67 results about "Frequency oscillation" patented technology

The invention relates to the technical field of power system operation and control, and discloses an improved model-free adaptive flexible low-frequency power transmission oscillation suppression method, which performs zero-phase lag filtering on noisy signals through a nonlinear tracking differentiator, effectively solves the problem of control divergence caused by signal noise, and improves the suppression efficiency. A tight-format dynamic linearization and linear expansion state observer technology is adopted, accurate capture of dynamic characteristics of a strong nonlinear system and real-time observation and compensation of internal and external full-dimensional disturbance are achieved without dependence of a physical model, and particularly, an adaptive estimation algorithm of an output variable quantity penalty factor is introduced. The problem that model parameter identification jumps severely under the broadband oscillation working condition is solved, the robustness of a control system is enhanced, and the self-adaptive optimality of a control strategy is guaranteed and interference of long-term online operation on steady-state performance is avoided by combining parameter optimization of a cuckoo search algorithm and an event triggering mechanism of time-frequency double criteria.

The embodiment of the invention discloses a negative damping elimination method, device and equipment based on SVG and a storage medium, and the method comprises the steps: carrying out the impedance scanning of the SVG in a range of 1-3000Hz, obtaining the positive-sequence impedance and negative-sequence impedance of the SVG under different operation conditions, and determining the leading operation condition of the SVG impedance; determining the positive sequence equivalent impedance and the negative sequence equivalent impedance of the SVG grid-connected point according to the positive sequence dominant impedance and the negative sequence dominant impedance of the SVG under the dominant operation condition; determining the value ranges of the positive sequence damping correction value and the negative sequence damping correction value of the SVG; the maximum value of the intersection of the two value ranges is determined as SVG compensation damping, and the SVG compensation damping is merged into an SVG grid-connected point port; according to the scheme, only two unknown parameters including the positive sequence damping correction value and the negative sequence damping correction value are involved, the parameters can be calculated based on an analytic formula pure algebraic equation, the calculation mode is simple, the port impedance characteristic negative damping of the SVG in the full frequency band within the range of 1-3000 Hz can be eliminated, and the problem of high-frequency oscillation is thoroughly solved.

This invention discloses a method for locating epileptogenic zones based on high-frequency oscillations and connectivity, comprising the following steps: 1. Acquiring SEEG data and selecting representative channels; 2. Filtering to acquire 54-200Hz signals and selecting baseline and target data; 3. Acquiring normalized high-frequency energy; 4. Calculating time and energy coefficients to obtain a high-frequency epileptogenicity index; 5. Filtering to acquire 12-45Hz signals; 6. Calculating nonlinear regression analysis; 7. Calculating total intensity; 8. Defining and calculating the connectivity high-frequency epileptogenicity index and evaluating performance. This invention can accurately locate epileptogenic zones in patients with different seizure patterns, and has potential application value in epilepsy treatment.

The present application relates to the technical field of power system stability control, and particularly relates to a high-proportion wind power access system wide-frequency oscillation suppression method based on impedance shaping. The content comprises: constructing a frequency domain output impedance matrix, extracting a dominant wide-frequency oscillation coupling mode frequency band, introducing a mode suppression driven impedance shaping compensation mechanism, constructing a mode suppression driving quantity based on the mode direction in the dominant wide-frequency oscillation coupling mode, and performing local impedance shaping on the output impedance; based on the mode suppression driving quantity, quantifying the mode interference sensitivity between wind power converters, and introducing an impedance shaping gain correction mechanism based on the mode interference sensitivity, to correct the target output impedance after local shaping. The problems that the shaping process cannot effectively adjust dynamically according to the equipment capacity of the wind power converter and the frequency risk, resulting in no difference shaping and excessive compensation, and the problems that the interference coupling between the wind power converters cannot be effectively suppressed, resulting in excessive oscillation or suppression are solved.

