254 results about "Damping ratio" patented technology

The invention discloses a harbor shore power system oscillation damping suppression method based on heuristic probability optimization. According to the method, sliding window preprocessing is carried out on an alternating current bus side current time domain oscillation signal, modal decomposition is carried out based on a Prony algorithm, and modal energy is calculated to judge an oscillation mode; the discriminated oscillation modes are aggregated and mapped into equivalent circuit elements, a corresponding three-order circuit state matrix is constructed, and the damping ratio of each mode is determined according to the characteristic value of the matrix; taking a damping ratio as an evaluation index, introducing an influence factor to construct a multi-objective optimization function, parameterizing the parallel adjustable impedance, and limiting an adjustable range; and searching the control parameters by adopting a heuristic probability optimization strategy to obtain final damping control parameters, and downloading the final damping control parameters to the parallel adjustable impedance device to realize online dynamic adjustment. According to the method, multi-modal identification, physical magnitude mapping and online adaptive optimization can be realized, and the suppression capability and the operation stability of the shore power system on sub / super synchronous oscillation are improved.

The invention relates to the technical field of steel reinforced concrete vibration testing, and discloses a method and system for testing the vibration performance of a steel reinforced concrete frame structure, and the state of the steel reinforced concrete frame structure is judged through vibration amplitude and frequency changes under the conditions of different excitation modes, measurement point positions, sampling frequencies, collection durations and the like. By accurately measuring and analyzing the change of the damping ratio, potential damage or performance change of the structure can be found in time, and a powerful basis is provided for safety assessment and maintenance of the structure; the signal is decomposed and analyzed based on Hilbert-Huang transform, the internal composition and the change rule of the structure vibration signal can be analyzed more finely, and the method has advantages for identifying weak vibration characteristics and early damage signs of the structure in a complex stress state, so that the test structure can be evaluated in time in the early damage stage, and the test accuracy is improved. And therefore, coping treatment can be conveniently carried out.

The invention relates to a large-span bridge flutter critical wind speed prediction method based on an L-P perturbation method. The method comprises the following steps that S1, physical characteristics and aerodynamic parameters of a bridge are obtained through a wind tunnel test to serve as basic data; s2, establishing a bridge motion control matrix equation based on modal displacement; s3, deriving an explicit solution of the modal frequency, the damping ratio and the modal characteristic of each modal branch based on an L-P perturbation method; s4, iteratively solving the modal frequency, directly solving the damping ratio, the amplitude ratio and the phase difference on the basis, observing the change of the modal damping ratio xi in each direction along with the wind speed U, and determining the flutter critical wind speed; the problems that an explicit closed solution of an existing three-degree-of-freedom flutter starting condition needs to carry out multiple times of iterative calculation on modal frequency, damping ratio and vibration mode, the influence of structural parameters and pneumatic parameters on pneumatic instability is difficult to clearly explain, and the flutter critical wind speed of a large-span bridge cannot be well predicted are solved.

The invention discloses a wind turbine generator blade damage judgment method and detection system based on voiceprint detection, and belongs to the technical field of wind turbine generator blade detection. The damage judgment method comprises the following steps: acquiring environmental parameters of a wind power plant, and establishing a sound velocity correction model based on the environmental parameters; acquiring a blade resonance sound signal, and correcting the blade resonance sound signal based on the sound velocity correction model to obtain a blade resonance sound signal with a high signal-to-noise ratio; performing FFT spectrum analysis on the blade resonance sound signal with the high signal-to-noise ratio, identifying the peak position of the first three-order natural resonance frequency of the blade, and performing analysis to obtain the current modal frequency, damping ratio and sub-band energy distribution entropy value of the blade; historical baselines of the modal frequency, the damping ratio and the sub-band energy distribution entropy of the blade in the healthy state are obtained, and the modal frequency offset, the damping ratio change rate and the acoustic impedance spectrum entropy of the blade are obtained; and wind turbine generator blade damage determination is carried out by using a high-precision time difference detection technology.

