A high-voltage direct current transmission line traveling wave protection method, system, device and medium

Abstract

The application discloses a high-voltage direct-current transmission line traveling wave protection method, system, device and medium, and the method comprises the following steps: acquiring a transient voltage of a direct-current line; determining whether the protection is started according to the transient voltage and a preset starting criterion, if yes, the protection is started, and the transient voltage traveling wave of the direct-current line is acquired; performing multi-scale wavelet transform on the transient voltage traveling wave to extract feature information; determining the fault type and whether the protection is operated according to whether the feature information meets a preset action criterion and an auxiliary criterion, if yes, the protection is operated, and the direct-current circuit breaker is tripped; controlling the direct-current circuit breaker to reclose through a preset reclosing strategy, and determining whether the reclosing is successful, if no, the fault distance is determined, and the fault type and the fault distance are reported; and the application can reduce signal noise interference, accurately identify the fault type and the fault distance, and perform the protection operation through the direct-current circuit breaker, so that the safe and reliable operation of the direct-current transmission line is ensured.

Description

Technical Field

[0001] This invention relates to a traveling wave protection method, system, device, and medium for high voltage direct current transmission lines, belonging to the field of power transmission grid technology. Background Technology

[0002] With the development of renewable energy generation technologies, more and more wind and solar power are being integrated into the power system. Since renewable energy sources such as wind and solar are generally located in relatively remote areas, the AC networks in these areas may be inadequate, limiting power transmission. The development of converter station technology and high-voltage direct current (HVDC) transmission network technology has led to increasing attention being paid to the field of DC transmission. Multiterminal High-Voltage Direct Current (MT-HVDC) transmission systems can effectively integrate renewable energy sources and have advantages such as high communication accuracy and low energy loss, making them a major development trend. A major challenge for MT-HVDC transmission systems is the detection and elimination of DC faults, a technology crucial to the reliability and stability of the MT-HVDC system. Current fault detection and elimination schemes are either too sensitive to load changes, making them susceptible to signal noise interference in practical applications, leading to false alarms; or their signal detection and response speeds are too slow to detect faults before equipment failure. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a traveling wave protection method, system, device and medium for high voltage direct current transmission lines, which can reduce interference caused by signal noise, accurately identify the fault type and fault distance, and perform protection actions through DC circuit breakers to ensure the safe and reliable operation of DC transmission lines.

[0004] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0005] In a first aspect, the present invention provides a traveling wave protection method for high-voltage direct current transmission lines, comprising:

[0006] Obtain the transient voltage of the DC line;

[0007] The protection system determines whether to start based on whether the transient voltage meets the preset start criteria. If the start criteria are met, the protection starts and acquires the transient voltage traveling wave of the DC line; if the start criteria are not met, the protection does not start.

[0008] Multi-scale wavelet transform is performed on transient voltage traveling waves to extract wavelet energy values ​​of high-frequency and low-frequency components of transient voltage.

[0009] Based on whether the wavelet energy values ​​of the high-frequency and low-frequency components of the transient voltage meet the preset action criteria and auxiliary criteria, the fault type and whether the protection should operate are determined. If yes, the protection operates and controls the DC circuit breaker to trip; if no, the protection does not operate.

[0010] The DC circuit breaker is controlled to reclose using a preset reclosing strategy. If the reclosing is successful, the protection is completed. If not, the fault distance is determined based on the fault type and transient voltage traveling wave, and the fault type and fault distance are reported.

[0011] Optionally, the activation criterion is:

[0012] |VV s |>kV s

[0013] In the formula, V, V s Here, represents the transient and steady-state voltages of the DC line, and k is the setting threshold coefficient.

[0014] Optionally, the action criterion is:

[0015] E H (n)>E H,th

[0016] In the formula, E H (n) represents the wavelet energy value of the high-frequency component of the transient voltage, E H,th The high-frequency component wavelet energy threshold is the set value.

[0017] Optionally, the auxiliary criterion is:

[0018] E L (n)>E L,th

[0019] In the formula, E L (n) represents the wavelet energy value of the low-frequency component of the transient voltage, E L,th The low-frequency component wavelet energy threshold is the value to be tuned.

