A transformer arc fault equivalent test device and control method

Abstract

The application discloses a transformer arc fault equivalent test device and a control method, relates to the technical field of power equipment fault simulation and safety test, and comprises the following steps: corresponding high-pressure gas storage is carried out by a high-pressure gas storage unit according to target pressure data calculated by a choked flow dynamic coupling model; a quick release unit releases the high-pressure gas stored in the high-pressure gas storage unit according to a test trigger instruction matched with a fault duration; an energy injection unit injects the high-pressure gas into a test oil tank to form a shock wave; a safety protection unit starts an interlocking protection mechanism based on test data; a monitoring control unit controls the actions of each unit, monitors the operation process of each unit in real time, acquires and identifies the validity of test data, and optimizes the test process; the application realizes automatic test process control, can accurately quantify and reproduce the key damage effect of an arc fault, realizes high-precision matching of the time-domain characteristics of a pressure wave, and ensures the reliability of test results.

Description

Technical Field

[0001] This application relates to the field of power equipment fault simulation and safety testing technology, specifically to a transformer arc fault equivalent test device and control method. Background Technology

[0002] Distribution transformers are prone to internal arcing faults during operation. The enormous energy released instantaneously can cause the oil tank to rupture, seriously threatening the safety of the power grid. Currently, simulation studies of this fault in the field have the following shortcomings: First, real arcing discharge tests are extremely dangerous, costly, and have poor repeatability, and are difficult to conduct in ordinary laboratories; second, simplified alternative methods (such as ordinary gas release or chemical explosion) have significantly different energy release timing characteristics, pressure waveforms, and spatial distribution compared to real arcing faults, making accurate and comparable equivalent simulations impossible.

[0003] Specifically, at the device level: existing pneumatic components or explosion simulation devices, due to the lack of an integrated test platform that combines high-pressure gas storage, millisecond-level rapid release, multiple interface energy injection, and multiple safety protections, cannot meet the stringent requirements for high-fidelity reproduction of the transient process of arc faults. At the methodological level: the lack of suitable systematic processes and control methods makes it difficult to convert arc fault parameters into device control commands, thereby failing to achieve a complete closed loop from parameter reverse design, safety interlocking, precise process execution to result self-verification and system self-optimization.

[0004] In summary, existing technologies for studying transformer arc fault mechanisms and verifying explosion-proof measures suffer from low accuracy and poor reliability of experimental data due to limitations in device configuration and poor adaptability.

[0005] The patent "Simulation Test Method and Platform for Explosive Combustion of UHV Converter Transformer Grid-Side Bushing Faults," publication number CN120294518A, discloses a method based on an arc energy fault model. By setting different simulated fault arc energy conditions, it calculates the arc energy value under short-circuit conditions in the riser seat of an UHV converter transformer grid-side bushing, and uses this to determine the critical energy thresholds for primary physical explosions and secondary chemical explosions, thereby obtaining the critical triggering conditions for bushing fault explosive combustion. The arc energy fault model includes: setting test groups under different voltages, simulating arc discharge tests inside the riser seat, connecting the fault arc energy test circuit and the simulated UHV converter transformer grid-side bushing platform according to the required simulated test voltage and current values, first adjusting the discharge gap in the simulated UHV converter transformer grid-side bushing platform to its maximum, and then gradually reducing the discharge gap, conducting tests sequentially according to the test groups. However, the core control link for arc ignition in this scheme is adjusting the discharge gap. The success rate of arc ignition and energy stability are greatly affected by human factors, and it relies on large-scale high-power equipment clusters, making it unsuitable for ordinary laboratories, resulting in poor applicability. Summary of the Invention

[0006] The purpose of this application is to address the problem of low accuracy and reliability of test data caused by the low adaptability of existing transformer arc fault testing technology. It proposes an equivalent test device and control method for transformer arc faults. By using a congestion flow dynamic coupling model, the key destructive effect (mechanical energy impact) of arc faults is accurately quantified and reproduced, achieving high-precision matching of the time-domain characteristics of pressure waves. The coordinated operation of each unit avoids the uncertainty of manual parameter adjustment, ensuring the reliability of test results and improving the accuracy of test data.

[0007] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0008] In a first aspect, embodiments of this application provide a transformer arc fault equivalent test apparatus, the apparatus comprising:

[0009] The high-pressure gas storage unit stores high-pressure gas based on the target pressure data calculated by the choke flow dynamic coupling model.

[0010] The rapid release unit releases the high-pressure gas stored in the high-pressure gas storage unit by matching the fault duration according to the test trigger command;

[0011] The energy injection unit injects high-pressure gas into the test tank to create a shock wave;

[0012] The safety protection unit activates the interlocking protection mechanism based on test data;

[0013] The monitoring and control unit controls the actions of each unit and monitors the operation process of each unit in real time, acquiring and identifying the validity of test data to optimize the test process.

