High breaking capacity adaptive protection control method and device for low-voltage distribution system

Abstract

This invention discloses a high-breaking-capacity adaptive protection control method and device for low-voltage power distribution systems. The method acquires topology operation data, protection device parameters, circuit breaker health status data, environmental status data, and load importance data of the target low-voltage power distribution system. First, it constructs a dynamic equivalent impedance network based on the current operating mode and determines the expected fault current of candidate fault points. Then, it combines the rated breaking capacity of the protection device, the actual health degradation state, and the operating environment to obtain the current actual effective breaking capacity. Next, it determines the breaking capacity margin based on the matching relationship between the expected fault current and the actual effective breaking capacity, and combines the fault thermal shock energy and the selectivity relationship between upper and lower level protections to form a breaking risk index. Finally, it generates protection action parameters and a linkage control strategy, thereby improving the fault clearing reliability of the low-voltage power distribution system under conditions of high short-circuit current levels and changing operating modes.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a high-breaking-capacity adaptive protection control method and device for low-voltage power distribution systems. Background Technology

[0002] Low-voltage power distribution systems are typically located at the end of the power distribution chain and are characterized by a large number of branches, multiple protection levels, complex load types, and frequent changes in operating modes. With the integration of large-capacity distribution transformers, distributed photovoltaic systems, energy storage, charging pile clusters, high-power motor loads, and data center loads, the short-circuit current level, fault current direction, and protection coordination relationships of low-voltage power distribution systems have all undergone significant changes. Traditional low-voltage protection methods are usually based on static settings of the circuit breaker's rated current, instantaneous trip threshold, short-delay trip threshold, long-delay protection curve, and nameplate short-circuit breaking capacity. These settings can meet general protection requirements when the system operation is basically stable and the circuit breakers are in good condition.

[0003] Existing technologies include solutions that block protection when the short-circuit current exceeds the circuit breaker's breaking capacity, waiting for the upstream circuit breaker to disconnect part of the fault current. However, these solutions typically do not translate the circuit breaker's health status into its actual effective breaking capacity, making it difficult to guarantee the reliability of high breaking capacity protection in low-voltage power distribution systems. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a high-breaking-capacity adaptive protection control method and device for low-voltage power distribution systems.

[0005] The technical solution of this invention is as follows: This invention provides a high breaking capacity adaptive protection control method for low-voltage power distribution systems, the method comprising: Acquire multi-source status data of the target low-voltage power distribution system, including topology operation data, protection device parameters, circuit breaker health status data, environmental status data, and load importance data; Based on the topology operation data, a dynamic equivalent impedance network of the target low-voltage power distribution system is constructed, and based on the dynamic equivalent impedance network, the expected fault current of the preset candidate fault point under the current operation mode is determined. Based on the protection device parameters, the circuit breaker health status data, and the environmental status data, the rated breaking capacity of the protection device is dynamically corrected to obtain the actual effective breaking capacity of the protection device under the current operating state. Based on the expected fault current and the actual effective breaking capacity, the breaking capacity margin of the protection device for the candidate fault point is determined, and combined with the fault thermal shock energy corresponding to the candidate fault point and the selectivity relationship between the upper and lower level protection, the breaking risk index corresponding to the protection device is determined. Based on the tripping risk index, the selectivity relationship between upper and lower level protections, and the load importance data, protection action parameters and linkage control strategies are generated. The linkage control strategy is used to maintain the lower level protection with priority when the tripping capacity margin of the protection device meets the preset safe tripping conditions, and to execute at least one of the following when the tripping capacity margin of the protection device does not meet the safe tripping conditions: upper level backup protection, current limiting control, distributed power supply current limiting, interruptible load shedding, and topology adjustment. Based on the protection action parameters and the linkage control strategy, adaptive protection control is performed on the target low-voltage power distribution system.

[0006] Preferably, the step of constructing a dynamic equivalent impedance network of the target low-voltage power distribution system based on the topology operation data, and determining the expected fault current of a preset candidate fault point under the current operating mode based on the dynamic equivalent impedance network, includes: Based on the topology operation data, the connection relationships and conduction status between the low-voltage busbars, feeder branches, protection devices, load nodes, bus tie switches, tie switches, and controllable power access points in the target low-voltage power distribution system are determined. Based on the connection relationship and the conduction state, a dynamic equivalent impedance network is constructed to characterize the fault current propagation path under the current operating mode; In the dynamic equivalent impedance network, the set of conducting branches between the power supply equivalent point and the candidate fault point is determined, and the equivalent impedance corresponding to the candidate fault point is determined based on the branch impedance in the set of conducting branches, the power supply equivalent impedance, and the local connection impedance corresponding to the candidate fault point. Based on the equivalent impedance, operating voltage, and fault transition impedance corresponding to the candidate fault point, determine the basic fault current of the candidate fault point under the current operating mode; Based on the controllable power supply access status that is electrically connected to the candidate fault point in the dynamic equivalent impedance network, the basic fault current is corrected to obtain the expected fault current of the candidate fault point under the current operating mode.

[0007] Preferably, the step of correcting the basic fault current based on the controllable power supply access status that has an electrical connection relationship with the candidate fault point in the dynamic equivalent impedance network to obtain the expected fault current of the candidate fault point under the current operating mode includes: In the dynamic equivalent impedance network, a controllable power source that has a conductive electrical connection with the candidate fault point is identified. The controllable power source includes at least one of distributed power source and energy storage. The contribution of the controllable power supply to the fault current of the candidate fault point is determined based on the electrical distance between the controllable power supply and the candidate fault point. Based on the basic fault current and the contribution of the fault current, the expected fault current of the candidate fault point under the current operating mode is determined.

[0008] Preferably, the step of dynamically correcting the rated breaking capacity of the protection device based on the protection device parameters, the circuit breaker health status data, and the environmental status data to obtain the actual effective breaking capacity of the protection device under the current operating state includes: Based on the parameters of the protection device, determine the rated ultimate short-circuit breaking capacity and the rated operational short-circuit breaking capacity of the protection device, and determine the basic breaking capacity of the protection device based on the rated ultimate short-circuit breaking capacity and the rated operational short-circuit breaking capacity. Based on the circuit breaker health status data, determine the health status correction coefficient of the protection device caused by at least one of contact wear, short circuit breaking count, contact resistance, terminal temperature rise, and operating mechanism operation status. Based on the environmental condition data, determine the environmental correction factor of the protection device caused by at least one of the following: cabinet temperature, humidity, dust pollution level, and heat dissipation status. Based on the basic breaking capacity, the health status correction coefficient, and the environmental correction coefficient, the rated breaking capacity of the protection device is dynamically corrected to obtain the actual effective breaking capacity of the protection device under the current operating state.

[0009] Preferably, determining the breaking capacity margin of the protection device for the candidate fault point based on the expected fault current and the actual effective breaking capacity, and determining the breaking risk index corresponding to the protection device in conjunction with the fault thermal shock energy corresponding to the candidate fault point and the selectivity relationship between upper and lower level protections, includes: The breaking capacity margin of the protection device for the candidate fault point is determined based on the difference between the actual effective breaking capacity of the protection device in the current operating state and the expected fault current of the candidate fault point. The thermal shock energy corresponding to the candidate fault point is determined based on the expected fault current of the candidate fault point and the predicted operating time of the protection device for the candidate fault point. Based on the health status correction coefficient and environmental correction coefficient of the protection device, the ultimate thermal shock withstand capability of the protection device under the current operating state is determined, and the thermal shock margin is determined based on the fault thermal shock energy and the ultimate thermal shock withstand capability. Based on the aforementioned protection selectivity relationship between upper and lower levels, the degree of protection selectivity conflict between the protection device and adjacent protection devices is determined; Based on the breaking capacity margin, the thermal shock margin, and the degree of protection selectivity conflict, the breaking risk index corresponding to the protection device is determined.

[0010] Preferably, the step of generating protection action parameters and linkage control strategies based on the fault risk index, the selectivity relationship between upper and lower level protection, and the load importance data includes: The total system failure risk is determined based on the failure risk weight of the candidate failure point, whether the protection device participates in the protection control of the candidate failure point, and the failure risk index. The estimated power outage loss is determined based on the load set affected by the protection action, the load power, the expected power outage duration, and the load importance coefficient. Based on the time difference between upper and lower level protection actions and the difference in protection coordination levels, determine the selective failure penalty; Determine the cost of adjusting the protection settings based on the parameter differences before and after the protection action parameter adjustment; The fault clearance delay penalty is determined based on the relationship between the predicted fault clearance time and the allowed fault clearance time. Based on the total system failure risk, the estimated power outage loss, the selective failure penalty, the protection setting adjustment cost, and the fault clearing delay penalty, an adaptive protection control optimization model is constructed. Under the constraints of breaking capacity safety, thermal shock, upper and lower level protection selectivity, fault clearing time, setting adjustment stability, and load impact, the protection action parameters and the linkage control strategy are generated.

