A method and system for medium and low voltage collaborative self-healing for global user fast power restoration

Abstract

This invention relates to the field of medium- and low-voltage distribution network collaborative self-healing technology, and provides a medium- and low-voltage collaborative self-healing method and system for rapid power restoration for all users in the region. The method includes: receiving medium-voltage permanent fault information, initiating medium-voltage self-healing, locating the fault and remotely isolating the faulty area, and remotely restoring power to the non-faulty medium-voltage area; collecting real-time conductor temperature on the low-voltage side of the distribution transformer, duration of voltage dips on the low-voltage busbar, power consumption priority of users connected to the distribution transformer, topological distance between the distribution transformer to be transferred to low-voltage distribution and the target distribution transformer, and actual load current of the distribution transformer to be transferred to low-voltage distribution, to achieve dynamic load verification of the low-voltage transfer of the distribution transformer; based on the medium-voltage fault information and the above-mentioned collected parameters, this invention achieves rapid self-healing power restoration for all users in the region under fault conditions through the linkage and collaboration of medium-voltage self-healing and low-voltage self-healing. Simultaneously, by realizing dynamic load verification of the low-voltage transfer of the distribution transformer, it can effectively reduce low-voltage transfer overload tripping and improve the power restoration efficiency and power supply stability for all users in the region.

Description

Technical Field

[0001] This invention relates to the field of medium and low voltage distribution network collaborative self-healing technology, specifically to a medium and low voltage collaborative self-healing method and system for rapid power restoration for all users in the region. Background Technology

[0002] Distribution network self-healing is a core technology for improving power supply reliability. Current mainstream solutions focus on medium-voltage side fault handling, which involves locating and isolating faulty areas and restoring power to non-faulty areas. However, there are significant technical shortcomings: low-voltage distribution transformer users in medium-voltage fault areas cannot be restored through medium-voltage self-healing, forming a "medium-voltage self-healing power restoration dead zone". These users need to rely on manual on-site operation for restoration, with power outages lasting up to several hours, which seriously affects the efficiency of power restoration across the entire area.

[0003] Meanwhile, some schemes involving low-voltage power transfer use the static rated current of the distribution transformer's low-voltage side as the basis for safety verification, without considering dynamic parameters such as real-time conductor temperature and the duration of low-voltage bus voltage dips. Under extreme conditions, conductor current-carrying capacity fluctuates greatly, and the static limit deviates significantly from the actual carrying capacity, which can easily lead to overload tripping after power transfer, further prolonging the restoration time.

[0004] Therefore, existing technologies cannot cover the power restoration needs of low-voltage users in the fault area, and the low-voltage verification method has safety risks. There is an urgent need to extend the self-healing capability to the low-voltage side and build a medium- and low-voltage collaborative self-healing solution. Through the coordinated linkage of medium-voltage self-healing and low-voltage self-healing, the dead zone for power restoration in the medium-voltage fault area and the dynamic load verification problem of low-voltage transfer can be solved, so as to achieve rapid power restoration for all users in the area. Summary of the Invention

[0005] The purpose of this invention is to provide a medium- and low-voltage collaborative self-healing method for rapid power restoration for all users, comprising:

[0006] S1. Receive information about permanent medium-voltage faults, locate the fault on the medium-voltage side and remotely isolate the faulty area, and remotely restore power to the non-faulty medium-voltage area.

[0007] S2. Collect real-time temperature of low-voltage side conductors, duration of low-voltage bus voltage dip, power priority of users connected to the distribution transformer, topological distance between the distribution transformer to be transferred and the target distribution transformer, and actual load current of the distribution transformer to be transferred, to realize dynamic load verification of low-voltage power transfer of the distribution transformer.

[0008] S3. Based on the medium-voltage permanent fault information and the above-mentioned collected parameters, for the fault area, determine the set of undervoltage distribution transformers, perform low-voltage self-healing start boundary verification of the undervoltage distribution transformers, and determine the set of distribution transformers to be self-healed at low voltage.

[0009] S4. Perform low-voltage topology analysis on the low-voltage self-healing distribution transformer set to identify interconnected distribution transformer groups, and search for low-voltage direct-to-electricity conversion schemes on a distribution transformer group basis.

[0010] S5. Prioritize and verify the power flow of the direct transfer scheme, and realize the automatic low-voltage transfer of the lost-voltage distribution transformer through low-voltage self-healing to restore the power supply to low-voltage users in the fault area.

[0011] S6. The power transfer scheme is executed according to the parallel sequence between distribution transformer groups and the priority descending order within the distribution transformer group. If the switch remote control fails, the above parameters are collected again and the low-voltage power transfer scheme is updated until the power is restored to all users in the area.

[0012] Preferably, S2 specifically includes: real-time conductor temperature is obtained through a temperature sensor; the duration of low-voltage bus voltage dip is obtained through a power quality monitoring terminal; user power priority is obtained from the power marketing system; topology distance is obtained from the distribution network GIS system; and actual load current is obtained through a low-voltage automation terminal. The parameter acquisition process is started synchronously with the medium-voltage side fault isolation step, and the acquisition frequency is set to once per second to ensure parameter timeliness. After acquisition, the parameters are standardized and uniformly converted into a numerical format that the system can recognize before being used for subsequent distribution transformer set analysis.

[0013] Further preferred, S3 specifically includes: parsing the list of unpowered distribution transformers contained in the medium-voltage fault information, extracting the distribution transformer number, the distribution transformer to which it belongs, and the load type information to form a set of distribution transformers with lost voltage; selecting distribution transformers with low-voltage automation terminals, available low-voltage tie switches, and normal communication channels from the set of distribution transformers with lost voltage, excluding distribution transformers without low-voltage transfer conditions, to form a set of distribution transformers to be self-healed under low voltage; performing pre-verification on each distribution transformer to be self-healed under low voltage, the pre-verification content including whether the distribution transformer is in a locked state, whether the low-voltage main switch is in the closed position, whether there is a fault signal on the low-voltage main switch, and whether the dynamic carrying capacity of the distribution transformer meets the basic load requirements, and including distribution transformers that meet all pre-verification conditions in the set of distribution transformers to be self-healed under low voltage.

[0014] Further preferably, in S4, the step of searching for low-voltage direct transfer schemes includes: calling the distribution network low-voltage topology database to obtain the low-voltage tie switch connection relationship, conductor type, and power supply radius information of all distribution transformers in the low-voltage self-healing distribution transformer set; based on the tie switch connection relationship, dividing the distribution transformers with direct low-voltage tie paths into the same distribution transformer group; searching for direct transfer schemes within each distribution transformer group, with search conditions including the low-voltage tie switch being in the open position, the low-voltage main switch of the opposite distribution transformer being in the closed position, the three-phase voltage of the low-voltage busbar of the opposite distribution transformer meeting the voltage standard, and the sum of the actual load current of the distribution transformer to be transferred and the current load current of the opposite distribution transformer not exceeding the initial threshold of the dynamic maximum allowable current of the opposite distribution transformer; and searching for at least two direct transfer schemes for each distribution transformer to be transferred, forming a candidate scheme library.

