A method and system for calibrating an oscillating high voltage generator

Abstract

This application provides a calibration method and system for an oscillating high-voltage generator. The method includes: determining the product parameter between the total inductance and total capacitance of the oscillating circuit based on the interval between adjacent peaks, and determining the total damping parameter of the oscillating circuit based on the attenuation characteristics; performing thermal correction on preset generator reference parameters based on the generator thermal characterization parameters to obtain the generator thermal parameters; separating the oscillating circuit parameters into cable equivalent capacitance, cable equivalent loss parameters, and generator parameters; performing energy storage safety verification on the cable equivalent capacitance; generating a pre-charge voltage setting value for the next excitation based on the cable equivalent capacitance when the energy storage is within limits; correcting the generator control parameters for the next excitation based on the generator parameters; generating a correction amount based on the current first peak voltage deviation; and combining the pre-charge voltage setting value, generator control parameters, and correction amount according to the amplitude limiting conditions to form a control calibration parameter group for the next pre-examination excitation. This application achieves real-time compensation for generator thermal drift and identification of cable parameters, avoiding calibration deviation problems caused by generator thermal losses.

Description

Technical Field

[0001] This application relates to the field of oscillating high voltage generator calibration technology, specifically an oscillating high voltage generator calibration method and system. Background Technology

[0002] Oscillating wave partial discharge detection, high voltage pre-inspection excitation, and insulation condition analysis are gradually being applied to the operation and maintenance of high voltage cables. Typically, an oscillating high voltage generator is used to apply an oscillating high voltage signal or pulse excitation to the cable under test, and the insulation condition of the cable is analyzed based on the circuit oscillation.

[0003] However, after continuous discharge, the temperature rise of the conductive components, inductors, copper busbars, and switching devices in the oscillating high-voltage generator is inconsistent, causing drift in the circuit resistance, damping, and output waveform attenuation characteristics. If calibration is still performed according to the room temperature reference parameters, the generator's thermal losses will be mistaken for changes in the damping of the external load or the calibrated object, resulting in deviations in the calibration results.

[0004] Therefore, how to accurately identify cable parameters and generator parameters under dynamic thermal conditions, and realize adaptive calibration control based on real-time oscillation characteristics, has become a technical problem that urgently needs to be solved in the field of high-voltage oscillation testing. Summary of the Invention

[0005] To overcome the aforementioned problems in the prior art, this application provides a calibration method and system for an oscillating high-voltage generator, employing the following technical solution:

[0006] Firstly, this application provides a calibration method for an oscillating high-voltage generator, comprising:

[0007] The thermal characterization parameters, pre-charge voltage, high-voltage waveform, and loop current waveform of the excited cable are obtained. Based on the high-voltage waveform and loop current waveform, the first peak voltage, the interval between adjacent peaks, and the attenuation characteristics are obtained.

[0008] The product parameter between the total inductance and total capacitance of the oscillation circuit is determined based on the interval between adjacent peaks, and the total damping parameter of the oscillation circuit is determined based on the attenuation characteristics. The preset generator reference parameters are then thermally corrected based on the generator thermal characterization parameters to obtain the generator thermal parameters.

[0009] Based on the product parameter, total damping parameter, and generator thermal parameters, the oscillation circuit parameters are separated into cable parameters and generator parameters. The cable parameters include the cable equivalent capacitance and cable equivalent loss parameters.

[0010] The equivalent capacitance of the cable is checked for energy storage safety. If the energy storage does not exceed the limit, the pre-charge voltage setting value for the next excitation is generated based on the equivalent capacitance of the cable. The generator control parameters for the next excitation are corrected based on the generator parameters.

[0011] Based on the current first peak voltage deviation, a correction value is generated. The pre-charge voltage setpoint, generator control parameters, and correction value are then combined according to the limiting conditions to form the control calibration parameter group for the next pre-detection excitation.

[0012] Secondly, this application also provides a calibration system for an oscillating high-voltage generator, comprising:

[0013] The cable data acquisition module is used to acquire the thermal characteristics, pre-charge voltage, high-voltage waveform, and loop current waveform of the excited cable, and to acquire the first peak voltage, adjacent peak interval, and attenuation characteristics based on the high-voltage waveform and loop current waveform.

[0014] The generator hot-state parameter acquisition module is used to determine the product parameter between the total inductance and total capacitance of the oscillation circuit based on the interval between adjacent peaks, and to determine the total damping parameter of the oscillation circuit based on the attenuation characteristics; and to perform hot-state correction on the preset generator reference parameters based on the generator hot-state characterization parameters to obtain the generator hot-state parameters.

[0015] The oscillation circuit parameter separation module is used to separate the oscillation circuit parameters into cable parameters and generator parameters based on the product parameters, total damping parameters, and generator thermal parameters. The cable parameters include the cable equivalent capacitance and cable equivalent loss parameters.

[0016] The cable equivalent capacitance safety verification module is used to verify the energy storage safety of the cable equivalent capacitance. When the energy storage is within the limit, it generates the pre-charge voltage setting value for the next excitation based on the cable equivalent capacitance; and corrects the generator control parameters for the next excitation based on the generator parameters.

[0017] The calibration parameter determination module is used to generate a correction amount based on the current first peak voltage deviation, and to combine the pre-charge voltage set value, generator control parameters and correction amount into a control calibration parameter group for the next pre-detection excitation according to the limiting conditions.

[0018] Thirdly, this application provides an electronic device, comprising:

[0019] One or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the device, cause the device to perform the method as described in the first aspect.

[0020] Fourthly, this application provides a computer-readable storage medium storing a computer program that, when run on a computer, causes the computer to perform the method described in the first aspect.

[0021] Fifthly, this application provides a computer program that, when executed by a computer, performs the method described in the first aspect.

[0022] In one possible design, the program in the fifth aspect can be stored wholly or partially on a storage medium packaged with the processor, or it can be stored wholly or partially on a memory not packaged with the processor.

[0023] This application has the following beneficial effects:

[0024] 1. This application establishes a mapping relationship between the dynamic characteristics of the oscillating circuit and the circuit parameters by acquiring the first peak voltage, the interval between adjacent peaks, and the attenuation characteristics in the high voltage waveform and the circuit current waveform of the cable. It can obtain the total parameter information of the oscillating circuit in real time without additional offline measurement, thereby improving the parameter identification capability in the field testing process.

[0025] 2. This application determines the product parameter between the inductance and total capacitance of the oscillation circuit by the interval between adjacent peaks, and determines the total damping parameter by combining the attenuation characteristics. This realizes the conversion of the time-domain characteristic parameters of the oscillation circuit to the frequency-domain characteristics. Combined with the thermal characterization of the generator, the reference parameters of the generator are thermally corrected to generate thermal parameters, thus avoiding misjudging the damping change of the generator itself due to temperature rise as a change in cable or external load parameters.

[0026] 3. Based on the product parameter, total damping parameter and generator hot-state parameter, this application decouples and separates the oscillation circuit parameters, realizes the independent identification of cable parameters and generator parameters, and effectively avoids the interference of internal loss of hot-state generator on cable parameter determination by obtaining the equivalent capacitance and equivalent loss parameters of cable, thus solving the calibration deviation problem caused by thermal drift in traditional solutions.