[0011] Preferably, after performing adaptive protection control on the target low-voltage power distribution system based on the protection action parameters and the linkage control strategy, the method further includes: Collect protection action feedback data, which includes at least one of the following: actual fault current peak value, actual fault current duration, actual protection device operation time, contact temperature rise change, arc duration, disconnection success status, failure to operate status, over-level trip status, and power outage range. Based on the actual fault current peak value and the actual fault current duration, determine the actual thermal shock energy that the protection device withstands during this protection operation; Based on the actual thermal shock energy, the temperature rise change of the contact, the duration of the arc, the actual action time of the protection device, and the successful disconnection status, the degree of state deterioration of the protection device after this protection action is determined. Based on the aforementioned state deterioration amount, the health state correction coefficient corresponding to the protection device is updated; The actual effective breaking capacity of the protection device is updated based on the updated health status correction coefficient, and the breaking capacity margin and breaking risk index are updated based on the updated actual effective breaking capacity.

[0012] Secondly, the present invention also provides a high breaking capacity adaptive protection control device for low-voltage power distribution systems, the device comprising: The data acquisition module is used to acquire multi-source status data of the target low-voltage power distribution system. The multi-source status data includes topology operation data, protection device parameters, circuit breaker health status data, environmental status data, and load importance data. The fault current determination module is used to construct a dynamic equivalent impedance network of the target low-voltage power distribution system based on the topology operation data, and determine the expected fault current of the preset candidate fault point under the current operation mode according to the dynamic equivalent impedance network. The breaking capacity determination module is used to dynamically correct the rated breaking capacity of the protection device based on the protection device parameters, the circuit breaker health status data and the environmental status data, so as to obtain the actual effective breaking capacity of the protection device under the current operating state. The breaking risk determination module is used to determine the breaking capacity margin of the protection device for the candidate fault point based on the expected fault current and the actual effective breaking capacity, and to determine the breaking risk index corresponding to the protection device by combining the fault thermal shock energy corresponding to the candidate fault point and the selectivity relationship between the upper and lower level protections. The linkage control determination module is used to generate protection action parameters and linkage control strategies based on the tripping risk index, the selectivity relationship between upper and lower level protections, and the load importance data. The linkage control strategy is used to maintain the lower level protection with priority when the tripping capacity margin of the protection device meets the preset safe tripping conditions, and to execute at least one of the following when the tripping capacity margin of the protection device does not meet the safe tripping conditions: upper level backup protection, current limiting control, distributed power supply current limiting, interruptible load shedding, and topology adjustment. The protection control execution module is used to perform adaptive protection control on the target low-voltage power distribution system based on the protection action parameters and the linkage control strategy.

[0013] Thirdly, the present invention also provides an electronic device, the electronic device including a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the method as described in the first aspect.

[0014] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, the computer-readable storage medium storing computer-executable instructions for performing the method as described in the first aspect.

[0015] The beneficial effects of this invention are: This invention acquires topology operation data, protection device parameters, circuit breaker health status data, environmental status data, and load importance data of the target low-voltage power distribution system. First, it constructs a dynamic equivalent impedance network based on the current operating mode and determines the expected fault current of candidate fault points. Then, it combines the rated breaking capacity of the protection device, the actual health degradation state, and the operating environment to obtain the current actual effective breaking capacity. Subsequently, it determines the breaking capacity margin based on the matching relationship between the expected fault current and the actual effective breaking capacity, and combines the fault thermal shock energy and the selectivity relationship between upper and lower level protections to form a breaking risk index. Finally, it generates protection action parameters and linkage control strategies. Therefore, this application can avoid the problem of distorted breaking capacity judgment caused by protection control based solely on fixed protection settings or nameplate breaking capacity. It enables the system to identify the actual breaking capacity reduction of circuit breakers caused by contact wear, increased breaking frequency, increased temperature rise, or environmental deterioration. At the same time, when the lower-level protection device has a safe breaking margin, it maintains the priority operation of the lower-level protection to reduce the power outage range and maintain protection selectivity. When the breaking capacity of the lower-level protection device is insufficient, it reduces the fault current or transfers the breaking task through methods such as upper-level backup protection, current limiting control, distributed power supply current limiting, interruptible load disconnection, or topology adjustment. This improves the fault clearing reliability of the low-voltage power distribution system under high short-circuit current levels and changing operating conditions, and reduces the risk of breaking failure, thermal shock damage, and cascading tripping. Attached Figure Description

[0016] Figure 1 A flowchart of a high breaking capacity adaptive protection control method for low-voltage power distribution systems; Figure 2 This is a schematic diagram of a high breaking capacity adaptive protection and control device for low-voltage power distribution systems. Figure 3 This is a schematic diagram of the structure of an electronic device. Detailed Implementation

[0017] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0019] In this application, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0020] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. Furthermore, in the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if there is transmission of electrical signals or data between the connected objects.

[0021] In this embodiment, the target low-voltage power distribution system can be a low-voltage distribution room, a prefabricated substation, a low-voltage busbar system in an industrial park, a low-voltage power distribution system in a public building, a low-voltage power distribution system with centralized access to charging piles, or a low-voltage power distribution system containing distributed power sources and energy storage. A low-voltage power distribution system typically includes incoming-side protection devices, feeder-side protection devices, branch circuit protection devices, bus tie switches, tie switches, interruptible load switches, and distributed power source or energy storage access points. Because low-voltage power distribution systems have a large number of branches, multiple protection levels, and frequent load changes, the source, magnitude, and duration of the fault current at a candidate fault point may change when the system operation mode changes. If fixed protection settings and nameplate breaking capacity are still used for protection control, it is easy to encounter the problem that the actual breaking capacity of the lower-level protection device is insufficient but it is still forced to break, leading to failure to operate, breaking failure, contact erosion expansion, or upper-level over-tripping.

[0022] like Figure 1 As shown, this invention provides a high-breaking-capacity adaptive protection control method for low-voltage power distribution systems, the method comprising: 101. Obtain multi-source status data of the target low-voltage power distribution system. The multi-source status data includes topology operation data, protection device parameters, circuit breaker health status data, environmental status data, and load importance data.

[0023] Multi-source state data provides the foundation for subsequent construction of dynamic equivalent impedance networks, calculation of expected fault currents, correction of actual effective breaking capacity, determination of breaking risk indicators, and generation of linkage control strategies. Topology operation data reflects the current electrical connection status of the target low-voltage power distribution system, including the connection relationships between low-voltage buses, feeder branches, bus tie switches, tie switches, protection devices, load nodes, and controllable power supply access points, as well as the open / closed status of each switch. Through topology operation data, it is possible to determine which power paths supply candidate fault points under the current operating mode, which branches the fault current will pass through, and which protection devices are on the fault current propagation path.

[0024] Protection device parameters characterize the rated capacity and protective operating characteristics of the protection device, including rated current, rated ultimate short-circuit breaking capacity, rated operational short-circuit breaking capacity, instantaneous protection threshold, short-delay protection threshold, long-delay protection curve, operating delay, and protection coordination level. The rated ultimate short-circuit breaking capacity can be understood as the maximum short-circuit current that the protection device can break under specified conditions, while the rated operational short-circuit breaking capacity can be understood as the short-circuit breaking capacity that the protection device can maintain a certain operational capability after breaking the short circuit. Together, they reflect the basic breaking capacity of the protection device.

[0025] Circuit breaker health status data reflects whether the current actual condition of the protection device has deviated from its factory or rated condition. This includes contact wear, number of short-circuit breaks, cumulative number of trips, contact resistance, terminal temperature rise, operating mechanism operating time, and arc-extinguishing chamber deterioration. This data is not used solely for maintenance diagnostics, but rather to correct the rated breaking capacity of the protection device, making the subsequent actual effective breaking capacity closer to real-world conditions. For example, after a circuit breaker has undergone multiple short-circuit breaks, its contact surface may have been eroded, contact resistance increased, and terminal temperature rise increased. Even if the nameplate breaking capacity remains unchanged, its actual safe breaking capacity should be reduced.

[0026] Environmental condition data is used to reflect the environmental impact inside the distribution cabinet or box where the protection device is located, including cabinet temperature, humidity, dust pollution level, and heat dissipation status. High temperature environments reduce the circuit breaker's ability to withstand thermal shock, humidity and dust may affect insulation and arc extinguishing environment, and poor heat dissipation will exacerbate the temperature rise of contacts and terminals. Therefore, this embodiment incorporates environmental condition data into the actual effective breaking capacity correction process.

[0027] Load importance data is used to measure the power outage impact corresponding to different protection action ranges, including load power, load level, interruptibility attribute, power outage loss coefficient, and recovery priority. Load importance data is used to generate subsequent linkage control strategies. When it is necessary to execute upper-level backup protection, interruptible load disconnection, or topology adjustment, priority can be given to avoiding power outage impact on important loads, and priority can be given to control objects that contribute significantly to fault current reduction and have a smaller power outage impact.

[0028] For example, in a low-voltage power distribution system containing a low-voltage busbar, three feeders, a bus tie switch, a distributed photovoltaic (PV) connection point, and multiple charging pile loads, the system can periodically collect data on busbar voltage, feeder current, bus tie switch status, feeder circuit breaker health status, cabinet temperature, and the interruptibility attributes of the charging pile loads. When the bus tie switch is closed and the distributed PV is grid-connected, the fault current at a candidate fault point at the end of a feeder may be contributed by both the incoming power supply and the distributed PV, requiring these factors to be included in the expected fault current calculation in subsequent steps.

[0029] 102. Construct a dynamic equivalent impedance network of the target low-voltage power distribution system based on topology operation data, and determine the expected fault current of the preset candidate fault point under the current operation mode based on the dynamic equivalent impedance network.