[0015] Furthermore, the dynamic maximum allowable current is calculated using the following formula:

[0016] ;

[0017] In the formula, This is the maximum allowable dynamic current of the transformer on the opposite side. This is the rated current of the low-voltage side of the transformer on the opposite side. The temperature coefficient of the conductor material in low-voltage lines. Real-time temperature of the conductor. The reference temperature for the conductor. This is the line loss correction factor for low-voltage lines. The actual load current of the distribution transformer to be transferred. This refers to the duration of the low-voltage bus voltage dip. This is the rated voltage of the low-voltage busbar. For the apparent capacity of the transformer on the opposite side, It is a natural constant.

[0018] More preferably, in S5, the priority sorting includes calculating priority coefficients and sorting the priority coefficients, wherein the priority coefficients are calculated using the following formula:

[0019] ;

[0020] In the formula, This is the priority coefficient for the power conversion scheme. The priority weight of electricity consumption for users connected to the distribution transformer to be transferred. For the load rate of the distribution transformer to be transferred and , This is the maximum allowable dynamic current of the transformer on the opposite side. The actual load current of the distribution transformer to be transferred. This refers to the topological distance between the distribution transformer to be transferred and the distribution transformer on the opposite side. The number of high-priority users connected to the distribution transformer awaiting transfer. The total number of users served by the distribution transformer to be transferred; sort the direct transfer schemes in the alternative scheme library from largest to smallest according to the priority coefficient, and select the scheme ranked first as the target transfer scheme.

[0021] More preferably, in S5, the power flow verification is calculated using the following formula:

[0022] ;

[0023] In the formula, for The total equivalent load current of the power supply transformer to be transferred to the station. For the first The actual load current of the distribution transformer awaiting transfer. For the first The adaptive adjustment coefficient of the distribution transformer to be transferred to the platform and , For the first Taiwan's supply transfer and distribution delay time. The maximum allowable dynamic current of the target power supply transformer; if the total equivalent load current exceeds Then, the transformers to be transferred to the distribution system are eliminated in order of priority coefficient from low to high until the verification conditions are met.

[0024] A medium- and low-voltage collaborative self-healing system for rapid power restoration for all users is provided, applied to any of the aforementioned medium- and low-voltage collaborative self-healing methods for rapid power restoration for all users. The system includes a medium-voltage self-healing interaction module, a multi-dimensional parameter acquisition module, a distribution transformer analysis module, a low-voltage power transfer decision module, and an execution control module. The medium-voltage self-healing interaction module receives medium-voltage permanent fault information and medium-voltage self-healing action results, and outputs medium-voltage fault information to the distribution transformer analysis module. The multi-dimensional parameter acquisition module is electrically connected to the medium-voltage self-healing interaction module, acquires low-voltage side parameters, standardizes them, and outputs them to the distribution transformer analysis module. The distribution transformer analysis module is electrically connected to the multi-dimensional parameter acquisition module, completes distribution transformer set analysis, and outputs the activation of the low-voltage self-healing distribution transformer set to the low-voltage power transfer decision module. The low-voltage power transfer decision module is electrically connected to the distribution transformer analysis module, generates a power transfer scheme, and outputs it to the execution control module. The execution control module is electrically connected to the low-voltage power transfer decision module, executes the power transfer scheme, and triggers parameter re-acquisition when a switch fails.

[0025] A further preferred embodiment of the multi-dimensional parameter acquisition module includes a temperature acquisition unit, a power quality monitoring unit, a user information interaction unit, and a topology data acquisition unit. The temperature acquisition unit acquires conductor temperature, the power quality monitoring unit acquires voltage sag duration, the user information interaction unit acquires user power priority, and the topology data acquisition unit acquires topology distance. Each unit is electrically connected to the distribution transformer analysis module and uses a unified data transmission protocol to synchronously transmit parameters, ensuring data real-time performance and consistency. The temperature acquisition unit supports uploading data from multiple measurement points, and the power quality monitoring unit can generate a power quality analysis report.

[0026] In a further optimized configuration, the low-voltage power transfer decision module includes a topology analysis unit, a scheme ranking unit, and a verification unit. The topology analysis unit identifies the distribution transformer group and outputs the result to the scheme ranking unit. The scheme ranking unit calls the priority coefficient model to rank the power transfer schemes and outputs the result to the verification unit. The verification unit calls the power flow verification model to calculate the total equivalent load current, eliminates distribution transformers that do not meet the conditions, and generates the final low-voltage power transfer scheme. The topology analysis unit, scheme ranking unit, and verification unit are electrically connected in sequence and transmit data in real time through internal interfaces to ensure that the scheme meets the safety and power restoration priority requirements.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] This invention extends self-healing technology to the low-voltage user side, achieving coordinated operation of medium-voltage and low-voltage self-healing. It enables rapid power restoration for low-voltage users in fault-affected distribution transformer areas, resolving the power restoration dead zone issue in medium-voltage self-healing and meeting the rapid self-healing power restoration needs of all users. Furthermore, it breaks through the conventional approach of static current limits by introducing dynamic parameter acquisition, such as real-time conductor temperature on the low-voltage side and the duration of low-voltage bus voltage dips. This data, combined with medium-voltage fault information, completes transformer set screening, power transfer scheme search and verification, and re-acquires parameters to update the scheme when switch remote control fails, forming a closed-loop control. This technology precisely addresses the core problem in the background technology where static current limits are not combined with low-voltage side dynamic parameters, leading to easy overload tripping of lines after power transfer. It avoids the deviation between static limits and actual carrying capacity under extreme conditions, effectively reducing overload tripping and improving the power restoration efficiency and power supply stability for all users. Attached Figure Description

[0029] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0030] Figure 1 This is a flowchart of the medium- and low-voltage collaborative self-healing method for rapid power restoration for all users in this invention.

[0031] Figure 2 This is a connection block diagram of the medium- and low-voltage collaborative self-healing system for rapid power restoration for all users in this invention.

[0032] Figure 3 This is a typical wiring diagram of the distribution transformer unit of the present invention. Detailed Implementation

[0033] 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, and 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.

[0034] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] Existing medium and low voltage collaborative self-healing methods do not integrate multiple parameters such as low voltage side conductor temperature, voltage sag duration, and user power priority. The power transfer scheme uses static current limits and lacks a switch failure retry mechanism, which makes it easy for overload tripping to occur during power restoration, delays in power restoration for high-priority users, and low self-healing efficiency.

[0036] Based on this, please refer to Figures 1-3 This embodiment provides a medium- and low-voltage collaborative self-healing method for rapid power restoration for all users, including:

[0037] S1: Receives information about permanent medium-voltage faults, locates the fault on the medium-voltage side, remotely isolates the faulty area, and remotely restores power to the non-faulty medium-voltage area.

[0038] S2: Collect real-time temperature of low-voltage side conductors, duration of low-voltage bus voltage dip, power priority of users connected to the distribution transformer, topological distance between the distribution transformer to be transferred and the target distribution transformer, and actual load current of the distribution transformer to be transferred, to realize dynamic load verification of low-voltage power transfer of the distribution transformer.

[0039] S3: Based on the medium-voltage permanent fault information and the above-mentioned collected parameters, for the fault area, determine the set of undervoltage distribution transformers, perform low-voltage self-healing start boundary verification of the undervoltage distribution transformers, and determine the set of distribution transformers to be self-healed at low voltage.

[0040] S4: Perform low-voltage topology analysis on the low-voltage self-healing distribution transformer set to identify interconnected distribution transformer groups, and search for low-voltage direct-to-electricity conversion schemes on a distribution transformer group basis.