[0027] 4. This application verifies the energy storage safety of the cable's equivalent capacitance and dynamically generates the pre-charge voltage setting value for the next excitation under the condition that the energy storage does not exceed the limit. This allows the excitation energy to be automatically adjusted according to the cable capacity, avoiding the risk of energy storage overload caused by large-capacity cables and avoiding the reduction of detection effectiveness due to insufficient energy in small-capacity cables, thus ensuring operational safety and measurement reliability during continuous excitation.

[0028] 5. This application corrects the generator control parameters for the next excitation based on the generator parameters, generates a correction amount by combining the current first peak voltage deviation, and integrates the pre-charge voltage setting, generator control parameters and correction amount through limiting conditions. In continuous excitation, the influence of thermal drift is gradually eliminated, the first peak voltage and oscillation waveform are stabilized, and the repeatability and consistency of calibration results are improved. Attached Figure Description

[0029] Figure 1This is a flowchart of a calibration method for an oscillating high-voltage generator according to an embodiment of this application;

[0030] Figure 2 This is a flowchart of step 110, data acquisition, in an embodiment of this application.

[0031] Figure 3 This is a flowchart of step 120, obtaining the product parameter, in an embodiment of this application.

[0032] Figure 4 This is a schematic diagram of the process for obtaining the thermal parameters of the generator according to an embodiment of this application;

[0033] Figure 5 This is a system flowchart of an embodiment of this application. Detailed Implementation

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0035] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0037] For on-site testing, partial discharge diagnosis, and withstand voltage testing of power cables, the oscillating wave high voltage generator needs to output a stable first peak voltage, oscillation frequency, and attenuation waveform that meet the test requirements when the cable under test is connected.

[0038] Currently, the control method of oscillating wave high-voltage generators is based on fixed parameters, and the excitation control is completed according to preset energy storage values ​​or empirical parameters. There is a lack of research on separating the changes in the generator from the changes in the load of the cable under test. During continuous testing, the main discharge switch and energy storage circuit devices generate significant heat accumulation due to repeated charging and discharging, leading to changes in conduction voltage drop, trigger delay, and equivalent impedance. Existing solutions provide uniform compensation for the overall waveform, failing to distinguish between the generator's own drift and the differences between cable load changes. This easily leads to misidentification of normal damping at the cable end as generator output error, resulting in incorrect compensation by increasing charging or adjusting control parameters, causing waveform distortion, energy overcompensation, and abnormal damping. For example, when the device temperature rises significantly, the main discharge switch's conduction capability decreases, leading to a reduction in the initial peak voltage; when the cable under test grows longer, the equivalent capacitance increases, also causing a reduction in the initial peak voltage. Because the waveforms of these two factors are similar, traditional methods struggle to determine whether the voltage deviation originates from generator thermal drift or cable load changes, thus failing to establish a stable and effective calibration method.

[0039] Based on this, to improve the output consistency of the oscillating wave generator under different load conditions and different thermal operating states, and to avoid parameter misjudgment caused by device thermal drift, power supply fluctuations, and cable damping, this application utilizes the loop parameter information contained in the oscillation period, first peak voltage, and attenuation characteristics, combined with the generator's thermal characterization parameters, to separate the generator parameters from the parameters of the cable under test. Based on the equivalent capacitance and equivalent loss parameters of the cable under test, the pre-charge voltage and generator control parameters are corrected. The cable damping attenuation is retained as an inherent attribute of the load without compensation, thus avoiding overcompensation and waveform distortion caused by the traditional uniform compensation threshold, and improving the waveform stability and test result reliability during the oscillating wave high voltage test.

[0040] Please refer to Figure 1 The following is a specific implementation process of a calibration method for an oscillating high-voltage generator provided in this application embodiment:

[0041] Step 110: Obtain the thermal characterization parameters, pre-charge voltage, high-voltage waveform, and loop current waveform of the excited cable. Based on the high-voltage waveform and loop current waveform, obtain the first peak voltage, adjacent peak interval, and attenuation characteristics.

[0042] The thermal characterization parameters represent at least one of the following: junction temperature, case temperature, on-state voltage drop, drive delay, or heatsink temperature of the power device. The pre-charge voltage represents the capacity build-up state of the energy storage unit before excitation. The cable high-voltage waveform represents the voltage response characteristics of the cable port during excitation. The loop current waveform represents the current change characteristics during the energy release process in the loop.

[0043] In one possible implementation, the thermal characteristics of the excited cable, pre-charge voltage, high-voltage waveform, and loop current waveform are acquired. Based on the high-voltage waveform and loop current waveform, the first peak voltage, the interval between adjacent peaks, and attenuation characteristics are obtained. Please refer to [reference needed]. Figure 2 The specific implementation process includes:

[0044] Step 21: A high-voltage pulse generator injects pulse excitation into the cable under test. A multi-channel acquisition device then acquires the thermal characteristics, pre-charge voltage, high-voltage waveform, and loop current waveform of the excited cable. The thermal characteristics are obtained in real-time through an array of infrared temperature sensors deployed on the surface of the cable joint or terminal. These thermal characteristics are a temperature vector composed of sampled values ​​from multiple key monitoring points. Specifically, the infrared temperature sensors convert the received radiation intensity into an electrical signal, which, after analog-to-digital conversion, generates a temperature value representing the cable's operating environment. This temperature value corrects for subsequent losses and eliminates calculation errors caused by ambient temperature fluctuations.

[0045] Step 22: The pre-charge voltage is the DC potential across the energy storage capacitor in the high-voltage pulse generator. This voltage is fed back to the control unit via a high-voltage divider. At the instant of the discharge switch, the transient voltage response of the cable's first segment is acquired at a sampling frequency of no less than 100MHz, forming the cable's high-voltage waveform. The charging and discharging current in the circuit is obtained based on the high-frequency current transformer installed on the return grounding wire, generating the circuit current waveform. For local cable detection, an LC oscillating wave pulse generator can be used; for lightning or impulse withstand voltage testing of cables, a Marx generator or a double-exponential impulse generator can be used; for conventional portable pulse detection, a solid-state switch pulse source or a single-stage capacitor discharge generator can be used. When subsequent steps require extracting the interval between adjacent peaks and attenuation characteristics, the high-voltage pulse generator should ensure that the tested cable, energy storage unit, circuit inductance, and circuit loss path form an observable attenuated oscillating circuit. For single-impact excitations that do not form an oscillating waveform, only the first peak voltage and peak attenuation trend are extracted, and they are not used for calculating the product parameters corresponding to the oscillation period.

[0046] Step 23, obtaining the first peak voltage, includes: identifying the initial jump point by performing zero-drift compensation processing on the high-voltage waveform of the cable; the first local extreme point after the initial jump point is determined as the first peak voltage. The first peak voltage represents the maximum electric field strength instantaneously injected into the cable, and serves as the data basis for evaluating the nonlinear response of the insulating medium under high electric field strength. The zero-drift compensation processing includes calculating the voltage baseline using the static sampling segment before the discharge switch is closed, and subtracting this voltage baseline from the high-voltage waveform of the cable; the initial jump point is the sampling point where the voltage change rate first exceeds a preset change rate threshold. The first peak voltage is expressed as voltage amplitude; if it is necessary to represent the electric field strength in the cable insulation, the first peak voltage is converted into an equivalent electric field strength based on the cable insulation thickness or equivalent electric field distance.