[0014] In this scheme, the mechanical energy required for the test is stored in a high-pressure gas storage unit, providing quantifiable mechanical energy for subsequent energy release. This ensures that the output energy matches the target fault and avoids distortion of the impact waveform caused by unstable energy input. A rapid release unit precisely controls the timing of the high-pressure gas to be released, ensuring that the gas release time perfectly matches the duration of the actual arc fault. This avoids timing deviations that could cause the impact process to be out of sync with the actual fault, ensuring that the energy injection unit injects the high-pressure gas into the target fault location of the test tank on time, reducing simulation errors in the pressure rise rate, and ensuring that the impact direction is consistent with the actual arc fault. A safety protection unit triggers overpressure protection, emergency shutdown and isolation, and abnormal monitoring and early warning during the test process, ensuring safety throughout the entire test cycle and guaranteeing the smooth progress of the test. A monitoring and control unit collects real-time operating data from the test tank to coordinate the synchronous operation of each unit, thereby achieving fully automated control of the entire process, reducing manual intervention, optimizing the test process, further improving test efficiency, and ensuring the accuracy and reliability of the test results.

[0015] Preferably, the high-pressure gas storage unit includes:

[0016] The pressure calculation subunit calculates the mechanical energy required for the test based on the characteristics of the arc fault, according to the dynamic coupling model of the congested flow. Based on the mechanical energy, the fault time parameters, and the structural information of the gas transmission pipeline in the test device, the target pressure data is calculated.

[0017] The inflation component inflates the air tank using the target pressure data as the inflation reference, and collects the pressure data inside the air tank in real time.

[0018] The pressure monitoring component determines the inflation status based on the pressure data inside the gas tank and dynamically adjusts the two-stage pressure reducing valve to control the pressure balance of the gas tank.

[0019] Preferably, the rapid release unit includes:

[0020] The status of the valve control mechanism and the status of the parallel-configured pipeline are verified according to the first self-test command sent by the monitoring and control unit.

[0021] Based on the test trigger command and the duration of the fault, the valve control mechanism is controlled to open and close, thereby releasing the high-pressure gas.

[0022] Preferably, the energy injection unit includes:

[0023] Determine the target interface of the test tank based on the target fault location information;

[0024] Based on the opening control of the valve control mechanism by the rapid release unit, the released high-pressure gas is directed to the test oil tank through the target interface to form a shock wave that matches a real electric arc fault.

[0025] Preferably, the test tank verifies the safety status of the tank based on the second self-test command sent by the monitoring and control unit, generates mechanical energy of a real electric arc fault based on the high-pressure gas injected by the energy injection unit based on the safety verification result, and records the tank vibration data during the mechanical energy impact process.

[0026] Preferably, the safety protection unit triggers the interlocking protection action of each unit based on the abnormal test state.

[0027] Preferably, the monitoring and control unit includes:

[0028] The monitoring subunit generates corresponding control commands based on the test process to control the actions of each unit and monitor the operation process of each unit in real time.

[0029] The data acquisition subunit collects pressure and temperature data from the test tank in real time and calculates waveform consistency to identify the validity of the test data and establish waveform mapping relationships.

[0030] The process optimization subunit corrects the parameters of the congestion flow dynamic coupling model based on the identified test data and waveform mapping relationship in order to optimize the test process.

[0031] Preferably, the real-time acquisition of pressure and temperature data from the test tank, and the calculation of waveform consistency to identify the validity of the test data and to label the data type, includes:

[0032] Pressure characteristics are obtained based on historical fault data, and a target waveform curve is established based on the pressure characteristics.

[0033] Based on the test pressure curve in the test tank and the target waveform curve, the optimal path distance between the curves is calculated using a dynamic time warping algorithm.

[0034] The optimal path distance is normalized to obtain the waveform matching degree, and the waveform matching degree is compared with the target threshold. If the waveform matching degree is greater than or equal to the target threshold, the experiment is determined to be valid and the experiment data is marked as valid experiment data; if the waveform matching degree is less than the target threshold, the experiment is determined to be invalid and the experiment data is marked as invalid experiment data.

[0035] The waveform mapping relationship is obtained based on the test data with the corresponding test pressure curve.

[0036] Preferably, the test data based on the identifier, combined with waveform mapping relationships, is used to correct the parameters of the choking flow dynamic coupling model to optimize the test process, including:

[0037] Based on the waveform mapping relationship, the valid test data and the invalid test data are preprocessed to determine the benchmark sample and supplementary sample for parameter correction;

[0038] Weights are assigned to the baseline sample and the supplementary sample respectively. The weighted samples are iteratively calculated using the recursive least squares method according to the congestion flow dynamic coupling model until the deviation between the waveform fit and the target threshold is minimized, thereby obtaining the optimal parameters of the congestion flow dynamic coupling model.

