Direct current circuit breaker having adjustable oscillating current and control method therefor, system, device, and storage medium

Abstract

The present application discloses a direct current circuit breaker having an adjustable oscillating current and a control method therefor, a system, a device, and a storage medium. The direct current circuit breaker having an adjustable oscillating current comprises a first mechanical switch, a regulation and control unit, an oscillation unit, and a surge arrester unit. The first mechanical switch is connected in series with the regulation and control unit to form a through-current branch, and the through-current branch, the oscillation unit and the surge arrester unit are connected in parallel. The oscillation unit is used for generating an oscillating current and injecting the oscillating current into the first mechanical switch. The regulation and control unit is used for regulating the oscillating current. The surge arrester unit is used for limiting the voltage of the direct current circuit breaker and dissipating the breaking energy of the direct current circuit breaker. The present application can achieve the regulation and control of the oscillating current, and then the oscillating current can cause the current flowing through the first mechanical switch to generate a zero-crossing point, so that the direct current circuit breaker is disconnected, thereby improving the flexibility and operation reliability of the direct current circuit breaker.

Description

A DC circuit breaker with adjustable oscillating current, and its control method, system, equipment, and storage medium.

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202410783875.7, filed on June 18, 2024, entitled "A DC Circuit Breaker with Adjustable Oscillating Current and a Control Method Thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of DC power transmission and distribution, specifically to a DC circuit breaker with adjustable oscillation current and its control method, system, equipment, and storage medium. Background Technology

[0004] With the rapid development of renewable energy technologies such as wind power and photovoltaics, DC transmission and distribution systems (which can be either DC transmission systems or DC distribution systems) for large-scale consumption of renewable energy have been widely used. To make DC transmission and distribution systems more economical and flexible, DC circuit breakers are often installed on DC lines.

[0005] Existing technology provides DC circuit breakers that achieve interruption by pre-charging the capacitor in the oscillation unit to create a current zero point for the mechanical switch. However, with increasing voltage levels, the voltage and capacity of the capacitor and the equipment charging it increase significantly, making it difficult for DC circuit breakers to interrupt small currents, thus resulting in relatively low flexibility and operational reliability. Summary of the Invention

[0006] To address the issues of low flexibility and operational reliability in existing DC circuit breakers, this application provides a DC circuit breaker with adjustable oscillation current, which may include a first mechanical switch, a control unit, an oscillation unit, and a surge arrester unit. The first mechanical switch and the control unit are connected in series to form a current-carrying branch, and the current-carrying branch, the oscillation unit, and the surge arrester unit are connected in parallel.

[0007] The oscillation unit is used to: generate an oscillating current and inject the oscillating current into the first mechanical switch.

[0008] The control unit is used to control the oscillation current.

[0009] The surge arrester unit is used to: limit the voltage of the DC circuit breaker and dissipate the breaking energy of the DC circuit breaker.

[0010] Optionally, the control unit includes a control circuit. The control circuit includes a full-bridge structure and a control branch. Alternatively, the control circuit includes a full-bridge structure, a current-carrying branch, and a control branch, with the current-carrying branch and the control branch connected in parallel.

[0011] The entire bridge structure includes a first bridge arm, a second bridge arm, a third bridge arm, and a fourth bridge arm. The first and second bridge arms are connected to form the first end of the entire bridge structure, and the third and fourth bridge arms are connected to form the second end of the entire bridge structure. The first bridge arm is also connected to the third bridge arm, and the second bridge arm is also connected to the fourth bridge arm.

[0012] The first end of the control branch is connected between the first and third bridge arms, and the second end of the control branch is connected between the second and fourth bridge arms.

[0013] In some possible implementations, the control branch includes a first diode, a first fully controllable semiconductor device, a resistor, and a first capacitor.

[0014] The anode of the first diode serves as the first terminal of the control branch. The cathode of the first diode is connected to the first terminal of the first fully controllable semiconductor device and the first terminal of the first capacitor. The second terminal of the first fully controllable semiconductor device is connected to the first terminal of the resistor, and the second terminal of the first capacitor is connected to the second terminal of the resistor, serving as the second terminal of the control branch.

[0015] Optionally, the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm all employ a second fully controlled semiconductor device.

[0016] For example, the current-carrying branch includes a third fully controlled semiconductor device. The first, second, third, and fourth bridge arms all employ a second diode.

[0017] In some possible implementations, the control unit also includes a second mechanical switch. The second mechanical switch is connected in parallel with the control circuit.

