A data synchronization system and method for power distribution network terminal equipment under wireless communication

Abstract

The application discloses a kind of data synchronization system and method under power distribution network terminal equipment wireless communication, the system includes data acquisition module, mutation variable detection module, data matrix construction module, singular value decomposition module, synchronization point selection module and wireless synchronization module;The method obtains voltage sampling data by data acquisition module, identifies fault or disturbance trigger time by mutation variable detection module, constructs Hankel matrix after data matrix construction module, extracts effective intermediate by singular value decomposition module, determines synchronization point by synchronization point selection module, finally realizes cross-terminal synchronization with relative time scale data by wireless synchronization module.The application does not need to rely on external time service equipment and system parameter, algorithm is simple, real-time is good, anti-interference ability is strong, suitable for complex communication environment in mountainous area, tunnel etc., with extremely high engineering popularization value in 10kV power distribution network scene.

Description

Technical Field

[0001] This invention belongs to the field of power technology, specifically a data synchronization system and method for wireless communication of distribution network terminal equipment. Background Technology

[0002] Wireless communication is widely used in power distribution network terminal equipment, especially overhead line equipment, due to its advantages such as low construction cost, flexible expansion, and convenient construction. However, in practical engineering applications, multi-terminal data synchronization in a wireless communication environment faces many challenges, and existing technologies have obvious shortcomings:

[0003] (1) Traditional data synchronization methods rely on wired channels and use the ping-pong synchronization algorithm to achieve synchronization. However, wireless communication has problems such as large delay jitter and inconsistent two-way delay, which makes the traditional ping-pong synchronization algorithm unsuitable for wireless environments.

[0004] (2) Existing wireless synchronization solutions mostly rely on external satellites such as GPS for time synchronization. However, in mountainous areas, tunnels, dense forests and other areas, GPS signals are easily blocked or cannot be deployed, making it difficult to achieve stable time synchronization and increasing the hardware cost of the equipment.

[0005] (3) The fault detection synchronization method based on wavelet transform and curve fitting has a large amount of computation and poor real-time performance, which cannot meet the high real-time requirements of embedded power distribution terminals.

[0006] (4) The synchronous method based on load current and line parameter compensation requires clear line parameter information, but the line parameters are difficult to obtain accurately in engineering applications, which limits its practicality;

[0007] (5) The method of using current phasor information to locate the synchronization point by singular value decomposition is difficult to obtain current start-up information and set threshold values ​​in scenarios with a high proportion of distributed power supply access and small current on the weak feed side, making it difficult to promote in engineering.

[0008] Therefore, there is an urgent need to develop a self-synchronization method and system that does not rely on external time synchronization, is simple and fast to calculate, and has strong environmental adaptability, in order to solve the problem of data alignment among multiple terminals in the distribution network under wireless communication environment and ensure the accuracy of relay protection, monitoring and control functions. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a wireless communication data synchronization system and method for distribution network terminals based on voltage surge detection and singular value decomposition. This system eliminates the need for external timing devices and system parameters, enabling fast, accurate, and interference-resistant data synchronization and improving the reliability of data collaboration among distribution network terminals.

[0010] To achieve the above objectives, the present invention employs the following technical means:

[0011] A data synchronization system for wireless communication of power distribution network terminal equipment includes a data acquisition module, a mutation detection module, a data matrix construction module, a singular value decomposition module, a synchronization point selection module, and a wireless synchronization module that are connected in sequence.

[0012] The data acquisition module is used to sample the three-phase voltage amplitude and phase information at the distribution network terminal in real time, convert the analog signal into a digital signal, and transmit the digital signal to the sudden change detection module.

[0013] The mutation detection module is used to continuously monitor the voltage sampling sequence and determine whether a mutation exceeding a threshold occurs. If so, the mutation trigger time is recorded and a mutation amount marker is generated; otherwise, monitoring continues. At the same time, the mutation detection module performs multi-point continuity verification to prevent misjudgment.

