50 results about "Forced oscillation" patented technology

The invention relates to a low-frequency forced oscillation disturbance source positioning and pre-judging method for an electric power system. The method comprises the following steps: acquiring an active power daytime plan of a conventional unit and a predicted daytime power of a wind power plant, and updating data at preset time intervals; based on an active power daytime plan of a conventional unit and a predicted daytime power of a wind power plant, dynamic low-frequency forced oscillation detection is performed on the active power daytime plan of the conventional unit and the predicted daytime power of the wind power plant in a future preset time interval by using a sliding time window; obtaining active power data of conventional units and wind power plants in a possible oscillation time window to construct a numerical matrix; and inputting the numerical matrix into a trained CNN-SVM positioning model, and pre-judging occurrence time of potential conventional units and wind power plants possibly causing low-frequency forced oscillation and corresponding windows in a future preset time interval. Compared with the prior art, the method has the advantages of being capable of achieving accurate positioning results under the condition of small samples and the like.

The invention belongs to the technical field of wind tunnel tests, and discloses a dual-body track capturing wind tunnel test method considering an unsteady effect of a disturbing flow field. The invention discloses a dual-body capture trajectory wind tunnel test method considering an unsteady effect of a disturbing flow field. The method comprises the following steps: determining a dynamic derivative needing to be simulated; calculating a dynamic derivative under the disturbing flow field by adopting a numerical forced oscillation method; designing and manufacturing a test device; installing a test device; starting the separated body model jet flow simulation device; starting a wind tunnel, and performing a double-body track capturing wind tunnel test; and analyzing and processing dual-body capture track wind tunnel test data. According to the dual-body capture track wind tunnel test method considering the unsteady effect of the disturbing flow field, dynamic characteristic influence quantity taking a key dynamic derivative as a characterization parameter is coupled in a capture track test process with relatively high precision, so that dual-body dynamic aerodynamic characteristics and separation tracks which are closer to a real separation process are obtained; the test simulation accuracy is improved, and the engineering practical value is achieved.

The invention discloses an electric power system multi-source forced oscillation positioning method based on a graph attention network and variational mode decomposition. The method comprises the following steps: acquiring power grid topology data of a target electric power system and attribute data of each node; inputting the power grid topology data and the attribute data of each node into a pre-trained target network model, wherein the topology perception space decoupling network processes the power grid topology data and the attribute data of each node and outputs the energy contribution degree of each node; the frequency domain time decoupling network processes the attribute data of each node and the corresponding energy contribution degree and outputs a synchronous machine component and a fan component; and the physical constraint oscillation classification network processes the synchronous machine component and the fan component and outputs a multi-source forced oscillation positioning result. According to the invention, the modeling of the electrical connection relation between the power grid nodes is realized through the topology perception space decoupling network, and the decoupling of the synchronous machine and the fan component is realized through the frequency domain time decoupling network, so that the precision of oscillation source space positioning is improved.

The invention belongs to the technical field of fan torsional vibration prediction, and particularly relates to a torsional vibration prediction method, device and equipment for a net-forming type direct-driven fan and a storage medium, and the method comprises the steps: constructing a small signal model of the net-forming type direct-driven fan; based on a shafting dual-mass-block model, deducing the relation between the direct-drive fan port voltage and current signals and the direct-drive fan shafting torsional vibration when forced oscillation occurs; when forced oscillation occurs, a transfer function between different power grid node ports is obtained by constructing a wind power plant s domain node admittance model, so that required voltage and current signals of the power grid node ports are calculated, and the calculated voltage and current signals are used as input of a small signal model of a grid-constructing type direct-driven fan. And calculating the torsional vibration of the shaft system of the mesh-forming type direct-drive fan caused by forced oscillation by combining the relationship between the voltage and current signals of the port of the mesh-forming type direct-drive fan and the torsional vibration of the shaft system of the mesh-forming type direct-drive fan. The potential torsional vibration problem can be found and processed in time, and faults are avoided.

The invention discloses a forced power oscillation disturbance source positioning method based on KDE transfer entropy causal analysis, and belongs to the technical field of power system operation and maintenance. The forced power disturbance source positioning is realized by analyzing the causal relationship between disturbance source and non-disturbance source unit measurement signals in the forced power oscillation process of the system. According to the method, the causal analysis method is used for solving the forced power oscillation disturbance source positioning problem, dependence on a system model and parameters is eliminated, rapid online positioning of the forced oscillation disturbance source can be achieved only according to measurement data, and the positioning precision and positioning efficiency of the forced oscillation disturbance source are effectively improved.

