Adaptive switching control method for fault current of DC circuit breakers

Abstract

This application discloses an adaptive switching control method for fault current in a DC circuit breaker, relating to the field of power electronics technology. The method includes: the DC circuit breaker comprising a parallel current-carrying branch and an oscillating branch; the method further includes: upon detecting a fault, acquiring fault current information of the current-carrying branch; calculating derivative information of at least one order corresponding to the fault current information based on the fault current information; predicting the predicted fault current of the current-carrying branch at a first preset time based on the derivative information; adjusting the switching time of the oscillating branch using an adaptive control algorithm based on the predicted fault current; and performing switching control on the DC circuit breaker based on the switching time. According to the embodiments of this application, the switching time of the oscillating branch can be adaptively determined, thereby effectively improving the response timeliness and breaking reliability of the DC circuit breaker under various fault scenarios.

Description

Technical Field

[0001] This application belongs to the field of power electronics technology, and in particular relates to an adaptive switching control method for fault current of a DC circuit breaker. Background Technology

[0002] With the development of flexible DC transmission technology and the integration of large-scale renewable energy sources, the power system's requirements for rapid DC fault clearing capabilities are increasing. Currently, DC circuit breakers are mainly classified into three types: mechanical, solid-state, and hybrid. Among them, the hybrid oscillating DC circuit breaker, due to its rapid breaking capacity and economic advantages, is gradually becoming the focus of research and application in DC breaking equipment.

[0003] Hybrid oscillating DC circuit breakers typically consist of parallel current-carrying branches and oscillating branches. When a fault current occurs, the mechanical switch on the current-carrying branch trips, requiring the oscillating branch to engage in conjunction with this tripping to achieve zero-crossing interruption of the current in the current-carrying branch. The zero-crossing time of the current is closely related to the switching time of the oscillating branch. However, currently, the switching time of the oscillating branch is usually fixed, which prevents the DC circuit breaker from accurately achieving zero-crossing interruption when facing different fault current magnitudes. If the switching time is too early, the mechanical switch on the current-carrying branch may not have sufficient post-arc withstand voltage capability; if the switching time is too late, the turn-off time requirement may not be met, thus affecting the fault isolation effect of the DC circuit breaker.

[0004] Therefore, due to the fixed switching time of the oscillating branch, the existing hybrid oscillating DC circuit breaker technology is difficult to achieve precise current zero-crossing interruption under different fault current conditions, and the interruption effect is limited, which restricts the application effect and reliability of DC circuit breakers in flexible DC transmission and large-scale renewable energy access scenarios. Summary of the Invention

[0005] This application provides a fault current adaptive switching control method for a DC circuit breaker, which can adaptively determine the switching time of the oscillating branch, thereby effectively improving the response timeliness and breaking reliability of the DC circuit breaker under various fault scenarios.

[0006] In a first aspect, embodiments of this application provide a fault current adaptive switching control method for a DC circuit breaker. The DC circuit breaker includes a current-carrying branch and an oscillating branch connected in parallel. The fault current adaptive switching control method for the DC circuit breaker includes: If a fault is detected, obtain the fault current information of the current-carrying branch; Based on the fault current information, calculate the derivative information of at least one order corresponding to the fault current information; Based on derivative information, the predicted fault current of the current-carrying branch at the first preset time is predicted; Based on the predicted fault current, the switching time of the oscillation branch is adjusted through an adaptive control algorithm, and the switching control of the DC circuit breaker is performed based on the switching time.

[0007] In some possible implementations, based on the fault current information, the derivative information of at least one order corresponding to the fault current information is calculated, including: Based on the fault current information, calculate the first and / or second derivatives corresponding to the fault current information.

[0008] In some possible implementations, based on derivative information, the predicted fault current of the current-carrying branch at a preset time is predicted, including: Based on derivative information, the predicted fault current at a preset time is predicted through Taylor expansion or difference equations.

[0009] In some possible implementations, a mechanical switch is included on the current-carrying branch; the fault current adaptive switching control method of the DC circuit breaker further includes: If a fault is detected, and the second preset time is reached, a trip command is sent to the DC circuit breaker so that the DC circuit breaker performs a trip operation on the mechanical switch. The second preset time is located before the first preset time, and the second preset time is located before the switching time of the oscillation branch.

[0010] In some possible implementations, the current in the current-carrying branch crosses zero at the target time, and the mechanical switch is used to complete the opening and closing at the target time; The target time is within a preset time range, the minimum time within the preset time range is after the switching time, and the maximum time within the preset time range is either at or before the first preset time.

[0011] In some possible implementations, the time interval required for the mechanical switch to reach the target opening distance from the start of opening is a preset time interval, and the post-arc dielectric recovery capability of the mechanical switch at the target opening distance meets the preset conditions. The time interval between the second preset time and the minimum time within the preset time range is greater than or equal to the preset time interval.

[0012] In some possible implementations, switching control of the DC circuit breaker is performed based on the switching time, including: Based on the switching timing of the oscillation branch, a switching control command is generated; Send a switching control command to the DC circuit breaker so that the DC circuit breaker controls the oscillation branch to be switched on when the switching time is reached.

[0013] In some possible implementations, the fault current adaptive switching control method for the DC circuit breaker further includes the following: (The method is described in the original text, but the translation is incomplete.) The current information in the current-carrying branch is obtained by a current sensor, which is installed in the DC circuit breaker. The current information is compared with a preset current threshold, and a fault is determined to have occurred if the current information exceeds the preset current threshold.

[0014] In some possible implementations, the oscillation branch includes an oscillation inductor, an oscillation capacitor, and an oscillation module, wherein the oscillation module includes a power electronic switch; The oscillating inductor, oscillating capacitor, and oscillating module are connected in series, and the oscillating inductor and oscillating capacitor are arranged adjacent to each other.

