High-precision monitoring method and system for partial discharge current pulse signal

Abstract

The invention relates to the technical field of discharge monitoring, and provides a high-precision monitoring method and system for partial discharge current pulse signals. The method comprises the following steps: activating distributed broadband monitoring equipment to continuously monitor a transformer to obtain distributed monitoring information; extracting first monitoring information, and performing feature collection on the first pulse signal to obtain a pulse feature set; establishing a multi-conductor transmission line model based on the multi-dimensional characteristic parameters of the transformer, and performing simulation to obtain simulation information; and calling a partial discharge positioning strategy to analyze the pulse feature set and the simulation information, and determining the partial discharge source of the transformer. According to the invention, the technical problems that the partial discharge pulse signal in the transformer cannot be accurately extracted and analyzed and the accurate positioning of the partial discharge source is influenced because the detection blind area is easily influenced by electromagnetic interference and the weak signal identification is insufficient in the existing partial discharge monitoring method are solved; the technical effect of high-precision partial discharge source positioning is achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of discharge monitoring, in particular to a high-precision monitoring method and system for partial discharge current pulse signals. BACKGROUND

[0002] Partial discharge (PD) refers to a phenomenon that an electric field with excessively high intensity is formed in a local area due to defects or aging of insulation materials in an electrical device. The partial discharge is not only a precursor of a fault of the electrical device, but also can accelerate aging of insulation materials of the device, and can even cause damage to the device and even cause a safety accident. Therefore, monitoring and positioning of the partial discharge are of great significance, especially for partial discharge monitoring of high-voltage devices such as transformers. At present, the detection methods for the partial discharge mainly include a current method, an acoustic wave method, an ultrasonic wave method and the like, but these methods usually have limitations. The traditional current method depends on a high-precision sensor, but due to the influence of environmental interference and device noise, it is often difficult to achieve high-precision and wide-range monitoring. In addition, due to the complex electromagnetic wave propagation path inside the device, the existing partial discharge source positioning technology generally has low precision, and cannot position the partial discharge source in real time and accurately, thereby affecting the timeliness and reliability of fault early warning. SUMMARY

[0003] The application provides a high-precision monitoring method and system for partial discharge current pulse signals, aiming to solve the technical problem that the existing partial discharge monitoring method is easily affected by electromagnetic interference in a detection blind area, and weak signal recognition is insufficient, so that the partial discharge pulse signals inside a transformer cannot be accurately extracted and analyzed, and accurate positioning of a partial discharge source is affected, so as to achieve the technical effect of high-precision positioning of the partial discharge source by activating a distributed wideband monitoring device for continuous monitoring, and combining multi-conductor transmission line model simulation and pulse feature set analysis.

[0004] In a first aspect, the application discloses a high-precision monitoring method for partial discharge current pulse signals, which comprises the following steps: activating a distributed wideband monitoring device to perform continuous distributed monitoring on a transformer to obtain distributed monitoring information; extracting first monitoring information in the distributed monitoring information, collecting features of a first pulse signal in the first monitoring information to obtain a first feature set, and composing a pulse feature set; establishing a multi-conductor transmission line model based on multi-dimensional feature parameters of the transformer, performing propagation simulation on the multi-conductor transmission line model to obtain simulation information; and calling a partial discharge positioning strategy to cooperatively position and analyze the pulse feature set and the simulation information, and determining a partial discharge source of the transformer.

[0005] Further, the method comprises the following steps: Multiple measuring terminals of the distributed broadband monitoring device are sequentially deployed to preset locations on the transformer; a first measuring terminal is extracted from the multiple measuring terminals, and the first measuring terminal corresponds to a first location among the preset locations; partial discharge continuity is monitored on the first location through the first measuring terminal to obtain the first monitoring information; the distributed monitoring information is composed based on the first monitoring information.

[0006] Furthermore, the method includes: The preset components include at least the high-voltage high-pressure end screen grounding wire, the iron core grounding wire, the outer shell grounding wire, and the neutral point grounding wire.

[0007] Furthermore, the method includes: Collect the structural characteristic parameters of the transformer; collect the material characteristic parameters of the transformer; combine the structural characteristic parameters and the material characteristic parameters to calculate the electrical characteristic parameters; the structural characteristic parameters, the material characteristic parameters, and the electrical characteristic parameters constitute the multidimensional characteristic parameters.

[0008] Furthermore, the method includes: Obtain the winding connection method of the transformer; match the winding modeling plan corresponding to the winding connection method; construct the multi-conductor transmission line model based on the winding modeling plan and the multi-dimensional feature parameters; wherein, matching the winding modeling plan corresponding to the winding connection method includes: if the winding connection method is a continuous winding, the winding modeling plan refers to modeling the winding as a uniform transmission line; if the winding connection method is a tangled or helical winding, the winding modeling plan refers to modeling each turn in the winding as a transmission line.

[0009] Furthermore, the method includes: A set of computational ports for the multi-conductor transmission line model is constructed; the multi-terminal transmission characteristics of the multi-conductor transmission line model are simulated and analyzed using bushing capacitance as a simulation constraint to obtain the simulation information; wherein, the simulation information includes the simulation results of the multi-terminal transmission characteristics of each port in the set of computational ports, and the set of computational ports includes at least the high-voltage winding start end, the high-voltage winding end, the low-voltage winding start end, the low-voltage winding end, the core, and the outer shell.

