A DC Port Short-Circuit Current Protection Method for a Power Electronic Transformer

Abstract

The present invention discloses a method for protecting the short-circuit current of the DC port of a power electronic transformer, which relates to the field of power control technology. The method includes: after detecting an abnormal short-circuit current at the DC port, generating a control instruction to drive an ultrafast electronic switch to perform a cut-off action, and recording and uploading the time, location, and abnormal parameters of the fault occurrence, generating a fault diagnosis result and a maintenance suggestion; when it is confirmed that the recovery condition is met according to the fault diagnosis result and the maintenance suggestion, starting a recovery process to reconnect the power electronic transformer to the DC power supply circuit; continuously and real-time collecting operation status data, combining the operation status data set with the abnormal parameters recorded in the fault diagnosis result, and dynamically correcting the short-circuit current response mechanism by using an adaptive update algorithm. By optimizing the protection mechanism and monitoring and analyzing faults in real time, the present invention reduces the risks and downtime losses caused by equipment failure or external environment changes.

Description

Technical Field

[0001] The present invention relates to the technical field of power control, and particularly to a method for protecting the short-circuit current of the DC port of a power electronic transformer. Background Art

[0002] As a new generation of distribution equipment, the power electronic transformer integrates various technologies such as power electronic conversion, communication, and intelligent control, and has wide applications in scenarios such as new energy access, flexible power distribution, rail transit, and data centers. Compared with traditional power frequency transformers, the power electronic transformer has advantages such as small volume, light weight, diverse functions, and flexible regulation, and has gradually become a key core device in the smart grid. Especially in high-voltage DC power distribution, the DC port of the power electronic transformer directly undertakes the power supply demand of the load side, and its operating state has an important impact on the overall stability and safety. Therefore, in order to ensure good anti-interference and fast protection capabilities in the event of a sudden short circuit, it is urgent to effectively monitor and handle the short-circuit fault of the DC port of the power electronic transformer.

[0003] Most of the existing short-circuit protection methods for power electronic transformers rely on traditional threshold trigger strategies to achieve fault identification and protection actions through fixed current or voltage thresholds. This method has the risk of identification delay or misjudgment when facing situations such as changes in operating conditions and complex dynamic responses, and cannot meet the actual needs of rapid, accurate, and adaptive identification of DC short-circuit currents. In addition, traditional protection schemes often lack an effective parameter evaluation and adaptive correction mechanism during the fault recovery stage, resulting in potential safety hazards during the recovery process, and may even cause secondary faults in severe cases. The existing technologies still have obvious deficiencies in the real-time and accuracy of abnormal short-circuit current identification, which has become an important bottleneck restricting the safe operation of power electronic transformers in complex DC systems. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a method for protecting the short-circuit current of the DC port of a power electronic transformer to solve the problem that the short-circuit fault response mechanism in the prior art lacks real-time and self-adaptive capabilities.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for protecting the short-circuit current of the DC port of a power electronic transformer, which includes collecting current data, voltage data, and temperature data of the DC port to form an operating state data set; performing real-time analysis on the operating state data set using a density clustering algorithm to identify abnormal features related to the short-circuit current of the DC port and generating an abnormal intensity index; when an abnormal short-circuit current of the DC port is detected, generating a control instruction to drive an ultrafast electronic switch to perform a cut-off action, and recording and uploading the time, location, and abnormal parameters of the fault occurrence to generate a fault diagnosis result and a maintenance recommendation; when the fault diagnosis result and the maintenance recommendation confirm that the recovery condition is met, starting a recovery process to reconnect the power electronic transformer to the DC power supply circuit; continuously and real-time collecting operating state data, combining the operating state data set with the abnormal parameters recorded in the fault diagnosis result, and dynamically correcting the short-circuit current response mechanism using an adaptive update algorithm.

[0008] As a preferred solution of the method for protecting the short-circuit current of the DC port of the power electronic transformer according to the present invention, wherein: the current, voltage, and temperature data of the DC port are aligned according to the time stamp to generate a synchronous original data set, which is normalized to obtain a structured data table, and through periodic caching, an operating state data set is formed.

[0009] As a preferred solution of the method for protecting the short-circuit current of the DC port of the power electronic transformer according to the present invention, wherein: the specific steps for generating the abnormal intensity index are as follows.

[0010] The operating state data set is processed using a sliding window, continuously intercepting data segments of a specific time length to form short-period data sequences, and extracting multi-dimensional features to obtain a set of short-period operating state feature vectors.