An electronic oscillator circuit includes: a resonant circuit including an inductor and a capacitor, where each of the inductor and the capacitor has a first terminal connected to a first side of the resonant circuit and a second terminal connected to a second side of the resonant circuit; a first current controller; and a second current controller; wherein the first current controller is connected to a first side of the resonant circuit; wherein the second current controller is connected to a second side of the resonant circuit; wherein the first current controller is arranged to enable it to act as a current source of the resonant circuit; wherein the second current controller is arranged to enable it to act as a current tank of the resonant circuit; wherein the first current controller and the second current controller are configured such that the injection current flows from the first current controller to the second current controller through the resonant circuit when the first current controller and the second current controller are in a first state; and when the first current controller and the second current controller are in the second state, no current is injected into the resonant circuit. The current injected in this manner allows energy to be injected into the resonant circuit, which forces oscillation in the resonant circuit to proceed at a predetermined frequency different from the natural resonant frequency of the resonant circuit.

The invention relates to the field of power systems, in particular to a method and system for improving the low-frequency oscillation suppression capability of a power system stabilizer, and the method comprises the steps: building an excitation regulator hardware-in-loop simulation platform to form a closed-loop test environment; constructing a model containing prime mover forced oscillation and generator special operation conditions; configuring simulation parameters based on the actual constant value of the unit; injecting multi-modal disturbance and acquiring a dynamic signal; calculating a multi-dimensional index for evaluating the low-frequency oscillation suppression capability of the PSS; generating a full-working-condition adaptability judgment result through a dynamic weight distribution algorithm; and if not, optimizing the PSS parameters by taking the weighted comprehensive score as a target, and repeating the test until the requirements are met. According to the invention, the problem that the low-frequency oscillation suppression capability of the traditional PSS parameter setting is insufficient under a special working condition is solved.

The invention discloses a power system forced oscillation source positioning method based on ICEEMDAN-ITEO, and belongs to the technical field of power system stability analysis and control. In a signal adaptive decomposition and modal extraction part, an ICEEMDAN algorithm is utilized to decompose a wide-area measurement signal, suppress modal aliasing and noise interference and obtain a modal component with physical significance; the energy weight of each modal component is calculated by adopting ITEO, the identification capability of the dominant forced oscillation component is enhanced through an adjustable resolution parameter, and the time domain waveform of the dominant forced oscillation component is reconstructed; in the oscillation source judgment part based on the dissipation mode energy flow, the dissipation mode energy flow of each generator port is calculated according to the dominant oscillation mode component, and accurate judgment of a disturbance source is realized through linear fitting of slope characteristics of the dissipation mode energy flow; in the verification and application part of the oscillation source positioning result, the accuracy and robustness of the method in different noise and disturbance scenes are verified through a test system comprising a network-forming fan.

The invention discloses a hybrid CGAN-based power system forced oscillation source positioning method, and the method comprises the steps: inputting to-be-recognized data into a trained CNN classifier, and obtaining an oscillation source recognition result; wherein the CNN classifier is trained according to the mixed data set; the mixed data set is constructed according to FO generation data generated by the trained mixed CGAN and real data; the FO generation data is false forced oscillation data; each group of real data comprises active power, reactive power, voltage amplitude and voltage phase angle; the hybrid CGAN is obtained according to the CNN, the BiLSTM and the attention mechanism. According to the method, the convolutional neural network, the bidirectional long-short-term memory network and the attention mechanism are fused into the generator and the discriminator of the CGAN, so that the similarity between the FO generation data and the real data is improved, the FO generation data and the real data are used for training, and the precision of forced oscillation source positioning can be effectively improved.