[0010] Furthermore, the method includes: Obtain the first feature set from the pulse feature set, wherein the first feature set includes a first equivalent duration and a first equivalent bandwidth; form a pulse feature curve according to the correspondence between the first equivalent duration and the first equivalent bandwidth; calculate the first spatial distance from the first coordinate corresponding to the first feature set to the pulse feature curve; if the first spatial distance is not at a predetermined distance threshold, add the first part corresponding to the first feature set to the candidate partial discharge source list; analyze the candidate partial discharge source list based on the simulation information according to the partial discharge localization strategy to determine the partial discharge source.

[0011] Furthermore, the method includes: Extract the first simulation result group from the simulation information, wherein the first simulation result group includes multiple simulation energy ratios, and the multiple simulation energy ratios refer to the energy ratios of multiple ports from the first part to the set of calculation ports; fit the multiple simulation energy ratios to obtain the first fitting curve of the first part; extract the first signal intensity from the first feature set and weight it with a predetermined energy factor to obtain the first monitoring energy ratio; obtain verification information based on the first monitoring energy ratio and the first fitting curve; perform verification analysis on the candidate partial discharge source list based on the verification information, and determine the partial discharge source.

[0012] Furthermore, the method includes: Based on the first monitoring energy ratio, a first monitoring fitting curve is obtained for the first part; the first monitoring fitting curve is compared with the first fitting curve to obtain the minimum value at the maximum distance of the curves; if the minimum value is not at a predetermined threshold, the first part is verified and used as the local discharge source.

[0013] Another aspect of this application discloses a high-precision monitoring system for partial discharge current pulse signals. The system includes: a distributed monitoring module that activates distributed broadband monitoring equipment to continuously monitor a transformer and obtain distributed monitoring information; a feature collection module that extracts first monitoring information from the distributed monitoring information and collects features from the first pulse signal in the first monitoring information to obtain a first feature set, forming a pulse feature set; a propagation simulation module that establishes a multi-conductor transmission line model based on the multi-dimensional characteristic parameters of the transformer and performs propagation simulation on the multi-conductor transmission line model to obtain simulation information; and a location analysis module that retrieves a partial discharge location strategy to perform collaborative location analysis on the pulse feature set and the simulation information to determine the partial discharge source of the transformer.

[0014] One or more technical solutions provided in this application have at least the following technical effects or advantages: The aforementioned high-precision monitoring method for partial discharge current pulse signals first involves activating distributed broadband monitoring equipment to continuously monitor the transformer and acquire monitoring data. Then, the first part of the information is extracted from the monitoring data, and the pulse signals within it are subjected to feature analysis to form a pulse feature set. Next, a transmission line model is established based on the transformer's multi-dimensional characteristic parameters, and the model is simulated to obtain simulation results. Finally, using a partial discharge source location strategy, the pulse feature set is combined with the simulation information, and the partial discharge source of the transformer is determined through collaborative analysis, providing strong support for transformer maintenance and repair.

[0015] The above description is merely an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a high-precision monitoring method for partial discharge current pulse signals in one embodiment.

[0018] Figure 2 This is a diagram of a high-precision monitoring system architecture for partial discharge current pulse signals in one embodiment.

[0019] Figure labeling: Distribution monitoring module 11, Feature collection module 12, Propagation simulation module 13, Location analysis module 14. Detailed Implementation

[0020] This application provides a high-precision monitoring method and system for partial discharge current pulse signals. It solves the technical problem that existing partial discharge monitoring methods are susceptible to electromagnetic interference in the detection blind zone and have insufficient ability to identify weak signals, resulting in the inability to accurately extract and analyze partial discharge pulse signals inside the transformer, which affects the accurate location of partial discharge sources. The method achieves the technical effect of high-precision partial discharge source location by activating distributed broadband monitoring equipment for continuous monitoring and combining multi-conductor transmission line model simulation and pulse feature set analysis.

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0022] It should be noted that the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to such process, method, product, or device.

[0023] Example 1, as Figure 1 As shown, this application provides a high-precision monitoring method for partial discharge current pulse signals, the method comprising: Activate the distributed broadband monitoring equipment to continuously monitor the transformer and obtain distributed monitoring information.

[0024] In this embodiment, firstly, distributed broadband monitoring devices are deployed at multiple key locations of the transformer (such as the high-voltage high-pressure end screen grounding wire and the core grounding wire). These devices employ broadband technology, covering a wide frequency range, thereby enabling continuous real-time monitoring of the transformer's operating status and acquiring current pulse signals at different frequency bands from various parts of the transformer. Once activated, the distributed broadband monitoring devices begin continuous monitoring of the transformer, i.e., uninterruptedly collecting signal data to form multiple monitoring information sets. These monitoring information sets are then aggregated into a single set, forming distributed monitoring information. This provides a foundation for subsequent analysis, helps identify the characteristics of partial discharge signals, and lays the data support for accurately locating potential discharge sources.

[0025] Furthermore, this application provides a method for activating distributed broadband monitoring equipment to perform continuous distributed monitoring of transformers, obtaining distributed monitoring information, including: Multiple measuring terminals of the distributed broadband monitoring device are sequentially deployed to preset locations on the transformer; a first measuring terminal is extracted from the multiple measuring terminals, and the first measuring terminal corresponds to a first location among the preset locations; partial discharge continuity is monitored on the first location through the first measuring terminal to obtain the first monitoring information; the distributed monitoring information is composed based on the first monitoring information.