[0015] In some possible implementations, the DC circuit breaker also includes an energy-dissipating branch connected in parallel with the current-carrying branch; Metal oxide surge arresters are installed on the energy-consuming branches.

[0016] Based on the same inventive concept, in a second aspect, embodiments of this application provide a fault current adaptive switching control system for a DC circuit breaker. The fault current adaptive switching control system for the DC circuit breaker includes a DC circuit breaker and a controller, wherein the controller is configured to execute the fault current adaptive switching control method for the DC circuit breaker as described in any embodiment of the first aspect of this application.

[0017] Based on the same inventive concept, in a third aspect, embodiments of this application provide a fault current adaptive switching control device for a DC circuit breaker. The DC circuit breaker includes a current-carrying branch and an oscillating branch connected in parallel. The fault current adaptive switching control device for the DC circuit breaker includes: The first acquisition module is used to acquire fault current information of the current-carrying branch when a fault is detected. The first calculation module is used to calculate the derivative information of at least one order corresponding to the fault current information based on the fault current information. The first prediction module is used to predict the fault current of the current-carrying branch at the first preset time based on derivative information. The first control module is used to adjust the switching time of the oscillation branch based on the predicted fault current through an adaptive control algorithm, and to control the switching of the DC circuit breaker based on the switching time.

[0018] Fourthly, embodiments of this application provide a fault current adaptive switching control device for a DC circuit breaker, the fault current adaptive switching control device for the DC circuit breaker comprising: Processor and memory storing computer program instructions; When the processor executes the computer program instructions, it implements the fault current adaptive switching control method for DC circuit breakers provided in any of the embodiments of this application above.

[0019] Fifthly, embodiments of this application provide a computer storage medium storing computer program instructions, which, when executed by a processor, implement the fault current adaptive switching control method for a DC circuit breaker as provided in any of the embodiments of this application above.

[0020] Sixthly, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform the fault current adaptive switching control method for a DC circuit breaker provided in any of the embodiments of this application described above.

[0021] As described above, this application provides an adaptive switching control method for fault current in a DC circuit breaker. The DC circuit breaker includes a parallel current-carrying branch and an oscillating branch. The method acquires fault current information of the current-carrying branch when a fault is detected. Based on the fault current information, it calculates at least one derivative of the fault current information. Then, based on the derivative information, it predicts the fault current of the current-carrying branch at a first preset time. Finally, based on the predicted fault current, it adjusts the switching time of the oscillating branch using an adaptive control algorithm and performs switching control on the DC circuit breaker based on the switching time.

[0022] Compared to existing technologies that use fixed-time switching of the oscillating branch, this application's embodiment of an adaptive switching control method for DC circuit breakers based on fault current calculates at least one order of the derivative information of the fault current and predicts the fault current of the current-carrying branch at a first preset time based on the derivative information, enabling accurate prediction of the fault current's development trend in advance. Then, based on the predicted magnitude and characteristics of the fault current, the switching time of the oscillating branch is dynamically adjusted using an adaptive control algorithm, thereby adapting to current changes under different fault scenarios. This allows the DC circuit breaker to effectively and accurately achieve zero-crossing interruption when facing different fault currents. This embodiment of the application, by adaptively adjusting the switching time of the oscillating branch by predicting changes in the fault current, effectively improves the response timeliness and interruption reliability of the DC circuit breaker under various fault conditions, significantly enhancing the performance of the DC circuit breaker under rapidly changing fault conditions. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the fault current development curves at different switching times of a DC circuit breaker provided in an embodiment of this application; Figure 2 This is a flowchart illustrating an embodiment of the fault current adaptive switching control method for a DC circuit breaker provided in this application. Figure 3 This is a schematic diagram of the structure of a DC circuit breaker provided in one embodiment of this application; Figure 4 This is a schematic diagram of the fault current adaptive switching control system of a DC circuit breaker provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a fault current adaptive switching control device for a DC circuit breaker provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a fault current adaptive switching control device for a DC circuit breaker provided in an embodiment of this application. Detailed Implementation

[0025] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0027] As described in the background section, a hybrid oscillating DC circuit breaker typically includes a current-carrying branch and an oscillating branch connected in parallel. When a fault current occurs, the mechanical switch on the current-carrying branch trips, and the oscillating branch needs to be activated in conjunction with this. After activation, an increasing oscillating current is generated, which is superimposed on the main branch current to create a zero-crossing arc-extinguishing condition for the fast mechanical switch, thereby achieving zero-crossing interruption of the switching current on the current-carrying branch.

[0028] The inventors of this application have discovered that mechanical switches have a moment of initial opening. After the system issues a tripping command, a certain amount of time is required for the opening gap to acquire sufficient post-arc dielectric recovery capability, thus enabling successful interruption when the current crosses zero. The moment of current zero-crossing is closely related to the switching timing of the oscillation unit. Please refer to [link to relevant documentation]. Figure 1 , Figure 1 This is a schematic diagram showing the development of fault current at different switching times of a DC circuit breaker according to an embodiment of this application. For different fault current magnitudes, if the switching time of the oscillation unit remains constant, the following problems may occur: [Combined with...] Figure 1 As shown, if the switching time is too early, the mechanical switch may not have sufficient post-arc withstand voltage capability; if the switching time is too late, the turn-off time requirement may not be met, which may affect the fault isolation effect of the DC circuit breaker.

[0029] Therefore, due to the fixed switching time of the oscillating branch, the existing hybrid oscillating DC circuit breaker technology is difficult to achieve precise current zero-crossing interruption under different fault current conditions, and the interruption effect is limited, which restricts the application effect and reliability of DC circuit breakers in flexible DC transmission and large-scale renewable energy access scenarios.

