Adaptive short-circuit fault current limiting control method and system for primary and secondary hybrid circuit breaker

Abstract

The application provides a self-adaptive short-circuit fault current limiting control method and system of a secondary fusion circuit breaker, relates to the technical field of circuit protection and manufacturing, and comprises the following steps: collecting current values, voltage values and circuit breaker state quantities to form a first operating parameter set; performing feature extraction based on amplitude mutation, phase offset and harmonic components, generating a first feature vector, matching the first feature vector with a preset short-circuit fault feature template, obtaining a fault recognition result and a fault type and location identifier; calculating a dynamic current limiting control curve according to the identifier and the current values, generating a current limiting control parameter set, controlling a current limiting execution mechanism to obtain current limiting response data; collecting a second operating parameter set after the action is completed, performing current limiting effect analysis to generate state feedback data, and updating the current limiting control parameter set based on the feedback data; and performing factory calibration on a power electronic current limiting module serving as the current limiting execution mechanism. The method improves the adaptive ability and precision of current limiting control.

Description

Technical Field

[0001] This application relates to the field of circuit protection and manufacturing technology, and more specifically, to an adaptive short-circuit fault current limiting control method and system for primary and secondary integrated circuit breakers. Background Technology

[0002] In the power distribution network sector, integrated primary and secondary circuit breakers, as a key component of pole-mounted equipment, integrate current and voltage measurement, communication, and control functions to achieve line protection and fault isolation. However, existing short-circuit fault current-limiting control methods mostly rely on fixed thresholds or preset action curves, lacking flexibility in real-time response to fault currents. In outdoor operating environments, short-circuit faults exhibit significant diversity, with characteristics such as waveform abrupt changes, phase shifts, and harmonic interference caused by phase-to-phase short circuits or single-phase grounding coexisting. Existing methods struggle to dynamically adjust based on fault type, fault location, and system operating status, easily leading to delayed, excessive, or insufficient current-limiting actions. This can expand the fault's impact range, increase equipment thermal stress accumulation, and potentially affect the power supply reliability and structural safety of downstream power grids. Furthermore, with the increasing application of power electronic current-limiting modules in current-limiting actuators, the consistency of module manufacturing, the matching relationship between factory calibration parameters and field control strategies directly impacts current-limiting accuracy. However, existing solutions typically lack parameter constraints and invocation mechanisms oriented towards manufacturing and factory calibration, resulting in accumulated deviations between control parameters and actual responses. Meanwhile, the intelligent management level of existing integrated primary and secondary circuit breakers is limited. After the current limiting process, there is a lack of effective effect evaluation and parameter optimization mechanisms, still requiring manual inspection and on-site maintenance, making continuous improvement under unattended conditions difficult. Therefore, how to improve the adaptive capability and accuracy of current limiting control in integrated primary and secondary circuit breakers when short-circuit faults occur, while simultaneously achieving feedback-based continuous optimization to reduce the impact of faults, has become a pressing technical problem to be solved in this field. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this application provides an adaptive short-circuit fault current limiting control method and system for primary and secondary integrated circuit breakers.

[0004] In a first aspect, this application provides an adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker, including:

[0005] Collect the current and voltage values ​​of the power distribution lines and the status parameters of the circuit breakers to obtain the first set of operating parameters;

[0006] Based on the first set of operating parameters, feature extraction operations are performed on the amplitude abrupt change, phase offset, and harmonic components of the current waveform to generate the first feature vector;

[0007] Based on the first feature vector, a preset short-circuit fault feature template is matched to determine the short-circuit fault identification result, and a fault type identifier and a fault location identifier are generated.

[0008] Based on the fault type identifier, fault location identifier, and current value in the first set of operating parameters, calculate the dynamic current limiting control curve for the fault type and fault location, and generate the current limiting control parameter set.

[0009] Based on the set of current limiting control parameters, the current limiting actuator of the circuit breaker is controlled to perform current limiting and generate current limiting response data.

[0010] After the current limiting action is completed, the status variables of the circuit breaker and the current value of the line are collected to generate a second set of operating parameters;

[0011] The flow limiting effect is analyzed based on the second set of operating parameters, and status feedback data is generated; the flow limiting control parameter set is updated based on the status feedback data.

[0012] Optionally, generating the first feature vector includes:

[0013] Empirical mode decomposition is performed on the collected current values, which are decomposed into multiple intrinsic mode functions and a residual component;

[0014] The residual component was identified as the transient DC component in the short-circuit current;

[0015] Subtract the transient DC component from the collected current value to obtain the pure AC fault current.

[0016] Based on the pure AC fault current, feature extraction operations are performed on amplitude, phase, and harmonics to generate the first feature vector.

[0017] Optionally, performing empirical mode decomposition on the acquired current values, decomposing them into multiple intrinsic mode functions and a residual component, includes:

[0018] A phase-aligned analysis window is constructed starting from the first power frequency zero-crossing determined based on the voltage value, and a phase-locked mirror extension is performed on both ends of the analysis window to obtain the current analysis sequence.

[0019] Based on the current analysis sequence, upper and lower envelopes are constructed according to local extreme points and the mean value of the envelope is calculated to perform screening iteration. The iteration stopping condition of the screening is set to the energy change within the power frequency tracking bandwidth being lower than a preset first threshold.

[0020] During the screening process, a monotonically decaying constraint is applied to the residual component. The decay rate is calculated based on the ratio of the equivalent reactance to the resistance of the primary circuit of the circuit breaker and the phase difference between the voltage phase and the current phase.

[0021] When the monotonic decay constraint is satisfied and the instantaneous frequency of each intrinsic mode function falls on the high-frequency side outside the power frequency tracking bandwidth, the set of intrinsic mode functions and residual components are output.

[0022] Optionally, performing empirical mode decomposition on the acquired current values ​​includes:

[0023] A mechanical interference mask sequence is generated based on the contact open / close position signal and coil drive timing in the circuit breaker state variables.

[0024] During the screening iteration process, weighted suppression is applied to the local extreme points of the upper and lower envelopes according to the mechanical interference mask sequence to reduce the mechanical coupling components from entering the residual components.

[0025] A DC polarity reference is established based on the voltage phase and current polarity at the fault initiation time, and a DC polarity identifier is generated.

[0026] After screening, a DC reliability index is generated based on the energy ratio of the residual component within the power frequency tracking bandwidth and the overlap ratio of the mechanical interference mask.

[0027] The DC polarity identifier and DC confidence index are output along with the intrinsic mode function set and residual components for feature extraction and short-circuit fault identification.

[0028] Optionally, the generation of the mechanical interference mask sequence based on the contact open / close position signal and coil drive timing in the circuit breaker state variables includes:

[0029] The closing or opening trigger time is determined from the coil drive timing, and the stable positioning time is determined from the contact opening / closing position signal, thus establishing the time interval from the start of the action to the stable positioning.

[0030] The time interval is divided into an electromagnetic acceleration segment, a contact collision segment, and a contact bounce segment. The first flip of the contact opening / closing position signal is defined as the starting point of the contact collision segment, and the last flip is defined as the ending point of the contact bounce segment.

[0031] A mask sequence is generated within the time interval with a sampling interval consistent with the current analysis sequence. The first suppression level is marked in the electromagnetic acceleration segment and the contact bounce segment, the second suppression level is marked in the contact collision segment, and zero suppression is marked outside the time interval.

[0032] The output mechanical interference mask sequence and segment boundary index are used to apply weighted suppression to local extrema of the upper and lower envelopes during the sieving iteration.

[0033] Optionally, the set of current limiting control parameters includes:

[0034] Calculate the predicted time of the next power frequency zero crossover based on the voltage values ​​in the first set of operating parameters;

[0035] Based on the circuit breaker status variables in the first set of operating parameters, determine the action delay parameters of the current limiting actuator;

[0036] A zero-crossing aligned control time grid is constructed using the predicted time and the action delay parameter;

[0037] On the control time grid, the switching time and tripping trigger window of the controllable impedance stage are determined according to the peak value and short-time root mean square value of the current value in the first set of operating parameters.

[0038] The output consists of a set of current limiting control parameters, which are composed of a time grid vector, an impedance level identifier vector, and a trigger window threshold.

[0039] Optionally, the determination of the action delay parameters of the current limiting actuator includes:

[0040] The trigger time of the action is determined based on the coil drive timing, and the coil current waveform and contact opening / closing position signal are obtained under the same time reference.

[0041] The slope change and back EMF dip characteristics of the coil current waveform are detected to locate the release feature point and obtain the electromagnetic release delay.

[0042] The time difference between the first stable flip of the contact opening / closing position signal and the release feature point is used as the opening distance establishment delay;

[0043] The time difference between the last flip of the contact open / close position signal and the stable position is taken as the stable position delay;

[0044] Based on the state variables of the control power supply voltage and ambient temperature, the electromagnetic release delay, the opening gap establishment delay, and the stable positioning delay are corrected by temperature and pressure, and the action delay parameter composed of the electromagnetic release delay, the opening gap establishment delay, and the stable positioning delay is output.

[0045] Optionally, the step of performing flow limiting effect analysis based on the second set of operating parameters and generating status feedback data includes:

[0046] The completion time of the current limiting action is determined based on the circuit breaker status variables in the second set of operating parameters, and an evaluation window is established in the adjacent power frequency cycle after that time.

[0047] Within the evaluation window, the peak value, short-time root mean square value, and current square time integral value of the current values ​​in the second set of operating parameters are calculated to generate a set of electrical load parameters.

[0048] The power frequency tracking result is obtained based on the voltage value in the second set of operating parameters. The amplitude ratio of the fundamental component to the odd harmonic component is calculated within the evaluation window, and the remaining proportion of the transient DC component is estimated. The amplitude ratio, the remaining proportion, and the set of electrical load parameters are combined into state feedback data.

[0049] Optionally, it also includes: performing manufacturing and factory calibration on the power electronic current limiting module that is the current limiting actuator or constitutes part of the current limiting actuator, the manufacturing and factory calibration including:

[0050] The power switching device unit, the controllable impedance network unit, and the drive and protection unit are assembled and electrically connected to form the power electronic current limiting module;

[0051] A standardized current limiting excitation is applied to the power electronic current limiting module on the test fixture, and the module voltage, module current, drive timing and module temperature status are collected simultaneously to obtain the set of factory test operation parameters.

[0052] Based on the set of factory test operation parameters, the action delay parameters of the power electronic current limiting module are determined, and the equivalent parameters of each impedance level of the controllable impedance network unit are determined.

[0053] Based on the action delay parameters and the equivalent parameters of each impedance level, a set of factory calibration parameters is generated, and the set of factory calibration parameters is written into the storage unit of the power electronic current limiting module and / or the parameter storage area of ​​the circuit breaker controller. The set of factory calibration parameters is used to construct a zero-crossing aligned control time grid and determine the switching time and tripping trigger window of the controllable impedance level when the current limiting control parameter set is generated.

[0054] Secondly, this application provides an adaptive short-circuit fault current limiting control system for a primary and secondary integrated circuit breaker, including:

[0055] The data acquisition module is used to collect the current value, voltage value, and circuit breaker status of the power distribution line to obtain the first set of operating parameters;

[0056] The first processing module performs feature extraction operations on the amplitude abrupt change, phase offset and harmonic components of the current waveform based on the first set of operating parameters to generate a first feature vector; it matches the first feature vector with a preset short-circuit fault feature template to determine the short-circuit fault identification result and generates a fault type identifier and a fault location identifier.

