Electric power differential protection method based on Beidou wide area time service

Abstract

The invention relates to an electric power differential protection method based on Beidou wide-area time service, and the method comprises the following steps: collecting current and voltage data at two ends of a power transmission line in an electric power system, carrying out the time synchronization of the current and voltage data through a Beidou wide-area time service signal, and carrying out the preprocessing of the current and voltage data after the time synchronization; differential current and braking current of the power transmission line are calculated through a self-adaptive differential current calculation algorithm based on the current and voltage data at the two ends of the power transmission line; when the differential current of the power transmission line exceeds a preset threshold value, a tripping instruction is sent to a circuit breaker, and the fault power transmission line is isolated through the circuit breaker; and recording the power data of the power transmission line before and after the fault, compressing and marking the circuit data through a data compression sensing algorithm, and generating a fault data report with a timestamp.

Description

Technical Field

[0001] The invention relates to a power differential protection method based on Beidou wide area timing, belonging to the technical field of power system protection. Background Art

[0002] Power differential protection is one of the important protection measures to ensure the safe operation of transmission lines in power systems. Its main function is to monitor and analyze the current differential at both ends of the transmission line to determine whether a fault has occurred and take corresponding tripping actions. Traditional power differential protection devices rely on the synchronization of local clock sources and current and voltage data to ensure the accuracy of protection actions. However, with the continuous expansion of the scale of modern power systems and the increasing complexity of power network structures, traditional differential protection devices have shown their limitations in some complex environments.

[0003] The first is that the time synchronization accuracy of traditional power differential protection is limited. Differential protection relies on real-time comparison of current data at both ends of the transmission line to determine whether there is an abnormality. Due to the large number of nodes in the power system and their wide distribution, traditional differential protection mainly achieves time synchronization through local clock sources or GPS timing signals. However, GPS signals are easily interfered in complex electromagnetic environments, and their accuracy and reliability cannot meet the requirements of differential protection for high-precision time synchronization in modern power systems. When the clocks are not synchronized, it may lead to misjudgment of the current phase angle, which in turn leads to misjudgment or missed faults, affecting the stable operation of the system.

[0004] The second is the lack of anti-interference ability. The power system usually works in a complex electromagnetic environment. External electromagnetic interference, line fluctuations and noise signals will have a great impact on the detection accuracy of traditional differential protection devices. The clock source of traditional differential protection devices is easily affected by these interferences, resulting in inaccurate timing or data transmission delays, which in turn affects the accuracy of fault judgment. In addition, the current data at both ends of the transmission line is subject to environmental noise and signal interference during the transmission process, further increasing the probability of the differential protection system misjudging faults.

[0005] The third is that the real-time data processing capability needs to be improved. As the scale of the power system increases and the complexity of operation increases, the amount of electrical quantity data in the transmission line also increases significantly. When processing these massive amounts of data, traditional differential protection devices have problems with slow response speed and insufficient processing capacity. Especially when large-scale faults occur or multiple faults occur at the same time, the system is prone to delays or even paralysis, and it is impossible to isolate the faulty line in time. In addition, the delay in data transmission and the limitation of computing power make it impossible for traditional differential protection devices to quickly and accurately complete fault detection and protection actions under certain high-load conditions. Summary of the invention

[0006] In order to solve the above problems existing in the prior art, the present invention proposes a power differential protection method based on Beidou wide area timing.

[0007] The technical solution of the present invention is as follows:

[0008] On the one hand, the present invention provides a method for power differential protection based on Beidou wide area timing, comprising the following steps:

[0009] Collect current and voltage data at both ends of the transmission line in the power system, synchronize the current and voltage data through Beidou wide-area timing signals, and then pre-process the synchronized current and voltage data;

[0010] Calculate the differential current and braking current of the transmission line through an adaptive differential current calculation algorithm based on the current and voltage data at both ends of the transmission line;

[0011] When the differential current of the transmission line exceeds a preset threshold, a trip command is issued to the circuit breaker to isolate the faulty transmission line through the circuit breaker;

[0012] The power data of the transmission line before and after the fault is recorded, the circuit data is compressed and marked through the data compression sensing algorithm, and a fault data report with a timestamp is generated.

[0013] As a preferred embodiment of the present invention, the preprocessing steps of the current data at both ends of the transmission line are:

[0014] The collected current data I1(t) and I2(t) at both ends of the transmission line are processed by multi-scale filtering, and high-frequency noise and low-frequency interference signals are removed by discrete wavelet transform to obtain current signal components I at different scale levels. 1，k (t) and I 2，k (t), where k represents the scale level of wavelet decomposition.