[0020] Optionally, determining the fault type includes:

[0021] If the preset action criteria are met, the fault type is an intra-zone fault of the DC line.

[0022] If the preset action criteria are not met, the fault type is an external fault of the DC line.

[0023] If the preset auxiliary criteria are met, the fault type is lightning strike fault;

[0024] If the preset auxiliary criteria are not met, the fault type is a non-lightning strike fault.

[0025] Optionally, determining whether the protection is activated includes:

[0026] The protection system determines whether to operate based on the wavelet energy value of the high-frequency component of the transient voltage and whether the preset operating criteria are met. If the operating criteria are not met, the protection does not operate. If the operating criteria are met, the protection system determines whether to operate based on the wavelet energy value of the low-frequency component of the transient voltage and whether the preset auxiliary criteria are met. If the auxiliary criteria are not met, the protection does not operate. If the auxiliary criteria are met, the protection operates.

[0027] Optionally, controlling the reclosing of the DC circuit breaker through a preset reclosing strategy includes:

[0028] When the DC circuit breaker trips for a preset first duration, the DC circuit breaker is controlled to reclose for the first time.

[0029] Within a preset second time period after the first reclosing, the transient voltage of the DC line is acquired, and it is determined whether the transient voltage rises to 0.95pu. If so, the reclosing is successful; otherwise, the DC circuit breaker is controlled to trip.

[0030] When the DC circuit breaker trips for a preset first time period, control the DC circuit breaker to reclose for the second time.

[0031] Within a preset second time period after the second reclosing, the transient voltage of the DC line is acquired, and it is determined whether the transient voltage rises to 0.96 pu. If so, the reclosing is successful; otherwise, the reclosing fails, and the DC circuit breaker is controlled to trip.

[0032] In this embodiment, the first and second durations are both preset to 200ms, and pu is a per-unit value, which can be the steady-state voltage of the DC line.

[0033] Optionally, determining the fault distance based on the fault type and transient voltage traveling wave includes:

[0034] Based on the action criteria and auxiliary criteria, the fault type is determined to be an intra-area fault of the DC line, and it is a lightning strike fault;

[0035] Based on the arrival time of the transient voltage traveling wave, the location of the fault within the DC line area is obtained, and the fault distance is calculated based on the location.

[0036] Secondly, the present invention provides a traveling wave protection system for high-voltage direct current transmission lines, the system comprising:

[0037] Voltage acquisition module, used to acquire transient voltage of DC line;

[0038] The protection start-up module is used to determine whether the protection should be started based on whether the transient voltage meets the preset start-up criteria. If the start-up criteria are met, the protection is started and the transient voltage traveling wave of the DC line is acquired; if the start-up criteria are not met, the protection is not started.

[0039] The wavelet transform module is used to perform multi-scale wavelet transform on transient voltage traveling waves to extract wavelet energy values ​​of high-frequency and low-frequency components of transient voltage.

[0040] The protection action module is used to determine the fault type and whether the protection should be activated based on whether the wavelet energy values ​​of the high-frequency and low-frequency components of the transient voltage meet the preset action criteria and auxiliary criteria. If so, the protection is activated and the DC circuit breaker is tripped.

[0041] The reclosing module is used to control the reclosing of the DC circuit breaker through a preset reclosing strategy and to determine whether the reclosing is successful. If it is successful, the protection is completed; if not, the fault distance is determined according to the fault type and transient voltage traveling wave, and the fault type and fault distance are reported.

[0042] Thirdly, the present invention provides a traveling wave protection device for high voltage direct current transmission lines, including a processor and a storage medium;

[0043] The storage medium is used to store instructions;

[0044] The processor is used to perform the steps of the above method according to the instructions.

