Fault symptom rapid identification method of converter transformer valve side external construction frequency resonance test and related device

Abstract

The invention discloses a fault symptom rapid identification method, a fault symptom rapid identification device, a fault symptom rapid identification device and a computer readable storage medium for a converter transformer valve side external construction frequency resonance test, and the method comprises the steps: firstly, carrying out the real-time synchronous collection of multi-dimensional parameters, such as voltage, current, local discharge amount and waveform distortion; on the basis, a multi-parameter comprehensive criterion system is established, and fault type priorities are configured, so that accurate classification and identification of different types of fault symptoms are realized; a preset linkage disposal operation sequence is automatically triggered according to an identification result, and an automatic closed loop from monitoring and early warning to active protection is formed; and finally, through whole-process data recording and report generation, the traceable management of the fault information is perfected. According to the whole scheme, multi-source information fusion and intelligent decision control are combined, and systematic technical support is provided for early warning and quick response of faults in the test process.

Description

Technical Field

[0001] This invention belongs to the field of power equipment testing technology, and more specifically, relates to a method for rapid identification of fault symptoms in a converter transformer valve side external construction frequency resonance test, a device for rapid identification of fault symptoms in a converter transformer valve side external construction frequency resonance test, a fault symptom rapid identification device, and a computer-readable storage medium. Background Technology

[0002] Converter transformers are core equipment in high-voltage direct current transmission systems. Their valve-side windings need to withstand the combined AC and DC voltages. The insulation structure design is complex and the insulation margin requirements are high. During on-site commissioning tests or post-maintenance retests, it is usually necessary to conduct an external construction frequency withstand voltage test on the valve-side windings to verify their insulation performance. Due to the large capacity of converter transformers and the high capacitance of the valve-side windings, on-site tests generally adopt series resonance or parallel resonance methods to reduce the test power supply capacity requirements.

[0003] Currently, the external construction frequency resonance test of the converter transformer valve side has the following problems in actual operation: On the one hand, there is a lack of systematic criteria for identifying abnormal signs. During the test, abnormal phenomena such as sudden increase in partial discharge, abnormal rise in test current, and distortion of voltage or current waveforms may occur. However, the existing test procedures are not clear enough on the criteria for judging the above abnormalities. Test personnel mainly rely on personal experience to make judgments, which are highly subjective and have a slow response speed. On the other hand, it is difficult to quickly distinguish the fault types. Different fault types such as insulation breakdown, surface flashover, test wiring errors, and the development of internal defects in equipment may have similar external manifestations in the initial stage. A single parameter is not enough to accurately distinguish the nature of the fault, which can easily lead to misjudgment or omission, resulting in inappropriate handling measures. Overreaction will cause unnecessary test interruption and waste of resources, while underreaction may cause the fault to expand and endanger equipment safety or even personnel safety.

[0004] Therefore, how to improve the speed of fault symptom identification, achieve accurate identification and graded response of typical anomalies through multi-parameter comprehensive criteria, and improve the safety and efficiency of the test process are key issues of concern to those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a method for rapid identification of fault symptoms in the external construction frequency resonance test of the converter valve side, a device for rapid identification of fault symptoms in the external construction frequency resonance test of the converter valve side, a fault symptom rapid identification equipment, and a computer-readable storage medium, and to improve the speed of fault symptom identification by using multi-parameter comprehensive criteria to achieve accurate identification and graded response of typical anomalies, thereby improving the safety and efficiency of the test process.

[0006] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a method for rapid identification of fault symptoms during external construction frequency resonance testing of converter valves, comprising: S1, During the power frequency resonance test, multiple electrical parameters of the test system are synchronously acquired in real time to obtain real-time monitoring data of multiple parameters; wherein, the real-time monitoring data of multiple parameters includes voltage parameters, current parameters, partial discharge quantity, and waveform distortion index; S2, based on the real-time monitoring data of the multi-parameters, the fault symptoms are classified and identified using multi-parameter comprehensive criteria to obtain the fault symptom types; wherein, the fault symptom types include: insulation breakdown symptoms, surface flashover symptoms, wiring error symptoms and internal equipment fault symptoms. When the criteria for multiple types of fault symptoms are met simultaneously, the fault symptoms are judged in the order of priority: insulation breakdown, surface flashover, internal equipment fault, and wiring error. S3, based on the type of fault symptom, trigger the corresponding linkage handling operation sequence; S4 records all monitoring data and event logs throughout the entire experiment and generates an experiment process report based on the recorded data to support diagnostic analysis.