[0057] The second processing module calculates a dynamic current limiting control curve for the fault type and the fault location based on the fault type identifier, the fault location identifier, and the current value in the first set of operating parameters, and generates a set of current limiting control parameters.

[0058] The control module is used to control the current limiting actuator of the circuit breaker to perform current limiting based on the set of current limiting control parameters, and to generate current limiting response data.

[0059] The feedback module is used to collect the status variables of the circuit breaker and the current value of the line after the current limiting action is completed, and generate a second set of operating parameters; perform current limiting effect analysis based on the second set of operating parameters, and generate status feedback data; and update the current limiting control parameter set based on the status feedback data.

[0060] Compared with existing technologies, this application establishes a clear mapping relationship between current limiting control and actual fault characteristics and locations by forming a closed-loop control chain: data acquisition, feature extraction, template matching and identification, dynamic current limiting curve calculation based on type and location, current limiting execution, secondary data acquisition and effect analysis, and feedback-based parameter update. After the action, on-site measurements drive parameter updates, reducing the impact of model mismatch on the consistency of subsequent actions. This improves the distinguishability and location accuracy of fault identification, reduces the accumulation of thermal and mechanical stress caused by excessive or insufficient current limiting, enhances stability and selective coordination under changing operating conditions, and achieves continuous internal tuning of the device without relying on external systems. Attached Figure Description

[0061] Figure 1 A flowchart of the adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker provided in this application embodiment;

[0062] Figure 2 A flowchart illustrating a method for generating a first feature vector provided in an embodiment of this application;

[0063] Figure 3 A flowchart illustrating a method for performing empirical mode decomposition on acquired current values, provided in an embodiment of this application;

[0064] Figure 4 A schematic diagram of an adaptive short-circuit fault current limiting control system for a primary and secondary integrated circuit breaker provided in this application embodiment. Detailed Implementation

[0065] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0066] See Figure 1 The diagram shows a flowchart of an adaptive short-circuit fault current limiting control method for a primary and secondary fusion circuit breaker provided in this application embodiment, including steps S101 to S106, wherein:

[0067] S101: Collect the current value, voltage value and circuit breaker status of the power distribution line to obtain the first set of operating parameters;

[0068] S102: Based on the first set of operating parameters, perform feature extraction operations on the amplitude abrupt change, phase offset, and harmonic components of the current waveform to generate a first feature vector;

[0069] S103: Based on the first feature vector, match the preset short-circuit fault feature template to determine the short-circuit fault identification result, and generate the fault type identifier and fault location identifier;

[0070] S104: Based on the fault type identifier, fault location identifier, and current value in the first set of operating parameters, calculate the dynamic current limiting control curve for the fault type and the fault location, and generate a set of current limiting control parameters.

[0071] S105: Based on the set of current limiting control parameters, control the current limiting actuator of the circuit breaker to perform current limiting and generate current limiting response data;

[0072] S106: After the current limiting action is completed, the status variables of the circuit breaker and the current value of the line are collected to generate a second set of operating parameters; the current limiting effect analysis is performed based on the second set of operating parameters to generate status feedback data; the current limiting control parameter set is updated based on the status feedback data.

[0073] Regarding the above S101:

[0074] When a short-circuit fault occurs, the current and voltage of the distribution line exhibit significant non-stationary characteristics within a very short time, and the circuit breaker mechanism state also changes within milliseconds. If the current value, voltage value, and circuit breaker state quantity are not obtained synchronously or are not recorded with a unified time reference, the subsequent feature extraction of amplitude abrupt changes, phase shifts, and harmonic components will lack a consistent reference, easily introducing timing misalignment and phase confusion, thereby affecting the accuracy of fault identification results and subsequent current limiting control calculations.

[0075] Therefore, it is necessary to synchronously record and align the current sampling sequence, voltage sampling sequence, and state events under a unified time reference to form a first set of operating parameters containing necessary fields, which will serve as the input for all subsequent processing stages.

[0076] The first set of operating parameters refers to a set of structured data such as current sampling sequences, voltage sampling sequences, and circuit breaker status events obtained under a unified time base, which includes at least fields such as sampling start timestamp, sampling interval, number of sampling points, phase reference information, phase sequence identifier, and status event table.

[0077] In a primary and secondary integrated circuit breaker, the current sampling channel, voltage sampling channel, and status quantity acquisition channel share the same time base. The current sampling channel acquires the analog quantity of the line current through a primary side current sensing scheme. After signal conditioning and isolation, it enters analog-to-digital conversion to form an equally spaced current sampling sequence. The voltage sampling channel acquires the analog quantity of the line voltage through voltage divider sampling, and forms an equally spaced voltage sampling sequence through the same process. The status quantity acquisition channel includes edge capture of discrete quantities such as coil drive timing and contact opening / closing position signals, as well as low-speed sampling of mechanism travel, vibration, or environmental quantities. All events and samples are indexed using the same time base.

[0078] The phase reference point is extracted from the voltage sampling sequence and serves as a common phase anchor point for the current and voltage paths. Fixed-length current and voltage sampling segments are extracted around the phase reference point and correlated with a state event table on the same time axis to obtain a complete and time-aligned dataset. This dataset is directly used in subsequent steps for feature extraction of amplitude abrupt changes, phase shifts, and harmonic components, independent of any specific threshold settings or calculation formulas.

[0079] The phase reference point refers to the time reference point extracted from the voltage sampling sequence for phase alignment, which serves as a common phase anchor point for the current and voltage paths in subsequent processing.

[0080] A sampling segment refers to a fixed-length, equally spaced sequence of current and voltage samples taken around a phase reference point, which is used for subsequent feature extraction.

[0081] A status event table refers to a set of circuit breaker status events recorded with a unified time base. It includes at least the event type, the event start index, and the event end index, and is used to represent the position range of status changes such as coil drive and contact open / close position on the time axis.

[0082] For example, the device is configured with a current sampling channel, a voltage sampling channel, and a status acquisition channel, all of which are controlled and operate synchronously by a unified time reference. The voltage sampling channel is used to generate a phase reference point, and the current sampling channel and the voltage sampling channel form two sampling sequences with equal intervals. The status acquisition channel captures the edges of coil drive and contact opening / closing position changes and records the event start and end indices.

[0083] In the acquisition process of this embodiment, after the device detects a new phase reference point, it extracts a fixed-length current sampling segment and a voltage sampling segment around the reference point. Within the same time range, events such as the rising edge and falling edge of the coil drive and the flipping of the contact opening and closing position are written into the state event table and described by event type, event start index and event end index.

[0084] After completing the above extraction and recording, the system generates a first set of operating parameters. This set includes at least: sampling start timestamp, sampling interval, number of sampling points, current sampling sequence, voltage sampling sequence, phase reference index, phase sequence identifier, state event table, and device operating mode identifier. This set achieves channel alignment and field completeness under a unified time reference and can be directly used as input for subsequent feature extraction and recognition calculations.

[0085] The device operating mode identifier field indicates whether the circuit breaker is in an open, closed, or standby operating state, and is used to identify the current operating condition within the same time reference.

[0086] Regarding S102:

[0087] After a short-circuit fault is triggered, the current sampling sequence simultaneously exhibits abrupt amplitude changes, rapid phase drift, and an increase in harmonic components, often accompanied by transient DC components coupled with mechanical motion interference. If these components are not distinguished and calculable features are not extracted under a unified time reference, template-based fault identification will be difficult to execute stably. Therefore, a feature extraction process for the current sampling sequence under a unified time reference needs to be provided, explicitly quantifying the amplitude abruptness, phase shift, and harmonic features to form a structured first feature vector.

[0088] Under a unified time reference, the current sampling sequence and voltage sampling sequence in the first set of operating parameters are read, and the two sequences are phase-aligned using a phase reference point.

[0089] Optional, see Figure 2 The flowchart below shows a method for generating a first feature vector according to an embodiment of this application, including steps S201 to S204, wherein:

[0090] S201: Perform empirical mode decomposition on the acquired current value, decomposing it into several intrinsic mode functions and a residual component;

[0091] S202: Identify the residual component as a transient DC component in the short-circuit current;

[0092] S203: Subtract the transient DC component from the collected current value to obtain the pure AC fault current.

[0093] S204: Based on the pure AC fault current, perform feature extraction operations on amplitude, phase and harmonics to generate the first feature vector.

[0094] First, empirical mode decomposition is performed on the current sampling sequence. The residual component obtained is identified as a transient DC component. The residual component is then subtracted from the current sampling sequence to obtain the pure AC fault current.

[0095] Amplitude mutation features are extracted from pure AC fault current. By analyzing the difference between adjacent samples and detecting local extrema in the sampling sequence, the sample index where the mutation occurred is located. The amplitude change and the number of samples with duration of change are statistically analyzed within several samples before and after the mutation, forming fields such as mutation time, mutation amplitude, and duration.

[0096] Phase offset features are extracted using the voltage sampling sequence as the phase reference. Phase tracking is performed on the pure AC fault current, mapping the current phase at each sampling point to the same angular domain as the phase reference to obtain the phase offset sequence. Fields such as initial phase value, phase change, and phase stability are then extracted from this sequence.

[0097] Harmonic characteristics are extracted from the frequency domain analysis results of pure AC fault current. Spectral analysis is performed on the phase-aligned sampling segments to read the amplitude or amplitude ratio of the fundamental component and several odd harmonic components, obtaining the harmonic amplitude vector and its ordered index.

[0098] The three types of features are concatenated in a fixed field order to obtain the first feature vector. The fixed field order is as follows: amplitude mutation feature field, phase shift feature field, and harmonic feature field; the field order remains unchanged in each processing step to ensure the stability of the vector dimension and field meaning.

[0099] In practical implementation, the device reads the current sampling sequence, voltage sampling sequence, and phase reference index from the first set of operating parameters, and extracts a sampling segment of fixed length around the phase reference index. Empirical mode decomposition is performed on the current sampling segment, outputting several intrinsic mode functions and residual components. The residual components are treated as transient DC components and subtracted from the current sampling segment to obtain the pure AC fault current.

[0100] On the same segment, amplitude mutation features are first generated: based on sample differences and local extrema, mutation sample index is determined, and the amplitude change and the number of samples with change duration on both sides of the mutation sample index are recorded to form three fields: "mutation sample index, mutation amplitude, and mutation duration".

[0101] Then, phase offset features are generated: using the voltage sampling segment as the phase reference, the offset sequence between the current phase and the phase reference is obtained, and the three fields of "initial phase value, phase change amount, and phase stability" are extracted from it.

[0102] Finally, harmonic features are generated: frequency domain analysis is performed on the sampled segment of pure AC fault current, and the amplitude or amplitude ratio of the fundamental component and several odd harmonic components is read to form a field group of "fundamental amplitude, odd harmonic amplitude ratio vector and its ordered index".

[0103] The above fields are concatenated in a fixed order of "amplitude mutation feature - phase shift feature - harmonic feature" to obtain the first feature vector corresponding to the segment, and saved together with the phase reference index of the segment for subsequent steps.