[0045] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0046] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0047] This invention provides a traveling wave protection method, system, device, and medium for high-voltage direct current (HVDC) transmission lines. It uses a start-up criterion for protection initiation, and employs multi-scale wavelet transform to reduce interference from signal noise, improving the accuracy and speed of fault detection in HVDC transmission lines. Combined with action criteria and auxiliary criteria, it can accurately identify the fault type and fault distance. By tripping the HVDC circuit breaker, the fault can be promptly cleared, and after clearing, a reclosing strategy is used to attempt reclosing, thereby ensuring the safe and reliable operation of the HVDC transmission line. Attached Figure Description

[0048] Figure 1 This is a flowchart of a traveling wave protection method for high-voltage direct current transmission lines provided in Embodiment 1 of the present invention;

[0049] Figure 2This is a flowchart of controlling the reclosing of a DC circuit breaker through a preset reclosing strategy, provided in Embodiment 1 of the present invention.

[0050] Figure 3 This is a schematic diagram of the architecture of the MT-HVDC power transmission system provided in Embodiment 1 of the present invention;

[0051] Figure 4 This is a basic circuit structure diagram of the hybrid high-voltage DC circuit breaker provided in Embodiment 1 of the present invention. Detailed Implementation

[0052] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0053] Example 1:

[0054] like Figure 1 As shown, the present invention provides a traveling wave protection method for high-voltage direct current transmission lines, comprising the following steps:

[0055] 1. Obtain the transient voltage of the DC line.

[0056] 2. Determine whether the protection should start based on whether the preset start criterion is met by judging the transient voltage. If the start criterion is met, the protection starts and the transient voltage traveling wave of the DC line is obtained; if the start criterion is not met, the protection does not start.

[0057] The triggering criterion is:

[0058] |VV s |>kV s

[0059] In the formula, V, V s Here, represents the transient and steady-state voltages of the DC line, and k is the setting threshold coefficient.

[0060] 3. Perform multi-scale wavelet transform on the transient voltage traveling wave to extract the wavelet energy values ​​of the high-frequency and low-frequency components of the transient voltage.

[0061] Multiscale wavelet transform is achieved through discrete wavelet decomposition. Its fast decomposition is based on the Mallat algorithm and employs multiscale wavelet decomposition. By increasing the scale of wavelet decomposition, the influence of signal noise is reduced.

[0062] Wavelet transform can quickly and accurately detect fault signals in power systems, such as sudden changes in voltage and current signals. For the signal input function x(t), its continuous wavelet transform is given by the following equation:

[0063]

[0064] In the formula, * represents the complex conjugate, parameter a is the scaling parameter, parameter b is the translation parameter, and t is the time-space variable. If there exists a t0 such that the modulus of the wavelet transform is a local maximum in its neighborhood, then t0 indicates that the signal undergoes a sudden change. By identifying the modulus maxima of the wavelet transform, fault information in the power system can be determined, the sudden change point of the fault signal can be obtained, and the wavefront of the traveling wave can be distinguished from noise.

[0065] The fast decomposition of discrete wavelets is based on the Mallat algorithm. For a discrete sequence x(n), the Mallat algorithm decomposition formula is as follows:

[0066]

[0067] In the formula, h(n) and g(n) represent the low-pass and high-pass filters corresponding to the selected wavelet functions, respectively, and k is the sequence variable. Wavelet discretization is performed on the transient voltage traveling wave component over a period of time, and the magnitudes of its high-frequency and low-frequency components are denoted as W0 and W0, respectively. L (n) and W H (n), wavelet energy E L (n) and E H (n) are respectively:

[0068] E L (n)=|W L (n)| 2

[0069] E H (n)=|W H (n)| 2

[0070] 4. Determine the fault type and whether the protection should operate based on whether the wavelet energy values ​​of the high-frequency and low-frequency components of the transient voltage meet the preset action criteria and auxiliary criteria. If so, the protection should operate and control the DC circuit breaker to trip.

[0071] 4.1 The action criterion is:

[0072] E H (n)>E H,th

[0073] In the formula, E H (n) represents the wavelet energy value of the high-frequency component of the transient voltage, E H,th The high-frequency component wavelet energy threshold is the set value.