[0007] Optionally, in step S1, the voltage parameters are measured in real time using a capacitive voltage divider or a photoelectric voltage transformer, including the instantaneous value of the test voltage, the effective value of the voltage, and the voltage phase angle. The current parameters are measured in real time using a current transformer, including the instantaneous value of the test current, the effective value of the current, the current phase angle, and the current harmonic content. The partial discharge quantity is monitored in real time using at least one of the following methods: ultrasonic method, ultra-high frequency method, or pulse current method, including the apparent value of the discharge quantity and the frequency of discharge pulses per unit time.

[0008] Optionally, S1 further includes: setting monitoring parameter thresholds; wherein the monitoring parameter thresholds include: the normal fluctuation range of the effective voltage value is ±3% of the set value; the normal fluctuation threshold of the current is ±5% of the steady-state current value, and the normal value of the total harmonic distortion rate of the current is less than 5%; the reference threshold for partial discharge is 500pC, the reference threshold for discharge frequency is 10 times / second, and when the partial discharge or discharge frequency exceeds 200% of the reference threshold, it is determined as a sudden increase in partial discharge; the normal threshold for voltage waveform distortion rate is 2%, and the normal threshold for current waveform distortion rate is 5%, and when the distortion rate exceeds 150% of the normal threshold, it is determined as abnormal waveform distortion.

[0009] Optionally, the identification criteria for insulation breakdown symptoms in S2 include the following three conditions: the effective value of the test current rises by more than 50% of the steady-state value within 100ms, the effective value of the test voltage falls by more than 20% of the set value within 100ms, and the partial discharge increases suddenly to more than 300% of the reference threshold within 200ms; the confidence level is high when all three conditions are met, medium when the first two conditions are met but the third condition is not met, and low when only the first condition is met.

[0010] Optionally, the handling sequence for insulation breakdown symptoms in S3 includes: triggering a rapid voltage reduction command, controlling the voltage regulator to reduce the voltage at the maximum rate, and reducing the test voltage to below 30% of the set value within 500ms; cutting off the main circuit of the test power supply to perform an emergency shutdown after the voltage drops to a safe level; isolating the test sample and confirming safety after the discharge time is not less than 5 minutes; and starting the fault diagnosis program and retrieving the data recorded in S4 for analysis.

[0011] Optionally, the handling sequence for surface flashover symptoms in S3 includes: triggering a rapid voltage reduction command to reduce the test voltage to below 50% of the set value within 1 second; maintaining the low voltage state for 10 seconds to confirm whether the abnormal phenomenon has disappeared; if the abnormality disappears, re-increasing the voltage to 80% of the original test voltage at a rate not exceeding 50% of the rated voltage increase rate for verification; if the abnormality recurs, executing a shutdown and performing an isolation check, the isolation check including checking the surface condition of the insulator, checking the safe distance between the lead and the grounding body, and checking for foreign objects or dirt.

[0012] Optionally, in S4, the monitoring data recording records the effective voltage value, effective current value, partial discharge, and waveform distortion rate at a frequency of not less than once per second, and continuously stores the instantaneous waveform data of voltage and current at a sampling frequency of not less than 10kHz. The timestamp accuracy of the data storage is not less than 1ms. The event log records include the start and end times of the test, the voltage setpoints and actual values ​​at each stage, the fault symptom identification results and their identification time and confidence level, and the trigger time and execution content of the linkage handling operation.

[0013] This application also provides a rapid fault symptom identification device for external construction frequency resonance tests on the converter transformer valve side, including: The monitoring data acquisition module is used to synchronously collect multiple electrical parameters of the test system in real time during the power frequency resonance test to obtain multi-parameter real-time monitoring data; wherein, the multi-parameter real-time monitoring data includes voltage parameters, current parameters, partial discharge quantity, and waveform distortion index; The multi-parameter classification module is used to classify and identify fault symptoms based on the real-time monitoring data of the multi-parameters and to obtain the fault symptom types. The fault symptom types include: insulation breakdown symptoms, surface flashover symptoms, wiring error symptoms, and internal equipment fault symptoms. When the criteria for multiple types of fault symptoms are met simultaneously, the fault symptoms are judged in the order of priority: insulation breakdown, surface flashover, internal equipment fault, and wiring error. The fault linkage handling module is used to trigger the corresponding linkage handling operation sequence according to the fault symptom type; The event logging module is used to fully record monitoring data and event logs throughout the entire experiment, and generate an experiment process report based on the recorded data to support diagnostic analysis.

[0014] This application also provides a device for rapid identification of fault symptoms, including: Memory, used to store computer programs; A processor, used to implement the steps of the fault symptom rapid identification method as described above when executing the computer program.

[0015] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the fault symptom rapid identification method described above.