[0015] As a preferred embodiment of the present invention, the steps of calculating the differential current of the transmission line are:

[0016] The current signal components I at different scale levels 1，k (t) and I 2，k (t) are weighted combined to obtain the filtered current signals I′1(t) and I′2(t), as shown in the following formula:

[0017]

[0018] Where: n represents the number of scale levels; w k represents the weighting coefficient at the kth scale level;

[0019] Based on the filtered current signals I′1(t) and I′2(t), the differential current is calculated by a nonlinear mapping function, as shown in the following formula:

[0020] ΔI′(t)=tanh(I1′(t)-I2′(t));

[0021] Where: ΔI′(t) represents the differential current.

[0022] As a preferred embodiment of the present invention, the differential current ΔI′(t) is sparsely reconstructed by using the voltage data V1(t) and V2(t) through a compressed sensing algorithm to obtain a corrected differential current ΔI(t), which is specifically shown in the following formula:

[0023]

[0024] in: represents the coefficient reconstruction function of the differential current; β is the voltage correction coefficient.

[0025] As a preferred embodiment of the present invention, the preset differential current threshold is an adaptive adjustment threshold, which is adjusted according to the braking current I of the transmission line. b (t) and the corrected differential current ΔI(t) are calculated, as shown in the following formula:

[0026]

[0027] Where: ω is the adaptive adjustment coefficient; ∈ represents a constant.

[0028] As a preferred embodiment of the present invention, the specific steps of generating the fault data report with a timestamp are:

[0029] Record the current I of the transmission line before and after the fault f (t) data and perform filtering to remove transient noise signals caused by faults;

[0030] The current data I before and after the fault is analyzed by the data compression sensing algorithm. f (t) is compressed, as shown in the following formula:

[0031]

[0032] in: is the compressed current data; y is the compressed measurement vector;

[0033] For the compressed current data Sort by time sequence and add timestamp t s ;

[0034] Generates fault data reports based on compressed data with timestamps.

[0035] As a preferred embodiment of the present invention, the current data I before and after the fault is analyzed by using a data compression sensing algorithm. f (t) The specific steps for compression are:

[0036] The current data before and after the fault I f (t) According to the sampling frequency f s Perform discrete sampling to obtain the discrete time series I f [g], where g is the index of the sampling point;

[0037] The compression is performed through a nonlinear random projection matrix, as shown in the following formula:

[0038] y=tanh(A σ，θ I f [g]+b);

[0039] Among them: A σ，θ is a nonlinear random matrix containing noise disturbance parameters σ and random phase offset θ; b is the offset term;

[0040]

[0041] Where: α i , β j The current data before and after the fault are respectively i , The sparse representation coefficient under; k and m correspond to the sparsity respectively;

[0042] During the compression process, A σ，θ Satisfy the constraint isometry property, as shown in the following formula:

[0043]

[0044] Where: δ is the isometry constant; is the p-norm.

[0045] On the other hand, the present invention also provides a power differential protection system based on Beidou wide area timing, including a data acquisition module, a differential calculation module, a fault isolation module and a fault data generation module;

[0046] The data acquisition module is used to collect current and voltage data at both ends of the transmission line in the power system, synchronize the current and voltage data through the Beidou wide-area timing signal, and then pre-process the time-synchronized current and voltage data;

[0047] The differential calculation module is used to calculate the differential current and braking current of the transmission line through an adaptive differential current calculation algorithm based on the current and voltage data at both ends of the transmission line;

[0048] The fault isolation module is used to send a trip command to the circuit breaker when the differential current of the transmission line exceeds a preset threshold value, so as to isolate the faulty transmission line through the circuit breaker;

[0049] The fault data generation module is used to record the power data of the transmission line before and after the fault, compress and mark the circuit data through a data compression sensing algorithm, and generate a fault data report with a timestamp.

[0050] On the other hand, the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any embodiment of the present invention when executing the program.

[0051] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in any embodiment of the present invention.

[0052] The present invention has the following beneficial effects:

[0053] 1. The present invention significantly improves the time synchronization accuracy of key nodes in the power system by introducing Beidou wide-area timing technology, reaching the nanosecond level. Compared with the traditional power differential protection method that relies on local clock source or GPS timing, the present invention can provide more accurate time synchronization in complex electromagnetic environments, avoid fault detection inaccuracy caused by time error, and improve the overall reliability of the system.