[0104] Among them, the amplitude mutation feature indicates the set of instantaneous amplitude changes of the current sequence near the fault trigger, the number of samples with the duration of the change, and the sample index of the mutation.

[0105] Phase offset refers to the amount of deviation of the current phase relative to the phase reference, with the voltage sequence as the phase reference. It can include the initial value, the amount of change, and the stability index.

[0106] Harmonic components refer to the characteristic set of the amplitudes or amplitude ratios of the sequence harmonic components other than the fundamental frequency.

[0107] The pure AC fault current refers to the AC component sequence obtained after performing empirical mode decomposition on the current sampling sequence and identifying the residual components as transient DC components.

[0108] The first feature vector refers to the vector representation after encoding the amplitude abrupt change feature, phase shift feature, and harmonic feature according to the preset field order.

[0109] Regarding the above S103:

[0110] In short-circuit fault scenarios, the current sequence simultaneously exhibits non-stationary characteristics such as abrupt amplitude changes, phase shifts, and harmonic variations. Relying solely on a single indicator for identification can easily lead to type confusion or location ambiguity. Therefore, under a unified time reference, the first feature vector obtained in step S102 needs to be matched with a preset feature template. This ensures that the determination of fault type and location is based on the consistency of multi-dimensional features, resulting in stable fault type and location identifiers.

[0111] The following is an explanation of some terms used in this application:

[0112] A short-circuit fault feature template refers to a record unit formed based on the summary of typical fault conditions. It includes a template number, fault type code, location segmentation code, and a set of template feature fields that correspond one-to-one with the first feature vector field.

[0113] Fault type identifiers are codes used to distinguish different types of faults, such as single-phase grounding, phase-to-phase short circuit, two-phase grounding, and three-phase short circuit, and are recorded in code form.

[0114] Fault location identifiers refer to codes used to indicate feeder segments or distance boxes, which correspond to the line topology and are recorded by segment number or section code.

[0115] The matching result refers to the sorting result obtained by comparing the first feature vector with the template feature fields item by item, including at least the best template number and its matching order position.

[0116] In practice, the template library is cataloged according to the "type code-location code" format. The feature fields of each template record are consistent with the fields of the first feature vector, and the field order is consistent. The template feature fields are derived from the statistical results of phase-aligned segments during the device's commissioning phase, experimental platform, or historical operating conditions, and are stored in the device's non-volatile storage area. Line segmentation and location codes are pre-set based on existing topology data.

[0117] After receiving the first feature vector, the device performs field alignment and channel consistency checks, comparing the amplitude mutation feature, phase shift feature and harmonic feature in the vector with the same template field in groups; the comparison results of each field group are weighted and summarized to form a matching degree ranking for each template; when templates with adjacent position codes are adjacent in the ranking and have the same type code, the position continuity rule is used to perform parallel elimination to obtain a unique best template number.

[0118] Furthermore, the type code and location code are directly read from the optimal template number and output as the fault type identifier and fault location identifier, respectively; at the same time, the matching order position and template number are recorded together for reference in subsequent steps.

[0119] For example, in one embodiment, the template library is divided into several position segments according to the feeder from the power supply side to the end. Each segment establishes a template record under four categories: single-phase grounding, phase-to-phase short circuit, two-phase grounding, and three-phase short circuit. The feature fields of the template record correspond one-to-one with the first feature vector, including at least: a mutation sample index and duration, amplitude change field group; initial phase value, phase change amount, and stability field group; and a field group of fundamental amplitude and several odd harmonic amplitude ratios.

[0120] After obtaining the first feature vector of a fault, the device first compares it with each record in the template library in order of field sequence to obtain a set of matching degree rankings. The ranking results show that a certain "phase-to-phase short circuit - middle section" template is ranked first, and the template of the same type in its adjacent section is ranked second. The device confirms the first template as the best template according to the position continuity rule, reads the type code and position code in it, outputs them as the fault type identifier and fault position identifier respectively, and records the template number and its ranking position.

[0121] Regarding S104 above:

[0122] After identifying the fault type and location, a mapping relationship needs to be established between the identification results and the current current change characteristics to form a dynamic current limiting control curve that can directly drive the current limiting actuator. Based on this, a set of current limiting control parameters is generated. This curve should reflect the phased requirements of initial fault suppression, transitional stabilization, and recovery phase exit, ensuring that the control objective matches the fault characteristics and location conditions.

[0123] The dynamic current limiting control curve indicates the description of the control target changing over time in segments, including at least three types of target descriptions: initial suppression segment, transition segment, and recovery segment, which are used to constrain the actions of the current limiting actuator in each segment.

[0124] The current limiting control parameter set refers to the structured parameter set used to drive the actuator, which includes at least three parts: stage sequence description, stage switching flag, and target envelope description.

[0125] The target envelope description refers to the set of fields that encode the way the current target changes within each stage, and is used to limit the trend of the control target's change within that stage.

[0126] In practical implementation, after receiving the fault type identifier and fault location identifier, the device selects a basic control mode from a preset control strategy library that matches the type and location. The basic control mode provides a phase sequence and their relative order. The device reads the current values ​​from the first set of operating parameters, extracts the current change characteristics related to the fault initiation, and uses these features to normalize and adapt the basic control mode, ensuring that the target envelope description is consistent with the current operating condition.

[0127] After the basic control mode is determined, the device generates corresponding stage switching markers based on the stage sequence in that mode, and generates a target envelope description for each stage. The target envelope description characterizes the change pattern of the target within a stage in coded form; the stage switching markers are used to define the boundary conditions between adjacent stages; and the stage sequence description is used to indicate the overall control progression order. Through the above steps, a higher-level description of the dynamic current-limiting control curve is formed and output in the form of a set of current-limiting control parameters.

[0128] For example, the fault type identifier indicates a phase-to-phase short circuit, and the fault location identifier indicates a section in the middle of the feeder. The device selects the corresponding basic control mode from the strategy library. The basic control mode includes a phase sequence of "initial suppression - transition stabilization - recovery exit". The device reads the current value from the first set of operating parameters, extracts the current rise characteristics near the fault initiation, and adapts the basic control mode accordingly to obtain a target envelope description for this type and location. Subsequently, the device generates a phase switching flag according to the basic control mode, and combines the phase sequence description, the phase switching flag, and the target envelope description to form a current limiting control parameter set.

[0129] In another embodiment, the fault type identifier indicates a single-phase ground fault and the location identifier is located at the end of the feeder section. The device also selects the corresponding basic control mode from the strategy library, but the continuous requirement for initial stage suppression in the stage sequence differs from the stability requirement for the transition stage. After adapting based on the current values ​​in the first set of operating parameters, the device outputs a set of current-limiting control parameters containing the corresponding stage sequence description, stage switching flag, and target envelope description.

[0130] Regarding the above S105:

[0131] Once a set of current-limiting control parameters has been generated, it is necessary to convert this parameter set into control commands that can be recognized by the actuator, and to complete the current-limiting action under phased target constraints. Simultaneously, it is necessary to record key moments and measured quantities during the action process to generate current-limiting response data for subsequent analysis.

[0132] Among them, the current limiting actuator can be a mechanism coupled to the circuit breaker body for implementing current limiting actions, and can respond to control commands issued by the control layer.

[0133] The control commands are an execution layer instruction set translated from the current limiting control parameter set through the interface layer, which is used to drive the actuator to perform actions in a phase sequence.

[0134] The current limiting response data reflects the recorded data of the current limiting action implementation process, including at least the actual time of stage switching, changes in the state of the actuator, and current measurement segments during the action process.

[0135] In practice, the control layer reads the stage sequence description, stage switching flag, and target envelope description from the current limiting control parameter set, and converts them into control commands through the interface layer. The interface layer issues commands to the actuators under a unified time reference and confirms the status at each stage boundary. During execution, the system records changes in the actuator's state variables according to a preset sampling scheme, and simultaneously captures current sampling segments at critical moments to form measured quantity records corresponding to each stage. After the action is completed, the actual time of stage switching, the actuator state change records, and the concurrent current segments are combined to form the current limiting response data.

[0136] Regarding S106 above:

[0137] After the current limiting action is completed, the current and state variables after the action need to be acquired under a unified time reference to evaluate the degree of conformity between the action and the target, and the control parameters used for subsequent actions should be updated accordingly to ensure that the control process is consistent with the field conditions.

[0138] The second set of operating parameters is a structured data set collected after the current limiting action is completed, which includes at least the current sampling sequence, circuit breaker status entries and their time index information.

[0139] Current limiting effect analysis refers to evaluating the degree of conformity between the current change after the action and the stage target based on the second set of operating parameters, and outputting indicator data for updating.

[0140] The status feedback data is a structured output obtained from the flow limiting effect analysis, which includes at least deviation-related fields and stage achievement-related fields.

[0141] Parameter update refers to the process of adjusting relevant parameter items in the current limiting control parameter set based on status feedback data.

[0142] In practice, after the action completion signal is confirmed, the system initiates a post-acquisition process under a unified time reference. This process acquires a current sampling sequence containing several sampling intervals after the action is completed, along with synchronously recorded state variable entries, forming a second set of operating parameters. Based on this set, the effect analysis module reads the sampling intervals corresponding to the stage sequence, evaluates the corresponding intervals according to the target envelope description, and generates state feedback data for updating. The parameter update module adjusts the relevant parameter items in the current limiting control parameter set based on the state feedback data, completing one update.

[0143] For example, after the action completion signal is confirmed, the system extracts a current sampling sequence with a fixed-length sampling interval and simultaneously records the static positioning state of the actuator, generating a second set of operating parameters. The effect analysis module reads the sampling intervals corresponding to the three-stage sequence, performs comparative evaluations respectively, and outputs status feedback data containing deviation and stage achievement fields. The parameter update module receives this status feedback data and adjusts the time-related, action-related, and threshold-related items in the current limiting control parameter set in one go, forming an updated current limiting control parameter set for subsequent actions.

[0144] In its implementation, this application defines an operating cycle as the sequence of steps S101 to S106 experienced during a single fault handling operation. The starting point of the operating cycle is the first set of operating parameters generated in step S101, and the ending point is the update of the current limiting control parameter set completed in step S106 based on the status feedback data. After the operating cycle ends, the updated set of current limiting control parameters is marked as the currently effective parameter set for subsequent fault handling.

[0145] Upon the next fault trigger, the device re-executes steps S101 to S104. In step S104, when selecting and adapting the basic control mode, the currently effective parameter set is invoked to participate in the generation of the dynamic current limiting control curve. In step S105, a current limiting action is implemented based on the new current limiting control parameter set, generating current limiting response data. In step S106, after the action is completed, a second operating parameter set is generated and status feedback data is output, subsequently updating the currently effective parameter set. This forms a closed loop of identification-generation-execution-evaluation-update.

[0146] In another embodiment, when step S106 does not obtain status feedback data that meets the update conditions, or when the validity of the status feedback data is insufficient to support parameter adjustment, the device keeps the current effective parameter set unchanged, the operation cycle ends in a "hold" manner, and waits for the next fault trigger to re-enter step S101.