[0030] A dynamic equivalent impedance network (EMB) is a network model generated in real time based on current topology operation data to characterize the fault current propagation path and equivalent impedance relationship of a target low-voltage power distribution system. Unlike a fixed topology model, the EMB can be updated according to the open / closed status of incoming switches, feeder switches, bus tie switches, tie switches, controllable power supply access points, and load-side switches. If the bus tie switch is closed, an electrical connection is formed between the two bus segments, and the candidate fault point may be powered by multiple power supply paths; if the tie switch is open, the corresponding tie branch no longer participates in fault current propagation; if the distributed power supply is in grid-connected state, the distributed power supply may contribute fault current to the candidate fault point.

[0031] The selection of candidate fault points is pre-set and usually covers typical short-circuit fault locations such as the protection device outlet, branch end, and bus side, ensuring that all fault scenarios requiring the protection device to operate are covered.

[0032] 103. Based on the protection device parameters, circuit breaker health status data, and environmental status data, the rated breaking capacity of the protection device is dynamically corrected to obtain the actual effective breaking capacity of the protection device under the current operating state.

[0033] Rated breaking capacity can include rated ultimate short-circuit breaking capacity and rated operational short-circuit breaking capacity. Rated ultimate short-circuit breaking capacity indicates the maximum short-circuit current that the protection device can break under specified conditions, while rated operational short-circuit breaking capacity indicates the breaking capacity of the protection device to continue meeting certain operational requirements after a short-circuit break. In actual low-voltage power distribution systems, directly using rated ultimate short-circuit breaking capacity as the basis for protection control may overestimate the circuit breaker's breaking capacity after long-term operation; conversely, using only rated operational short-circuit breaking capacity may be overly conservative in certain backup protection scenarios. Therefore, it is necessary to dynamically adjust the rated breaking capacity of the protection device by combining protection device parameters, circuit breaker health status data, and environmental condition data to obtain a more accurate and effective breaking capacity that better reflects the actual operating conditions on site.

[0034] 104. Based on the expected fault current and the actual effective breaking capacity, determine the breaking capacity margin of the protection device for the candidate fault point, and combine the fault thermal shock energy corresponding to the candidate fault point and the selectivity relationship between the upper and lower level protections to determine the breaking risk index corresponding to the protection device.

[0035] Among these parameters, a larger breaking capacity margin indicates that the protection device has more redundant capacity to handle fault interruption, while a smaller margin, or even a negative margin, indicates that the actual breaking capacity is insufficient to safely interrupt the current fault. Fault thermal shock energy reflects the level of thermal stress that the protection device needs to withstand during the interruption process after a fault occurs. Higher thermal shock energy places higher demands on the breaking capacity of the protection device, further increasing the interruption risk. The selectivity relationship between upper and lower level protection devices clarifies the action priority and action delay coordination between the current protection device and upper and lower level protection devices. It is used to determine whether the current protection device needs to act first in the current fault scenario, and how to coordinate the actions of upper and lower level protection devices if the current protection device does not have sufficient breaking capacity, avoiding cascading tripping or interruption failure.

[0036] 105. Based on the tripping risk index, the selectivity relationship between upper and lower level protections, and the load importance data, generate protection action parameters and linkage control strategies. The linkage control strategies are used to maintain the lower level protections in priority when the tripping capacity margin of the protection device meets the preset safe tripping conditions, and to execute at least one of the following when the tripping capacity margin of the protection device does not meet the safe tripping conditions: upper level backup protection, current limiting control, distributed power supply current limiting, interruptible load shedding, and topology adjustment.

[0037] The protection action parameters may include the instantaneous protection threshold, short-delay protection threshold, short-delay action time, backup protection activation conditions, and action priority of the target protection device. The linkage control strategy refers to coordinated control actions generated to reduce fault current, reduce breaking risk, or minimize the impact of power outages when the breaking capacity margin of the protection device is insufficient or the thermal shock risk is high. These actions include upper-level backup protection, current limiting control, distributed power source current limiting, energy storage withdrawal from fault current support, interruptible load shedding, bus tie switch tripping, and tie switch disconnection.

[0038] 106. Based on protection action parameters and linkage control strategies, perform adaptive protection control on the target low-voltage power distribution system.

[0039] In this context, adaptive protection control refers to converting protection action parameters and linkage control strategies into control actions for protection devices, controllable power supplies, controllable switches, and load-side execution objects. Specifically, the action threshold, action delay, and backup protection activation conditions of the target protection device can be determined based on the protection action parameters; the execution objects participating in the control can be determined based on the linkage control strategy, and these execution objects may include at least one of the following: lower-level protection devices, upper-level protection devices, current limiting devices, distributed power supplies, energy storage, interruptible load switches, bus tie switches, and tie switches.

[0040] When the linkage control strategy prioritizes the action of the lower-level protection device, it controls the lower-level protection device to perform fault clearing according to the corresponding action threshold and action delay, while simultaneously controlling the upper-level protection device to maintain a backup state according to the backup protection activation conditions. This method is suitable for scenarios where the breaking capacity margin and thermal shock margin of the lower-level protection device both meet safety requirements, and can reduce the power outage range while ensuring fault clearing.

[0041] When the linkage control strategy corresponds to high breaking capacity coordinated control, the controlled execution object performs at least one of the following: upper-level backup protection, current limiting, distributed power source current limiting, energy storage withdrawal from fault current support, interruptible load shedding, bus tie switch tripping, or tie switch disconnection, in order to reduce the expected fault current at the candidate fault point or reduce the power outage impact caused by protection actions. For example, if the dynamic equivalent impedance network shows that the bus tie switch closure causes a significant increase in the fault current at the candidate fault point, the bus tie switch can be tripped first to reduce the parallel power supply path; if the distributed power source fault current contribution is high, the distributed power source can be controlled to enter current limiting mode; if the lower-level protection device has insufficient breaking capacity but the upper-level protection device has sufficient margin, the upper-level protection device can be controlled as the high breaking capacity execution end.

[0042] After executing the corresponding control action, the action execution status and electrical operation status can be obtained and used as protection action feedback data. The action execution status can include whether the protection device operated successfully, whether the switch was successfully tripped, whether the controllable power supply completed current limiting, and whether the interruptible load was successfully disconnected. The electrical operation status can include whether the fault current decreased, whether the bus voltage recovered, whether the feeder current dropped, and whether the power outage range met expectations. The above feedback data is used to judge the effectiveness of this protection control and can also be used for subsequent health status correction coefficients and action time prediction model updates.

[0043] This application obtains topology operation data, protection device parameters, circuit breaker health status data, environmental status data, and load importance data of the target low-voltage power distribution system. First, it constructs a dynamic equivalent impedance network based on the current operating mode and determines the expected fault current of candidate fault points. Then, it combines the rated breaking capacity of the protection device, the actual health degradation state, and the operating environment to obtain the current actual effective breaking capacity. Subsequently, it determines the breaking capacity margin based on the matching relationship between the expected fault current and the actual effective breaking capacity, and combines the fault thermal shock energy and the selectivity relationship between upper and lower level protections to form a breaking risk index. Finally, it generates protection action parameters and linkage control strategies. Therefore, this application can avoid the problem of distorted breaking capacity judgment caused by protection control based solely on fixed protection settings or nameplate breaking capacity. It enables the system to identify the actual breaking capacity reduction of circuit breakers caused by contact wear, increased breaking frequency, increased temperature rise, or environmental deterioration. At the same time, when the lower-level protection device has a safe breaking margin, it maintains the priority operation of the lower-level protection to reduce the power outage range and maintain protection selectivity. When the breaking capacity of the lower-level protection device is insufficient, it reduces the fault current or transfers the breaking task through methods such as upper-level backup protection, current limiting control, distributed power supply current limiting, interruptible load disconnection, or topology adjustment. This improves the fault clearing reliability of the low-voltage power distribution system under high short-circuit current levels and changing operating conditions, and reduces the risk of breaking failure, thermal shock damage, and cascading tripping.

[0044] Furthermore, a dynamic equivalent impedance network for the target low-voltage distribution system is constructed based on topology operation data. Based on this network, the expected fault current at preset candidate fault points under the current operating mode is determined. This includes: determining the connection relationships and conduction states between low-voltage buses, feeder branches, protection devices, load nodes, bus tie switches, tie switches, and controllable power supply access points in the target low-voltage distribution system based on topology operation data; constructing a dynamic equivalent impedance network to characterize the fault current propagation path under the current operating mode based on the connection relationships and conduction states; and within the dynamic equivalent impedance network... The process involves determining the set of conducting branches between the power supply equivalent point and the candidate fault point, and then determining the equivalent impedance of the candidate fault point based on the branch impedance in the set of conducting branches, the power supply equivalent impedance, and the local connection impedance corresponding to the candidate fault point. Based on the equivalent impedance, operating voltage, and fault transition impedance of the candidate fault point, the basic fault current of the candidate fault point under the current operating mode is determined. Finally, based on the controllable power supply access status that is electrically connected to the candidate fault point in the dynamic equivalent impedance network, the basic fault current is corrected to obtain the expected fault current of the candidate fault point under the current operating mode.

[0045] Furthermore, based on the access status of controllable power sources that are electrically connected to the candidate fault point in the dynamic equivalent impedance network, the basic fault current is corrected to obtain the expected fault current of the candidate fault point under the current operating mode. This includes: identifying controllable power sources that are electrically connected to the candidate fault point in the dynamic equivalent impedance network, where the controllable power sources include at least one of distributed power sources and energy storage; determining the contribution of the controllable power source to the fault current of the candidate fault point based on the electrical distance between the controllable power source and the candidate fault point; and determining the expected fault current of the candidate fault point under the current operating mode based on the basic fault current and the contribution of the fault current.

