passive module of the damping excitation unit are closed.

[0024] In the through-flow mode, the bypass switch of the bidirectional through-flow passive module of the damping excitation unit is opened, and the power electronic switch is turned on.

[0025] In the oscillation mode, the bypass switch of the bidirectional through-flow passive module of the damping excitation unit is opened, and the output characteristics of the bidirectional through-flow passive module are controlled through the power electronic switch, and the bidirectional through-flow passive module switches between low resistance and high resistance states.

[0026] When the bidirectional through-flow passive module of the damping excitation unit fails, the bypass mode is entered.

[0027] The application also provides a current breaking module, comprising at least two passive current breaking devices, and the at least two passive current breaking devices are connected in series.

[0028] The application also provides a current breaking control method, applying the passive current breaking device, comprising the following steps:

[0029] When the system is not faulty, the initial state of the passive current breaking device is closed, current flows through the through-flow branch, the mechanical switch of the through-flow branch is in a closed state, and the bidirectional through-flow passive module of the damping excitation unit works in a bypass mode.

[0030] When the system is faulty, the passive current breaking device receives a breaking instruction:

[0031] The mechanical switch of the through-flow branch is opened, and the damping excitation unit is controlled to switch from the bypass mode to the through-flow mode.

[0032] When the mechanical switch is separated to an insulating separation position, the damping excitation unit is controlled to switch from the through-flow mode to the oscillation mode, the voltage of the damping excitation unit is generated by using line current, the oscillation capacitor and the oscillation inductor of the oscillation branch are excited to oscillate, so that the oscillation branch generates an oscillation current which is equal in amplitude and opposite in direction to the fault current, and the oscillation current makes the mechanical switch of the through-flow branch appear a zero point breaking.

[0033] When the current is transferred to the oscillation branch, the damping excitation unit is controlled to switch from the oscillation mode to the through-flow mode, the fault current starts to charge the oscillation capacitor of the oscillation branch, when the voltage of the oscillation capacitor is greater than the residual voltage of the arrester of the energy dissipation branch, the fault current starts to transfer to the energy dissipation branch and dissipate to zero, the breaking is successful, and the breaking operation is ended.

[0034] The application also provides a current breaking control method, applying the passive current breaking device, comprising the following steps:

[0035] When the system is not faulty, the initial state of the passive current breaking device is closed, current flows through the through-flow branch, the mechanical switch of the through-flow branch is in a closed state, and the bidirectional through-flow passive module of the damping excitation unit works in a bypass mode.

[0036] When the system is faulty, the passive current breaking device receives a breaking instruction:

[0037] The mechanical switch of the through-flow branch is opened;

[0038] When the mechanical switch is separated to the insulating split position, the damping excitation unit is switched from the through-flow mode to the oscillation mode, the voltage of the damping excitation unit is generated by using the line current, the oscillation capacitor and the oscillation inductor of the oscillation branch are excited to oscillate, so that the oscillation branch generates the oscillation current which is equal to the fault current in amplitude and opposite in direction, and the mechanical switch of the through-flow branch appears the zero-crossing opening.

[0039] When the current is transferred to the oscillation branch, the damping excitation unit is switched from the oscillation mode to the through-flow mode, the fault current starts to charge the oscillation capacitor of the oscillation branch, when the voltage of the oscillation capacitor is greater than the residual voltage of the lightning arrester of the energy consumption branch, the fault current starts to transfer to the energy consumption branch and dissipate to zero, the switching is successful and the switching operation is ended.

[0040] The application has the following beneficial effects:

[0041] The passive current breaking device provided by the application comprises a through-flow branch, an oscillation branch and an energy consumption branch.

[0042] The application provides a current breaking module comprising at least two passive current breaking devices connected in series.

[0043] The application provides a current breaking control method. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without creative labor.