[0011] Using the density clustering method to perform clustering analysis on the set of short-period operating state feature vectors to mark abnormal features.

[0012] Through a confidence evaluation mechanism, the credibility of the abnormal features is calculated to generate an abnormal intensity index.

[0013] As a preferred solution of the method for protecting the short-circuit current of the DC port of the power electronic transformer according to the present invention, wherein: the specific steps for generating the control instruction are as follows.

[0014] Extract the current intensity index from the abnormal intensity index to generate a preliminary alarm signal, and combine it with the real-time current change rate to judge the fault level and generate a level identifier.

[0015] Match the preset action strategy according to the level identifier, and determine the corresponding switch triggering method and action parameters to generate a control instruction.

[0016] As a preferred solution of the short - circuit current protection method for the DC port of the power electronic transformer described in the present invention, wherein: the steps of generating the fault diagnosis result and maintenance suggestions are as follows:

[0017] After receiving the control instruction, control the ultrafast electronic switch to disconnect the circuit to complete the cutting action, record the fault occurrence time and location, and extract abnormal parameters at the same time.

[0018] Summarize the fault time, location and abnormal parameters to form fault information, compare them using preset rules to generate a fault diagnosis result, and search for the maintenance process to generate maintenance suggestions.

[0019] As a preferred solution of the short - circuit current protection method for the DC port of the power electronic transformer described in the present invention, wherein: the steps of the recovery process are as follows:

[0020] Define the recovery conditions according to the fault diagnosis result and maintenance suggestions.

[0021] Check and verify the recovery judgment parameters of the power electronic transformer to determine whether they meet the recovery conditions.

[0022] When the recovery conditions are met, perform the power - off and re - connection operations of the power electronic transformer at the DC port.

[0023] As a preferred solution of the short - circuit current protection method for the DC port of the power electronic transformer described in the present invention, wherein: continuously and real - time collect the operation status data, combine the operation status data set with the abnormal parameters recorded in the fault diagnosis result, and dynamically correct the short - circuit current response mechanism using an adaptive update algorithm. The specific steps are as follows:

[0024] Continuously and real - time collect the updated operation status data set, and maintain the timeliness of the data through the data synchronization mechanism.

[0025] Match the updated operation status data set with the abnormal parameters in the fault diagnosis result to extract the current short - circuit current response mechanism parameters.

[0026] Dynamically adjust the current short - circuit current response mechanism parameters using an adaptive update algorithm.

[0027] As a preferred solution of the short - circuit current protection method for the DC port of the power electronic transformer described in the present invention, wherein: dynamically adjust the current short - circuit current response mechanism parameters using an adaptive update algorithm. The specific steps are as follows:

[0028] Obtain the current short - circuit current response mechanism parameters, compare them with the updated operation status data set to obtain the parameter deviation information.

[0029] Identify the current short - circuit current response mechanism parameter items to be adjusted according to the parameter offset information;

[0030] Based on the current operating state data, select the corresponding adaptive update algorithm and calculate the update values of each parameter to be adjusted;

[0031] Apply the update values to the original response mechanism parameters to generate a new set of response mechanism parameters.

[0032] In a second aspect, the present invention provides a computer device, including a memory and a processor. The memory stores a computer program, wherein: when the computer program is executed by the processor, any step of the short - circuit current protection method for the DC port of the power electronic transformer as described in the first aspect of the present invention is implemented.

[0033] In a third aspect, the present invention provides a computer - readable storage medium, on which a computer program is stored, wherein: when the computer program is executed by the processor, any step of the short - circuit current protection method for the DC port of the power electronic transformer as described in the first aspect of the present invention is implemented.

[0034] The beneficial effects of the present invention are as follows: By collecting the updated operating state data in real - time and combining the abnormal parameters in the fault diagnosis results, an adaptive update algorithm is used to dynamically adjust the short - circuit current response mechanism parameters. This step realizes the automatic adjustment of the protection mechanism under different working conditions to ensure that the protection strategy can always adapt to the current operating state. Its function is to optimize the protection mechanism in real - time, with strong adaptability and response ability. It can not only reduce the mis - operations and missed operations caused by parameter changes, but also continuously and effectively protect the power electronic transformer under different changes such as load, ambient temperature, and voltage fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following - described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 It is a flowchart of the short - circuit current protection method for the DC port of the power electronic transformer in the present invention.

[0037] Figure 2 It is a flowchart of the generation of the abnormal intensity index in the present invention.

[0038] Figure 3 It is a flowchart of fault diagnosis and recovery in the present invention.