[0014] The data matrix construction module is used to extract voltage mutation data within one cycle before and after the mutation time after receiving the mutation amount marker, and construct a Hankel matrix based on the voltage mutation amount data.

[0015] The singular value decomposition module is used to perform singular value decomposition operations on the Hankel matrix, analyze and determine the effective intervals;

[0016] The synchronization point selection module is used to identify the modulus maxima in the effective intermediate data obtained by singular value decomposition, and select the modulus maxima before the voltage change start-up time and at the start-up time as synchronization points.

[0017] The wireless synchronization module is used to mark the local time of the synchronization point, add a relative time stamp to each sampling point, and send the data with the relative time stamp to the peer terminal through the wireless network.

[0018] Preferably, the sampling rate of the data acquisition module is 1200Hz, which is 24 sampling points per cycle.

[0019] Preferably, the mutation judgment threshold of the mutation detection module is determined by the formula... Confirmed, among which This represents the number of sampling points per wave. This is the voltage sample value at the current moment. For the sampled value corresponding to one cycle, These are the corresponding sampled values ​​from two cycles ago. It is 0.1 times the rated voltage. This is the rated voltage value.

[0020] Preferably, in the Hankel matrix constructed by the data matrix construction module, the voltage mutation data array has a length N=24 and the number of matrix columns n=4.

[0021] Preferably, the Hankel matrix has the following specific form:

[0022]

[0023] in, This represents the voltage change data for the cycle preceding the sudden change.

[0024] A method for implementing a data synchronization system under wireless communication for power distribution network terminal equipment includes the following steps:

[0025] Step 1: The data acquisition module continuously samples the three-phase voltage data at the distribution network terminal at a preset sampling rate. After completing the analog-to-digital conversion, the resulting digital sequence is transmitted to the sudden change detection module.

[0026] Step 2: The mutation detection module continuously monitors the digital sequence to determine whether a voltage mutation exceeding the threshold occurs;

[0027] Step 3: When a voltage surge is detected, the data matrix construction module extracts the voltage surge data within a preset time window and constructs a Hankel matrix;

[0028] Step 4: The singular value decomposition module performs singular value decomposition operations on the Hankel matrix and determines the valid intermediate order;

[0029] Step 5: The synchronization point selection module identifies the modulus maxima based on the valid intermediate data and filters out the synchronization points;

[0030] Step 6: The wireless synchronization module adds a relative timestamp based on the synchronization point to the data and sends it to the peer terminal via the wireless network.

[0031] Preferably, step 2 specifically includes: the mutation detection module determines whether a mutation is triggered by continuously comparing the voltage sampling sequence and using the condition that "the amplitude change of three consecutive sampling points is greater than 10% of the rated voltage": if yes, the moment is recorded and a mutation amount marker is generated, and single-point glitches are eliminated through multi-point continuity verification; if no, it returns to continue monitoring subsequent sampling points.

[0032] Preferably, in step 4, the effective intermediate order is determined by the singular value transform rate, and the formula for calculating the singular value transform rate is:

[0033]

[0034] in, For the first A singular value, select corresponding The value is used as a valid intermediate.

[0035] Preferably, in step 5, the specific basis for selecting the synchronization point is: selecting the modulus maximum point corresponding to the voltage surge initiation time and the initiation time as the final synchronization point.

[0036] Preferably, in step 6, the wireless synchronization module marks the local time of the synchronization point. Add a relative time scale to each sampling point ,in, This refers to the local sampling time at the sampling point.

[0037] The present invention has the following beneficial effects:

[0038] 1. Wide range of applications: It does not require obtaining distribution network system parameters and load information, is not affected by fault type or distributed power source access ratio, and can be adapted to distribution network scenarios with different topologies.

[0039] 2. High synchronization accuracy: It is not affected by the initial angle of the fault. By extracting the detailed components of the fault through singular value decomposition, it can avoid the synchronization delay problem caused by small voltage changes at the far fault end. The synchronization error is controlled within 1 sampling point.