[0046] The connection relationship characterizes whether there is a physical or electrical connection between electrical components in the target low-voltage power distribution system, while the conduction state characterizes whether the connection actually participates in power supply or fault current propagation under the current operating mode. For example, although the bus tie switch structurally connects two low-voltage busbars, it only forms a conduction state when the bus tie switch is closed; although the tie switch connects different feeders, it can only form a fault current bypass when it is closed; although the distributed power supply access point exists in the topology, it only contributes fault current to the candidate fault point when it is connected to the grid and has not withdrawn from fault current support.

[0047] When constructing a dynamic equivalent impedance network based on connection relationships and conduction states, the following process can be followed: First, low-voltage busbars, feeder nodes, load nodes, and distributed power supply access points are designated as nodes; second, cables, busbars, tie lines, and switch connection sections are designated as branches; third, each branch is assigned a current impedance parameter; finally, non-conducting branches are deleted or their conduction weight is reduced according to the switch's open / closed state, thereby obtaining the dynamic equivalent impedance network under the current operating mode.

[0048] This dynamic equivalent impedance network is used to determine the propagation path of fault current. For any candidate fault point, starting from the power supply equivalent point, a conduction path to the candidate fault point is searched in the network. The branch impedance, power supply equivalent impedance, and local connection impedance in the conduction path are accumulated to obtain the equivalent impedance corresponding to the candidate fault point. The local connection impedance here reflects the influence of the location of joints, contacts, busbar connection points, etc., on the fault current calculation, which can improve the accuracy of the expected fault current calculation.

[0049] Through the above process, the basic fault current at the candidate fault point is directly related to the current topology operating state. If the bus tie switch is closed, the power supply path increases, and the basic fault current may increase; if the tie switch is open, the fault current path decreases, and the basic fault current may decrease. This result is then used to correct the contribution of subsequent controllable power sources, thereby forming the expected fault current.

[0050] In practical implementation, the target low-voltage power distribution system can be abstracted as a graph structure: ; in, express The dynamic equivalent impedance network at any given time. Represents a set of nodes. Represents the set of branches. Indicates a collection of protective devices. Represents the load set. This represents a collection of controllable power sources or energy storage. (Node set) This can include low-voltage busbar nodes, feeder nodes, branch box nodes, load nodes, distributed power supply access nodes, and grounding reference nodes; branch sets. This may include cables, busbars, tie lines, internal connecting conductors of switches, and local connection points; a collection of protection devices. It can include incoming line protection, feeder protection, branch protection and load-side protection.

[0051] For branch roads Its current impedance can be obtained by correcting for branch resistance, branch reactance, and temperature: ; in, Indicates a branch exist Impedance at time, Indicates reference temperature The branch resistance below, Indicates the temperature coefficient of resistance of a conductor. Indicates a branch Current temperature, Indicates branch reactance, This represents the imaginary unit. This formula illustrates that branch impedance is not constant but can be adjusted according to changes in operating temperature.

[0052] In identifying candidate failure points Then, the source equivalent point to the candidate fault point can be determined in the dynamic equivalent impedance network. The set of conducting branches And calculate the equivalent impedance corresponding to the candidate fault point: ; in, Indicates candidate fault points exist The equivalent impedance at time t, Indicates the equivalent impedance on the power supply side. This shows the path from the power equivalent point to the candidate fault point. The set of conducting branches, Indicates the branch in the set of conducting branches impedance, This represents the local connection impedance corresponding to the candidate fault point. Local connection impedance can include terminal connection impedance, busbar connector impedance, switch contact impedance, etc. Incorporating local connection impedance into the calculation makes the subsequent expected fault current more closely match the actual operating conditions.

[0053] For a three-phase short-circuit fault, the candidate fault point The basic fault current can be determined as follows: ; in, Indicates candidate fault points exist The three-phase short-circuit fault current at any given moment. This represents the line voltage at the location of the candidate fault point. This represents the fault transition impedance. For single-phase ground faults, it can be calculated based on sequence impedance: ; in, Indicates candidate fault points Single-phase ground fault current, Represents phase voltage , , These represent the positive-sequence, negative-sequence, and zero-sequence equivalent impedances, respectively. For two-phase short-circuit or two-phase-to-ground faults, the corresponding fault current can be determined based on the sequence component relationship between the phase-to-phase faults. In practical applications, the larger value among the basic fault currents under different fault types can be taken as a conservative calculation result.

[0054] When there are distributed power sources or energy storage systems connected to candidate fault points in the dynamic equivalent impedance network, their fault current contribution also needs to be added to the base fault current. A controllable power supply for candidate fault points The contribution of fault current can be expressed as: ; in, Indicates the first A controllable power supply for candidate fault points The contribution of fault current. This indicates the status of the controllable power supply being connected. Indicates the fault current multiple or current limiting multiple. Indicates the rated current of the controllable power supply. This represents the electrical distance influence coefficient between the controllable power supply and the candidate fault point. If the controllable power supply is not connected or has been removed from fault current support, then... A lower value or 0 can be selected; if the controllable power supply is in current-limiting control mode, then The corresponding reduction.

[0055] Therefore, candidate fault points The expected fault current can be expressed as: ; in, Indicates candidate fault points The expected fault current, Indicates the basic fault current. This indicates the number of controllable power sources that are electrically connected to the candidate fault point. Indicates the first Fault contribution correction factor for each controllable power supply.

[0056] In this process, the expected fault current is no longer a static estimate based on a fixed short-circuit capacity, but is dynamically updated according to changes in topology, switch status, branch impedance, and controllable power supply connection status. The subsequent breaking capacity margin is determined based on the relationship between this expected fault current and the actual effective breaking capacity. Therefore, this step directly affects whether the protection control maintains lower-level priority operation or enters high-breaking-capacity coordinated control.

[0057] Furthermore, based on the protection device parameters, circuit breaker health status data, and environmental status data, the rated breaking capacity of the protection device is dynamically corrected to obtain the actual effective breaking capacity of the protection device under the current operating condition. This includes: determining the rated ultimate short-circuit breaking capacity and rated operating short-circuit breaking capacity of the protection device according to the protection device parameters, and determining the basic breaking capacity of the protection device based on the rated ultimate short-circuit breaking capacity and rated operating short-circuit breaking capacity; determining the health status correction coefficient of the protection device caused by at least one of contact wear, short-circuit breaking frequency, contact resistance, terminal temperature rise, and operating mechanism operation status according to the circuit breaker health status data; determining the environmental correction coefficient of the protection device caused by at least one of cabinet temperature, humidity, dust pollution level, and heat dissipation status according to the environmental status data; and dynamically correcting the rated breaking capacity of the protection device based on the basic breaking capacity, health status correction coefficient, and environmental correction coefficient to obtain the actual effective breaking capacity of the protection device under the current operating condition.

[0058] In practical low-voltage power distribution systems, directly using the rated ultimate short-circuit breaking capacity as the basis for protection and control may overestimate the circuit breaker's breaking capacity after long-term operation; conversely, using only the rated operating short-circuit breaking capacity may be overly conservative in certain backup protection scenarios. Therefore, this embodiment first weights the two to form the basic breaking capacity: ; in, Indicates the first The basic breaking capacity of each protection device Indicates the rated ultimate short-circuit breaking capacity. Indicates the rated short-circuit breaking capacity. and These represent the corresponding weights, and If the system emphasizes continued operational reliability after the breakdown, then it can be improved. If the system is in an emergency backup disconnection scenario, the power consumption can be appropriately increased. .

[0059] Based on the basic breaking capacity, a health status correction factor is determined according to the circuit breaker's health status data. The health status correction factor characterizes the degree to which the actual breaking capacity of the protection device decreases due to operational deterioration. The comprehensive health deterioration index can be determined first. ; in, Indicates the first Each protective device A comprehensive index of health deterioration over time. This represents the normalized value of contact wear. This indicates the cumulative number of short-circuit interruptions. Indicates the number of short-circuit breaks allowed. Indicates the temperature rise of the contacts or terminals. This indicates the upper limit of the allowable temperature rise. Indicates contact resistance. Indicates the upper limit of the allowable contact resistance. Indicates the timing of the operating mechanism's action. This indicates the maximum allowed action time. to This indicates the corresponding influence weight.

[0060] Based on the comprehensive health deterioration index, the health status correction coefficient can be determined: ; in, Indicates the first Each protective device A health status correction factor at any given time. The better the health status, the better. The smaller, The closer to 1, the worse the health condition. The larger, The smaller the value, the better. In this way, data such as contact wear, number of breaks, temperature rise, contact resistance, and operating time are no longer isolated condition detection results, but are directly incorporated into the calculation of the actual effective breaking capacity of the protection device.

[0061] Furthermore, environmental correction factors are determined based on environmental status data: ; in, Represents the environmental correction factor. Indicates the temperature inside the cabinet. Indicates reference temperature. Indicates the humidity influencing factor. Indicates dust pollution factors, Indicates factors affecting poor heat dissipation. to This indicates the weight of environmental impact. When the temperature inside the cabinet is high, the humidity is high, dust pollution is severe, or heat dissipation is poor... reduce.