[0054] 2. The present invention uses a compressed sensing algorithm to process fault data in the power system, and combines Beidou timing signals for timing marking and data compression. The algorithm has strong anti-interference ability, can effectively resist noise and external interference in complex electromagnetic environments, ensure the accuracy and integrity of fault data, and avoid the misjudgment or missed judgment problems of traditional differential protection methods under strong interference conditions.

[0055] 3. The present invention compresses fault data through a compressed sensing algorithm, greatly reducing the amount of data while ensuring data integrity, and improving the efficiency of data transmission and processing. When faced with a large amount of real-time data, the system can respond quickly and make fault judgments, significantly improving the real-time performance of the differential protection device. Especially in complex or large-scale power systems, the present invention can effectively solve the problem of slow response caused by data processing delays in traditional systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 The figure is a flow chart of the method of the present invention.

[0057] Figure 2 It is a structural diagram of the device of the present invention. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0060] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0061] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0062] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0063] Embodiment 1:

[0064] See also Figure 1 , a power differential protection method based on Beidou wide area timing, comprising the following steps:

[0065] Collect current and voltage data at both ends of the transmission line in the power system, synchronize the current and voltage data through Beidou wide-area timing signals, and then pre-process the synchronized current and voltage data;

[0066] Calculate the differential current and braking current of the transmission line through an adaptive differential current calculation algorithm based on the current and voltage data at both ends of the transmission line;

[0067] When the differential current of the transmission line exceeds a preset threshold, a trip command is issued to the circuit breaker to isolate the faulty transmission line through the circuit breaker;

[0068] The power data of the transmission line before and after the fault is recorded, the circuit data is compressed and marked through the data compression sensing algorithm, and a fault data report with a timestamp is generated.

[0069] As a preferred implementation of this embodiment, the preprocessing steps of the current data at both ends of the transmission line are:

[0070] The collected current data I1(t) and I2(t) at both ends of the transmission line are processed by multi-scale filtering, and high-frequency noise and low-frequency interference signals are removed by discrete wavelet transform to obtain current signal components I at different scale levels. 1，k (t) and I 2，k (t), where k represents the scale level of wavelet decomposition.

[0071] As a preferred implementation of this embodiment, the steps of calculating the differential current of the transmission line are:

[0072] The current signal components I at different scale levels 1，k (t) and I 2，k (t) are weighted combined to obtain the filtered current signals I′1(t) and I′2(t), as shown in the following formula:

[0073]

[0074] Where: n represents the number of scale levels; w k represents the weight coefficient at the kth scale level, which can be dynamically adjusted through an adaptive algorithm;

[0075] Based on the filtered current signals I′1(t) and I′2(t), the differential current is calculated by a nonlinear mapping function, as shown in the following formula:

[0076] ΔI′(t)=tanh(I1′(t)-I2′(t));

[0077] Where: ΔI′(t) represents the differential current.

[0078] As a preferred implementation of this embodiment, the differential current ΔI′(t) is sparsely reconstructed by using the voltage data V1(t) and V2(t) through a compressed sensing algorithm to obtain a corrected differential current ΔI(t), which is specifically shown in the following formula:

[0079]

[0080] in: represents the coefficient reconstruction function of the differential current; β is the voltage correction coefficient, which is dynamically adjusted according to the characteristics of the transmission line.

[0081] As a preferred implementation of this embodiment, the preset differential current threshold is an adaptive adjustment threshold, which is adjusted according to the braking current I of the transmission line. b (t) and the corrected differential current ΔI(t) are calculated, as shown in the following formula:

[0082]

[0083] Where: ω is the adaptive adjustment coefficient; ∈ represents a constant, which is used to avoid the denominator being zero.

[0084] As a preferred implementation of this embodiment, the specific steps of generating the fault data report with a timestamp are:

[0085] Record the current I of the transmission line before and after the fault f (t) data and perform filtering to remove transient noise signals caused by faults;

[0086] The current data I before and after the fault is analyzed by the data compression sensing algorithm. f (t) is compressed, as shown in the following formula:

[0087]

[0088] in: is the compressed current data; y is the compressed measurement vector;

[0089] For the compressed current data Sort by time sequence and add timestamp t s ;

[0090] Generate a fault data report based on compressed data with timestamps, which contains key electrical data before and after the fault occurs, time stamps, and preliminary fault determination information;

[0091] Transmit fault data reports to the remote monitoring center in real time for fault analysis and further processing;

[0092] At the same time, the fault data report and lock perception information are stored in the database for subsequent analysis and optimization.