[0016] This application provides a method for rapid identification of fault symptoms during external construction frequency resonance testing of a converter transformer valve, including: S1, During the power frequency resonance test, multiple electrical parameters of the test system are synchronously acquired in real time to obtain real-time monitoring data of multiple parameters; wherein, the real-time monitoring data of multiple parameters includes voltage parameters, current parameters, partial discharge quantity, and waveform distortion index; S2, based on the real-time monitoring data of the multi-parameters, the fault symptoms are classified and identified using multi-parameter comprehensive criteria to obtain the fault symptom types; wherein, the fault symptom types include: insulation breakdown symptoms, surface flashover symptoms, wiring error symptoms and internal equipment fault symptoms. When the criteria for multiple types of fault symptoms are met simultaneously, the fault symptoms are judged in the order of priority: insulation breakdown, surface flashover, internal equipment fault, and wiring error. S3, based on the type of fault symptom, trigger the corresponding linkage handling operation sequence; S4 records all monitoring data and event logs throughout the entire experiment and generates an experiment process report based on the recorded data to support diagnostic analysis.

[0017] It has the following beneficial effects: By synchronously acquiring multiple parameters in real time, including voltage, current, partial discharge, and waveform distortion, the shortcomings of traditional single-parameter monitoring in terms of insufficient information dimensions are overcome, providing comprehensive data support for fault symptom identification. Employing multi-parameter comprehensive criteria and setting fault type priority orders effectively improves the accuracy of fault symptom classification and identification, reducing the risk of misjudgment and missed judgment. Triggering corresponding linkage and handling operation sequences based on the identification results realizes automated closed-loop control from fault identification to response and handling, significantly shortening the reaction time of manual intervention. This facilitates timely implementation of protective measures in the early stages of fault development, reducing equipment damage and the risk of test accidents. Simultaneously, through full-process data recording and report generation, a traceable data foundation is provided for fault cause diagnosis and test plan optimization. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 A flowchart illustrating a method for rapid identification of fault symptoms during an external construction frequency resonance test on the converter valve side, provided in an embodiment of this application; Figure 2 A schematic diagram of a fault symptom rapid identification device for an external construction frequency resonance test of a converter valve side provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the fault symptom rapid identification device provided in the embodiments of this application. Detailed Implementation

[0020] The purpose of this application is to provide a method for rapid identification of fault symptoms in the external construction frequency resonance test of the converter valve side, a device for rapid identification of fault symptoms in the external construction frequency resonance test of the converter valve side, a fault symptom rapid identification equipment, and a computer-readable storage medium, and to improve the speed of fault symptom identification by using multi-parameter comprehensive criteria to achieve accurate identification and graded response of typical anomalies, thereby improving the safety and efficiency of the test process.

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] The following embodiment illustrates a method for rapid identification of fault symptoms during external construction frequency resonance testing of a converter transformer valve, as provided in this application.

[0023] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating a method for rapid identification of fault symptoms during an external construction frequency resonance test on the converter valve side, as provided in an embodiment of this application.

[0024] In this embodiment, the method may include: S1, during the power frequency resonance test, multiple electrical parameters of the test system are synchronously acquired in real time to obtain multi-parameter real-time monitoring data; among them, the multi-parameter real-time monitoring data includes voltage parameters, current parameters, partial discharge quantity, and waveform distortion index; During the external construction frequency resonant test on the valve side of the converter transformer, the test system mainly consists of a voltage regulator, excitation transformer, resonant reactor, valve-side winding of the converter transformer under test, and related measuring equipment. This step involves deploying multiple sensors at key nodes in the test circuit to achieve real-time synchronous acquisition of various electrical parameters during the test.

[0025] Specifically, the multi-parameter real-time monitoring data includes four core parameters: voltage parameters, current parameters, partial discharge quantity, and waveform distortion index.

[0026] For voltage parameter measurement, this embodiment uses a capacitive voltage divider or an optoelectronic voltage transformer for real-time measurement. The capacitive voltage divider consists of a high-voltage arm capacitor and a low-voltage arm capacitor connected in series. The high-voltage side voltage value is obtained by measuring the voltage across the low-voltage arm capacitor and converting it according to the voltage division ratio. This method has a simple structure, good frequency response characteristics, and is suitable for accurate measurement of power frequency voltage. The optoelectronic voltage transformer is based on the electro-optic effect principle and has advantages such as good insulation performance and strong anti-electromagnetic interference capability, making it suitable for high-precision measurement in complex electromagnetic environments. The voltage parameters specifically include the instantaneous test voltage value, the effective voltage value, and the voltage phase angle. The instantaneous voltage value is used for waveform analysis and distortion rate calculation; the effective voltage value is used for comparison with the test set value; and the voltage phase angle is used in conjunction with the current phase angle to calculate the power factor and determine the resonance state.