[0040] 3. No external time synchronization required: It does not rely on satellite equipment such as GPS, which reduces hardware costs and solves the problem of unstable time synchronization in complex environments.

[0041] 4. Good real-time performance and compatibility: The algorithm is based on basic matrix operations, with low computational load, and can be directly embedded into embedded power distribution terminals; the sampling rate and threshold parameters can be flexibly adjusted to adapt to power distribution networks of different voltage levels.

[0042] 5. High engineering value: It has strong anti-electromagnetic interference capability and good environmental adaptability. It can be promoted in complex scenarios such as mountainous areas and tunnels. It is especially suitable for 10kV overhead distribution networks, with low deployment cost and convenient operation and maintenance. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the data synchronization system of the present invention;

[0044] Figure 2 This is a flowchart of the data synchronization method of the present invention;

[0045] In the attached figures, the following labels are used:

[0046] Data acquisition module 1, mutation detection module 2, data matrix construction module 3, singular value decomposition module 4, synchronization point selection module 5, wireless synchronization module 6. Detailed Implementation

[0047] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] like Figure 1 As shown, a data synchronization system for wireless communication of power distribution network terminal equipment includes a data acquisition module 1, a mutation detection module 2, a data matrix construction module 3, a singular value decomposition module 4, a synchronization point selection module 5, and a wireless synchronization module 6, which are connected in sequence.

[0049] The modular system design described above effectively solves the data synchronization problem in wireless communication environments described in the background technology through the collaborative work of its modules. Its core lies in a two-stage high-precision synchronization point identification mechanism comprised of a sudden change detection module 2 and a singular value decomposition module 4. First, by using voltage sudden changes as the synchronization trigger signal, the problem of detecting weak feed-side current signals is overcome, and it is independent of line parameters. Second, by performing singular value decomposition on the Hankel matrix constructed from the sudden change data and extracting the effective intermediate components reflecting fault details, the synchronization point is located. This method is insensitive to changes in the initial phase angle and amplitude of the fault, thus solving the problem of synchronization delay or large errors caused by gradual voltage changes at the far fault end. Finally, the wireless synchronization module 6 only needs to transmit a relative time stamp generated based on the local synchronization point, completely avoiding the cost, environmental, and latency jitter problems caused by relying on external time synchronization or two-way time synchronization. The entire system achieves the beneficial effects of being independent of external time synchronization and system parameters, having low computational load, high synchronization accuracy, and strong environmental adaptability.

[0050] Further details regarding the functions and collaboration of each module are as follows:

[0051] 1) Data Acquisition Module 1: Its core function is to acquire the three-phase voltage amplitude and phase information at the distribution network terminal in real time. It uses a high sampling rate of 1200Hz (24 points per cycle) for continuous recording. The analog voltage signal is converted into a digital signal through the A / D conversion interface and transmitted to the subsequent processing module. It can also be expanded to acquire current and other status data to provide redundant support for synchronous verification.

[0052] 2) Sudden Change Detection Module 2: Continuously monitors the acquired voltage time series and determines whether a sudden change has occurred based on a preset threshold. The formula is used... As a basis for judging mutations, among them (Number of sampling points per wave) (i.e., 10% of the rated voltage); when three consecutive sampling points meet the above conditions, it is determined to be a fault or disturbance trigger, the current time is recorded and a sudden change mark is generated; at the same time, multi-point continuity verification is performed to eliminate misjudgments caused by external interference such as single-point glitches.

[0053] 3) Data Matrix Construction Module 3: After receiving the mutation amount marker, it retrieves the voltage mutation amount data of the cycle preceding the mutation trigger time from the memory, and the data array. Construct the array into a Hankel matrix, with the matrix form as follows:

[0054] ;

[0055] The voltage fluctuation data array has a length of N=24 and a matrix column count of n=4. This matrix has a small data volume, which can meet the needs of real-time calculation. The core reason for selecting voltage fluctuation data to construct the matrix is ​​that the voltage fluctuations at both ends originate from the same fault power source, have the same initial phase angle, and only differ in amplitude. The data after singular value decomposition have similarity, which can ensure the consistency of the selection of synchronization points.