[0074] 4.2. The auxiliary criterion is:

[0075] E L (n)>E L,th

[0076] In the formula, E L(n) represents the wavelet energy value of the low-frequency component of the transient voltage, E L,th The low-frequency component wavelet energy threshold is the value to be tuned.

[0077] 4.3 Determining the fault type includes:

[0078] If the preset action criteria are met, the fault type is an intra-zone fault of the DC line.

[0079] If the preset action criteria are not met, the fault type is an external fault of the DC line.

[0080] If the preset auxiliary criteria are met, the fault type is lightning strike fault;

[0081] If the preset auxiliary criteria are not met, the fault type is a non-lightning strike fault.

[0082] 4.4 Determining whether the protection system has activated includes:

[0083] The protection system determines whether to operate based on the wavelet energy value of the high-frequency component of the transient voltage and whether the preset operating criteria are met. If the operating criteria are not met, the protection does not operate. If the operating criteria are met, the protection system determines whether to operate based on the wavelet energy value of the low-frequency component of the transient voltage and whether the preset auxiliary criteria are met. If the auxiliary criteria are not met, the protection does not operate. If the auxiliary criteria are met, the protection operates.

[0084] 5. Control the reclosing of the DC circuit breaker through the preset reclosing strategy, and determine whether the reclosing is successful. If it is, the protection is completed; if not, determine the fault distance according to the fault type and transient voltage traveling wave, and report the fault type and fault distance.

[0085] like Figure 2 As shown in Figure 5.1, controlling the reclosing of a DC circuit breaker through a preset reclosing strategy includes:

[0086] When the DC circuit breaker trips for a preset first duration, the DC circuit breaker is controlled to reclose for the first time.

[0087] Within a preset second time period after the first reclosing, the transient voltage of the DC line is acquired, and it is determined whether the transient voltage rises to 0.95pu. If so, the reclosing is successful; otherwise, the DC circuit breaker is controlled to trip.

[0088] When the DC circuit breaker trips for a preset first time period, control the DC circuit breaker to reclose for the second time.

[0089] Within a preset second time period after the second reclosing, the transient voltage of the DC line is acquired, and it is determined whether the transient voltage rises to 0.96pu. If so, the reclosing is successful; otherwise, the reclosing fails, and the DC circuit breaker is tripped.

[0090] 5.2 Determining the fault distance based on the fault type and transient voltage traveling wave includes:

[0091] Based on the satisfying action criteria and auxiliary criteria, the fault type is determined to be an intra-area fault of the DC line, and it is a lightning strike fault;

[0092] Based on the arrival time of the transient voltage traveling wave, the location of the fault within the DC line area is obtained, and the fault distance is calculated based on the location.

[0093] like Figure 3 The diagram shows the architecture of an MT-HVDC transmission system. In this system, AC nodes (AC generators) are connected to the DC grid on the DC side via converter stations. Unlike point-to-point systems, each AC node has only one converter station. To ensure safe and reliable system operation, high-speed DC circuit breakers are installed on both sides of the high-voltage DC line. The DC circuit breakers are controlled using the traveling wave protection method for high-voltage DC transmission lines provided in this embodiment, thereby detecting and eliminating DC faults.

[0094] The DC circuit breaker used in this embodiment is a high-speed DC circuit breaker, which is crucial for ensuring the safety and stability of the high-voltage DC power grid. To ensure that the protection device can quickly and reliably disconnect the fault after detection, the DC circuit breaker needs to meet the following requirements:

[0095] (1) Fast interruption speed.

[0096] (2) It can withstand large instantaneous interruption voltage of DC circuit.

[0097] (3) After the faulty circuit is disconnected, the energy stored in the circuit inductance can be quickly depleted.

[0098] (4) The DC circuit can be safely and reliably disconnected by artificially creating a current zero-crossing point.