[0047] Step 24, obtaining the adjacent peak interval, includes: based on the loop current waveform, identifying continuous oscillation periods through autocorrelation analysis. The adjacent peak interval is the time difference between two adjacent positive current peaks; changes in the time difference indicate discontinuities in the cable's internal impedance. Specifically, the loop current waveform is bandpass filtered to retain the main oscillation frequency band; the main period position is determined through the autocorrelation function, and continuous positive current peaks are searched near the main period position. The adjacent peak interval represents the oscillation period of this damped oscillation loop, and the product parameter between the total inductance and total capacitance is determined based on this oscillation period. For peak distortion caused by local impedance discontinuities, abnormal peak intervals deviating from the main period by more than a preset proportion are removed, and the average or median value of the remaining peak intervals is used as the adjacent peak interval.

[0048] Step 25 involves obtaining attenuation characteristics, including: performing a Hilbert transform on the oscillation sequence of the loop current waveform to generate an analytic signal and extract the instantaneous envelope; calculating the attenuation coefficient based on exponential fitting according to the peak evolution trend of the instantaneous envelope; and using the attenuation coefficient as the attenuation characteristic, which is a core indicator for assessing the degree of cable aging. To ensure the attenuation characteristic corresponds to the total damping parameter, the envelope peaks in the instantaneous envelope are arranged in chronological order to form an envelope peak sequence. An exponential attenuation fitting is then performed on the envelope peak sequence to obtain the attenuation coefficient representing the rate of amplitude decrease per unit time. This attenuation coefficient serves as the input for calculating the total damping parameter, rather than being directly equivalent to the cable loss; subsequently, it needs to be combined with the generator loss subtraction process to obtain the cable's equivalent loss parameter.

[0049] In this step, the acquisition time of the first peak voltage is used as the reference time. The start time of the loop current waveform needs to be aligned with the reference time. If the phase offset between the reference time and the start time exceeds a preset threshold, the data acquisition is considered a failure and needs to be re-acquired. The phase offset can be determined by the time difference between the start transition point of the cable high-voltage waveform and the start transition point of the loop current waveform, and converted into a ratio relative to the interval between adjacent peaks. When this ratio exceeds the preset threshold, it indicates that the voltage channel and the current channel do not correspond to the same effective excitation, and the waveform data for that instance is discarded.

[0050] In this step, during the extraction of attenuation features, a pre-charge voltage is introduced for normalization to eliminate waveform amplitude differences caused by varying excitation energies, ensuring the comparability of attenuation features at different levels. Specifically: when extracting attenuation features, the pre-charge voltage and the cable high-voltage waveform corresponding to the current excitation are obtained; multiple peaks are extracted from the cable high-voltage waveform to form a peak sequence; the pre-charge voltage is used as a normalization factor to normalize each peak in the peak sequence, resulting in a normalized peak sequence; based on the attenuation relationship between adjacent peaks in the normalized peak sequence, attenuation features are generated. When attenuation features are extracted from the loop current waveform, the current envelope peak is normalized using the initial energy storage state corresponding to the pre-charge voltage; when attenuation features are extracted from the cable high-voltage waveform, the voltage peak sequence is normalized using the pre-charge voltage.

[0051] Specifically, the pre-charge voltage and cable high-voltage waveform corresponding to this excitation are read. The pre-charge voltage represents the initial voltage level applied to the cable side before excitation, and the cable high-voltage waveform represents the decaying oscillation process of the cable terminal voltage over time after excitation. Since different pre-charge voltages will cause the overall amplitude of the first peak voltage and subsequent peak values ​​to increase or decrease, if the original peak values ​​are directly used to extract attenuation features, the attenuation result will simultaneously include differences in excitation energy and cable loss. To eliminate this effect, multiple peak values ​​of the same polarity or absolute values ​​of peak values ​​are extracted from the cable high-voltage waveform to form a peak sequence. Using the pre-charge voltage corresponding to this excitation as the normalization benchmark, each peak in the peak sequence is divided by the pre-charge voltage to obtain the normalized peak sequence. The values ​​in the normalized peak sequence represent the relative amplitude of each peak value with respect to the current pre-charge voltage, thus eliminating the overall amplitude difference caused by different pre-charge voltage levels. Before performing normalization, it is determined whether the pre-charge voltage is greater than a preset effective voltage threshold; if the pre-charge voltage is lower than this threshold, attenuation feature extraction is not performed to avoid calculation distortion caused by an excessively small normalization denominator.

[0052] After obtaining the normalized peak sequence, attenuation features are extracted based on the attenuation relationship between adjacent normalized peaks. For example, the ratio, difference, or logarithmic attenuation between the i-th and (i+1)-th normalized peaks is calculated, and the attenuation features are obtained based on the logarithmic attenuation of multiple adjacent peaks. These calculations are performed on the normalized peak sequence, and the resulting attenuation features mainly reflect the rate at which the waveform amplitude decreases with the number of oscillations or time, rather than the initial amplitude difference caused by the pre-charge voltage. The logarithmic ratio of adjacent normalized peaks is calculated, and the attenuation per unit time is obtained by combining the interval between adjacent peaks; multiple attenuation per unit time are averaged or fitted to form the attenuation features.

[0053] For example, in the initial detection stage, the operating parameters of the sensor array deployed on the main discharge circuit, energy storage unit, and charging branch are continuously collected. The sensor array feeds back the thermal characterization of the cable surface and the internal pre-charging progress to the processing unit. When the monitored pre-charging voltage reaches the preset excitation threshold, the discharge circuit is closed, generating a transient pulse and activating the high-speed analog-to-digital converter to sample the voltage and current waveforms at the moment of discharge at high speed. The sampling window is set between 10 microseconds and 1 millisecond to ensure complete coverage of the entire process of oscillation establishment, peak appearance, and attenuation changes. By acquiring the transient waveform, the dynamic response characteristics of the cable circuit under high-voltage excitation are obtained. The specific length of the sampling window is determined based on the estimated range of the interval between adjacent peaks, covering at least the first peak voltage and two subsequent peaks of the same polarity. If a sufficient number of effective peaks appear within the sampling window, it is determined that the waveform is insufficient to extract the interval between adjacent peaks and attenuation characteristics.

[0054] In the feature extraction stage, a sliding window maximum search algorithm is used to scan the acquired transient voltage waveform segment by segment, identifying the heuristic peak that dictates the voltage as the first peak voltage. This method quickly locates the maximum amplitude point within complex oscillating waves, avoiding interference from local noise in traditional single-point comparison methods, and determining the initial intensity of the excitation energy. The length of the sliding window is determined based on the sampling frequency and the estimated oscillation period. Candidate extreme points within the window must simultaneously satisfy the following conditions: amplitude greater than the noise threshold, a change in the sign of the slope before and after the transition, and a time interval between the extreme point and the initial jump point within the preset first peak search range. The first valid local extreme point that meets these conditions is identified as the first peak voltage.