[0030] In view of the above, in order to solve the problems of the prior art, this application provides an adaptive switching control method for fault current of a DC circuit breaker. It should be noted that the embodiments provided in this application are not intended to limit the scope of this application.

[0031] The following section first introduces the adaptive switching control method for fault current of DC circuit breakers provided in the embodiments of this application.

[0032] Figure 2 A flowchart illustrating an embodiment of the adaptive fault current switching control method for a DC circuit breaker provided in this application is shown. This adaptive fault current switching control method for a DC circuit breaker is applied at the system end, which can be, for example, electronic equipment such as a controller. Figure 2 As shown, the adaptive switching control method for fault current of the DC circuit breaker includes the following steps: S210: In the event of a detected fault, acquire the fault current information of the current-carrying branch; S220, based on the fault current information, calculate the derivative information of at least one order corresponding to the fault current information; S230, based on derivative information, predicts the predicted fault current of the current-carrying branch at the first preset time. S240 adjusts the switching time of the oscillation branch based on the predicted fault current through an adaptive control algorithm, and performs switching control of the DC circuit breaker based on the switching time.

[0033] As described above, this application provides an adaptive switching control method for fault current in a DC circuit breaker. The DC circuit breaker includes a parallel current-carrying branch and an oscillating branch. The method acquires fault current information of the current-carrying branch when a fault is detected. Based on the fault current information, it calculates at least one derivative of the fault current information. Then, based on the derivative information, it predicts the fault current of the current-carrying branch at a first preset time. Finally, based on the predicted fault current, it adjusts the switching time of the oscillating branch using an adaptive control algorithm and performs switching control on the DC circuit breaker based on the switching time.

[0034] Compared to existing technologies that use fixed-time switching of oscillating branches, this application's embodiment of an adaptive switching control method for DC circuit breakers based on fault current calculates at least one order of derivative information of the fault current and predicts the fault current of the current-carrying branch at a first preset time based on the derivative information, enabling accurate prediction of the fault current's development trend in advance. Then, based on the predicted magnitude and characteristics of the fault current, the switching time of the oscillating branch is dynamically adjusted using an adaptive control algorithm, thereby adapting to current changes under different fault scenarios. This allows the DC circuit breaker to effectively and accurately achieve zero-crossing interruption when facing different fault currents. This embodiment of the application, by adaptively adjusting the switching time of the oscillating branch by predicting changes in the fault current, effectively improves the response timeliness and interruption reliability of the DC circuit breaker under various fault conditions, significantly enhancing its performance under rapidly changing fault conditions. This helps meet the high requirements for rapid DC fault clearance in flexible DC transmission systems and large-scale renewable energy integration scenarios.

[0035] To facilitate understanding of the fault current adaptive switching control method for the DC circuit breaker described in this application, the DC circuit breaker in the embodiments of this application will be introduced first. Please refer to... Figure 3 , Figure 3 This is a schematic diagram of the topology of a DC circuit breaker 100 provided in one embodiment of this application. The DC circuit breaker 100 provided in this application is applicable to scenarios such as flexible DC transmission systems and large-scale renewable energy integration. In some examples, the DC circuit breaker 100 can be installed at the converter side outlet of the DC transmission system to achieve DC transmission fault protection.

[0036] Combination Figure 3 As shown, in this topology, the DC circuit breaker 100 includes a current-carrying branch 10 and an oscillating branch 20 connected in parallel. A mechanical switch K is installed on the current-carrying branch 10. During stable system operation, the mechanical switch K is turned on to handle the DC current flowing through the system under normal operating conditions. This mechanical switch K can be, for example, a vacuum circuit breaker or similar switch; no specific limitation is made here.

[0037] When a fault current occurs, the mechanical switch K on the current-carrying branch 10 is tripped, and the oscillation branch 20 needs to be activated. After the oscillation branch 20 is activated, it can generate an increasing oscillation current, which is superimposed on the main branch current (current-carrying branch 10) to create the zero-crossing arc-extinguishing condition for the fast mechanical switch K, so as to realize the zero-crossing interruption of the switching current on the current-carrying branch 10.

[0038] Optionally, according to some embodiments of this application, the above-mentioned oscillation branch 20 includes an oscillation capacitor L, an oscillation capacitor C, and an oscillation module, wherein the oscillation module includes a power electronic switch; The oscillation capacitor L, the oscillation capacitor C, and the oscillation module are connected in series, and the oscillation capacitor L and the oscillation capacitor C are arranged adjacent to each other.

[0039] In this embodiment, the oscillating capacitor L and the oscillating capacitor C are arranged adjacently to form an oscillation unit, thereby ensuring the reliable generation of the oscillation current. Specifically, the oscillation module can adopt a half-bridge sub-module structure, generally including a pre-charge capacitor and a power electronic switch. Through the cooperation of the oscillating capacitor L, the oscillating capacitor C, the pre-charge capacitor, and the power electronic switch, the oscillation current is opposite in direction to the fault current, achieving zero-crossing arc extinction of the mechanical switch K when the current amplitude is the same as the fault current.

[0040] The aforementioned power electronic switches, such as IGBTs (Insulated Gate Bipolar Transistors), IGCTs (Integrated Gate-Commutated Thyristors), or MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), which are fully controllable switching devices, are not strictly limited here.

[0041] Optionally, according to some embodiments of this application, the DC circuit breaker 100 further includes an energy dissipation branch 30, which is connected in parallel with the current-carrying branch 10; Among them, a metal oxide surge arrester (MOV) is installed on the energy-consuming branch 30.

[0042] In this embodiment, the energy dissipation branch 30 includes a metal-oxide-semiconductor (MOV). The main function of the energy dissipation branch 30 is to absorb residual energy during the breaking process of the DC circuit breaker 100 and limit possible overvoltages, thereby ensuring the safe operation of the entire device.