The invention discloses a VSG virtual inertia and damping coefficient feasible region analysis, design and application method and device, and relates to the field of power system analysis processing, and the method comprises the steps: employing a VSG frequency stability analysis model to determine a frequency stability index, a virtual synchronous generator power constraint and an energy index constraint based on physical parameters, depicting a basic feasible region, and determining a frequency dynamic damping ratio and a time constraint; depicting a feasible region based on the basic feasible region in combination with a frequency dynamic damping ratio and a time constraint; and based on the customized dynamic performance requirement, determining whether the feasible region meets the feasible region existence condition, if so, taking the feasible region as a finally designed feasible region, and if not, adjusting the physical parameters, and carrying out feasible region analysis and design again. According to the invention, the problem that the fixed inverter parameters cannot meet the dynamic requirements of the system can be solved, and the problem that the system stability is poor after the static power generation unit is connected to the power grid can be effectively solved.

The invention provides a damping ratio identification method and device, electronic equipment and a storage medium, and is applied to the technical field of civil engineering structures, and the method comprises the steps: obtaining a free attenuation signal generated by a target civil engineering structure; determining a front attenuation signal and a rear attenuation signal according to the free attenuation signal; calculating the front attenuation signal according to Fourier transform to obtain a front power spectrum, and calculating the rear attenuation signal according to Fourier transform to obtain a rear power spectrum; determining a natural vibration frequency and a front power spectrum amplitude according to the front power spectrum, and determining a natural vibration frequency and a rear power spectrum amplitude according to the rear power spectrum; and according to the natural vibration frequency and the front power spectrum amplitude corresponding to the modal peak value of the front attenuation signal of each order and the natural vibration frequency and the rear power spectrum amplitude corresponding to the modal peak value of the rear attenuation signal of each order, identifying the damping ratio corresponding to the modal of each order. According to the method, the complexity of a calculation process is reduced, and the precision and accuracy of a modal damping ratio identification result are improved.

The invention belongs to the field of structural modal identification, and particularly relates to an automatic modal parameter identification method based on a multi-scale space, which comprises the following steps: collecting a vibration data sample from a target structure, the vibration data sample comprising an acceleration signal of the structure; selecting power spectrum calculation parameters including a window function and a fast Fourier transform (FFT) length; performing frequency spectrum estimation on the acceleration signal by using interpolation power spectrum estimation to obtain frequency spectrum data; analyzing the spectrum data by using a multi-scale space algorithm, and detecting a peak value in the spectrum data to obtain a peak value frequency; through a frequency domain decomposition method, according to the peak frequency, modal parameters of the structure are calculated, the modal parameters comprise the modal frequency and the damping ratio, interpolation power spectrum estimation and a multi-scale space algorithm are innovatively combined, automatic and accurate identification of the modal parameters is achieved, and the identification precision and efficiency are remarkably improved.

The invention discloses a vibration control method for lifting construction of a target object, and the method comprises the steps: measuring the height of the target object at any moment, determining the mass of a damping box body, and determining the optimal frequency ratio and the optimal damping ratio of a TMD and a bearing structure based on the mass of the damping box body, the TMD comprises the damping box body and a lifting device used for lifting the damping box body, the bearing structure comprises a lifting target object and a distance measuring device for measuring the height of the target object, the suspension length of the damping box body is determined based on the height of the target object under the condition that the optimal frequency ratio and the optimal damping ratio serve as constraint conditions, and the damping box body is lifted according to the suspension length, so that the damping box body is lifted at the moment t; the suspension length of the damping box body is matched with the height of the target object so as to eliminate or weaken the vibration influence. In the construction process of lifting the target object, vibration, caused by wind loads, of the target object can be eliminated or weakened, and the construction safety is improved.