The application provides a kind of energy storage converter control system stability analysis method, the method will model predictive control as the virtual synchronous generator control upper control system of energy storage converter, will model predictive control output value as the active power, reactive power reference value of virtual synchronous generator.This application realizes real-time correction virtual synchronous generator power, improves the stability of control system, avoids frequency oscillation.

The application discloses a kind of power system low-frequency oscillation characteristic signal extraction methods, comprising: the electrical variation data of acquisition each generator outlet is preprocessed;Through complementary ensemble empirical mode decomposition, variation data is decomposed, and noise component is filtered out;SPA smoothing algorithm is used to process the electrical variation signal after denoising;Prony method is used to decompose the signal after smoothing, and the amplitude and phase of each frequency component are extracted;The application has more excellent noise suppression capability and signal fidelity, can effectively solve the problem of modal aliasing, can adaptively identify and filter out various noise components, and shows good adaptability to noise interference under different operating conditions of power system;SPA smoothing algorithm reduces the error introduced by complementary ensemble empirical mode decomposition while effectively retaining the key features of low-frequency oscillation;Combined with Prony method, the characteristic parameters of the oscillation signal can be accurately extracted in a strong noise environment, providing a reliable data basis for low-frequency oscillation source identification.

The invention discloses a method and a device for positioning a low-frequency oscillation source of a wind-thermal bundling system. The method comprises the following steps: acquiring multi-source signals of the wind-thermal bundling system; carrying out adaptive wavelet threshold anti-noise preprocessing; carrying out adaptive noise intensity set empirical mode decomposition; screening a wind-fire coupling key mode; calculating a wind-fire adaptive dissipated energy flow; and oscillation source determination based on phase coupling: constructing a multi-condition fusion determination logic in combination with a phase coupling relationship between a dissipated energy flow trend and a wind-fire key mode and a phase coupling relationship between the dissipated energy flow trend and an electric energy transmission signal so as to realize oscillation source type identification. According to the invention, accurate identification of oscillation sources (a wind power side, a thermal power side and a tie line) in a frequency band of 0.1-2Hz is realized, and both positioning accuracy and engineering real-time performance are considered.

This invention discloses a method and system for frequency oscillation transfer analysis under multi-machine islanding. The method includes: establishing a transfer function; substituting the operating parameters of each operating condition into the transfer function; if stable, determining whether it is stable; if stable, it indicates that the system on the second VSG side is stable; if unstable, jumping to S3.1 to determine the cause of frequency oscillations on the second VSG side and the first VSG side; if unstable, it indicates that the frequency oscillations on the second VSG side are caused by insufficient stability margin of the second VSG side itself. The advantage of this invention is that it more accurately explains the cause of low-frequency oscillations in the system, thereby guiding the design of virtual synchronous machine controller parameters.

The invention discloses a measurement regulation and control method and system of an atomization tester, and aims to solve the problem that a Peltier temperature control system is easy to generate overshoot and low-frequency oscillation at a critical point. The method comprises the following steps: S1, setting a target temperature and a precision tolerance interval; s2, rapidly cooling to a dynamic switching temperature; s3, switching to a precise approaching mode, and driving a Peltier by adopting a frequency self-adaptive micro-current pulse sequence based on the residual heat to realize overshoot-free temperature positioning; and S4, when the temperature meets the steady-state conditions of the mean value, the standard deviation and the trend slope, switching to a steady-state holding mode, performing spectral analysis on the temperature sequence to distinguish high-frequency disturbance and low-frequency drift, and only applying intelligent micro-compensation subjected to nonlinear filtering to the low-frequency drift. According to the invention, through multi-stage strategy matching, pulse control based on energy prediction and intelligent disturbance identification, rapid, accurate and stable control of the temperature of the condensation plate is realized, and the reproducibility of a test result is significantly improved.