[0043] Specifically, after the mechanical switch K completes its breaking action, the fault current charges the oscillating capacitor C. As the charging process continues, the current gradually shifts to the energy-dissipating branch 30. At this time, the metal oxide surge arrester (MOV) begins to function, absorbing the remaining energy and effectively limiting any overvoltages that may occur during the breaking process.

[0044] In this way, the energy-consuming branch 30 ensures the smooth clearance of the fault current, ultimately enabling the DC circuit breaker 100 to successfully interrupt the fault current. This significantly improves the performance of the DC circuit breaker 100 under rapidly changing fault conditions and helps meet the high requirements for rapid clearance of DC faults in flexible DC transmission systems and large-scale renewable energy access scenarios.

[0045] Based on the DC circuit breaker provided in the above embodiments, the specific implementation methods of steps 210 to 240 are described in detail below. It should be noted that in some other embodiments, the DC circuit breaker in this application can also be implemented using other topologies, which are not strictly limited here.

[0046] In S210, when a fault is detected, the fault current information of the current-carrying branch is acquired.

[0047] In practice, the DC circuit breaker is equipped with a current sensor that can measure the current in real time and upload the current data to the system. If a fault is detected based on the measured current, fault current information is collected for a period of time (e.g., 3ms) for subsequent fault current prediction.

[0048] Optionally, according to some embodiments of this application, before acquiring the fault current information of the current-carrying branch in the event of a fault detection, the fault current adaptive switching control method of the DC circuit breaker further includes: The current information in the current-carrying branch is obtained by a current sensor, which is installed in the DC circuit breaker. The current information is compared with a preset current threshold, and a fault is determined to have occurred if the current information exceeds the preset current threshold.

[0049] The aforementioned current sensor is installed in the current-carrying branch of the DC circuit breaker, and can monitor the current flowing through the current-carrying branch in real time and report the collected current to the system.

[0050] The aforementioned preset current threshold is a reference value set based on the rated operating current of the DC circuit breaker and the system's definition of fault current, used to distinguish between normal operating current and fault current. By setting a reasonable threshold, it is possible to effectively differentiate between normal operating conditions and fault conditions.

[0051] Specifically, before a fault is detected, current information in the current-carrying branch needs to be obtained through a current sensor installed in the DC circuit breaker. The current sensor transmits the detected current signal to the system, providing data support for subsequent fault diagnosis and handling.

[0052] In this way, after acquiring the current information in the current-carrying branch, the current information is compared with a preset current threshold. When the current information exceeds the preset current threshold, a fault is determined to have occurred. Once a fault is determined, the subsequent fault handling process will be triggered to achieve adaptive switching control of the DC circuit breaker.

[0053] In S220, specifically, based on the fault current information, at least one order of derivative information corresponding to the fault current information is calculated using methods such as the finite difference method, analytical method, or numerical differentiation method. This at least one order of derivative information can be, for example, the first derivative, second derivative, third derivative, or at least a higher order derivative. For example, the first derivative reflects the instantaneous rate of change of the fault current, the second derivative further reveals the trend of the rate of change of the fault current, and higher order derivatives provide more detailed dynamic characteristic analysis. This derivative information of different orders provides a rich data foundation for subsequent fault current prediction and switching control.

[0054] It should be added that the derivative calculation method and order can be the same or different for fault current information collected at different time points, and no strict limitation is made here. In practical applications, the calculation method and order of the derivative can be flexibly selected according to the specific characteristics of the fault current and system requirements. For example, in some cases, it may be sufficient to calculate only the first derivative to meet the prediction accuracy requirements; while in other complex cases, it may be necessary to calculate derivatives of multiple orders simultaneously to more accurately capture the dynamic changes of the fault current.

[0055] Optionally, according to some embodiments of this application, based on the fault current information, the derivative information of at least one order corresponding to the fault current information is calculated, including: Based on the fault current information, calculate the first and / or second derivatives corresponding to the fault current information.

[0056] In this embodiment, the first derivative reflects the instantaneous rate of change of the fault current, i.e., the speed at which the current changes over time, and is an important indicator for assessing the development trend of the fault current. The second derivative further reveals the changing trend of the rate of change of the fault current, i.e., the acceleration of the current change, which helps to more accurately predict the future behavior of the fault current.

[0057] Therefore, by combining the first and / or second derivatives, the calculation is simple and efficient. While ensuring the accuracy of fault current prediction, the computational complexity is effectively controlled, ensuring the real-time performance and efficiency of the adaptive control algorithm. This avoids excessive computation and long processing time, enabling the DC circuit breaker to respond quickly under various fault conditions and achieve precise fault current interruption, thereby improving the safety and reliability of the entire power system.

[0058] In S230, specifically, based on derivative information, the predicted fault current of the current-carrying branch at the first preset time is predicted. This predicted fault current provides important data support for subsequent oscillation branch switching control, enabling the DC circuit breaker to achieve fast and reliable fault current interruption under various complex fault conditions, thereby effectively improving the safety and stability of the entire power system.

[0059] As an example, the aforementioned derivative information includes the first and / or second derivatives of the fault current, which reflect the changing trend and dynamic characteristics of the fault current. By utilizing this derivative information, a predictive model can be constructed to predict the value of the fault current at a predetermined future time. This predictive model can be built based on predictive methods such as linear regression models and neural networks; no strict limitations are imposed here.

[0060] It should be added that the aforementioned first preset time can be a fixed period of time after a fault is determined to have occurred. This fixed period of time is the maximum time within an acceptable range during which the system is allowed to complete the zero-crossing interruption of the mechanical switch after the fault is determined to have occurred. This can improve the safety and protection of the DC circuit breaker for the overall system.