[0027] For measuring current parameters, this embodiment uses a current transformer for real-time measurement. The current transformer is installed on the low-voltage side of the test circuit, converting the large current into a small current signal suitable for the measuring device to acquire according to the transformation ratio. The current parameters specifically include the instantaneous value of the test current, the effective value of the current, the current phase angle, and the current harmonic content. The instantaneous value of the current is used for waveform analysis, the effective value of the current is used to determine the state of the test circuit, the current phase angle is used for resonance state monitoring, and the current harmonic content is used to determine whether there are nonlinear factors or signs of fault development in the circuit.

[0028] For monitoring partial discharge, this embodiment employs at least one of the following methods in real time: ultrasonic method, ultra-high frequency method, or pulsed current method. The ultrasonic method uses an ultrasonic sensor mounted on the transformer tank wall to receive the acoustic signals generated by partial discharge, enabling spatial localization of the discharge source. The ultra-high frequency method uses an electromagnetic wave sensor to receive the high-frequency electromagnetic wave signals generated by partial discharge, offering high detection sensitivity and strong anti-interference capabilities. The pulsed current method uses a high-frequency current sensor to detect the discharge pulse current flowing through the grounding wire, showing a good correlation between the signal and the discharge quantity. The specific partial discharge parameters include the apparent value of the discharge quantity and the frequency of discharge pulses per unit time; the former reflects the severity of a single discharge, while the latter reflects the activity level of the discharge.

[0029] Waveform distortion index is obtained by performing Fourier analysis on the collected instantaneous voltage and current data. Specifically, it includes voltage waveform distortion rate and current waveform distortion rate, and is used to determine whether there are abnormal phenomena such as nonlinear distortion or high-frequency oscillation in the test circuit.

[0030] After completing the deployment of the measuring equipment, this step also includes setting monitoring parameter thresholds as the criteria for subsequent fault symptom identification. The specific threshold settings are as follows: the normal fluctuation range of the effective voltage value is ±3% of the set value; when the voltage deviates from this range, it is considered an abnormal voltage. The normal fluctuation threshold of the current is ±5% of the steady-state current value, and the normal value of the total harmonic distortion rate of the current is less than 5%; when it exceeds this range, it is considered an abnormal current. The partial discharge threshold is set to 500pC, and the discharge frequency threshold is set to 10 times / second; when the partial discharge or discharge frequency exceeds 200% of the threshold, it is judged as a sudden increase in partial discharge, indicating that the insulation condition may deteriorate. The normal threshold for voltage waveform distortion rate is 2%, and the normal threshold for current waveform distortion rate is 5%; when the distortion rate exceeds 150% of the normal threshold, it is judged as abnormal waveform distortion.

[0031] S2, based on real-time monitoring data of multiple parameters, uses a multi-parameter comprehensive criterion to classify and identify fault symptoms, and obtain fault symptom types; among them, fault symptom types include: insulation breakdown symptoms, surface flashover symptoms, wiring error symptoms and internal equipment fault symptoms. When the criteria for multiple types of fault symptoms are met at the same time, the judgment is made in the priority order of insulation breakdown, surface flashover, internal equipment fault, and wiring error. This step, based on the multi-parameter real-time monitoring data collected in step S1 and combined with preset judgment rules, comprehensively analyzes and classifies the fault symptoms that may occur during the test. The fault symptom types include four typical types: insulation breakdown symptoms, surface flashover symptoms, wiring error symptoms, and internal equipment fault symptoms.

[0032] Insulation breakdown symptoms refer to the external characteristics exhibited when the internal insulation structure of the tested equipment undergoes a penetrating breakdown. The identification criteria include the following three conditions: First, the effective value of the test current increases by more than 50% of its steady-state value within 100ms, because the low-impedance path formed by insulation breakdown leads to a sharp increase in loop current. Second, the effective value of the test voltage decreases by more than 20% of its set value within 100ms, because the low impedance at the breakdown point shunts the test voltage, resulting in a significant reduction in the voltage applied to the test object. Third, the partial discharge suddenly increases to more than 300% of the reference threshold within 200ms, because severe partial discharge activity usually precedes insulation breakdown. When all three conditions are met, the confidence level of the insulation breakdown symptoms is high. When the first two conditions are met but the third condition is not, the confidence level is medium, which may correspond to a scenario where the breakdown develops extremely rapidly and the partial discharge monitoring system fails to capture it in time. When only the first condition is met, the confidence level is low, requiring further confirmation with other information.