[0045] Figure 1 is a circuit structure diagram of a first embodiment of a passive current breaking device of the present application;

[0046] Figure 2 is a circuit structure diagram of a second embodiment of a passive current breaking device of the present application;

[0047] Figure 3 is a circuit structure diagram of a third embodiment of a passive current breaking device of the present application;

[0048] Figure 4a is a circuit structure diagram of a first specific example of a bidirectional current flowing passive module with bypass function in the embodiments of the present application;

[0049] Figure 4b is a circuit structure diagram of a second specific example of a bidirectional current flowing passive module with bypass function in the embodiments of the present application;

[0050] Figure 4c is a circuit structure diagram of a third specific example of a bidirectional current flowing passive module with bypass function in the embodiments of the present application;

[0051] Figure 4d is a circuit structure diagram of a fourth specific example of a bidirectional current flowing passive module with bypass function in the embodiments of the present application;

[0052] Figure 5a is a circuit structure diagram of a first embodiment of a damping excitation unit in the embodiments of the present application;

[0053] Figure 5b is a circuit structure diagram of a second embodiment of a damping excitation unit in the embodiments of the present application;

[0054] Figure 6 is a structure schematic diagram of a current breaking module of the present application;

[0055] Figure 7 is a flow chart of a current breaking control method of the present application;

[0056] Figure 8a is a current flow direction schematic diagram of a current breaking control method of the present application;

[0057] Figure 8bA current flow diagram of a current breaking control method of the present application;

[0058] Figure 8c A current flow diagram of a current breaking control method of the present application;

[0059] Figure 8d A current flow diagram of a current breaking control method of the present application;

[0060] Figure 9 A flow chart of another current breaking control method of the present application;

[0061] Figure 10a A current flow diagram of another current breaking control method of the present application;

[0062] Figure 10b A current flow diagram of another current breaking control method of the present application;

[0063] Figure 10c A current flow diagram of another current breaking control method of the present application;

[0064] Figure 10d A current flow diagram of another current breaking control method of the present application.

[0065] Reference signs:

[0066] 1 - through-flow branch, 11 - mechanical switch, 12 - damping excitation unit, 2 - oscillation branch, 21 - oscillation capacitor, 22 - oscillation inductor, 3 - energy dissipation branch. DETAILED DESCRIPTION

[0067] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application. In addition, in the description of the present application, the term "comprises" means "comprises but is not limited to". In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0068] The present application provides a passive current breaking device, a current breaking module and a current breaking control method. The following will be described in detail. It should be noted that the description order of the following embodiments is not limited as the preferred order of the embodiments.

[0069] As shown in Figure 1 , a passive current breaking device of the first embodiment of the present application comprises:

[0070] a through-flow branch 1 composed of a mechanical switch 11 and a damping excitation unit 12 connected in series;

[0071] an oscillation branch 2 composed of an oscillation capacitor 21 and an oscillation inductor connected in series, the oscillation branch 2 being connected in parallel with the through-flow branch 1;

[0072] an energy consumption branch 3 connected in parallel with the oscillation branch 2.

[0073] As shown in the figure, a passive current breaking device according to a second embodiment of the present application comprises: Figure 2 a through-flow branch 1 composed of a mechanical switch 11 and a damping excitation unit 12 connected in series;

[0074] an oscillation branch 2 composed of an oscillation capacitor 21 and an oscillation inductor connected in series, the oscillation branch 2 being connected in parallel with the through-flow branch 1;

[0075] an energy consumption branch 3 connected in parallel with the oscillation capacitor 21.

[0076] As shown in the figure, a passive current breaking device according to a third embodiment of the present application comprises:

[0077] a through-flow branch 1 composed of a mechanical switch 11 and a damping excitation unit 12 connected in series; Figure 3 an oscillation branch 2 composed of an oscillation capacitor 21 and an oscillation inductor connected in series, the oscillation branch 2 being connected in parallel with the through-flow branch 1;

[0078] an energy consumption branch 3 connected in parallel with the mechanical switch 11.