[0041] S5: Prioritize and verify the power flow of the direct transfer scheme, and realize the automatic low-voltage transfer of the lost-voltage distribution transformer through low-voltage self-healing to restore the power supply to low-voltage users in the fault area.

[0042] S6: The power transfer scheme is executed according to the parallel sequence between distribution transformer groups and the priority descending order within the distribution transformer group. If the switch remote control fails, the above parameters are collected again and the low-voltage power transfer scheme is updated until the power is restored to all users in the area.

[0043] This method constructs a complete process around the coordinated self-healing of medium and low voltage systems. Its core technical features include multi-parameter acquisition, transformer set screening, topology analysis, scheme optimization, and dynamic retry. In the medium-voltage side processing stage, after receiving permanent fault information, the fault point is determined using fault location technology. The medium-voltage switch is remotely operated to isolate the faulty area, while simultaneously remotely restoring power to the medium-voltage lines in the non-faulty areas, restoring basic power supply to the medium-voltage side. Multi-parameter acquisition on the low-voltage side is a crucial prerequisite. The acquired real-time conductor temperature, low-voltage bus voltage sag duration, user power priority, topology distance, and actual load current provide comprehensive data support for subsequent analysis. In the transformer set determination stage, the list of un-energized transformers is analyzed based on the medium-voltage fault information to form a set of transformers with lost voltage. Transformers with low-voltage automation terminals, available tie switches, and normal communication channels are screened to form a set of transformers awaiting low-voltage self-healing. Finally, a pre-verification process is used to determine the set of transformers to initiate self-healing, excluding invalid transformers. The topology analysis process calls upon the distribution network low-voltage topology database and divides distribution transformers with direct interconnection paths into distribution transformer groups based on the connection relationship of tie switches, ensuring that distribution transformers within the group can transfer power to each other; direct transfer schemes are searched on a distribution transformer group basis to avoid invalid cross-group searches.

[0044] In the scheme ranking and verification stage, the schemes are ranked using a priority model, and safety is ensured through power flow calculation. In the execution stage, the schemes are executed in parallel between distribution transformer groups and in descending order of priority within the group. If the remote control of the switch fails, the parameters are immediately re-acquired to update the scheme, so as to avoid secondary failures due to outdated parameters, thus forming a closed-loop control.

[0045] The technical effects of the above embodiments include: achieving multi-parameter collaborative self-healing in medium and low voltage, avoiding overload and high-priority user delays caused by static solutions, solving the problem of power restoration interruption after switch failure, and improving the power restoration efficiency and power supply reliability for all users.

[0046] The existing low-pressure parameter acquisition lacks clear equipment sources and data processing standards. The acquisition process is not synchronized with medium-pressure fault handling, resulting in poor parameter timeliness and incompatible formats, which leads to low accuracy in subsequent distribution transformer set analysis and scheme generation.

[0047] Based on this, in step S2, the real-time conductor temperature is obtained through a temperature sensor, the duration of the low-voltage bus voltage sag is obtained through a power quality monitoring terminal, the user's electricity priority is obtained from the power marketing system, the topology distance is obtained from the distribution network GIS system, and the actual load current is obtained through a low-voltage automation terminal. The parameter acquisition process is started synchronously with the medium-voltage side fault isolation step, and the acquisition frequency is set to once per second to ensure the timeliness of the parameters. After acquisition, the parameters are standardized and uniformly converted into a numerical format that the system can recognize before being used for subsequent distribution transformer set analysis.

[0048] This solution clearly defines the equipment sources, timing control, and data processing standards for parameter acquisition, resolving ambiguity and timeliness issues in the acquisition process. Regarding equipment sources, real-time conductor temperature is acquired through distributed fiber optic temperature sensors or wireless temperature sensors. Distributed fiber optic sensors are laid along low-voltage lines, enabling continuous monitoring at one measuring point every 500 meters with an accuracy of ±0.5℃. Wireless temperature sensors are installed at conductor joints, avoiding complex wiring. Both methods can capture real-time conductor temperature changes. The duration of low-voltage bus voltage sags is acquired through a power quality monitoring terminal. This terminal integrates a voltage acquisition chip with a sampling rate of 10kHz, accurately recording the start and end times of voltage sags, calculating their duration, and simultaneously monitoring parameters such as voltage amplitude and frequency to aid in assessing voltage stability. User electricity priority is obtained from the power marketing system, which stores user profiles, labels user load levels according to industry standards, and connects to the power dispatch data network to obtain real-time priority classifications of users served by distribution transformers. Topological distances are obtained from the distribution network GIS system, which stores spatial data such as the geographical location of distribution transformers and line routes. The shortest path distance between the distribution transformer to be supplied and the target distribution transformer is extracted via an API interface, with an accuracy of ±10 meters. Actual load current is collected through low-voltage automation terminals (such as DTUs and FTUs). These terminals have built-in current transformers with a sampling accuracy of 0.2%, and upload the three-phase current on the low-voltage side of the distribution transformer in real time. Regarding timing control, parameter acquisition and medium-voltage side fault isolation steps are initiated synchronously. Upon receiving fault information on the medium-voltage side and triggering the isolation operation, the low-voltage side acquisition equipment begins operation simultaneously, avoiding parameter lag that fails to reflect real-time status. The acquisition frequency of once per second balances real-time performance with equipment power consumption, enabling timely capture of dynamic changes such as voltage dips and current fluctuations without increasing hardware burden due to high-frequency acquisition. In terms of data processing, the output formats of different devices are standardized after data acquisition. For example, the analog signal (4-20mA) output by the temperature sensor is converted into a numerical value, and the sag duration field is extracted from the JSON format data output by the power quality monitoring terminal to ensure that the subsequent distribution transformer set analysis module can directly call it and avoid data loss or incorrect parsing caused by incompatible formats.

[0049] The technical effects of the above embodiments include: clearly defining the equipment, timing and processing standards for parameter acquisition, ensuring reliable parameter sources, strong real-time performance and format compatibility, providing high-quality data for distribution set analysis and scheme generation, and improving the accuracy of subsequent steps.

[0050] The existing distribution transformer set lacks a clear screening logic and pre-verification process, which easily leads to the inclusion of distribution transformers without transfer conditions or with safety risks in the analysis. This results in redundant self-healing processes, low efficiency, and potential safety hazards.

[0051] Based on this, the steps for determining the distribution transformer set include: parsing the list of unpowered distribution transformers contained in the medium-voltage fault information, extracting the distribution transformer number, the distribution transformer to which it belongs, and the load type information to form a set of distribution transformers with low voltage; selecting distribution transformers with low-voltage automation terminals, available low-voltage tie switches, and normal communication channels from the set of distribution transformers with low voltage, excluding distribution transformers without low-voltage transfer conditions, to form a set of distribution transformers to be self-healed under low voltage; performing pre-verification on each distribution transformer to be self-healed under low voltage, including whether the distribution transformer is in a locked state, whether the low-voltage main switch is in the closed position, whether there is a fault signal on the low-voltage main switch, and whether the dynamic carrying capacity of the distribution transformer meets the basic load requirements, and including distribution transformers that meet all pre-verification conditions in the set of distribution transformers to be self-healed under low voltage.