[0055] It should be noted that the generator and the cable under test are connected in a pulse-damping oscillation circuit when pulse excitation is applied. The energy storage unit of the generator, the discharge switch, the circuit inductance, the equivalent capacitance of the cable under test, the return path, and the circuit loss together form the damped oscillation circuit; the high voltage waveform of the cable reflects the voltage response of this circuit at the cable port, and the circuit current waveform reflects the energy release current in this circuit.

[0056] Step 120: Determine the product parameter between the total inductance and total capacitance of the oscillation circuit based on the adjacent peak interval, and determine the total damping parameter of the oscillation circuit based on the attenuation characteristics; perform hot-state correction on the preset generator reference parameters based on the generator hot-state characterization, and obtain the generator hot-state parameters. The adjacent peak interval, attenuation characteristics, and generator hot-state characterization are all processing results obtained in step 110 within the same calibration triggering process or the same hot-state sampling window.

[0057] In this embodiment, the product parameter between the total inductance and total capacitance of the oscillation circuit is determined based on the interval between adjacent peak values. Please refer to [reference needed]. Figure 3 The specific implementation includes:

[0058] Step 31, interval between adjacent peaks Substitute into the preset oscillation frequency calculation model Obtain the equivalent oscillation frequency of the oscillation circuit. The interval between adjacent peaks is the time difference between adjacent peaks of the same polarity. When the interval between positive and negative peaks is collected, the sum of the intervals between two consecutive peaks of opposite polarity is taken as an oscillation period, or the interval between peaks of opposite polarity is multiplied by 2 and taken as the interval between adjacent peaks, so as to ensure that the interval between adjacent peaks corresponds to a complete oscillation period.

[0059] Step 32, based on the equivalent oscillation frequency and the total inductance of the loop. and total capacitance Frequency constraint relationship between Establish the relationship between adjacent peak intervals, the product of total inductance and total capacitance. The mapping relationship is based on a preset formula. Calculate the product parameter of the total capacitance and total inductance of the circuit.

[0060] In one possible implementation, determining the total damping parameter of the oscillating circuit based on attenuation characteristics includes: determining an estimated value of the total inductance of the circuit based on a preset empirical value of the distributed inductance per unit length of the cable and a product parameter. ;according to Determine the total damping parameters of the oscillating circuit The total damping parameter represents the equivalent damping formed by the generator's internal resistance, the cable conductor resistance, and the insulation dielectric loss. Applicable to the series equivalent RLC damped oscillation model. This is the attenuation coefficient in the voltage envelope exponential attenuation term.

[0061] The process of obtaining the total inductance estimate includes: based on the preset empirical value of the distributed inductance per unit length of the cable. The actual cable length input on site Obtain the total distributed inductance of the cable. The total distributed inductance of the cable With generator registered inductance The values ​​are superimposed to obtain an estimate of the total inductance of the loop. In obtaining Afterwards, and Dividing gives the estimated total capacitance of the loop. The estimated total capacitance of this circuit is used together with the generator's hot parasitic capacitance value to participate in the subsequent separation calculation of the equivalent capacitance of the cable insulation layer.

[0062] The preset empirical value of the distributed inductance per unit length of the cable is obtained from a preset parameter database based on the signal specifications of the cable under test, representing the energy storage characteristics of the cable per unit length under standard conditions. The generator's registered inductance is the inherent inductance value measured by a high-frequency impedance analyzer during the factory or calibration stage through a short-circuit test at the generator output terminal, representing the combined parasitic inductive reactance of the inductive elements, internal connecting buses, and switching devices in the discharge circuit. By distinguishing the increase in inductive reactance generated by a known length from the inherent inductive reactance of the equipment, a data basis is provided for the subsequent inversion of the equivalent capacitance of the cable insulation layer.

[0063] In this embodiment, the preset generator reference parameters are thermally corrected based on the generator's thermal characterization parameters to obtain the generator's thermal parameters. Please refer to [reference needed]. Figure 4 The specific content includes:

[0064] Step 41: Obtain the instantaneous temperature field distribution sequence, shell thermal strain displacement data, and pressure pulse frequency from the generator's thermal characterization parameters. The preset generator reference parameters include the nominal inductance value, basic DC resistance, winding geometric distribution parameters, and the initial dielectric constant of the insulating medium. The instantaneous temperature field distribution sequence represents the temperature rise at different locations along the generator's conductive path. Temperature rise changes conductor resistivity; therefore, the instantaneous temperature field distribution sequence is used to correct the basic DC resistance. The shell thermal strain displacement data represents the structural offset of the generator shell under hot conditions. This structural offset affects the conductive path geometry of the oscillating circuit inductor components through the support structure, assembly gaps, or fixed connections; therefore, it is used to correct the inductance parameters. The pressure pulse frequency represents the pressure disturbance of the insulating or cooling medium under hot conditions. Pressure disturbance changes the medium density or dielectric state; it is used to correct the generator's parasitic capacitance parameters.

[0065] Step 42: Determine the equivalent deformation of the winding structure based on the thermal strain displacement data of the shell, reconstruct the winding geometric distribution parameters based on the equivalent deformation, and generate the initial corrected inductance value; perform temperature drift compensation on the basic DC resistance based on the instantaneous temperature field distribution sequence to generate the real-time internal resistance; and correct the initial dielectric constant of the insulating medium based on the pressure pulse frequency to generate the parasitic capacitance correction amount.

[0066] In this step, the equivalent deformation of the winding structure is determined based on the shell thermal strain and displacement data. This includes: normalizing the coordinates of the shell thermal strain and displacement data; mapping the strain and displacement values ​​at different sampling locations to a preset generator structural coordinate system. The preset generator structural coordinate system uses the winding center axis as the axial reference, the winding radial expansion as the radial reference, and the winding circumferential direction as the circumferential reference, forming a three-dimensional thermal deformation data field of the winding.

[0067] The three-dimensional deformation data field of the winding under thermal conditions is input into the preset structural topology mapping model. The nodes of the winding structure are discretized. The preset structural topology mapping model includes at least the connection relationship of the winding nodes, the interlayer constraint relationship, the skeleton support relationship and the end compression constraint relationship. The local thermal elongation is calculated based on the strain value corresponding to each node. The node spatial offset vector is calculated based on the displacement data of each node, and the node deformation matrix of the winding structure under thermal conditions is generated.

[0068] For any structural node, the local thermal elongation is determined based on the corresponding thermal strain value and the initial structural length, and the local thermal elongation satisfies the following conditions: ,in Indicates local thermal elongation. This represents the thermal strain value at the corresponding node. This indicates the initial structural length of the corresponding structural unit.

[0069] Spatial topology reconstruction is performed based on the node deformation matrix; the equivalent radius expansion of the winding is determined based on the radial displacement component; the change in the inter-turn distance of the winding is determined based on the axial displacement component; the inter-layer deflection angle of the winding is determined based on the circumferential displacement component; and the overall eccentricity of the winding is determined based on the relative offset between adjacent nodes.

[0070] After completing the spatial topology reconstruction, the equivalent deformation of the winding structure is calculated based on the spatial positional changes of each winding node under the hot state. The equivalent deformation represents the degree of deviation of the overall geometric structure of the winding from the calibration state. The equivalent deformation includes at least the equivalent radius change, the equivalent shaft length elongation, the interlayer coupling offset, and the overall winding eccentricity.