[0079] In some embodiments, the damping excitation unit 12 is composed of at least one bidirectional through-flow passive module with bypass function.

[0080] As shown in the figure, a bidirectional through-flow passive module with bypass function according to a first embodiment of the present application comprises a first power electronic switch, a second power electronic switch, a first bypass switch and a first resistor, the negative pole of the first power electronic switch being connected with the negative pole of the second power electronic switch, the positive pole of the first power electronic switch leading out a first external wire, the positive pole of the second power electronic switch leading out a second external wire, the first bypass switch and the first resistor being connected in parallel between the first external wire and the second external wire respectively.

[0081]

[0082] As shown in the figure, a bidirectional through-flow passive module with bypass function according to a second embodiment of the present application comprises a first power electronic switch, a second power electronic switch, a first bypass switch and a first resistor, the negative pole of the first power electronic switch being connected with the negative pole of the second power electronic switch, the positive pole of the first power electronic switch leading out a first external wire, the positive pole of the second power electronic switch leading out a second external wire, the first bypass switch and the first resistor being connected in parallel between the first external wire and the second external wire respectively. Figure 4a ​​

[0083] As shown in Figure 4b The second embodiment of the bidirectional current-passing passive module with bypass function of the present application comprises a third power electronic switch, a fourth power electronic switch, a second bypass switch and a second resistor, the negative pole of the third power electronic switch is connected with the positive pole of the fourth power electronic switch to lead out a third external wire, the positive pole of the third power electronic switch is connected with the negative pole of the fourth power electronic switch to lead out a fourth external wire, and the second bypass switch and the second resistor are connected in parallel between the third external wire and the fourth external wire.

[0084] As shown in Figure 4c The third embodiment of the bidirectional current-passing passive module with bypass function of the present application comprises a fifth power electronic switch, a sixth power electronic switch, a seventh power electronic switch, an eighth power electronic switch, a third bypass switch and a third resistor, the positive pole of the fifth power electronic switch is connected with the positive pole of the seventh power electronic switch and the third resistor, the negative pole of the fifth power electronic switch is connected with the positive pole of the sixth power electronic switch to lead out a fifth external wire, the negative pole of the sixth power electronic switch is connected with the negative pole of the eighth power electronic switch and the other end of the third resistor, the negative pole of the seventh power electronic switch is connected with the positive pole of the eighth power electronic switch to lead out a sixth external wire, and the third bypass switch is connected in parallel between the fifth external wire and the sixth external wire.

[0085] As shown in Figure 4d The fourth embodiment of the bidirectional current-passing passive module with bypass function of the present application comprises a ninth power electronic switch, a first diode, a second diode, a third diode, a fourth diode, a fourth bypass switch and a fourth resistor, the first diode, the second diode, the third diode and the fourth diode constitute a diode full-bridge, the positive pole and the negative pole of the ninth power electronic switch are connected with the positive pole and the negative pole of the direct current side of the diode full-bridge respectively, the fourth resistor is connected in parallel between the two ends of the ninth power electronic switch, the alternating current side of the diode full-bridge leads out a seventh external wire and an eighth external wire, and the fourth bypass switch is connected in parallel between the seventh external wire and the eighth external wire.

[0086] In some embodiments, 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 and the ninth power electronic switch are all composed of at least one series-connected full-control power semiconductor device, and the full-control power semiconductor device is one or any combination of IGBT, IEGT, IGCT, MOSFET and GTO.

[0087] In some embodiments, the first diode, the second diode, the third diode, and the fourth diode are each formed by at least one series of uncontrolled power semiconductor devices, which are one or any combination of rectifier diodes and fast recovery diodes.

[0088] In some embodiments, the first resistor, the second resistor, the third resistor, and the fourth resistor are each formed by at least one series-parallel resistor, which is one or any combination of nonlinear resistors and linear resistors.