[0056] 4) Singular Value Decomposition Module 4: Performs singular value decomposition operations on the constructed Hankel matrix, as follows:

[0057] for Then it exists orthogonal matrix of order and orthogonal matrix of order , making;

[0058] ;

[0059] in, , For matrix All non-zero singular values ​​satisfy , .

[0060] Decomposable into ;

[0061] in, , , , ;

[0062] Will Decomposed into Let matrices be and let , , can be obtained;

[0063] ;

[0064] Will The first row and last column are combined to form a new signal sequence:

[0065] ;

[0066] The original data signal sequence is then decomposed into:

[0067] ;

[0068] Singular value decomposition can decompose a signal into a series of components, where... The largest singular component is the main part of the original signal. This can reflect detailed signals. In order to select the fault moment, it is necessary to find a suitable signal component that reflects the information of the fault component.

[0069] The value with the largest transformation rate is selected as the effective intermediate order of the singular value, which can be expressed as shown in the equation.

[0070] ;

[0071] beg The maximum conversion rate corresponding to The value can be used as an effective intermediate in singular value analysis, that is... Arrays are used to analyze detailed components.

[0072] 5) Synchronization Point Selection Module 5: Identifies modulo maxima points in the valid intermediate data, and combines them with the mutation start time recorded by the mutation detection module 2 to select modulo maxima points before (including) the mutation start time as the final synchronization points. The advantage of this selection principle is that singular value decomposition is more sensitive to fault details, and the occurrence time of the identified modulo maxima points is no later than the voltage mutation start time, which can avoid the problem of synchronization delay at the far fault end caused by simply relying on voltage mutation.

[0073] 6) Wireless synchronization module 6: Marks the local time of the synchronization point Add a relative time scale to each sampling point ( (This refers to the local sampling time of the sampling point); the sampling data with relative time stamp is sent to the peer terminal via a wireless network (such as LoRa or 5G narrowband); after receiving the data, the peer terminal can achieve accurate alignment with the local data based on the relative time stamp information.

[0074] like Figure 2 As shown, a data synchronization method for wireless communication in power distribution network terminal equipment.

[0075] This method is based on the above system and the specific steps are as follows:

[0076] Step 1: Data Acquisition Initialization. After the data acquisition module 1 is started, it continuously acquires three-phase voltage data at a sampling rate of 1200Hz. After A / D conversion, the data is transmitted to the sudden change detection module 2 in real time, and the raw data is stored in the local memory.

[0077] Step 2: Voltage Sudden Change Detection. The sudden change detection module 2 uses the formula... The voltage change is continuously calculated. When three consecutive sampling points meet the condition, the trigger time t0 is recorded, a sudden change marker is generated and sent to the data matrix construction module 3. If only one or two sampling points meet the condition, it is judged as interference and no marker is generated.

[0078] Step 3: Hankel Matrix Construction. After receiving the abrupt change marker, the data matrix construction module 3 extracts the voltage abrupt change data for the one cycle preceding time t0 (i.e., from t0-20ms to t0) from the memory, forming an array. Construct the array into a 4-column, 21-row Hankel matrix. .

[0079] Step 4: Singular Value Decomposition and Determination of Effective Intermediate Order. The Singular Value Decomposition module 4 performs matrix... Perform singular value decomposition to obtain a sequence of singular values. ; Calculate the transformation rate of each singular value ,turn up corresponding Value, extract the decomposition data of this level. .

[0080] Step 5: Synchronization Point Selection. The synchronization point selection module has 5 pairs. The data undergoes modulo-maxima detection to obtain the times corresponding to multiple modulo-maxima points; the modulo-maxima points with times ≤ t0 are selected, and these points are the synchronization points. .

[0081] Step 6: Wireless synchronization is implemented. The wireless synchronization module 6 adds a relative time stamp to all local sampling points. The time-stamped data is sent to the peer terminal via a wireless network. After receiving the data, the peer terminal adjusts the time stamp of the received data based on its own recognized synchronization point to achieve synchronization and alignment of the data on both sides.