[0018] Optionally, the oscillation unit includes an inductor and a second capacitor connected in series.

[0019] Furthermore, this application also provides a control method for a DC circuit breaker, which may include: controlling the first mechanical switch to open, and regulating the oscillating current generated by the oscillating unit through a regulating unit. When the amplitude of the oscillating current is equal to the amplitude of the short-circuit current of the DC circuit breaker and the direction of the oscillating current is opposite to the direction of the short-circuit current, the short-circuit current is transferred to the oscillating unit to charge the oscillating unit, and the first mechanical switch completes the opening. When the voltage of the oscillating unit rises to the operating voltage of the surge arrester unit in the DC circuit breaker, the surge arrester unit dissipates the breaking energy of the DC circuit breaker.

[0020] Optionally, the control method further includes: when the direction of the oscillating current is opposite to the direction of the short-circuit current, controlling the third fully controlled semiconductor device in the control unit to turn off, and controlling the first fully controlled semiconductor device in the control unit to turn off according to the turn-off time, so as to charge the first capacitor in the control unit through the short-circuit current. When the direction of the oscillating current is the same as the direction of the short-circuit current, controlling both the first fully controlled semiconductor device and the third fully controlled semiconductor device to turn on, and the first capacitor discharges through the resistor.

[0021] Furthermore, the control method determines the turn-off time according to the following procedure:

[0022] The target voltage of the first capacitor is determined based on the preset current safety factor and the number of half-wave oscillations.

[0023] The voltage change of the first capacitor is determined based on the capacitance value, short-circuit current, and oscillating current.

[0024] The conduction time of the first fully controllable semiconductor device is determined based on the target voltage of the first capacitor and the voltage change of the first capacitor, and the turn-off time is determined based on the conduction time.

[0025] Furthermore, this application also provides a DC power transmission and distribution system, which may include the aforementioned DC circuit breaker.

[0026] Compared with the prior art, the beneficial effects of this application are as follows:

[0027] The DC circuit breaker with adjustable oscillation current provided in this application can regulate the oscillation current through a control unit. This oscillation current can then cause the current flowing through the first mechanical switch to cross zero, thereby opening the DC circuit breaker. It can be seen that this application improves the flexibility and operational reliability of the DC circuit breaker by regulating the oscillation current.

[0028] This application uses a control unit to regulate the oscillating current, thereby realizing the opening and closing of the DC circuit breaker. This significantly reduces the number of semiconductor devices in the DC circuit breaker and also reduces the capacitance value of the first capacitor in the control unit, thereby reducing the cost of the DC circuit breaker.

[0029] The control unit in this application can inject energy into the oscillation unit by controlling the oscillation current, which greatly improves the oscillation efficiency.

[0030] The control unit in this application can draw energy from the DC line to provide the energy required for the operation of the first mechanical switch, the second mechanical switch, and the fully controlled semiconductor device, thereby reducing the number and volume of DC circuit breakers and lowering the overall cost of DC circuit breakers. Attached Figure Description

[0031] Figure 1 is a schematic flowchart of a DC circuit breaker with adjustable oscillation current in an embodiment of this application;

[0032] Figure 2 is a schematic structural diagram of a control circuit in an embodiment of this application;

[0033] Figure 3 is a schematic structural diagram of a control unit in an embodiment of this application;

[0034] Figure 4 is a schematic structural diagram of a control unit in an embodiment of this application;

[0035] Figure 5 is another schematic structural diagram of the control circuit in the embodiment of this application;

[0036] Figure 6 is a schematic flowchart of a control method for a DC circuit breaker 100 with adjustable oscillation current in an embodiment of this application;

[0037] Figure 7 is a schematic structural diagram of a DC circuit breaker with adjustable oscillation current in an embodiment of this application;

[0038] Figure 8a is a schematic diagram of one flow direction of short-circuit current in an embodiment of this application;

[0039] Figure 8b is a schematic diagram of the flow direction of oscillating current and short-circuit current in an embodiment of this application;

[0040] Figure 8c is a schematic diagram of the flow direction of oscillating current and short-circuit current in an embodiment of this application;

[0041] Figure 8d is a schematic diagram of the flow direction of oscillating current and short-circuit current in an embodiment of this application;

[0042] Figure 8e is a schematic diagram of one flow direction of short-circuit current in an embodiment of this application;

[0043] Figure 8f is a schematic diagram of one flow direction of short-circuit current in an embodiment of this application. Detailed Implementation

[0044] This application provides a DC circuit breaker with adjustable oscillation current, as shown in Figure 1. The DC circuit breaker 100 may include a first mechanical switch 10, a control unit 30, an oscillation unit 20, and a surge arrester unit 40. The first mechanical switch 10 and the control unit 30 are connected in series to form a current-carrying branch. The current-carrying branch, the oscillation unit 20, and the surge arrester unit 40 are connected in parallel.