[0039] Based on the optimal parameters, the optimized target pressure data is obtained, thereby enabling the adjustment and optimization of the test procedure.

[0040] Secondly, embodiments of this application provide a control method for a transformer arc fault equivalent test device, including:

[0041] High-pressure gas storage is performed based on the target pressure data calculated using the choke flow dynamic coupling model.

[0042] The high-pressure gas stored in the high-pressure gas storage unit is released according to the fault duration matched by the test trigger command.

[0043] High-pressure gas is injected into the test tank to form a shock wave, and the interlock protection mechanism is activated based on the test data;

[0044] The operation process of each unit is monitored in real time, and the validity of the test data is identified to optimize the initial parameters of the choke flow dynamic coupling model, thereby optimizing the test control process of the test device.

[0045] The beneficial effects of this application are:

[0046] 1. The key destructive effect (mechanical energy impact) of arc faults was accurately quantified and reproduced by the dynamic coupling model of congested flow. In particular, by controlling the release time, high-precision matching of the time domain characteristics of pressure waves was achieved, avoiding the distortion of the impact waveform caused by unstable energy input.

[0047] 2. By precisely controlling the timing of the high-pressure gas to be released, the gas release time is ensured to be completely matched with the duration of the actual arc fault, avoiding timing deviations that cause the impact process to be out of sync with the actual fault, reducing the simulation error of the pressure rise rate, and thus ensuring that the energy injection unit injects the high-pressure gas into the target fault location of the test tank on time, ensuring that the impact direction is consistent with the actual arc fault.

[0048] 3. Through system self-checking and safety interlock protection, potential faults can be identified in the early stages of the test process, and abnormal protection can be provided throughout the entire test process to ensure the safety of personnel and equipment during the test, while ensuring the smooth progress of the test;

[0049] 4. The dynamic coupling model of congested flow is optimized by using experimental data to achieve a closed loop of experiment, optimization and re-experiment, which reduces the parameter error of the initialization of the experiment, improves the automation level of the process and the waveform consistency, thereby improving the experimental efficiency and ensuring the accuracy and reliability of the experimental results. Attached Figure Description

[0050] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. The drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings;

[0051] Figure 1 A schematic diagram of a transformer arc fault equivalent test device unit provided in this application embodiment;

[0052] Figure 2 A schematic diagram of a transformer arc fault equivalent test device provided in this application embodiment;

[0053] Figure 3 A flowchart illustrating the control method of a transformer arc fault equivalent test device provided in this application embodiment. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description of this application is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely one preferred embodiment of this application and are only used to explain this application. They do not limit the scope of protection of this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0055] Example 1: As Figure 1 As shown, a transformer arc fault equivalent test device includes:

[0056] The high-pressure gas storage unit stores high-pressure gas based on the target pressure data calculated by the choke flow dynamic coupling model.

[0057] The rapid release unit releases the high-pressure gas stored in the high-pressure gas storage unit by matching the fault duration according to the test trigger command;

[0058] The energy injection unit injects high-pressure gas into the test tank to create a shock wave;

[0059] The safety protection unit activates the interlocking protection mechanism based on test data;

[0060] The monitoring and control unit controls the actions of each unit and monitors the operation process of each unit in real time, acquiring and identifying the validity of test data to optimize the test process.

[0061] In this embodiment, the mechanical energy required for the test is stored in a high-pressure gas storage unit, providing quantifiable mechanical energy for subsequent energy release. This ensures that the output energy matches the target fault, avoiding distortion of the impact waveform caused by unstable energy input. A rapid release unit precisely controls the timing of the high-pressure gas to be released, ensuring that the gas release time perfectly matches the duration of the actual arc fault. This avoids timing deviations that could cause the impact process to be out of sync with the actual fault, thus ensuring that the energy injection unit injects the high-pressure gas into the target fault location of the test tank on time, reducing the simulation error of the pressure rise rate and ensuring that the impact direction is consistent with the actual arc fault. A safety protection unit triggers overpressure protection, emergency shutdown and isolation, and abnormal monitoring and early warning during the test process, ensuring safety throughout the entire test cycle and guaranteeing the smooth progress of the test. A monitoring and control unit coordinates the synchronous operation of each unit, thereby achieving fully automated control of the entire process, reducing manual intervention, optimizing the test process, further improving test efficiency, and ensuring the accuracy and reliability of the test results.

[0062] As an optional implementation, the high-pressure gas storage unit includes:

[0063] The pressure calculation subunit calculates the mechanical energy required for the test based on the characteristics of the arc fault, according to the dynamic coupling model of the congested flow. Based on the mechanical energy, the fault time parameters, and the structural information of the gas transmission pipeline in the test device, the target pressure data is calculated.

