Power distribution network distributed measurement synchronization method and device based on beidou satellite timing

Abstract

The application discloses a power distribution network distributed measurement synchronization method and device based on Beidou satellite timing, and belongs to the technical field of power distribution network measurement, which comprises the following steps: acquiring Beidou satellite signals to calibrate local clock sources and generate a standard time reference; when continuously monitoring the quality parameter of the Beidou satellite signals is lower than a quality threshold, collecting clock working environment parameters of the local clock sources and combining the standard time reference to generate a short-term clock offset prediction value; generating a topological correction amount according to the topological connection relationship of the power distribution network; and fusing the short-term clock offset prediction value and the topological correction amount to generate a dynamic compensation time reference, time marking the collected electrical quantity measurement data of the power distribution network, and generating time-stamped synchronous measurement data. The technical scheme of fusing the local clock drift prediction value and the adjacent node topological correction amount to generate the dynamic compensation time reference when the Beidou signal is lost can significantly improve the precision and robustness of the measurement data synchronization of the power distribution network in a complex environment.

Description

Technical Field

[0001] This invention relates to the field of power distribution network measurement technology, and in particular to a method and apparatus for distributed measurement synchronization of power distribution networks based on BeiDou satellite timing. Background Technology

[0002] As a crucial component of the power system, the safe, stable, and economical operation of the distribution network is of paramount importance. With the increasing integration of distributed power sources and rising user demands for power supply reliability, the operation and control of the distribution network are becoming increasingly complex. To achieve refined monitoring and efficient management of the distribution network, it is necessary to deploy measuring devices at key nodes along the lines to collect real-time data on electrical quantities such as voltage, current, and phase. This high-precision, timestamped, synchronous measurement data forms the foundation for advanced applications such as accurate fault location, system state estimation, and power flow analysis.

[0003] To ensure time consistency of data collected by distributed measuring devices in different geographical locations, existing technologies typically employ Global Navigation Satellite Systems (GNSS) for timing. For example, they utilize pulse-per-second (1PPS) signals and time information provided by the BeiDou Navigation Satellite System (BDS) or the Global Positioning System (GPS) to synchronize the local clocks of each measuring device. This timing method achieves extremely high synchronization accuracy in open areas with good satellite signal coverage and no obstructions, meeting the application requirements of power distribution networks.

[0004] However, in real-world power distribution network environments, numerous measuring devices are installed in complex locations such as urban canyons, indoor substations, and underground cable trenches. Satellite signals in these areas are easily blocked or interfered with by tall buildings, trees, or other obstacles, leading to signal weakening or even interruption. Once the satellite signal is lost, the measuring devices can only rely on their internal local clock source (such as a crystal oscillator) for timekeeping. However, the frequency of the local clock source is affected by environmental factors such as temperature and voltage fluctuations, causing drift. Prolonged timekeeping accumulates significant time errors, resulting in a loss of synchronization between measuring nodes and severely impacting the accuracy and effectiveness of subsequent power grid analysis applications. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a distributed measurement synchronization method and apparatus for power distribution networks based on BeiDou satellite timing. It employs a technical solution that integrates local clock drift predictions with topology corrections from adjacent nodes to generate a dynamic compensation time reference when BeiDou signals are lost. This significantly improves the accuracy and robustness of measurement data synchronization in power distribution networks under complex environments.

[0006] The above objectives can be achieved through the following approach: A distributed measurement synchronization method for power distribution networks based on BeiDou satellite timing includes: acquiring BeiDou satellite signals and calibrating a local clock source according to the BeiDou satellite signals to generate a standard time reference; continuously monitoring the real-time status of the BeiDou satellite signals, generating signal quality parameters, and generating a dynamic compensation mode trigger signal when the signal quality parameters are lower than a preset quality threshold; responding to the dynamic compensation mode trigger signal, collecting clock operating environment parameters of the local clock source, and combining the standard time reference with the clock operating environment parameters to predict drift characteristics and generate a short-term clock offset prediction value; determining a set of topologically adjacent nodes based on the power distribution network topology connection relationship, sending a time synchronization request to the set of topologically adjacent nodes to obtain the timestamps of adjacent nodes, calculating the theoretical time difference based on the line physical parameters included in the power distribution network topology connection relationship, correcting the timestamps of adjacent nodes using the theoretical time difference, and generating a topology correction amount; fusing the short-term clock offset prediction value and the topology correction amount to generate a dynamic compensation time reference; collecting electrical quantity measurement data of the power distribution network, and using the dynamic compensation time reference to time-stamp the electrical quantity measurement data to generate time-stamped synchronized measurement data.

[0007] Optionally, generating the dynamic compensation mode trigger signal includes: collecting the number of receiving satellites, signal-to-noise ratio, and position accuracy factor of the BeiDou satellite signal to form original state data; performing a weighted comprehensive evaluation on the original state data to generate the signal quality parameters; obtaining the critical performance index used to characterize the signal from reliable to unreliable to generate a quality threshold; and generating a dynamic compensation mode trigger signal when the signal quality parameters are lower than the preset quality threshold.

[0008] Optionally, the step of acquiring the clock operating environment parameters of the local clock source and combining them with the standard time reference to predict drift characteristics and generate short-term clock offset prediction values ​​includes: acquiring the real-time operating temperature and power supply voltage of the local clock source to form clock operating environment parameters; establishing a drift characteristic prediction model to describe the correspondence between clock frequency drift and the clock operating environment parameters; inputting the real-time acquired clock operating environment parameters into the drift characteristic prediction model, combining the standard time reference as the initial state, and calculating and outputting short-term clock offset prediction values.

[0009] Optionally, establishing a drift characteristic prediction model to describe the correspondence between clock frequency drift and the clock operating environment parameters includes: continuously recording clock operating environment parameters under different operating conditions when the signal quality parameter is greater than the quality threshold; continuously comparing the actual time of the local clock source with the standard time reference to obtain actual clock drift data corresponding to the clock operating environment parameters; and generating a drift characteristic prediction model based on the multivariate correspondence between the clock operating environment parameters and the actual clock drift data by training through fitting or machine learning methods.

[0010] Optionally, generating the topology correction includes: determining a set of topologically adjacent nodes based on the distribution network topology connection relationship, and sending a time synchronization request to the set of topologically adjacent nodes to obtain the timestamps of the adjacent nodes; extracting line physical parameters from the distribution network topology connection relationship, and calculating the theoretical time difference of signal propagation between nodes based on the line physical parameters; calculating the measured time difference by combining the received timestamps of the adjacent nodes with the time when the local time synchronization request was sent; and subtracting the theoretical time difference and network communication delay from the measured time difference to generate the topology correction.