[0039] Figure 4This is the flowchart for dynamically correcting the response mechanism in the present invention. Detailed implementation manners

[0040] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following detailed description of the specific implementation manners of the present invention will be provided in conjunction with the accompanying drawings of the specification.

[0041] In the following description, many specific details are set forth to facilitate a thorough understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0042] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or alternative embodiments that are mutually exclusive of other embodiments.

[0043] Refer to Figures 1 to 4 , this embodiment provides a method for protecting the short-circuit current of the DC port of a power electronic transformer, including the following steps:

[0044] S1. Align the current, voltage, and temperature data of the DC port according to the time stamp to generate a synchronous original data set. After normalization processing, a structured data table is obtained, and through periodic caching, an operating state data set is formed.

[0045] It should be noted that the current data, voltage data, and temperature data of the DC port are respectively collected by a high-frequency sampling device, and each type of data is accompanied by a corresponding sampling time stamp during collection. After collection, the three types of data are respectively sorted according to the time stamp field, and a unified reference time granularity is set. For example, with a 100-millisecond or 1-second alignment period, interpolation or discarding of redundant samples is performed within each time granularity to form corresponding data values of different physical quantities at the same time node, obtaining a synchronous original data set of current data, voltage data, and temperature data;

[0046] Perform normalization processing on each field in the synchronous original data set. The processing methods include but are not limited to maximum-minimum normalization, mean-variance standardization, or Z-score standardization, and the specific method can be determined according to the data fluctuation characteristics. For example, scale the value range of the current data to the interval [0, 1] through linear transformation, and perform zero-mean unit-variance standardization on the temperature data to ensure the comparability of the three types of data on a unified scale. All normalization processing is synchronously performed while retaining the original time stamp field;

[0047] After processing, the data is written into a structured data table in chronological order. The structured data table uses the timestamp as the primary key and has current, voltage, and temperature fields to form a standardized data structure. To support subsequent real-time analysis tasks, a fixed cache cycle is set, such as triggering a data refresh every 5 or 10 seconds, and periodically writing the data in the latest time period into the operating status data set, and removing historical data outside the cache window to ensure that the operating status data set is always up to date and the data volume is stable.

[0048] S2. Use anomaly recognition algorithm to perform real-time analysis on the operating status data set, identify abnormal features related to the DC port short-circuit current and generate anomaly intensity indicators.

[0049] The running status data set is processed by sliding window, and data segments of specific time length are continuously intercepted to form a short-period data sequence. Multidimensional features are extracted to obtain a set of short-period running status feature vectors.

[0050] Specifically, the time length of the sliding window is set in the operating status data set, for example, each window length is set to 10 seconds, the step length is set to 1 second, the operating status data set is divided into time series, and each 10-second data segment is intercepted from the beginning in chronological order, and each data segment contains all current data, voltage data and temperature data within the time range. Each time the sliding window slides forward for 1 second, the interception operation is repeated to form multiple continuous short-period data sequences;

[0051] Multidimensional features are extracted for each short-period data sequence, and the extracted multidimensional features include statistical features, change features, and frequency domain features. Statistical features include the mean, standard deviation, range, maximum value, and minimum value of current data, voltage data, and temperature data. For example, the average value and standard deviation of the current value in each data segment are calculated. Change features include the mean and standard deviation, the number of maximum / minimum points, and the change slope of the first-order difference sequence of current data, voltage data, and temperature data; the frequency domain features use fast Fourier transform (FFT) to transform the current data, voltage data, and temperature data respectively, and extract the frequency component with the largest amplitude as the frequency domain feature, for example, the amplitude of the first 5 frequencies of the energy distribution is taken to form a spectrum feature vector;

[0052] All extracted features are combined according to current features, voltage features, and temperature features, and spliced into a unified format of DC port operation status joint feature vector, and associated with the starting timestamp of the short-cycle data sequence. The above operation is repeated to finally obtain the corresponding short-cycle operation status feature vector set.

[0053] The density clustering method is used to perform cluster analysis on the short-period operation status feature vector set and mark abnormal features.