The invention discloses a thermal power generating unit low-frequency oscillation fault diagnosis method and system based on multi-source data analysis, and mainly relates to the technical field of thermal power generating unit fault diagnosis. Comprising the steps that a multi-source signal acquisition network is constructed, multi-source unit operation sensing of a preset monitoring window is executed on a target thermal power unit, and a speed regulator oil pressure pulsation sequence, a shaft system torsional vibration angular displacement sequence, a boiler heat storage coefficient sequence and a power grid power angle sequence are obtained; cascade time-frequency analysis is carried out; performing joint frequency matching and mode identification to obtain a plurality of abnormal low-frequency oscillation modes; and performing fault scene diagnosis on the plurality of abnormal low-frequency oscillation modes to obtain a target diagnosis result. The low-frequency oscillation fault diagnosis method has the beneficial effects that the technical problem of high error rate of low-frequency oscillation fault diagnosis caused by lack of reliable analysis of signals in the prior art is solved, and the technical effect of improving the fault diagnosis accuracy is achieved.

The application discloses a wide-frequency oscillation monitoring method and system based on waveform data. First, the coherent spectrum analysis is carried out on the waveform data of each node of the system collected by the wide-area measurement system. The oscillation is judged by detecting the coherent spectrum peak value. If it is judged that the oscillation occurs, the oscillation sample is input into the CNN model. The number of data is compressed through the convolution layer and the pooling layer. The oscillation characteristics are extracted. The overfitting is reduced. The full connection layer is used to summarize and output the feature data set D. Finally, the oscillation characteristics of the wide-frequency oscillation signal output by the convolution neural network are used as the input of the XGBoost. The oscillation frequency and the attenuation factor are identified. The application greatly reduces the monitoring cost, solves the online monitoring problem of the oscillation signal in the wide-frequency range, discriminates the oscillation and the noise by using the coherent spectrum of the multi-node waveform data, effectively reduces the misjudgment caused by the strong noise, constructs the CNN in an unsupervised manner, omits the setting of the label quantity, and improves the generalization ability and the calculation efficiency of the model.

This invention discloses a method and system for suppressing broadband oscillations in power systems based on improved virtual impedance. The method includes the following steps: acquiring grid-side and DC-side operating signals and converter output signals from the power system, and obtaining digital signals after preprocessing; performing spectral analysis on the digital signals to extract oscillation frequency characteristics, determining the current oscillation type in the power system, and outputting corresponding control signals; switching the operating mode of the filter in the dual-mode bandpass filter; outputting the corresponding oscillation component; matching and calling a pre-tuned virtual impedance parameter model, and generating virtual impedance amplitude and phase adjustment commands; converting the virtual impedance into a converter drive signal to regulate the converter output impedance characteristics and suppress broadband oscillations. This invention, through oscillation type identification and coordinated switching of two types of dual-mode filters, can regulate the converter output impedance without additional hardware, effectively suppressing broadband oscillations in the power system.

The invention belongs to the technical field of air compressor efficiency evaluation, and provides an air compressor efficiency evaluation method and system based on decline trend prejudgment, and the method comprises the steps: comprehensively judging whether the high-frequency oscillation of an efficiency signal is caused by a rotating stall cluster or not through the time domain analysis and judgment of high-frequency periodic oscillation and the frequency domain judgment of a characteristic peak; if yes, performing dual-band division of a stall mass oscillation characteristic band and an efficiency decline low-frequency characteristic band; the method comprises the following steps: acquiring a compressor efficiency oscillation and decline composite signal, performing wavelet packet decomposition according to divided dual bands, removing decomposed oscillation characteristic frequency band signals, only retaining efficiency decline characteristic frequency band signals, and reconstructing an oscillation-interference-free pure efficiency decline trend curve through spline interpolation and moving average; and on the basis of the pure efficiency decline trend curve, fitting calculation analysis of the linear / nonlinear decline rate is conducted, and judgment of the efficiency decline trend of the gas compressor is achieved in combination with pure efficiency decline trend curve morphological analysis.