[0064] The inflation component inflates the air tank using the target pressure data as the inflation reference, and collects the pressure data inside the air tank in real time.

[0065] The pressure monitoring component determines the inflation status based on the pressure data inside the gas tank and dynamically adjusts the two-stage pressure reducing valve to control the pressure balance of the gas tank.

[0066] In some embodiments, the gas storage tank is a steel gas tank with a volume of 200L~1000L and a pressure rating of 0.1~20MPa (e.g., Figure 2 As shown, high-pressure gas is quantitatively stored according to the mechanical energy required for the experiment, providing quantifiable mechanical energy for subsequent energy release. The pressure monitoring component stabilizes the gas tank pressure at the calculated initial target pressure (i.e., target pressure data) through closed-loop regulation of a two-stage pressure reducing valve and a pressure sensor, ensuring that the output energy matches the target fault.

[0067] Specifically, the choke flow dynamic coupling model refers to the choke flow dynamic coupling function. Based on the total energy and duration of the target arc fault, and using a preset energy component equivalent model, the mechanical energy required for the experiment is calculated. Then, combined with the fault duration and pipeline structural parameters, the initial target pressure (i.e., target pressure data) of the gas storage tank is obtained by inverse calculation using the choke flow dynamic coupling function.

[0068] Furthermore, the energy component equivalent model is expressed as:

[0069] E = k× ;

[0070] Where E represents the mechanical energy required to be simulated in the experiment. The value of k represents the total energy of the target arc fault. k is the mechanical energy conversion coefficient determined through a large amount of experimental data. For oil-immersed distribution transformers, the value of k can be 22% to 26%, with an optimal value of 24%.

[0071] It should be noted that the mechanical energy generated by the transformer arc fault accounts for 24% of the total fault energy. Therefore, the test device only needs to output mechanical energy equivalent to 24% of the total arc energy. After determining the required energy, the required throttling flow rate is calculated based on parameters such as the effective pipe area and fault time. ,Right now:

[0072] ;

[0073] in, The duration of the fault.

[0074] Furthermore, the required flow rate is calculated based on the required throttling flow rate. The calculation formula is as follows:

[0075] ;

[0076] in, Indicates the air insulation index. Represents internal energy per unit mass;

[0077] The dynamic coupling function for congested flow is expressed as follows:

[0078] ;

[0079] in, R represents the flow coefficient, and R represents the air constant. Indicates temperature. Represents the cross-sectional area of ​​the pipe. Indicates target pressure;

[0080] When initializing the target pressure, the target pressure data is calculated by substituting the required flow velocity and other parameter values ​​into the above-mentioned choke flow dynamic coupling function.

[0081] In some embodiments, the pressure monitoring component can be integrated separately into the piezoelectric pressure sensor and deployed at the bottom of the gas tank, or integrated into the sensor component of the safety protection unit. It is used to collect the actual pressure inside the gas tank in real time and feed back the pressure data to the monitoring and control unit according to the time period. If the deviation between the actual pressure and the target pressure data exceeds the preset pressure threshold, such as 0.05MPa, the monitoring and control unit generates a fine-tuning command for replenishing or depressurizing. The pressure is adjusted through a two-stage pressure reducing valve until the pressure stabilizes within the standard range. After the inflation is completed, the pressure monitoring component generates an inflation completion signal and sends it to the monitoring and control unit, which then issues the next process command to advance the test process.

[0082] As an optional implementation, the quick release unit includes:

[0083] The status of the valve control mechanism and the status of the parallel-configured pipeline are verified according to the first self-test command sent by the monitoring and control unit.

[0084] Based on the test trigger command and the duration of the fault, the valve control mechanism is controlled to open and close, thereby releasing the high-pressure gas.

[0085] In some embodiments, the rapid release unit further includes a flow monitoring component integrated into a mass flow meter for real-time acquisition of flow data, which is then sent to the monitoring and control unit according to a time period. Specifically, after the high-pressure gas storage unit completes its filling, the monitoring and control unit sends a first self-test command to the rapid release unit. The rapid release unit verifies the valve communication status, open / closed status, and pipeline sealing (e.g., no leakage at 2MPa pressure), and feeds back the self-test result (normal / abnormal) to the monitoring and control unit. If the self-test is normal, the unit enters a valve standby state. Upon receiving a test trigger command, it controls both valves to open synchronously within a time period (e.g., 0.02ms). The initial opening degree is set according to the target flow rate. When the real-time acquired flow data deviates from the target flow rate by more than a preset threshold, the opening degree is adjusted. After the gas release is completed, the valve closes and sends a release completion signal to the monitoring and control unit, which then issues the next process command to advance the test process.