[0052] This scheme clarifies the process for determining the distribution transformer set through a three-level screening logic. The core is to gradually eliminate distribution transformers without the conditions for power transfer and those at risk, ensuring the validity of subsequent analysis targets. In the stage of forming the undervoltage distribution transformer set, medium-voltage fault information includes a list of unenergized distribution transformers. Parsing this list extracts the transformer number, its associated transformer, and load type to form the undervoltage distribution transformer set, clarifying the initial analysis scope. The screening stage for self-healing distribution transformers focuses on the basic conditions for power transfer. The low-voltage automation terminal is the core hardware, requiring data acquisition and remote control functions; without a terminal, remote operation is impossible. Available low-voltage tie switches must be in the open state and free from mechanical and electrical faults, with normal closing capacity, serving as the physical channel for power transfer. A normal communication channel ensures command transmission and data feedback between the terminal and the master station; communication interruption renders control impossible. The absence of any of these three conditions results in the transformer being judged as lacking the conditions for power transfer and directly excluded from the undervoltage distribution transformer set, significantly reducing the scope of subsequent analysis. The pre-verification process for initiating a low-voltage self-healing distribution transformer cluster addresses safety and feasibility. The distribution transformers must be in an unlocked state; operation is prohibited in the locked state to prevent accidental activation. The low-voltage main switch must be in the closed position to ensure that faulty distribution transformers can be isolated via tripping operations, preventing fault propagation. The low-voltage main switch must have no fault signal to ensure normal operation. The dynamic load-bearing capacity of the distribution transformers must meet basic load requirements to avoid overload before power transfer. Only when all four conditions are met can a distribution transformer be included in the low-voltage self-healing distribution transformer cluster, ensuring that each distribution transformer possesses the prerequisite for safe self-healing.

[0053] The technical effects of the above embodiments include: through three-level screening and pre-verification, distribution transformers without transfer conditions and with safety risks are excluded, reducing invalid analysis processes, improving the accuracy of distribution transformer sets, and laying a reliable foundation for the subsequent generation of self-healing solutions.

[0054] The existing power transfer scheme search does not identify distribution transformer groups, the search range is boundless, and the number of alternative schemes is insufficient. This can easily lead to problems such as schemes not meeting topology conditions or having no alternatives after a single scheme fails, affecting the reliability of power restoration.

[0055] Based on this, the steps for searching low-voltage direct transfer schemes include: calling the distribution network low-voltage topology database to obtain the low-voltage tie switch connection relationship, conductor type, and power supply radius information of all distribution transformers in the self-healing distribution transformer set; dividing distribution transformers with direct low-voltage tie paths into the same distribution transformer group based on the tie switch connection relationship; searching for direct transfer schemes within each distribution transformer group, with search conditions including the low-voltage tie switch being in the open position, the low-voltage main switch of the opposite distribution transformer being in the closed position, the three-phase voltage of the low-voltage busbar of the opposite distribution transformer meeting the voltage standard, and the sum of the actual load current of the distribution transformer to be transferred and the current load current of the opposite distribution transformer not exceeding the initial threshold of the dynamic maximum allowable current of the opposite distribution transformer; and searching for at least two direct transfer schemes for each distribution transformer to be transferred, forming a candidate scheme library.

[0056] This scheme defines the search scope by identifying distribution transformer groups, clarifies the search conditions and the number of alternative solutions, and improves the rationality and reliability of power transfer schemes. The topology data retrieval step is fundamental. The distribution network low-voltage topology database stores the core topology information of all distribution transformers within the self-healing distribution transformer set. Among these, the low-voltage tie switch connection relationship records whether distribution transformers are directly connected via tie switches, which is crucial for distribution transformer group identification. The conductor type determines parameters such as the conductor's temperature coefficient and current carrying capacity, providing a basis for subsequent dynamic current calculations. The power supply radius is used to determine whether the power transfer path exceeds a reasonable range, avoiding excessive line loss that could lead to a decline in power quality. The distribution transformer group identification step, based on the tie switch connection relationship, uses a connectivity analysis algorithm to classify distribution transformers with direct low-voltage tie paths into the same distribution transformer group. For example, if distribution transformer A is connected to distribution transformer B, and distribution transformer B is connected to distribution transformer C, then A, B, and C belong to the same distribution transformer group. Distribution transformers within the same group have physical power transfer conditions, while distribution transformers across groups have no direct connection and do not require searching, significantly narrowing the search scope and improving efficiency. The search criteria ensure the feasibility and safety of the proposed solutions. The low-voltage tie switch is in the open position to allow for power transfer via closing; if it were closed, a new power transfer path could not be established. The low-voltage main switch of the opposite transformer is in the closed position to ensure that low-voltage power supply has been restored to the opposite transformer, providing power to the transformer awaiting transfer. The three-phase voltage of the low-voltage busbar of the opposite transformer meets the voltage standard, ensuring the power quality meets standards after transfer. The sum of the currents of the transformer awaiting transfer and the opposite transformer does not exceed the initial threshold of the opposite transformer's dynamic maximum allowable current, initially preventing overload. The alternative solution library construction requires searching for at least two suitable direct transfer solutions for each transformer awaiting transfer. For example, transformer A awaiting transfer can be transferred from transformer B or transformer C on the opposite side, forming an alternative library to prevent power interruption due to a single solution failing due to switch failure, load fluctuations, or other issues, leaving no alternative solution.

[0057] The technical effects of the above embodiments include: narrowing the search range by identifying distribution transformer groups, clarifying conditions to ensure the feasibility of the solution, avoiding the risk of single failure by multiple alternative solutions, and improving the search efficiency and power restoration reliability of power transfer solutions.

[0058] The existing transfer current limit uses the static rated current of the distribution transformer and does not take into account dynamic parameters such as conductor temperature and voltage sag. This results in the limit not matching the actual carrying capacity of the line, which can easily lead to overload tripping after the transfer.

[0059] Based on this, the dynamic maximum allowable current is calculated using the following formula:

[0060] ;

[0061] In the formula, This is the maximum allowable dynamic current of the transformer on the opposite side. This is the rated current of the low-voltage side of the transformer on the opposite side. The temperature coefficient of the conductor material in low-voltage lines. Real-time temperature of the conductor. The reference temperature for the conductor. This is the line loss correction factor for low-voltage lines. The actual load current of the distribution transformer to be transferred. This refers to the duration of the low-voltage bus voltage dip. This is the rated voltage of the low-voltage busbar. For the apparent capacity of the transformer on the opposite side, It is a natural constant.