The invention discloses a power grid synchronous broadband forced oscillation detection and positioning method and system and a medium, and the method comprises the steps: obtaining an oscillation data sequence of a power grid and a power system topological graph, and inputting the oscillation data sequence and the power system topological graph into a pre-trained multi-task graph sequence network, so as to obtain an oscillation source positioning detection result; comprising the following steps: performing information transmission on an oscillation data sequence through a convolutional layer, a pooling layer and an output feature obtained by a created embeddable sequence autoregression module and a topological graph of a power system through a constructed multi-task graph sequence network, and obtaining node features of each node through a gate control cycle unit GRU, and inputting a graph-level detection branch and a node-level detection branch to realize event type classification of the oscillation source and positioning of the oscillation source. The method aims at reducing interference of other information on broadband oscillation information, data are dynamically analyzed from the two dimensions of time and space, and broadband oscillation source positioning is rapidly and accurately achieved.

The application discloses a kind of power system stabilizer implementation methods for enhancing power forced oscillation damping effect, by the change of rotating speed and active change quantity are respectively after low-pass filtering and low resistance filtering synthesis obtains rotating speed-power synthesis signal, again after leading-lag correction link, as PSS output.The application generates effective positive damping by the change of rotating speed after filtering when active power forced oscillation occurs in speed regulation system, avoids that the negative damping effect of existing PSS-2B model can intensify active power fluctuation;When machine-network damping oscillation, produce additional positive damping effect similar to in PSS-2B model, and have good anti-adjusting effect.

The utility model provides a deep sea netting forced oscillation experiment device, which belongs to the technical field of ocean engineering, and comprises two pairs of support rods I which are distributed up and down, two reinforcing ribs I are arranged between each pair of support rods I which are distributed up and down, and two reinforcing ribs II are arranged between each pair of support rods I which are distributed up and down. A square frame is installed in the first supporting rods, first three-component force instruments are installed at the corners of the square frame, and second three-component force instruments are installed on the two first supporting rods which are located at the rear end and transversely distributed respectively. The device solves the problems that high-amplitude oscillation and high-speed water flow are involved in the experiment period, so that the fishing net is damaged, and replacement and installation of the fishing net are troublesome.

The present invention discloses a method for locating a forced oscillation source based on a wavelet dissipation energy spectrum, which includes: performing wavelet transform on the electrical variation quantities of a generator to obtain a wavelet coefficient matrix of each electrical variation quantity; calculating the wavelet dissipation energy spectra of each generator at each wavelet coefficient matrix, and positioning the key scale wavelet coefficients strongly related to forced oscillation according to the variation trend of the wavelet dissipation energy spectra at each wavelet scale coefficient; extracting the wavelet dissipation energy spectra corresponding to each generator at the key scale wavelet coefficients; arranging the wavelet dissipation energy spectra of n generators in a columnar manner, and locating the oscillation source according to the proposed criterion for locating a forced oscillation source in a power system based on the wavelet dissipation energy spectrum; and outputting the result of locating the forced oscillation source. The present invention not only inherits the characteristic of the traditional DEF that it can locate the forced oscillation source without a detailed system model and component parameters, but also avoids the need for signal reconstruction processing of the required electrical quantities in the traditional time-domain DEF, thereby improving the efficiency of locating the forced oscillation source.

The invention discloses an oscillating source station single-station positioning and removing method based on meta-learning, electronic equipment and a storage medium, and relates to the technical field of power systems and automation thereof. Comprising the following steps: acquiring oscillation operation data of a single station, the oscillation operation data comprising electrical characteristics of a station exit; performing feature extraction on the oscillation operation data through a pre-trained neural network model, and judging whether the single station is an oscillation source or not; generating an optimal initial parameter of the neural network model based on a meta-learning process, wherein the meta-learning process is trained by using a forced oscillation sample; and if the single-field station is an oscillation source, triggering a circuit breaker to execute cutting operation, and suppressing oscillation propagation. Compared with a traditional oscillation source positioning method, the method avoids a data transmission process between stations, avoids communication difficulty, and has engineering practicability and timeliness.

The application discloses a parameter setting method, device and system for a swing reactance of an excitation regulator, wherein the parameter setting method adds forced oscillation to a speed regulator link in a closed-loop simulation test environment, so as to stimulate equal-amplitude oscillation of mechanical power and unit frequency in a set frequency range; the error between a real signal value output by a real excitation device and a simulation signal value output by a simulation test model is calculated, the initial value of the swing reactance parameter is selected according to the error, the adaptability and effectiveness of the swing reactance are verified based on the initial value, the test result is obtained through a voltage step test under a set working condition, and the swing reactance parameter is modified according to the test result, so that the active power fluctuation when the PSS is put into operation meets the set condition. The parameter setting method provided by the application can reduce the risk of power oscillation accidents caused by large unit speed calculation error due to unreasonable swing reactance parameter setting and weak damping or even negative damping of the PSS.