[0071] The radial displacement component is based on a radial micro-displacement sensor installed on the winding shell or winding layer. After the winding is heated, the radial expansion displacement is collected, and the radial displacement component of each node is calculated according to the sensor calibration value and the initial radius. ,in Indicates the sensor calibration value. The initial radius is represented. The circumferential displacement components are mapped to the radius coordinate system in the direction of the center axis to obtain the radial thermal expansion of each node. The radial thermal expansion vectors of all nodes are spatially averaged and weighted to obtain the equivalent radius expansion of the winding, which represents the radial scale change trend of the winding as a whole under thermal conditions.

[0072] The axial displacement component is defined with the winding center axis as the Z-axis reference, a fixed reference surface as the zero point, and the cold-state axial coordinates are defined. The spatial displacement signal of the nodes is acquired in real time by displacement sensors installed at the ends of the windings or the support points of the frame. The spatial displacement signal is projected onto the axial direction of the winding to obtain the axial displacement component. ,in The angle between the displacement direction and the axis is given. The axial displacement components of adjacent nodes are accumulated to obtain the change in winding turn distance. For the axial displacement of different nodes within the same turn, a differential calculation is performed, retaining only the effective turn distance change caused by thermal expansion.

[0073] The circumferential displacement component is the spatial displacement signal. Projecting onto the tangential direction of the circle, obtain the circumferential displacement components. ,in This indicates the angle between the displacement direction and the radial direction. The interlayer deflection angle of the winding is... This represents the sequence of circumferential displacement distribution between node layers. Statistical analysis of the deflection angles of nodes at different levels forms the overall deflection characteristics between components, representing the torsional trend of the winding structure under thermo-mechanical coupling.

[0074] The relative offset between adjacent nodes includes radial, axial, and circumferential displacement components. Based on these offsets, a node spatial difference vector matrix is ​​constructed. By calculating the combined displacement difference between node pairs in the radial, axial, and circumferential directions, structural asymmetry features are extracted. Weighted integration and center offset correction are applied to the relative offsets of all node pairs to obtain the overall winding eccentricity, representing the degree of overall offset of the winding relative to the geometric center axis during hot operation.

[0075] The thermal strain displacement data of the shell includes at least radial thermal expansion displacement, axial thermal elongation displacement, and winding interlayer offset displacement.

[0076] In this step, the winding geometric distribution parameters are reconstructed based on equivalent deformation to generate an initial corrected inductance value. This includes: calculating the equivalent radius expansion of the winding based on radial thermal expansion displacement; calculating the change in axial spacing between winding turns based on axial thermal elongation displacement; and determining the relative deflection vector between adjacent winding layers based on inter-layer offset displacement. Based on the equivalent radius expansion, the change in axial spacing between turns, and the relative deflection vector, the winding geometric distribution parameters are dynamically reconstructed. These parameters include at least the average winding radius, effective flux coupling distance, turn density per unit length, and inter-layer coupling coefficient. Because the relative spatial position between conductors changes after the winding expands due to thermal expansion, the magnetic field coupling path and leakage flux distribution change. Therefore, the winding flux path length and magnetic field coupling area are simultaneously corrected. The reconstructed winding geometric distribution parameters are input into a preset inductance calculation model. The equivalent inductive reactance parameters under hot conditions are recalculated using the magnetic field integral relationship. The preset inductance calculation model is established based on the correlation between winding spatial distribution, current path length, and magnetic field coupling strength, representing the impact of thermal deformation on energy storage capacity. The output is the initial corrected inductance value corresponding to the current hot state structure. The initial corrected inductance value is used to perform residual verification with the measured oscillation waveform and is used as the inductive reactance parameter of the generator hot state parameter to perform decoupling calculation with the oscillation circuit.

[0077] In this step, temperature drift compensation is performed on the basic DC resistance based on the instantaneous temperature field distribution sequence to generate real-time internal resistance. This includes: dividing the basic DC resistance into multiple resistance calculation segments according to the spatial distribution of the conductive path, and mapping temperature points in the instantaneous temperature field distribution sequence to the corresponding resistance calculation segments. When a resistance calculation segment corresponds to multiple temperature points, the equivalent temperature of the segment is determined based on the temperature point coverage length or the spatial distance of the resistance calculation segment. Based on the temperature difference between the equivalent temperature and the reference temperature, temperature drift compensation is performed on the reference resistance of the resistance calculation segment. After each resistance calculation segment is compensated, the thermal internal resistance of each segment is summarized based on the electrical connection relationship of the conductive path to generate real-time internal resistance. The real-time internal resistance, as the loss parameter of the generator's own conductive path under the current thermal state, is written into the resistance loss parameter item of the preset oscillation circuit model.

[0078] In this step, the initial dielectric constant of the insulating medium is corrected according to the pressure pulse frequency to generate a parasitic capacitance correction amount. This includes: extracting the dominant pulsation frequency from the pressure pulsation signal; correcting the initial dielectric constant of the insulating medium according to the preset pressure pulse frequency and dielectric constant correction relationship to obtain the hot dielectric constant; where the hot dielectric constant represents the dielectric state under the current medium pressure disturbance; and calculating the parasitic capacitance correction amount between the high-voltage end of the generator, the shell, and adjacent conductive structures by combining the hot geometric distribution parameters; when the hot geometric distribution parameters have been obtained in the inductance correction process, the parasitic capacitance correction amount is calculated using the same hot geometric distribution parameters to ensure that the inductance correction and parasitic capacitance correction use the same structural state.

[0079] Step 43: Input the initial corrected inductance value, real-time internal resistance and parasitic capacitance correction amount into the preset oscillation circuit model to generate a theoretical oscillation waveform. Compare the theoretical oscillation waveform with the measured decaying oscillation waveform to obtain the residual result.

[0080] The preset oscillation circuit model is established based on the equivalent RLC decay oscillation circuit during the calibration discharge of the oscillating high-voltage generator. It includes inductance parameters, resistance loss parameters, capacitance parameters, and initial excitation parameters. The inductance parameter is used to receive the initial correction inductance value; the resistance loss parameter is used to receive the real-time internal resistance; the capacitance parameter is used to receive the generator reference capacitance and parasitic capacitance correction; and the initial excitation parameter is used to represent the initial voltage or initial energy storage state at the calibration trigger moment.

[0081] When the preset oscillation circuit model is working, the initial corrected inductance value is written into the inductance parameter item, the real-time internal resistance is written into the resistance loss parameter item, the parasitic capacitance correction is written into the capacitance parameter item, the initial excitation parameter item is set according to the voltage state at the calibration trigger time, and the theoretical oscillation waveform is generated according to the RLC decay oscillation relationship. The oscillation period in the theoretical oscillation waveform is jointly determined by the inductance parameter item and the capacitance parameter item, the decay envelope is jointly determined by the resistance loss parameter item and the inductance parameter item, and the voltage amplitude sequence is jointly determined by the initial excitation parameter item, the capacitance parameter item, and the resistance loss parameter item.

[0082] The theoretical oscillation waveform is time-aligned with the measured decaying oscillation waveform acquired within the same hot-state sampling window, and the period residual, decay residual, and amplitude residual are extracted respectively. The period residual is used to check whether the inductance and capacitance parameters can explain the measured oscillation period; the decay residual is used to check whether the resistance loss parameter can explain the envelope descent rate of the measured waveform; and the amplitude residual is used to check whether the capacitance and initial excitation parameters can explain the measured amplitude distribution.