[0061] Optionally, according to some embodiments of this application, predicting the fault current of a current-carrying branch at a preset time based on derivative information includes: Based on derivative information, the predicted fault current at a preset time is predicted through Taylor expansion or difference equations.

[0062] In this embodiment, to predict the fault current of the current-carrying branch at a preset time, a Taylor expansion or difference equation method is used for prediction based on the calculated derivative information. Both methods can effectively utilize derivative information to quickly and accurately predict the value of the fault current at a specific future time, providing data support for subsequent adaptive control.

[0063] In practical applications, for example, a prediction method based on Taylor expansion can be used to approximate the fault current value at future times by using Taylor series expansion based on the fault current and its derivative information at the current time.

[0064] For example, a prediction method based on difference equations can be used. Difference equations can be used to predict the value of the fault current at the first preset time based on the discrete data of the fault current and its derivative information.

[0065] In S240, based on the predicted fault current, the switching time of the oscillation branch is adjusted through an adaptive control algorithm, and the switching control of the DC circuit breaker is performed based on the switching time.

[0066] In practice, the adaptive control algorithm calculates the optimal switching time for the oscillating branch based on the predicted fault current value. This calculation process takes into account the breaking characteristics of the mechanical switch and the dynamic characteristics of the oscillating branch, ensuring reliable switching when the current crosses zero.

[0067] Thus, the adaptive control algorithm dynamically adjusts the switching timing of the oscillating branch. For example, if the predicted fault current indicates that the current zero-crossing time will be earlier, the algorithm will accordingly advance the switching timing of the oscillating branch; conversely, if the predicted fault current indicates that the current zero-crossing time will be delayed, the algorithm will accordingly delay the switching timing of the oscillating branch. This dynamic adjustment of the oscillating branch's switching timing ensures reliable interruption when the current in the current-carrying branch crosses zero.

[0068] Therefore, based on the predicted fault current, the switching time of the oscillation branch is adjusted through an adaptive control algorithm. The flexibility of the adaptive control algorithm enables the DC circuit breaker to better cope with complex and ever-changing fault scenarios.

[0069] Optionally, according to some embodiments of this application, a mechanical switch is included on the current-carrying branch; the fault current adaptive switching control method of the DC circuit breaker further includes: If a fault is detected, and the second preset time is reached, a trip command is sent to the DC circuit breaker so that the DC circuit breaker performs a trip operation on the mechanical switch. The second preset time is located before the first preset time, and the second preset time is located before the switching time of the oscillation branch.

[0070] Specifically, upon reaching the second preset time, the system sends a tripping command to the DC circuit breaker to trigger it to perform a tripping operation on the mechanical switch. The second preset time is prior to the first preset time and also prior to the switching time of the oscillation branch.

[0071] This ensures that the mechanical switch opening operation can be initiated at the appropriate stage of the fault current handling process, creating conditions for subsequent oscillation branch switching and fault current interruption. It avoids improper timing of oscillation branch switching due to mechanical switch opening delay, and further improves the reliability and accuracy of the entire fault current switching control process.

[0072] As an example, taking specific time parameters, assuming the fault occurrence time is 0 milliseconds, and the first preset time is set to 6 milliseconds for subsequent oscillation branch switching control, and the second preset time is set to 3 milliseconds, at which time a tripping command is sent to the DC circuit breaker, this timing arrangement facilitates a rapid response after a fault occurs. The mechanical switch tripping operation is initiated before the first preset time and the oscillation branch switching time, ensuring the continuity and effectiveness of the entire fault current switching control process.

[0073] Optionally, according to some embodiments of this application, the current in the current-carrying branch crosses zero at a target time, and the mechanical switch is used to complete the opening and closing at the target time; The target time is within a preset time range, the minimum time within the preset time range is after the switching time, and the maximum time within the preset time range is either at or before the first preset time.

[0074] In this embodiment, the current in the current-carrying branch of the DC circuit breaker crosses zero at a target time, and the mechanical switch is used to complete the breaking at the target time. The target time is set within a preset time range, which is defined based on the timing arrangement of the entire fault current switching control process and the characteristics of the mechanical switch.

[0075] Specifically, the minimum time within the preset time range is located after the switching time of the oscillating branch, while the maximum time within the preset time range is located at or before the first preset time. This time range setting ensures that the mechanical switch's opening action can be initiated at the appropriate time and the interruption is completed when the current crosses zero. As an example, the first preset time is, for example, 6 milliseconds, and the preset time range is, for example, 5.5 milliseconds to 6 milliseconds.

[0076] Optionally, according to some embodiments of this application, the time interval required for the mechanical switch to reach the target opening distance from the start of opening is a preset time interval, and the post-arc dielectric recovery capability of the mechanical switch at the target opening distance meets the preset conditions. The time interval between the second preset time and the minimum time within the preset time range is greater than or equal to the preset time interval.

[0077] In this embodiment, to ensure that the mechanical switch can reliably complete the opening and closing at the target time, the time interval required for the mechanical switch to reach the target opening distance from the start of opening is also considered, i.e., the preset time interval. The post-arc dielectric recovery capability of the mechanical switch at the target opening distance needs to meet the preset conditions to ensure successful opening when the current crosses zero.

[0078] In practical applications, the preset time interval is closely related to the actual operating conditions of the mechanical switch and the opening speed of the operating mechanism. For example, different mechanical switches may have different opening distance requirements (e.g., 8 mm, 10 mm, etc.), and the opening speed of the operating mechanism may also vary. Therefore, the time required to reach a certain opening distance depends on the operating conditions of the mechanical switch and the opening speed of the operating mechanism.