[0045] The oscillation unit 20 is used to: generate an oscillation current and inject the oscillation current into the first mechanical switch 10.

[0046] The control unit 30 is used to control the oscillation current.

[0047] The surge arrester unit 40 is used to: limit the voltage of the DC circuit breaker 100 and dissipate the breaking energy of the DC circuit breaker 100.

[0048] Optionally, as shown in Figure 1, the oscillation unit 20 includes an inductor L and a second capacitor R2 connected in series.

[0049] As shown in Figure 2, the control unit 30 can be an ultra-high-speed control arc-free control unit, including a control circuit 31. The ultra-high-speed control arc-free control unit does not require commutation and is simple to operate, but it requires a water-cooling system.

[0050] In one example, as shown in Figure 3, the control circuit 31 includes a full-bridge structure and a control branch 311. Referring to Figure 3, the full-bridge structure includes a first bridge arm, a second bridge arm, a third bridge arm, and a fourth bridge arm. The first and second bridge arms are connected to form the first end of the full-bridge structure, and the third and fourth bridge arms are connected to form the second end of the full-bridge structure. The first bridge arm is also connected to the third bridge arm, and the second bridge arm is also connected to the fourth bridge arm.

[0051] The first end of the control branch 311 is connected between the first bridge arm and the third bridge arm, and the second end of the control branch 311 is connected between the second bridge arm and the fourth bridge arm.

[0052] As shown in Figure 3, the first bridge arm, the second bridge arm, the third bridge arm and the fourth bridge arm all use the second fully controlled semiconductor device, namely T21, T22, T23 and T24 in Figure 3.

[0053] Optionally, diodes are connected in anti-parallel to T21, T22, T23, and T24. For example, diode D21 can be connected in anti-parallel to T21, diode D22 to T22, diode D23 to T23, and diode D24 to T24.

[0054] The control branch 311 includes a first diode D1, a first fully controllable semiconductor device T1, a resistor R, and a first capacitor C1. The first fully controllable semiconductor device T1, as well as T21, T22, T23, and T24, can all be integrated gate-commutated thyristors (IGCT), insulated gate bipolar transistors (IGBT), or IGBT series electronic devices with a withstand voltage of 4KV or higher (IGT).

[0055] The anode of the first diode D1 serves as the first terminal of the control branch 311. The cathode of the first diode D1 is connected to the first terminal of the first fully controllable semiconductor device T1 and the first terminal of the first capacitor C1. The second terminal of the first fully controllable semiconductor device T1 is connected to the first terminal of the resistor R, and the second terminal of the first capacitor C1 is connected to the second terminal of the resistor R, serving as the second terminal of the control branch 311.

[0056] In another example, as shown in Figure 4, the control circuit 31 includes a full-bridge structure, a current-carrying branch 312, and a control branch 311. The current-carrying branch 312 and the control branch 311 are connected in parallel. In Figure 4, the full-bridge structure also includes a first bridge arm, a second bridge arm, a third bridge arm, and a fourth bridge arm. The first bridge arm and the second bridge arm are connected to form the first end of the full-bridge structure, and the third bridge arm and the fourth bridge arm are connected to form the second end of the full-bridge structure. The first bridge arm is also connected to the third bridge arm, and the second bridge arm is also connected to the fourth bridge arm.

[0057] The first end of the control branch 311 is connected between the first bridge arm and the third bridge arm, and the second end of the control branch 311 is connected between the second bridge arm and the fourth bridge arm.

[0058] As shown in Figure 4, the first, second, third, and fourth bridge arms all use second diodes, namely D11, D12, D13, and D14 in Figure 4. The control branch 311 includes a first diode D1, a first fully controllable semiconductor device T1, a resistor R, and a first capacitor C1. The anode of the first diode D1 serves as the first terminal of the control branch 311. The cathode of the first diode D1 is connected to the first terminal of the first fully controllable semiconductor device T1 and the first terminal of the first capacitor C1. The second terminal of the first fully controllable semiconductor device T1 is connected to the first terminal of the resistor R, and the second terminal of the first capacitor C1 is connected to the second terminal of the resistor R, serving as the second terminal of the control branch 311.