[0026] Preferably, firstly, multiple measuring terminals of the distributed broadband monitoring equipment are sequentially deployed at multiple key locations on the transformer. These locations typically include areas prone to partial discharge, such as the high-voltage winding, low-voltage winding, core, and casing. Each measuring terminal collects electrical signals via a sensor and transmits these signals to the system for processing. Then, the first measuring terminal (each with a unique identifier) ​​is sequentially selected from the multiple measuring terminals, and its location within the transformer is designated as the first location. This first location can be any of the preset locations, such as the high-voltage winding or the casing grounding wire. Next, this first measuring terminal is used to continuously monitor the partial discharge at the first location, i.e., continuously monitoring the current pulse signal at the first location, collecting changes in the partial discharge signal, and forming first monitoring information. This first monitoring information includes the signal frequency, signal amplitude, and other characteristics of the partial discharge activity at that location, reflecting whether abnormal discharge has occurred and its intensity. Simultaneously, other measuring terminals are used to continuously monitor corresponding locations, obtaining multiple monitoring information sets. Finally, the extracted first monitoring information is combined with the monitoring information from other measurement ends to form comprehensive distributed monitoring information, providing accurate data support for subsequent local discharge source location, fault diagnosis, and other tasks.

[0027] Table 1: Example of Continuous Monitoring Data

[0028] Table 1 above is an example of continuous monitoring data. The table shows the current pulse signal data collected at multiple measurement points on the transformer through distributed broadband monitoring equipment. The signal amplitude (unit: milliampere), signal frequency (unit: hertz), data acquisition timestamp (i.e., the specific time point of acquisition), and total monitoring duration at each measurement end are recorded to help assess the electrical operating status of the transformer.

[0029] Furthermore, this application provides that the preset location includes at least a high-voltage high-pressure end screen grounding wire, an iron core grounding wire, an outer casing grounding wire, and a neutral point grounding wire.

[0030] Preferably, the pre-defined locations of the transformer include at least the high-voltage high-pressure end-screen grounding wire, the core grounding wire, the casing grounding wire, and the neutral point grounding wire. The high-voltage high-pressure end-screen grounding wire is the grounding wire on the high-voltage side of the transformer, responsible for releasing high-voltage current through the ground wire to prevent excessive voltage from damaging the equipment. In partial discharge monitoring, the high-voltage section is a high-risk area for electrical faults, therefore monitoring this part is crucial. The core grounding wire is responsible for guiding any electromagnetic interference and abnormal current generated by the core to the ground. By monitoring the core grounding wire, partial discharges caused by electromagnetic induction or discharge phenomena can be effectively identified. The casing grounding wire prevents the electrical equipment casing from becoming energized, providing protection. In actual operation, electrical faults or discharge phenomena in the casing may lead to safety hazards, therefore monitoring this part can promptly detect potential dangers. The neutral point grounding wire is an important component of transformer grounding. By connecting the neutral point of the electrical equipment to the ground, it ensures electrical balance during normal equipment operation. Monitoring this part can identify equipment abnormalities caused by poor grounding or discharge problems. By sequentially deploying multiple measuring terminals at these preset locations, the partial discharge status of key parts of the transformer can be comprehensively and accurately monitored, ensuring timely detection and location of discharge sources within the transformer, thereby achieving high-precision fault warning and maintenance.

[0031] Extract the first monitoring information from the distributed monitoring information, and collect features from the first pulse signal in the first monitoring information to obtain a first feature set, forming a pulse feature set.

[0032] In one embodiment, firstly, first monitoring information related to the first measuring end is extracted from the obtained distributed monitoring information. This first monitoring information includes electrical signal data of specific parts of the transformer, such as the high-voltage winding or the core grounding wire, reflecting the discharge signal characteristics of that part. Subsequently, the first pulse signal in the extracted first monitoring information is subjected to feature collection to obtain the amplitude, frequency, duration, rise time, fall time, bandwidth, and signal strength of the current pulse. This feature data helps analyze the intensity, frequency, and possible discharge location of partial discharge. By summarizing these feature data, a first feature set is formed. Finally, the first feature set is combined with feature sets from other measuring ends to form a complete pulse feature set, providing data support for subsequent partial discharge source localization and ensuring high-precision fault diagnosis and equipment safety assessment.

[0033] A multi-conductor transmission line model is established based on the multi-dimensional characteristic parameters of the transformer, and propagation simulation is performed on the multi-conductor transmission line model to obtain simulation information.

[0034] In one embodiment, multidimensional characteristic parameters of the transformer are first obtained, including but not limited to the transformer winding connection method, winding size, winding conductivity, mutual inductance between turns, and other factors affecting current propagation. Then, by combining the winding modeling scheme with the multidimensional characteristic parameters, the internal electrical characteristics of the transformer are simulated, thereby constructing a realistic multi-conductor transmission line model. Subsequently, propagation simulation is performed on the constructed multi-conductor transmission line model to accurately simulate the current propagation behavior and generate simulation information. This provides a theoretical basis for subsequent partial discharge source location, helps further analyze the source location and electrical behavior of partial discharge, and provides important data support for accurately locating the discharge source.

[0035] Furthermore, this application provides a method for establishing a multi-conductor transmission line model based on the multi-dimensional characteristic parameters of the transformer, and performing propagation simulation on the multi-conductor transmission line model to obtain simulation information, including: Collect the structural characteristic parameters of the transformer; collect the material characteristic parameters of the transformer; combine the structural characteristic parameters and the material characteristic parameters to calculate the electrical characteristic parameters; the structural characteristic parameters, the material characteristic parameters, and the electrical characteristic parameters constitute the multidimensional characteristic parameters.