[0086] In some embodiments, the valve control mechanism includes two parallel pipelines and a high-speed solenoid valve / pneumatic valve to open and release gas within milliseconds, thereby accelerating the test process and improving test efficiency.

[0087] As an optional implementation, the energy injection unit includes:

[0088] Determine the target interface of the test tank based on the target fault location information;

[0089] Based on the opening control of the valve control mechanism by the rapid release unit, the released high-pressure gas is directed to the test oil tank through the target interface to form a shock wave that matches a real electric arc fault.

[0090] In this embodiment, the input end of the energy injection unit is connected to the output end of the rapid release unit via a pipe, and the output end of the energy injection unit is connected to the input interface of the simulated transformer tank (i.e., the test tank) via a pipe. The energy injection unit serves as the energy transmission channel for the test, rapidly injecting the high-pressure gas released by the rapid release unit into the test tank. This ensures the gas is injected directionally into the target fault location, forming a shock wave that matches a real arc fault and reducing pressure loss.

[0091] In some embodiments, before the energy injection unit injects high-pressure gas into the test tank, it further includes: verifying the sealing performance of the flow channel (pipeline), pressure sensor communication and zero-point drift according to the self-test command of the monitoring and control unit, and feeding back the self-test result to the monitoring and control unit. If the self-test is abnormal, the gas injection is stopped. When the self-test result is normal, the gas flows to the target fault location of the test tank and the dynamic pressure data in the middle of the flow channel is collected in real time to determine whether the pressure loss exceeds the allowable range. If an abnormal pressure is detected, the pressure is immediately fed back to the monitoring and control unit, an early warning is issued and corresponding operation and maintenance actions are initiated.

[0092] As an optional implementation, the test tank verifies the safety status of the tank based on the second self-test command sent by the monitoring and control unit. Based on the safety verification result, the test tank generates mechanical energy of a real electric arc fault according to the high-pressure gas injected by the energy injection unit, and records the tank vibration data during the mechanical energy impact process.

[0093] In this embodiment, the test tank serves as the core carrier for fault simulation, simulating the structure of a real transformer tank and typical arc fault locations, and withstanding high-voltage gas shock waves. The test tank includes multiple quick-connect interfaces distributed on the side wall, top, and bottom of the tank, corresponding to typical arc fault locations such as bushing roots and lead joints, to enable rapid switching between different test locations, thereby ensuring the realism of the simulated scenario.

[0094] As an optional implementation, the safety protection unit triggers the interlocking protection action of each unit based on the abnormal test state.

[0095] Specifically, the safety protection unit includes at least an overpressure protection component, an emergency stop component, a physical isolation barrier, and a monitoring and early warning component; the overpressure protection component includes a pressure relief valve and an explosion-proof plate, the emergency stop component includes a dual-channel emergency stop switch and a pressure relief channel, the physical isolation barrier includes tempered laminated glass and a protective railing, and the monitoring and early warning component includes a gas leak sensor or an infrared thermal imager.

[0096] In some embodiments, when the monitoring and control module detects abnormal pressure and / or temperature data in the gas storage tank or test oil tank, it generates a safety interlock protection command and sends it to the safety protection unit. The safety protection unit activates the open states of each component to ensure the safety of the test process. For example, when the test oil tank pressure reaches 22 MPa, the pressure relief valve automatically opens, reducing the pressure to 20 MPa before closing; if the pressure reaches 25 MPa, the explosion-proof diaphragm automatically ruptures, simultaneously opening the pressure relief channel; if gas leakage or equipment overheating is detected, an audible and visual alarm is triggered.

[0097] As an optional implementation, the monitoring and control unit includes:

[0098] The monitoring subunit generates corresponding control commands based on the test process to control the actions of each unit and monitor the operation process of each unit in real time.

[0099] The data acquisition subunit collects pressure and temperature data from the test tank in real time and calculates waveform consistency to identify the validity of the test data and establish waveform mapping relationships.

[0100] The process optimization subunit corrects the parameters of the congestion flow dynamic coupling model based on the identified test data and waveform mapping relationship in order to optimize the test process.

[0101] In some embodiments, such as Figure 2 As shown, the monitoring subunit is used to issue self-test commands to the high-pressure gas storage unit, rapid release unit, energy injection unit, test oil tank, and safety protection unit, and to receive self-test data from each unit, and to determine whether there is any abnormality; if any unit is abnormal, an audible and visual alarm is triggered and the process is interrupted.