[0089] As shown in FIG. 12, in some embodiments, the damping excitation unit 12 can be formed by one or more series of bidirectional current-passing passive modules with bypass functions. Other structures of bidirectional current-passing passive modules can also form the damping excitation unit 12 through series connection of the modules. Figure 5a As shown in FIG. 13, in some embodiments, the power electronic switches, diodes, and resistors inside the bidirectional current-passing passive modules of the damping excitation unit 12 are formed by a plurality of series connections. Other structures of bidirectional current-passing passive modules can also form the damping excitation unit 12 through series connection of the internal devices.

[0090] Figure 5b As shown in FIG. 14, in some embodiments, the mechanical switch 11 of the current-passing branch 1 is formed by one or more series-parallel mechanical switches 11, which are usually fast switches and can be electromagnetic repulsion, permanent magnet, or explosion principle mechanical switches 11. When multiple fast switches are connected in series, an RC circuit is usually connected in parallel to improve the voltage equalization performance between the break points.

[0091] The oscillation capacitor 21 of the oscillation branch 2 is formed by one or more series-parallel capacitors, which are usually several uf or several dozen uf and have high voltage resistance and small volume.

[0092] The oscillation inductor 22 of the oscillation branch 2 is formed by one or more series-parallel inductors.

[0093] The energy consumption branch 3 is formed by one or more series-parallel arresters.

[0094] In some embodiments, the working modes of the damping excitation unit 12 include a bypass mode, a current-passing mode, and an oscillation mode.

[0095] In the bypass mode, the bypass switch of the bidirectional current-passing passive module of the damping excitation unit 12 is closed, and the power electronic switch is closed.

[0096] In the current-passing mode, the bypass switch of the bidirectional current-passing passive module of the damping excitation unit 12 is opened, and the power electronic switch is turned on.

[0097] In the current-passing mode, the bypass switch of the bidirectional current-passing passive module of the damping excitation unit 12 is opened, and the power electronic switch is turned on.

[0098] ​The bypass switch of the bidirectional current flow passive module of the damping excitation unit 12 is opened in the oscillation mode, the output characteristics of the bidirectional current flow passive module are controlled through the power electronic switch, and the bidirectional current flow passive module frequently switches between the low-resistance state and the high-resistance state.

[0099] When the bidirectional current flow passive module of the damping excitation unit 12 fails, the bypass mode is entered.

[0100] When the damping excitation unit 12 is in the bypass mode and the current flow mode, the line current can be used.

[0101] When the damping excitation unit 12 is in the oscillation mode, the line current and the passive module characteristic change can be used to output an oscillation voltage.

[0102] By controlling the bidirectional current flow passive module of the damping excitation unit 12, the damping excitation unit 12 can be switched between different resistance characteristics in the oscillation mode at a high frequency, and then a high-frequency oscillation voltage can be output by using the line current.

[0103] As shown in Figure 6 The application provides a passive current breaking module, which comprises a plurality of passive current breaking devices, and the plurality of passive current breaking devices are connected in series.

[0104] The application also provides a passive power breaking control method, which is mainly applied to the passive power breaking device.

[0105] As shown in Figure 7 , a flowchart of an embodiment of the passive power breaking control method of the application is shown. Figure 7 A current flow direction diagram corresponding to the control method is shown. Figure 8a - Figure 8d A current flow direction diagram corresponding to the control method is shown.

[0106] Specifically, when the system does not fail, the initial state of the passive current breaking device is closed, the current flows through the current flow branch, the mechanical switch of the current flow branch is in a closed state, the bidirectional current flow passive module of the damping excitation unit works in the bypass mode, the current flow direction is shown in Figure 8a , and the damping excitation unit does not need to be configured with water cooling or air cooling measures; when the system fails, the passive current breaking device receives a breaking instruction:

[0107] S1: open the mechanical switch of the current flow branch, and control the damping excitation unit to switch from the bypass mode to the current flow mode, and the current flow direction is shown in Figure 8b