[0062] This solution constructs a dynamic current limit model using an original formula, integrating multiple parameters such as temperature, voltage sag, and load to ensure that the limit closely matches the actual carrying capacity of the line. The definitions, dimensions, and logical relationships of each parameter in the formula are clearly defined. The core output, measured in amperes (A), reflects the maximum current that the low-voltage side of the opposite distribution transformer can carry in real time, and is a key basis for verifying the power transfer scheme. This is the rated current on the low-voltage side of the transformer, in amperes (A), derived from the transformer nameplate, and serves as the basic reference value for dynamic limits. Temperature coefficient of conductor material, expressed in 1 / ℃ (rate of change of resistance per degree Celsius), for copper conductors. The value is 0.003931 / ℃, and for aluminum wire it is 0.004291 / ℃. This is used to correct for the effect of temperature on wire resistance—resistance increases with increasing temperature, and current carrying capacity decreases. Therefore, in the formula... Xiang Sui Increase and decrease, decrease . This is the reference temperature for the conductor, in °C, with a default value of 25 °C. It is the reference temperature corresponding to the rated resistance of the conductor, ensuring a consistent reference for temperature correction. This is a line loss correction factor, dimensionless, and positively correlated with the conductor cross-sectional area, such as a 120mm² conductor. The value is 0.85 for 70mm² conductors and 0.92 for 70mm² conductors, used to correct for differences in line loss between different conductors; The actual load current of the distribution transformer to be supplied is expressed in Am, reflecting the size of the load to be supplied. The duration of the low-voltage bus voltage dip, in seconds (s), is the duration during which the voltage is below 198V, affecting line loss and switch reliability. This is the rated voltage of the low-voltage busbar, in volts (V), default 220V; The apparent capacity of the transformer on the opposite side is expressed in kilovolt-amperes (kVA), reflecting the overall capacity of the transformer. The overall correction factor addresses the impact of line loss and voltage sag on load-carrying capacity. or As the value increases, this term decreases, further reducing the overall value. . It is the natural constant (approximately 2.718). The item is an additional correction for the impact of voltage sag on switch reliability. The reliability of the switch action decreases over time, and further reduction is needed. To allow for a safety margin, ensure that the line will not be overloaded even if the switching action is delayed.

[0063] The technical effects of the above embodiments include: dynamically adjusting the current limit, solving the problem that the static rated current does not match the actual carrying capacity, avoiding overload tripping caused by temperature rise and voltage drop after power transfer, and improving power transfer safety.

[0064] The existing power transfer scheme prioritizes users based solely on transformer load rate, without considering user power priority, topology distance, or other factors. This results in delays in power restoration for high-priority users, which does not comply with the power supply principle of "prioritizing the restoration of important loads."

[0065] Based on this, the priority coefficient is calculated using the following formula:

[0066] ;

[0067] In the formula, This is the priority coefficient for the power conversion scheme. The priority weight of electricity consumption for users connected to the distribution transformer to be transferred. For the load rate of the distribution transformer to be transferred and , This is the maximum allowable dynamic current of the transformer on the opposite side. The actual load current of the distribution transformer to be transferred. This refers to the topological distance between the distribution transformer to be transferred and the distribution transformer on the opposite side. The number of high-priority users connected to the distribution transformer awaiting transfer. The total number of users served by the distribution transformer to be transferred; sort the direct transfer schemes in the alternative scheme library from largest to smallest according to the priority coefficient, and select the scheme ranked first as the target transfer scheme.

[0068] This scheme achieves a reasonable ranking of transfer schemes through a priority formula that couples multiple factors. The core is to take into account the importance of users, the security of the system, and the efficiency of transfer. The definitions, dimensions, and logical relationships of each parameter in the formula are clear. This is a priority coefficient, dimensionless, with a value range of 0 to 1.2. The larger the value, the higher the priority of the scheme, and it is the direct basis for ranking. Electricity priority weights for users are dimensionless and set according to load level—Level 1 loads include hospitals and emergency command centers. =1.0, Level 2 load, commercial center, important industry =0.7, Level 3 load, ordinary residential =0.3, directly reflecting the importance of users and ensuring that the solutions of high-priority users are given priority. The load factor of the distribution transformer to be transferred is dimensionless. (Actual load current of the transformer to be transferred, in A) and (Rated current of the transformer to be supplied, in A) Calculated as follows ( ), This reflects the remaining load capacity of the distribution transformer to be transferred. The stronger the remaining capacity, the larger this value, and the higher the priority of the scheme, so as to avoid selecting distribution transformers that are already fully loaded for transfer. The maximum allowable dynamic current (in A) of the distribution transformer on the opposite side. The actual load current (in A) of the transformer to be transferred to the distribution transformer. The dimensionless ratio indicates that the opposite transformer has a greater capacity to carry the load to be transferred. The square term strengthens the influence of this factor and ensures the selection of a scheme with safe load-bearing capacity. The topological distance between the transformer to be transferred and the transformer on the opposite side is expressed in kilometers (km). Dimensionless, the closer the distance, the larger the value of this item, the higher the priority of the solution, and the less the transfer line loss and power restoration time. The farther the distance, the greater the line loss and the longer the power restoration time. Number of high-priority users connected to the distribution transformer to be transferred (unit: households). The total number of users connected to the distribution transformer to be transferred (unit: users). The percentage of high-priority users is dimensionless, and 0.08 is the weighting coefficient for this factor. This further strengthens the priority of the concentrated allocation of resources to high-priority users and avoids overlooking the needs of a group due to a single weight. The calculation involves first determining the values ​​of each parameter and then substituting them into the formula. The options in the alternative solution library are categorized as follows: The power supply is sorted in descending order, and the first option is the target power transfer option, ensuring that the sorting logic matches the actual power supply needs.

[0069] The technical effects of the above embodiments include: realizing multi-dimensional priority ranking of power transfer schemes, ensuring that schemes for high-priority users, sufficient capacity, and short distances are executed first, solving the problem of power restoration delay for high-priority users, and improving the quality of power supply services.

[0070] In the current multi-to-one power flow verification mode, the actual load current of the distribution transformer to be transferred is directly summed without considering the load fluctuation caused by the transfer delay. This can easily cause the total equivalent load to exceed the dynamic limit of the distribution transformer on the other side, leading to overload.

[0071] Based on this, the power flow verification in the multi-to-one mode is calculated using the following formula:

[0072] ;

[0073] In the formula, for The total equivalent load current of the power supply transformer to be transferred to the station. For the first The actual load current of the distribution transformer awaiting transfer. For the first The adaptive adjustment coefficient of the distribution transformer to be transferred to the platform and , For the first Taiwan's supply transfer and distribution delay time. The maximum allowable dynamic current of the target power supply transformer; if the total equivalent load current exceeds Then, the transformers to be transferred to the distribution system are eliminated in order of priority coefficient from low to high until the verification conditions are met.

[0074] This solution achieves accurate load verification in the multi-to-one mode by introducing a verification formula with an adaptive adjustment coefficient. The core is to correct load fluctuations caused by power transfer delays. The definitions, dimensions, and verification logic of each parameter in the formula are clear. for The total equivalent load current of the distribution transformer to be transferred, in amperes (A), is the core calculation value for verification, reflecting the actual equivalent load that the target distribution transformer needs to bear after the transfer. For the first The actual load current of the transformer waiting to be transferred to the power distribution station, in amperes (A), is collected by the low-voltage automation terminal and is the basic data for load calculation. For the first The adaptive adjustment coefficient of the distribution transformer awaiting power transfer is dimensionless and used to correct for load changes caused by power transfer delays. During the power transfer delay period, the load of the distribution transformer awaiting power transfer may fluctuate due to user electricity consumption behaviors (such as motor starting and equipment switching). The longer the delay, the higher the risk of fluctuations. Depend on (No. The power transfer delay time of the distribution transformer waiting to transfer power, in seconds (s), i.e., the time from the issuance of the power transfer command to the closing of the tie switch. Calculations show that The longer, The smaller the value, the lower the corresponding equivalent load, and the more safety margin is reserved for fluctuations. The value is a natural constant (approximately 2.718), and 0.05 is the delay effect coefficient, which was determined through numerous experiments to ensure that the correction range closely matches the actual load fluctuation pattern. The dynamic maximum allowable current of the target distribution transformer, in amperes (A), represents the maximum current that the target distribution transformer can carry in real time, providing a safety threshold for verification. Regarding the verification process, the first step is to obtain... Taiwan awaits transfer of distribution change and Calculate the cost of each machine Then calculate the cost for each machine. Sum the results to obtain the total equivalent load current; then sum the total equivalent load current with... In comparison, if the total equivalent load current is ≤ If the total equivalent load current is greater than 1, then the solution meets the safety requirements; if the total equivalent load current is greater than 1, then the solution meets the safety requirements. Then according to (Priority coefficient) Eliminate power supply and distribution transformers to be transferred from low to high. Recalculate the total equivalent load current for each transformer eliminated, until the total equivalent load current is ≤ This ensures that the target distribution transformer will not be overloaded after the power supply is switched.