The invention belongs to the technical field of working modal analysis, and discloses a current-carrying pipeline complex modal parameter identification method and system. The method comprises the following steps: acquiring vibration responses of a plurality of measuring points on a current-carrying pipeline under load excitation; calculating a vibration response correlation function of each measuring point and the reference point; decomposing the vibration response correlation function into a series of independent intrinsic mode functions by using variational mode decomposition; dividing the intrinsic mode functions into two types: intrinsic mode functions with variable amplitude and constant amplitude; eliminating an intrinsic mode function with a constant amplitude, and establishing an intrinsic mode function matrix; performing Hilbert transformation on the intrinsic mode function matrix, and combining the intrinsic mode function matrix with a Hilbert transformation matrix thereof to obtain a signal analysis matrix; and identifying the amplitude and the phase of the complex modal shape of the current-carrying pipeline and the inherent frequency and the damping ratio of the current-carrying pipeline based on the signal analysis matrix. According to the invention, the complex mode parameters of the current-carrying pipeline in the operation state can be identified.

The utility model discloses a damping performance testing device for a particle damper, which is characterized in that a fixed end of a particle damper mounting substrate of the testing device is arranged on a fixed bracket, and a free end of the particle damper mounting substrate is arranged far away from the fixed bracket; an excitation unit is used for being connected with an excitation input point of a particle damper mounting substrate so as to send an excitation signal to the particle damper mounting substrate; a detection unit is arranged on a particle damper mounting substrate and is used for detecting acceleration change generated by an excitation signal; the control unit is used for obtaining a first modal damping ratio of the particle damper mounting substrate and a second modal damping ratio after the particle damper to be tested is placed according to a vibration frequency response curve obtained by the acceleration change. By applying the scheme, the first modal damping ratio and the second modal damping ratio are compared, so that the test precision can be effectively improved, and a good technical guarantee is provided for evaluating the damping performance of the particle damper.

The invention discloses a dynamic and static testing device and method for a flexible pressure sensor, and relates to the technical field of sensor testing. The dynamic and static testing device for the flexible pressure sensor comprises a bracket, a pressure applying mechanism, a pressure applying head assembly, a pressure applying head support frame, a sample seat and a control system, the pressure applying mechanism outputs air pressure to the pressure applying head assembly through cooperation of the vibration exciter and the air pressure rod, so that a flexible film in the pressure applying head assembly deforms and further provides pressure applying pressure for a to-be-tested sample in contact with the flexible film; controllable electric signals including constants, lines, trigonometric functions or mutual combination are conveyed to the vibration exciter through the control system, and the electric signals can be converted into corresponding pressure waves through the vibration exciter and are applied to the sample to be tested, so that multi-waveform and multi-mode self-defined pressure waves are output to the sample to be tested; and dynamic parameters such as frequency response, resonant frequency and damping ratio of the flexible pressure sensor can be accurately tested.

The invention discloses an ultrasonic welding quality online detection system and method, and belongs to the technical field of laser non-contact measurement. According to the invention, the laser vibration measurement probe is rigidly coupled to the welding head to construct a follow-up-common-optical-path measurement unit, so that synchronous acquisition of vibration signals with zero mass loading is realized; further extracting an attenuation section after welding is finished from the signal, and inverting an equivalent modal damping ratio representing an interface energy dissipation state based on an exponential attenuation model; meanwhile, multi-dimensional physical indexes such as an energy transfer efficiency index Itrans and an input stability index Iin are calculated, and in combination with an energy absorption state index, collaborative fusion is carried out through a weighted fusion formula to obtain a comprehensive quality score; and finally, realizing quality attenuation early warning based on time sequence trend analysis of a scoring sequence. On-line sensing of the deep dynamic state in the welding process is achieved, the early defect recognition sensitivity and the system anti-interference capacity are remarkably improved, and the predictive maintenance capacity of quality degradation is achieved.