[0011] Optionally, sending a time synchronization request to the set of topological neighboring nodes to obtain neighboring node timestamps includes: sending a time synchronization request to the set of topological neighboring nodes and receiving multiple returned neighboring node timestamps to form an initial timestamp group; evaluating the consistency and validity of each timestamp in the initial timestamp group, removing outliers or abnormal values, and generating a preferred timestamp group; and averaging or weighted averaging the timestamps in the preferred timestamp group to generate neighboring node timestamps.

[0012] Optionally, the step of fusing the short-term clock offset prediction value and the topology correction amount to generate a dynamic compensation time reference includes: acquiring a node timing quality index that characterizes the timing status of the node from which the neighboring node timestamps are sourced, while acquiring the timestamps of the neighboring nodes; when the timing quality index of a node with topologically adjacent nodes is higher than a preset autonomous operation threshold, generating a dynamic fusion weight based on the node timing quality index to adjust the confidence level of the topology correction amount and the short-term clock offset prediction value; and using the dynamic fusion weight, performing a weighted summation of the short-term clock offset prediction value and the topology correction amount to generate the dynamic compensation time reference.

[0013] Optionally, the method further includes: when the node timing quality index of all topologically adjacent nodes is lower than the autonomous operation threshold, obtaining the neighboring node timestamps of all nodes in the topologically adjacent node set to form a regional timestamp set; using the dispersion of the neighboring node timestamps in the regional timestamp set, and with minimizing the dispersion as the objective, establishing an objective optimization function, and solving for the topology correction amount corresponding to minimizing the dispersion; and updating the current topology correction amount using the topology correction amount corresponding to minimizing the dispersion.

[0014] Optionally, after generating the dynamic compensation time reference, the method further includes: continuously monitoring the real-time status of the BeiDou satellite signal and updating the signal quality parameters; determining whether the updated signal quality parameters within a preset time window are lower than the quality threshold; if not, terminating the use of the dynamic compensation time reference and re-executing the calibration of the local clock source based on the BeiDou satellite signal to obtain an updated standard time reference; and using the updated standard time reference to time-mark the electrical quantity measurement data.

[0015] Based on the same inventive concept, this invention also provides a distributed measurement synchronization device for power distribution networks based on BeiDou satellite time synchronization. The device includes: a BeiDou calibration module for acquiring BeiDou satellite signals and calibrating a local clock source according to the BeiDou satellite signals to generate a standard time reference; a signal quality monitoring module for continuously monitoring the real-time status of the BeiDou satellite signals, generating signal quality parameters, and generating a dynamic compensation mode trigger signal when the signal quality parameters are lower than a preset quality threshold; and a drift characteristic prediction module for responding to the dynamic compensation mode trigger signal, acquiring clock operating environment parameters of the local clock source, and combining the standard time reference with the clock operating environment parameters to predict drift characteristics and generate short-term... The system includes: a clock offset prediction value; a topology information interaction module, used to determine the set of adjacent nodes based on the distribution network topology connection relationship, and send a time synchronization request to the set of adjacent nodes to obtain the timestamps of the adjacent nodes, then calculate the theoretical time difference by combining the line physical parameters contained in the distribution network topology connection relationship, and use the theoretical time difference to correct the timestamps of the adjacent nodes to generate a topology correction amount; a time base fusion module, used to fuse the short-term clock offset prediction value and the topology correction amount to generate a dynamic compensation time base; and a timestamp generation module, used to collect electrical quantity measurement data of the distribution network, and use the dynamic compensation time base to time-stamp the electrical quantity measurement data to generate time-stamped synchronized measurement data.

[0016] Compared with the prior art, the present invention has the following advantages: 1. When the BeiDou satellite signal is reliable, this invention directly calibrates the local clock using high-precision satellite signals, ensuring that the reference time of the measurement data has extremely high accuracy. When the BeiDou signal becomes unreliable due to obstruction or other reasons, the device can seamlessly switch to an innovative dynamic compensation mode. By combining the prediction of the physical characteristics of the device's own clock with network collaborative correction using the power grid topology, time drift is effectively suppressed, thus maintaining the synchronization of measurements even in harsh environments and ensuring the availability and reliability of data at all times. 2. This invention learns and establishes a mathematical model of clock drift and environmental factors such as temperature and voltage in an offline state, enabling the measuring device to perform high-precision self-time calibration based on its own environmental perception after the loss of an external time source. This method fundamentally solves the problem of excessive frequency drift caused by environmental changes in traditional crystal oscillators in timekeeping mode, and significantly improves the time maintenance accuracy of the device during autonomous operation. 3. This invention introduces a collaborative time synchronization mechanism based on the distribution network topology. When the time synchronization signal of a single node is lost, it can actively communicate with its neighboring nodes and obtain a topology-corrected time reference by utilizing physical connection relationships and line parameters. Furthermore, in the extreme case of regional signal interruption, this invention also designs a network-wide collaborative optimization mechanism to maintain the relative time consistency of the entire network by minimizing the dispersion of node clocks within the region. This distributed and adaptive time synchronization strategy greatly enhances the resilience and robustness of the entire measurement device.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the distributed measurement synchronization method for power distribution networks based on BeiDou satellite time synchronization, according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of a distributed measurement and synchronization device for power distribution networks based on BeiDou satellite time synchronization, according to an embodiment of the present invention.

[0021] Figure 3 This is a comparison chart of node time errors under different synchronization modes in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. 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.

[0023] Reference Figure 1 One embodiment of the present invention proposes a distributed measurement synchronization method for distribution networks based on BeiDou satellite time synchronization. The method adopts a technical solution that integrates the local clock drift prediction value and the topology correction amount of adjacent nodes to generate a dynamic compensation time reference when the BeiDou signal is lost. This method can significantly improve the accuracy and robustness of measurement data synchronization in distribution networks under complex environments.