[0147] Furthermore, directly performing empirical mode decomposition on the current sampling sequence during a fault is susceptible to endpoint effects and frequency drift, leading to mode aliasing or residual components carrying fundamental and high-frequency components during the screening process, thus affecting the identification of transient DC components. Therefore, it is necessary to construct an analysis window with a time reference consistent with the grid phase to suppress endpoint effects, and to constrain the screening iteration and the form of the residual components using a criterion related to the grid power frequency, so that the output intrinsic mode function and residual components meet the specified conditions.

[0148] Optional, see Figure 3 The flowchart of an empirical mode decomposition method for collecting current values, provided in an embodiment of this application, includes steps S301 to S304, wherein:

[0149] S301: Construct a phase-aligned analysis window starting from the first power frequency zero-crossing determined based on the voltage value, and perform phase-locked mirror extension on both ends of the analysis window to obtain the current analysis sequence;

[0150] S302: Based on the current analysis sequence, construct upper and lower envelopes according to local extreme points and calculate the envelope mean to perform sieving iteration. The sieving iteration stopping condition is set to the energy change within the power frequency tracking bandwidth being lower than a preset first threshold.

[0151] S303: A monotonically decaying constraint is applied to the residual component during the screening process. The decay rate is estimated based on the ratio of the equivalent reactance to the resistance of the primary circuit of the circuit breaker and the phase difference between the voltage phase and the current phase.

[0152] S304: When the monotonic decay constraint is satisfied and the instantaneous frequency of each intrinsic mode function falls on the high-frequency side outside the power frequency tracking bandwidth, output the intrinsic mode function set and residual components.

[0153] The phase-aligned analysis window is a time segment established starting from the first power frequency zero-crossing determined based on the voltage value, used for segmented analysis of the current sequence.

[0154] Phase-locked mirror extension is an endpoint processing method that extends the image at both ends of the analysis window while maintaining the same phase, in order to alleviate the endpoint effect during decomposition.

[0155] The sieving iteration is a loop process that constructs upper and lower envelopes based on local extreme points, calculates the mean of the envelopes, and subtracts it from the current sequence. This process is used to extract intrinsic mode functions.

[0156] The power frequency tracking bandwidth is a frequency neighborhood established around the power frequency, used to determine whether the intrinsic mode function and residual components fall near the fundamental frequency.

[0157] Monotonic decay constraint is a shape constraint applied to the residual component during the sieving process, requiring its envelope amplitude to decrease monotonically with time, in order to characterize transient DC characteristics.

[0158] In practice, the first power frequency zero-crossing is determined from the voltage sampling sequence and used as the starting point of the analysis window. To reduce the end-point effect, phase-locked mirror extensions are performed at both ends of the analysis window to ensure that the extended segment is phase-continuous with the inside of the window, thus obtaining the current analysis sequence for decomposition.

[0159] The current analysis sequence is subjected to a screening iteration. In each iteration, upper and lower envelopes are constructed based on local extrema, and the mean of the envelope is calculated. The mean of the envelope is subtracted from the current sequence to obtain candidate intrinsic components. When the energy change within the power frequency tracking bandwidth is lower than a preset threshold, the screening is deemed to have met the stopping condition, and an intrinsic mode function is output. Subsequently, the remaining sequence is used as the new input to continue screening until the output condition is met.

[0160] During the screening process, a monotonically decaying constraint is applied to the residual component, causing its envelope amplitude to decrease monotonically over time. The decay rate is estimated based on the ratio of the equivalent reactance to the resistance of the primary circuit of the circuit breaker and the voltage phase and current phase difference at the fault initiation time, so as to ensure that the residual component reflects the transient DC characteristics under the relationship between the line equivalent parameters and the fault initiation phase.

[0161] When the monotonic decay constraint is satisfied, and the instantaneous frequencies of the remaining intrinsic mode functions are all located at high frequencies outside the power frequency tracking bandwidth, the set of intrinsic mode functions and the residual components are output. The output residual components are used as transient DC components in subsequent steps.

[0162] For example, in step S101, the device obtains the current and voltage sampling sequence and uses the first power frequency zero crossover of the voltage sequence as the starting point of the analysis window; it cuts the current segment according to a preset length and performs phase-locked mirror extension at the beginning and end of the segment to form a current analysis sequence.

[0163] The device performs empirical mode decomposition on the current analysis sequence: first, it performs screening iterations, constructs upper and lower envelopes based on local extrema, calculates the envelope mean, and outputs the first intrinsic mode function; the above process is repeated to obtain several intrinsic mode functions. During this process, the device continuously monitors the energy change within the power frequency tracking bandwidth, and uses the change being below a threshold as the iteration stopping condition for each intrinsic mode function.

[0164] For the remaining sequence, the device applies a monotonically decaying constraint: it checks whether the envelope amplitude decreases monotonically with time, and estimates and corrects the decay rate by combining the ratio of the equivalent reactance to the resistance of the primary circuit of the circuit breaker and the fault initiation phase difference. When the monotonically decaying constraint is satisfied, and the instantaneous frequencies of the output intrinsic mode functions are all located at high frequencies outside the power frequency tracking bandwidth, the device uses the current result as the output of this decomposition, obtaining the set of intrinsic mode functions and the residual components.

[0165] In this embodiment, the output residual component exhibits an envelope characteristic that decreases over time and does not include oscillation components within the power frequency tracking bandwidth; the output intrinsic mode function covers high-frequency disturbances and higher-order harmonics. Subsequently, the device identifies the residual component as a transient DC component according to the procedure of step S102, and performs subsequent feature extraction based on the sequence after deducting this component.

[0166] For example, after obtaining the voltage and current sampling sequences in step S101, the device takes the first power frequency zero crossover detected in the voltage sequence as the starting point, extracts a current segment covering the fault initiation area and containing at least one power frequency cycle, and performs phase-locked mirror extension on the beginning and end of the segment to obtain the current analysis sequence; then, it constructs upper and lower envelopes based on local extrema on the analysis sequence and calculates the envelope mean, and starts the screening iteration: when the energy change within the power frequency tracking bandwidth is no longer significant, it outputs the first intrinsic mode function IMF1 (which in the time domain is a high-frequency sudden oscillation at the moment of fault initiation, often related to mechanical impact and arc initiation); it continues screening with the remaining sequence to obtain the second intrinsic mode function IMF2 (whose spectral energy is concentrated on the high-frequency side outside the fundamental wave, often manifested as sideband fluctuations near odd harmonics).

[0167] It is understandable that, if necessary, the intrinsic mode function IMF3 (a high-frequency ripple component with low amplitude and short duration) can be further obtained. In the above screening process, a monotonically decaying constraint is applied to the remaining sequence, and its decay pattern is corrected according to the equivalent parameters of the primary loop and the fault initiation phase relationship, until the envelope of the remaining sequence decreases monotonically with time and does not contain the oscillation component within the power frequency tracking bandwidth. The remaining sequence is then output as the residual component. Finally, the result of the IMF set (IMF1, IMF2, IMF3) + residual component is formed, where the instantaneous frequency of each IMF is located on the high-frequency side outside the power frequency tracking bandwidth. The residual component is used to identify the transient DC component in step S102 and deduct it from the original current segment to obtain the pure AC fault current.

[0168] Furthermore, in the initial stage of a fault, the current sequence simultaneously contains mechanical coupling interference introduced by the actuator's operation and transient DC components determined by the network's equivalent parameters. If these are not distinguished during Empirical Mode Decomposition (EMD), the non-stationary components caused by mechanical coupling may enter the residual components, leading to subsequent errors in the identification of transient DC. Therefore, it is necessary to introduce a suppression mechanism related to the circuit breaker's state variables during the screening iteration stage, and to provide a clear output of the transient DC polarity and confidence level after the decomposition is completed.

[0169] Optionally, performing empirical mode decomposition on the acquired current values ​​includes:

[0170] A mechanical interference mask sequence is generated based on the contact open / close position signal and coil drive timing in the circuit breaker state variables.

[0171] During the screening iteration process, weighted suppression is applied to the local extreme points of the upper and lower envelopes according to the mechanical interference mask sequence to reduce the mechanical coupling components from entering the residual components.

[0172] A DC polarity reference is established based on the voltage phase and current polarity at the fault initiation time, and a DC polarity identifier is generated.

[0173] After screening, a DC reliability index is generated based on the energy ratio of the residual component within the power frequency tracking bandwidth and the overlap ratio of the mechanical interference mask.

[0174] The DC polarity identifier and DC confidence index are output along with the intrinsic mode function set and residual components for feature extraction and short-circuit fault identification.

[0175] Among them, the mechanical interference mask sequence is a time sequence generated based on the contact opening and closing position signal and the coil driving timing, which is used to mark the time interval where mechanical coupling interference may exist and its suppression level.

[0176] Weight suppression refers to applying a reduced participation treatment to the local extreme points of the upper and lower envelopes within the mask interval during EMD sieving iteration, in order to reduce the influence of the features of this interval on the intrinsic mode function and residual components.

[0177] The DC polarity identifier is determined based on the voltage phase and current polarity at the fault initiation time, and is used to characterize the polarity direction of the transient DC component.

[0178] The DC confidence index is an index derived from the energy proportion of the residual component within the power frequency tracking bandwidth and the overlap ratio of the mask interval. It is used to characterize the confidence level of the residual component being identified as a transient DC component.

[0179] In practical implementation, the action triggering time is determined from the coil drive timing, and the stable positioning time is determined from the contact opening / closing position signal, forming a time interval from the start of the action to stable positioning. A mask sequence is generated within this interval using a sampling interval consistent with the current analysis sequence, and a suppression level is assigned to the mask according to the action stage. The time base of the mask sequence is consistent with the current analysis sequence used by EMD.

[0180] In each round of EMD screening, upper and lower envelopes are constructed based on local extrema, and the mean of the envelopes is calculated. For local extrema within the mask interval, weighted suppression is applied: in higher suppression levels, the influence of extrema on envelope construction is weakened; in lower suppression levels, only their influence is reduced. This reduces the interference of mechanical coupling on candidate intrinsic components and residual components.

[0181] The fault initiation time is determined by the phase reference point and its neighborhood changes; the voltage phase and current polarity at this time are read to generate a DC polarity identifier. After screening, the energy proportion of the residual component within the power frequency tracking bandwidth is calculated, and the overlap ratio between the high amplitude range of the residual component and the mask range is calculated; these two are combined to form a DC reliability index. The DC polarity identifier and DC reliability index are output and provided to subsequent steps along with the intrinsic mode function set and the residual component.

[0182] For example, the device obtains three types of moments: the rising edge of the coil drive, the first flip of the contact opening / closing position, and the final stable positioning. The period from the rising edge of the coil drive to the stable positioning constitutes a mask time interval; within this interval, the device marks the sub-intervals close to contact collision as having a higher suppression level, the sub-intervals close to electromagnetic acceleration and contact bounce as having a lower suppression level, and the sub-intervals outside the interval as having zero suppression.

[0183] Subsequently, EMD sieving was performed on the current analysis sequence: during the envelope construction stage, extreme points with higher suppression levels had their participation reduced, extreme points with lower suppression levels had their participation weakened, and the remaining extreme points participated normally. After several rounds of sieving, the IMF set was output, and the residual components were obtained.