The invention relates to a hybrid damping swing structure design method and system, and the method comprises the following steps: analyzing an uncontrolled model of a floor, adding a damping ratio to the uncontrolled model, and carrying out the trial calculation to determine a target damping ratio; speed type energy dissipation devices are preliminarily arranged in the floor, and the parameters or the number of the speed type energy dissipation devices are adjusted so that the additional damping ratio can meet the target damping ratio; a swing column is arranged, supports are arranged on the periphery of the swing column, and support arrangement parameters are adjusted; extracting the most unfavorable working condition axial force of the support in small earthquakes and medium earthquakes, and arranging the buckling restrained support; and performing large-earthquake elastic-plastic analysis on the hybrid damping controlled model of the floor, judging whether the additional damping ratio is an optimal solution, optimizing the energy dissipater, and judging whether the structural index and the bearing capacity of the component of the hybrid damping controlled model meet the requirements to obtain the hybrid damping swing structure. Compared with the prior art, the self-resetting target of the structure after an earthquake and the recoverability of the structure function are achieved.

The present disclosure introduces a multi-panel structure designed to effectively attenuate sound transmission. The structure comprises a series of panels and absorbers arranged alternately. The panels are constructed from continuous and uninterrupted materials, with at least one panel incorporating a meta-material possessing metallic substance and specific properties. The absorbers feature porous materials with solid and fluid components, and in some cases, may also include meta-materials with solid and fluid components. The panels and absorbers possess optimized characteristics for sound attenuation, such as average bulk density, elastic modulus, and the damping ratio. Recycled materials can be utilized, promoting environmentally friendly construction without compromising sound-blocking capabilities. Additionally, the present disclosure further comprises a computer-implemented method utilizing artificial intelligence models for designing multi-panel structures and a computer simulation method for generating internal structures and compositions to attenuate sound transmission. This innovative solution provides an efficient approach to soundproofing applications.

The invention provides a damping method for stay cables and a main beam based on damper mounting positions, which comprises the following steps of: establishing a finite element model about the main beam and each stay cable, and performing modal analysis on the finite element model to obtain a vibration mode of each stay cable and a vibration response characteristic of the main beam; aiming at the target stay cable, determining a standard mounting interval of an external damper arranged between the target stay cable and the main beam; in the standard installation interval, the additional damping ratios of the main beam at different positions are calculated by adjusting the position of the external damper and combining the vibration amplitude change of the main beam, and the maximum value of the additional damping ratios of the main beam is selected as a target installation position; according to the step of determining the target installation position of the target stay cable, the target installation position corresponding to each external damper is obtained, and the external dampers are arranged according to the corresponding target installation positions. The installation positions of the external dampers between the stay cables and the main beam are determined, and vibration of the main beam and the stay cables is relieved most effectively.

The invention discloses a passivity-based weak power grid phase-locked loop parameter adaptive optimization method, which comprises the following steps of: (1) establishing a dynamic coupling model of a phase-locked loop and a converter system under a weak power grid condition, and analyzing an influence mechanism of phase-locked loop parameters on system stability; (2) deriving a real-time calculation method of the equivalent short-circuit ratio of the system based on a passivity theory, and constructing a short-circuit ratio-parameter sensitivity relation matrix; and (3) adaptively adjusting the bandwidth coefficient and the damping ratio parameter of the phase-locked loop by dynamically sensing the change of the short-circuit ratio of the power grid, and eliminating the harmonic oscillation or instability risk caused by the fixed parameter. According to the method, stable operation of the system under the full working condition is ensured, and the dynamic stability and robustness of the wind turbine generator under the low-short-circuit-ratio weak-power-grid working condition can be remarkably improved.

The invention provides a bearing outer ring fault diagnosis test parameter setting optimization method, which comprises the following steps of: firstly, accurately acquiring structural parameters of a bearing by utilizing a measuring tool; secondly, testing and calculating the inherent frequency and the damping ratio of the bearing in the installed state through a modal experiment; selecting test working condition parameters according to the actual operation environment of the bearing, and calculating the fault characteristic frequency of the bearing; bearing fault simulation signal band-pass filtering processing is constructed; meanwhile, constructing a fault signal equivalent model; carrying out resonance demodulation analysis on the equivalent model, extracting an envelope spectrum and evaluating a fault diagnosis effect; and finally, circularly adjusting working condition parameters, iteratively optimizing the test working conditions, and selecting the working condition with the maximum fault characteristic frequency amplitude and the minimum noise interference as the optimal test condition. According to the invention, the accuracy and reliability of bearing outer ring fault detection are effectively improved, and powerful support is provided for fault diagnosis of mechanical equipment.