[0082] Example 1

[0083] Synchronous Scenario of Phase-A Short Circuit Fault in 10kV Overhead Distribution Network

[0084] 1. Experimental Environment Setup: Select a 10kV overhead power distribution line and install terminal M and terminal N at both ends of the line respectively. Both terminals are equipped with the synchronization system described in this invention. The terminal sampling rate is set to 1200Hz (24 points per cycle), and the mutation detection threshold is set to 10% of the rated voltage (i.e., 1kV). The two terminals communicate through a LoRa wireless network with a communication delay ≤50ms.

[0085] 2. Fault Triggering and Data Acquisition: An A / B phase-to-phase short-circuit fault is set in the middle section of the line, and the fault occurs at t=10s; Terminal M and Terminal N simultaneously start voltage acquisition and transmit it to the sudden change detection module in real time.

[0086] 3. Sudden Voltage Change Detection: Due to its proximity to the fault point, terminal M experiences a significant voltage change. At t=10.002s, three consecutive sampling points meet the requirements. Record t0 = M10.002s and generate a mutation amount marker; Terminal N is far from the fault point, and the voltage changes slowly. At t = 10.005s, the mutation condition is met, and record t0 = N10.005s and generate a marker.

[0087] 4. Matrix Construction and Singular Value Decomposition: Voltage abrupt change data for the first cycle (20ms) before t0 are extracted from both terminals, and a 21×4 Hankel matrix is ​​constructed. Singular value decomposition is performed on the matrix to calculate the singular value transformation rate of terminal M. For k=2, terminal N Similarly, for k=2, all are extracted data.

[0088] 5. Synchronization point selection: Terminal M in The data detected a modulus maximum point at 10.001s (≤t0=M10.002s), which was determined to be a synchronization point. Terminal N in The data detected a point where the modulus maximum was also 10.001s (≤t0=N10.005s), which was determined to be a synchronization point. .

[0089] 6. Wireless Synchronization and Alignment: Both terminals add relative time stamps to their own sampled data and exchange data via the LoRa network; after receiving the time-stamped data from terminal N, terminal M synchronizes the data based on... Time-scale calibration is performed, and the same applies to terminal N; ultimately, accurate alignment of data on both sides is achieved, with a synchronization error of 0.83ms (1 sampling point, 1 / 1200Hz≈0.83ms), which meets the accuracy requirements of relay protection for data synchronization.

[0090] The examples provided in this invention are not intended to limit the implementation. Those skilled in the art will recognize that various variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations, and any obvious variations or modifications derived therefrom are still within the scope of this invention.

[0091] The above-mentioned invention patent is modified as follows: In the specific implementation method, "such as..." Figure 1 As shown, "A data synchronization system for wireless communication of distribution network terminal equipment". This section should first describe the content of claim 1 in the first paragraph, and then describe in the second paragraph how the technical features solve the problems in the background technology and what effects are achieved. This is the current writing method.

Claims

1. A data synchronization system for wireless communication in power distribution network terminal equipment, characterized in that, It includes a data acquisition module (1), a mutation detection module (2), a data matrix construction module (3), a singular value decomposition module (4), a synchronization point selection module (5), and a wireless synchronization module (6) that are connected in sequence. The data acquisition module (1) is used to sample the three-phase voltage amplitude and phase information at the distribution network terminal in real time, convert the analog signal into a digital signal, and transmit the digital signal to the sudden change detection module (2). The mutation detection module (2) is used to continuously monitor the voltage sampling sequence and determine whether a mutation exceeding the threshold occurs: if so, the mutation trigger time is recorded and a mutation amount marker is generated; if not, monitoring continues; at the same time, the mutation detection module (2) completes multi-point continuity verification to prevent misjudgment. The data matrix construction module (3) is used to extract voltage mutation data within one cycle before and after the mutation time after receiving the mutation amount marker, and construct a Hankel matrix based on the voltage mutation amount data. The singular value decomposition module (4) is used to perform singular value decomposition operations on the Hankel matrix, analyze and determine the effective intervals; The synchronization point selection module (5) is used to identify the modulus maxima in the effective intermediate data obtained by singular value decomposition, and select the modulus maxima before the voltage change start time and at the start time as synchronization points. The wireless synchronization module (6) is used to mark the local time of the synchronization point, add a relative time stamp to each sampling point, and send the data with the relative time stamp to the peer terminal through the wireless network.