[0093] As a preferred implementation of this embodiment, the current data I before and after the fault is analyzed by using a data compression sensing algorithm. f (t) The specific steps for compression are:

[0094] The current data before and after the fault I f (t) According to the sampling frequency f s Perform discrete sampling to obtain the discrete time series I f [g], where g is the index of the sampling point and the sampling frequency f s Real-time adjustment based on the operating status of the power system to optimize the accuracy of fault capture;

[0095] The compression is performed through a nonlinear random projection matrix, as shown in the following formula:

[0096] y=tanh(A σ，θ I f [g]+b);

[0097] Among them: A σ，θ is a nonlinear random matrix containing noise perturbation parameters σ and random phase offset θ, which is used to optimize the robustness of compression; b is the offset term, which optimizes the anti-interference performance;

[0098]

[0099] Where: α i , β j The current data before and after the fault are respectively i , The sparse representation coefficient under ; k and m are the corresponding sparsity, indicating the number of effective components in the signal; the sparsity of y can be reflected by the above formula;

[0100] During the compression process, A σ，θ Satisfy the constraint isometry property, as shown in the following formula:

[0101]

[0102] Among them: δ is the isometric constant, which controls the error range between the compressed signal and the original signal; is the p-norm, which is used to measure the degree of nonlinear distortion of signal compression.

[0103] At the same time, the noise disturbance parameter σ and phase shift θ in the compression matrix can be dynamically adjusted according to the operating status of the power system to meet the real-time data compression requirements under different fault conditions.

[0104] Embodiment 2:

[0105] A power differential protection system based on Beidou wide area timing, comprising a data acquisition module, a differential calculation module, a fault isolation module and a fault data generation module;

[0106] The data acquisition module is used to collect current and voltage data at both ends of the transmission line in the power system, synchronize the current and voltage data through the Beidou wide-area timing signal, and then pre-process the time-synchronized current and voltage data;

[0107] The differential calculation module is used to calculate the differential current and braking current of the transmission line through an adaptive differential current calculation algorithm based on the current and voltage data at both ends of the transmission line;

[0108] The fault isolation module is used to send a trip command to the circuit breaker when the differential current of the transmission line exceeds a preset threshold value, so as to isolate the faulty transmission line through the circuit breaker;

[0109] The fault data generation module is used to record the power data of the transmission line before and after the fault, compress and mark the circuit data through a data compression sensing algorithm, and generate a fault data report with a timestamp.

[0110] The system is used to implement the method in Example 1, which will not be described in detail here.

[0111] Embodiment three:

[0112] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any embodiment of the present invention when executing the program;

[0113] See also Figure 2 Specifically, in this embodiment, a power differential protection device based on Beidou wide area timing is proposed, including the following:

[0114] A current and voltage acquisition module is configured to acquire current and voltage data of the power system, reduce interference from external signals through an isolated acquisition scheme, and pre-process the acquired electrical quantity data;

[0115] Beidou receiving module, configured to receive wide-area timing signals from the Beidou satellite navigation system, obtain accurate time information through the antenna, and use signal processing technology to filter, amplify, and decode the received signals to extract nanosecond-level precision time synchronization information. The Beidou receiving unit also has an automatic calibration function, which can start the calibration procedure when the signal is deviated or interfered;

[0116] The data processing module is configured to support wired or wireless communication, realize high-speed data transmission with other power equipment, and process the transmitted electrical quantity data. The data is used for differential protection calculation. The communication and data processing module time-marks the electrical quantity data based on the Beidou timing signal and performs fault identification. When abnormal data is detected, the communication and data processing module generates fault data with a timestamp and interrupts operation to provide timing analysis support for fault processing. At the same time, the communication and data processing module also transmits the tripping or closing command issued by the control module to the corresponding equipment, and has data encryption and verification functions;

[0117] The control module is configured to receive the time synchronization signal output by the Beidou receiving unit and distribute the signal to various nodes of the power system. At the same time, the control module performs command control on the power differential protection device according to the results of the data processing unit, completes the differential protection action, and adjusts the operating parameters of the power system to realize differential protection.