[0075] The technical effects of the above embodiments include: accurately verifying the total equivalent load in the multi-to-one mode, correcting load fluctuations caused by transfer delays, preventing the total load from exceeding the dynamic limit, solving the overload problem caused by traditional direct summation, and improving transfer security.

[0076] The lack of modules in the medium and low voltage collaborative self-healing system and the unclear interaction between modules make it impossible to achieve multi-parameter collaborative self-healing, resulting in low system power restoration efficiency and poor reliability.

[0077] Based on this, the system includes a medium-voltage self-healing interaction module, a multi-dimensional parameter acquisition module, a distribution transformer analysis module, a low-voltage power transfer decision module, and an execution control module. The medium-voltage self-healing interaction module receives medium-voltage permanent fault information and medium-voltage self-healing action results, and outputs medium-voltage fault information to the distribution transformer analysis module. The multi-dimensional parameter acquisition module is electrically connected to the medium-voltage self-healing interaction module, acquires low-voltage side parameters, standardizes them, and outputs them to the distribution transformer analysis module. The distribution transformer analysis module is electrically connected to the multi-dimensional parameter acquisition module, and after completing the distribution transformer set analysis, outputs the activation of the self-healing distribution transformer set to the low-voltage power transfer decision module. The low-voltage power transfer decision module is electrically connected to the distribution transformer analysis module, generates a power transfer scheme, and outputs it to the execution control module. The execution control module is electrically connected to the low-voltage power transfer decision module, executes the power transfer scheme, and triggers parameter re-acquisition when the switch fails.

[0078] This system constructs a complete hardware architecture for medium- and low-voltage collaborative self-healing by clearly defining the functions and electrical connections of five core modules, achieving closed-loop control of data acquisition, analysis, decision-making, and execution. The medium-voltage self-healing interaction module serves as the interface between the system and the medium-voltage side. It integrates a communication interface to receive permanent fault information and medium-voltage self-healing action results from medium-voltage protection devices and monitoring and control devices. This module parses and filters the received information, extracting medium-voltage fault information related to low-voltage self-healing, and transmits it to the distribution transformer analysis module via electrical connections. This provides basic medium-voltage side data for low-voltage distribution transformer analysis, avoiding blind analysis on the low-voltage side. The multi-dimensional parameter acquisition module is the low-voltage side data source, electrically connected to the medium-voltage self-healing interaction module. It integrates sensor interfaces, system docking interfaces, and data processing units. Through the system docking interface, it acquires user power priority and topology distance. After standardization processing by the data processing unit, it transmits the data to the distribution transformer analysis module via electrical connections, providing comprehensive and compatible low-voltage parameters for subsequent analysis. The distribution transformer analysis module is the core of the distribution transformer set screening. Electrically connected to the multi-dimensional parameter acquisition module, it integrates a processor and memory in its hardware. After receiving medium-voltage fault information and low-voltage parameters, this module executes logic for analyzing the undervoltage distribution transformer set, screening the set of distribution transformers awaiting self-healing, and pre-verifying the set of self-healing distribution transformers. It generates a set of self-healing distribution transformers to be activated and transmits this data to the low-voltage power transfer decision module via electrical connection, excluding invalid distribution transformers. The low-voltage power transfer decision module is the core of the scheme generation. Electrically connected to the distribution transformer analysis module, it integrates a high-performance processor in its hardware. After receiving the set of self-healing distribution transformers to be activated, this module executes logic for topology analysis, power transfer scheme search, scheme priority ranking, and power flow verification, generating the final power transfer scheme. This scheme is then transmitted to the execution control module via electrical connection to ensure the scheme's safety and priority. The execution control module is the core of the scheme execution and dynamic adjustment. It is electrically connected to the low-voltage power transfer decision module and integrates a remote control unit and a feedback unit in hardware. After receiving the power transfer scheme, this module sends remote control commands to control the operation of the low-voltage tie switch and the main switch, and at the same time receives the switch operation feedback signal. If the feedback switch fails, it immediately triggers the multi-dimensional parameter acquisition module to re-acquire parameters through electrical connection, drives the low-voltage power transfer decision module to update the scheme, realizes closed-loop control, and avoids power interruption.

[0079] The technical effects of the above embodiments include: constructing a complete medium- and low-voltage collaborative self-healing hardware architecture, clarifying module functions and interactions, realizing multi-parameter collaboration and dynamic adjustment, solving the problem of low power restoration efficiency caused by missing modules and ambiguous interactions, and improving system reliability.

[0080] The existing multi-dimensional parameter acquisition module lacks subdivided functional units, and the parameter acquisition equipment and data transmission protocols are unclear, resulting in incomplete parameter acquisition and asynchronous data transmission, which affects the accuracy of subsequent module analysis.

[0081] Based on this, the multi-dimensional parameter acquisition module includes a temperature acquisition unit, a power quality monitoring unit, a user information interaction unit, and a topology data acquisition unit. The temperature acquisition unit acquires conductor temperature, the power quality monitoring unit acquires voltage sag duration, the user information interaction unit acquires user power priority, and the topology data acquisition unit acquires topology distance. Each unit is electrically connected to the distribution transformer analysis module and uses a unified data transmission protocol to synchronously transmit parameters, ensuring data real-time performance and consistency. The temperature acquisition unit supports uploading data from multiple measurement points, and the power quality monitoring unit can generate power quality analysis reports.