The utility model relates to the technical field of magnetic oscillation, and discloses a novel magnetic oscillator which comprises a base, a circuit board is installed in the base, the bottom of the circuit board is in threaded connection with a coil framework, a central column is sleeved with the circuit board, and front plates at the two ends of the magnetic base are sleeved with the surface of the central column. The surface of the central column is sleeved with a magnetic base middle-end iron plate, and the upper end and the lower end of the magnetic base middle-end iron plate are provided with circular magnets. Compared with a traditional oscillator which adopts a cam eccentricity principle and is driven by a motor, a magnetic force driving mode does not need a large motor and a large transmission mechanism, the overall structure is more compact, the occupied space is small, the first guide column and the second guide column are arranged and are fixed through the pin and the second bolt, and the operation is convenient. And the use of mechanical transmission parts is reduced, the problem of serious abrasion of a transmission mechanism and a supporting rod after long-time movement is avoided, the service life of the device is prolonged, and the stability of the device is improved.

The present application belongs to the technical field of fan torsional vibration prediction, and particularly relates to a grid-connected direct-drive fan torsional vibration prediction method, device, equipment and storage medium. The method comprises: constructing a small signal model of the grid-connected direct-drive fan; based on a shafting double-mass block model, deducing the relationship between the port voltage and current signals of the direct-drive fan and the torsional vibration of the shafting of the direct-drive fan when forced oscillation occurs; when forced oscillation occurs, by constructing a wind farm s-domain node admittance model, the transfer function between different grid node ports is obtained, so as to calculate the required grid node port voltage and current signals, taking the calculated voltage and current signals as the input of the small signal model of the grid-connected direct-drive fan, and combining the relationship between the port voltage and current signals of the grid-connected direct-drive fan and the torsional vibration of the shafting of the grid-connected direct-drive fan to calculate the torsional vibration of the shafting of the grid-connected direct-drive fan caused by forced oscillation. It is helpful to timely find and handle potential torsional vibration problems and avoid the occurrence of faults.

1. The name of this design product: forced oscillation respiratory impedance test device. 2. Purpose of this design product: used for lung function testing. 3. The design key point of this appearance design product lies in the shape. 4. The picture or photo that best illustrates the design points: three-dimensional picture.

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The invention relates to the technical field of power distribution networks, in particular to a forced oscillation detection and positioning method and system for a power distribution network. Comprising the following steps: performing cut set division on a power grid by adopting a spectrogram theory, and repeatedly performing cut set division based on a sub-grid energy transfer value; and analyzing a key line of the cut set line based on the betweenness centrality, the power fluctuation value and the frequency and phase angle data of the cut set. According to the method, binary segmentation is carried out through a Fiedler vector, a natural cut set structure in the power grid can be effectively identified, the power grid is divided into two sub-grids, nodes in each sub-grid have higher connectivity, key line candidates are determined through three dimensions of betweenness centrality, power fluctuation, frequency deviation and phase angle deviation respectively, and the power grid is divided into two sub-grids. The method is advantaged in that identification accuracy can be substantially improved, through combination of IMF decomposed by EMD and Hilbert transform, instantaneous frequency and amplitude can be extracted, and oscillation intensity and frequency on each key line can be monitored in real time.

The invention discloses a forced oscillation suppression method combining phase shift compensation and active damping, and belongs to the technical field of stable operation analysis of a power system. According to the forced oscillation suppression method combining phase shift compensation and active damping, most inter-harmonic disturbance sources are suppressed through direct-current voltage phase shift compensation, system damping is improved in a small-amplitude mode by combining active damping control, and the forced oscillation amplitude is suppressed under the condition that system performance is not affected. The mechanism that the inter-harmonic disturbance source triggers forced oscillation of the forced system is elaborated by using an equivalent disturbance equation, the influence of the amplitude of the inter-harmonic disturbance source and the damping of the forced system on the amplitude of forced oscillation is considered, and a forced oscillation suppression strategy of phase shift compensation and active damping is combined. The amplitude of an inter-harmonic disturbance source is suppressed through phase shift compensation, and the weak damping state of a forced system is improved through active damping, so that the amplitude of forced oscillation is suppressed.