[0024] The method described in this embodiment specifically includes: Acquire BeiDou satellite signals and calibrate the local clock source based on the BeiDou satellite signals to generate a standard time reference; Specifically, the first step is to equip the measuring device with a BeiDou time receiver. This receiver, equipped with an antenna, continuously receives L-band radio frequency signals broadcast from the BeiDou Navigation Satellite System and decodes them to extract precise time information. The core of acquiring BeiDou satellite signals lies in separating two key types of time data from the decoded navigation message: a serial time message containing the year, month, day, hour, minute, and second, and a high-precision 1PPS (1 second pulse) signal. The 1PPS is a physical level signal whose rising edge is precisely aligned with the second boundary of Coordinated Universal Time (UTC), ensuring extremely high accuracy. The local clock source is typically a high-stability crystal oscillator within the measuring device, such as a temperature-compensated crystal oscillator (TCXO). It maintains the local time by generating a stable frequency signal to drive an internal counter. Calibrating the local clock source involves accurately comparing and correcting the local time with BeiDou satellite time. This begins by reading the serial time message to coarsely set the local clock source's counter, aligning it with the standard time at the second level. Subsequently, the fine calibration phase begins. Using the precise second edge of the 1PPS second pulse signal as an external trigger event, the local clock source captures its own timestamp at the instant the rising edge of this pulse signal arrives. By calculating the difference between this timestamp and the standard second boundary represented by the 1PPS second pulse signal, a precise local clock offset is obtained. , in, This represents the local clock offset that needs to be calibrated; This represents the timestamp recorded by the local clock source when the rising edge of the second pulse signal 1PPS arrives. This value is obtained directly from the counter of the local clock source through a hardware interrupt or time capture unit. This represents the Coordinated Universal Time (UTC) second boundary corresponding to the 1PPS of the second pulse signal, as pre-announced by the serial time message. After obtaining the local clock offset, a software-implemented phase-locked loop (PLL) or frequency-locked loop (FLL) algorithm continuously fine-tunes the operating frequency of the local clock source or dynamically adjusts the count value of the local time counter, aiming to bring the local clock offset obtained in subsequent measurements close to zero. This closed-loop control process of continuous comparison, calculation, and adjustment ultimately ensures that the time output by the local clock source is highly synchronized with the BeiDou satellite time. This precisely calibrated and continuously locked local time constitutes the standard time reference for the entire measurement device.

[0025] The system continuously monitors the real-time status of BeiDou satellite signals, generates signal quality parameters, and generates a dynamic compensation mode trigger signal when the signal quality parameters are lower than a preset quality threshold. In response to the dynamic compensation mode trigger signal, the clock operating environment parameters of the local clock source are collected, and the drift characteristics are predicted by combining the standard time base with the clock operating environment parameters to generate a short-term clock offset prediction value. A set of adjacent nodes is determined based on the topology connection relationship of the distribution network, and a time synchronization request is sent to the set of adjacent nodes to obtain the timestamps of the adjacent nodes. The theoretical time difference is then calculated by combining the line physical parameters contained in the topology connection relationship of the distribution network, and the timestamps of the adjacent nodes are corrected using the theoretical time difference to generate the topology correction amount. By fusing the short-term clock offset prediction value with the topology correction amount, a dynamic compensation time base is generated; Electrical quantity measurement data of the distribution network is collected, and the electrical quantity measurement data is time-stamped using the dynamic compensation time base to generate time-stamped synchronous measurement data.

[0026] Optionally, the dynamic compensation mode trigger signal includes: The number of satellites receiving the BeiDou satellite signals, the signal-to-noise ratio, and the position accuracy factor are collected to form the raw state data; The original state data is weighted and comprehensively evaluated to generate the signal quality parameters; Obtain the critical performance index used to characterize the transition of a signal from reliable to unreliable, and generate a quality threshold. When the signal quality parameter is lower than the preset quality threshold, a dynamic compensation mode trigger signal is generated.

[0027] Specifically, to accurately assess the reliability of BeiDou satellite timing signals and generate dynamic compensation mode trigger signals, it is first necessary to collect a series of raw state data reflecting signal quality in real time from the BeiDou timing receiver. These data primarily include the number of received satellites, the signal-to-noise ratio (SNR), and the position accuracy factor. The number of received satellites refers to the number of satellites that can be effectively tracked and used for calculation; the SNR is an indicator that measures the relative strength of the received satellite signal to the background noise level, directly affecting the accuracy of information decoding; and the position accuracy factor is a dimensionless value characterizing the geometric configuration of satellites in orbit—a smaller value indicates a more ideal satellite distribution and higher timing and positioning accuracy. These three sets of raw state data together constitute a comprehensive description of the current BeiDou signal state. A weighted comprehensive evaluation is then performed on these raw state data to generate a single signal quality parameter. , in, These are the final signal quality parameters. , and These are preset weighting coefficients corresponding to the number of received satellites, signal-to-noise ratio, and position accuracy factor, respectively. Their sum is 1, and their specific values ​​are determined based on experimental data or expert experience, reflecting the relative importance of each factor to the timing accuracy. The normalization function maps raw state data with different dimensions to a unified dimensionless interval for weighted summation. For example, for better values ​​in the number of receiving satellites and signal-to-noise ratio, the normalization function maps them to larger values; conversely, for better values ​​in the position accuracy factor, the normalization function performs the opposite process, mapping it to a larger value as well. Next, a quality threshold needs to be obtained, which is a critical performance indicator characterizing the transition of a reliable signal to an unreliable one. This quality threshold is determined by comparing the real-time calculated signal quality parameters with the actual timing error measured by a high-precision time reference source under different signal conditions. The value corresponding to the timing error exceeding the allowable range for distribution network applications is then set as the preset quality threshold. During operation, the current signal quality parameters are continuously calculated and compared with this preset quality threshold. Once the signal quality parameters are found to be lower than the preset quality threshold, the reliability of the BeiDou signal is immediately determined to be insufficient, and a dynamic compensation mode trigger signal is immediately generated. This signal will activate the subsequent internal clock drift prediction and topology cooperative timing mechanism to ensure that the measurement device can still provide a high-precision synchronization time reference even when the satellite signal is poor.

[0028] Optionally, the step of collecting the clock operating environment parameters of the local clock source and combining them with the standard time base to predict drift characteristics and generate short-term clock offset prediction values ​​includes: The real-time operating temperature and power supply voltage of the local clock source are obtained to form the clock operating environment parameters; Establish a drift characteristic prediction model to describe the correspondence between clock frequency drift and the clock operating environment parameters; The clock operating environment parameters collected in real time are input into the drift characteristic prediction model. Combined with the standard time base as the initial state, the short-term clock offset prediction value is calculated and output.