[0079] Based on this, by limiting the time interval between the second preset time and the minimum time within the preset time range to be greater than or equal to the preset time interval, it is ensured that the mechanical switch has enough time to reach the target opening distance from the start of opening and has sufficient post-arc dielectric recovery capability when the current crosses zero, thereby achieving reliable interruption.

[0080] As an example, the preset time interval is 2 milliseconds, and the preset time range can be set from 5.5 milliseconds to 6 milliseconds, with the minimum time within the preset time range being 5.5 milliseconds. This range is determined by taking into account the time required for the mechanical switch to reach the target opening distance from the start of opening, as well as the predicted time of current zero crossing.

[0081] Optionally, according to some embodiments of this application, switching control of the DC circuit breaker based on the switching time includes: Based on the switching timing of the oscillation branch, a switching control command is generated; Send a switching control command to the DC circuit breaker so that the DC circuit breaker controls the oscillation branch to be switched on when the switching time is reached.

[0082] In this embodiment, a corresponding switching control command is generated based on the switching time of the oscillation branch calculated by the adaptive control algorithm. This command contains specific time information for the oscillation branch to be activated, ensuring that the oscillation branch can be accurately activated at the preset switching time.

[0083] Next, after receiving the switching control command, the DC circuit breaker controls the oscillation branch to be engaged when the switching time is reached, so that the oscillation current on the oscillation branch is superimposed on the current of the branch where the mechanical switch is located, thereby enabling the DC circuit breaker to reliably complete the zero-crossing current interruption.

[0084] It should be noted that in some examples, the switching control command can be sent synchronously with the tripping command, and the DC circuit breaker may include a control module for controlling the switching. This control module, by receiving the switching control command and tripping command transmitted from the system, can control the tripping operation and the activation of the oscillation unit at appropriate times. Alternatively, in other embodiments, the system directly controls the tripping operation of the mechanical switch and the activation operation of the oscillation unit in the DC circuit breaker; this is not strictly limited.

[0085] Optionally, according to some embodiments of this application, after the mechanical switch is turned off at the moment the current crosses zero, the oscillation branch of the DC circuit breaker can be controlled to switch off, ensuring the reliable operation of the DC circuit breaker after fault handling.

[0086] Therefore, by promptly disconnecting the oscillation branch after the mechanical switch has been turned off, the DC circuit breaker can avoid unnecessary energy loss and system interference caused by the continuous operation of the oscillation branch. This not only improves the operating efficiency of the DC circuit breaker, but also enhances its adaptability and stability under complex fault conditions.

[0087] To facilitate understanding of the fault current adaptive switching control method for DC circuit breakers provided in the above embodiments, the following describes the method using a specific scenario embodiment.

[0088] The application scenario of this example is as follows: A DC circuit breaker is equipped with a current sensor, which can measure the current in real time and upload the current data to the system. When the fault current gradually increases, the system receives the uploaded current data and calculates the first and second derivatives of the current based on the current information of the branch where the mechanical switch is located. Using a method based on Taylor expansion or difference equations, the system predicts the fault current at 6ms (assuming the system issues a command to the DC circuit breaker in 3ms and requires a turn-off time of 3ms). Based on the prediction results, the switching time of the oscillation unit is dynamically adjusted through an adaptive control algorithm to ensure the accurate switching of the oscillation unit.

[0089] This scenario implementation example may specifically include the following processes: At 0ms: A fault is detected, and the fault current begins to rise. The current sensor inside the DC circuit breaker uploads the fault current information to the system in real time. Based on the uploaded fault current information, the system calculates the derivatives of the fault current information, such as the first and second derivatives, predicts the magnitude of the fault current at 6ms (corresponding to the aforementioned first preset time), and determines the switching time t1 of the oscillation unit through an adaptive control algorithm.

[0090] The 3ms timeframe corresponds to the second preset timeframe in the aforementioned embodiment. The system sends a tripping command to the DC circuit breaker and simultaneously sends the determined switching time t1 of the oscillation unit to the control module in the DC circuit breaker. Since the mechanical switch requires approximately 2ms to trip immediately, this 2ms corresponds to the preset time interval in the aforementioned embodiment. At least 2ms is needed after the mechanical switch begins tripping to allow sufficient post-arc dielectric recovery capability for the opening gap to complete the tripping action.

[0091] Time t1: Time t1 corresponds to the switching time in the aforementioned embodiment. The oscillation unit in the DC circuit breaker begins to engage, and the oscillation current is superimposed on the current in the branch where the mechanical switch is located.

[0092] Time t2 (5.5ms-6.0ms): Time t2 corresponds to the target time in the aforementioned embodiment. This target time is within a preset time range, such as 5.5ms-6.0ms. 6.0ms corresponds to the second preset time in the aforementioned embodiment. The current in the branch where the mechanical switch is located successfully crosses zero, completing the current interruption. The fault current begins to gradually decrease, and the DC circuit breaker successfully interrupts the current.

[0093] In this scenario embodiment, a fault current adaptive oscillation unit switching strategy is proposed. This strategy addresses the uncertainty of the preset zero-crossing time of the current by dynamically adjusting the switching time of the oscillation circuit. The system adaptively determines the switching time of the oscillation circuit by measuring the current in real time and predicting the magnitude of the fault current, thereby effectively improving the response timeliness and breaking reliability of the DC circuit breaker under various fault scenarios.

[0094] Based on the fault current adaptive switching control method for DC circuit breakers provided in the above embodiments, and with the same inventive concept, this application also provides a fault current adaptive switching control system for DC circuit breakers corresponding to the above-mentioned fault current adaptive switching control method. The following describes... Figure 4 This paper provides a detailed introduction to the fault current adaptive switching control system for DC circuit breakers.