[0108] ​S2: When the mechanical switch is opened to the insulating split position, the control damping excitation unit is switched from the through-flow mode to the oscillation mode, the line current is used to generate the voltage of the damping excitation unit, the oscillation capacitor and the oscillation inductor of the oscillation branch are excited to oscillate, so that the oscillation branch generates an oscillation current equal in amplitude and opposite in direction to the fault current, and the oscillation current causes the mechanical switch of the through-flow branch to appear zero-crossing opening, and the current flow is as shown in Figure 8c ;

[0109] S3: After the current is transferred to the oscillation branch, the control damping excitation unit is switched from the oscillation mode to the through-flow mode, the fault current starts to charge the oscillation capacitor of the oscillation branch, and when the voltage of the oscillation capacitor is greater than the residual voltage of the arrester of the energy consumption branch, the fault current starts to transfer to the energy consumption branch and dissipate to zero, and the current flow is as shown in Figure 8d , the switching is successful and the switching operation is ended.

[0110] As shown in Figure 9 , it is a flow chart of another embodiment of the passive power opening control method of the present application. Figure 9 It is a current flow schematic diagram corresponding to the control method. Figure 10a - Figure 10d

[0111] Specifically, when the system is not faulty, the initial state of the passive current opening device is the closed position, the current flows through the through-flow branch, the mechanical switch of the through-flow branch is in the closed state, and the bidirectional through-flow passive module of the damping excitation unit works in the through-flow mode, and the current flow is as shown in Figure 10a , the damping excitation unit needs to be configured with water cooling or air cooling measures; when the system is faulty, the passive current opening device receives a switching-off instruction:

[0112] S1: Open the mechanical switch of the through-flow branch, and the current flow is as shown in Figure 10b ;

[0113] S2: When the mechanical switch is opened to the insulating split position, the control damping excitation unit is switched from the through-flow mode to the oscillation mode, the line current is used to generate the voltage of the damping excitation unit, the oscillation capacitor and the oscillation inductor of the oscillation branch are excited to oscillate, so that the oscillation branch generates an oscillation current equal in amplitude and opposite in direction to the fault current, and the oscillation current causes the mechanical switch of the through-flow branch to appear zero-crossing opening, and the current flow is as shown in Figure 10c ;

[0114] S3: After the current is transferred to the oscillation branch, the control damping excitation unit is switched from the oscillation mode to the through-flow mode, the fault current starts to charge the oscillation capacitor of the oscillation branch, and when the voltage of the oscillation capacitor is greater than the residual voltage of the arrester of the energy consumption branch, the fault current starts to transfer to the energy consumption branch and dissipate to zero, and the current flow is as shown in Figure 10d , the switching is successful and the switching operation is ended.​

[0115] The square wave frequency outputted by the damping excitation unit in the oscillation mode is close to the resonance frequency of the oscillation capacitor and the oscillation inductor of the oscillation branch, and the variable voltage is outputted by the change of the line current and the passive module resistance, so that the current with continuously increasing amplitude can be generated, until the oscillation current with the same amplitude and opposite direction as the fault current is generated, the mechanical switch of the through-flow branch is opened at zero point, and the problems of pre-charging of the capacitor, long breaking time of small current, and significant system oscillation are overcome, so that the passive current breaking device, the current breaking module and the current breaking control method are beneficial to the large-scale promotion and application in the AC and DC power transmission and distribution system.

[0116] In summary, the passive current breaking device, the current breaking module and the current breaking control method of the present application can control the running state of the internal elements of the through-flow branch when the current breaking device is tripped, the damping excitation unit uses the line current and the output voltage of the passive module to generate the oscillation current with the same amplitude and opposite direction as the fault current, so that the mechanical switch is naturally opened at zero point, the problems of pre-charging of the capacitor, long breaking time of small current, significant system oscillation and high equipment cost are overcome, and the passive current breaking device, the current breaking module and the current breaking control method are beneficial to the large-scale promotion and application in the AC and DC power transmission and distribution system.