[0036] Preferably, before constructing the multi-conductor transmission line model, the transformer design document is read to obtain the transformer's structural characteristic parameters, including the geometric structure information of the windings, such as the winding size, shape, number of turns, turn spacing, and winding connection method—parameters that affect electrical performance. These structural characteristic parameters determine the transformer's electromagnetic field distribution and its current propagation characteristics under operating conditions. Simultaneously, the transformer's material characteristic parameters are also collected, including the conductivity and permeability of the materials used in the windings. Subsequently, based on the collected structural and material characteristic parameters, electrical characteristic parameters are obtained through multiple calculations. These electrical characteristic parameters include, but are not limited to, capacitance parameters (such as inter-turn capacitance), inductance parameters (such as mutual inductance between turns, external self-inductance, and internal self-inductance of the conductor), resistance, and conductance parameters. Specifically, for the capacitance between turns, the parallel plate capacitance extraction method (parallel plate capacitance formula) can be used, considering only the capacitance between adjacent turns and between plates, ignoring the capacitance between non-adjacent turns, and the accurate capacitance value is obtained by solving the capacitance matrix using finite element simulation software. For the mutual inductance between turns, and the external and internal self-inductance of the conductor, the corresponding formulas (such as the mutual inductance formula, external self-inductance formula, and internal self-inductance formula) are used to calculate these inductance parameters, considering the electromagnetic coupling effect between conductors. For the resistance and conductance parameters, the skin effect and proximity effect at high frequencies are considered. The skin effect represents the current concentrating on the conductor surface at high frequencies, while the proximity effect refers to the mutual influence of current between adjacent conductors. The skin effect can be quantified by the skin depth calculation formula. Based on the skin depth, the effective resistance of the conductor is obtained by using the resistance calculation formula through the equivalent surface area method. The proximity effect factor is obtained through finite element simulation or literature experience, and this proximity effect factor is added to 1 and then multiplied by the effective resistance of the conductor to complete the correction of the proximity effect. Finally, the effective conductance of the conductor is calculated by reciprocal of the corrected effective resistance. Finally, the structural, material, and electrical characteristic parameters are summarized to form a multidimensional characteristic parameter, providing comprehensive data support for the subsequent establishment and simulation of multi-conductor transmission line models.

[0037] Table 2: Example Table of Structural Characteristic Parameters

[0038] Table 2 above is an example table of structural characteristic parameters. The table shows the winding dimensions (length × width × height), winding geometry, number of turns, turn spacing, and winding connection method, providing detailed structural parameter support for subsequent multi-conductor transmission line model establishment and simulation analysis.

[0039] Furthermore, this application provides, after composing the multidimensional feature parameters, the following: Obtain the winding connection method of the transformer; match the winding modeling plan corresponding to the winding connection method; construct the multi-conductor transmission line model based on the winding modeling plan and the multi-dimensional feature parameters; wherein, matching the winding modeling plan corresponding to the winding connection method includes: if the winding connection method is a continuous winding, the winding modeling plan refers to modeling the winding as a uniform transmission line; if the winding connection method is a tangled or helical winding, the winding modeling plan refers to modeling each turn in the winding as a transmission line.

[0040] Optionally, the winding connection method of the transformer is first obtained from the structural characteristic parameters. The winding connection method refers to the connection form of each turn in the transformer winding. There are usually different types such as continuous winding, intertwined winding, and helical winding. The winding connection method affects the propagation path of current inside the transformer and the distribution of electromagnetic field. Therefore, clarifying the winding connection method is a prerequisite for establishing an accurate model. Subsequently, the determined winding connection method is matched with the winding modeling scheme identifier. If both the winding modeling scheme identifier and the winding connection method are continuous windings, it means that all turns exhibit similar transmission characteristics in terms of electrical characteristics. That is, the electrical behavior between each turn is consistent, and the current propagation path is physically continuous. In this case, the obtained winding modeling scheme is to model the winding as a uniform transmission line. That is, the entire winding is regarded as a uniform transmission line, ignoring the specific geometric differences between each turn. That is, it is assumed that the inductance, capacitance, resistance and other parameters of each turn are uniformly distributed, and thus an equivalent transmission line model is used for modeling. If both the winding modeling scheme identifier and the winding connection method are tangled winding or spiral winding, it indicates that the position and spacing of each turn in the winding are different, and their electrical characteristics will also differ. In this case, the obtained winding modeling scheme models each turn in the winding as a transmission line, meaning that each transmission line is modeled separately based on its electrical characteristics. Then, based on the determined winding modeling scheme and the aforementioned multi-dimensional feature parameters, a multi-conductor transmission line model is constructed. Specifically, when the winding modeling scheme is equivalent modeling, the structural and material feature parameters are first input into the simulation software for initial modeling. Then, the total inductance, total capacitance, and total resistance of the winding are calculated. By synchronizing these total parameters into the simulation software for secondary modeling, an equivalent transmission line model is generated as the multi-conductor transmission line model. When the winding modeling scheme is individual modeling, initial modeling is also performed first, then each turn is treated as an independent transmission line, and the electrical feature parameters of each turn are synchronized to the corresponding initial modeling results to obtain the multi-conductor transmission line model. This process enables the construction of an accurate multi-conductor transmission line model based on the specific winding connection method and electrical characteristics of the transformer, providing a foundation for subsequent simulation analysis and localization of partial discharge sources.