[0033] Surface flashover symptoms refer to discharge phenomena occurring along the surface of insulators or the outer insulation surface of equipment. Typical characteristics include: visible discharge sparks or arcs; intermittent spike pulse characteristics in partial discharge monitoring signals, clearly distinguishable from the continuous discharge characteristics of internal insulation breakdown; high-frequency oscillating components in voltage and current waveforms; and a degree of randomness and recoverability, with the abnormality potentially disappearing after reducing the test voltage.

[0034] Among them, wiring error symptoms refer to abnormal phenomena caused by improper test wiring or loose wiring. Typical characteristics include: abnormalities appearing in the initial stage of voltage increase, with the degree of abnormality proportional to the voltage rise; systematic deviations between measured voltage or current values ​​and expected values; significant deviations of the resonant point from the calculated value; and abnormally high temperatures at the connection points.

[0035] Among them, internal fault symptoms refer to the phenomenon that the insulation of the tested equipment has defects and gradually develops during the test. Its typical characteristics are: the partial discharge shows a slow upward trend with the test time; the partial discharge signal has specific phase distribution characteristics; the abnormal phenomenon begins to appear at a specific voltage level and is repetitive.

[0036] When the criteria for multiple types of fault symptoms are simultaneously met, this method makes a determination in the priority order of insulation breakdown, surface flashover, internal equipment failure, and wiring error. The basis for setting this priority order is as follows: Insulation breakdown belongs to the most serious type of fault, which may cause permanent damage to the equipment and even lead to safety accidents, and thus requires the highest priority for handling; although the harm degree of surface flashover is relatively low, if not dealt with in a timely manner, it may develop into a through-breakdown; internal equipment failures need to be handled carefully to prevent the expansion of defects; wiring errors usually do not cause equipment damage, and the urgency of handling is relatively the lowest. <000010​​​​​​​​​In response to signs of wiring errors, the procedure primarily involves safety checks, including: stopping the voltage boosting operation and maintaining the voltage at the current level or slowly reducing it to a safe level; checking the connection status and tightness of each connection point against the test wiring diagram; checking the polarity and connection location of the voltage and current measurement circuits; verifying the integrity and reliability of the grounding system; and repeating the pre-test inspection procedures after correcting any problems found.

[0041] When dealing with signs of internal equipment malfunctions, the response sequence must balance the continuation of testing with equipment safety protection. Specifically, this includes: reducing the current test voltage to the level before the abnormality occurred and maintaining it stable; continuously monitoring the trend of partial discharge; if the partial discharge shows a decreasing or stable trend, the test can be cautiously continued under enhanced monitoring; if the partial discharge continues to rise or shows an accelerating upward trend, the test should be terminated and a specific diagnosis should be performed; and recording the voltage level where the abnormality occurred, the value of the partial discharge, and its time evolution characteristics to provide a reference for defect nature judgment and maintenance decisions.

[0042] S4 records all monitoring data and event logs throughout the entire experiment and generates an experiment process report based on the recorded data to support diagnostic analysis.

[0043] This step is involved throughout the entire experiment and is responsible for collecting, storing, and generating reports on monitoring data and event information. Complete data records are crucial for fault analysis and liability determination, and also form the data foundation for optimizing judgment thresholds and improving identification accuracy.

[0044] For monitoring data recording, this embodiment sets the following technical requirements: the effective voltage value, effective current value, partial discharge, and waveform distortion rate are recorded at a frequency of not less than once per second, which can meet the needs of trend analysis and condition assessment; the instantaneous waveform data of voltage and current are continuously stored at a sampling frequency of not less than 10 kHz, which can meet the requirements of power frequency waveform analysis and harmonic component analysis not exceeding 2 kHz; the timestamp accuracy of synchronous annotation during data storage is not less than 1 ms, so as to ensure the accuracy of the timing correlation between different channel data and between data and events.

[0045] For event log recording, this embodiment requires the following to be recorded: the start and end times of the test, serving as boundary markers for the test time domain; the voltage setpoints and actual values ​​for each stage, used to reconstruct the test execution process; the fault symptom identification results, their identification time, and confidence level, used to trace the anomaly discovery process; and the triggering time and execution content of the coordinated handling operations, used to evaluate the timeliness of the response and the standardization of the operation.

[0046] Based on the data recorded above, this step is also responsible for generating a test process report. The report includes, but is not limited to: a summary of basic test information, including the test date, test device identification, test personnel, and test standards; test parameter records, including applied voltage values, holding times, and voltage ramp rates at each stage; monitoring curve displays, including trend curves of voltage, current, and partial discharge over time; an event sequence table, listing all events that occurred during the test in chronological order; anomaly analysis, describing and preliminarily analyzing identified fault symptoms; and test conclusions, providing a judgment of pass, fail, or conditionally pass based on the test results.