[0054] Specifically, key parameters of the density clustering method are set, including the neighborhood radius threshold and the minimum number of neighborhood samples MinPts; subsequently, for each feature vector in the short-cycle operation state feature vector set , the Euclidean distance from all other feature vectors is calculated, and the expression is: ;

[0055] where represents the Euclidean distance between the short-cycle operation state feature vector and the short-cycle operation state feature vector , represents the dimensionality of the short-cycle operation state feature vector, represents the calculation of the distance component in the th dimension, represents the th short-cycle operation state feature vector in the short-cycle operation state feature vector set, represents the th short-cycle operation state feature vector in the short-cycle operation state feature vector set;

[0056] The number of short-cycle operation state feature vectors that satisfy is counted and denoted as represents the number of short-cycle operation state feature vectors contained in the neighborhood with the short-cycle operation state feature vector as the center and the radius of ; when is satisfied, the short-cycle operation state feature vector is used as a core point, and all short-cycle operation state feature vectors in the neighborhood are merged into the same cluster, and the density-reachable feature vectors are continuously expanded outward until the cluster no longer expands; when a short-cycle operation state feature vector fails to be assigned to any cluster and is satisfied, the short-cycle operation state feature vector is marked as an abnormal feature point. After the clustering attribution division of all short-cycle operation state feature vectors is completed, all cluster subsets and the corresponding short-cycle operation state feature vectors are output, and at the same time, all short-cycle operation state feature vectors that are not assigned to valid clusters are marked as abnormal features.

[0057] The credibility of the abnormal feature is calculated through a confidence evaluation mechanism to generate an abnormal intensity index.

[0058] Specifically, the average Euclidean distance is calculated, and the expression is:

[0059] ;

[0060] where Indicates the number of all short - cycle operation status feature vectors; Indicates the ones involved in the calculation and Belong to the same clustering subset Of the short - cycle operation status feature vectors ;

[0061] Construct a confidence function For quantifying the degree of abnormality, and the expression is:

[0062] ;

[0063] Among them, Indicates the final abnormality intensity index of the short - cycle operation status feature vector For comprehensively evaluating the credibility of it as an abnormal feature; Indicates the weight coefficient of the neighborhood density factor, reflecting the influence degree of neighborhood sparsity on the abnormality intensity, and the value range is usually ; Indicates the weight coefficient of the Euclidean distance factor, reflecting the influence degree of the average distance from other feature vectors within the cluster on the abnormality intensity, and the value range is usually , and there is ;

[0064] For all Values, perform maximum - minimum normalization processing to generate the corresponding abnormality intensity index, and the expression is:

[0065] ;

[0066] Among them, Indicates the normalized abnormality intensity index of the short - cycle operation status feature vector , and the value range is , for uniformly measuring the degree of abnormality between different short - cycle operation status feature vectors, and the larger the value, the more abnormal; Indicates the minimum value of all short - cycle operation status feature vector abnormality intensity indexes ; Indicates the maximum value of all short - cycle operation status feature vector abnormality intensity indexes , Indicates the abnormality intensity index of the short - cycle operation status feature vector.

[0067] S3. When detecting an abnormality in the DC - port short - circuit current, generate a control instruction.

[0068] Extract the current intensity index from the abnormality intensity index, generate a preliminary alarm signal, and combine it with the real - time current change rate to judge the fault level and generate a level identifier.

[0069] Specifically, extract the normalized anomaly intensity index corresponding to the current moment from the anomaly intensity index sequence generated in the previous stage. ; Then, compare this normalized anomaly intensity index with the preset alarm threshold. If , then generate a preliminary alarm signal, where is an example preset threshold, such as = 0.75; Next, obtain the current value of the DC port current at the current moment from the structured data table and the current value at the previous moment , and calculate the current change rate , and the expression is: ;

[0070] Use the normalized anomaly intensity index corresponding to the preliminary alarm signal and the current change rate as the combined input, and use multi-condition rules to judge the fault level. For example: when and , mark it as "Level 1 fault"; when and , mark it as "Level 2 fault"; when and , mark it as "Level 3 fault"; Output the judgment result as the level identifier.

[0071] Match the preset action strategy according to the level identifier, and determine the corresponding switch trigger method and action parameters to generate a control instruction.

[0072] It should be noted that read the fault level from the current fault level identifier, such as "Level 1 fault", "Level 2 fault" or "Level 3 fault"; then find the preset action strategy item corresponding to the fault level identifier in the action strategy. The action strategy item includes information such as the switch type, trigger method, trigger delay parameter and action duration parameter. For example, the action strategy corresponding to "Level 1 fault" is "Trigger the circuit breaker to trip", "The trigger method is voltage drop", "The trigger delay is 100 ms", "The action duration is 500 ms"; then assemble the control instruction fields according to the switch type and trigger method in the action strategy, including the target switch address, action type field, trigger condition field and action parameter field; finally, write the generated control instruction into the output instruction buffer queue and prepare to enter the control execution process.