[0029] Specifically, upon responding to the dynamic compensation mode trigger signal, to generate short-term clock offset prediction values, the system first initiates precise sensing of the local clock source's operating status. Through temperature sensors deployed in the physical enclosure of the local clock source and a voltage monitoring unit built into the power supply circuit, the system collects the current operating temperature and power supply voltage in real time and periodically. These two physical quantities together constitute the clock's operating environment parameters. Simultaneously, a pre-established drift characteristic prediction model is invoked. This model has been trained offline and internally establishes the nonlinear correspondence between the frequency drift of the specific local clock source and its clock operating environment parameters. At the start of the prediction calculation, i.e., the instant the dynamic compensation mode trigger signal is received, the current standard time reference is used as the initial, unbiased state. Subsequently, the real-time collected clock operating environment parameters are continuously fed into the drift characteristic prediction model. Based on the input environmental parameters, the model calculates in real time the normalized frequency drift of the local clock source relative to its ideal rated frequency under the current operating conditions. This instantaneous frequency drift is integrated over a small time step and accumulated from the initial state to calculate the total time offset accumulated since the moment the BeiDou satellite signal was lost. This accumulated time deviation is the short-term clock offset prediction, and its generation process can be expressed by the following formula: , in, This is the output short-term clock offset prediction. (Summarization symbol) This means that the drift amount calculated for each sampling period is accumulated starting from the moment the dynamic compensation mode is triggered. It is the normalized frequency drift output by the drift characteristic prediction model in the i-th sampling period, which is determined by the real-time operating temperature collected during that period. and power supply voltage The only certainty is that it is a dimensionless quantity. It is a fixed time step for collecting environmental parameters and performing model calculations. In this way, the timing error of the local clock source can be dynamically predicted based on real-time perception of the local physical environment.

[0030] Optionally, the step of establishing a drift characteristic prediction model to describe the correspondence between clock frequency drift and the clock operating environment parameters includes: When the signal quality parameter is greater than the quality threshold, the clock operating environment parameters under different operating conditions are continuously recorded; By continuously comparing the actual time of the local clock source with the standard time reference, the actual clock drift data corresponding to the clock operating environment parameters is obtained; Based on the multivariate correspondence between the clock operating environment parameters and the actual clock drift data, a drift characteristic prediction model is generated by training through fitting or machine learning methods.

[0031] Specifically, to establish a drift characteristic prediction model describing the correspondence between the local clock source frequency drift and clock operating environment parameters, this method first performs an offline learning and modeling process. This process is conducted under the condition that the BeiDou satellite signal quality parameters are consistently higher than a preset quality threshold, i.e., the timing signal is absolutely reliable. During this period, a standard time reference generated by high-precision BeiDou satellite signal calibration is used as the truth reference. The real-time operating temperature and power supply voltage of the local clock source are continuously collected through built-in high-precision sensors; these parameters constitute the clock operating environment parameters reflecting the current operating status. To build a comprehensive model, this data acquisition process needs to be extensively conducted under various operating conditions that the measuring device may experience, covering a wide range of temperature and voltage variations. While collecting environmental parameters, the actual time output by the local clock source is continuously and precisely compared with the standard time reference, thereby accurately quantifying the actual clock drift data caused by environmental changes. The actual clock drift data, i.e., the frequency drift of the local clock source, can be calculated in the following way: , in, It represents the actual frequency drift measured over a very short time interval and is a dimensionless ratio. and In real physical time and Time readings recorded by a local clock source. and This refers to the precise time provided by a standard time base at the same physical point in time. Through such differential calculations, accurate actual clock drift data corresponding to specific clock operating environment parameters can be obtained. After long-term operation, a large dataset of multivariate correspondences between clock operating environment parameters and actual clock drift data has been accumulated. Based on this dataset, multivariate regression fitting analysis or machine learning methods such as support vector machines and neural networks are used for training, ultimately generating a fixed drift characteristic prediction model. This model can accurately output the corresponding clock frequency drift prediction value using newly acquired clock operating environment parameters as input.

[0032] Optionally, the generated topology correction includes: Determine the set of topologically adjacent nodes based on the topological connection relationship of the distribution network, and send a time synchronization request to the set of topologically adjacent nodes to obtain the timestamps of the adjacent nodes; The physical parameters of the lines are extracted from the topology of the power distribution network, and the theoretical time difference of signal propagation between nodes is calculated based on the physical parameters of the lines. The measurement time difference is obtained by calculating the timestamps of the received adjacent nodes and the time when the local time synchronization request was sent. The theoretical time difference and network communication delay are subtracted from the measured time difference to generate the topology correction.

[0033] Specifically, to generate the topology correction, firstly, based on the stored distribution network topology connections, all nodes directly connected to the current measurement node on the physical line are queried and identified, forming a set of topologically adjacent nodes. Next, the timestamps of their respective adjacent nodes are obtained. Simultaneously, the physical parameters of the lines connecting this node to each adjacent node, especially the precise length of the lines, are extracted from the distribution network topology connection data. Based on these physical parameters, the theoretical time difference required for a signal to propagate along the power line between two nodes can be calculated. The theoretical time difference is a time quantity determined by physical distance and the propagation medium. Subsequently, the timestamps of adjacent nodes received from them are compared with the local timestamp recorded by the local node when sending the corresponding time synchronization request, calculating the original difference between the two, i.e., the measurement time difference. This measurement time difference incorporates the actual clock bias, physical propagation delay, and communication system delay. Finally, to separate the pure clock bias, i.e., to generate the topology correction, the theoretical time difference and network communication delay are subtracted from the measurement time difference. , in, It is the final generated topology correction, which directly reflects the deviation of the local clock relative to the average clock of neighboring nodes. It is the timestamp of the adjacent node obtained. It is the timestamp of the local node itself when it initiates a time synchronization request, provided by the local clock source. It is the theoretical time difference, which is obtained by dividing the physical length of the line L by the signal propagation speed v. L is extracted from the topology of the distribution network, and v is a known physical constant. This refers to network communication latency, representing a fixed processing time within a node, obtained through offline calibration. Through this series of operations, the combined clock information of adjacent nodes can be effectively converted into a precise correction value for the local clock, thereby achieving distributed peer-to-peer time synchronization within the region even in environments without satellite signals.

[0034] Optionally, sending a time synchronization request to the set of neighboring nodes in the topology to obtain the timestamps of neighboring nodes includes: Send a time synchronization request to the set of adjacent nodes in the topology, and receive multiple timestamps from adjacent nodes to form an initial timestamp group; Evaluate the consistency and validity of each timestamp in the initial timestamp group, remove outliers or abnormal values, and generate an optimal timestamp group; The timestamps in the preferred timestamp group are averaged or weighted to generate timestamps for adjacent nodes.