[0047] In summary, this embodiment overcomes the shortcomings of traditional single-parameter monitoring in terms of insufficient information dimensions by synchronously acquiring multiple parameters such as voltage, current, partial discharge, and waveform distortion indices in real time, providing comprehensive data support for fault symptom identification. By employing multi-parameter comprehensive criteria and setting fault type priority, it effectively improves the accuracy of fault symptom classification and identification, reducing the risk of misjudgment and missed judgment. Triggering corresponding linkage and handling operation sequences based on the identification results realizes automated closed-loop control from fault identification to response and handling, significantly shortening the reaction time of manual intervention. This facilitates timely implementation of protective measures in the early stages of fault development, reducing equipment damage and the risk of test accidents. Simultaneously, through full-process data recording and report generation, it provides a traceable data foundation for fault cause diagnosis and test plan optimization.

[0048] Building upon the technology of the previous embodiment, the following further illustrates, through another specific embodiment, a method for rapid identification of fault symptoms in a converter transformer side external construction frequency resonance test provided in this application.

[0049] This embodiment provides an application scenario description of the method described in Embodiment 1 in an actual converter transformer handover test.

[0050] A newly installed converter transformer at a converter station requires an external construction frequency withstand voltage test on its valve-side winding. The test voltage is set at 380kV, and the holding time is 60 seconds. The test system adopts a series resonant method, consisting of a frequency converter, an excitation transformer, an adjustable reactor, and the valve-side winding of the converter transformer under test, forming a resonant circuit.

[0051] When the voltage was increased to approximately 350kV during the test, the monitoring system recorded the following abnormal data: the effective value of the test current increased from a steady-state value of 1.2A to 1.9A within 80ms, an increase of approximately 58%; the effective value of the test voltage decreased from 350kV to 275kV within the same period, a decrease of approximately 21%; and the partial discharge suddenly increased from a background value of 120pC to 1850pC within 150ms, reaching 370% of the reference threshold of 500pC.

[0052] According to the criterion rules in step S2, if all three conditions are met, the system determines that the fault symptom type is insulation breakdown symptom, and the confidence level is high.

[0053] The system then executes the handling sequence for insulation breakdown symptoms according to step S3: within 15ms after fault symptom identification, a rapid voltage reduction command is triggered, the frequency converter reduces the output frequency at the maximum rate to detune the circuit, and the test voltage drops to 95kV within 420ms, reaching 25% of the set value, meeting the requirement of dropping below 30% within 500ms; then the main circuit of the test power supply is cut off, and the test system enters the shutdown state; on-site personnel wait for 5 minutes of discharge time according to the procedure before entering the test area to conduct safety confirmation and isolation operations.

[0054] By analyzing the test process data recorded in step S4, the fault diagnosis program confirmed that the anomaly was a breakdown of the ground insulation of the valve-side winding of the tested converter transformer. Voltage and current waveform data showed that the breakdown was sudden, and the partial discharge time-series curve showed a slow upward trend starting approximately 2 seconds before the breakdown, indicating that insulation degradation had already begun before the breakdown. These analysis results provided directional guidance for subsequent disassembly inspection and defect location.

[0055] The following describes a rapid fault symptom identification device for a converter transformer side external construction frequency resonance test provided in an embodiment of this application. The rapid fault symptom identification device and the rapid fault symptom identification method for a converter transformer side external construction frequency resonance test described below can be referred to each other.

[0056] Please refer to Figure 2 , Figure 2 This is a schematic diagram of a fault symptom rapid identification device for an external construction frequency resonance test of a converter valve, provided in an embodiment of this application.

[0057] In this embodiment, the device may include: The monitoring data acquisition module 100 is used to synchronously acquire multiple electrical parameters of the test system in real time during the power frequency resonance test to obtain multi-parameter real-time monitoring data; among which, the multi-parameter real-time monitoring data includes voltage parameters, current parameters, partial discharge quantity, and waveform distortion index; The multi-parameter classification module 200 is used to classify and identify fault symptoms based on real-time monitoring data of multiple parameters and using comprehensive criteria of multiple parameters to obtain fault symptom types. Among them, the fault symptom types include: insulation breakdown symptoms, surface flashover symptoms, wiring error symptoms and internal equipment fault symptoms. When the criteria of multiple types of fault symptoms are met at the same time, the judgment is made in the priority order of insulation breakdown, surface flashover, internal equipment fault, and wiring error. The fault linkage handling module 300 is used to trigger the corresponding linkage handling operation sequence according to the fault symptom type; The event logging module 400 is used to fully record monitoring data and event logs throughout the entire test, and generate test process reports based on the recorded data to support diagnostic analysis.