[0073] S4. Drive the ultrafast electronic switch to perform the cut-off action, record and upload the time, location and abnormal parameters of the fault occurrence, and generate the fault diagnosis result and maintenance suggestion.

[0074] After receiving the control instruction, the ultrafast electronic switch is controlled to disconnect the circuit to complete the cutting action, and the fault occurrence time and location are recorded. At the same time, abnormal parameters are extracted.

[0075] It should be noted that the target switch address and action type field in the control instruction are read, and the action type is parsed as "disconnect" and the target device is the ultrafast electronic switch; then a disconnection trigger signal is sent to the target ultrafast electronic switch to start its internal opening logic and complete the rapid cutting of the circuit; at the same time as the action is completed, the current timestamp is recorded by the clock module as the fault occurrence time, and the fault occurrence location is located according to the line number or sensor identifier included in the control instruction; finally, multi-dimensional abnormal parameters within a set time window before and after the fault occurrence moment are extracted from the currently collected original waveform data such as current and voltage, such as current peak value, voltage drop amplitude, current change rate, etc., and summarized to form abnormal parameters.

[0076] The fault time, location and abnormal parameters are summarized to form fault information, and compared using preset rules to generate a fault diagnosis result, and the maintenance process is searched to generate maintenance suggestions.

[0077] Specifically, the fault occurrence time, fault location identifier and the currently extracted abnormal parameters (such as current peak value, voltage drop amplitude, current change rate) are formed into structured fault information in a unified format; then the preset rules are called to compare the structured fault information. The preset rules are constructed by statistical analysis of historical fault cases, and the rule content includes mapping relationships such as abnormal parameter threshold ranges, fault time period characteristics, and typical fault types corresponding to locations. For example, it is set that when the current peak value is greater than 300A and the current change rate exceeds 500A / ms, it is judged as a short-circuit fault; during the comparison process, each rule is conditionally matched, and the rule item with the highest matching degree is selected to generate the corresponding fault diagnosis result; after the diagnosis result is generated, based on the current diagnosis result, the matching maintenance suggestions are retrieved from the preset maintenance process database. The maintenance process database establishes maintenance step entries indexed by fault types. For example, the maintenance suggestions for short-circuit faults include: power-off inspection, insulation test, fuse replacement and line re-inspection; finally, the fault diagnosis result and the corresponding maintenance suggestions are output.

[0078] S5. When it is confirmed that the fault diagnosis result and maintenance suggestions meet the recovery conditions, start the recovery process and reconnect the power electronic transformer to the DC power supply circuit.

[0079] Define the recovery conditions according to the fault diagnosis result and maintenance suggestions.

[0080] Specifically, collect common fault types, such as "bus grounding", "feeder short circuit", "transformer overload", etc., and sort out the typical recovery operation processes corresponding to each fault type. Extract the maintenance steps and judgment conditions from them, such as the completion status of operations like "replace faulty components", "detect insulation value", "confirm load drop", etc. as binary flag bits. Then, using the fault type as the primary key, construct the corresponding recovery condition expression. For example, for the "feeder short circuit" fault, the recovery condition expression is "fuse replacement completion flag = 1 and cable insulation detection passed flag = 1 and current restored to rated value flag = 1". Next, organize all fault types and their corresponding recovery conditions to form a fault recovery logic rule table, and continuously supplement and optimize it during subsequent operation and maintenance processes. During application, extract the fault type label from the fault diagnosis result, such as "short circuit fault", "grounding anomaly", or "overload operation", and match the maintenance operation items listed in the maintenance suggestions. Extract the operation completion status flag bits for each item, such as "fuse replacement completion flag = 1", "insulation resistance detection passed flag = 1", "line voltage restored to normal range flag = 1". Finally, based on the recovery condition expression corresponding to the current fault type in the fault recovery logic rule table, perform a logical combination judgment on each flag bit. If the logical judgment result is true, mark it as "meeting the recovery conditions"; otherwise, maintain the fault isolation state.

[0081] Check and verify the recovery judgment parameters of the power electronic transformer to determine whether they meet the recovery conditions.