[0095] like Figure 4 As shown, this application provides a fault current adaptive switching control system 1000 for a DC circuit breaker. The fault current adaptive switching control system 1000 for a DC circuit breaker includes a DC circuit breaker 100 and a controller 200. The controller 200 is configured to execute the fault current adaptive switching control method for a DC circuit breaker according to any of the foregoing embodiments of this application.

[0096] It should be understood that the examples of the DC circuit breaker 100 provided in the above embodiments of this application can be found in the foregoing. Figure 3And its corresponding descriptions, for the sake of brevity, will not be elaborated upon here.

[0097] Based on the fault current adaptive switching control method for DC circuit breakers provided in the above embodiments, and with the same inventive concept, this application also provides a fault current adaptive switching control device for DC circuit breakers corresponding to the above-mentioned fault current adaptive switching control method. The following describes... Figure 5 This paper provides a detailed introduction to the fault current adaptive switching control device for DC circuit breakers.

[0098] Figure 5 The diagram shows a schematic of the fault current adaptive switching control device for a DC circuit breaker provided in an embodiment of this application. The DC circuit breaker includes a current-carrying branch and an oscillation branch connected in parallel. Figure 5 The fault current adaptive switching control device 500 of the DC circuit breaker shown includes: The first acquisition module 510 is used to acquire fault current information of the current-carrying branch when a fault is detected. The first calculation module 520 is used to calculate the derivative information of at least one order corresponding to the fault current information based on the fault current information. The first prediction module 530 is used to predict the predicted fault current of the current-carrying branch at a first preset time based on derivative information. The first control module 540 is used to adjust the switching time of the oscillation branch based on the predicted fault current through an adaptive control algorithm, and to control the switching of the DC circuit breaker based on the switching time.

[0099] This application provides an adaptive fault current switching control device for a DC circuit breaker. By setting corresponding functional modules, it acquires fault current information of the current-carrying branch when a fault is detected. Based on the fault current information, it calculates at least one derivative of the fault current, and then predicts the fault current of the current-carrying branch at a first preset time based on the derivative information. Finally, based on the predicted fault current, it adjusts the switching time of the oscillating branch using an adaptive control algorithm, and performs switching control on the DC circuit breaker based on the switching time.

[0100] Compared to the existing control method that uses fixed-time switching of the oscillating branch, the fault current adaptive switching control device for a DC circuit breaker according to this application calculates the derivative information of at least one order of the fault current and predicts the fault current of the current-carrying branch at a first preset time based on the derivative information, thus accurately predicting the development trend of the fault current in advance. Then, based on the magnitude and characteristics of the predicted fault current, the switching time of the oscillating branch is dynamically adjusted through an adaptive control algorithm, thereby adapting to current changes under different fault scenarios. This allows the DC circuit breaker to effectively and accurately achieve zero-crossing interruption when facing different fault currents. This embodiment of the application adaptively adjusts the switching time of the oscillating branch according to changes in the fault current, effectively improving the response timeliness and interruption reliability of the DC circuit breaker under various fault conditions. It significantly enhances the performance of the DC circuit breaker under rapidly changing fault conditions, helping to meet the high requirements for rapid clearing of DC faults in flexible DC transmission systems and large-scale renewable energy access scenarios.

[0101] Optionally, according to some embodiments of this application, the first calculation module 520 calculates the derivative information of at least one order corresponding to the fault current information based on the fault current information, including: Based on the fault current information, calculate the first and / or second derivatives corresponding to the fault current information.

[0102] Optionally, according to some embodiments of this application, the first prediction module 530 predicts the predicted fault current of the current-carrying branch at a preset time based on derivative information, including: Based on derivative information, the predicted fault current at a preset time is predicted through Taylor expansion or difference equations.

[0103] Optionally, according to some embodiments of this application, a mechanical switch is included on the current-carrying branch; the fault current adaptive switching control device of the DC circuit breaker further includes: The first transmitting module is used to send a tripping command to the DC circuit breaker when a fault is detected and a second preset time is reached, so that the DC circuit breaker performs a tripping operation on the mechanical switch. The second preset time is located before the first preset time, and the second preset time is located before the switching time of the oscillation branch.

[0104] Optionally, according to some embodiments of this application, the current in the current-carrying branch crosses zero at a target time, and the mechanical switch is used to complete the opening and closing at the target time; The target time is within a preset time range, the minimum time within the preset time range is after the switching time, and the maximum time within the preset time range is either at or before the first preset time.

[0105] Optionally, according to some embodiments of this application, the time interval required for the mechanical switch to reach the target opening distance from the start of opening is a preset time interval, and the post-arc dielectric recovery capability of the mechanical switch at the target opening distance meets the preset conditions. The time interval between the second preset time and the minimum time within the preset time range is greater than or equal to the preset time interval.

[0106] Optionally, according to some embodiments of this application, switching control of the DC circuit breaker based on the switching time includes: Based on the switching timing of the oscillation branch, a switching control command is generated; Send a switching control command to the DC circuit breaker so that the DC circuit breaker controls the oscillation branch to be switched on when the switching time is reached.

[0107] Optionally, according to some embodiments of this application, before acquiring the fault current information of the current-carrying branch in the event of a detected fault, the fault current adaptive switching control device of the DC circuit breaker further includes: The second acquisition module is used to acquire current information in the current-carrying branch through a current sensor, which is installed in the DC circuit breaker. The fault determination module is used to compare the current information with a preset current threshold, and determine that a fault has occurred if the current information exceeds the preset current threshold.

[0108] Optionally, according to some embodiments of this application, the oscillation branch includes an oscillation inductor, an oscillation capacitor, and an oscillation module, wherein the oscillation module includes a power electronic switch; The oscillating inductor, oscillating capacitor, and oscillating module are connected in series, and the oscillating inductor and oscillating capacitor are arranged adjacent to each other.