[0118] Embodiment 4:

[0119] The power differential protection device and method based on Beidou wide area timing of the present invention are implemented in a medium-sized regional power grid in China. The regional power grid includes multiple substations and transmission lines, especially two main substations A and B connected on a 220kV transmission line. This transmission line is an important hub of the power grid, and its safe and stable operation is crucial to the entire regional power grid. However, the application effect of the traditional power differential protection system on this transmission line in the past was not ideal, mainly manifested in inaccurate time synchronization, resulting in inaccurate fault location and protection action.

[0120] In order to improve the protection accuracy of the transmission line, the power differential protection device based on Beidou wide area timing of the present invention is installed in substation A and substation B respectively. Each substation is equipped with a Beidou timing module, a data acquisition module, a data processing module and a control module. The antenna of the Beidou timing module is installed in an open place outdoors to ensure that a stable Beidou satellite signal is received. The antenna is connected to the Beidou timing module inside the substation via a cable to obtain a high-precision time synchronization signal. In addition, the control module is configured according to the parameters and protection requirements of the transmission line, and the parameters of the differential protection algorithm, such as the differential current threshold value and the braking coefficient, are set. The data processing module is connected to the communication module and other power equipment to ensure that the system can maintain real-time communication with the remote monitoring center.

[0121] In actual operation, the satellite signals received by the Beidou timing module provide nanosecond-level time synchronization signals for the power differential protection devices of substations A and B. Through this high-precision time synchronization, it is ensured that the devices of the two substations can maintain a high degree of consistency in time, providing a reliable time basis for subsequent differential protection calculations; the data acquisition module collects the current and voltage data at both ends of the transmission line in real time. After preliminary processing, these data are transmitted to the control module for further analysis. The data processing module adopts an adaptive differential current calculation algorithm. First, the current difference (differential current) and the sum (braking current) at both ends of the transmission line are calculated, and then the presence of a fault is determined based on the set differential current threshold value and braking coefficient. When the differential current exceeds the set threshold, the control module will immediately issue a trip command, which is transmitted to the circuit breaker through the communication module to isolate the fault line and prevent the fault from further expanding; in this process, the fault data will be compressed by the compressed sensing algorithm. The compressed data not only retains the key characteristics of the fault, but also can transmit the compressed data and fault report to the remote monitoring center in real time through the communication module. In this way, operators can understand the fault situation at the first time, and quickly locate and handle the fault.

[0122] In this embodiment, by applying the power differential protection device based on Beidou wide area timing of the present invention, the protection effect of the transmission lines of the regional power grid is significantly improved.

[0123] Table 1 Performance comparison data of power differential protection device based on Beidou wide area timing before and after implementation

[0124]

[0125]

[0126] As shown in Table 1, when applying the traditional method, due to the low time synchronization accuracy, the action of the differential protection device is often delayed, resulting in a large error in fault location, especially on a 220kV transmission line, the error is as high as 1000 meters. After installing the device of the present invention, the time synchronization accuracy is significantly improved, reaching nanosecond accuracy (0.01 microseconds), effectively reducing the action delay of the differential protection, and the trip response time is shortened to 40 milliseconds. At the same time, after the fault data is processed by the compressed sensing algorithm, the compression rate reaches 60%, which greatly reduces the amount of data, improves the data transmission efficiency, and shortens the data transmission delay from the original 60 milliseconds to 10 milliseconds.

[0127] Through practical application in this medium-sized regional power grid, the power differential protection device and method based on Beidou wide-area timing of the present invention effectively solves the problems of low time synchronization accuracy, poor anti-interference ability, and fault response delay encountered by traditional power differential protection devices in complex environments. In particular, when protecting key transmission lines, the device of the present invention can achieve accurate time synchronization in a complex electromagnetic environment to ensure the accuracy of the differential protection system. After a fault occurs, the device can respond quickly and reduce data transmission time through a compressed sensing algorithm, which greatly improves the efficiency of fault location and processing, and ultimately improves the stability and safety of the power system.

[0128] Embodiment five:

[0129] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method described in any embodiment of the present invention is implemented.

[0130] In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c can be single or multiple.

[0131] Those of ordinary skill in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented in a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0132] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0133] In several embodiments provided in the present application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory; hereinafter referred to as: ROM), random access memory (Random Access Memory; hereinafter referred to as: RAM), disk or optical disk, and other media that can store program codes.