The invention belongs to the technical field of low-frequency vibration control, and discloses a low-frequency low-damping tuned mass damping device which is mainly composed of a rigid support, a first sling, a rotating arm, a cable hole, a first arc guide groove, a second arc guide groove, a lock pin, a second sling, a first mass block, a spring, a second mass block and a damping element. The flexible suspension rotation replaces the bearing or ball screw support, so that the damping is obviously reduced; the long rotating arm is combined with the equivalent large-diameter arc guide groove, so that the low-frequency low-damping tuned mass damping device can achieve large vertical displacement at a small rotating angle, and damping is reduced. The low-frequency low-damping tuned mass damping device innovatively adopts double-mass-block configuration, so that static force borne by a spring is generated by mass difference, and static deformation of the spring is remarkably shortened. According to the method, low-frequency operation can be achieved under the condition that the space is limited, the low-damping characteristic is kept, it is guaranteed that the requirement for the optimal damping ratio is met, and therefore a new technical approach is provided for control over low-frequency vortex vibration of a large-span bridge.

The invention discloses a zero-damping magnetic suspension wind tunnel segment model test device, and relates to the technical field of bridge wind resistance experiments, the zero-damping magnetic suspension wind tunnel segment model test device comprises a segment model, a laser displacement meter, an adjusting device and a guide rail device, the adjusting device comprises a damping adjusting device and a magnetic suspension adjusting device, the damping adjusting device is connected with four corners of the segment model, the magnetic suspension adjusting device is arranged below the segment model, the damping adjusting device is connected with the guide rail device in a clamping manner, and the guide rail device is fixed on a top plate and a bottom plate of a wind tunnel laboratory. Magnetic suspension replaces traditional spring suspension, zero-damping suspension of the segment model in a wind tunnel test is achieved, and therefore dampers can be flexibly arranged according to test requirements, and the test damping ratio can be adjusted in a stepless mode; in addition, according to the testing device, the section proportion of the supporting device is greatly reduced, interference to airflow is smaller, and the quality of an obtained wind field is better.

The invention provides a bridge vortex-induced vibration and flutter control TMDI parameter optimization method, which comprises the following steps of: according to a selected inertia mass ratio, obtaining optimal values of parameters under a control target by adopting a GBO optimization algorithm, wherein the optimal values are a TMDI mass ratio, a frequency ratio and a damping ratio; according to the optimization algorithm, the target function Fs converges to the minimum individual, namely the minimum TMDI mass ratio, and the minimum TMDI mass ratio and the corresponding optimal parameter, namely the optimal combination parameter. The invention further provides equipment, a storage medium and a program product. Compared with the prior art, the method has the advantages that the most economical TMDI optimization parameters can be obtained while effectiveness and robustness are considered.

The invention discloses a parameter adaptive control method and device of a virtual synchronous generator and electronic equipment, and relates to the technical field of voltage control. The method comprises the following steps: constructing an adaptive DC voltage droop coefficient function according to a coupling value of a DC voltage change frequency band of the multi-terminal flexible DC system in an operation process; calculating a damping ratio of an output port of the multi-terminal flexible DC system according to the DC voltage droop coefficient, and constructing a first optimization objective function according to the damping ratio of the output port and a preset damping ratio; constructing a second optimization objective function according to the differential mode frequencies of the plurality of converter stations of the multi-terminal flexible direct current system; and according to the small signal model of the multi-terminal flexible direct current system, the first optimization objective function and the second optimization objective function, constructing a parameter adaptive function, and solving the parameter adaptive function to obtain a target parameter value of the virtual synchronous generator. The technical problem that in the prior art, a multi-terminal flexible direct current system is poor in stability when facing disturbance is solved.