[0109] Optionally, according to some embodiments of this application, the DC circuit breaker further includes an energy-dissipating branch, which is connected in parallel with the current-carrying branch; Metal oxide surge arresters are installed on the energy-consuming branches.

[0110] Based on the fault current adaptive switching control method for DC circuit breakers provided in the above embodiments, and with the same inventive concept, this application also provides a fault current adaptive switching control device for DC circuit breakers corresponding to the above-mentioned fault current adaptive switching control method. The following describes... Figure 6 This paper provides a detailed introduction to the fault current adaptive switching control equipment for DC circuit breakers.

[0111] Please see below. Figure 6 , Figure 6 This is a schematic diagram of the structure of a fault current adaptive switching control device for a DC circuit breaker provided in an embodiment of this application.

[0112] The fault current adaptive switching control device for a DC circuit breaker may include a processor 601 and a memory 602 storing computer program instructions.

[0113] Specifically, the processor 601 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0114] Memory 602 may include mass storage for data or instructions. For example, and not limitingly, memory 602 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 602 may include removable or non-removable (or fixed) media. Where appropriate, memory 602 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 602 is non-volatile solid-state memory.

[0115] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the methods according to one aspect of this disclosure.

[0116] The processor 601 reads and executes computer program instructions stored in the memory 602 to implement any of the fault current adaptive switching control methods for DC circuit breakers in the above embodiments.

[0117] In one example, the fault current adaptive switching control device for the data DC circuit breaker may further include a communication interface 603 and a bus 610. Wherein, as Figure 6 As shown, the processor 601, memory 602, and communication interface 603 are connected through bus 610 and complete communication with each other.

[0118] The communication interface 603 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0119] Bus 610 includes hardware, software, or both, that couples components of a DC circuit breaker's fault current adaptive switching control device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 610 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0120] The fault current adaptive switching control device of the DC circuit breaker executes the fault current adaptive switching control method of the DC circuit breaker in the embodiments of this application, thereby realizing the fault current adaptive switching control method of the DC circuit breaker described in the embodiments of this application.

[0121] Furthermore, in conjunction with the adaptive switching control method for fault current of the DC circuit breaker in the above embodiments, this application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the adaptive switching control methods for fault current of the DC circuit breaker in the above embodiments.

[0122] Based on the fault current adaptive switching control method for DC circuit breakers in the above embodiments, this application provides a computer program product. When the instructions in the computer program product are executed by the processor of an electronic device, the electronic device performs the fault current adaptive switching control method for DC circuit breakers provided in any of the above embodiments of this application.

[0123] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0124] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0125] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0126] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0127] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A fault current adaptive switching control method for a DC circuit breaker, characterized in that, The DC circuit breaker includes a current-carrying branch and an oscillating branch connected in parallel, and the method includes: If a fault is detected, the fault current information of the current-carrying branch is obtained; Based on the fault current information, calculate the derivative information of at least one order corresponding to the fault current information; Based on the derivative information, the predicted fault current of the current-carrying branch at the first preset time is predicted; Based on the predicted fault current, the switching time of the oscillation branch is adjusted by an adaptive control algorithm, and the switching control of the DC circuit breaker is performed based on the switching time.

2. The method according to claim 1, characterized in that, The step of calculating the derivative information of at least one order corresponding to the fault current information based on the fault current information includes: Based on the fault current information, calculate the first and / or second derivatives corresponding to the fault current information.

3. The method according to claim 1, characterized in that, The step of predicting the predicted fault current of the current-carrying branch at a preset time based on the derivative information includes: Based on the derivative information, the predicted fault current at the preset time is predicted by Taylor expansion or difference equation.

4. The method according to claim 1, characterized in that, The current-carrying branch includes a mechanical switch; the method further includes: If a fault is detected, and a second preset time is reached, a tripping command is sent to the DC circuit breaker to cause the DC circuit breaker to perform a tripping operation on the mechanical switch. Wherein, the second preset time is located before the first preset time, and the second preset time is located before the switching time of the oscillation branch.

5. The method according to claim 4, characterized in that, The current in the current-carrying branch crosses zero at the target time, and the mechanical switch is used to complete the opening and closing at the target time; The target time is within a preset time range, the minimum time within the preset time range is after the switching time, and the maximum time within the preset time range is either at or before the first preset time.

6. The method according to claim 5, characterized in that, The time interval required for the mechanical switch to reach the target opening distance from the start of opening is a preset time interval, and the post-arc dielectric recovery capability of the mechanical switch at the target opening distance meets the preset conditions. The time interval between the second preset time and the minimum time within the preset time range is greater than or equal to the preset time interval.

7. The method according to claim 1, characterized in that, The switching control of the DC circuit breaker based on the switching time includes: Based on the switching time of the oscillation branch, a switching control command is generated; The switching control command is sent to the DC circuit breaker so that the DC circuit breaker controls the oscillation branch to be switched on when the switching time is reached.

8. The method according to claim 1, characterized in that, Before acquiring the fault current information of the current-carrying branch upon detecting a fault, the method further includes: The current information in the current-carrying branch is obtained by a current sensor, which is installed in the DC circuit breaker. The current information is compared with a preset current threshold, and a fault is determined to have occurred if the current information exceeds the preset current threshold.

9. The method according to claim 1, characterized in that, The oscillation branch includes an oscillation inductor, an oscillation capacitor, and an oscillation module, wherein the oscillation module includes a power electronic switch; The oscillating inductor, the oscillating capacitor, and the oscillation module are connected in series, and the oscillating inductor and the oscillating capacitor are arranged adjacent to each other.

10. The method according to claim 1, characterized in that, The DC circuit breaker also includes an energy-dissipating branch, which is connected in parallel with the current-carrying branch; Metal oxide surge arresters are installed on the energy-consuming branch.

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