[0059] For example, the current-carrying branch 312 includes a third fully controllable semiconductor device T3. Optionally, the first fully controllable semiconductor device T1 and the third fully controllable semiconductor device T3 can be IGCT, IGBT, IEGT, etc.

[0060] In some possible implementations, as shown in Figure 5, the control unit 30 further includes a second mechanical switch 32. The second mechanical switch 32 is connected in parallel with the control circuit 31. The control unit 30, including the control circuit 31 and the second mechanical switch 32, can be a low-loss arc-shaped control unit. For the low-loss arc-shaped control unit, the normal current loss is small, but commutation is required in case of failure.

[0061] This application also provides a control method for a DC circuit breaker 100 with adjustable oscillation current. As shown in Figure 6, it may include the following steps:

[0062] Step S1: Control the first mechanical switch 10 to open, and regulate the oscillation current generated by the oscillation unit 20 through the regulation unit 30.

[0063] Step S2: When the amplitude of the oscillating current is equal to the amplitude of the short-circuit current of the DC circuit breaker 100 and the direction of the oscillating current is opposite to the direction of the short-circuit current, the short-circuit current is transferred to the oscillating unit 20 to charge the oscillating unit 20, and the first mechanical switch 10 completes the opening.

[0064] Step S3: When the voltage of the oscillation unit 20 rises to the operating voltage of the surge arrester unit 40 in the DC circuit breaker, the surge arrester unit 40 dissipates the breaking energy of the DC circuit breaker 100.

[0065] Optionally, the control method provided in this application embodiment further includes: when the direction of the oscillating current is opposite to the direction of the short-circuit current, controlling the third fully controlled semiconductor device T3 in the control unit 30 to turn off, and controlling the first fully controlled semiconductor device T1 in the control unit 30 to turn off according to the turn-off time (which can be represented by t), and charging the first capacitor C1 in the control unit 30 through the short-circuit current.

[0066] When the direction of the oscillating current is the same as the direction of the short-circuit current, both the first fully controlled semiconductor device T1 and the third fully controlled semiconductor device T3 are turned on, and the first capacitor C1 is discharged through the resistor R.

[0067] Furthermore, the control method provided in this application embodiment determines the turn-off time t according to the following process:

[0068] 1) Determine the target voltage of the first capacitor C1 based on the preset current safety factor and the number of half-wave oscillations. Specifically, this can be determined based on the expected short-circuit current I of the DC transmission and distribution system. S0 The peak value of the oscillating current I during the interruption process of the DC circuit breaker is determined by the preset current safety factor k0 (k0>1). O0 Expected oscillation current I O0 Satisfying the formula: I O0 =k0I S0 (1)

[0069] Based on the peak value of the oscillation current I O0 The target voltage U of the first capacitor C1 is determined by the number N of the half-wave oscillation. C10 The target voltage U of the first capacitor C1 C10 Satisfying the formula:

[0070] AndU C10 ≤U mWhere Z represents the oscillation impedance of oscillation unit 20, satisfying the formula:

[0071] L represents the inductance value of inductor L in oscillation unit 20, and C2 represents the capacitance value of the second capacitor. m This indicates the maximum withstand voltage of the fully controlled semiconductor device in the control circuit 31.

[0072] 2) Based on the capacitance value C1 of the first capacitor C1 and the short-circuit current i s and oscillating current i o Determine the voltage change ΔuC1n of the first capacitor C1 (n=2,3,4,…;n≤N).

[0073] The voltage change ΔuC1n of the first capacitor C1 satisfies the formula:

[0074] Where, δ t This represents the period of a half-wave oscillation. t 0n The starting time of the counterclockwise flow cycle of the nth half-wave oscillation current can be expressed by the formula: t 0n =t 02 +2(n-2)δ t (5)

[0075] Among them, t 02 This indicates the starting moment of the counterclockwise flow cycle of the second half-wave oscillation current.

[0076] 3) Determine the conduction duration of the first fully controlled semiconductor device T1 based on the target voltage of the first capacitor C1 and the voltage change of the first capacitor C1, and determine the turn-off time based on the conduction duration.