The invention provides a transient simulation modeling method and system for intermediate frequency oscillation of a converter station, and belongs to the technical field of transient simulation and modeling of a power system. Comprising the steps that an alternating current filter bank model is established, and an arc channel Cassie-Mayr model in the breakdown process is introduced; based on the geometric parameters of the converter station grounding network, calculating the port impedance characteristics of the converter station grounding network in a middle frequency band, and constructing a lumped parameter equivalent circuit consistent with the impedance characteristics in the middle frequency band as the intermediate frequency grounding network equivalent model; in the electromagnetic transient simulation platform, connecting the alternating-current filter bank model, the intermediate-frequency grounding network equivalent model, the converter transformer and the alternating-current power grid model by using a connecting conductor to obtain a transient simulation model of the intermediate-frequency oscillation of the converter station; and performing simulation by using the transient simulation model of the converter station intermediate frequency oscillation, performing model verification and correction by combining measured data, and enabling a difference value between a simulation result and the measured data to be within a preset error range by adjusting parameters.

The invention belongs to the field of power system frequency modulation, and particularly discloses an electric hydrogen production frequency modulation system frequency control method based on model predictive control. According to the method, the prediction model is established based on the dynamic characteristics of the electrolytic cell power, so that the frequency and inertia of the next moment can be predicted according to the current state, and the influence of the power hysteresis characteristic is quantified; based on the prediction result, the additional frequency modulation power at the next moment is optimized and solved by utilizing a multi-target cost function to comprehensively plan frequency deviation, inertia back-compensation, a droop coefficient and the like, and the core is to convert prediction information into an optimized decision so as to actively compensate the lag effect and coordinate multiple control targets; and finally, according to the optimization decision, an accurate power control signal is generated and executed, so that the power regulation of the electrolytic cell can accurately match the real-time frequency support requirement of the system. Compared with the prior art, the problem of control mismatch caused by insufficient consideration of the power lag characteristic is solved, so that the frequency oscillation of the power grid is effectively suppressed.

The invention discloses a method and a system for suppressing broadband oscillation in a wind power grid-connected system. The method comprises the following steps: acquiring a current broadband impedance characteristic of the wind power grid-connected system at a preset grid-connected point; judging whether the wind power grid-connected system has a broadband oscillation mode or not based on the broadband impedance characteristic; in response to a broadband oscillation mode existing in the wind power grid-connected system, identifying one or more dominant oscillation frequency points, and executing adaptive double-loop oscillation suppression control to suppress oscillation corresponding to the one or more dominant oscillation frequency points; responding to the broadband oscillation mode of the wind power grid-connected system, and returning to the step of obtaining the current broadband impedance characteristic of the wind power grid-connected system at the preset grid-connected point; wherein an online optimization algorithm is adopted to adjust control parameters in the process of executing the self-adaptive double-loop vibration suppression control in real time. According to the scheme of the invention, by forming a diagnosis-suppression-optimization intelligent closed loop, the stability of the wind power system can be actively and prospectively evaluated.

The present application relates to the technical field of oscillation disturbance source hierarchical positioning, and particularly relates to a wide-frequency oscillation disturbance source hierarchical positioning method based on compressed sensing and ISTA, which comprises collecting power of a power grid generator of a system, and storing the power of the generator as a time series; extracting a typical oscillation characteristic sub-sequence based on the time series to detect a state of the system, and obtaining a criterion result; sub-sampling the time series based on a compressed sensing technology to obtain a compressed signal; inputting the compressed signal and the criterion result into a disturbance area positioning network to output a disturbance area unit number; inputting the disturbance area unit number into an ISTA restoration network for restoration to obtain an oscillation restoration signal; inputting the oscillation restoration signal into a disturbance source positioning network for positioning to obtain a wide-frequency oscillation disturbance source unit number, which realizes accurate positioning of the oscillation disturbance source and solves the problem of low accuracy of existing wide-frequency oscillation disturbance source positioning methods in positioning tasks.