[0062] Finally, the first The actual effective breaking capacity of a protection device under its current operating state can be expressed as: ; in, This indicates the actual effective breaking capacity of the protection device.

[0063] This application converts the nameplate breaking capacity of the protection device into the breaking capacity that can currently be used for protection control. Compared with directly comparing the expected fault current with the rated breaking capacity, this embodiment can identify hidden breaking risks caused by circuit breaker deterioration, environmental degradation, or abnormal operating mechanism, thereby avoiding overestimation of the breaking capacity.

[0064] Furthermore, based on the expected fault current and the actual effective breaking capacity, the breaking capacity margin of the protection device for candidate fault points is determined. Combining the fault thermal shock energy corresponding to the candidate fault point and the selectivity relationship between upper and lower level protection, the breaking risk index corresponding to the protection device is determined, including: determining the breaking capacity margin of the protection device for candidate fault points based on the difference between the actual effective breaking capacity of the protection device in the current operating state and the expected fault current of the candidate fault point; determining the fault thermal shock energy corresponding to the candidate fault point based on the expected fault current of the candidate fault point and the predicted operating time of the protection device for the candidate fault point; determining the ultimate thermal shock withstand capability of the protection device in the current operating state based on the health status correction coefficient and environmental correction coefficient of the protection device, and determining the thermal shock margin based on the fault thermal shock energy and ultimate thermal shock withstand capability; determining the degree of protection selectivity conflict between the protection device and adjacent protection devices based on the selectivity relationship between upper and lower level protection; and determining the breaking risk index corresponding to the protection device based on the breaking capacity margin, thermal shock margin, and degree of protection selectivity conflict.

[0065] The expected fault current at the candidate fault point is obtained. and the actual effective breaking capacity of the protection device Then, the protection device can be calculated. For candidate fault points Breaking capacity margin: ; in, Indicates the breaking capacity margin. like The value is greater than the preset safety margin threshold, indicating that the protection device... For candidate fault points It has sufficient safety margin for separation; if A value close to 0 indicates that while the protection device may have breaking capacity, its safety margin is relatively small; if If the value is less than or equal to 0, it indicates that the expected fault current has reached or exceeded the actual effective breaking capacity, and the protection device should not be solely responsible for the main breaking task.

[0066] To further consider the thermal shock caused by the fault duration to the protection device, this embodiment calculates the fault thermal shock energy by combining the predicted operating time of the protection device: ; in, Indicates protective device For candidate fault points The thermal shock energy of the fault experienced during the predicted action time. This represents the predicted operating time. If the fault current is approximately stable within the operating time, it can be simplified to: ; Even if the expected fault current does not exceed the actual effective breaking capacity, if the protection operation time is too long, it may lead to excessive thermal shock energy, causing contact erosion, busbar overheating, or cable thermal damage. Therefore, this embodiment not only determines whether the current can be broken, but also whether excessive thermal shock will occur during the operation time.

[0067] The ultimate thermal shock withstand capability of the protection device under the current condition can be determined based on the rated thermal shock withstand capability, the health condition correction factor, and the environmental correction factor: ; in, Indicates protective device The ultimate thermal shock resistance under current operating conditions. Indicates the rated thermal shock resistance. Indicates the health status correction factor. This represents the environmental correction factor. From this, the thermal shock margin can be determined: ; in, This indicates the thermal shock margin. A low margin indicates that even if the protection device has a decent current breaking capacity, it may still be at risk of tripping due to excessive thermal shock.

[0068] The selectivity relationship between lower-level and higher-level protection devices reflects the operational coordination between lower-level and higher-level protection devices. For lower-level protection devices... and higher-level protection devices It can calculate the time difference of the action: ; in, This indicates that the upper and lower level protections are targeting candidate fault points. Action time difference, This indicates the predicted activation time of the upstream protection device. This indicates the predicted operating time of the downstream protection device. If If the difference is less than the preset minimum level difference, the upper and lower level protections may operate simultaneously or trip out of order, thus confirming the existence of protection selectivity conflict.

[0069] The degree of selective conflict in protection can be determined based on the difference in action time, the difference in protection coordination level, and the intersection of protection action curves. For example: ; in, Indicates the degree of selective conflict in protection. This indicates the minimum action level difference required between upper and lower level protection. When the actual action time difference is less than the minimum action level difference... Increase.

[0070] Based on the above parameters, the tripping risk index corresponding to the protection device can be determined: ; in, Indicates protective device For candidate fault points Risk indicators for segmentation, This represents the risk mapping function for breaking capacity margin. This represents the thermal shock margin risk mapping function. , , This represents the weighting coefficient. To further illustrate the degradation of arc-extinguishing capability, additional weighting coefficients can be added. ,in This represents the arc-extinguishing capability degradation factor.

[0071] Specifically, the expected fault current, actual effective breaking capacity, fault duration, thermal shock capability, and protection selectivity are unified into a breaking risk index. This ensures that subsequent protection action parameters and linkage control strategies are no longer determined solely by a fixed threshold, but rather by comprehensive risk. This allows selective protection to be maintained when lower-level protection has sufficient margin, and high-breaking-capacity coordinated control to be triggered when lower-level protection lacks sufficient margin.

[0072] Furthermore, based on the disconnection risk index, the selectivity relationship between upper and lower level protection, and load importance data, protection action parameters and linkage control strategies are generated, including: determining the total system disconnection risk based on the fault risk weight of candidate fault points, whether the protection device participates in the protection control of candidate fault points, and the disconnection risk index; determining the estimated power outage loss based on the load set affected by the protection action, load power, expected power outage duration, and load importance coefficient; determining the selective failure penalty based on the time difference between upper and lower level protection actions and the protection coordination level difference; determining the protection setting adjustment cost based on the parameter differences before and after the protection action parameter adjustment; determining the fault clearing delay penalty based on the relationship between the predicted fault clearing time and the allowable fault clearing time; and constructing an adaptive protection control optimization model based on the total system disconnection risk, estimated power outage loss, selective failure penalty, protection setting adjustment cost, and fault clearing delay penalty, and generating protection action parameters and linkage control strategies under the constraints of disconnection capacity safety, thermal shock, upper and lower level protection selectivity, fault clearing time, setting adjustment stability, and load impact.

[0073] In practice, the breaking risk level of the protection device for the candidate fault point can be determined first based on the breaking risk index. For example, when both the breaking capacity margin and the thermal shock margin meet the safety threshold and the degree of selective conflict is low, it can be determined as a low-risk level; when the breaking capacity margin is close to the safety threshold but not lower than the threshold, it can be determined as a critical-risk level; when the breaking capacity margin is lower than the safety threshold or the thermal shock margin is insufficient, it can be determined as a high-risk level.

[0074] Then, action coordination constraints are determined based on the selectivity relationship between upper and lower level protection. If the lower-level protection device has safe disconnection capability, its operation should be prioritized to reduce the power outage range; if the lower-level protection device does not have safe disconnection capability, the selectivity holding weight should be appropriately reduced to allow the upper-level protection device to participate in high-disconnection backup control. In other words, this embodiment does not always mechanically maintain lower-level priority, but maintains selectivity when the disconnection safety conditions are met, and prioritizes safe disconnection when the disconnection safety conditions are not met.

[0075] Furthermore, the impact weight of power outages is determined based on load importance data. For critical loads, such as fire-fighting loads, critical data center loads, critical hospital loads, or important production loads, their load importance coefficients are high, and direct disconnection should be avoided as much as possible when generating linkage control strategies. For interruptible loads, non-critical charging pile loads, and general lighting loads, their load importance coefficients are low, and they can be used as priority candidates in fault current reduction strategies.

[0076] An adaptive protection control optimization model can be constructed, and its comprehensive objective function is: ; in, Indicates candidate linkage control strategies The comprehensive optimization target value; Indicates the total risk of system failure; This indicates the estimated losses due to the power outage; This indicates selective destructive punishment; This indicates the cost of adjusting the protection setting; Indicates a penalty for fault clearance delay; , , , , These represent the weight coefficients of the corresponding cost terms; The total system failure risk can be expressed as: ; in, Represents the set of candidate fault points. Indicates candidate fault points Fault risk weights Indicates a collection of protective devices. Indicates protective device Whether to participate in the candidate fault point Protection and control, This indicates the corresponding risk indicator.

[0077] The estimated power outage loss can be expressed as: ; in, This represents the set of loads affected by the protection action. Indicates the first Each load power, Indicates the expected duration of the power outage. This represents the load importance coefficient. This formula is used to ensure that the strategy generation considers not only whether the fault can be cleared, but also the impact of power outages.

[0078] When the breaking capacity margin of the protection device meets the safe breaking conditions, and the time difference between the upper and lower level protection actions meets the minimum level difference requirement, protection action parameters that maintain the priority action of the lower level protection can be generated. That is, the lower level protection device is controlled to perform fault clearing according to the original or finely adjusted action threshold and action delay, while the upper level protection device remains in standby status.

[0079] When the breaking capacity margin of the protection device does not meet the safe breaking conditions, a linkage control strategy can be selected based on the breaking risk level and the weight of the power outage impact. For example, when the upstream protection device has a sufficient breaking margin, the upstream protection device can be designated as the high breaking capacity execution terminal; when distributed power sources contribute significantly to the fault current of the candidate fault point, distributed power source current limiting can be prioritized; when the bus tie switch closure causes the candidate fault point to be powered by multiple power supply paths, the bus tie switch can be tripped to reduce the fault current; when non-critical interruptible loads have a reducing effect on the fault current, interruptible load disconnection can be implemented.