[0102] Furthermore, a pressure-time curve is established based on the collected data. The normalized root mean square error (RMSE) of the measured waveform and the target waveform in terms of peak pressure, pressure rise rate, and duration is calculated using a dynamic time warping algorithm, thereby quantifying the waveform consistency. If the consistency is greater than or equal to the target threshold, the pressure data is deemed valid. A mapping relationship between the test parameters and the output waveform is constructed by integrating the input parameters (including target pressure data and fault duration) and output data (pressure waveform, waveform consistency) from multiple tests. The key parameters of the choking flow dynamic coupling function (including throttling flow coefficient, air adiabatic index, and pipe cross-sectional area) are adaptively corrected using the recursive least squares method. The target pressure is recalculated based on the corrected parameters, improving test accuracy, providing waveform consistency, ensuring test reliability while reducing test errors, and improving test efficiency.

[0103] As an optional implementation, the real-time acquisition of pressure and temperature data from the test tank, and the calculation of waveform consistency to identify the validity of the test data and to label the data type, includes:

[0104] Pressure characteristics are obtained based on historical fault data, and a target waveform curve is established based on the pressure characteristics.

[0105] Based on the test pressure curve in the test tank and the target waveform curve, the optimal path distance between the curves is calculated using a dynamic time warping algorithm.

[0106] The optimal path distance is normalized to obtain the waveform matching degree, and the waveform matching degree is compared with the target threshold. If the waveform matching degree is greater than or equal to the target threshold, the experiment is determined to be valid and the experiment data is marked as valid experiment data; if the waveform matching degree is less than the target threshold, the experiment is determined to be invalid and the experiment data is marked as invalid experiment data.

[0107] The waveform mapping relationship is obtained based on the test data with the corresponding test pressure curve.

[0108] Specifically, based on historical fault data, three dimensions of characteristics are extracted: the peak pressure representing the maximum impact intensity of the simulated arc fault, the rate of pressure rise representing the temporal characteristics of the simulated fault energy release, and the fault duration, to establish a target waveform curve. For example, the target waveform for an arc fault in an oil-immersed distribution transformer can be set as follows: peak pressure 2.5 MPa, rise time 5 ms, duration 20 ms, with the pressure curve exhibiting an exponential shape of rapid rise and slow fall.

[0109] Furthermore, the experimentally measured pressure curve and the target waveform curve are processed into time series of equal length or alignable, and the pressure values ​​are mapped to the [0,1] interval to eliminate dimensional differences and ensure numerical scale comparability. A distance matrix D is constructed based on the time series corresponding to the experimentally measured pressure curve and the target waveform curve, where each element represents the Euclidean distance between a position in the measured pressure sequence and a position in the target waveform sequence.

[0110] Dynamic programming is used to find the optimal path from the top left corner to the bottom right corner of the distance matrix D, minimizing the sum of distances along the path. The total distance of the optimal path is then obtained and normalized to calculate the waveform matching degree (the smaller the value, the higher the matching degree). When the waveform matching degree is greater than or equal to the target threshold, the measured pressure waveform is deemed to have "met the equivalence standard" with the target waveform. The compliant test data are marked as valid data, which includes the input parameters (total energy of the target arc fault). Fault duration Target pressure of the gas storage tank ) and output waveform (peak pressure, pressure rise rate, duration).

[0111] In some embodiments, establishing a waveform mapping relationship includes: combining the identified data with the actual pressure data of the gas storage tank, the flow coefficient, and the air adiabatic index to establish a one-to-one correspondence between the input parameters of the choke flow dynamic coupling model and the output waveform of the device, thereby obtaining the waveform mapping relationship.

[0112] In other embodiments, establishing the waveform mapping relationship further includes: combining the identified data with the actual pressure data of the gas storage tank, the throttling flow rate, the air adiabatic index, the waveform fit, and the deviation type between the waveform fit and the target threshold to establish a waveform mapping relationship that includes the correspondence between the input parameters of the choke flow dynamic coupling model and the deviation. For example, the choke flow dynamic coupling function calculates the target pressure data. The one-to-one correspondence between the flow coefficient corresponding to the flow rate, the deviation of the peak pressure corresponding to the flow coefficient, and the other three.

[0113] The deviation type of waveform matching between the target threshold and the actual test pressure waveform corresponds to the deviation type between the measured pressure waveform and the target pressure waveform. This includes deviations caused by peak pressure (identified as the first deviation type), deviations caused by the rate of pressure rise (identified as the second deviation type), and deviations caused by duration (identified as the third deviation type). For example, if the peak pressure is insufficient, the first deviation type indicates insufficient peak pressure.

[0114] In some examples, simulating a 100ms arc fault in a 10kV transformer, the valid experimental data (corresponding to a waveform consistency of 92%) includes the following waveform mapping relationship: the total energy of the target arc fault. Fault duration Target pressure of the gas storage tank The actual pressure stored in the gas storage tank Flow coefficient Peak pressure measured in experiments (The peak pressure of the target pressure curve is 2.4 MPa), and the deviation of the waveform fit is -4.2%; if the flow coefficient in the invalid test data... Peak pressure measured in experiments If the deviation is -16.7%, the deviation type should be marked as the first deviation type, which means insufficient peak pressure.