[0035] Specifically, to accurately obtain the timestamps of neighboring nodes for time synchronization comparison, this method first sends a time synchronization request to all nodes within the determined set of topologically adjacent nodes via the communication network. In response, each topologically adjacent node returns its current time information, and these time data returned by multiple different nodes constitute the initial timestamp set. Due to potential jitter in network transmission or temporary large deviations in the clocks of individual neighboring nodes, the data in the initial timestamp set may not be completely consistent or reliable. Therefore, the initial timestamp set must be screened to improve the accuracy of the final reference time. The screening process involves evaluating the consistency and validity of each timestamp in the initial timestamp set. This step can employ statistical methods, such as calculating the mean and standard deviation of the timestamp set. Based on these statistics, a reasonable confidence interval is set, and any values ​​outside this interval are identified as outliers. These outliers, either due to excessive latency caused by network anomalies or significant deviations from the group due to source node clock failures, should be considered as outliers and removed from the initial timestamp set. Through this removal step, a superior timestamp set with higher data quality and better consistency is obtained. Finally, to generate a unique and representative neighboring node timestamp from the preferred timestamp group, the remaining valid timestamps within the group need to be merged. The most direct method is to perform an arithmetic average, which involves adding all the timestamp values ​​in the preferred timestamp group and dividing by the number of timestamps to obtain an average value. A more sophisticated strategy can use a weighted average. The weights here can be based on the reliability information of each neighboring node's timestamp source, such as the quality of the node's own BeiDou signal or its synchronization consistency with other nodes. By averaging or weighted averaging the preferred timestamp group, a robust and accurate neighboring node timestamp is finally generated, which integrates the time information of multiple reliable nodes within the region.

[0036] Optionally, the step of fusing the short-term clock offset prediction value with the topology correction amount to generate a dynamic compensation time base includes: While acquiring the timestamps of the adjacent nodes, a node time synchronization quality index representing the time synchronization status of the source node of the adjacent node timestamp is acquired. When the node timing quality index of a topologically adjacent node is higher than the preset autonomous operation threshold, a dynamic fusion weight is generated based on the node timing quality index to adjust the confidence level of the topology correction amount and the short-term clock offset prediction value. Using the dynamic fusion weights, the short-term clock offset prediction value and the topology correction amount are weighted and summed to generate a dynamic compensation time base.

[0037] Specifically, when BeiDou satellite signals become unreliable and dynamic compensation mode is entered, two different time correction information needs to be intelligently fused to generate an accurate dynamic compensation time reference: short-term clock offset predictions based on local physical environment awareness and topology corrections based on network collaboration. This fusion process is not a simple addition, but rather employs an adaptive dynamic weighting strategy. Its core lies in evaluating and utilizing the time synchronization reliability of topologically adjacent nodes. Specifically, when the local node sends a time synchronization request to the set of topologically adjacent nodes and obtains the timestamps of the adjacent nodes, in addition to the timestamps themselves, it must also synchronously acquire a key parameter: the node time synchronization quality index. The node time synchronization quality index is a quantifiable value that characterizes the current state and reliability of the time synchronization provided by the adjacent node that gave the timestamp. For example, this index can comprehensively reflect whether the adjacent node is receiving high-quality BeiDou satellite signals or the stability of its internal clock. This index is sent to the local node by the adjacent nodes when replying to the time synchronization request.

[0038] Next, the node timing quality metrics of each topologically adjacent node need to be compared with a preset autonomous operation threshold. The autonomous operation threshold is a pre-defined critical value used to determine whether the time reference of a neighboring node is sufficiently reliable and can serve as a timing reference within the region. If at least one node in the set of topologically adjacent nodes has a node timing quality metric significantly higher than this autonomous operation threshold, this indicates the existence of one or more "master" nodes with excellent timing quality in the network. At this point, a pair of dynamic fusion weights will be generated based on these node timing quality metrics that are above the threshold. A higher node timing quality metric means more reliable time information, thus assigning a higher weight to the topology correction amount, while correspondingly reducing the weight of the locally self-predicted short-term clock offset prediction value.

[0039] Finally, using this pair of dynamic fusion weights, the short-term clock offset prediction and topology correction are weighted and summed to calculate the final dynamic compensation time base: , in, It is the generated dynamic compensation time base, representing the total amount of correction to the local clock. and These are the dynamic fusion weights for the short-term clock offset prediction and the topology correction, respectively. They are dimensionless confidence coefficients, and their sum is 1. It is the clock offset predicted by the local clock source based on its own environmental parameters, that is, the short-term clock offset prediction value. The clock offset correction is calculated by comparing the clock times with those of adjacent nodes in the topology; this is known as the topology correction. This refined adaptive fusion mechanism enables the generation of a more robust and accurate dynamically compensated time reference.

[0040] Optionally, the method further includes: When the node timing quality index of all topological adjacent nodes is lower than the autonomous operation threshold, the timestamps of adjacent nodes of all nodes in the topological adjacent node set are obtained to form a regional timestamp set. Using the dispersion of the timestamps of adjacent nodes within the set of timestamps in the region, and with the goal of minimizing the dispersion, an objective optimization function is established using the dispersion of the timestamps of adjacent nodes within the set of timestamps in the region, and the topology correction amount corresponding to minimizing the dispersion is obtained by solving the problem. Update the current topology correction using the topology correction corresponding to minimizing the dispersion.

[0041] Specifically, when the timing quality index of all adjacent nodes in the topology is lower than the preset autonomous operation threshold, it indicates that all measurement nodes in the entire region have lost a reliable external time source, such as BeiDou satellite signals, and cannot find a node with significantly better timing quality as the dominant reference. In this peer-to-peer autonomous operation mode, the goal of time synchronization shifts from pursuing absolute time accuracy to maintaining the relative consistency of time among all nodes in the region. To this end, an optimization strategy aimed at minimizing regional time dispersion will be adopted to generate topology correction quantities.

[0042] Specifically, the node first needs to proactively initiate a full-scale time information exchange with its entire set of neighboring nodes in the topology. This is not only to obtain the timestamps of each neighboring node, but more importantly, through this exchange, each node can learn the timestamps of all its neighbors. In this way, the node can construct a regional timestamp set. This regional timestamp set includes the timestamps of the node itself, as well as the timestamps of the neighboring nodes of all its topological neighbors, essentially aggregating the clock information of all nodes in the vicinity of the node centered on it.

[0043] Next, we calculate the dispersion within the timestamp set of the region under the current state. Dispersion is a statistical metric used to quantify the degree to which a set of data points deviates from its central value; commonly used metrics are variance or standard deviation. To calculate dispersion, we first need to calculate the average of all timestamps in the region's timestamp set, then calculate the sum of squared differences between each timestamp and this average, and finally calculate the average of these differences, i.e., the variance. Afterward, an optimization calculation process begins, aiming to find an optimal topology correction. This topology correction, applied to the clock of this node, minimizes the dispersion of the new set formed by the corrected timestamps of this node and the timestamps of other nodes within the region. In other words, we find a correction value. This ensures that, after applying the correction, the time signature across the entire region achieves maximum consistency. This process can be expressed as minimizing the objective function: , in, This represents the operation of finding the minimum value. It is the variance of the set of regional timestamps, i.e., the dispersion. These are the timestamps of other nodes within the region, and these values ​​are obtained from the region's timestamp set. This is the current, uncorrected time for this node. This is the topology correction quantity that is to be found, which minimizes the time dispersion of the entire region. By solving this optimization problem, we obtain... This is the final output topology correction, which aligns the time of this node with the overall "center" of the regional time. This topology correction is used to calculate the dynamic compensation time base.