[0080] To avoid the linkage control strategy becoming an isolated action, this embodiment can determine the fault current reduction priority based on the contribution of fault current reduction and control cost: ; in, Represents controllable objects For candidate fault points Fault current reduction priority, Represents controllable objects The fault current that can be reduced after the action. Represents controllable objects The cost of control, It is a very small positive number. Control costs can include the impact of power outages, action time, execution risks, and recovery difficulty. Preferred selection. Involving larger controllable objects in the linkage control can reduce the impact of unnecessary power outages while reducing fault current.

[0081] Selective failure penalty is used to measure whether the coordination between upstream and downstream protection devices has been disrupted. For candidate fault points... In candidate linkage control strategies Lower-level protection devices The predicted action time is Upper-level protection device The predicted action time is Then the time difference between the upper and lower level protection actions can be expressed as: ; in, Indicates the upper-level protection device With lower-level protection devices For candidate fault points The time difference of the action.

[0082] If the minimum required protection coordination level difference between upper and lower level protection is Then, the selective destruction penalty can be expressed as: ; in, Indicates candidate linkage control strategies Corresponding selective destruction penalties; Indicates candidate fault points Fault risk weights; Indicating in candidate linkage control strategies Lower protection device and higher-level protection devices Whether to participate in the candidate fault point The protection coordination between superiors and subordinates is 1 when participating and 0 when not participating; Indicates the selective weighting coefficient; Indicates protective device With the upper protection device The minimum protection coordination level required between the two.

[0083] in, This means that when the actual action time difference meets the minimum protection coordination level difference, the selective destruction penalty is 0; when the actual action time difference is less than the minimum protection coordination level difference, it indicates that the upper-level protection may act in advance or the upper and lower-level protection may act simultaneously, thus generating a selective destruction penalty.

[0084] According to the protection device The breaking capacity margin and thermal shock margin are dynamically determined. For example, when the next level protection device... When both the breaking capacity margin and the thermal shock margin meet the safety threshold, Take the larger value to emphasize maintaining the priority of lower-level protection; when the lower-level protection device... The breaking capacity margin or thermal shock margin does not meet the safety threshold, and the upstream protection device... When the safety disconnection condition is met, A smaller value can be selected to allow the higher-level protection device to act ahead of time as a high-breaking-capacity actuator.

[0085] The cost of protection setting adjustment is used to measure the magnitude of change in protection action parameters relative to the parameters before adjustment, avoiding frequent adjustments of protection settings due to short-term load fluctuations, minor topology changes, or measurement errors. Let... Indicates protective device The The original values ​​of the protection action parameters before adjustment. Indicating in candidate linkage control strategies The adjusted parameter values ​​generated below, This indicates the maximum allowable adjustment range of the protection action parameters. Therefore, the cost of adjusting the protection settings can be expressed as: ; in, Indicates candidate linkage control strategies The corresponding cost of adjusting the protection settings; Indicates the first Adjustment weights for protection action parameters; Indicates candidate linkage control strategies Next Whether the protection action parameters have been adjusted; set to 1 if adjusted, and 0 if not adjusted.

[0086] Protective action parameter types This can include at least one of the following: instantaneous protection threshold, short-delay protection threshold, short-delay action time, long-delay protection curve parameters, backup protection activation conditions, and action priority parameters. For example, it can be... Indicated as a protective device The instantaneous protection threshold will This is represented as the short-delay protection threshold. Represented as short delay action time, This indicates the backup protection activation time.

[0087] To further enhance the suppression of sharp adjustments, a squared form can also be used: ; The larger the adjustment range of the protection action parameters, the faster the cost of adjusting the protection settings increases, thereby suppressing unnecessary large changes in settings.

[0088] The fault clearing delay penalty is used to measure whether candidate linkage control strategies will cause the fault clearing time to exceed the allowable range, avoiding excessive delays in fault clearing to maintain selectivity or reduce the impact of power outages. Let... Indicating in candidate linkage control strategies Next candidate fault point Predicted fault clearing time, Indicates candidate fault points Given the corresponding allowable fault clearing time, the fault clearing delay penalty can be expressed as: ; in, Indicates candidate linkage control strategies Corresponding fault clearance delay penalty; Indicates candidate fault points Fault risk weights; Indicates the predicted fault clearing time; Indicates the allowed fault clearing time.

[0089] If candidate linkage control strategy Including pre-emptive linkage control actions such as distributed power source current limiting, energy storage withdrawal from fault current support, bus tie switch tripping, tie switch disconnection, or interruptible load shedding, the predicted fault clearing time can be further expressed as: ; in, Indicates candidate linkage control strategies The time required for the preceding linkage control action. This indicates the protective device that ultimately undertakes the fault disconnection action. For candidate fault points Predicted action time; protective device It can be a lower-level protection device. It can also be an upstream protection device identified as the high-breaking-capacity execution end under high-breaking-capacity coordinated control. .

[0090] in, It can be represented as: ; Or it can be expressed as: ; in, Indicates candidate linkage control strategies The selected set of controllable objects. Represents controllable objects For candidate fault points The response time required to perform current limiting, fault current support disconnection, tripping, disconnection, or load shedding actions. When multiple linkage actions are executed in parallel, the maximum response time can be used; when multiple linkage actions need to be executed sequentially, the sum of the response times can be used.

[0091] like Less than or equal to Then the fault clearing delay penalty is 0; if Greater than If the fault is cleared too slowly, it may lead to an increase in the thermal shock energy of the fault or an expansion of the fault's impact, thus incurring a delay penalty.

[0092] Breaking capacity safety constraints are used to ensure that the protection device selected as the main protection action target or high breaking capacity execution target has sufficient breaking capacity margin when performing protection breaking actions. Let... Indicating in candidate linkage control strategies Under the influence of the action, candidate fault points The corresponding expected fault current; Indicates protective device The actual effective breaking capacity under the current operating state; Indicates protective device For candidate fault points The margin of breaking capacity; Let represent the preset minimum safety margin, then: ; Breaking capacity safety constraints can be expressed as: ; Or equivalently represented as: ; in, It can be determined by the basic fault current and the amount of fault current reduction after linkage control, for example: ; in, Indicates candidate fault points The basic fault current, Indicates the first A distributed power source or energy storage system is a candidate fault point. The contribution of fault current. Indicating in candidate linkage control strategies Next Fault contribution correction factor for each controllable power supply Indicates candidate linkage control strategies Select controllable object Participate in fault current reduction, Represents controllable objects For candidate fault points The amount of fault current reduction.

[0093] Thermal shock constraints are used to ensure that the thermal shock energy of a fault that a protective device experiences during the predicted operating time does not exceed its allowable thermal shock tolerance under its current condition. Let... Indicates protective device For candidate fault points In candidate linkage control strategies The thermal shock energy of the fault that it can withstand. Indicates protective device The ultimate thermal shock resistance under current operating conditions. Indicates thermal shock margin, Let represent the preset minimum thermal shock margin, then: ; When the fault current is approximately stable within the predicted operating time, it can be simplified to: ; in, Indicates candidate linkage control strategies Lower protection device For candidate fault points Predicted action time.

[0094] The ultimate thermal shock resistance can be expressed as: ; in, Indicates protective device Rated thermal shock resistance Indicates protective device Health status correction factor, Indicates protective device Environmental correction factor.

[0095] Thermal shock margin can be expressed as: ; Thermal shock constraint can be expressed as: ; Or equivalently represented as: ; Selective constraints between upper and lower level protection are used to ensure that when the lower level protection device has a safe disconnection capability, the lower level protection is prioritized to operate, thus preventing the upper level protection from operating prematurely and causing the power outage area to expand. Let... Indicates the lower-level protection device For candidate fault points Predicted action time Indicates the upper-level protection device For candidate fault points Predicted action time This indicates the time difference between the actions of the upper and lower protection systems. Let represent the preset minimum protection coordination level difference, then: ; When the linkage control strategy When the lower-level protection takes priority, the selective constraint between the upper and lower-level protection can be expressed as: ; It can also be expressed as the degree of selective conflict: ; Selectivity constraints can be expressed as: ; in, Indicates the degree of selective conflict in protection. This indicates the maximum permissible level of selective conflict. Typically, this is done while maintaining the priority of lower-level protection actions. It can take 0 or a smaller value close to 0.

[0096] Fault clearing time constraints are used to ensure that the fault corresponding to the candidate fault point can be cleared or effectively current-limited within the allowable time, avoiding excessive thermal shock energy or the expansion of fault impact due to slow action. Let... Indicates candidate linkage control strategies Next candidate fault point Total fault clearing time Indicates candidate fault points The corresponding allowable fault clearing time, Let represent the lead-in control time required to execute coordinated control actions such as current limiting, distributed power supply current limiting, interruptible load shedding, or topology adjustment. ; The fault clearing time constraint can be expressed as: ; If candidate linkage control strategy The fault current reduction action must be performed first, followed by the protection disconnection action. This can include the current limiting response time of distributed power sources, the energy storage exit time, the bus tie switch opening time, the tie switch disconnection time, or the interruptible load shedding time.