The invention discloses a PLC-based high-pressure-ratio magnetic suspension centrifugal heat pump control method and system, and the method comprises the steps: carrying out the self-adaptive sampling rate adjustment through collecting operation data and PLC configuration information, generating a dynamic signal matrix, recognizing a key pressure ratio control loop, and extracting vibration envelope and surge precursor frequency to generate early warning characteristic parameters; reversely adjusting the rigidity damping ratio of the magnetic bearing to determine an anti-surge protection boundary; fin temperature difference detection information is monitored, a partition defrosting map is generated through asymmetric frosting rate analysis, and minimum energy consumption analysis is executed to determine a reversing valve switching time sequence; performing operation characteristic and oil-gas migration coupling analysis to generate oil-gas separation optimization parameters, adjusting a magnetic suspension gap to extract a zero-power-consumption suspension interval, and constructing layered energy-saving control configuration; a preventive maintenance time window is generated through magnetic bearing current ripples, a fault-tolerant degradation operation mode and a self-adaptive control strategy are established, a heat pump control instruction is finally generated, and intelligent control over the high-pressure-ratio magnetic suspension centrifugal heat pump is achieved.

The invention provides a blade fault diagnosis method and device based on vibration of a wind generating set, and relates to the technical field of blade fault diagnosis of vibration of the wind generating set. The first-order modal frequency and damping ratio of the blade under different working conditions are accurately recognized through phase compensation and frequency response function calculation, modal parameters of a plurality of working condition points are connected in sequence to construct a dynamic response track, and a local mode feature vector is formed by calculating relative vectors of each point and other points in the track. And further integrating into a global mode feature matrix, obtaining a trajectory mode deviation index by calculating the Frobenius norm of the to-be-monitored matrix and the reference matrix, and judging the structural damage according to the statistical law that the index continuously exceeds the threshold.

The invention discloses a bridge modal parameter identification method based on random subspace and biaxial vehicle response, belongs to the technical field of bridge health detection, and solves the problem of precision misalignment when a traditional indirect detection method synchronously identifies the inherent frequency, vibration mode and damping ratio of a bridge. And the technical bottleneck that the modal shape is easily interfered by bridge damping is overcome. The method comprises the following steps: eliminating vehicle frequency interference based on a double-axle vehicle-bridge contact point response algorithm, identifying the frequency and damping ratio of a bridge of detection data by using a random subspace method, and identifying a bridge modal shape by using a spatial relationship between front and rear contact point responses; contact point response signals are obtained through a double-axle vehicle-bridge contact point response algorithm, interference of vehicle frequency can be effectively removed, front and back contact point response signals are processed through a random subspace method, the accurate frequency and damping ratio of a bridge can be obtained, and when the vibration mode of the bridge is recognized, the vibration mode of the bridge is recognized. And the influence of bridge damping on bridge vibration mode identification can be effectively eliminated.

The invention belongs to the field of structural wind-induced vibration control, and relates to a design method of a novel tuned liquid damper with an inerter, which comprises the following steps: S1, respectively determining the mounting floors of a TLD device and an inerter device according to the design of a main body structure; s2, designing the effective mass, the shaking frequency and the damping ratio of the TLD according to the dynamic characteristic parameters of the controlled structure; s3, the geometric dimension and the water storage height of the TLD are designed in combination with the structural plane shape and the space limitation of the floor where the TLD is located; s4, designing an inerter coefficient beta of the inerter device in combination with the mass of the main body structure; s5, calculating the rigidity K of the linear spring element connected with the TLD and the damping coefficient C of the damping element; s6, establishing a main body structure-TLDI system motion equation, and calculating the vibration response and the vibration reduction rate of the main body structure; and S7, judging whether the novel tuned liquid damper (TLDI) with the inerter can enable the controlled structure to achieve an ideal control effect or not. Compared with TLCDI and TMDI devices of the same type, the TLCDI and TMDI device has superiority in economy and space utilization rate.