[0184] The device uses the phase reference point of the voltage sequence to locate the fault initiation time, reads the voltage phase and current polarity at that moment, and generates a DC polarity identifier. Energy domain statistics are performed on the residual components to obtain the energy proportion within the power frequency tracking bandwidth; simultaneously, the high-amplitude range of the residual components is marked, and time overlap calculation is performed with the mask range to obtain the overlap ratio. The energy proportion and overlap ratio are combined into a DC reliability index, which is output along with the DC polarity identifier.

[0185] In this way, by introducing a mask associated with the circuit breaker state variables and weight suppression in the screening stage, the residual components in the EMD results better conform to the morphological requirements of transient DC, and provide additional information that can be directly called by subsequent steps in the form of DC polarity and confidence.

[0186] Furthermore, when a short-circuit fault occurs and triggers current limiting, coil energization, core movement, and contact collisions and bounces introduce non-stationary components coupled with the mechanical process into the current sequence. If these components are not distinguished during Empirical Mode Decomposition (EMD), they may be included in the residual components, interfering with the subsequent identification of transient DC components. Therefore, it is necessary to construct a mechanical interference mask sequence based on the circuit breaker state variables and apply weighted suppression to local extrema within the mask interval during the screening iteration.

[0187] Optionally, the generation of the mechanical interference mask sequence based on the contact open / close position signal and coil drive timing in the circuit breaker state variables includes:

[0188] The closing or opening trigger time is determined from the coil drive timing, and the stable positioning time is determined from the contact opening / closing position signal, thus establishing the time interval from the start of the action to the stable positioning.

[0189] The time interval is divided into an electromagnetic acceleration segment, a contact collision segment, and a contact bounce segment. The first flip of the contact opening / closing position signal is defined as the starting point of the contact collision segment, and the last flip is defined as the ending point of the contact bounce segment.

[0190] A mask sequence is generated within the time interval with a sampling interval consistent with the current analysis sequence. The first suppression level is marked in the electromagnetic acceleration segment and the contact bounce segment, the second suppression level is marked in the contact collision segment, and zero suppression is marked outside the time interval.

[0191] The output mechanical interference mask sequence and segment boundary index are used to apply weighted suppression to local extrema of the upper and lower envelopes during the sieving iteration.

[0192] Among them, the coil drive timing indicator indicates the timing sequence of when the closing or opening coil is driven, which is used to determine the start of the action.

[0193] The contact open / close position signal is a discrete quantity from auxiliary contacts or position sensors; a flip indicates a change in the position state of the contact.

[0194] The stable positioning moment refers to the moment when the contact opening / closing position signal reaches the target state and no longer flips within a predetermined time, which is used to determine the end point of the action.

[0195] The segment boundary index corresponds to the sampling point index on the analysis sequence at the start and end times of each stage, and is used to quickly locate the mask interval during screening.

[0196] In practical implementation, the closing trigger time or opening trigger time is determined from the coil driving timing as the start of the action; the stable positioning time is determined from the contact opening / closing position signal as the end of the action, thus establishing the time interval from the start of the action to the stable positioning.

[0197] Within the aforementioned time interval, the system is divided into three segments: the electromagnetic acceleration segment, the contact collision segment, and the contact bounce segment. The first flip of the contact opening / closing position signal is defined as the starting point of the contact collision segment; the last flip of the contact opening / closing position signal is defined as the ending point of the contact bounce segment. The starting point of the contact bounce segment can be determined by the first reverse flip after the first flip, thus achieving boundary separation from the collision segment.

[0198] A mask sequence is generated within the time interval with a sampling interval consistent with the current analysis sequence; the first suppression level is marked in the electromagnetic acceleration segment and the contact bounce segment, the second suppression level is marked in the contact collision segment, and zero suppression is marked outside the time interval; at the same time, the segment boundary index is output.

[0199] During the upper and lower envelope construction process in each round of EMD screening, weighted suppression is applied to local extreme points within the mask interval based on the mask sequence and segment boundary index: extreme points in the second suppression level interval have their participation in the envelope reduced; extreme points in the first suppression level interval are given a lower level of suppression; and the zero suppression interval is left unprocessed. This reduces the probability of mechanically coupled components entering the residual components.

[0200] For example, in a single closing scenario, the device obtains: the rising edge time of the coil drive t0, the first flip time of the contact open / close position signal t1, followed by several reverse flips (t2, t3…), and finally the stable positioning time t4. The device establishes the time interval [t0, t4] and segments it as follows:

[0201] Electromagnetic acceleration segment: [t0, t1);

[0202] Contact collision segment: [t1, t2) (starting from the first flip and ending at the first reverse flip);

[0203] Contact bounce segment: [t2, t_last] (starting from the first reverse flip and ending at the last flip t_last).

[0204] Subsequently, the device generates a mask sequence M[k] according to the sampling interval consistent with the current analysis sequence. In the electromagnetic acceleration segment and the contact bounce segment, M[k] is set to the first suppression level, and in the contact collision segment, M[k] is set to the second suppression level. Outside the interval, M[k] is set to zero. The device also outputs the segment boundary indexes {k0, k1, k2, k_last, k4}, which correspond to the sampling points of times {t0, t1, t2, t_last, t4} in the analysis sequence.

[0205] During the EMD screening iteration, the device adjusts the participation of extreme points in the upper and lower envelopes according to the aforementioned mask and boundary index: extreme points located in the second suppression level interval (contact collision segment) are significantly weakened, extreme points located in the first suppression level interval (electromagnetic acceleration segment and contact bounce segment) are moderately weakened, and extreme points outside the intervals participate normally. After screening is completed, the mechanical interference mask sequence and segment boundary index are output, which are used to provide subsequent steps along with the intrinsic mode function set and residual components.

[0206] Furthermore, after obtaining the fault type and fault location identifiers, it is necessary to construct a control time reference that is aligned with the grid phase, combining the field voltage phase and the actual action delay of the actuator, so that the current limiting action is implemented within the desired phase range. Simultaneously, a set of parameters that can be directly invoked by the execution layer under a unified time reference needs to be provided, including time grid points, impedance levels, and trigger windows, to support phased current limiting control.

[0207] Optionally, the set of current limiting control parameters includes:

[0208] Calculate the predicted time of the next power frequency zero crossover based on the voltage values ​​in the first set of operating parameters;

[0209] Based on the circuit breaker status variables in the first set of operating parameters, determine the action delay parameters of the current limiting actuator;

[0210] A zero-crossing aligned control time grid is constructed using the predicted time and the action delay parameter;

[0211] On the control time grid, the switching time and tripping trigger window of the controllable impedance stage are determined according to the peak value and short-time root mean square value of the current value in the first set of operating parameters.

[0212] The output consists of a set of current limiting control parameters, which are composed of a time grid vector, an impedance level identifier vector, and a trigger window threshold.

[0213] Among them, the zero-crossing prediction time refers to the time position estimation result of the next voltage zero crossing time after power frequency phase tracking based on the voltage values ​​in the first set of operating parameters.

[0214] The action delay parameter refers to the action delay characteristics of the actuator determined based on the circuit breaker state quantities in the first set of operating parameters, including at least the critical delay amount from the control command to the execution effect.

[0215] The control time grid refers to a discrete time series established with zero-cross prediction time and action delay parameters as anchor points, used to calibrate stage switching and trigger windows.

[0216] The time grid vector refers to the ordered set of sampling point indices that constitute the control time grid.

[0217] Impedance level identifier vectors are vectors that correspond one-to-one with time grid points, used to indicate the controllable impedance level required for each grid point at a given stage.

[0218] The trigger window threshold refers to the boundary description of the allowed interval of action defined on the control time grid, used to constrain the time range of trigger instructions.

[0219] In practice, the voltage sampling sequence is read from the first set of operating parameters, phase tracking is performed, and the next zero-crossing prediction time is extrapolated. This prediction time serves as the phase anchor point of the control time grid. State variables related to the actuator are read from the first set of operating parameters to determine the action delay parameter. This delay is used to align the control time grid, ensuring the execution activation time matches the desired phase interval. Starting from the zero-crossing prediction time, and combining the action delay parameter, several time grid points are generated forward and backward at fixed sampling intervals, covering the control intervals of initial suppression, transition stabilization, and recovery exit. The time grid point vector is recorded as an ordered index sequence. The current value in the first set of operating parameters is read, and combined with the peak value and short-time root mean square within the segment, the switching time of the controllable impedance level is determined on the control time grid according to preset level switching and triggering criteria. Trigger window boundaries are set around key grid points, forming an impedance level identification vector and a trigger window threshold.

[0220] In this way, the time grid vector, impedance level identifier vector and trigger window threshold are combined to form a set of current limiting control parameters, which are then used by the execution layer to implement actions in stages.

[0221] For example, the device reads the voltage sampling sequence from the first set of operating parameters to obtain the next zero-crossing prediction time, and reads the state quantities related to the actuator from the same set to determine the action delay parameters. Using this prediction time as an anchor, the device generates time grids at equal intervals forward and backward within a power frequency cycle after considering the action delay, obtaining a time grid vector; simultaneously, it reads the current sampling sequence of the same segment, calculates the peak value and short-time root mean square within the segment, and marks a higher controllable impedance level on the early grid points, a medium level on the middle grid points, and an exit or lower level on the late grid points according to preset criteria, obtaining an impedance level identification vector.

[0222] Subsequently, the device sets trigger windows around key grid points adjacent to the stage boundary. Each window is described by a start index and an end index, and the window position expands outwards based on the zero-crossing prediction time and action delay to define the allowable range of the trigger command. Finally, the device outputs the time grid point vector - impedance level identifier vector - trigger window threshold as the current limiting control parameter set for one control cycle, which is then translated into execution commands and used by subsequent steps to complete the current limiting action.

[0223] Furthermore, current limiting control must be consistent with the grid phase and the actual response of the actuator. If the estimation of the actuator's action delay is inaccurate, the current limiting trigger will deviate from the target phase range, affecting the current limiting effect and selective coordination. Therefore, under a unified time reference, based on the observable characteristics of the coil drive and contact position signals and the coil current waveform, it is necessary to decompose the electromagnetic release delay, gap establishment delay, and stable positioning delay, and combine them with the control power supply voltage and ambient temperature for temperature and pressure correction, outputting action delay parameters for control time grid alignment.

[0224] Optionally, the determination of the action delay parameters of the current limiting actuator includes:

[0225] The trigger time of the action is determined based on the coil drive timing, and the coil current waveform and contact opening / closing position signal are obtained under the same time reference.

[0226] The slope change and back EMF dip characteristics of the coil current waveform are detected to locate the release feature point and obtain the electromagnetic release delay.

[0227] The time difference between the first stable flip of the contact opening / closing position signal and the release feature point is used as the opening distance establishment delay;

[0228] The time difference between the last flip of the contact open / close position signal and the stable position is taken as the stable position delay;

[0229] Based on the state variables of the control power supply voltage and ambient temperature, the electromagnetic release delay, the opening gap establishment delay, and the stable positioning delay are corrected by temperature and pressure, and the action delay parameter composed of the electromagnetic release delay, the opening gap establishment delay, and the stable positioning delay is output.

[0230] The action triggering time refers to the arrival time of the effective edge used to excite the coil in the coil driving timing.

[0231] The release feature point refers to the characteristic position in the coil current waveform corresponding to the destruction of the electromagnetic holding force or the sudden change in the magnetic circuit state, which is located under the joint indication of the change in the coil current slope and the back electromotive force dip.