[0077] Specifically, during the on-state phase of the first fully controlled semiconductor device T1, the equivalent discharge circuit of the first capacitor C1 satisfies the following formula:

[0078] Where R represents the resistance value, and Δtn represents the on-time of the first fully controllable semiconductor device T1. Therefore, the off-time of the first fully controllable semiconductor device T1 can be determined based on Δtn.

[0079] The following describes the control method of the DC circuit breaker 100 provided in this application embodiment, taking the control circuit 31 shown in Figure 4 as an example (as shown in Figure 7).

[0080] For the DC circuit breaker 100 shown in Figure 7, before it is put into operation, the second mechanical switch 32 is closed, the first fully controlled semiconductor device T1 and the third fully controlled semiconductor device T3 are turned on, the first mechanical switch 10 is closed, and the short-circuit current is conducted, as shown in Figure 8a. After the DC circuit breaker 100 is closed, the first fully controlled semiconductor device T1 and the third fully controlled semiconductor device T3 are turned off.

[0081] In the event of a short circuit fault in the DC power transmission and distribution system, the DC circuit breaker receives a tripping command, the third fully controlled semiconductor device T3 is turned on, the second mechanical switch 32 is tripped, and the short circuit current is transferred from the second mechanical switch 32 to the control unit 30, as shown in Figure 8b.

[0082] After the current of the second mechanical switch 32 crosses zero, the third fully controlled semiconductor device T3 is turned off. The short-circuit current charges the first capacitor C1. At the same time, the circuit consisting of the first mechanical switch 10-diode D12-first capacitor C1-diode D1-diode D13-second capacitor C2-inductor L generates a counterclockwise oscillating current (i.e., the direction of the oscillating current is opposite to the direction of the short-circuit current), as shown in Figure 8c.

[0083] After a half-wave oscillation period δ t When the counter-clockwise oscillating current drops to zero, the first fully controlled semiconductor device T1 and the third fully controlled semiconductor device T3 are turned on, and the oscillating current changes to a clockwise direction (i.e., the direction of the oscillating current is the same as the direction of the short-circuit current). The current flows through the loop of the first mechanical switch 10 - inductor L - second capacitor C2 - diode D14 - third fully controlled semiconductor device T3 - diode D11. Simultaneously, in the control unit 30, the first capacitor C1 discharges through the first fully controlled semiconductor device T1 to the resistor R, as shown in Figure 8d. During the half-wave of the clockwise oscillating current flow, by controlling the first fully controlled semiconductor device T1 to turn off, the voltage of the first capacitor C1 can be controlled within a preset range.

[0084] After a preset control cycle, the oscillating current reaches an amplitude equal to and opposite in direction to the short-circuit current, and the current of the first mechanical switch 10 crosses zero, extinguishing the arc. Subsequently, the short-circuit current is transferred to the oscillation unit 20 and charges the second capacitor C2, as shown in Figure 8e. The voltage of the second capacitor C2 rises to the operating voltage of the surge arrester unit 40, the short-circuit current is switched to flow in the surge arrester unit 40, the surge arrester unit 40 absorbs the breaking energy, and the short-circuit current breaking is completed, as shown in Figure 8f.

[0085] This application also provides a DC power transmission and distribution system, which may include the DC circuit breaker 10 mentioned above, etc., which will not be described in detail in this application.

[0086] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval. Industrial applicability

[0087] This application provides a DC circuit breaker with adjustable oscillating current, and its control method, system, device, and storage medium. The DC circuit breaker with adjustable oscillating current includes a first mechanical switch, a control unit, an oscillation unit, and a surge arrester unit. The first mechanical switch and the control unit are connected in series to form a current-carrying branch, and the current-carrying branch, the oscillation unit, and the surge arrester unit are connected in parallel. The oscillation unit generates an oscillating current and injects it into the first mechanical switch. The control unit regulates the oscillating current. The surge arrester unit limits the voltage of the DC circuit breaker and dissipates its breaking energy. This application enables the regulation of the oscillating current, which in turn causes the current flowing through the first mechanical switch to cross zero, thus breaking the DC circuit breaker and improving its flexibility and operational reliability.

Claims

1. An oscillation current adjustable DC circuit breaker, comprising a first mechanical switch, a regulation unit, an oscillation unit and a surge arrester unit; the first mechanical switch is connected in series with the regulation unit to form a through-flow branch, and the through-flow branch, the oscillation unit and the surge arrester unit are connected in parallel; the oscillation unit is configured to generate an oscillation current and inject the oscillation current into the first mechanical switch; the regulation unit is configured to regulate the oscillation current; the surge arrester unit is configured to limit the voltage of the DC circuit breaker and dissipate the breaking energy of the DC circuit breaker.