[0082] Preferably, extract the fault type label from the fault diagnosis result and determine whether it belongs to the power electronic transformer type of fault, such as "DC side bus undervoltage", "AC side overcurrent", "power module overtemperature", etc. Then, according to the power electronic transformer recovery condition expression, extract the preset parameter items, such as "bus voltage value", "power module temperature", "input and output current values", etc. Next, based on the equipment factory technical parameter manual, industry standard documents, and operation and maintenance experience data of the power electronic transformer, set the recovery judgment thresholds for each parameter item. For example, compare the current bus voltage value with the lower limit of 300V, the power module temperature with the upper limit of 85°C, and the output current value with the rated value. Subsequently, combine the comparison results logically according to the power electronic transformer recovery condition expression, such as "bus voltage value ≥ 300V and power module temperature ≤ 85°C and output current value within the rated range". Finally, judge whether the power electronic transformer meets the recovery conditions based on the logical combination result. If all conditions are met, the result is "meeting the recovery conditions"; if the conditions are not met, the result is "not meeting the recovery conditions".

[0083] When the recovery conditions are met, perform the power-off and reconnection operations on the DC port power electronic transformer.

[0084] Preferably, a control instruction is issued to turn off the DC-side input switch of the DC-port power electronic transformer, disconnect the main circuit power supply, and record the timestamp of the disconnection operation; then, it is confirmed through the acquisition device that the DC voltage has dropped to a safe level, for example, it is confirmed that the voltage is lower than 50V, and the states of key devices are monitored to be idle or non-excited; then, a reconnect preparation process is executed, including voltage pre-charging of the main circuit of the DC-port power electronic transformer, buffer charging of the bus capacitor, gate drive initialization, etc.; after all the preparation actions are completed, a control instruction is sent to close the DC-side input switch, and the power electronic transformer is reconnected to the DC power supply; finally, the initial operation data after reconnection is read and recorded, for example, key parameters such as voltage, current, and temperature within 5 seconds after reconnection are recorded for subsequent stability analysis or comparison.

[0085] S6. Continuously and real-time collect the operation status data, and combine the operation status data set with the abnormal parameters recorded in the fault diagnosis result, and use an adaptive update algorithm to dynamically correct the short-circuit current response mechanism.

[0086] Continuously and real-time collect the updated operation status data set, and maintain the timeliness of the data through a data synchronization mechanism.

[0087] It should be noted that a collection instruction is configured to regularly read operation status data such as voltage, current, power, temperature, and insulation resistance value at a sampling period of 100 ms and write them into the operation status data set; then, a queue caching mechanism based on the timestamp is established to bind the collection time and the data value, for example, it is stored in the format of "202X-04-15 10:30:00.100 - voltage value = 420V"; then, an existing time synchronization protocol such as the Network Time Protocol (NTP) is used to align the clocks of the collection terminals to ensure the time consistency among multiple data sources; then, the new data in the operation status data set is directionally synchronized to the target processing end through a publish-subscribe mechanism or HTTP push, etc., to ensure that the latest data can be reached within 200 ms; finally, the synchronization result is verified, including comparing the continuity of the timestamps, the integrity of the fields, and the legality of the data values, for example, it is judged that the synchronized voltage value should be between 300 - 500V, and an abnormal record is triggered and re-synchronized if it exceeds the range.

[0088] Match the updated operation status data set with the abnormal parameters in the fault diagnosis result, and extract the current short-circuit current response mechanism parameters.

[0089] It should be noted that in the fault diagnosis result, the fault type label to which the abnormal parameter belongs is "short - circuit fault"; then extract the characteristic items related to the short - circuit fault from the abnormal parameters, such as "maximum short - circuit current value", "short - circuit current duration", "current rise rate", etc.; then search for the current data sequence within the corresponding time - stamp interval in the updated operating - state dataset, and extract the current change curve within 500 ms before and after the fault; then extract the corresponding characteristic values by name, for example, calculate the maximum short - circuit current value as the current peak value within this interval, the short - circuit current duration as the time - period length during which the current is greater than twice the rated value, and the current rise rate as the maximum slope of the current rising from the steady state to the peak value; finally, mark the extracted "maximum short - circuit current value", "short - circuit current duration", and "current rise rate" as the current short - circuit current response mechanism parameters.

[0090] Use an adaptive update algorithm to dynamically adjust the current short - circuit current response mechanism parameters.

[0091] Furthermore, obtain the current short - circuit current response mechanism parameters, compare them with the updated operating - state dataset, and obtain the parameter offset information.