[0232] The first stable flip point refers to the moment when the contact opening / closing position signal does not reverse within a predetermined duration after its first flip, and is used to mark the node where the opening distance is established.

[0233] The last flip time refers to the last flip time of the contact opening / closing position signal during the operation process. It is used together with the stable positioning criterion to identify the node before the contact bounce ends.

[0234] In practical implementation, the device acquires the coil drive timing under the same time reference as the current and voltage sampling. The arrival time of the effective drive edge is taken as the action trigger time, and the coil current waveform and contact opening / closing position signal are acquired simultaneously. After smoothing, the coil current waveform undergoes slope change detection, and the back electromotive force dip feature corresponding to the abrupt change in magnetic circuit state is retrieved. When the slope change and the dip feature coincide or are adjacent in time, the position is determined as the release feature point, and the time difference from the action trigger time to the release feature point is defined as the electromagnetic release delay.

[0235] Subsequently, the moment of the first stable flip is located in the contact opening and closing position signal, and the time difference between it and the release feature point is defined as the opening gap establishment delay; the moment of the last flip and the moment of stable positioning are further identified, and the time difference between the moment of stable positioning and the moment of the last flip is defined as the stable positioning delay.

[0236] The device reads the status variables of the control power supply voltage and ambient temperature, and performs temperature and pressure corrections on the above three delays according to the working condition compensation relationship obtained by the device calibration, forming action delay parameters applicable to the current working condition; the corrected electromagnetic release delay, opening gap establishment delay and stable positioning delay are output in a fixed field order for control time grid alignment and subsequent current limiting control.

[0237] For example, during a single closing process, the device records the rising edge of the coil drive as the trigger moment and acquires the coil current and contact open / close position signals at the same time reference. After triggering, the coil current experiences a sudden change in slope followed by a short-term drop in a concave range. Based on this, the device determines the release characteristic point and obtains the electromagnetic release delay. The contact open / close position signal then flips and stabilizes for the first time after a brief fluctuation. The device compares the moment of the first stable flip with the release characteristic point to obtain the gap establishment delay. During the subsequent bounce, the contact experiences a final flip and finally stabilizes in place. The device uses the difference between the stable placement moment and the final flip moment to obtain the stable placement delay.

[0238] After reading the control power supply voltage and ambient temperature for the current action, the device performs temperature and pressure corrections on the three time delays respectively, and constructs the action time delay parameters in a fixed order of "electromagnetic release time delay, gap establishment time delay, and stable positioning time delay", which are then provided for subsequent steps to call.

[0239] Furthermore, after the current-limiting action is completed, its effectiveness needs to be objectively evaluated under a unified time reference. The evaluation results should simultaneously reflect the current load level, spectral composition, and transient DC residual status, and be provided to the parameter update process in the form of structured data. If the completion time is inaccurate, the evaluation window is not synchronized with the power frequency, or the source of the indicators is not transparent, the status feedback data will be unstable, thereby affecting the reliability of subsequent updates to the current-limiting control parameters.

[0240] Optionally, the step of performing flow limiting effect analysis based on the second set of operating parameters and generating status feedback data includes:

[0241] The completion time of the current limiting action is determined based on the circuit breaker status variables in the second set of operating parameters, and an evaluation window is established in the adjacent power frequency cycle after that time.

[0242] Within the evaluation window, the peak value, short-time root mean square value, and current square time integral value of the current values ​​in the second set of operating parameters are calculated to generate a set of electrical load parameters.

[0243] The power frequency tracking result is obtained based on the voltage value in the second set of operating parameters. The amplitude ratio of the fundamental component to the odd harmonic component is calculated within the evaluation window, and the remaining proportion of the transient DC component is estimated. The amplitude ratio, the remaining proportion, and the set of electrical load parameters are combined into state feedback data.

[0244] Among them, the evaluation window refers to the time interval established within the adjacent power frequency cycle starting from the completion time of the current limiting action; the set of electrical load parameters refers to the peak value, short-time root mean square value, and time integral value of the current square obtained from the current value within the evaluation window; the power frequency tracking result refers to the tracking information of the power frequency phase and frequency over time obtained based on the voltage value; the fundamental component and odd harmonic components refer to the amplitude of the current component at the power frequency and its odd harmonics; the remaining proportion of the transient DC component refers to the proportion of the zero-frequency or near-zero-frequency trend term relative to the overall current magnitude within the evaluation window; and the state feedback data refers to the structured output composed of the odd harmonic amplitude ratio, the remaining proportion of transient DC, and the set of electrical load parameters in a fixed field order.

[0245] In specific implementation, the device first determines the completion time of the current limiting action based on the circuit breaker status: the contact opening and closing position signal reaches the target state and does not flip again in a short period of time as the completion mark, and the coil current changes from dynamic state to steady state as the cross-check; when the two are consistent under the same time reference, the time is taken as the completion time.

[0246] Starting from the completion time, the length of the adjacent power frequency cycle is established as the evaluation window; when there is a slight deviation in the power frequency, the length of a single cycle is determined by the power frequency tracking result obtained based on the voltage value, so as to ensure that the window is synchronized with the power frequency phase.

[0247] Within the aforementioned evaluation window, current values ​​are used to generate a set of electrical load parameters: the peak value is taken as the point with the maximum absolute value of the current within the window; the short-time root mean square value is obtained by equal-weighted averaging within the window; and the current square time integral value is obtained by discretely accumulating the current square sequence within the window. These three values ​​respectively reflect instantaneous electrical stress, effective load level, and energy accumulation characteristics. Subsequently, the current window is synchronously spectrum-positioned based on the power frequency tracking results. The fundamental amplitude is read at an integer period or integer multiple of the period that is in phase with the power frequency, and the corresponding amplitude is read at odd harmonics. The ratio of each odd harmonic amplitude to the fundamental amplitude forms an odd harmonic amplitude ratio vector. To estimate the residual proportion of the transient DC component, the device first performs a power frequency-synchronized decomposition on the current sequence within the same window, subtracting the fundamental and major odd harmonics to obtain the residual sequence. Then, a low-frequency trend term is extracted from the residual sequence, such as a low-pass trend term or an equivalent DC trend term synchronized with the power frequency. The proportion of this trend term relative to the current level within the window is used as a description of the degree of transient DC residue.

[0248] If a voltage phase tracking discontinuity or a brief contact flip is detected at the window boundary, the device marks the window as "needs to be retrieved" to prevent invalid data from entering the feedback.

[0249] The above three types of results are combined into status feedback data in a fixed field order, and are accompanied by the start and end indexes and validity markers of the evaluation window for use in subsequent parameter update processes.

[0250] For example, after a current-limiting action, the device marks completion by indicating that the contact open / closed position signal has reached the open position and no longer flips within a few milliseconds. Simultaneously, it observes the steady-state trend of the coil current changing from rapid to slow change. When both coincide on the same time reference, this moment is taken as the completion time of the current-limiting action. Based on this, the device extracts a segment of current and voltage from the subsequent power frequency cycle and sets this segment as the evaluation window. If the voltage zero-crossing interval changes slightly, the window length is set based on the single-cycle length obtained from voltage phase tracking to maintain consistency with the power frequency phase.

[0251] Within this evaluation window, the device directly obtains the peak value from the current sampling sequence; calculates the short-time root mean square value of the samples within the window in an equal-weighted manner; and accumulates the current square sequence point by point to obtain the current square time integral value. The above three items constitute the set of electrical load parameters.

[0252] Subsequently, the device performs power frequency phase and frequency tracking using the voltage segment, and performs spectral localization of the current segment over an entire cycle synchronized with this phase. It reads the fundamental amplitude and several odd harmonic amplitudes, and constructs an odd harmonic amplitude ratio vector by comparing the ratios of each odd harmonic amplitude to the fundamental amplitude. To estimate the remaining proportion of transient DC, the device decomposes the current segment in power frequency synchronization within the same evaluation window, removing the fundamental wave and major odd harmonics to obtain the remaining sequence. A low-frequency trend term is then extracted from the remaining sequence, and this trend term is normalized and compared with the overall current magnitude within the window to obtain the remaining proportion of the transient DC component.

[0253] If a discontinuity in voltage phase tracking or a flipping contact signal is detected near the start of the window, the window is marked as "needs to be re-established". The device then extends the window by one cycle synchronized with the power frequency and re-establishes the window, repeating the above process.

[0254] Finally, the device combines the "odd harmonic amplitude ratio vector, transient DC residual ratio, and electrical load parameter set" into status feedback data in a fixed field order, and adds the start and end indexes and validity markers of the evaluation window for direct use in the parameter update process.

[0255] Furthermore, after the current limiting action is completed, the set of current limiting control parameters for the next action needs to be updated in a controllable, traceable, and non-oscillating manner based on the status feedback data obtained in step S106. If the update lacks a comparable reference to the target, lacks single-step amplitude and boundary constraints, or lacks dead zone determination, it can easily lead to parameter jitter, over-correction, or long-term deviation.

[0256] Optionally, the updated set of current limiting control parameters includes:

[0257] Calculate the current peak deviation, short-time root mean square deviation, fundamental to odd harmonic amplitude ratio deviation, and transient DC residual ratio deviation from the state feedback data to generate a parameter adjustment vector.

[0258] Based on the parameter adjustment vector, and under the preset single-step amplitude, upper and lower limit constraints, and dead zone determination rules, the time parameter, impedance level parameter, and trigger threshold parameter in the current limiting control parameter set are updated.

[0259] When the deviation of the transient DC residual ratio is higher than the first update threshold, the impedance level of the initial stage is increased and the duration of the initial stage is extended.

[0260] When the deviation between the amplitude ratio of the fundamental wave and the odd harmonics is higher than the second update threshold, the trigger threshold is tightened; when the absolute value of each deviation is lower than the third update threshold, the set of current limiting control parameters remains unchanged.

[0261] Output the updated set of current limiting control parameters.

[0262] The parameter adjustment vector is a vector formed by uniformly encoding the deviations of each evaluation index, serving as the direct input for updates. The time parameter item is related to the control time grid, including descriptions of the grid points where the stage boundaries are located and the stage duration. The impedance level parameter item is a sequence of controllable impedance levels marked on the time grid. The trigger threshold parameter item describes the thresholds and window boundaries used to limit the allowed triggering interval or entry conditions.

[0263] In practical implementation, the device first establishes a reference index set corresponding to the current current limiting control parameter set, which is used to compare the parameters with the status feedback data item by item. The reference index set is derived from the dynamic current limiting control curve and its target envelope description generated in step S104: the target peak value is obtained by reading the upper bound of the target envelope within the evaluation window; the target short-time root mean square is obtained by performing equal-weighted statistics on the target envelope over an integer period or multiple period synchronized with the power frequency; the target fundamental frequency to odd harmonic amplitude ratio is obtained by synchronously spectral positioning and reading the target envelope; the target transient DC residual ratio is obtained by qualitatively estimating the low-frequency trend term of the target envelope within the evaluation window.

[0264] The "actual peak value, actual short-time root mean square, actual odd harmonic amplitude ratio vector, and actual transient DC residual ratio" in the status feedback data are compared with the above targets one by one to obtain the "current peak deviation, short-time root mean square deviation, fundamental frequency to odd harmonic amplitude ratio deviation, and transient DC residual ratio deviation", which are then encoded into parameter adjustment vectors in a fixed field order.