The application provides a method and system for detecting sub-harmonic oscillation based on a tunable wave trap, and a medium. A direct current digital filter and a tunable digital wave trap are cascaded to obtain a single-frequency oscillation signal detector. A wave trap angle frequency of the tunable wave trap is used as an independent variable, and an energy function is constructed based on a to-be-detected oscillation signal and an output of the single-frequency oscillation signal detector. A gradient descent method is used to iteratively update the independent variable in a negative gradient direction of the energy function with a fixed step length, to search for a minimum value of the energy function. When a gradient of the energy function with respect to the independent variable is zero, the corresponding angle frequency is determined as an angle frequency of the to-be-detected oscillation signal. The implementation process is simple and easy to implement, the calculation amount is small, and the real-time and accurate detection of the sub-harmonic oscillation signal can be realized.

The invention provides a low-frequency oscillation suppression method, system and device for a generator set, and relates to the technical field of generators, and the method comprises the steps: carrying out the real-time monitoring of the generator set, and obtaining a set monitoring sequence; performing low-frequency oscillation detection on the generator set to obtain a set oscillation thermodynamic diagram; adjusting the unit control decision according to the unit oscillation thermodynamic diagram; and performing multiple variation optimization on the unit control and adjustment group according to the unit adjustment fitness evaluation condition to obtain a unit adjustment optimization result, and performing low-frequency oscillation suppression management on the generator set according to the unit adjustment optimization result. According to the method and the device, the technical problems of insufficient power system stability, power supply quality and equipment safety caused by difficulty in balancing oscillation suppression, power supply tracking and equipment fault risks in the prior art can be solved, and optimal low-frequency oscillation suppression management considering the oscillation suppression effect, the power supply adaptability and the unit operation safety is realized; and stable operation of the target generator set is guaranteed for a long time.

The invention discloses an intelligent piezoelectric beam vibration suppression control method based on a fuzzy improved active disturbance rejection controller. Firstly, a kinetic model and a state-space equation of the intelligent piezoelectric beam are established; thirdly, according to the state-space equation of the intelligent piezoelectric beam, constructing a fuzzy improved active-disturbance-rejection controller, including designing a nonlinear Arcfu function based on an arctan function, and constructing an extended state observer and a nonlinear state error feedback control law based on the nonlinear Arcfu function; the fuzzy controller generates a deviation increment of the vibration displacement tracking error and the vibration speed tracking error according to the deviation of the vibration displacement tracking error and the vibration speed tracking error, and dynamically adjusts a control law parameter by using the deviation increment; finally, the vibration displacement of the intelligent piezoelectric beam is obtained in real time, the fuzzy improved active disturbance rejection controller generates system control quantity according to the vibration displacement, the system control quantity acts on the piezoelectric ceramic piece, and active vibration suppression control is conducted on the intelligent piezoelectric beam. According to the method, high-frequency oscillation is avoided, and the vibration suppression control effect is enhanced.

The application relates to the field of power system stability monitoring, and discloses a power system wide-frequency oscillation classification method and system. The method comprises the following steps: acquiring an oscillation signal and generating a time-frequency diagram; inputting the time-frequency diagram into a physical guided attention classification model, the model separates the features into double flows according to the time and frequency physical axes, respectively enhances the attention, fuses the features through a bidirectional cross-attention mechanism, and classifies. The system deploys the method by adopting an edge-host station collaborative architecture. Through deeply embedding the signal physical structure into the network design, the application solves the problem that the feature extraction is disconnected with the physical nature, and significantly improves the accuracy, robustness and generalization ability of the classification under strong noise and complex working conditions.

The application discloses a new energy station wide frequency oscillation online early warning method based on a virtual shunt ratio, and belongs to the technical field of power system stability analysis and control. The method comprises the following steps: injecting a harmonic small disturbance signal into a current or voltage sampling value of a new energy converter, synchronously recording a static var generator (SVG) branch current waveform and extracting a disturbance component, and calculating a virtual shunt ratio; obtaining wide frequency band data through frequency sweeping and obtaining a domain expression of the virtual shunt ratio by using vector fitting; solving the zero point of the expression to obtain station characteristic roots, and judging and warning an oscillation risk according to the position of the characteristic roots on a complex plane. The application does not need to obtain control parameters and line parameters of the new energy converter in the station, and does not need a high-power disturbance source, thereby solving the problems of high parameter dependency, difficult modeling and large calculation amount of the existing method, and realizing rapid online early warning of the wide frequency oscillation risk in the full "black box" state of the new energy station.