[0041] Furthermore, this application provides a multi-conductor transmission line model established based on the multi-dimensional characteristic parameters of the transformer, and performs propagation simulation on the multi-conductor transmission line model to obtain simulation information, including: A set of computational ports for the multi-conductor transmission line model is constructed; the multi-terminal transmission characteristics of the multi-conductor transmission line model are simulated and analyzed using bushing capacitance as a simulation constraint to obtain the simulation information; wherein, the simulation information includes the simulation results of the multi-terminal transmission characteristics of each port in the set of computational ports, and the set of computational ports includes at least the high-voltage winding start end, the high-voltage winding end, the low-voltage winding start end, the low-voltage winding end, the core, and the outer shell.

[0042] Optionally, the calculation ports in the multi-conductor transmission line model are first determined. These ports represent the electrical connection points of different parts of the transformer and are key nodes for simulation analysis. The calculation port set includes at least the high-voltage winding start end, high-voltage winding end, low-voltage winding start end, low-voltage winding end, core, and shell. The high-voltage winding start end refers to the input terminal of the transformer's high-voltage winding, usually connected to a high-voltage power supply; the high-voltage winding end refers to the output terminal of the transformer's high-voltage winding, usually connected to a load or power grid; the low-voltage winding start end refers to the input terminal of the transformer's low-voltage winding, usually connected to a low-voltage power supply or load; the low-voltage winding end refers to the output terminal of the transformer's low-voltage winding, usually connected to a load or power grid; the core refers to the transformer's core portion, typically used for magnetic conduction, affecting current propagation; the shell refers to the transformer's metal casing, usually grounded, and provides some electrical protection. This port set will be used in the simulation analysis to calculate the transmission characteristics of each port in the port set by simulating the propagation of current and electromagnetic fields between different ports. During simulation, bushing capacitance is used as a simulation constraint. Bushing capacitance refers to the capacitive coupling effect between the transformer windings and the external environment (such as the core and casing). This capacitance affects signal propagation characteristics, especially under high-frequency conditions. By setting bushing capacitance parameters in the simulation software and then performing multi-terminal transmission characteristic simulation, the current transmission characteristics between different parts of the transformer can be calculated. This includes factors such as current attenuation, propagation speed, and electromagnetic wave reflection. After the above simulation analysis, the simulation software generates simulation information, which includes the multi-terminal transmission characteristic results of each calculated port. These results show the propagation of current between different ports and reflect the influence of bushing capacitance. The simulation information typically includes the current transmission characteristics between each port (such as current amplitude and phase difference), electrical performance parameters of each port (such as input impedance, transmission efficiency, and signal attenuation), and energy ratio. Finally, based on this simulation information, the electrical behavior of the transformer can be analyzed in depth, providing data support for subsequent partial discharge source location.

[0043] The partial discharge localization strategy is used to perform collaborative localization analysis on the pulse feature set and the simulation information to determine the partial discharge source of the transformer.

[0044] In one embodiment, pulse signal characteristics of a specific part of the transformer are first obtained from a pulse feature set. These characteristic data are then combined with transformer simulation information to calculate the signal propagation path and location, constructing a candidate discharge source list. Finally, using a partial discharge localization strategy and combining simulation information, the candidate discharge source list is analyzed to accurately identify the location of the partial discharge source, providing reliable technical support for the safe operation of the transformer and early fault warning.

[0045] Furthermore, this application provides a partial discharge localization strategy for co-localizing the pulse feature set and the simulation information to determine the partial discharge source of the transformer, including: Obtain the first feature set from the pulse feature set, wherein the first feature set includes a first equivalent duration and a first equivalent bandwidth; form a pulse feature curve according to the correspondence between the first equivalent duration and the first equivalent bandwidth; calculate the first spatial distance from the first coordinate corresponding to the first feature set to the pulse feature curve; if the first spatial distance is not at a predetermined distance threshold, add the first part corresponding to the first feature set to the candidate partial discharge source list; analyze the candidate partial discharge source list based on the simulation information according to the partial discharge localization strategy to determine the partial discharge source.

[0046] Optionally, a first feature set is extracted from the collected pulse feature set. This first feature set includes important information related to the partial discharge signal, such as the equivalent duration and equivalent bandwidth of the pulse signal. The equivalent duration refers to the duration of the pulse signal in the time domain, and the equivalent bandwidth refers to the bandwidth covered by the signal in the frequency domain. These features can more accurately describe the time and frequency domain characteristics of the partial discharge. Subsequently, based on the correspondence between the obtained first equivalent duration and first equivalent bandwidth, the first equivalent duration is used as the horizontal axis and the first equivalent bandwidth as the vertical axis. The least squares method is used to minimize the sum of squared errors between the fitted curve and the data points to find the optimal fitted curve, thereby plotting the pulse feature curve. This curve displays the overall characteristics of the partial discharge signal and provides intuitive data support for subsequent analysis. Afterward, based on the pulse feature curve, the first spatial distance between the first coordinate corresponding to the first feature set (any coordinate in the first feature set) and the nearest point in the pulse feature curve is calculated using Euclidean distance. This first spatial distance reflects the deviation between the actual monitored signal and the theoretical characteristics, and can effectively assess the authenticity and accuracy of the partial discharge signal. If the calculated first spatial distance is not within the preset distance threshold range, it indicates that the signal fails to meet the predetermined discharge mode. In this case, the monitoring location corresponding to the first feature set (i.e., the first location) is added to the candidate partial discharge source list. Then, the partial discharge location strategy is invoked to further analyze each location in the candidate partial discharge source list. By combining with simulation information, the difference between the actual monitoring data and the simulation results is compared to determine whether a partial discharge source actually exists in the candidate location, thereby accurately locating the location of the partial discharge source and ensuring the safe operation of the transformer.