[0083] Step 44: Based on the residual results, iteratively correct the initial correction inductance value, real-time internal resistance, and parasitic capacitance correction amount to obtain the generator thermal parameters representing the current thermal operating characteristics of the oscillating high voltage generator.

[0084] When the residual does not meet the convergence condition, iterative correction is performed according to the correspondence between the residual and the parameters of the preset oscillation circuit model. When the period residual exceeds the preset range, the initial correction inductance value is corrected; when the attenuation residual exceeds the preset range, the real-time internal resistance is corrected; when the amplitude residual exceeds the preset range, the parasitic capacitance correction amount is corrected. After each correction, the updated parameters are rewritten into the preset oscillation circuit model, the theoretical oscillation waveform is regenerated, and the residual is compared.

[0085] To avoid obtaining values ​​that do not conform to the actual state of the equipment during the iteration process, physical boundaries are set for each parameter. The boundary of the initial correction inductance value is determined by the allowable geometric variation range of the conductive path of the inductor component; the boundary of the real-time internal resistance is determined by the temperature field range, the temperature coefficient of the conductor material, and the basic DC resistance; the boundary of the parasitic capacitance correction is determined by the allowable variation range of the dielectric constant of the insulating medium and the geometric constraints of the conductive structure. When the correction value of a parameter exceeds the corresponding boundary, the parameter is limited to the boundary range, and the calculation of the preset oscillation circuit model and residual verification continue.

[0086] Once the residual between the theoretical oscillation waveform and the measured damped oscillation waveform satisfies the convergence condition, the inductance parameters, internal resistance parameters, and parasitic capacitance parameters after iterative convergence are combined to form the generator's hot-state parameters. The inductance parameter uses the initial corrected inductance value as the initial value for iteration, and is corrected by the periodic residual constraint to form the hot-state inductance value. The internal resistance parameter uses the real-time internal resistance as the initial value for iteration, and is corrected by the damping residual constraint to form the hot-state internal resistance value. The parasitic capacitance parameter uses the parasitic capacitance correction amount as the initial value for iteration or the capacitance offset amount, and is corrected by the periodic residual and / or amplitude residual constraint to form the hot-state parasitic capacitance value. The generator's hot-state parameters include the hot-state inductance value obtained by convergence from the initial corrected inductance value, the hot-state internal resistance value obtained by convergence from the real-time internal resistance, and the hot-state parasitic capacitance value obtained by convergence from the parasitic capacitance correction amount.

[0087] The generator's hot-state parameters can be associated with the hot-state sampling window identifier, calibration trigger time, and residual convergence results. The hot-state sampling window identifier is used to limit the source of temperature, structural deformation, pressure pulsation, and measured waveform data corresponding to this set of hot-state parameters. The calibration trigger time is used to determine the excitation process applicable to this set of parameters. The residual convergence results are used to record the fitting state between the theoretical oscillation waveform and the measured decaying oscillation waveform. The generator's hot-state parameters not only represent the equivalent loop characteristics of the oscillating high-voltage generator under the current hot-state operating condition, but can also serve as inputs for cable parameter separation.

[0088] Step 130: Based on the product parameter, total damping parameter and generator hot-state parameter, the oscillation circuit parameter is separated into cable parameter and generator parameter. The cable parameter includes the cable equivalent capacitance and cable equivalent loss parameter. The cable equivalent loss parameter is only recorded for cable damping attenuation and is not used as a generator error to compensate for it.

[0089] Specifically, within the same hot-state sampling window, an inductor-capacitor coupling model is established based on the periodic constraint relationship of the oscillation circuit. The product parameter is correlated with the hot-state inductance value in the generator's hot-state parameters to determine the total equivalent capacitance of the oscillation circuit. Before performing the correlation calculation, the hot-state inductance value in the generator's hot-state parameters is used as the basis for the correlation calculation. Estimated value of cable distributed inductance Determine the total inductance of the hot loop. ,in When the hot-state inductance value in the generator's hot-state parameters has been defined as the total hot-state inductance of the loop, including the generator inductance and the cable's distributed inductance, this hot-state inductance value is directly used as... .based on Calculate the total equivalent capacitance .

[0090] Based on the geometric deformation vector and dynamic dielectric constant of the generator's thermal parameters, the equivalent capacitance distribution model inside the generator is reconstructed, the generator's capacitance contribution is calculated, and the equivalent capacitance of the cable is obtained by subtracting the capacitance contribution from the total equivalent capacitance. The total equivalent capacitance is composed of the generator's parallel capacitance and the equivalent capacitance of the external cable.

[0091] Based on the mapping relationship between the total damping parameter and the hot-state inductance value, the total damping parameter is converted into the total equivalent loss parameter. Based on the hot-state internal resistance value in the generator's hot-state parameters, the generator's equivalent loss contribution is calculated. The equivalent loss contribution is then subtracted from the total equivalent loss parameter to obtain the cable's equivalent loss parameter. The total equivalent loss parameter represents the equivalent dissipation capacity required to match the theoretical attenuation oscillation envelope with the measured attenuation envelope under the current oscillation circuit inductance conditions. The generator's equivalent loss contribution is expressed using the hot-state internal resistance value in the generator's hot-state parameters. The equivalent loss parameters of the cable meet the requirements. The equivalent loss parameter of the cable is used to record the attenuation contribution caused by the conductor resistance, insulation dielectric loss and connection end loss of the external cable, and is written into the cable parameter record item, but not into the generator error compensation item.

[0092] The same hot-state sampling window is set to the first 5 to 10 complete oscillation cycles after generator excitation, ensuring that the acquired product parameters and the generator's hot-state parameters are at a steady-state thermal equilibrium cross-section. The product parameters are extracted from the measured waveform. The correlation calculation is performed with the hot inductance value in the generator's hot parameters, through... The mapping relationship is used to calculate the total equivalent capacitance, including cable energy storage and generator parasitic energy storage. An initial charge distribution view is established based on the measured frequency and constrained by the hot inductance correction value. The inductor-capacitor coupling model describes the correspondence between the oscillation period and the total equivalent inductance and total equivalent capacitance of the circuit. The initial charge distribution view includes at least three types of charge-carrying objects: total equivalent capacitance, generator capacitance contribution, and cable equivalent capacitance, used to identify the distribution relationship of total energy storage between the generator and the cable.

[0093] Step 140: Perform energy storage safety verification on the cable equivalent capacitance. If the energy storage does not exceed the limit, generate the pre-charge voltage setting value for the next excitation based on the cable equivalent capacitance; correct the generator control parameters for the next excitation based on the generator parameters. The cable equivalent capacitance and generator parameters are derived from the parameter separation results obtained in step 130 within the current hot-state sampling window; the generator parameters include at least the generator's hot-state inductance, hot-state internal resistance, and hot-state parasitic capacitance values. The cable equivalent loss parameter is written into the current cable status record along with the cable equivalent capacitance as a cable-side attenuation record item, but it does not participate in generator error compensation.