[0134] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A power differential protection method based on Beidou wide area timing, characterized in that: The following steps are involved: Collect current and voltage data at both ends of the transmission line in the power system, synchronize the current and voltage data through Beidou wide-area timing signals, and then pre-process the synchronized current and voltage data; Calculate the differential current and braking current of the transmission line through an adaptive differential current calculation algorithm based on the current and voltage data at both ends of the transmission line; When the differential current of the transmission line exceeds a preset threshold, a trip command is issued to the circuit breaker to isolate the faulty transmission line through the circuit breaker; The power data of the transmission line before and after the fault is recorded, the circuit data is compressed and marked through the data compression sensing algorithm, and a fault data report with a timestamp is generated.

2. The method for power differential protection based on Beidou wide area timing according to claim 1 is characterized in that: The preprocessing steps of the current data at both ends of the transmission line are: The collected current data I1(t) and I2(t) at both ends of the transmission line are processed by multi-scale filtering, and high-frequency noise and low-frequency interference signals are removed by discrete wavelet transform to obtain current signal components I at different scale levels. 1,k (t) and I 2,k (t), where k represents the scale level of wavelet decomposition.

3. The method for power differential protection based on Beidou wide area timing according to claim 2 is characterized in that: The steps for calculating the differential current of the transmission line are: The current signal components I at different scale levels 1,k (t) and I 2,k (t) Perform weighted combination to obtain the filtered current signal I1 ′ (t) and I2 ′ (t), as shown in the following formula: Where: n represents the number of scale levels; w k represents the weighting coefficient at the kth scale level; Based on the filtered current signal I1 ′ (t) and I2 ′ (t), the differential current is calculated by the nonlinear mapping function, as shown in the following formula: ΔI′(t)=tanh(I1′(t)-I2′(t)); Where: ΔI′(t) represents the differential current.

4. The method for power differential protection based on Beidou wide area timing according to claim 3 is characterized in that: Using the voltage data V1(t) and V2(t), the differential current ΔI′(t) is sparsely reconstructed through the compressed sensing algorithm to obtain the corrected differential current ΔI(t), as shown in the following formula: in: represents the coefficient reconstruction function of the differential current; β is the voltage correction coefficient.

5. The method for power differential protection based on Beidou wide area timing according to claim 4 is characterized in that: The preset differential current threshold is an adaptive adjustment threshold, which is set according to the braking current I b (t) and the corrected differential current ΔI(t) are calculated, as shown in the following formula: Where: ω is the adaptive adjustment coefficient; ∈ represents a constant.

6. The method for power differential protection based on Beidou wide area timing according to claim 1 is characterized in that: The specific steps of generating the fault data report with timestamp are: Record the current I of the transmission line before and after the fault f (t) data and perform filtering to remove transient noise signals caused by faults; The current data I before and after the fault is analyzed by the data compression sensing algorithm. f (t) is compressed, as shown in the following formula: in: is the compressed current data; y is the compressed measurement vector; For the compressed current data Sort by time sequence and add timestamp t s ; Generates fault data reports based on compressed data with timestamps.

7. The method for power differential protection based on Beidou wide area timing according to claim 6 is characterized in that: The current data I before and after the fault is analyzed by the data compression sensing algorithm. f (t) The specific steps for compression are: The current data before and after the fault I f (t) According to the sampling frequency f s Perform discrete sampling to obtain the discrete time series I f [g], where g is the index of the sampling point; The compression is performed through a nonlinear random projection matrix, as shown in the following formula: y=tanh(A σ,θ ·I d [g]+b); Among them: A σ,θ is a nonlinear random matrix containing noise disturbance parameters σ and random phase offset θ; b is the offset term; Where: α i , β j The current data before and after the fault are respectively i , The sparse representation coefficient under; k and m correspond to the sparsity respectively; During the compression process, A σ,θ Satisfy the constraint isometry property, as shown in the following formula: Where: δ is the isometry constant; is the p-norm.

8. A power differential protection system based on Beidou wide area timing, characterized in that: It includes a data acquisition module, a differential calculation module, a fault isolation module and a fault data generation module; The data acquisition module is used to collect current and voltage data at both ends of the transmission line in the power system, synchronize the current and voltage data through the Beidou wide-area timing signal, and then pre-process the time-synchronized current and voltage data; The differential calculation module is used to calculate the differential current and braking current of the transmission line through an adaptive differential current calculation algorithm based on the current and voltage data at both ends of the transmission line; The fault isolation module is used to send a trip command to the circuit breaker when the differential current of the transmission line exceeds a preset threshold value, so as to isolate the faulty transmission line through the circuit breaker; The fault data generation module is used to record the power data of the transmission line before and after the fault, compress and mark the circuit data through a data compression sensing algorithm, and generate a fault data report with a timestamp.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

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

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