The invention discloses a device and method for testing the dynamic compression modulus and damping ratio of a soil body under the cyclic load effect of seismic compression waves, and belongs to the technical field of geotechnical tests. The loading mechanism is arranged on the bearing platform and is used for applying a dynamic load to the sample; the fixing mechanism is arranged on the loading mechanism and is used for fixing the sample; the drainage mechanism is arranged on the fixing mechanism and is used for draining internal water in the process of applying the back pressure and saturating the sample; and the computer is respectively connected with the loading mechanism and the drainage mechanism and is used for controlling the loading mechanism and the drainage mechanism to operate. The dynamic lateral confinement compression modulus of the soil body is tested through the combination of the cyclic lateral confinement compression and the piezoelectric ceramic crystal oscillator, and the problem that the dynamic characteristics of the soil body caused by vertical seismic actions are not tested by using a laboratory method at present is solved.

The present application provides a kind of transmission conductor negative stiffness damper, provides damping by another connection damper, negative stiffness device increases damping ratio, realizes conductor model damping effect;Main components are arranged side by side by fixed magnet and movable magnet, the interaction force between its magnets is basically linear increase, that is, it can guarantee constant negative stiffness value, damping effect is obvious and model loss is small, and durability is strong;Light weight, convenient transportation, easy to install and maintain;Transmission conductor negative stiffness damper is rigidly connected with insulator string as a whole, and can effectively transmit the vibration of conductor galloping;The present application is novel and unique in design, has wide range of application, and has good popularization and application value and economic benefits.

The application discloses an inverter power three-phase short-circuit fault current analytic method considering a phase-locked loop and a current inner loop transient process, and belongs to the technical field of photovoltaic grid-connected system fault analysis. The application studies the transient process of SRF-PLL under different damping ratios, analyzes the influence of the transient process of SRF-PLL on the coordinate transformation of PCC point voltage and current, finally considers the influence of the transient process of SRF-PLL and the current inner loop on the fault current, introduces a correction coefficient, and decomposes the phase current component expressions of the inverter port fault current into the phase current components of the inverter port current under the first influence condition and the phase current components of the inverter port current under the second influence condition. Through the application, the transient characteristics of the IIDG can be more accurately analyzed, the short-circuit characteristic analysis of the IIDG is perfected, and a reference basis is provided for the fault characteristic analysis of the IIDG.

This invention discloses a method for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics. The method includes: independently acquiring wind pressure and vibration displacement signals from the structural surface; integrating the wind pressure signal to obtain the self-excited aerodynamic time history; identifying the vibration frequency and the total system damping ratio from the displacement signal; filtering the aerodynamic time history to extract the fundamental frequency component; establishing an analytical relationship between the aerodynamic out-of-phase component coefficient and the total system damping based on the structural dynamic equilibrium principle; and iteratively shifting the aerodynamic time history using the displacement signal as a reference until the out-of-phase components satisfy the analytical relationship, thereby determining and correcting the system delay. This invention also discloses a system and storage medium for correcting the phase difference between aerodynamic and displacement signals in wind tunnel tests based on self-excited vibration characteristics. This invention requires no additional hardware and can accurately compensate for electrical triggering and physical transmission delays, effectively improving the reliability of aerodynamic parameter identification.

The application discloses a new energy base phase modifier synchronous instability analysis method and system, and belongs to the technical field of power system stability analysis. The method comprises the following steps: obtaining a training data set covering multi-dimensional power grid parameters and fault scenes, calculating dominant degree factors based on the coupling dynamic index of inverters, and dividing multiple dominant degree factor intervals to represent the control dominance of different types of inverters; a risk guardrail set containing a power coupling index and a damping ratio change amount is constructed, and a differentiated threshold is set for each interval; the control parameters of the inverters are extracted and a candidate boundary line set is generated, the performance of the candidate boundary line set is evaluated through transient simulation, the priority value is calculated by comprehensively considering the deployable proportion, the time benchmark ratio and the safety coefficient, and the optimal target boundary line is selected; finally, the target boundary line parameters are mapped into adaptive control gears, and the coordinated control of the phase modifier and the inverter is realized in combination with the real-time risk state, so that the synchronous instability risk is effectively inhibited.