[0094] Specifically, the cable energy storage value corresponding to the candidate pre-charge voltage for the next excitation is calculated based on the cable's equivalent capacitance. This value is then compared to a preset upper limit. If the cable energy storage value does not exceed the preset upper limit, the candidate pre-charge voltage is determined as the pre-charge voltage setting value for the next excitation. If the cable energy storage value exceeds the preset upper limit, an allowable upper limit for the pre-charge voltage is determined based on the cable's equivalent capacitance and the preset upper limit, and the pre-charge voltage setting value for the next excitation is limited accordingly. When the candidate pre-charge voltage exceeds the allowable upper limit, the pre-charge voltage setting value for the next excitation is updated to be no greater than a preset limit value, and an energy storage limit indicator is generated. When the cable's equivalent loss parameter exceeds a preset cable loss recording threshold, only a cable attenuation anomaly record or warning message is generated; the cable's equivalent loss parameter is not written into the error compensation item of the generator control parameters.

[0095] Once the pre-charge voltage setpoint is determined, generator control parameters are determined based on the offset relationship between the generator parameters and the preset generator reference parameters. The generator parameters at least represent the influence of the generator's hot-state inductance, hot-state internal resistance, hot-state parasitic capacitance, or equivalent loss on the next excitation waveform. The generator control parameters are used to control the charging cutoff, trigger timing, discharge switch action, compensation branch switching, or damping branch adjustment during the next excitation process. The offset relationship between the generator parameters and the preset generator reference parameters includes the hot-state inductance offset, hot-state internal resistance offset, and hot-state parasitic capacitance offset. Based on these offsets, a preset control correction table is consulted or a preset control parameter calculation model is input to obtain the charging cutoff correction, trigger delay correction, compensation branch switching status, and damping branch adjustment. The generator control parameters are generated only based on the generator parameter offsets; the cable equivalent loss parameters are not included in the above offset calculations. After generating the pre-charge voltage setpoint and generator control parameters for the next excitation, the pre-charge voltage setpoint, generator control parameters, corresponding cable equivalent capacitance, cable equivalent loss parameters, energy storage limit indicator, and hot sampling window indicator are associated and stored. During the next excitation, the controller performs charging control according to the pre-charge voltage setpoint and performs trigger timing, discharge switch, compensation branch or damping branch control according to the generator control parameters.

[0096] Step 150: Generate a correction value based on the current first peak voltage deviation. Combine the pre-charge voltage setpoint, generator control parameters, and correction value according to the limiting conditions to form the control calibration parameter set for the next pre-detection excitation. The pre-charge voltage setpoint and generator control parameters are the next excitation control results generated in step 140; the current first peak voltage deviation... Measured first peak voltage from the current pre-detection excitation or the current calibration excitation With the target first peak voltage The difference between them is determined to satisfy The target peak voltage is determined by the target waveform in the test procedure, the preset test voltage level, or the external test task instruction.

[0097] In this step, when synthesizing the control calibration parameter set, the pre-charge voltage setpoint, the correction amount corresponding to the first peak voltage deviation, and the generator control parameters are constrained according to the limiting conditions. The limiting conditions are used to limit the voltage amplitude, energy storage level, and generator operating range in the next pre-test excitation, so that the corrected control parameters do not exceed the equipment safety boundary and the allowable range of the test procedure. Among them, the limiting conditions include at least the upper limit of the pre-charge voltage, the lower limit of the pre-charge voltage, the upper limit of cable energy storage, the allowable range of trigger delay, the allowable state of compensation branch switching, and the allowable range of damping branch adjustment; the upper limit of the pre-charge voltage includes the allowable upper limit of the pre-charge voltage calculated in step 140 based on the cable equivalent capacitance and the preset upper limit of energy storage.

[0098] When the cable energy storage value corresponding to the candidate calibration pre-charge voltage exceeds the upper limit of cable energy storage, the candidate calibration pre-charge voltage is limited to a value no greater than the upper limit of the allowable pre-charge voltage. When the candidate generator control parameters exceed the corresponding operating range, they are limited to the preset generator operating boundary. After limiting, the limited pre-charge voltage, the limited generator control parameters, the first peak voltage deviation, the correction amount, the limiting status indicator, and the corresponding hot sampling window indicator are combined into the control calibration parameter group for the next pre-detection excitation.

[0099] Please refer to Figure 5 This application provides a calibration system for an oscillating high-voltage generator, which includes the following modules:

[0100] The cable data acquisition module 510 is used to acquire the thermal characterization parameters, pre-charge voltage, high-voltage waveform, and loop current waveform of the excited cable, and to acquire the first peak voltage, adjacent peak interval, and attenuation characteristics based on the high-voltage waveform and loop current waveform.

[0101] The generator hot-state parameter acquisition module 520 is used to determine the product parameter between the total inductance and total capacitance of the oscillation circuit based on the interval between adjacent peaks, and to determine the total damping parameter of the oscillation circuit based on the attenuation characteristics; and to perform hot-state correction on the preset generator reference parameters based on the generator hot-state characterization parameters to obtain the generator hot-state parameters.

[0102] The oscillation circuit parameter separation module 530 is used to separate the oscillation circuit parameters into cable parameters and generator parameters based on the product parameters, total damping parameters, and generator thermal parameters. The cable parameters include the cable equivalent capacitance and cable equivalent loss parameters.

[0103] The cable equivalent capacitance safety verification module 540 is used to perform energy storage safety verification on the cable equivalent capacitance. When the energy storage does not exceed the limit, it generates the pre-charge voltage setting value for the next excitation based on the cable equivalent capacitance; and corrects the generator control parameters for the next excitation based on the generator parameters.

[0104] The calibration parameter determination module 550 is used to generate a correction amount based on the current first peak voltage deviation, and to combine the pre-charge voltage set value, generator control parameters and correction amount into a control calibration parameter group for the next pre-detection excitation according to the limiting conditions.

[0105] This application determines the product parameter between the total inductance and total capacitance of the oscillation circuit based on the interval between adjacent peaks, and determines the total damping parameter of the oscillation circuit based on the attenuation characteristics; it obtains the generator's thermal parameters by performing thermal correction on the preset generator reference parameters based on the generator's thermal characterization parameters; it separates the oscillation circuit parameters into the cable's equivalent capacitance, cable's equivalent loss parameters, and generator parameters, performs energy storage safety verification on the cable's equivalent capacitance, and generates the pre-charge voltage setting value for the next excitation based on the cable's equivalent capacitance when the energy storage is within the limit; it corrects the generator control parameters for the next excitation based on the generator parameters; it generates a correction amount based on the current first peak voltage deviation, and combines the pre-charge voltage setting value, generator control parameters, and correction amount according to the amplitude limiting conditions to form the control calibration parameter group for the next pre-examination excitation. This application achieves real-time compensation for generator thermal drift and identification of cable parameters, avoiding calibration deviation problems caused by generator thermal losses.

[0106] This application also provides another embodiment, namely, a non-volatile computer-readable storage medium storing a program for a calibration method of an oscillating high voltage generator, which can be executed by at least one processor to perform the steps of the oscillating high voltage generator calibration method as described above.