[0097] Setting adjustment stability constraints are used to limit the adjustment range of protection action parameters, preventing the protection device from frequently changing protection settings due to load fluctuations, minor topology changes, or measurement errors. Let... Indicates candidate linkage control strategies Lower protection device The Each protection action parameter, Indicates the protective device before adjustment. The Each protection action parameter, It can represent instantaneous protection threshold, short-delay protection threshold, short-delay action time, or backup protection activation conditions; Indicates the first The maximum allowable relative adjustment range for each protection action parameter is as follows: ; Alternatively, the adjustment amount of multiple protection action parameters can be uniformly expressed as the protection setting adjustment cost: ; The stability constraint for constant value adjustment can be expressed as: ; in, Indicates the first The adjustment weight of each protection action parameter, This indicates the maximum allowable cost of adjusting the protection setting.

[0098] Load impact constraints are used to limit the impact of power outages caused by interlocking control strategies, preventing the unreasonable expansion of outage areas or the disconnection of critical loads in an effort to reduce disconnection risk. Let... Indicates candidate linkage control strategies The corresponding estimated power outage losses, Indicates load The load power, Indicates candidate linkage control strategies Under load The expected duration of the power outage, Indicates load The load importance coefficient, Indicates candidate linkage control strategies Should the load be increased? If affected by a power outage: ; Load influence constraints can be expressed as: ; in, This indicates the maximum estimated loss due to a power outage.

[0099] For critical loads, critical load protection constraints can also be set: ; in, This represents the set of critical loads. This constraint indicates that critical loads should not be prioritized for disconnection if other feasible coordinated control strategies exist. If the fault has seriously threatened system safety and no other feasible strategies exist, this constraint can be relaxed in higher-level protection strategies, but the corresponding outage impact weight should be increased.

[0100] The mathematical solver selects from the candidate linkage control strategies that satisfy the above constraints. The minimum strategy can obtain protection action parameters and linkage control strategies that match the current expected fault current, actual effective breaking capacity, selectivity relationship between upper and lower level protections, and load importance data.

[0101] In this embodiment, the protection action parameters include at least one of the following: instantaneous tripping threshold, short-delay tripping threshold, short-delay action time, long-delay protection curve parameters, upper-level backup protection activation conditions, and protection action priority.

[0102] Furthermore, after performing adaptive protection control on the target low-voltage power distribution system based on protection action parameters and linkage control strategies, the method further includes: collecting protection action feedback data, which includes at least one of the following: actual fault current peak value, actual fault current duration, actual protection device operation time, contact temperature rise change, arc duration, successful disconnection status, failure to operate status, over-level trip status, and power outage range; determining the actual thermal shock energy borne by the protection device in this protection action based on the actual fault current peak value and actual fault current duration; determining the state degradation of the protection device after this protection action based on the actual thermal shock energy, contact temperature rise change, arc duration, actual protection device operation time, and successful disconnection status; updating the health status correction coefficient corresponding to the protection device based on the state degradation; updating the actual effective breaking capacity of the protection device based on the updated health status correction coefficient; and updating the breaking capacity margin and breaking risk indicators based on the updated actual effective breaking capacity.

[0103] The protection action feedback data is used to reflect the actual execution effect of this adaptive protection control. Specifically, the protection action feedback data may include at least one of the following: actual fault current peak value, actual fault current duration, actual protection device operating time, contact temperature rise change, arc duration, successful disconnection status, failure to operate status, cascading trip status, and power outage range. Among them, the actual fault current peak value is used to characterize the maximum current surge that the protection device withstands during this fault; the actual fault current duration is used to characterize the time from the occurrence of the fault current to its disconnection or reduction to a safe level; the actual protection device operating time is used to reflect whether the protection device operates in a timely manner according to the protection action parameters; the contact temperature rise change is used to reflect the thermal effects on the contacts and connection parts during the fault disconnection process; the arc duration is used to reflect whether the arc extinguishing process is normal; the successful disconnection status, failure to operate status, and cascading trip status are used to evaluate whether this protection action has achieved the expected control effect; and the power outage range is used to evaluate the impact of this protection action or linkage control strategy on the load power supply range.

[0104] After obtaining the actual peak fault current and the actual fault current duration, the actual thermal shock energy experienced by the protection device during this protection operation can be determined. Specifically, if the protection device... The actual fault current during this protection action is recorded as follows: The actual fault current duration is denoted as Then the protection device The actual thermal shock energy absorbed during this protective action It can be represented as: ; When the actual fault current change is not significant or only the peak value of the fault current can be collected, an approximate calculation method can be used: ; in, Indicates protective device The actual thermal shock energy absorbed during this protective action Indicates protective device The actual peak fault current collected during this protection operation. This represents the actual duration of the fault current. Through this calculation, the amplitude and duration of the fault current can be uniformly converted into a thermal shock evaluation quantity, which reflects the comprehensive thermal impact of this tripping action on the contacts, arc-extinguishing chamber, terminals, and conductive circuits of the protection device.

[0105] Furthermore, based on the actual thermal shock energy, contact temperature rise change, arc duration, actual operating time of the protection device, and successful disconnection status, the degree of condition degradation of the protection device after this protection operation can be determined. The degree of condition degradation characterizes the extent to which the health status of the protection device deteriorates due to this protection operation. For example, the protection device... Deterioration It can be represented as: ; in, Indicates protective device The degree of condition deterioration after this protective action; Indicates protective device The ultimate thermal shock resistance under current operating conditions; This indicates the change in temperature of the contacts or terminals before and after the current protection action; This indicates the upper limit of the allowable temperature rise variation; Indicates the duration of the arc; Indicates the maximum allowed arc duration; Indicates the actual operating time of the protection device; This indicates the corresponding action delay or action time reference value in the protection action parameters; This represents the abnormal disconnection state factor. When the protection device successfully disconnects and there is no failure to operate or over-level tripping, it takes a smaller value or 0. When there is a disconnection failure, failure to operate, or abnormal over-level tripping, it takes a larger value. , , , , These represent the weighting coefficients of the degradation factors for each state.

[0106] Install protective devices The health status correction factor before the update was: The updated health status correction factor is Then it can be expressed as: ; in, This represents the health status update coefficient. If the actual thermal shock energy experienced by this protection action is large, the contact temperature rise is large, the arc duration is long, or there are situations such as failure to operate or abnormal disconnection, then the degree of health status deterioration is [not specified]. Increase, and thus make Compared to If the current surge of the protection action is small, the action time is normal, and the disconnection is successful, the degree of condition deterioration is small, and the health status correction coefficient is updated only slightly.

[0107] After updating the health status correction coefficient, the actual effective breaking capacity of the protection device in subsequent adaptive protection control can be updated based on the updated health status correction coefficient. Specifically, if the protection device... The basic breaking ability is The environmental correction factor is The updated actual effective segmentation capability It can be represented as: ; in, Indicates protective device Updated actual effective segmentation capability.

[0108] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0109] Based on the same inventive concept, this application also provides a high breaking capacity adaptive protection control device for low-voltage power distribution systems for implementing the high breaking capacity adaptive protection control method for low-voltage power distribution systems described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more cloud-based high breaking capacity adaptive protection control device embodiments for low-voltage power distribution systems provided below can be found in the limitations of the high breaking capacity adaptive protection control method for low-voltage power distribution systems described above, and will not be repeated here.

[0110] like Figure 2 As shown, this application also provides a high breaking capacity adaptive protection control device for low-voltage power distribution systems, the device comprising: The data acquisition module 110 is used to acquire multi-source status data of the target low-voltage power distribution system. The multi-source status data includes topology operation data, protection device parameters, circuit breaker health status data, environmental status data, and load importance data. The fault current determination module 120 is used to construct a dynamic equivalent impedance network of the target low-voltage power distribution system based on topology operation data, and determine the expected fault current of the preset candidate fault point under the current operation mode based on the dynamic equivalent impedance network. Breaking capacity determination module 130 is used to dynamically correct the rated breaking capacity of the protection device based on protection device parameters, circuit breaker health status data and environmental status data, so as to obtain the actual effective breaking capacity of the protection device under the current operating state. The breaking risk determination module 140 is used to determine the breaking capacity margin of the protection device for the candidate fault point based on the expected fault current and the actual effective breaking capacity, and to determine the breaking risk index of the protection device in combination with the fault thermal shock energy corresponding to the candidate fault point and the selectivity relationship between the upper and lower level protection. The linkage control determination module 150 is used to generate protection action parameters and linkage control strategies based on the tripping risk index, the selectivity relationship between upper and lower level protections and the load importance data. The linkage control strategy is used to maintain the lower level protection with priority when the tripping capacity margin of the protection device meets the preset safe tripping conditions, and to execute at least one of the following when the tripping capacity margin of the protection device does not meet the safe tripping conditions: upper level backup protection, current limiting control, distributed power supply current limiting, interruptible load shedding and topology adjustment. The protection control execution module 160 is used to perform adaptive protection control on the target low-voltage power distribution system based on protection action parameters and linkage control strategies.

[0111] like Figure 3As shown, this application also provides an electronic device 10, which includes a memory 20 and a processor 30. The memory 20 stores a computer program, and when the computer program is executed by the processor 30, the processor 30 performs the method as described in the above embodiments.

[0112] The present invention also provides a computer-readable storage medium having a computer program stored thereon, the computer-readable storage medium storing computer-executable instructions for performing the methods as described in the above embodiments.