[0115] As an optional implementation, the identification-based experimental data, combined with waveform mapping relationships, is used to correct the parameters of the choking flow dynamic coupling model to optimize the experimental process, including:

[0116] Based on the waveform mapping relationship, the valid test data and the invalid test data are preprocessed to determine the benchmark sample and supplementary sample for parameter correction;

[0117] Weights are assigned to the baseline sample and the supplementary sample respectively. The weighted samples are iteratively calculated using the recursive least squares method according to the congestion flow dynamic coupling model until the deviation between the waveform fit and the target threshold is minimized, thereby obtaining the optimal parameters of the congestion flow dynamic coupling model.

[0118] Based on the optimal parameters, the optimized target pressure data is obtained, thereby enabling the adjustment and optimization of the test procedure.

[0119] It should be noted that when there is a deviation between the measured pressure waveform and the target waveform, it can be attributed to the deviation of the flow coefficient, air adiabatic index, or pipe cross-sectional area in the parameters of the choked flow dynamic coupling model. Therefore, a linear relationship between the peak pressure and the flow coefficient, air adiabatic index, or pipe cross-sectional area can be established. Based on the effective / ineffective test data as samples, the input parameters of the choked flow dynamic coupling model can be adaptively corrected using the recursive least squares method.

[0120] Specifically, based on the choke flow dynamic coupling function, and using the initial flow coefficient and air adiabatic index as benchmarks, the mechanical energy E and fault duration from the effective experimental data are substituted. Calculate target pressure data In addition, the standard flow rate (i.e. the ideal rate at which high-pressure gas is released from the storage tank through the pipeline) is compared with the experimentally measured flow rate (the relationship between the test tank volume and the pressure-flow rate is obtained by inverting the experimentally measured peak pressure) to obtain the flow coefficient deviation, air adiabatic index deviation, and pipeline cross-sectional area deviation, and then obtain the flow coefficient correction, air adiabatic index correction, and pipeline cross-sectional area correction.

[0121] Among them, standard flow The calculation formula is as follows:

[0122] ;

[0123] Among them, the flow coefficient This reflects the flow resistance characteristics of the valve / pipeline; the greater the flow resistance, the better. The smaller, The smaller the value; the lower the air insulation index. Reflects the energy transfer efficiency during gas expansion. The smaller the value, the slower the gas expands and the more gradual the pressure rise. Reflects gas flow capacity The smaller, The smaller the value, the lower the peak pressure.

[0124] Furthermore, high weights are assigned to the baseline samples corresponding to valid test data, and low weights are assigned to the supplementary samples corresponding to invalid test data. The flow coefficient and air adiabatic index are updated through a recursive formula.

[0125] In other embodiments, updating the parameters further includes: constructing an objective function with the goal of minimizing the deviation between the measured pressure curve characteristics and the target waveform curve; and obtaining the optimal parameter set through iterative solution. The objective function is shown below:

[0126] ;

[0127] ;

[0128] ;

[0129] ;

[0130] in, Represent the objective function; , , These are weighting coefficients, set according to the importance of waveform curve characteristics based on experimental requirements (e.g., ); Peak deviation rate, characterizing the deviation between the flow coefficient and the peak pressure; Rise time deviation rate, characterizing the deviation between the air adiabatic index and the pressure rise rate; The decay time deviation rate characterizes the deviation between the pipe cross-sectional area and the peak pressure.

[0131] It should be noted that, based on the corrected flow coefficient, air adiabatic index, and pipe cross-sectional area, new test parameters are calculated. The test procedure is then executed based on the calculated target pressure data. If the measured pressure waveform shows a higher degree of agreement than the original target threshold, the parameter correction is considered effective. Finally, the verified parameters are used as the optimal parameters to optimize subsequent test procedures.

[0132] Example 2, as Figure 3 As shown in the embodiments of this application, a control method for a transformer arc fault equivalent test device is also provided, including the following steps:

[0133] S1. Store the corresponding high-pressure gas based on the target pressure data calculated by the choke flow dynamic coupling model;

[0134] S2. Match the fault duration according to the test trigger command to release the high-pressure gas stored in the high-pressure gas storage unit;

[0135] S3. High-pressure gas is injected into the test tank to form a shock wave, and the interlock protection mechanism is activated based on the test data;

[0136] S4. Monitor the operation process of each unit in real time and identify the validity of the test data to optimize the initial parameters of the choke flow dynamic coupling model, thereby optimizing the test control process of the test device.

[0137] The above-described embodiments are preferred embodiments of this application and are not intended to limit the specific scope of this application. The scope of this application includes but is not limited to the specific embodiments described above. All equivalent changes made in accordance with the shape, structure, and method of this application are within the protection scope of this application.