The application is suitable for the field of power system monitoring, and provides a power system wide-frequency oscillation damping monitoring method, device, equipment and computer readable storage medium. The method comprises the following steps: obtaining a time-domain estimation expression of a real part of an eigenvalue of a measured power generation unit under a selected dominant oscillation mode; collecting a speed-like variable signal and a power-like variable signal of the measured power generation unit in a preset time period; obtaining an angular frequency from an amplitude-frequency characteristic image obtained by Fourier transform on the speed-like variable signal; and substituting the angular frequency, the speed-like variable signal and the power-like variable signal into the time-domain estimation expression for calculation, and obtaining a final estimation value of the real part of the eigenvalue of the dominant oscillation mode of interest through iterative adjustment. The application can realize damping of power system wide-frequency oscillation in power generation unit monitoring, only needs to construct a time-domain estimation expression of a real part of an eigenvalue and process signal data, and does not need to perform high-dimensional modeling on the whole system, so that the accuracy is high and the feasibility is strong.

The application discloses a high-durability anti-aging structure of a high-frequency oscillation field source device, which is characterized by field source damping buffering, cavity low-stress coating and dynamic field state stable amplitude triple design, disperses high-frequency oscillation stress, softens field wave reflection impact, avoids peak high-intensity oscillation, comprehensively reduces piezoelectric material fatigue and cavity aging, and prolongs the service life of the whole machine. The structure does not affect the field operation performance, is simple to install, has low mass production cost, solves the problems of poor durability and easy aging of the high-frequency field source device, and is suitable for long-term continuous stable work of equipment.

The present application belongs to the technical field of signal processing, and particularly relates to a brain electrical high-frequency oscillation energy mutation detection method based on single-variable instantaneous energy entropy, aiming to improve the detection accuracy of epilepsy diagnosis. The method comprises the following steps: preprocessing electroencephalogram (EEG) data, dividing the preprocessed EEG data into sliding window segments based on the preprocessed EEG data, calculating wavelet coefficients of each sliding window segment to extract time-varying energy and Hjorth complexity. The wavelet coefficient refers to a coefficient obtained by wavelet transform to represent the time-frequency characteristics of a signal; the time-varying energy refers to a signal energy characteristic varying with time, and the Hjorth complexity is used to describe the waveform complexity of a signal. The time-varying energy and the Hjorth complexity are fused to obtain a fusion feature. The single-variable instantaneous energy entropy is calculated according to the fusion feature, and the epilepsy onset area is detected according to the mutation of the single-variable instantaneous energy entropy. The single-variable instantaneous energy entropy refers to an instantaneous entropy value calculated based on the energy distribution of a single-variable signal, and is used to represent the energy mutation of a signal.

The invention discloses a multi-frequency oscillation detection method, device, equipment and medium for a power system, and relates to the technical field of frequency oscillation detection, and the method comprises the steps: obtaining an oscillation signal of an oscillation component through a power grid signal of the power system; processing the oscillation signal of the oscillation component by adopting a sliding window discrete Fourier transform algorithm and an abc / dq coordinate transformation matrix to obtain an oscillation characteristic parameter of the oscillation signal; and acquiring a multi-frequency oscillation detection result of the power system according to the oscillation characteristic parameter of the oscillation signal. According to the method, the oscillation signal containing multiple frequencies can be detected, the approximate frequency of the oscillation signal is firstly determined through the low-resolution SDFT algorithm, then specific directional detection is carried out through channels, and compared with an existing discrete Fourier transform algorithm, a fast Fourier transform algorithm, a Prony algorithm, wavelet transform and other full-band detection methods, calculation resources can be effectively saved, and the detection efficiency is improved. The system load is reduced.