[0107] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0108] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

Claims

1. An oscillating high voltage generator calibration method, characterized by, include: The thermal characterization parameters, pre-charge voltage, high voltage waveform, and loop current waveform of the excited cable are obtained. Based on the high voltage waveform and loop current waveform, the first peak voltage, the interval between adjacent peaks, and the attenuation characteristics are obtained. The product parameter between the total inductance and total capacitance of the oscillation circuit is determined based on the interval between adjacent peaks, and the total damping parameter of the oscillation circuit is determined based on the attenuation characteristics. Based on the thermal characterization of the generator, the preset generator reference parameters are thermally corrected to obtain the generator thermal parameters. Based on the product parameter, total damping parameter and generator thermal parameters, the oscillation circuit parameters are separated into cable parameters and generator parameters. The cable parameters include the cable equivalent capacitance and cable equivalent loss parameters. The equivalent capacitance of the cable is checked for energy storage safety. If the energy storage limit is not exceeded, the pre-charge voltage setting value for the next excitation is generated based on the equivalent capacitance of the cable. The generator control parameters for the next excitation are corrected based on the generator parameters. Based on the current first peak voltage deviation, a correction value is generated. The pre-charge voltage setpoint, generator control parameters, and correction value are then combined according to the limiting conditions to form the control calibration parameter group for the next pre-detection excitation.

2. The calibration method for an oscillating high-voltage generator according to claim 1, characterized in that, The thermal characterization of the excited cable is a temperature vector composed of sampled values ​​from multiple key monitoring points.

3. The calibration method for an oscillating high-voltage generator according to claim 1, characterized in that, The charging and discharging current in the circuit is obtained by a high-frequency current transformer installed on the return ground wire, and the circuit current waveform is generated.

4. The calibration method for an oscillating high-voltage generator according to claim 1, characterized in that, The product parameter between the total inductance and total capacitance of the oscillation circuit is determined based on the interval between adjacent peak values, including: Interval between adjacent peaks Substitute into the preset oscillation frequency calculation model Obtain the equivalent oscillation frequency of the oscillation circuit. ; Based on the equivalent oscillation frequency and the total inductance of the circuit and total capacitance Frequency constraint relationship between Establish the relationship between adjacent peak intervals, the product of total inductance and total capacitance. The mapping relationship is based on a preset formula. Calculate the product parameter of the total capacitance and total inductance of the circuit.

5. The calibration method for an oscillating high-voltage generator according to claim 1, characterized in that, Based on the generator's thermal characterization parameters, the preset generator reference parameters are thermally corrected to obtain the generator's thermal parameters, including: Acquire the instantaneous temperature field distribution sequence, shell thermal strain displacement data, and pressure pulse frequency from the thermal characterization parameters of the generator; The equivalent deformation of the winding structure is determined based on the thermal strain displacement data of the shell. The geometric distribution parameters of the winding are reconstructed based on the equivalent deformation to generate the initial corrected inductance value. The temperature drift compensation of the basic DC resistance is performed based on the instantaneous temperature field distribution sequence to generate the real-time internal resistance. The initial dielectric constant of the insulating medium is corrected based on the pressure pulse frequency to generate the parasitic capacitance correction amount. The initial correction inductance value, real-time internal resistance, and parasitic capacitance correction are input into the preset oscillation circuit model to generate a theoretical oscillation waveform. The theoretical oscillation waveform is then compared with the measured decaying oscillation waveform to obtain the residual result. Based on the residual results, the initial correction inductance value, real-time internal resistance, and parasitic capacitance correction amount are iteratively corrected to obtain the generator thermal parameters representing the current thermal operating characteristics of the oscillating high voltage generator.

6. The calibration method for an oscillating high-voltage generator according to claim 1, characterized in that, Obtaining the equivalent capacitance of the cable includes: An inductor-capacitor coupling model is established within the same hot sampling window based on the periodic constraint relationship of the oscillation circuit. The product parameter is correlated with the hot inductance value in the generator's hot parameters to determine the total equivalent capacitance of the oscillation circuit. Based on the geometric deformation vector and dynamic dielectric constant of the generator's hot parameters, the equivalent capacitance distribution model inside the generator is reconstructed, and the generator's capacitance contribution is calculated. The equivalent capacitance of the cable is obtained by subtracting the capacitance contribution from the total equivalent capacitance.

7. The calibration method for an oscillating high-voltage generator according to claim 1, characterized in that, Obtain the equivalent loss parameters of the cable, including: Based on the mapping relationship between the total damping parameter and the hot inductance value, the total damping parameter is converted into the total equivalent loss parameter. Based on the hot internal resistance value in the generator's hot parameters, the equivalent loss contribution of the generator is calculated. The equivalent loss contribution is then subtracted from the total equivalent loss parameter to obtain the cable's equivalent loss parameter.

8. The calibration method for an oscillating high-voltage generator according to claim 1, characterized in that, The pre-charge voltage setting for the next excitation is generated based on the cable's equivalent capacitance, including: The cable energy storage value corresponding to the candidate pre-charge voltage for the next excitation is calculated based on the cable's equivalent capacitance. The cable energy storage value is compared with the preset energy storage upper limit. When the cable energy storage value does not exceed the preset energy storage upper limit, the candidate pre-charge voltage is determined as the pre-charge voltage setting value for the next excitation. When the cable energy storage value exceeds the preset energy storage upper limit, the upper limit of the allowable pre-charge voltage is determined based on the cable's equivalent capacitance and the preset energy storage upper limit. The setting value of the pre-charge voltage for the next excitation is limited based on the upper limit of the allowable pre-charge voltage.

9. The calibration method for an oscillating high-voltage generator according to claim 1, characterized in that, The generator control parameters for the next excitation are corrected based on the generator parameters, including: after the pre-charge voltage setting value is determined, the generator control parameters are determined based on the offset relationship between the generator parameters and the preset generator reference parameters.

10. A calibration system for an oscillating high-voltage generator, used to implement the method according to any one of claims 1-9, characterized in that, include: The cable data acquisition module is used to acquire the thermal characterization parameters, pre-charge voltage, high-voltage waveform, and loop current waveform of the excited cable, and to acquire the first peak voltage, adjacent peak interval, and attenuation characteristics based on the high-voltage waveform and loop current waveform. The generator hot-state parameter acquisition module is used to determine the product parameter between the total inductance and total capacitance of the oscillation circuit based on the interval between adjacent peaks, and to determine the total damping parameter of the oscillation circuit based on the attenuation characteristics. Based on the thermal characterization of the generator, the preset generator reference parameters are thermally corrected to obtain the generator thermal parameters. The oscillation circuit parameter separation module is used to separate the oscillation circuit parameters into cable parameters and generator parameters based on the product parameters, total damping parameters, and generator thermal parameters. The cable parameters include the cable equivalent capacitance and cable equivalent loss parameters. The cable equivalent capacitance safety verification module is used to verify the energy storage safety of the cable equivalent capacitance. When the energy storage is within the limit, it generates the pre-charge voltage setting value for the next excitation based on the cable equivalent capacitance; and corrects the generator control parameters for the next excitation based on the generator parameters. The calibration parameter determination module is used to generate a correction amount based on the current first peak voltage deviation, and to combine the pre-charge voltage set value, generator control parameters and correction amount into a control calibration parameter group for the next pre-detection excitation according to the limiting conditions.

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