[0099] Compared to mechanical and solid-state high-voltage DC circuit breakers, hybrid high-voltage DC circuit breakers combine the advantages of both and better meet the above requirements. The basic circuit structure of a hybrid high-voltage DC circuit breaker is as follows: Figure 4 As shown, its internal branches include current-carrying branches, current transfer branches, and energy absorption branches. Among them, the current-carrying branches are the main branches, with fast mechanical switches and a small number of power electronic modules, carrying the rated current of the circuit; the current transfer branches have a large number of power electronic modules connected in series. When the mechanical switch on the current-carrying branch is opened, the current is transferred to this branch, and the DC current is interrupted by the turn-off power electronic modules; the energy absorption branches have a large number of MOV valves connected in series and parallel, which can absorb energy and limit the transient breaking voltage generated during the DC circuit breaker's breaking process.

[0100] Example 2:

[0101] This invention provides a traveling wave protection system for high-voltage direct current transmission lines, the system comprising:

[0102] Voltage acquisition module, used to acquire transient voltage of DC line;

[0103] The protection start-up module is used to determine whether the protection should be started based on whether the transient voltage meets the preset start-up criteria. If the start-up criteria are met, the protection is started and the transient voltage traveling wave of the DC line is acquired; if the start-up criteria are not met, the protection is not started.

[0104] The wavelet transform module is used to perform multi-scale wavelet transform on transient voltage traveling waves to extract wavelet energy values ​​of high-frequency and low-frequency components of transient voltage.

[0105] The protection action module is used to determine the fault type and whether the protection should be activated based on whether the wavelet energy values ​​of the high-frequency and low-frequency components of the transient voltage meet the preset action criteria and auxiliary criteria. If so, the protection is activated and the DC circuit breaker is tripped.

[0106] The reclosing module is used to control the reclosing of the DC circuit breaker through a preset reclosing strategy and to determine whether the reclosing is successful. If it is successful, the protection is completed; if not, the fault distance is determined according to the fault type and transient voltage traveling wave, and the fault type and fault distance are reported.

[0107] Example 3:

[0108] Based on Embodiment 1, this embodiment of the invention provides a traveling wave protection device for high voltage direct current transmission lines, including a processor and a storage medium;

[0109] Storage media are used to store instructions;

[0110] The processor is used to perform the steps of the above method according to instructions.

[0111] Example 4:

[0112] Based on Embodiment 4, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0113] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0114] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of 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, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0115] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0116] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0117] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A traveling wave protection method for high-voltage direct current transmission lines, characterized in that, include: Obtain the transient voltage of the DC line; The protection is activated based on whether the preset start criteria are met by judging the transient voltage. If the start criteria are met, the protection is activated and the transient voltage traveling wave of the DC line is obtained. If the startup criteria are not met, then the system will not start. Multi-scale wavelet transform is performed on transient voltage traveling waves to extract wavelet energy values ​​of high-frequency and low-frequency components of transient voltage. Based on whether the wavelet energy values ​​of the high-frequency and low-frequency components of the transient voltage meet the preset action criteria and auxiliary criteria, the fault type and whether the protection should operate are determined. If yes, the protection operates and controls the DC circuit breaker to trip; if no, the protection does not operate. The DC circuit breaker is controlled to reclose using a preset reclosing strategy, and the success of the reclosing is determined. If the reclosing is successful, the protection is completed; otherwise, the fault distance is determined based on the fault type and transient voltage traveling wave, and the fault type and fault distance are reported. The method of controlling the reclosing of the DC circuit breaker through a preset reclosing strategy includes: When the DC circuit breaker trips for a preset first duration, the DC circuit breaker is controlled to reclose for the first time. Within a preset second time period after the first reclosing, the transient voltage of the DC line is acquired, and it is determined whether the transient voltage rises to 0.95pu. If so, the reclosing is successful; otherwise, the DC circuit breaker is controlled to trip. When the DC circuit breaker trips for a preset first time period, control the DC circuit breaker to reclose for the second time. Within a preset second time period after the second reclosing, the transient voltage of the DC line is acquired, and it is determined whether the transient voltage rises to 0.96 pu. If so, the reclosing is successful; otherwise, the reclosing fails, and the DC circuit breaker is controlled to trip.