2. The data synchronization system for wireless communication of power distribution network terminal equipment according to claim 1, characterized in that, The sampling rate of the data acquisition module (1) is 1200Hz, which is 24 sampling points per cycle.

3. The data synchronization system for wireless communication of power distribution network terminal equipment according to claim 1, characterized in that, The mutation detection module (2) determines the mutation threshold using the formula. Confirmed, among which This represents the number of sampling points per wave. This is the voltage sample value at the current moment. For the sampled value corresponding to one cycle, These are the corresponding sampled values ​​from two cycles ago. It is 0.1 times the rated voltage. This is the rated voltage value.

4. A data synchronization system for wireless communication in a power distribution network terminal equipment according to claim 1, characterized in that, In the Hankel matrix constructed by the data matrix construction module (3), the voltage mutation data array has a length of N=24 and the number of matrix columns n=4.

5. A data synchronization system for wireless communication of power distribution network terminal equipment according to claim 4, characterized in that, The specific form of the Hankel matrix is ​​as follows: in, This represents the voltage change data for the cycle preceding the sudden change.

6. A method for implementing a data synchronization system based on wireless communication of distribution network terminal equipment according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: The data acquisition module (1) continuously samples the three-phase voltage data at the distribution network terminal at a preset sampling rate. After completing the analog-to-digital conversion, the obtained digital sequence is transmitted to the sudden change detection module (2). Step 2: The mutation detection module (2) continuously monitors the digital sequence to determine whether a voltage mutation exceeding the threshold occurs; Step 3: When a voltage surge is detected, the data matrix construction module (3) extracts the voltage surge data within a preset time window and constructs a Hankel matrix; Step 4: The singular value decomposition module (4) performs singular value decomposition operation on the Hankel matrix and determines the valid intermediate order; Step 5: The synchronization point selection module (5) identifies the modulus maxima based on the effective intermediate data and filters out the synchronization points; Step 6: The wireless synchronization module (6) adds a relative timestamp based on the synchronization point to the data and sends it to the peer terminal via the wireless network.

7. The implementation method of a data synchronization system under wireless communication for power distribution network terminal equipment according to claim 6, characterized in that, Step 2 specifically includes: The mutation detection module (2) uses the condition of "the amplitude change of three consecutive sampling points is greater than 10% of the rated voltage" to determine whether the mutation is triggered by continuously comparing the voltage sampling sequence. If yes, the moment is recorded and a mutation mark is generated. At the same time, single-point glitch interference is eliminated by multi-point continuity verification. If no, it returns to continue monitoring subsequent sampling points.

8. The method for implementing a data synchronization system under wireless communication for distribution network terminal equipment according to claim 6, characterized in that, In step 4, the effective intermediate order is determined by the singular value transform rate, and the formula for calculating the singular value transform rate is: in, For the first A singular value, select corresponding The value is used as a valid intermediate.

9. The implementation method of a data synchronization system under wireless communication for distribution network terminal equipment according to claim 6, characterized in that, In step 5, the specific basis for selecting the synchronization point is: the modulus maximum point corresponding to the voltage change start time and the start time is selected as the final synchronization point.

10. The implementation method of a data synchronization system under wireless communication for power distribution network terminal equipment according to claim 6, characterized in that, In step 6, the wireless synchronization module (6) marks the local time of the synchronization point. Add a relative time scale to each sampling point ,in, This refers to the local sampling time at the sampling point.

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