Claims

1. A transformer arc fault equivalent test device, characterized in that: include: The high-pressure gas storage unit stores high-pressure gas based on the target pressure data calculated by the choke flow dynamic coupling model. The rapid release unit releases the high-pressure gas stored in the high-pressure gas storage unit by matching the fault duration according to the test trigger command; The energy injection unit injects high-pressure gas into the test tank to create a shock wave; The safety protection unit activates the interlocking protection mechanism based on test data; The monitoring and control unit controls the actions of each unit and monitors the operation of each unit in real time, acquiring and identifying the validity of test data to optimize the test process. Specifically, this includes: The system collects pressure and temperature data from the test tank in real time and calculates waveform consistency to identify the validity of the test data and establish a waveform mapping relationship. Specifically: pressure characteristics are obtained based on historical fault data, and a target waveform curve is established based on these characteristics; the optimal path distance between the test pressure curve in the test tank and the target waveform curve is calculated using a dynamic time warping algorithm; the optimal path distance is normalized to obtain the waveform consistency, and the waveform consistency is compared with a target threshold. If the waveform consistency is greater than or equal to the target threshold, the test is deemed valid, and the test data is marked as valid test data; if the waveform consistency is less than the target threshold, the test is deemed invalid, and the test data is marked as invalid test data; a waveform mapping relationship is obtained based on the marked test data and the corresponding test pressure curve. Based on the identified experimental data and waveform mapping relationships, parameters of the choke flow dynamic coupling model are corrected to optimize the experimental process. Specifically: Valid and invalid experimental data are preprocessed based on the waveform mapping relationships to determine baseline and supplementary samples for parameter correction; weights are assigned to the baseline and supplementary samples respectively; the weighted samples are iteratively calculated using the recursive least squares method according to the choke flow dynamic coupling model until the deviation between the waveform fit and the target threshold is minimized, thus obtaining the optimal parameters of the choke flow dynamic coupling model; and optimized target pressure data is obtained based on the optimal parameters to achieve adjustment and optimization of the experimental process.

2. The transformer arc fault equivalent test device according to claim 1, characterized in that: The high-pressure gas storage unit includes: The pressure calculation subunit calculates the mechanical energy required for the test based on the characteristics of the arc fault, according to the dynamic coupling model of the congested flow. Based on the mechanical energy, the fault time parameters, and the structural information of the gas transmission pipeline in the test device, the target pressure data is calculated. The inflation component inflates the air tank using the target pressure data as the inflation reference, and collects the pressure data inside the air tank in real time. The pressure monitoring component determines the inflation status based on the pressure data inside the gas tank and dynamically adjusts the two-stage pressure reducing valve to control the pressure balance of the gas tank.

3. The transformer arc fault equivalent test device according to claim 1, characterized in that: The rapid release unit includes: The status of the valve control mechanism and the status of the parallel-configured pipeline are verified according to the first self-test command sent by the monitoring and control unit. Based on the test trigger command and the duration of the fault, the valve control mechanism is controlled to open and close, thereby releasing the high-pressure gas.

4. The transformer arc fault equivalent test device according to claim 3, characterized in that: The energy injection unit includes: Determine the target interface of the test tank based on the target fault location information; Based on the opening control of the valve control mechanism by the rapid release unit, the released high-pressure gas is directed to the test oil tank through the target interface to form a shock wave that matches a real electric arc fault.

5. The transformer arc fault equivalent test device according to claim 4, characterized in that: The test tank verifies the safety status of the tank based on the second self-test command sent by the monitoring and control unit. Based on the safety verification result, the test tank generates mechanical energy of a real electric arc fault according to the high-pressure gas injected by the energy injection unit, and records the tank vibration data during the mechanical energy impact process.

6. The transformer arc fault equivalent test device according to claim 5, characterized in that: The safety protection unit triggers interlocking protection actions of each unit based on abnormal test conditions.

7. The transformer arc fault equivalent test device according to claim 1, characterized in that: The monitoring and control unit includes: The monitoring subunit generates corresponding control commands based on the test process to control the actions of each unit and monitor the operation process of each unit in real time.

8. A control method for a transformer arc fault equivalent test device, characterized in that: An equivalent test apparatus for transformer arc faults as described in any one of claims 1-7 includes the following steps: High-pressure gas storage is performed based on the target pressure data calculated using the choke flow dynamic coupling model. The high-pressure gas stored in the high-pressure gas storage unit is released according to the fault duration matched by the test trigger command. High-pressure gas is injected into the test tank to form a shock wave, and the interlock protection mechanism is activated based on the test data; The operation process of each unit is monitored in real time, and the validity of the test data is identified to optimize the initial parameters of the choke flow dynamic coupling model, thereby optimizing the test control process of the test device.

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