[0092] It should be noted that extract each numerical value in the current short - circuit current response mechanism parameters, including the maximum short - circuit current value, short - circuit current duration, and current rise rate, for example, "maximum short - circuit current value = 420 A", "short - circuit current duration = 180 ms", "current rise rate = 2800 A / s"; then in the updated operating - state dataset, find the historical statistical reference value or rated threshold of the corresponding parameter, for example, "maximum short - circuit current value reference value = 400 A", "short - circuit current duration reference value = 150 ms", "current rise rate reference value = 2500 A / s"; then calculate the offset of each parameter item by item, for example, offset = current value−reference value, and get "maximum short - circuit current value offset = 20 A", "short - circuit current duration offset = 30 ms", "current rise rate offset = 300 A / s"; finally, form the parameter offset information with each offset and output it, including the offset direction and the magnitude of the offset value.

[0093] Identify the current short - circuit current response mechanism parameter items that need to be adjusted according to the parameter offset information.

[0094] It should be noted that the offset values and offset directions of each parameter in the read parameter offset information are read, for example, "Maximum short-circuit current value offset = +20A", "Short-circuit current duration offset = +30ms", "Current rise rate offset = +300A / s"; then the parameter offset threshold range is set, for example, "Allowable offset range of maximum short-circuit current value ±10A", "Allowable offset range of short-circuit current duration ±20ms", "Allowable offset range of current rise rate ±200A / s"; then the offset of each parameter is compared with its corresponding allowable offset range to identify the parameter items that exceed the threshold range. For example, it is determined that "Maximum short-circuit current value offset = +20A > +10A" is out of limit, "Short-circuit current duration offset = +30ms > +20ms" is out of limit, "Current rise rate offset = +300A / s > +200A / s" is out of limit; finally, the parameter items that exceed the allowable offset range are marked as the response mechanism parameter items to be adjusted.

[0095] Based on the current operating state data, select the corresponding adaptive update algorithm to calculate the update values of each parameter to be adjusted.

[0096] It should be noted that the current operating state data is analyzed to extract the data items related to the parameters to be adjusted, such as "Current load current", "Voltage fluctuation", "Temperature change", etc.; then an adaptive update algorithm suitable for the current situation is selected, such as "Least mean square error algorithm", "Recursive least squares algorithm", etc.; then the extracted data items are used as the input of the algorithm and calculated according to the selected adaptive update algorithm. For example, for the least mean square error algorithm, the error values of each parameter to be adjusted (such as the updated maximum short-circuit current value, short-circuit duration, and current rise rate) are calculated, and the parameters are adjusted according to the error values; then according to the calculation results, the update values of each parameter to be adjusted are obtained, and finally the update values of each parameter to be adjusted calculated are applied to the current operation to ensure the adaptability of the response mechanism.

[0097] Apply the update values to the original response mechanism parameters to generate a new set of response mechanism parameters.

[0098] It should be noted that real-time acquisition data from the initial configuration and operating status of the device is obtained, including response mechanism parameters such as "maximum short-circuit current value", "response time", "voltage fluctuation range", etc. Then, the updated values of each parameter to be adjusted calculated by the adaptive update algorithm are obtained, such as "current rise rate", "current threshold", etc.; Next, each updated value is respectively replaced with the corresponding item of the original response mechanism parameter to ensure that each value in the original response mechanism parameter is replaced by the updated value; Subsequently, the integrity and consistency of the new response mechanism parameter set are verified to ensure that all parameter items have been successfully updated and there is no missing or incorrect data; Finally, a new response mechanism parameter set is generated, which will be stored as the latest response mechanism parameter set used in the current operation and used for subsequent calculations or adjustments.

[0099] This embodiment also provides a computer device, which is applicable to the case of the DC port short-circuit current protection method of the power electronic transformer, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the DC port short-circuit current protection method of the power electronic transformer proposed in the above embodiment.

[0100] The computer device can be a terminal. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a carrier network, NFC (Near Field Communication), or other technologies. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a button, a trackball, or a touchpad set on the outer shell of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0101] This embodiment also provides a storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the method for protecting the short-circuit current of the DC port of the power electronic transformer as proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (Static Random Access Memory, abbreviated as SRAM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, abbreviated as EEPROM), erasable programmable read-only memory (Erasable Programmable Read Only Memory, abbreviated as EPROM), programmable read-only memory (Programmable Red-Only Memory, abbreviated as PROM), read-only memory (Read-Only Memory, abbreviated as ROM), magnetic memory, flash memory, magnetic disk or optical disc.

[0102] In summary, the present invention: real-time collects the updated operation state data and combines the abnormal parameters in the fault diagnosis result, and uses an adaptive update algorithm to dynamically adjust the short-circuit current response mechanism parameters. This step realizes the automatic adjustment of the protection mechanism under different working conditions to ensure that the protection strategy can always adapt to the current operation state. The function is to optimize the protection mechanism in real time, with strong adaptability and response ability. It can not only reduce the misoperation and missed operation caused by parameter changes, but also continuously and effectively protect the power electronic transformer under different changes such as load, ambient temperature and voltage fluctuation.