[0082] This module is divided into four main functional units, clearly defining the data acquisition content, transmission standards, and additional functions of each unit to ensure comprehensive parameter acquisition and reliable transmission. The temperature acquisition unit is the source of conductor temperature data. Hardware-wise, it employs distributed fiber optic temperature sensors or wireless temperature sensors. The distributed fiber optic sensors are laid along the entire low-voltage line, using optical time-domain reflectometry (OTDR) technology to achieve continuous temperature monitoring at one measurement point every 500 meters, with a measurement range of -50 to 150℃ and an accuracy of ±0.5℃. It supports parallel uploading of data from multiple measurement points, comprehensively capturing temperature changes in different sections of the line. The wireless temperature sensors use ZigBee or LoRa protocols and are installed at key locations such as conductor joints and branches, avoiding complex wiring. Both types of sensors process the acquired signals through signal conditioning circuits to ensure accurate temperature data. This unit transmits the temperature data to the transformer analysis module via electrical connection, providing temperature parameters for dynamic current calculations. The power quality monitoring unit is the source of voltage sag data. Hardware-wise, it integrates voltage acquisition and data processing chips, enabling real-time acquisition of the three-phase voltage of the low-voltage bus. It records the start and end times of sags based on voltage amplitude, calculates the duration, and simultaneously monitors parameters such as voltage RMS value, frequency, and harmonic content. This unit generates a power quality analysis report and transmits the sag duration and analysis report to the distribution transformer analysis module via electrical connection, providing a basis for switch reliability assessment and dynamic current correction. The user information interaction unit is the source of user priority data. Hardware-wise, it integrates an Ethernet interface or 4G module, connecting to the power marketing system via the power dispatch data network to obtain information such as the load level (Level 1 / Level 2 / Level 3), user name, and electricity address of users served by the distribution transformer. This ensures that priority data is consistent with the marketing system and avoids manual entry errors. This unit transmits user electricity priority to the distribution transformer analysis module via electrical connection, providing user importance parameters for distribution transformer set screening and scheme ranking. The topology data acquisition unit is the source of topology distance data. It integrates a standard API interface on the hardware, interfacing with the distribution network GIS system to extract the geographic coordinates of the transformers to be transferred and the target transformers. It calculates the shortest path distance between them using a distance calculation formula, with an accuracy of ±10 meters. This unit transmits the topology distance to the transformer analysis module via electrical connection, providing distance parameters for transformer group identification and scheme ranking. All units are electrically connected to the transformer analysis module, using the unified IEC61850-9-2 data transmission protocol to ensure data transmission latency is less than 1 second. Furthermore, all parameters have consistent timestamps to avoid data asynchrony caused by different protocols or timestamp differences, ensuring the accuracy of subsequent analysis.

[0083] The technical effects of the above embodiments include: subdividing the parameter acquisition units, clarifying the functions and transmission standards of each unit, realizing comprehensive parameter acquisition and synchronous transmission, solving the problems of incomplete acquisition and data asynchrony, and providing high-quality data support for subsequent modules.

[0084] The existing low-voltage power transfer decision module lacks subdivided functional units, and the logic for topology analysis, scheme ranking, and power flow verification is vague. There are no clear interfaces for data transfer between modules, resulting in low efficiency and poor accuracy in generating power transfer schemes, which cannot meet safety and priority requirements.

[0085] Based on this, the low-voltage power transfer decision module includes a topology analysis unit, a scheme ranking unit, and a verification unit. The topology analysis unit identifies the distribution transformer group and outputs the result to the scheme ranking unit. The scheme ranking unit calls the priority coefficient model to rank the power transfer schemes and outputs the result to the verification unit. The verification unit calls the power flow verification model to calculate the total equivalent load current, eliminates distribution transformers that do not meet the conditions, and generates the final power transfer scheme. The topology analysis unit, scheme ranking unit, and verification unit are electrically connected in sequence and transmit data in real time through internal interfaces to ensure that the scheme meets the safety and power restoration priority requirements.

[0086] This module, by subdividing into three major functional units and clarifying the logic and data transmission relationships of each unit, achieves efficient and accurate generation of power transfer schemes. Its core is the step-by-step completion of topology definition, scheme optimization, and safety verification. The topology analysis unit is the core of transformer group identification. Hardware-wise, it integrates a processor and a topology database, and incorporates a connectivity analysis algorithm based on depth-first search. After receiving the self-healing transformer set from the transformer analysis module, this unit loads the tie switch connection relationships from the distribution network low-voltage topology database, such as transformer A - tie switch 1 - transformer B. Through the algorithm, it traverses all the tie paths of the transformers, grouping transformers with direct tie paths into the same transformer group. For example, if transformer A is connected to B and B is connected to C, then A, B, and C are grouped together. Simultaneously, it labels the available tie switches and conductor types for each transformer within the group, forming transformer group information. This unit transmits the transformer group information to the scheme sorting unit in real time via an internal high-speed electrical interface, defining the scope of the scheme search. The scheme ranking unit is the core of scheme optimization. It integrates an FPGA chip and has a built-in priority coefficient calculation model. After receiving information from the distribution transformer group, this unit searches for suitable direct-to-electricity conversion schemes for each distribution transformer to be converted within the group, forming a candidate scheme library. Simultaneously, it obtains user electricity priority from the multi-dimensional parameter acquisition module. ), topological distance ( Actual load current () The maximum allowable dynamic current of the transformer on the opposite side can be obtained from the formula. ), calculate the alternative solution (Priority coefficient); by Sort the alternative solutions in descending order to form a ranked list of solutions (including solution details). The unit transmits the sorting scheme list to the verification unit in real time through an internal interface, ensuring that high-priority schemes enter the verification process first. The verification unit is the core of scheme security verification, integrating a high-performance processor (such as Intel Xeon) and a built-in power flow verification model. After receiving the sorting scheme list, this unit extracts the actual load current of each transformer to be transferred for the "multiple-to-one" mode scheme. ) and transfer delay time ( (Based on historical data from the execution control module), calculate the adaptive adjustment coefficient for each unit ( ) and total equivalent load current ( ); Obtain the dynamic maximum allowable current of the target power supply transformer ( ), compare the total equivalent load current with If the total equivalent load current is ≤ If the total equivalent load current is greater than 100%, then the solution meets the safety requirements and is determined as the final power transfer solution; if the total equivalent load current is greater than 100%, then the solution meets the safety requirements and is determined as the final power transfer solution. Then sort the list according to the sorting scheme. The system eliminates power transfer transformers from low to high load, recalculating the total equivalent load current for each removed transformer until safety requirements are met. Simultaneously, a verification report is generated, and the final power transfer scheme and report are transmitted to the execution control module via an internal interface. The three units are electrically connected sequentially, using a high-speed serial bus for data transmission at a rate ≥100Mbps. This ensures a seamless scheme generation process, with the total time from topology analysis to final scheme output being <5 seconds, and each step prioritizing power restoration. ) and safety ( ), to avoid neglecting one aspect for another.

[0087] The technical effects of the above embodiments include: subdividing the power transfer decision-making units, clarifying the logic and data transmission of each unit, realizing efficient sorting and security verification of the solutions, solving the problems of low efficiency and poor accuracy in solution generation, and ensuring that the solutions meet the requirements of security and power restoration priority.

[0088] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0089] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A method for medium and low voltage collaborative self-healing for fast power restoration for global users, characterized in that, The method comprises the following steps: S1, receiving medium voltage permanent fault information, performing fault positioning on the medium voltage side, remotely controlling the isolation of the fault area, and remotely controlling the power restoration of the non-fault area on the medium voltage side; S2, collecting the real-time temperature of the low-voltage conductor, the voltage sag duration of the low-voltage bus, the user power priority of the distribution transformer, the topology distance between the standby distribution transformer and the target distribution transformer, and the actual load current of the standby distribution transformer, and realizing dynamic load checking of the low-voltage power supply of the distribution transformer; S3, based on the medium voltage permanent fault information and the above-mentioned collected parameters, for the fault area, determining the set of voltage loss distribution transformers, performing low-voltage self-healing start boundary checking of the voltage loss distribution transformers, and determining the set of low-voltage self-healing distribution transformers; S4, performing low-voltage topology analysis on the set of low-voltage self-healing distribution transformers to identify the connected distribution transformer groups, searching for low-voltage direct transfer power supply schemes in units of distribution transformer groups; S5, performing priority sorting and power flow checking on the direct transfer power supply scheme, and realizing low-voltage automatic transfer of the voltage loss distribution transformers through low-voltage self-healing to restore the power supply of the low-voltage users in the distribution transformers in the fault area; S6, executing the transfer scheme according to the order of the distribution transformer groups and the priority descending order of the distribution transformer groups, if the switch remote control fails, re-collecting the above-mentioned parameters and updating the low-voltage transfer scheme until the power supply of all users is restored.