[0117] The above embodiments only illustrate the technical idea of the present application, and cannot limit the protection scope of the present application. It should be understood by those skilled in the art that any modification or equivalent replacement of the specific embodiments of the present application without departing from the technical idea and scope of the present application should be covered in the scope of the claims of the present application.

Claims

1. A passive current interrupt device, characterized by: Comprise: a through-flow branch (1) composed of a mechanical switch (11) and a damping excitation unit (12) in series; an oscillation branch (2) composed of an oscillation capacitor (21) and an oscillation inductor (22) in series, the oscillation branch (2) being connected in parallel with the through-flow branch (1); an energy consumption branch (3) connected in parallel with the oscillation branch (2), or connected in parallel with the oscillation capacitor (21), or connected in parallel with the mechanical switch (11); the damping excitation unit (12) is composed of at least one bidirectional through-flow passive module with bypass function in series; wherein the bidirectional through-flow passive module comprises a first power electronic switch, a second power electronic switch, a first bypass switch and a first resistor, the negative pole of the first power electronic switch is connected with the negative pole of the second power electronic switch, the positive pole of the first power electronic switch leads to a first external wire, the positive pole of the second power electronic switch leads to a second external wire, the first bypass switch and the first resistor are connected in parallel between the first external wire and the second external wire; or the bidirectional through-flow passive module comprises a third power electronic switch, a fourth power electronic switch, a second bypass switch and a second resistor, the negative pole of the third power electronic switch is connected with the positive pole of the fourth power electronic switch to lead to a third external wire, the positive pole of the third power electronic switch is connected with the negative pole of the fourth power electronic switch to lead to a fourth external wire, the second bypass switch and the second resistor are connected in parallel between the third external wire and the fourth external wire; or the bidirectional through-flow passive module comprises a fifth power electronic switch, a sixth power electronic switch, a seventh power electronic switch, an eighth power electronic switch, a third bypass switch and a third resistor, the positive pole of the fifth power electronic switch is connected with the positive pole of the seventh power electronic switch and the third resistor, the negative pole of the fifth power electronic switch is connected with the positive pole of the sixth power electronic switch to lead to a fifth external wire, the negative pole of the sixth power electronic switch is connected with the negative pole of the eighth power electronic switch and the other end of the third resistor, the negative pole of the seventh power electronic switch is connected with the positive pole of the eighth power electronic switch to lead to a sixth external wire, the third bypass switch is connected in parallel between the fifth external wire and the sixth external wire; or the bidirectional through-flow passive module comprises a ninth power electronic switch, a first diode, a second diode, a third diode, a fourth diode, a fourth bypass switch and a fourth resistor, the first diode, the second diode, the third diode and the fourth diode constitute a diode full-bridge, the positive pole and the negative pole of the ninth power electronic switch are connected with the positive pole and the negative pole of the direct current side of the diode full-bridge respectively, the fourth resistor is connected in parallel between the two ends of the ninth power electronic switch, the alternating current side of the diode full-bridge leads to a seventh external wire and an eighth external wire, the fourth bypass switch is connected in parallel between the seventh external wire and the eighth external wire.

2. The passive current breaking device according to claim 1, wherein: 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 are each composed of at least one fully controllable power semiconductor device in series, the fully controllable power semiconductor device being one or any combination of IGBT, IEGT, IGCT, MOSFET, GTO.

3. The passive current breaking device according to claim 1, wherein: the first diode, the second diode, the third diode, the fourth diode are each composed of at least one non-controllable power semiconductor device in series, the non-controllable power semiconductor device being one or any combination of rectifier diode, fast recovery diode.

4. The passive current breaking device according to claim 1, wherein: the first resistor, the second resistor, the third resistor, the fourth resistor are each composed of at least one resistor in series and parallel, the resistor being one or any combination of non-linear resistor, linear resistor.