[0044] Optionally, after generating the dynamic compensation time base, the method further includes: Continue to monitor the real-time status of the BeiDou satellite signals and update the signal quality parameters; Determine whether the updated signal quality parameters within a preset time window are lower than the quality threshold. If not, the use of the dynamic compensation time reference will be terminated, and the calibration of the local clock source based on the BeiDou satellite signal will be re-executed to obtain the updated standard time reference; The electrical quantity measurement data are time-stamped using the updated standard time base.

[0045] Specifically, after switching to dynamic compensation mode due to poor BeiDou satellite signal quality and starting to use the dynamic compensation time base for time stamping electrical quantity measurement data, the monitoring of external signals will not be terminated. Instead, a continuous, dynamic recovery monitoring and switching mechanism will be initiated to ensure that once external timing conditions improve, the system can quickly return to the optimal synchronization state. Specifically, even in dynamic compensation mode, the signal quality monitoring module continues to run uninterrupted in the background, continuously collecting and processing the raw state data of the BeiDou satellite signal to update signal quality parameters in real time. This process is completely consistent with the monitoring behavior before triggering dynamic compensation mode. Next, a preset time window is introduced, defining an observation period for judging whether the signal quality has stably recovered. Within this time window, it will continuously judge whether each newly generated signal quality parameter has risen above the preset quality threshold. The key point of this step is that it does not immediately switch based on a single rise in signal quality parameters, but requires the signal quality to remain stable and reliable for a continuous period of time. If, within the entire preset time window, all updated signal quality parameters fail to consistently exceed the quality threshold, it will be determined that the BeiDou satellite signal has not yet been restored, and the current dynamic compensation mode will continue to be maintained, using the dynamic compensation time reference to time-stamp the electrical quantity measurement data. Conversely, if it is detected that within the current preset time window, the updated signal quality parameters are consistently and consistently higher than the preset quality threshold, this indicates that the BeiDou satellite signal timing conditions have recovered from an unreliable state to a high-quality state. The conditions for exiting the dynamic compensation mode will be determined to be met, and the use of the dynamic compensation time reference generated by internal prediction and topology collaboration will be immediately terminated. Following this, the initial BeiDou calibration process will be re-executed, i.e., using the current high-quality BeiDou satellite signal to perform a completely new and precise calibration of the local clock source, eliminating any minor errors that may have accumulated during dynamic compensation, and generating an updated standard time reference highly synchronized with Coordinated Universal Time (UTC). After obtaining this updated standard time reference, a seamless switch will occur, and this most accurate standard time reference will immediately begin to be used to time-stamp subsequently acquired distribution network electrical quantity measurement data.

[0046] Based on the same inventive concept, the present invention also provides a distributed measurement synchronization device for power distribution networks based on BeiDou satellite timing, the device comprising: The BeiDou calibration module is used to acquire BeiDou satellite signals and calibrate the local clock source based on the BeiDou satellite signals to generate a standard time reference. The signal quality monitoring module is used to continuously monitor the real-time status of BeiDou satellite signals, generate signal quality parameters, and generate a dynamic compensation mode trigger signal when the signal quality parameters are lower than a preset quality threshold. The drift characteristic prediction module is used to respond to the dynamic compensation mode trigger signal, collect the clock operating environment parameters of the local clock source, and combine the standard time base with the clock operating environment parameters to predict the drift characteristics and generate a short-term clock offset prediction value. The topology information interaction module is used to determine the set of adjacent nodes based on the distribution network topology connection relationship, send a time synchronization request to the set of adjacent nodes to obtain the timestamps of the adjacent nodes, calculate the theoretical time difference in combination with the line physical parameters contained in the distribution network topology connection relationship, and use the theoretical time difference to correct the timestamps of the adjacent nodes to generate a topology correction amount. The time base fusion module is used to fuse the short-term clock offset prediction value with the topology correction amount to generate a dynamically compensated time base. The timestamp generation module is used to collect electrical quantity measurement data of the distribution network and use the dynamic compensation time base to time-stamp the electrical quantity measurement data to generate synchronous measurement data with timestamps.

[0047] To verify the feasibility and effectiveness of this invention in practical applications, it was applied to a distributed synchronous measurement project in a regional power distribution network. This project aims to achieve high-precision synchronous acquisition of electrical quantities such as voltage and current across the entire network by deploying high-precision synchronous measurement devices at multiple power distribution network nodes, such as distributed power source access points, smart switches, and distribution terminal units (DTUs). This supports advanced power distribution automation applications, such as precise fault location, state estimation, and renewable energy consumption analysis.

[0048] The synchronization method and apparatus of this invention are integrated and deployed in a 10kV simulated power distribution network environment containing 20 nodes. This network environment simulates a complex scenario common in cities, with a mix of overhead and cable lines and building obstructions, to test the synchronization performance of the apparatus under ideal and non-ideal BeiDou satellite signal conditions.

[0049] In this embodiment, each power distribution terminal unit equipped with the device of this invention first acquires BeiDou satellite signals through its built-in BeiDou calibration module. The BeiDou time receiver within this module decodes the serial time message and a high-precision pulse-of-seconds (1PPS) signal from the satellite signal. The serial time message provides year, month, day, hour, minute, and second information. By aligning the serial message with an internal clock counter and utilizing the precise rising edge of the 1PPS signal to trigger hardware time capture, the device calculates the precise offset between the local clock source (temperature compensated crystal oscillator, TCXO) and standard UTC time. Subsequently, a software phase-locked loop algorithm is used to continuously fine-tune the local clock to achieve high synchronization with BeiDou time, generating a standard time reference. Under good BeiDou signal conditions, the synchronization accuracy of each node is measured to be better than 100 nanoseconds, fully meeting the requirements for power distribution network synchronization phasor measurement.

[0050] To verify the effectiveness of the dynamic compensation mechanism, a scenario of BeiDou signal loss was artificially simulated in the experiment, such as using a GPS signal jammer or placing the device deep inside a building. The signal quality monitoring module continuously evaluated parameters such as the number of received satellites, signal-to-noise ratio (SNR), and position accuracy factor (PDOP). The experiment was set so that when the weighted comprehensive evaluation of signal quality parameters fell below a preset threshold of 0.6, the device automatically generated a dynamic compensation mode trigger signal. The preset threshold of 0.6 corresponds to the critical point where the synchronization error may exceed 1 microsecond.