[0265] During updates, the device performs restricted single-step adjustments to the time parameter, impedance level parameter, and trigger threshold parameter based on the parameter adjustment vector. The single-step amplitude is provided by the strategy library to ensure that the change in each update does not exceed the preset step size; the upper and lower limits are given by the device's engineering allowable range, and the value to be updated is truncated at the boundary; dead zone determination is used to keep the value unchanged when the absolute value of the deviation is below the threshold, avoiding minor noise triggering updates.

[0266] To handle potential simultaneous exceedances of various parameters, the device employs a priority rule: when the deviation of the transient residual DC ratio exceeds the first update threshold, the residual DC problem is addressed first by extending the duration of the initial stage in the time parameter and increasing the impedance level of the initial stage in the impedance level parameter; when the deviation of the fundamental to odd harmonic amplitude ratio exceeds the second update threshold, the trigger threshold is tightened first, specifically by narrowing the time boundary of the trigger window and increasing the stringency of the entry conditions; in other cases, small-step corrections are made in the direction of peak value and short-time root mean square deviation. If the absolute values ​​of all deviations are below the third update threshold, the current limiting control parameter set remains unchanged.

[0267] After completing the above-mentioned restricted update, output the updated set of rate limiting control parameters and mark it as the currently effective set of parameters for use in the next running cycle.

[0268] For example, within the evaluation window after a current limiting operation, the device obtains the following from the status feedback data: actual peak value, actual short-time root mean square value, current square time integral value, odd harmonic amplitude ratio vector, and transient DC residual ratio. Simultaneously, the device generates a set of reference indicators based on the dynamic current limiting control curve used in this operation:

[0269] (1) The target peak value is determined based on the maximum value of the target envelope within the evaluation window;

[0270] (2) The short-time root mean square of the target is obtained by performing equal-weighted statistics on the target envelope within an integer period synchronized with the power frequency;

[0271] (3) The target odd harmonic amplitude ratio is obtained by synchronously spectral positioning of the target envelope at the power frequency and odd harmonics;

[0272] (4) The target transient DC remaining percentage is obtained by extracting the low-frequency trend term of the target envelope within the evaluation window and normalizing it with the target total magnitude.

[0273] The device compares the actual values ​​with the target values ​​item by item to obtain the parameter adjustment vector. In this example, the actual peak value is slightly higher, the actual short-time root mean square value is higher than the target, the odd harmonic amplitude ratio is close to the target, and the transient residual DC ratio is significantly higher than the target. According to the priority rule, the device first processes the residual DC deviation: in the time parameter, the duration of the initial stage is extended backward by one step along the control time grid, and in the impedance level parameter, the impedance level of the initial stage is increased by one level; subject to upper and lower limit constraints, if the extension or increase touches the boundary, it is truncated at the boundary. At the same time, to suppress the thermal load deviation, the boundary between the initial stage and the transition stage is fine-tuned without changing the stage sequence, so that the boundary grid point is moved forward by one minimum step. Since the odd harmonic amplitude ratio deviation does not exceed the second update threshold, the trigger threshold parameter remains unchanged. If the odd harmonic amplitude ratio deviation is significantly higher in another scenario, the device prioritizes tightening the trigger threshold: reducing the width of the trigger window around the key grid point and increasing the stringency of the trigger entry conditions; when tightening conflicts with the aforementioned extension, the rule of "safety first, efficiency later" is followed, first implementing the extension and impedance increase of the initial stage, and then tightening the trigger window in the remaining space.

[0274] In the above example, all adjustments follow the single-step amplitude and dead-zone determination: if the absolute value of a certain deviation has fallen into the dead zone corresponding to the third update threshold, then that item is not updated; if two consecutive updates touch the edge in the same direction, the device keeps that item at the boundary value and does not accumulate. After completing this update, the device outputs an updated set of current limiting control parameters containing "time parameter items, impedance level parameter items, and trigger threshold parameter items", which will be used as the effective parameter set for the next operating cycle in the adaptation and generation of step S104.

[0275] In one embodiment, the current limiting actuator may include a power electronic current limiting module, which includes: a power switching device unit, a controllable impedance network unit, a drive and protection unit, and a sampling and isolation unit. The power switching device unit provides rapid turn-on, turn-off, or bypass switching capabilities during the current limiting phase; the controllable impedance network unit forms multiple switchable equivalent impedance levels; the drive and protection unit implements gate / gate drive for the power switching device unit and provides overcurrent, overvoltage, and overtemperature protection; the sampling and isolation unit acquires module voltage, current, and temperature on the high-voltage side and outputs them to the controller side after isolation. The power electronic current limiting module can be integrated with the circuit breaker body as an integrated current limiting component, or it can be mounted as a replaceable pluggable module within the circuit breaker housing.

[0276] In one optional implementation, to ensure that the current limiting control is consistent with the actual response of the actuator, factory testing and calibration of the power electronic current limiting module are required during the manufacturing stage, generating a set of factory calibration parameters for aligning the control time grid during operation. This set of factory calibration parameters can serve as the initial value source for the first set of operating parameters during operation, or as a reference parameter for online updates during operation. In existing solutions, the controller predicts the next zero-crossing moment at the power frequency based on the voltage value and determines the action delay parameters based on the circuit breaker state variables to construct a zero-crossing aligned control time grid. This, in turn, determines the switching moment of the controllable impedance level and the tripping trigger window, and outputs a set of current limiting control parameters consisting of a time grid vector, an impedance level identifier vector, and a trigger window threshold. Therefore, the calibration during the manufacturing stage must at least cover: power switch action delay, impedance level equivalent parameters, and temperature and pressure correction parameters to ensure the alignment accuracy of the aforementioned time grid and trigger window.

[0277] In one embodiment, the manufacturing and factory calibration of the power electronic current limiting module may include the following process. First, module assembly is completed: the power switching device unit and the conductive busbar / conductive substrate form the main current path; the controllable impedance network unit and the power switching device unit are connected according to a preset topology to form a multi-level switchable impedance path; and the drive and protection unit, sampling and isolation unit are fixed on the module housing or substrate. The heat dissipation structure and insulation structure are assembled, and the consistency of key connection points is checked to ensure that the main circuit resistance, insulation withstand voltage, and heat dissipation path meet preset windows. The consistency check may include: measuring the main circuit on-resistance and comparing it with a preset upper limit; testing the withstand voltage and insulation resistance to confirm that the assembly quality requirements are met; and verifying the response consistency of the temperature sampling points.

[0278] Secondly, standardized current-limiting excitation is applied to the power electronic current-limiting module on a test fixture, and response data is collected. The test fixture may include a controllable current source, an equivalent line impedance loop, a phase reference source, and a high-speed sampling unit. The phase reference source is used to generate a reference signal consistent with the power frequency phase, so as to reproduce the "zero cross-alignment" control condition during operation in the factory test. The high-speed sampling unit is used to synchronously collect module voltage, current, power switch gate / gate drive timing, protection trigger indication, and module temperature status under a unified time base, thereby forming a set of factory test operating parameters. To improve calibration coverage, the standardized current-limiting excitation may include excitation combinations with different peak current levels and different phase ranges, and may include multiple repetition cycles to extract statistically stable time delay and equivalent impedance parameters.

[0279] In one optional implementation, the action delay parameters of the power electronic current limiting module are determined based on the set of factory test operating parameters. The action delay parameters may include at least: turn-on setup delay, impedance level setup delay, and turn-off recovery delay. The action trigger time can be defined as the arrival time of the effective edge in the power switch gate / gate drive timing; the turn-on setup delay can be obtained from the time difference between the action trigger time and the rapid drop in module voltage by a preset amplitude or the rise in module current by a preset slope; the impedance level setup delay can be obtained from the time difference between the arrival time of the effective edge of the impedance level switching command and the time difference between the peak value or short-time root mean square of the module current entering the target range; the turn-off recovery delay can be obtained from the time difference between the arrival time of the effective edge of the turn-off command and the time difference between the module voltage recovering to the preset range or the module current decaying to the preset threshold. Furthermore, the above tests can be repeated under different control power supply voltages and different module temperatures, and a temperature and pressure correction model can be constructed to output the action delay parameters for control time grid alignment. Existing solutions use a "unified time reference + feature point detection + temperature and pressure correction" approach to ensure phase alignment for the action delay parameters of mechanical actuators. The operating delay parameters of the aforementioned power electronic current limiting module can adopt the same correction framework for unified invocation at the system level.

[0280] In one embodiment, the equivalent parameters of the controllable impedance level are further determined based on the set of factory test operating parameters, and a calibration mapping of the impedance level identification vector is generated. Specifically, for each impedance level, the equivalent impedance value, allowable duration, unit energy loss coefficient, and / or temperature rise time constant corresponding to that impedance level are calculated within a preset evaluation window, and a mapping relationship is established between them and the impedance level number. The equivalent impedance value can be estimated from the ratio of module voltage to module current within a steady-state window; the allowable duration can be jointly determined by the upper limit of temperature rise and energy integral constraint; and the unit energy loss coefficient can be obtained by fitting the current squared time integral value with the temperature rise. The mapping relationship can serve as the constraint basis for determining the "controllable impedance level switching time and trigger window threshold" during operation, enabling the controller to simultaneously satisfy phase alignment and thermal safety constraints when outputting the current-limiting control parameter set consisting of the time grid vector, impedance level identification vector, and trigger window threshold.

[0281] In an optional implementation, the factory calibration parameter set may further include grading information for manufacturing consistency management and assembly matching. Specifically, power electronic current limiting modules can be graded based on turn-on delay, impedance level turn-on delay, equivalent impedance error, and thermal characteristic parameters. Modules meeting a preset window are assigned a first-grade label, modules meeting a more lenient window are assigned a second-grade label, and modules exceeding the window are deemed unqualified and discarded or reworked. Different grades may correspond to different initial values ​​of the default current limiting control parameter set or different trigger window threshold safety margins to reduce the impact of batch dispersion on current limiting effect and selective matching.

[0282] In one embodiment, the factory-calibrated parameter set is written to the storage unit of the power electronic current-limiting module or to the parameter storage area associated with the circuit breaker controller for direct reading and retrieval during operation. The written content may include: action delay parameters and their temperature and pressure correction coefficients, equivalent parameters and allowable durations for each impedance level, level identifiers, and version verification information. During operation, when a short-circuit fault occurs and the current-limiting phase begins, the controller constructs a zero-crossing aligned control time grid based on the factory-calibrated parameter set. It then determines the switching time and tripping trigger window for the controllable impedance level on the control time grid and outputs the current-limiting control parameter set. Furthermore, during operation, status feedback data can be generated based on indicators such as the peak current, short-time root mean square, and current square time integral after the current-limiting action. This data is used to correct or update the factory-calibrated parameter set online, thereby adapting to differences in field operating conditions without changing the manufacturing calibration benchmark.

[0283] Based on the same inventive concept, this application also provides an adaptive short-circuit fault current limiting control system for a primary and secondary integrated circuit breaker, corresponding to the adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker. Since the principle of the system in this application is similar to the adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker described above, the implementation of the system can refer to the implementation of the method, and the repeated parts will not be described again.