5. The passive current breaking device according to claim 1, wherein: the mechanical switch (11) is composed of one or more mechanical switches (11) in series and parallel; and / or the oscillation capacitor (21) is composed of one or more capacitors in series and parallel; and / or the oscillation inductor (22) is composed of one or more inductors in series and parallel; and / or the energy dissipation branch (3) is composed of one or more arresters in series and parallel.

6. The passive current interrupt device of claim 1, wherein: The oscillation capacitor is a pulse capacitor.

7. The passive current breaking device according to claim 1, wherein: the working mode of the damping excitation unit (12) includes bypass mode, through-flow mode and oscillation mode; in the bypass mode, the bypass switch and the power electronic switch of the bidirectional through-flow passive module of the damping excitation unit (12) are closed; in the through-flow mode, the bypass switch of the bidirectional through-flow passive module of the damping excitation unit (12) is opened, and the power electronic switch is turned on; in the oscillation mode, the bypass switch of the bidirectional through-flow passive module of the damping excitation unit (12) is opened, and the output characteristic of the bidirectional through-flow passive module is controlled by the power electronic switch, the bidirectional through-flow passive module switches between low resistance and high resistance states; when the bidirectional through-flow passive module of the damping excitation unit (12) fails, the bypass mode is entered.

8. An electrical current interruption module, characterized by: The application comprises at least two passive current breaking devices according to any one of claims 1-7, and at least two of the passive current breaking devices are connected in series.

9. A current interruption control method, characterized by: The application of the passive current breaking device according to any one of claims 1-7 comprises the following steps: when the system is not faulty, the initial state of the passive current breaking device is closed, the current flows through the through-flow branch, the mechanical switch of the through-flow branch is in the closed state, and the bidirectional through-flow passive module of the damping excitation unit works in the bypass mode; When the system fails, the passive current breaking device receives a tripping instruction: Open the mechanical switch of the through-flow branch, and control the damping excitation unit to switch from the bypass mode to the through-flow mode; When the mechanical switch is separated to the insulated separation position, control the damping excitation unit to switch from the through-flow mode to the oscillation mode, generate the voltage of the damping excitation unit by using the line current, excite the oscillation capacitor and the oscillation inductor of the oscillation branch to oscillate, so that the oscillation branch generates the oscillation current which is equal to the fault current in amplitude and opposite in direction, and the oscillation current makes the mechanical switch of the through-flow branch appear the zero-crossing breaking; When the current is transferred to the oscillation branch, control the damping excitation unit to switch from the oscillation mode to the through-flow mode, the fault current starts to charge the oscillation capacitor of the oscillation branch, when the voltage of the oscillation capacitor is greater than the residual voltage of the arrester of the energy consumption branch, the fault current starts to transfer to the energy consumption branch and dissipate to zero, the tripping is successful and the tripping operation is ended.

10. A current interruption control method, characterized by: The passive current breaking device according to any one of claims 1-7, comprising the following steps: When the system fails, the passive current breaking device receives a tripping instruction: Open the mechanical switch of the through-flow branch; When the mechanical switch is separated to the insulated separation position, control the damping excitation unit to switch from the through-flow mode to the oscillation mode, generate the voltage of the damping excitation unit by using the line current, excite the oscillation capacitor and the oscillation inductor of the oscillation branch to oscillate, so that the oscillation branch generates the oscillation current which is equal to the fault current in amplitude and opposite in direction, and the oscillation current makes the mechanical switch of the through-flow branch appear the zero-crossing breaking; When the current is transferred to the oscillation branch, control the damping excitation unit to switch from the oscillation mode to the through-flow mode, the fault current starts to charge the oscillation capacitor of the oscillation branch, when the voltage of the oscillation capacitor is greater than the residual voltage of the arrester of the energy consumption branch, the fault current starts to transfer to the energy consumption branch and dissipate to zero, the tripping is successful and the tripping operation is ended. ​

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