[0058] This application also provides a device for rapid identification of fault symptoms; please refer to it. Figure 3 , Figure 3 This is a schematic diagram of the structure of the fault symptom rapid identification device provided in the embodiments of this application. The fault symptom rapid identification device may include: Memory, used to store computer programs; The processor, when executing a computer program, can implement the steps of a rapid fault symptom identification method for any of the above-described converter valve side external construction frequency resonance tests.

[0059] like Figure 3 The diagram shows the structural composition of a rapid fault symptom identification device. This device may include a processor 10, a memory 11, a communication interface 12, and a communication bus 13. The processor 10, memory 11, and communication interface 12 all communicate with each other via the communication bus 13.

[0060] In this embodiment, the processor 10 may be a central processing unit (CPU), an application-specific integrated circuit, a digital signal processor, a field-programmable gate array, or other programmable logic devices.

[0061] The processor 10 can call the program stored in the memory 11. Specifically, the processor 10 can execute the operations in the embodiment of the abnormal IP identification method.

[0062] The memory 11 is used to store one or more programs. The programs may include program code, which includes computer operation instructions. In this embodiment, the memory 11 stores at least a program for implementing the following functions: S1, during the power frequency resonance test, multiple electrical parameters of the test system are synchronously acquired in real time to obtain multi-parameter real-time monitoring data; among them, the multi-parameter real-time monitoring data includes voltage parameters, current parameters, partial discharge quantity, and waveform distortion index; S2, based on real-time monitoring data of multiple parameters, uses a multi-parameter comprehensive criterion to classify and identify fault symptoms, and obtain fault symptom types; among them, fault symptom types include: insulation breakdown symptoms, surface flashover symptoms, wiring error symptoms and internal equipment fault symptoms. When the criteria for multiple types of fault symptoms are met at the same time, the judgment is made in the priority order of insulation breakdown, surface flashover, internal equipment fault, and wiring error. S3, based on the type of fault symptom, trigger the corresponding linkage and handling operation sequence; S4 records all monitoring data and event logs throughout the entire experiment and generates an experiment process report based on the recorded data to support diagnostic analysis.

[0063] In one possible implementation, the memory 11 may include a program storage area and a data storage area, wherein the program storage area may store the operating system and applications required for at least one function; and the data storage area may store data created during use.

[0064] In addition, memory 11 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device or other volatile solid-state storage device.

[0065] Communication interface 12 can be an interface for the communication module, used to connect with other devices or systems.

[0066] Of course, it should be noted that, Figure 3 The structure shown does not constitute a limitation on the fault symptom rapid identification device in the embodiments of this application. In practical applications, the fault symptom rapid identification device may include more than Figure 3 More or fewer components as shown, or combinations of certain components.

[0067] This application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, can implement the steps of the rapid fault symptom identification method for any of the above-described converter valve side external construction frequency resonance tests.

[0068] The computer-readable storage medium may include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0069] For a description of the computer-readable storage medium provided in this application, please refer to the above method embodiments; further details will not be repeated here.

[0070] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0071] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0072] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0073] The foregoing has provided a detailed description of the rapid fault symptom identification method, device, equipment, and computer-readable storage medium for the external construction frequency resonance test on the converter transformer valve side, as well as the rapid fault symptom identification device and the computer-readable storage medium provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and its core ideas. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A method for quickly identifying fault signs in a valve-side external work frequency resonance test of a converter transformer, characterized by, The method comprises the following steps: S1, during the power frequency resonance test, a plurality of electrical parameters of the test system are collected in real time and synchronously to obtain multi-parameter real-time monitoring data; wherein the multi-parameter real-time monitoring data comprises voltage parameters, current parameters, partial discharge quantity, and waveform distortion index; S2, based on the multi-parameter real-time monitoring data, a multi-parameter comprehensive criterion is used to classify and identify fault signs to obtain fault sign types; wherein the fault sign types comprise insulation breakdown signs, surface flashover signs, wiring error signs, and device internal fault signs; when the criteria of multiple fault signs are met simultaneously, the insulation breakdown, surface flashover, device internal fault, and wiring error are determined according to the priority order; S3, according to the fault sign types, a corresponding linkage disposal operation sequence is triggered; S4, during the whole test process, the monitoring data and event logs are recorded completely, and a test process report is generated based on the recorded data to support diagnostic analysis.