[0051] Once the dynamic compensation mode is entered, the drift characteristic prediction module is immediately activated. This module first calls a pre-trained drift characteristic prediction model, which was built by recording actual drift data of the local clock under different operating temperatures and supply voltages when the BeiDou signal is good. After signal loss, the module inputs real-time collected local clock operating environment parameters, such as temperature rising from 25℃ to 40℃, into the prediction model to calculate the short-term clock offset prediction value. Data shows that in the first 30 minutes without any external reference, compensation based solely on this prediction value controls the clock drift error to within 5 microseconds, a significant improvement compared to no compensation.

[0052] Simultaneously, the topology information interaction module is activated. Based on a pre-stored distribution network topology map, the device sends time synchronization requests to directly connected adjacent nodes, such as upstream switches and downstream DTUs. Through multiple requests and responses, a reliable timestamp of an adjacent node, after outlier removal, is obtained. If a node requests time from its three adjacent nodes after losing its BeiDou signal, and one of these adjacent nodes still receives a good BeiDou signal, its timestamp is assigned higher weight. The device, combining the physical parameters of the line (500 meters in length), calculates a theoretical propagation delay of approximately 2.5 microseconds, and then calculates the topology correction.

[0053] The time base fusion module dynamically weights and fuses the two correction values ​​mentioned above. In the scenario described, since a neighboring node can still provide high-quality BeiDou timing (i.e., its timing quality index is higher than the preset autonomous operation threshold), the device assigns a higher weight of 0.7 to the topology correction value and a weight of 0.3 to the local short-term clock offset prediction value. The dynamically compensated time base generated after fusion ensures that the node's synchronization error remains within 2 microseconds during a signal loss period of up to one hour, far superior to the effect of relying on either compensation method alone.

[0054] In another test, a regional BeiDou signal interruption was simulated, where the timing quality indicators of all adjacent nodes fell below the autonomous operation threshold. At this point, the device switched to a fully autonomous operation mode. Each node aimed to minimize regional time dispersion and calculated topology corrections using optimization algorithms, achieving a high degree of relative consistency in time among all nodes within the region. Experimental results show that although there is a slight drift in absolute time, the synchronization error between any two nodes within the region remains within 5 microseconds, effectively ensuring the accuracy of applications such as fault location based on phase difference calculations.

[0055] Once the external signal interference was resolved, the signal quality monitoring module detected that the signal quality parameter remained stable above 0.8 for 5 consecutive minutes, and the device determined that the BeiDou signal had been restored. It then automatically exited the dynamic compensation mode and re-executed the BeiDou signal calibration process, seamlessly aligning the local clock with the standard time.

[0056] Table 1 Comparison of node time errors under different synchronization modes

[0057] Table 2 Device Mode Switching Response Time Data Table

[0058] To more intuitively demonstrate the technical effects of the present invention, such as Figure 3 As shown in Tables 1 and 2, the variation of node time error with signal loss time under different synchronization modes is compared. The data in Tables 1 and 2 demonstrate that the method and apparatus of this invention, when the BeiDou satellite signal is unreliable or completely interrupted, can significantly improve synchronization accuracy and device robustness through a dynamic compensation mechanism combining internal clock drift prediction and external topology-coordinated timing. Compared to the uncompensated free-running mode, this invention reduces the synchronization error from hundreds of microseconds to less than 5 microseconds, which can last up to one hour, ensuring the normal operation of advanced power distribution network applications.

[0059] It should be noted that the electrical connections between the various units described above do not necessarily represent direct or indirect connections. Any indirect connection method can be applied to the embodiments of the present invention as long as it achieves the purpose of the present invention. The above descriptions are merely exemplary embodiments of the present invention and should not be construed as limiting the scope of the present invention.

[0060] All equivalent changes and modifications made in accordance with the teachings of this invention are still within the scope of this invention. Those skilled in the art will readily conceive of other embodiments of this invention upon considering the specification and the disclosure of practical truth. This application is intended to cover any variations, uses, or adaptations of this invention that follow the general principles of this invention and include common knowledge or conventional techniques in the art not described herein.