2. The DC circuit breaker according to claim 1, wherein, The regulation unit comprises a regulation circuit; The regulation circuit comprises a full-bridge structure and a regulation branch; or the regulation circuit comprises a full-bridge structure, a current-carrying branch and a regulation branch, and the current-carrying branch is connected in parallel with the regulation branch; The full-bridge structure comprises a first bridge arm, a second bridge arm, a third bridge arm and a fourth bridge arm; the first bridge arm and the second bridge arm are connected to form a first end of the full-bridge structure, the third bridge arm and the fourth bridge arm are connected to form a second end of the full-bridge structure, the first bridge arm is further connected to the third bridge arm, and the second bridge arm is further connected to the fourth bridge arm; A first end of the regulation branch is connected between the first bridge arm and the third bridge arm, and a second end of the regulation branch is connected between the second bridge arm and the fourth bridge arm.

3. The DC circuit breaker according to claim 2, wherein, The regulation branch comprises a first diode, a first fully-controlled semiconductor device, a resistor and a first capacitor; The anode of the first diode serves as the first end of the regulation branch, the cathode of the first diode is connected to a first end of the first fully-controlled semiconductor device and a first end of the first capacitor, a second end of the first fully-controlled semiconductor device is connected to a first end of the resistor, a second end of the first capacitor is connected to a second end of the resistor, and the second end serves as the second end of the regulation branch.

4. The DC circuit breaker according to claim 3, wherein, The first bridge arm, the second bridge arm, the third bridge arm and the fourth bridge arm each adopt a second fully-controlled semiconductor device.

5. The DC circuit breaker according to claim 3, wherein, The current-carrying branch comprises a third fully-controlled semiconductor device.

6. The DC circuit breaker according to claim 5, wherein, The first bridge arm, the second bridge arm, the third bridge arm and the fourth bridge arm each adopt a second diode.

7. The DC circuit breaker according to claim 2, wherein, The regulation unit further comprises a second mechanical switch, and the second mechanical switch is connected in parallel with the regulation circuit.

8. The DC circuit breaker according to claim 1, wherein, The oscillation unit comprises an inductor and a second capacitor connected in series.

9. A control method of an oscillation current adjustable DC circuit breaker, comprising: controlling a first mechanical switch to open, and regulating an oscillation current generated by an oscillation unit through a regulation unit; in a case where an amplitude of the oscillation current is equal to an amplitude of a short-circuit current of the DC circuit breaker and a direction of the oscillation current is opposite to a direction of the short-circuit current, the short-circuit current is transferred to the oscillation unit to charge the oscillation unit, and the first mechanical switch is opened; in a case where a voltage of the oscillation unit rises to an operating voltage of a surge arrester unit in the DC circuit breaker, the surge arrester unit dissipates breaking energy of the DC circuit breaker.

10. The control method according to claim 9, wherein The control method further comprises: In the case that the direction of the oscillation current is opposite to the direction of the short-circuit current, a third controllable semiconductor device in the regulating unit is controlled to be off, and a first controllable semiconductor device in the regulating unit is controlled to be off at the off time, and the first capacitor in the regulating unit is charged by the short-circuit current; In the case that the direction of the oscillation current is same as the direction of the short-circuit current, the first controllable semiconductor device and the third controllable semiconductor device are controlled to be on, and the first capacitor is discharged through a resistor in the regulating unit.

11. The control method according to claim 10, wherein The control method determines the off time according to the following process: The target voltage of the first capacitor is determined according to a preset current safety factor and the number of half-wave oscillations, the voltage variation of the first capacitor is determined according to the capacitance value of the first capacitor, the short-circuit current and the oscillation current, the on duration of the first controllable semiconductor device is determined according to the target voltage of the first capacitor and the voltage variation of the first capacitor, and the off time is determined according to the on duration.

12. A direct current transmission and distribution system comprising the oscillation current adjustable direct current circuit breaker according to any one of claims 1 to 8.

13. A computer readable storage medium, the storage medium storing a computer program, the computer program being used to execute the method according to any one of claims 9 to 11.

14. An electronic device, the electronic device comprising: a processor; a memory for storing executable instructions of the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the method according to any one of claims 9 to 11.

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