[0113] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0114] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A high breaking capacity adaptive protection control method for low voltage distribution systems, characterized by: The method includes: Acquire multi-source status data of the target low-voltage power distribution system, including topology operation data, protection device parameters, circuit breaker health status data, environmental status data, and load importance data; Based on the topology operation data, a dynamic equivalent impedance network of the target low-voltage power distribution system is constructed, and based on the dynamic equivalent impedance network, the expected fault current of the preset candidate fault point under the current operation mode is determined. Based on the protection device parameters, the circuit breaker health status data, and the environmental status data, the rated breaking capacity of the protection device is dynamically corrected to obtain the actual effective breaking capacity of the protection device under the current operating state. Based on the expected fault current and the actual effective breaking capacity, the breaking capacity margin of the protection device for the candidate fault point is determined, and combined with the fault thermal shock energy corresponding to the candidate fault point and the selectivity relationship between the upper and lower level protection, the breaking risk index corresponding to the protection device is determined. Based on the tripping risk index, the selectivity relationship between upper and lower level protections, and the load importance data, protection action parameters and linkage control strategies are generated. The linkage control strategy is used to maintain the lower level protection with priority when the tripping capacity margin of the protection device meets the preset safe tripping conditions, and to execute at least one of the following when the tripping capacity margin of the protection device does not meet the safe tripping conditions: upper level backup protection, current limiting control, distributed power supply current limiting, interruptible load shedding, and topology adjustment. Based on the protection action parameters and the linkage control strategy, adaptive protection control is performed on the target low-voltage power distribution system.

2. The method of claim 1, wherein: The step of constructing a dynamic equivalent impedance network for the target low-voltage power distribution system based on the topology operation data, and determining the expected fault current of a preset candidate fault point under the current operating mode based on the dynamic equivalent impedance network, includes: Based on the topology operation data, the connection relationships and conduction status between the low-voltage busbars, feeder branches, protection devices, load nodes, bus tie switches, tie switches, and controllable power access points in the target low-voltage power distribution system are determined. Based on the connection relationship and the conduction state, a dynamic equivalent impedance network is constructed to characterize the fault current propagation path under the current operating mode; In the dynamic equivalent impedance network, the set of conducting branches between the power supply equivalent point and the candidate fault point is determined, and the equivalent impedance corresponding to the candidate fault point is determined based on the branch impedance in the set of conducting branches, the power supply equivalent impedance, and the local connection impedance corresponding to the candidate fault point. Based on the equivalent impedance, operating voltage, and fault transition impedance corresponding to the candidate fault point, determine the basic fault current of the candidate fault point under the current operating mode; Based on the controllable power supply access status that is electrically connected to the candidate fault point in the dynamic equivalent impedance network, the basic fault current is corrected to obtain the expected fault current of the candidate fault point under the current operating mode.

3. The method of claim 2, wherein: The step of correcting the basic fault current based on the controllable power supply access status that has an electrical connection relationship with the candidate fault point in the dynamic equivalent impedance network to obtain the expected fault current of the candidate fault point under the current operating mode includes: In the dynamic equivalent impedance network, a controllable power source that has a conductive electrical connection with the candidate fault point is identified, and the controllable power source includes at least one of distributed power source and energy storage. The contribution of the controllable power supply to the fault current of the candidate fault point is determined based on the electrical distance between the controllable power supply and the candidate fault point. Based on the basic fault current and the fault current contribution, the expected fault current of the candidate fault point under the current operating mode is determined.

4. The method of claim 1, wherein: The process of dynamically correcting the rated breaking capacity of the protection device based on the protection device parameters, the circuit breaker health status data, and the environmental status data to obtain the actual effective breaking capacity of the protection device under the current operating state includes: Based on the parameters of the protection device, determine the rated ultimate short-circuit breaking capacity and the rated operational short-circuit breaking capacity of the protection device, and determine the basic breaking capacity of the protection device based on the rated ultimate short-circuit breaking capacity and the rated operational short-circuit breaking capacity. Based on the circuit breaker health status data, determine the health status correction coefficient of the protection device caused by at least one of contact wear, short circuit breaking count, contact resistance, terminal temperature rise, and operating mechanism operation status. Based on the environmental condition data, determine the environmental correction factor of the protection device caused by at least one of the following: cabinet temperature, humidity, dust pollution level, and heat dissipation status. Based on the basic breaking capacity, the health status correction coefficient, and the environmental correction coefficient, the rated breaking capacity of the protection device is dynamically corrected to obtain the actual effective breaking capacity of the protection device under the current operating state.

5. The method of claim 1, wherein: The step involves determining the breaking capacity margin of the protection device for the candidate fault point based on the expected fault current and the actual effective breaking capacity, and determining the breaking risk index corresponding to the protection device by combining the fault thermal shock energy corresponding to the candidate fault point and the selectivity relationship between upper and lower level protections, including: The breaking capacity margin of the protection device for the candidate fault point is determined based on the difference between the actual effective breaking capacity of the protection device in the current operating state and the expected fault current of the candidate fault point. The thermal shock energy corresponding to the candidate fault point is determined based on the expected fault current of the candidate fault point and the predicted operating time of the protection device for the candidate fault point. Based on the health status correction coefficient and environmental correction coefficient of the protection device, the ultimate thermal shock withstand capability of the protection device under the current operating state is determined, and the thermal shock margin is determined based on the fault thermal shock energy and the ultimate thermal shock withstand capability. Based on the aforementioned protection selectivity relationship between upper and lower levels, the degree of protection selectivity conflict between the protection device and adjacent protection devices is determined; Based on the breaking capacity margin, the thermal shock margin, and the degree of protection selectivity conflict, the breaking risk index corresponding to the protection device is determined.

6. The method of claim 1, wherein: The step of generating protection action parameters and linkage control strategies based on the fault risk index, the selectivity relationship between upper and lower level protection, and the load importance data includes: The total system failure risk is determined based on the failure risk weight of the candidate failure point, whether the protection device participates in the protection control of the candidate failure point, and the failure risk index. The estimated power outage loss is determined based on the load set affected by the protection action, the load power, the expected power outage duration, and the load importance coefficient. Based on the time difference between upper and lower level protection actions and the difference in protection coordination levels, determine the selective failure penalty; The cost of adjusting the protection settings is determined based on the difference in parameters before and after the adjustment of the protection action parameters. The fault clearance delay penalty is determined based on the relationship between the predicted fault clearance time and the allowed fault clearance time. Based on the total system failure risk, the estimated power outage loss, the selective failure penalty, the protection setting adjustment cost, and the fault clearing delay penalty, an adaptive protection control optimization model is constructed. Under the constraints of breaking capacity safety, thermal shock, upper and lower level protection selectivity, fault clearing time, setting adjustment stability, and load impact, the protection action parameters and the linkage control strategy are generated.

7. The method of claim 4, wherein: After performing adaptive protection control on the target low-voltage power distribution system based on the protection action parameters and the linkage control strategy, the method further includes: Collect protection action feedback data, which includes at least one of the following: actual fault current peak value, actual fault current duration, actual protection device operation time, contact temperature rise change, arc duration, disconnection success status, failure to operate status, over-level trip status, and power outage range. Based on the actual fault current peak value and the actual fault current duration, determine the actual thermal shock energy that the protection device withstands during this protection operation; Based on the actual thermal shock energy, the temperature rise change of the contact, the duration of the arc, the actual action time of the protection device, and the successful disconnection status, the degree of state deterioration of the protection device after this protection action is determined. Based on the aforementioned state deterioration amount, the health state correction coefficient corresponding to the protection device is updated; The actual effective breaking capacity of the protection device is updated based on the updated health status correction coefficient, and the breaking capacity margin and breaking risk index are updated based on the updated actual effective breaking capacity.

8. A high breaking capacity adaptive protection control device for low voltage distribution systems, characterized by: The device includes: The data acquisition module is used to acquire multi-source status data of the target low-voltage power distribution system. The multi-source status data includes topology operation data, protection device parameters, circuit breaker health status data, environmental status data, and load importance data. The fault current determination module is used to construct a dynamic equivalent impedance network of the target low-voltage power distribution system based on the topology operation data, and determine the expected fault current of the preset candidate fault point under the current operation mode according to the dynamic equivalent impedance network. The breaking capacity determination module is used to dynamically correct the rated breaking capacity of the protection device based on the protection device parameters, the circuit breaker health status data and the environmental status data, so as to obtain the actual effective breaking capacity of the protection device under the current operating state. The breaking risk determination module is used to determine the breaking capacity margin of the protection device for the candidate fault point based on the expected fault current and the actual effective breaking capacity, and to determine the breaking risk index corresponding to the protection device by combining the fault thermal shock energy corresponding to the candidate fault point and the selectivity relationship between the upper and lower level protections. The linkage control determination module is used to generate protection action parameters and linkage control strategies based on the tripping risk index, the selectivity relationship between upper and lower level protections, and the load importance data. The linkage control strategy is used to maintain the lower level protection with priority when the tripping capacity margin of the protection device meets the preset safe tripping conditions, and to execute at least one of the following when the tripping capacity margin of the protection device does not meet the safe tripping conditions: upper level backup protection, current limiting control, distributed power supply current limiting, interruptible load shedding, and topology adjustment. The protection control execution module is used to perform adaptive protection control on the target low-voltage power distribution system based on the protection action parameters and the linkage control strategy.

9. An electronic device, comprising: The electronic device includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the method as described in any one of claims 1-7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer-readable storage medium stores computer-executable instructions for performing the method as described in any one of claims 1-7.

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