2. The method for traveling wave protection of high-voltage direct current transmission lines according to claim 1, characterized in that, The activation criterion is: In the formula, These are the transient and steady-state voltages of a DC line. This is the threshold coefficient for setting.

3. The traveling wave protection method for high-voltage direct current transmission lines according to claim 1, characterized in that, The action criterion is: In the formula, The wavelet energy value of the high-frequency component of the transient voltage. The high-frequency component wavelet energy threshold is set.

4. The traveling wave protection method for high-voltage direct current transmission lines according to claim 1, characterized in that, The auxiliary criterion is: In the formula, This represents the wavelet energy value of the low-frequency component of the transient voltage. The low-frequency component wavelet energy threshold is the value to be tuned.

5. A traveling wave protection method for high-voltage direct current transmission lines according to claim 1, characterized in that, The determination of the fault type includes: If the preset action criteria are met, the fault type is an intra-zone fault of the DC line. If the preset action criteria are not met, the fault type is an external fault of the DC line. If the preset auxiliary criteria are met, the fault type is lightning strike fault; If the preset auxiliary criteria are not met, the fault type is a non-lightning strike fault.

6. The traveling wave protection method for high-voltage direct current transmission lines according to claim 1, characterized in that, Determining whether the protection is activated includes: The protection system determines whether to operate based on the wavelet energy value of the high-frequency component of the transient voltage and whether the preset operating criteria are met. If the operating criteria are not met, the protection does not operate. If the operating criteria are met, the protection system determines whether to operate based on the wavelet energy value of the low-frequency component of the transient voltage and whether the preset auxiliary criteria are met. If the auxiliary criteria are not met, the protection does not operate. If the auxiliary criteria are met, the protection operates.

7. A traveling wave protection method for high-voltage direct current transmission lines according to claim 1, characterized in that, The method of determining the fault distance based on the fault type and transient voltage traveling wave includes: Based on the action criteria and auxiliary criteria, the fault type is determined to be an intra-area fault of the DC line, and it is a lightning strike fault; Based on the arrival time of the transient voltage traveling wave, the location of the fault within the DC line area is obtained, and the fault distance is calculated based on the location.

8. A traveling wave protection system for high-voltage direct current transmission lines, characterized in that, The system includes: Voltage acquisition module, used to acquire transient voltage of DC line; The protection start-up module is used to determine whether the protection should be started based on whether the transient voltage meets the preset start-up criteria. If the start-up criteria are met, the protection is started and the transient voltage traveling wave of the DC line is acquired; if the start-up criteria are not met, the protection is not started. The wavelet transform module is used to perform multi-scale wavelet transform on transient voltage traveling waves to extract wavelet energy values ​​of high-frequency and low-frequency components of transient voltage. The protection action module is used to determine the fault type and whether the protection should be activated based on whether the wavelet energy values ​​of the high-frequency and low-frequency components of the transient voltage meet the preset action criteria and auxiliary criteria. If so, the protection is activated and the DC circuit breaker is tripped. The reclosing module is used to control the reclosing of the DC circuit breaker according to a preset reclosing strategy, and to determine whether the reclosing is successful. If successful, the protection is completed; if not, the fault distance is determined based on the fault type and transient voltage traveling wave, and the fault type and fault distance are reported. The preset reclosing strategy for controlling the reclosing of the DC circuit breaker includes: When the DC circuit breaker trips for a preset first duration, the DC circuit breaker is controlled to reclose for the first time. Within a preset second time period after the first reclosing, the transient voltage of the DC line is acquired, and it is determined whether the transient voltage rises to 0.95pu. If so, the reclosing is successful; otherwise, the DC circuit breaker is controlled to trip. When the DC circuit breaker trips for a preset first time period, control the DC circuit breaker to reclose for the second time. Within a preset second time period after the second reclosing, the transient voltage of the DC line is acquired, and it is determined whether the transient voltage rises to 0.96 pu. If so, the reclosing is successful; otherwise, the reclosing fails, and the DC circuit breaker is controlled to trip.

9. A traveling wave protection device for high-voltage direct current transmission lines, characterized in that, Including processor and storage media; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1-7.

Images