Claims

1. A distributed measurement synchronization method for power distribution networks based on BeiDou satellite timing, characterized in that, The method includes: Acquire BeiDou satellite signals and calibrate the local clock source based on the BeiDou satellite signals to generate a standard time reference; Continuously monitor the real-time status of BeiDou satellite signals, generate signal quality parameters, and when the signal quality parameters are lower than a preset quality threshold, generate a dynamic compensation mode trigger signal, including: The number of satellites receiving the BeiDou satellite signals, the signal-to-noise ratio, and the position accuracy factor are collected to form the raw state data; The original state data is weighted and comprehensively evaluated to generate the signal quality parameters: ； in, These are the final signal quality parameters; , and These correspond to the number of satellites received. Signal-to-noise ratio and position accuracy factor The preset weighting coefficients; Represents the normalization function; Obtain the critical performance index used to characterize the transition of a signal from reliable to unreliable, and generate a quality threshold. When the signal quality parameter is lower than the preset quality threshold, a dynamic compensation mode trigger signal is generated. In response to the dynamic compensation mode trigger signal, the clock operating environment parameters of the local clock source are acquired, and drift characteristics are predicted by combining the standard time base with the clock operating environment parameters to generate a short-term clock offset prediction value, including: The real-time operating temperature and power supply voltage of the local clock source are obtained to form the clock operating environment parameters; A drift characteristic prediction model is established to describe the correspondence between clock frequency drift and the clock operating environment parameters, including: When the signal quality parameter is greater than the quality threshold, the clock operating environment parameters under different operating conditions are continuously recorded; By continuously comparing the actual time of the local clock source with the standard time reference, the actual clock drift data corresponding to the clock operating environment parameters is obtained; Based on the multivariate correspondence between the clock operating environment parameters and the actual clock drift data, a drift characteristic prediction model is generated through training using fitting or machine learning methods. The method is as follows: The actual clock drift data, i.e., the frequency drift of the local clock source, is calculated in the following way: ； in, It represents the actual frequency drift measured over a very short time interval and is a dimensionless ratio; and In real physical time and Time readings recorded by a local clock source; and It is the precise time provided by a standard time reference at the same physical point in time; Based on the dataset of multiple correspondences between accumulated clock operating environment parameters and actual clock drift data, a fixed drift characteristic prediction model is generated by training using multiple regression fitting analysis. The real-time collected clock operating environment parameters are input into the drift characteristic prediction model, and the short-term clock offset prediction value is calculated and output using the standard time base as the initial state: ； in, It is the output short-term clock offset prediction value; This means that the drift amount calculated for each sampling period is accumulated starting from the moment the dynamic compensation mode is triggered; It is the normalized frequency drift output by the drift characteristic prediction model in the i-th sampling period, which is determined by the real-time operating temperature collected during that period. and power supply voltage The only certainty is that it is a dimensionless quantity; It is a fixed time step for environmental parameter acquisition and model calculation; Based on the distribution network topology connections, a set of adjacent nodes is determined, and a time synchronization request is sent to this set to obtain the timestamps of the adjacent nodes. Then, the theoretical time difference is calculated using the line physical parameters included in the distribution network topology connections. This theoretical time difference is then used to correct the timestamps of the adjacent nodes, generating a topology correction amount, including: Determine the set of topologically adjacent nodes based on the topological connection relationship of the distribution network, and send a time synchronization request to the set of topologically adjacent nodes to obtain the timestamps of the adjacent nodes; The physical parameters of the lines are extracted from the topology of the power distribution network, and the theoretical time difference of signal propagation between nodes is calculated based on the physical parameters of the lines. The measurement time difference is obtained by calculating the timestamps of the received adjacent nodes and the time when the local time synchronization request was sent. Subtract the theoretical time difference and network communication delay from the measured time difference to generate the topology correction: ； in, This is the final generated topology correction amount; These are the timestamps of the adjacent nodes that have been obtained; It is the timestamp of the local node itself when it initiates a time synchronization request, provided by the local clock source; It is the theoretical time difference, obtained by dividing the physical length of the line L by the signal propagation speed v; It represents network communication latency, a fixed processing time within a node, obtained through offline calibration; By fusing the short-term clock offset prediction with the topology correction, a dynamic compensation time base is generated, including: While acquiring the timestamps of the adjacent nodes, a node time synchronization quality index representing the time synchronization status of the source node of the adjacent node timestamp is acquired. When the node timing quality index of a topologically adjacent node is higher than the preset autonomous operation threshold, a dynamic fusion weight is generated based on the node timing quality index to adjust the confidence level of the topology correction amount and the short-term clock offset prediction value. Using the dynamic fusion weights, the short-term clock offset prediction and the topology correction are weighted and summed to generate the dynamic compensation time base: ； in, It is the generated dynamic compensation time base, representing the total amount of correction to the local clock; and These are the dynamic fusion weights for short-term clock offset predictions and topology corrections, respectively. It is the clock offset predicted by the local clock source based on its own environmental parameters, that is, the short-term clock offset prediction value; It is the clock offset correction amount calculated by comparing the time with the time of adjacent nodes in the topology, i.e., the topology correction amount; When the node timing quality index of all topological adjacent nodes is lower than the autonomous operation threshold, the timestamps of adjacent nodes of all nodes in the topological adjacent node set are obtained to form a regional timestamp set. Using the dispersion of the timestamps of adjacent nodes within the aforementioned regional timestamp set, and with the goal of minimizing this dispersion, an objective optimization function is established using the dispersion of the timestamps of adjacent nodes within the aforementioned regional timestamp set. Solving for this function yields the topology correction amount corresponding to the minimized dispersion. This process is described as minimizing the objective function: ； in, It is the variance of the set of timestamps in the region, i.e., the dispersion; These are the timestamps of other nodes within the region, obtained from the region's timestamp set; This is the current, unmodified time of this node; It is the topological correction quantity that is to be found, which minimizes the time dispersion of the entire region; By solving the objective function, we obtain This is the final output topology correction amount; Update the current topology correction using the topology correction corresponding to minimizing the dispersion; Electrical quantity measurement data of the distribution network is collected, and the electrical quantity measurement data is time-stamped using the dynamic compensation time base to generate time-stamped synchronous measurement data.

2. The distributed measurement synchronization method for power distribution networks based on BeiDou satellite timing as described in claim 1, characterized in that, Sending a time synchronization request to the set of neighboring nodes in the topology to obtain the timestamps of neighboring nodes includes: Send a time synchronization request to the set of adjacent nodes in the topology, and receive multiple timestamps from adjacent nodes to form an initial timestamp group; The consistency and validity of each timestamp in the initial timestamp group are evaluated, outliers or abnormal values ​​are removed, and an optimal timestamp group is generated. The timestamps in the preferred timestamp group are averaged or weighted to generate timestamps for adjacent nodes.

3. The distributed measurement synchronization method for distribution networks based on BeiDou satellite timing as described in claim 1, characterized in that, After generating the dynamic compensation time base, the following is also included: Continue to monitor the real-time status of the BeiDou satellite signals and update the signal quality parameters; Determine whether the updated signal quality parameters within a preset time window are lower than the quality threshold. If not, the use of the dynamic compensation time reference will be terminated, and the calibration of the local clock source based on the BeiDou satellite signal will be re-executed to obtain the updated standard time reference; The electrical quantity measurement data are time-stamped using the updated standard time base.

4. A distributed measurement synchronization device for distribution networks based on BeiDou satellite timing, applied to the distributed measurement synchronization method for distribution networks based on BeiDou satellite timing as described in any one of claims 1-3, characterized in that, The device includes: The BeiDou calibration module is used to acquire BeiDou satellite signals and calibrate the local clock source based on the BeiDou satellite signals to generate a standard time reference. The signal quality monitoring module is used to continuously monitor the real-time status of BeiDou satellite signals, generate signal quality parameters, and generate a dynamic compensation mode trigger signal when the signal quality parameters are lower than a preset quality threshold. The drift characteristic prediction module is used to respond to the dynamic compensation mode trigger signal, collect the clock operating environment parameters of the local clock source, and combine the standard time base with the clock operating environment parameters to predict the drift characteristics and generate a short-term clock offset prediction value. The topology information interaction module is used to determine the set of adjacent nodes based on the distribution network topology connection relationship, send a time synchronization request to the set of adjacent nodes to obtain the timestamps of the adjacent nodes, calculate the theoretical time difference in combination with the line physical parameters contained in the distribution network topology connection relationship, and use the theoretical time difference to correct the timestamps of the adjacent nodes to generate a topology correction amount. The time base fusion module is used to fuse the short-term clock offset prediction value with the topology correction amount to generate a dynamically compensated time base. The timestamp generation module is used to collect electrical quantity measurement data of the distribution network and use the dynamic compensation time base to time-stamp the electrical quantity measurement data to generate synchronous measurement data with timestamps.

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