2. The method of claim 1, wherein the method further comprises: S2 specifically includes: the real-time temperature of the conductor is obtained by a temperature sensor, the voltage sag duration of the low-voltage bus is obtained by a power quality monitoring terminal, the user power priority is obtained from a power marketing system, the topology distance is obtained from a distribution network GIS system, and the actual load current is obtained by a low-voltage automation terminal; the parameter collection process is started synchronously with the fault isolation step on the medium voltage side, and the collection frequency is set to 1 per second to ensure the timeliness of the parameters; after collection, the parameters are standardized and converted into a numerical format that can be recognized by the system for subsequent distribution transformer set analysis.

3. The method of claim 2, wherein the method further comprises: S3 specifically includes: analyzing the list of non-restored distribution transformers contained in the medium voltage fault information, extracting the distribution transformer number, the distribution transformer it belongs to, and the load type information to form the set of voltage loss distribution transformers; selecting distribution transformers with low-voltage automation terminals, available low-voltage tie switches, and normal communication channels from the set of voltage loss distribution transformers, excluding distribution transformers without low-voltage transfer conditions to form the set of low-voltage self-healing distribution transformers; pre-checking each low-voltage self-healing distribution transformer, which includes whether the distribution transformer is in a locked state, whether the low-voltage main switch is in a closed position, whether there is a fault signal in the low-voltage main switch, and whether the dynamic load capacity of the distribution transformer meets the basic load requirement, and all pre-checked distribution transformers are included in the set of low-voltage self-healing distribution transformers.

4. The method of claim 3, wherein the method further comprises: In S4, the step of searching for a low-voltage direct transfer power supply scheme includes: calling a low-voltage topology database of network distribution, obtaining connection relationship of low-voltage tie switches, wire type and power supply radius information of all distribution transformers in the starting self-healing distribution transformer set; based on the connection relationship of the tie switches, the distribution transformers with direct low-voltage tie paths are divided into the same distribution transformer group; searching for a direct transfer power supply scheme in each distribution transformer group, and the search conditions include that the low-voltage tie switch is in the open position, the low-voltage main switch of the opposite side distribution transformer is in the closed position, the three-phase voltage of the low-voltage bus of the opposite side distribution transformer meets the voltage standard, and the sum of the actual load current of the to-be-converted distribution transformer and the current load current of the opposite side distribution transformer is less than the initial threshold of the dynamic maximum allowable current of the opposite side distribution transformer; at least two direct transfer power supply schemes are searched for each low-voltage to-be-converted distribution transformer, and a candidate scheme library is formed.

5. The method of claim 4, wherein, The dynamic maximum allowable current is calculated by the following formula: ； In the formula, is the dynamic maximum allowable current of the opposite transformer, is the low-voltage side rated current of the opposite transformer, is the temperature coefficient of the low-voltage line conductor material, is the real-time temperature of the conductor, is the reference temperature of the conductor, is the line loss correction coefficient of the low-voltage line, is the actual load current of the transformer to be switched, is the duration of the low-voltage bus voltage sag, is the rated voltage of the low-voltage bus, is the apparent capacity of the opposite transformer, is the natural constant.

6. The method of claim 1, wherein the method further comprises: In S5, the priority sorting includes calculating a priority coefficient, and sorting the priority coefficient, the priority coefficient is calculated by the following formula: ； In the formula, is the priority coefficient of the transfer solution, is the power consumption priority weight of the users of the to-be-transferred power supply and distribution transformer, is the load rate of the to-be-transferred power supply and distribution transformer, and , is the dynamic maximum allowable current of the opposite power supply and distribution transformer, is the actual load current of the to-be-transferred power supply and distribution transformer, is the topological distance between the to-be-transferred power supply and distribution transformer and the opposite power supply and distribution transformer, is the number of high-priority users of the to-be-transferred power supply and distribution transformer, is the total number of users of the to-be-transferred power supply and distribution transformer; the direct transfer solution in the candidate solution library is sorted according to the priority coefficient from large to small, and the solution at the top of the sorting is selected as the target transfer solution.

7. The method of claim 6, wherein the method further comprises: In S5, the power flow check is calculated by the following formula: ； In the formula, is the total equivalent load current of the standby power supply and distribution transformer, is the first the actual load current of the standby power supply and distribution transformer, is the first the adaptive adjustment coefficient of the standby power supply and distribution transformer, and , is the first the transfer delay time of the standby power supply and distribution transformer, is the dynamic maximum allowable current of the target power supply and distribution transformer; if the total equivalent load current exceeds , the standby power supply and distribution transformer is removed according to the priority coefficient from low to high until the check condition is met.

8. A medium and low voltage collaborative self-healing system for global user fast power restoration, applied to the medium and low voltage collaborative self-healing method for global user fast power restoration according to any one of claims 1-7, characterized in that, The medium-voltage self-healing interaction module is used for receiving medium-voltage permanent fault information and medium-voltage self-healing action results, and outputting medium-voltage fault information to the distribution transformer analysis module; the multi-dimensional parameter acquisition module is electrically connected with the medium-voltage self-healing interaction module, acquires low-voltage side parameters, and outputs the low-voltage side parameters to the distribution transformer analysis module after standardized processing; the distribution transformer analysis module is electrically connected with the multi-dimensional parameter acquisition module, outputs a starting low-voltage self-healing distribution transformer set to the low-voltage transfer decision module after completing distribution transformer set analysis; the low-voltage transfer decision module is electrically connected with the distribution transformer analysis module, outputs a transfer scheme to the execution control module after generating the transfer scheme; and the execution control module is electrically connected with the low-voltage transfer decision module, executes the transfer scheme and triggers parameter reacquisition when switch failure occurs.

9. The medium and low voltage collaborative self-healing system for fast power recovery of global users according to claim 8, characterized in that, The multi-dimensional parameter acquisition module includes a temperature acquisition unit, a power quality monitoring unit, a user information interaction unit and a topology data acquisition unit; the temperature acquisition unit acquires wire temperature, the power quality monitoring unit acquires voltage sag duration, the user information interaction unit acquires user power consumption priority, and the topology data acquisition unit acquires topology distance; each unit is electrically connected with the distribution transformer analysis module, adopts a unified data transmission protocol to synchronously transmit parameters, and ensures data real-time performance and consistency; the temperature acquisition unit supports multi-measurement-point data uploading, and the power quality monitoring unit can generate a power quality analysis report.

10. The medium and low voltage collaborative self-healing system for fast power recovery of global users according to claim 9, characterized in that, The low-voltage transfer decision module includes a topology analysis unit, a scheme sorting unit and a checking unit; the topology analysis unit identifies distribution transformer groups and outputs the distribution transformer groups to the scheme sorting unit; the scheme sorting unit sorts the transfer scheme by calling a priority coefficient model and outputs the transfer scheme to the checking unit; the checking unit calculates total equivalent load current by calling a power flow checking model, eliminates distribution transformers that do not meet the conditions, and generates a final transfer scheme; the topology analysis unit, the scheme sorting unit and the checking unit are sequentially electrically connected, transmit data in real time through internal interfaces, and ensure that the scheme meets safety and power restoration priority requirements.

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