[0103] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for protecting the short-circuit current of the DC port of a power electronic transformer, characterized in that: including, collecting the current data, voltage data, and temperature data of the DC port to form an operating state data set; performing real-time analysis on the operating state data set using a density clustering algorithm to identify abnormal features related to the short-circuit current of the DC port and generate an abnormal intensity index; The specific steps are as follows. Performing a sliding window process on the operating state data set, continuously intercepting data segments of a specific time length to form short-period data sequences, and extracting multi-dimensional features to obtain a set of short-period operating state feature vectors; Using the density clustering method to perform clustering analysis on the set of short-period operating state feature vectors and mark abnormal features; Calculating the credibility of the abnormal features through a confidence evaluation mechanism to generate an abnormal intensity index; When an abnormal short-circuit current of the DC port is detected, generating a control command to drive the ultrafast electronic switch to perform a cut-off action, and recording and uploading the time, location, and abnormal parameters of the fault occurrence to generate a fault diagnosis result and a maintenance recommendation; When an abnormal short-circuit current of the DC port is detected, generating a control command. The specific steps are as follows. Extracting the current intensity index from the abnormal intensity index to generate a preliminary alarm signal, and combining it with the real-time current change rate to judge the fault level and generate a level identifier; Matching the preset action strategy according to the level identifier, determining the corresponding switch triggering method and action parameters, and generating a control command; When the fault diagnosis result and the maintenance recommendation confirm that the recovery conditions are met, starting the recovery process to reconnect the power electronic transformer to the DC power supply circuit; Continuously and real-time collecting the operating state data, combining the operating state data set with the abnormal parameters recorded in the fault diagnosis result, and using an adaptive update algorithm to dynamically correct the short-circuit current response mechanism; The specific steps are as follows. Continuously and real-time collecting the updated operating state data set and maintaining the timeliness of the data through a data synchronization mechanism; Matching the updated operating state data set with the abnormal parameters in the fault diagnosis result to extract the current short-circuit current response mechanism parameters; Using an adaptive update algorithm to dynamically adjust the current short-circuit current response mechanism parameters.

2. The DC port short-circuit current protection method for a power electronic transformer according to claim 1, characterized in that: Aligning the current, voltage, and temperature data of the DC port according to the time stamp to generate a synchronized original data set, obtaining a structured data table through normalization processing, and forming an operating state data set through periodic caching.

3. The short-circuit current protection method for the DC port of the power electronic transformer according to claim 1, characterized in that: The specific steps for generating the fault diagnosis result and the maintenance recommendation are as follows. After receiving the control command, controlling the ultrafast electronic switch to disconnect the circuit to complete the cut-off action, recording the fault occurrence time and location, and simultaneously extracting the abnormal parameters; Summarizing the fault time, location, and abnormal parameters to form fault information, comparing them using preset rules to generate a fault diagnosis result, and searching for the maintenance process to generate a maintenance recommendation.

4. The short-circuit current protection method for the DC port of the power electronic transformer according to claim 1, characterized in that: The specific steps of the recovery process are as follows. Defining the recovery conditions according to the fault diagnosis result and the maintenance recommendation; Checking and verifying the recovery determination parameters of the power electronic transformer to determine whether they meet the recovery conditions; When the recovery conditions are met, performing the power-off and reconnection operations of the power electronic transformer at the DC port.

5. The short-circuit current protection method for the DC port of the power electronic transformer according to claim 1, characterized in that: Using an adaptive update algorithm to dynamically adjust the current short-circuit current response mechanism parameters. The specific steps are as follows. Obtain the current short-circuit current response mechanism parameters, compare them with the updated operating state data set, and obtain the parameter offset information; Identify the current short-circuit current response mechanism parameter items to be adjusted according to the parameter offset information; Based on the current operating state data, select the corresponding adaptive update algorithm and calculate the update values of each parameter to be adjusted; Apply the update values to the original response mechanism parameters to generate a new response mechanism parameter set.

6. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that: When the processor executes the computer program, the steps of the short-circuit current protection method for the DC port of the power electronic transformer according to any one of claims 1 to 5 are implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, the steps of the short-circuit current protection method for the DC port of the power electronic transformer according to any one of claims 1 to 5 are implemented.

Images