[0047] Furthermore, this application provides a method for analyzing the candidate partial discharge source list based on the simulation information according to the partial discharge localization strategy to determine the partial discharge source, including: Extract the first simulation result group from the simulation information, wherein the first simulation result group includes multiple simulation energy ratios, and the multiple simulation energy ratios refer to the energy ratios of multiple ports from the first part to the set of calculation ports; fit the multiple simulation energy ratios to obtain the first fitting curve of the first part; extract the first signal intensity from the first feature set and weight it with a predetermined energy factor to obtain the first monitoring energy ratio; obtain verification information based on the first monitoring energy ratio and the first fitting curve; perform verification analysis on the candidate partial discharge source list based on the verification information, and determine the partial discharge source.

[0048] Optionally, a first set of simulation results is extracted from the previously obtained simulation information. This set contains multiple simulated energy ratios, which refer to the ratio of signal strength between multiple ports in the calculation port set from the first location. Specifically, it is the ratio of the signal strength of the partial discharge source to the signal strength received at the port, reflecting the energy attenuation of the signal as it propagates from the partial discharge source to different ports. Multiple simulated energy ratios provide electrical coupling information between different ports, which helps in analyzing the signal propagation characteristics. Subsequently, the extracted multiple simulated energy ratio data are fitted using the same fitting direction as described above to obtain a first fitting curve, serving as the mathematical relationship between the simulated energy ratio and the calculation port, providing a benchmark for subsequent verification analysis. Next, a first signal strength is extracted from the first feature set. This first signal strength represents the intensity of the monitored partial discharge signal. Then, the signal strength is weighted using a predetermined energy factor to obtain a first monitored energy ratio. The predetermined energy factor can be set according to the signal strength received at the port. Finally, the first monitored energy ratio is compared with the first fitting curve to obtain verification information. By comparing the difference between the actual monitored energy ratio and the fitted curve, it is determined whether the signal propagation behavior conforms to the expected discharge mode. If the difference between the energy ratio and the fitted curve is small, it indicates a high degree of matching between the signal and the simulation model; otherwise, an anomaly may exist. Finally, the obtained verification information is evaluated. If the verification results show an anomaly, the first part corresponding to this first feature set is added to the partial discharge source. In addition, the same verification analysis is performed on other candidate parts in the candidate partial discharge source list to determine the verification information of each candidate part. Based on this, the final partial discharge source is determined, providing strong data support for transformer fault diagnosis, early warning, and maintenance.

[0049] Furthermore, this application provides a verification analysis of the candidate partial discharge source list based on the verification information, and a determination of the partial discharge source, including: Based on the first monitoring energy ratio, a first monitoring fitting curve is obtained for the first part; the first monitoring fitting curve is compared with the first fitting curve to obtain the minimum value at the maximum distance of the curves; if the minimum value is not at a predetermined threshold, the first part is verified and used as the local discharge source.

[0050] Optionally, firstly, by calculating the first monitoring energy ratio, a first monitoring fitting curve for the first location is constructed using the same fitting process described above. This fitting curve reflects the transmission characteristics of the partial discharge signal at the first location. Then, the first monitoring fitting curve is compared and analyzed with the previous first fitting curve. The difference between the two curves at various data points is calculated using Euclidean distance, and several difference values ​​with the largest vertical distance in the first monitoring fitting curve are extracted, with the minimum value selected. This minimum value is then compared with a predetermined threshold. If the minimum value is found to be outside the predetermined threshold, it indicates a significant difference between the actual monitoring data and the simulated curve. In this case, the first location is considered to have passed partial discharge verification and is a partial discharge source, providing a basis for subsequent fault diagnosis and repair.

[0051] In summary, the embodiments of this application have at least the following technical effects: This embodiment first activates a distributed broadband monitoring device to continuously monitor the transformer, obtaining distributed monitoring information. Then, it extracts the first monitoring information from the distributed monitoring information and collects features from the first pulse signal in the first monitoring information to obtain a first feature set, forming a pulse feature set. Next, it establishes a multi-conductor transmission line model based on the transformer's multi-dimensional characteristic parameters and performs propagation simulation on the multi-conductor transmission line model to obtain simulation information. Finally, it retrieves a partial discharge localization strategy to perform collaborative localization analysis on the pulse feature set and the simulation information to determine the partial discharge source of the transformer. These technical effects collectively solve the technical problems of existing partial discharge monitoring methods, which are susceptible to electromagnetic interference in the detection blind zone and have insufficient recognition of weak signals, leading to the inability to accurately extract and analyze the partial discharge pulse signal inside the transformer, thus affecting the accurate localization of the partial discharge source. This achieves the technical effect of high-precision partial discharge source localization by activating a distributed broadband monitoring device for continuous monitoring and combining multi-conductor transmission line model simulation with pulse feature set analysis.

[0052] Example 2, based on the same inventive concept as the high-precision monitoring method for partial discharge current pulse signals in the foregoing examples, such as... Figure 2As shown, this application provides a high-precision monitoring system for partial discharge current pulse signals. The system includes: a distributed monitoring module 11: activating a distributed broadband monitoring device to continuously monitor the transformer and obtain distributed monitoring information; a feature collection module 12: extracting first monitoring information from the distributed monitoring information and collecting features from the first pulse signal in the first monitoring information to obtain a first feature set, forming a pulse feature set; a propagation simulation module 13: establishing a multi-conductor transmission line model based on the multi-dimensional characteristic parameters of the transformer and performing propagation simulation on the multi-conductor transmission line model to obtain simulation information; and a location analysis module 14: retrieving a partial discharge location strategy to perform collaborative location analysis on the pulse feature set and the simulation information to determine the partial discharge source of the transformer.