This invention relates to the field of electrical parameter measurement and analysis technology, and particularly to a method, system, and medium for measuring the initial phase of amplitude-frequency oscillations in AC power systems. The method includes: acquiring three-phase voltage sampling signals; constructing a mathematical model of the oscillation signal based on the sampling signals; performing coordinate transformation on the sampling signals to obtain direct-axis and quadrature-axis components; constructing an amplitude oscillation signal based on the direct-axis and quadrature-axis components and separating the amplitude modulation component; performing analytical expansion of the frequency modulation term based on the mathematical model of the oscillation signal to obtain an analytical expression for the frequency oscillation; performing frequency domain transformation on the time-domain signals corresponding to the amplitude oscillation signal and the analytical expression for the frequency oscillation, respectively; determining the initial phase of the amplitude modulation based on the phase information of the disturbance frequency component; and calculating the initial phase of the frequency modulation based on the phase relationship between the subsynchronous or supersynchronous component and the power frequency component. This invention effectively solves the problem of accurately measuring the initial phase of oscillations when amplitude-frequency oscillations occur at the grid connection point.

The application discloses a high-frequency oscillation suppression method and device of an MMC-HVDC system, and belongs to the technical field of flexible direct current power transmission system stability control; in view of the problem that the non-minimum phase characteristic of the MMC is caused by the control link delay, and further causes high-frequency oscillation of 1000-2500 Hz, a high-frequency impedance model of the system containing the delay is constructed, and the oscillation mechanism dominated by the non-minimum phase characteristic is determined; a third-order high-pass filter is connected in parallel with the PCC point of the MMC and the alternating current power grid, filter parameters are optimized, -90° phase compensation is realized in a negative damping interval, and the fundamental active power loss is reduced; the impedance characteristic is researched through an impedance detection method, high-frequency oscillation risk is judged, and remodeling effect is verified to suppress the oscillation; the application fundamentally eliminates the negative damping characteristic of the system, the suppression effect is better than that of a traditional passive filter, the influence on the steady-state and transient-state characteristics of the system is small, the application is suitable for different power grid working conditions, and the engineering practicability is high.

The invention discloses a shock wave simulation method for a shield segment explosion-proof test. Precise control over peak pressure fluctuation and pulse width errors is achieved by combining a high-precision mass flowmeter and electromagnetic parameter regulation and control on the basis of a quantitative relation model constructed based on the fluid dynamics theory, meanwhile, an electromagnetic pre-compression and chemical detonation composite driving mode is adopted, shock waves with the rise time shortened and the peak pressure reaching 300 MPa or above are generated, and the shock waves can be applied to the field of hydraulic engineering. The steep front edge and high-frequency oscillation of real explosion are reproduced, the waveform limitation of single air pressure driving is broken through, a multi-field coupling monitoring system achieves full-time-history data capture of duct piece strain, displacement, temperature and the like through a high-frequency sensor and a high-speed camera system, weak parts are accurately recognized, meanwhile, the 1500-DEG C high-temperature simulation capacity is achieved, and the system is suitable for being used in the field of high-temperature simulation. The critical failure pressure is accurately determined in combination with a stepped pressure test, various extreme working condition requirements are met, nanosecond synchronization and safety redundancy design is achieved through an intelligent control system, the experiment efficiency is improved, and a high-fidelity and repeatable test platform is provided for research on the anti-knock performance of the shield segment.

The application discloses an additional damping control method, device and system for inhibiting active low-frequency oscillation, wherein a phase modifier power (or rotating speed) signal and a bus voltage frequency signal are introduced respectively, a signal change amount is subjected to low-pass filtering, gain amplification and multi-stage lead-lag correction, and then a damping control output signal is obtained, the signal is superimposed on a given and feedback deviation input point of a voltage closed-loop control of a phase modifier excitation system, and additional damping effect is generated by the phase modifier excitation system. The application provides an additional damping control for phase modifier excitation, the additional control can exert the influence capacity of the phase modifier on the dynamic stability of active power low-frequency oscillation, so that the existing and gradually put-into-operation phase modifiers with different capacities in the system can be used to participate in inhibiting system low-frequency oscillation.