2. The method of claim 1, wherein In the S1, the voltage parameters are measured in real time by using a capacitor voltage divider or an optoelectronic voltage transformer, including test voltage instantaneous value, voltage effective value, and voltage phase angle; The current parameters are measured in real time by using a current transformer, including test current instantaneous value, current effective value, current phase angle, and current harmonic content; The partial discharge quantity is monitored in real time by using at least one of an ultrasonic method, an ultrahigh frequency method, or a pulse current method, including discharge quantity apparent value and discharge pulse frequency per unit time.

3. The method of claim 2, wherein The S1 further comprises setting monitoring parameter threshold values; wherein the monitoring parameter threshold values comprise that the normal fluctuation range of the voltage effective value is ±3% of the set value; the current normal fluctuation threshold value is ±5% of the steady-state current value, and the total harmonic distortion rate of the current normal value is less than 5%; the partial discharge quantity reference threshold value is 500 pC, and the discharge frequency reference threshold value is 10 times per second; when the partial discharge quantity or the discharge frequency exceeds 200% of the reference threshold value, it is determined that the partial discharge quantity or the discharge frequency is suddenly increased; the voltage waveform distortion rate normal threshold value is 2%, and the current waveform distortion rate normal threshold value is 5%; when the distortion rate exceeds 150% of the normal threshold value, it is determined that the waveform is abnormally distorted.

4. The method of claim 3, wherein In the S2, the identification criterion of the insulation breakdown sign comprises the following three conditions: the test current effective value rises by more than 50% of the steady-state value within 100 ms, the test voltage effective value drops by more than 20% of the set value within 100 ms, and the partial discharge quantity suddenly increases to more than 300% of the reference threshold value within 200 ms; when all the three conditions are met, the confidence level is high; when the first two conditions are met but the third condition is not met, the confidence level is medium; and when only the first condition is met, the confidence level is low.

5. The method of claim 4, wherein In the S3, the disposal sequence for the insulation breakdown sign comprises: triggering a rapid voltage reduction instruction to control the voltage regulator to reduce the voltage at the maximum rate, reducing the test voltage to less than 30% of the set value within 500 ms; after the voltage is reduced to a safe level, the test power main circuit is cut off to execute emergency shutdown; after the test sample discharges for not less than 5 minutes, on-site isolation and safety confirmation are performed; the fault diagnosis program is started and the recorded data in the S4 are called to perform analysis.

6. The method of claim 5, wherein The treatment sequence for surface flashover signs in S3 includes triggering a fast voltage reduction instruction, reducing the test voltage to less than 50% of the set value within 1 second; maintaining the low voltage state for 10 seconds to confirm whether the abnormal phenomenon disappears; if the abnormality disappears, the voltage is increased to 80% of the original test voltage at a rate not exceeding 50% of the rated voltage increase rate for verification, if the abnormality reappears, shutdown and isolation inspection are performed, and the isolation inspection includes checking the surface state of the insulator, checking the safety distance of the lead and the grounding body, and checking whether there is foreign matter or contamination.

7. The method of claim 6, wherein In S4, the monitoring data is recorded at a frequency of not less than 1 time per second, and the values of voltage effective value, current effective value, partial discharge amount and waveform distortion rate are recorded. The instantaneous waveform data of voltage and current are continuously stored at a sampling frequency of not less than 10 kHz, and the data storage is synchronized with the time stamp with an accuracy of not less than 1 ms; the event log record includes the test start and end time, the voltage set value and actual value of each stage, the fault sign identification result and its identification time and confidence, and the trigger time and execution content of the linkage treatment operation.

8. A device for quickly identifying failure signs in a valve-side external work frequency resonance test of a converter transformer, characterized by Comprise: A monitoring data acquisition module for real-time synchronous acquisition of a plurality of electrical parameters of a test system during a power frequency resonance test to obtain multi-parameter real-time monitoring data; wherein the multi-parameter real-time monitoring data includes voltage parameters, current parameters, partial discharge amount, and waveform distortion indicators; A multi-parameter classification module for classifying and identifying fault signs based on the multi-parameter real-time monitoring data using a multi-parameter comprehensive criterion to obtain fault sign types; wherein the fault sign types include insulation breakdown signs, surface flashover signs, wiring error signs, and internal device fault signs, and when the criteria of multiple fault signs are met simultaneously, the priority order of insulation breakdown, surface flashover, internal device fault, and wiring error is determined; A fault linkage treatment module for triggering corresponding linkage treatment operation sequences according to the fault sign types; An event recording module for recording monitoring data and event logs throughout the test process, and generating a test process report based on the recorded data to support diagnostic analysis.

9. A failure symptom quick identification device characterized by comprising: Comprise: A memory for storing a computer program; A processor for executing the computer program to implement the steps of the fault sign rapid identification method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the steps of the fault sign rapid identification method according to any one of claims 1 to 7.

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