[0053] Furthermore, the distribution monitoring module 11 is also used to perform the following method: Multiple measuring terminals of the distributed broadband monitoring device are sequentially deployed to preset locations on the transformer; a first measuring terminal is extracted from the multiple measuring terminals, and the first measuring terminal corresponds to a first location among the preset locations; partial discharge continuity is monitored on the first location through the first measuring terminal to obtain the first monitoring information; the distributed monitoring information is composed based on the first monitoring information.

[0054] Furthermore, the distribution monitoring module 11 is also used to perform the following method: The preset components include at least the high-voltage high-pressure end screen grounding wire, the iron core grounding wire, the outer shell grounding wire, and the neutral point grounding wire.

[0055] Furthermore, the propagation simulation module 13 is also used to perform the following method: Collect the structural characteristic parameters of the transformer; collect the material characteristic parameters of the transformer; combine the structural characteristic parameters and the material characteristic parameters to calculate the electrical characteristic parameters; the structural characteristic parameters, the material characteristic parameters, and the electrical characteristic parameters constitute the multidimensional characteristic parameters.

[0056] Furthermore, the propagation simulation module 13 is also used to perform the following method: Obtain the winding connection method of the transformer; match the winding modeling plan corresponding to the winding connection method; construct the multi-conductor transmission line model based on the winding modeling plan and the multi-dimensional feature parameters; wherein, matching the winding modeling plan corresponding to the winding connection method includes: if the winding connection method is a continuous winding, the winding modeling plan refers to modeling the winding as a uniform transmission line; if the winding connection method is a tangled or helical winding, the winding modeling plan refers to modeling each turn in the winding as a transmission line.

[0057] Furthermore, the propagation simulation module 13 is also used to perform the following method: A set of computational ports for the multi-conductor transmission line model is constructed; the multi-terminal transmission characteristics of the multi-conductor transmission line model are simulated and analyzed using bushing capacitance as a simulation constraint to obtain the simulation information; wherein, the simulation information includes the simulation results of the multi-terminal transmission characteristics of each port in the set of computational ports, and the set of computational ports includes at least the high-voltage winding start end, the high-voltage winding end, the low-voltage winding start end, the low-voltage winding end, the core, and the outer shell.

[0058] Furthermore, the positioning analysis module 14 is also used to perform the following methods: Obtain the first feature set from the pulse feature set, wherein the first feature set includes a first equivalent duration and a first equivalent bandwidth; form a pulse feature curve according to the correspondence between the first equivalent duration and the first equivalent bandwidth; calculate the first spatial distance from the first coordinate corresponding to the first feature set to the pulse feature curve; if the first spatial distance is not at a predetermined distance threshold, add the first part corresponding to the first feature set to the candidate partial discharge source list; analyze the candidate partial discharge source list based on the simulation information according to the partial discharge localization strategy to determine the partial discharge source.

[0059] Furthermore, the positioning analysis module 14 is also used to perform the following methods: Extract the first simulation result group from the simulation information, wherein the first simulation result group includes multiple simulation energy ratios, and the multiple simulation energy ratios refer to the energy ratios of multiple ports from the first part to the set of calculation ports; fit the multiple simulation energy ratios to obtain the first fitting curve of the first part; extract the first signal intensity from the first feature set and weight it with a predetermined energy factor to obtain the first monitoring energy ratio; obtain verification information based on the first monitoring energy ratio and the first fitting curve; perform verification analysis on the candidate partial discharge source list based on the verification information, and determine the partial discharge source.

[0060] Furthermore, the positioning analysis module 14 is also used to perform the following methods: Based on the first monitoring energy ratio, a first monitoring fitting curve is obtained for the first part; the first monitoring fitting curve is compared with the first fitting curve to obtain the minimum value at the maximum distance of the curves; if the minimum value is not at a predetermined threshold, the first part is verified and used as the local discharge source.

[0061] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0062] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0063] This specification and accompanying drawings are merely illustrative examples of this application and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Therefore, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A method for high-precision monitoring of partial discharge current pulse signals, characterized in that The method comprises the following steps: activating a distributed broadband monitoring device to continuously monitor the transformer to obtain distributed monitoring information; extracting first monitoring information from the distributed monitoring information, collecting features of first pulse signals in the first monitoring information to obtain a first feature set, and forming a pulse feature set; establishing a multi-conductor transmission line model based on multi-dimensional feature parameters of the transformer, and performing propagation simulation on the multi-conductor transmission line model to obtain simulation information; calling a partial discharge positioning strategy to cooperatively locate and analyze the pulse feature set and the simulation information to determine the partial discharge source of the transformer.

2. The method of claim 1, wherein the partial discharge current pulse signal is monitored with high precision. The method comprises the following steps: activating a distributed broadband monitoring device to continuously monitor the transformer to obtain distributed monitoring information, comprising: sequentially arranging multiple measurement ends of the distributed broadband monitoring device to predetermined positions of the transformer; extracting a first measurement end from the multiple measurement ends, and the first measurement end corresponds to a first position in the predetermined positions; continuously monitoring the first position by the first measurement end to obtain the first monitoring information; 3. The method of claim 2, wherein the step of determining the amplitude of the partial discharge current pulse signal is performed by: determining a peak value of the partial discharge current pulse signal; and determining the amplitude of the partial discharge current pulse signal based on the peak value of the partial discharge current pulse signal. forming the distributed monitoring information based on the first monitoring information.