[0284] See Figure 4 This is a schematic diagram of an adaptive short-circuit fault current limiting control system for a primary and secondary integrated circuit breaker provided in an embodiment of this application. The system includes:

[0285] The acquisition module 10 is used to acquire the current value, voltage value and circuit breaker status of the power distribution line to obtain the first set of operating parameters;

[0286] The first processing module 20 performs feature extraction operations on the amplitude abrupt change, phase offset and harmonic components of the current waveform based on the first set of operating parameters to generate a first feature vector; it matches the first feature vector with a preset short-circuit fault feature template to determine the short-circuit fault identification result and generates a fault type identifier and a fault location identifier.

[0287] The second processing module 30 calculates a dynamic current limiting control curve for the fault type and the fault location based on the fault type identifier, the fault location identifier, and the current value in the first set of operating parameters, and generates a set of current limiting control parameters.

[0288] Control module 40 is used to control the current limiting actuator of the circuit breaker to perform current limiting according to the current limiting control parameter set and generate current limiting response data;

[0289] The feedback module 50 is used to collect the status values ​​of the circuit breaker and the current values ​​of the line after the current limiting action is completed, and generate a second set of operating parameters; perform current limiting effect analysis based on the second set of operating parameters, and generate status feedback data; and update the current limiting control parameter set based on the status feedback data.

[0290] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker, characterized in that, include: Collect the current and voltage values ​​of the power distribution lines and the status parameters of the circuit breakers to obtain the first set of operating parameters; Based on the first set of operating parameters, feature extraction operations are performed on the amplitude abrupt change, phase offset, and harmonic components of the current waveform to generate the first feature vector; Based on the first feature vector, a preset short-circuit fault feature template is matched to determine the short-circuit fault identification result, and a fault type identifier and a fault location identifier are generated. Based on the fault type identifier, fault location identifier, and current value in the first set of operating parameters, calculate the dynamic current limiting control curve for the fault type and fault location, and generate the current limiting control parameter set. The generation of the current limiting control parameter set includes: calculating the predicted time of the next power frequency zero crossover based on the voltage value in the first operating parameter set; determining the action delay parameter of the current limiting actuator based on the circuit breaker status quantity in the first operating parameter set; constructing a zero-crossover aligned control time grid with the predicted time and the action delay parameter; and determining the switching time and tripping trigger window of the controllable impedance stage on the control time grid according to the peak value and short-time root mean square value of the current value in the first operating parameter set. The output consists of a set of current limiting control parameters, which are composed of a time grid vector, an impedance level identifier vector, and a trigger window threshold. Based on the set of current limiting control parameters, the current limiting actuator of the circuit breaker is controlled to perform current limiting and generate current limiting response data. After the current limiting action is completed, the status variables of the circuit breaker and the current value of the line are collected to generate a second set of operating parameters; Analyze the effect of current limiting based on the second set of operating parameters, generate status feedback data, and update the set of current limiting control parameters based on the status feedback data. The generation of state feedback data includes: determining the completion time of the current limiting action based on the circuit breaker state quantities in the second set of operating parameters, and establishing an evaluation window in the adjacent power frequency cycle after that time; calculating the peak value, short-time root mean square value and current square time integral value of the current values ​​in the second set of operating parameters within the evaluation window to generate a set of electrical load parameters. The power frequency tracking result is obtained based on the voltage value in the second set of operating parameters. The amplitude ratio of the fundamental component to the odd harmonic component is calculated within the evaluation window, and the remaining proportion of the transient DC component is estimated. The amplitude ratio, the remaining proportion, and the set of electrical load parameters are combined into state feedback data.

2. The adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker according to claim 1, characterized in that, The generation of the first feature vector includes: Empirical mode decomposition is performed on the collected current values, which are decomposed into multiple intrinsic mode functions and a residual component; The residual component was identified as the transient DC component in the short-circuit current; Subtract the transient DC component from the collected current value to obtain the pure AC fault current. Based on the pure AC fault current, feature extraction operations are performed on amplitude, phase, and harmonics to generate the first feature vector.

3. The adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker according to claim 2, characterized in that, The empirical mode decomposition (EMD) of the acquired current values, which decomposes them into multiple intrinsic mode functions and a residual component, includes: A phase-aligned analysis window is constructed starting from the first power frequency zero-crossing determined based on the voltage value, and a phase-locked mirror extension is performed on both ends of the analysis window to obtain the current analysis sequence. Based on the current analysis sequence, upper and lower envelopes are constructed according to local extreme points and the mean value of the envelope is calculated to perform screening iteration. The iteration stopping condition of the screening is set to the energy change within the power frequency tracking bandwidth being lower than a preset first threshold. During the screening process, a monotonically decaying constraint is applied to the residual component. The decay rate is calculated based on the ratio of the equivalent reactance to the resistance of the primary circuit of the circuit breaker and the phase difference between the voltage phase and the current phase. When the monotonic decay constraint is satisfied and the instantaneous frequency of each intrinsic mode function falls on the high-frequency side outside the power frequency tracking bandwidth, the set of intrinsic mode functions and residual components are output.

4. The adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker according to claim 3, characterized in that, The empirical mode decomposition of the acquired current values ​​includes: A mechanical interference mask sequence is generated based on the contact open / close position signal and coil drive timing in the circuit breaker state variables. During the screening iteration process, weighted suppression is applied to the local extreme points of the upper and lower envelopes according to the mechanical interference mask sequence to reduce the mechanical coupling components from entering the residual components. A DC polarity reference is established based on the voltage phase and current polarity at the fault initiation time, and a DC polarity identifier is generated. After screening, a DC reliability index is generated based on the energy ratio of the residual component within the power frequency tracking bandwidth and the overlap ratio of the mechanical interference mask sequence. The DC polarity identifier and DC confidence index are output along with the intrinsic mode function set and residual components for feature extraction and short-circuit fault identification.

5. The adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker according to claim 4, characterized in that, The mechanical interference mask sequence generated based on the contact open / close position signal and coil drive timing in the circuit breaker state variables includes: The closing or opening trigger time is determined from the coil drive timing, and the stable positioning time is determined from the contact opening / closing position signal, thus establishing the time interval from the start of the action to the stable positioning. The time interval is divided into an electromagnetic acceleration segment, a contact collision segment, and a contact bounce segment. The first flip of the contact opening / closing position signal is defined as the starting point of the contact collision segment, and the last flip is defined as the ending point of the contact bounce segment. A mask sequence is generated within the time interval with a sampling interval consistent with the current analysis sequence. The first suppression level is marked in the electromagnetic acceleration segment and the contact bounce segment, the second suppression level is marked in the contact collision segment, and zero suppression is marked outside the time interval. The output mechanical interference mask sequence and segment boundary index are used to apply weighted suppression to local extrema of the upper and lower envelopes during the sieving iteration.

6. The adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker according to claim 1, characterized in that, The determination of the action delay parameters of the current limiting actuator includes: The trigger time of the action is determined based on the coil drive timing, and the coil current waveform and contact opening / closing position signal are obtained under the same time reference. The slope change and back EMF dip characteristics of the coil current waveform are detected to locate the release feature point and obtain the electromagnetic release delay. The time difference between the first stable flip of the contact opening / closing position signal and the release feature point is used as the opening distance establishment delay; The time difference between the last flip of the contact open / close position signal and the stable position is taken as the stable position delay; Based on the state variables of control power supply voltage and ambient temperature, temperature and pressure corrections are applied to the electromagnetic release delay, the gap establishment delay, and the stable positioning delay, and the action delay parameter composed of the electromagnetic release delay, the gap establishment delay, and the stable positioning delay is output.

7. The adaptive short-circuit fault current limiting control method for a primary and secondary integrated circuit breaker according to claim 1, characterized in that, Also includes: Manufacturing and factory calibration are performed on the power electronic current limiting module that is the current limiting actuator or constitutes part of the current limiting actuator, the manufacturing and factory calibration including: The power switching device unit, the controllable impedance network unit, and the drive and protection unit are assembled and electrically connected to form the power electronic current limiting module; A standardized current limiting excitation is applied to the power electronic current limiting module on the test fixture, and the module voltage, module current, drive timing and module temperature status are collected simultaneously to obtain the set of factory test operation parameters. Based on the set of factory test operation parameters, the action delay parameters of the power electronic current limiting module are determined, and the equivalent parameters of each impedance level of the controllable impedance network unit are determined. Based on the action delay parameters and the equivalent parameters of each impedance level, a set of factory calibration parameters is generated, and the set of factory calibration parameters is written into the storage unit of the power electronic current limiting module and / or the parameter storage area of ​​the circuit breaker controller. The set of factory calibration parameters is used to construct a zero-crossing aligned control time grid and determine the switching time and tripping trigger window of the controllable impedance level when the current limiting control parameter set is generated.

8. An adaptive short-circuit fault current limiting control system for a primary and secondary integrated circuit breaker, characterized in that, include: The data acquisition module is used to collect the current value, voltage value and circuit breaker status of the power distribution line to obtain the first set of operating parameters; The first processing module, based on the first set of operating parameters, performs feature extraction operations on the amplitude abrupt changes, phase shifts, and harmonic components of the current waveform to generate a first feature vector; according to The first feature vector is matched with the preset short-circuit fault feature template to determine the short-circuit fault identification result and generate the fault type identifier and fault location identifier. The second processing module calculates a dynamic current limiting control curve for the fault type and the fault location based on the fault type identifier, the fault location identifier, and the current value in the first set of operating parameters, and generates a set of current limiting control parameters. The generation of the current limiting control parameter set includes: calculating the predicted time of the next power frequency zero crossover based on the voltage value in the first operating parameter set; determining the action delay parameter of the current limiting actuator based on the circuit breaker status quantity in the first operating parameter set; constructing a zero-crossover aligned control time grid with the predicted time and the action delay parameter; determining the switching time and tripping trigger window of the controllable impedance level on the control time grid according to the peak value and short-time root mean square value of the current value in the first operating parameter set; and outputting the current limiting control parameter set composed of a time grid vector, an impedance level identifier vector, and a trigger window threshold. The control module is used to control the current limiting actuator of the circuit breaker to perform current limiting based on the set of current limiting control parameters, and to generate current limiting response data. The feedback module is used to collect the status variables of the circuit breaker and the current value of the line after the current limiting action is completed, and generate a second set of operating parameters; perform current limiting effect analysis based on the second set of operating parameters, and generate status feedback data; and update the current limiting control parameter set based on the status feedback data. The analysis of the rate limiting effect based on the second set of operating parameters, and the generation of status feedback data, include: The completion time of the current limiting action is determined based on the circuit breaker status variables in the second set of operating parameters, and an evaluation window is established in the adjacent power frequency cycle after that time. Within the evaluation window, the peak value, short-time root mean square value, and current square time integral value of the current values ​​in the second set of operating parameters are calculated to generate a set of electrical load parameters. Based on the voltage values ​​in the second set of operating parameters, the power frequency tracking result is obtained. Within the evaluation window, the amplitude ratio of the fundamental component to the odd harmonic component is calculated and the remaining proportion of the transient DC component is estimated. The amplitude ratio, the remaining proportion, and the set of electrical load parameters are combined to form state feedback data.

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