4. The method of claim 1, wherein the partial discharge current pulse signal is monitored with high precision. The predetermined positions at least include high-voltage high-tube end screen grounding wire, core grounding wire, shell grounding wire and neutral point grounding wire. Before establishing a multi-conductor transmission line model based on multi-dimensional feature parameters of the transformer, and performing propagation simulation on the multi-conductor transmission line model to obtain simulation information, the method comprises the following steps: collecting structural feature parameters of the transformer; collecting material feature parameters of the transformer; combining the structural feature parameters and the material feature parameters to calculate electrical feature parameters; 5. The method of claim 4, wherein the step of determining the amplitude of the partial discharge current pulse signal is performed by: determining a peak value of the partial discharge current pulse signal; and determining the amplitude of the partial discharge current pulse signal based on the peak value of the partial discharge current pulse signal. the structural feature parameters, the material feature parameters and the electrical feature parameters form the multi-dimensional feature parameters. After forming the multi-dimensional feature parameters, the method comprises the following steps: obtaining the winding connection mode of the transformer; matching the winding modeling plan corresponding to the winding connection mode; constructing the multi-conductor transmission line model according to the winding modeling plan and combining the multi-dimensional feature parameters; wherein matching the winding modeling plan corresponding to the winding connection mode comprises: if the winding connection mode is continuous winding, the winding modeling plan means to model the winding as a uniform transmission line; 6. The method of claim 2, wherein the step of monitoring the partial discharge current pulse signal with high precision is characterized by, if the winding connection mode is a twisted or spiral winding, each turn of the winding is modeled as a transmission line. Establishing a multi-conductor transmission line model based on multi-dimensional feature parameters of the transformer, and performing propagation simulation on the multi-conductor transmission line model to obtain simulation information, comprising: assembling a calculation port set of the multi-conductor transmission line model; performing multi-end transmission characteristic simulation analysis on the multi-conductor transmission line model with the sleeve capacitance as the simulation constraint to obtain the simulation information; wherein the simulation information includes multi-end transmission characteristic simulation results of each port in the calculation port set, and the calculation port set at least includes high-voltage winding first end, high-voltage winding end, low-voltage winding first end, low-voltage winding end, core and shell.

7. The method of claim 6, wherein the step of determining the amplitude of the partial discharge current pulse signal is performed by: determining a peak value of the partial discharge current pulse signal; and determining the amplitude of the partial discharge current pulse signal based on the peak value of the partial discharge current pulse signal. The local discharge positioning strategy is used to cooperatively position and analyze the pulse feature set and the simulation information, to determine the local discharge source of the transformer, including: The first feature set in the pulse feature set is acquired, and the first feature set includes a first equivalent time length and a first equivalent frequency width; A pulse feature curve is formed according to the corresponding relationship between the first equivalent time length and the first equivalent frequency width; A first spatial distance of a first coordinate corresponding to the first feature set to the pulse feature curve is calculated; If the first spatial distance is not within a predetermined distance threshold, the first part corresponding to the first feature set is added to a candidate local discharge source list; According to the local discharge positioning strategy, the candidate local discharge source list is analyzed based on the simulation information, to determine the local discharge source.

8. The method of claim 7, wherein the step of determining the amplitude of the partial discharge current pulse signal is performed by: determining a peak value of the partial discharge current pulse signal; and determining the amplitude of the partial discharge current pulse signal based on the peak value of the partial discharge current pulse signal. According to the local discharge positioning strategy, the candidate local discharge source list is analyzed based on the simulation information, to determine the local discharge source, including: A first simulation result group in the simulation information is extracted, wherein the first simulation result group includes a plurality of simulation energy ratios, and the plurality of simulation energy ratios refer to energy ratios of the first part to a plurality of ports in the calculation port set; The plurality of simulation energy ratios are fitted to obtain a first fitting curve of the first part; A first signal strength in the first feature set is extracted, and a first monitoring energy ratio is obtained by weighting a predetermined energy factor; According to the first monitoring energy ratio and the first fitting curve, verification information is obtained; According to the verification information, verification analysis of the candidate local discharge source list is performed, and the local discharge source is determined.

9. The method of claim 8, wherein the step of determining the amplitude of the partial discharge current pulse signal is performed by: determining a peak value of the partial discharge current pulse signal; and determining the amplitude of the partial discharge current pulse signal based on the peak value of the partial discharge current pulse signal. According to the verification information, verification analysis of the candidate local discharge source list is performed, and the local discharge source is determined, including: A first monitoring fitting curve of the first part is obtained based on the first monitoring energy ratio; The first monitoring fitting curve and the first fitting curve are compared to obtain a minimum value at a maximum distance of the curves; If the minimum value is not within a predetermined threshold, the first part passes the verification and is taken as the local discharge source.

10. A high-precision monitoring system of partial discharge current pulse signals, characterized in that, The system is used to perform the high-precision monitoring method of the partial discharge current pulse signal according to any one of claims 1-9, including: A distributed monitoring module: activating a distributed wideband monitoring device to continuously monitor the transformer to obtain distributed monitoring information; A feature collection module: extracting first monitoring information in the distributed monitoring information, and collecting features of a first pulse signal in the first monitoring information to obtain a first feature set, to form a pulse feature set; A propagation simulation module: establishing a multi-conductor transmission line model based on multi-dimensional feature parameters of the transformer, and performing propagation simulation on the multi-conductor transmission line model to obtain simulation information; A positioning analysis module: using the local discharge positioning strategy to cooperatively position and analyze the pulse feature set and the simulation information, to determine the local discharge source of the transformer.

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