The invention discloses an energy storage low-frequency oscillation suppression method based on a damping controller and a resonance controller, particularly relates to the field of low-frequency oscillation suppression, and comprises the following steps: judging the type of low-frequency oscillation, then adaptively selecting and online setting the corresponding damping or resonance controller, and generating compensation power. According to the energy storage low-frequency oscillation suppression method based on the damping controller and the resonance controller, a negative damping oscillation and forced oscillation dual-discrimination access is constructed, so that the type of low-frequency oscillation is effectively identified, and the defect that the effective identification capability of the oscillation type is lacked is overcome; the controller is adaptively selected according to the oscillation type, targeted suppression is applied to different types of oscillation, invalid adjustment of a single control strategy is avoided, resource waste of the energy storage system is reduced, suppression efficiency is improved, service life attenuation of the energy storage device is slowed down, and forced oscillation energy propagation is suppressed.

The invention discloses a CPSD-based power system forced oscillation source equipment level tracing method, and relates to the technical field of power system forced oscillation disturbance source equipment level positioning, and the method comprises the steps: collecting and calculating the active power, reactive power, frequency and voltage amplitude measurement data of a generator node during a forced oscillation period; obtaining a dynamic component of the relative steady-state value; calculating a frequency domain dissipation energy spectrum, and confirming a forced oscillation dominant oscillation frequency and a forced oscillation source; respectively calculating the frequency domain cross-power spectral density of the speed regulation system and the excitation system during the forced oscillation period; calculating amplitude spectrums and phase spectrums of each generator speed regulation system and excitation system at the forced oscillation frequency, and cooperatively positioning forced oscillation disturbance equipment by the amplitude spectrums and the phase spectrums; and calculating the energy contribution rate of each generator speed regulation system and excitation system, and determining the dominant forced oscillation disturbance equipment. Therefore, by adopting the method, the control system where the disturbance source is located can be accurately positioned, and forced oscillation equipment-level positioning is realized.

The invention discloses a power system low-frequency oscillation monitoring and analysis method, system, equipment and medium, and relates to the technical field of power system analysis, and the method comprises the steps: reading PMU data, and extracting oscillation features according to fluctuation changes; if an oscillation sign occurs, rapidly determining the oscillation frequency by using fast Fourier transform (FFT), and if the adjacent stations of the regional power grid detect oscillation at the same frequency, determining that the power grid oscillates; based on the oscillation characteristic data, weak damping oscillation monitoring analysis is carried out, and an online grouping result of a synchronous power grid unit and a node injection active power oscillation mode is output; and performing forced oscillation monitoring analysis, and outputting an oscillation source positioning result of the synchronous power grid based on transient energy integration. The method can quickly confirm the oscillation mode and the oscillation source when the power system oscillates, assists a dispatcher in quickly and accurately understanding the situation of the oscillation source of the power grid, takes effective measures to eliminate the influence of low-frequency oscillation on the operation of the power grid, and improves the safety and stability of the power system.

1. The name of this design product: forced oscillation respiratory impedance test device. 2. Purpose of this design product: used for lung function testing. 3. The design key point of this appearance design product lies in the shape. 4. The picture or photo that best illustrates the design points: three-dimensional picture.

The invention discloses a forced oscillation hydrodynamic experiment device for covering a buoyancy block rigid riser, which comprises an actuation module, a physical quantity sensing module, a rigid riser and a buoyancy block model, and is characterized in that the physical quantity sensing module is mounted on an actuation control module, the rigid riser is mounted on the physical quantity sensing module, the buoyancy block model is mounted on the rigid riser, and the buoyancy block model is mounted on the rigid riser. Therefore, the motion response of the rigid riser and the hydrodynamic load of the rigid riser can be measured in real time. The high-Reynolds-number forced oscillation experiment can be carried out on the rigid cylinder covered with the buoyancy block, the hydrodynamic coefficient of the rigid cylinder covered with the buoyancy block in a high-Reynolds-number flow field is obtained, and then a hydrodynamic coefficient library used for forecasting is established. The experimental device is simple in structure and easy to build and disassemble, meanwhile, the rigid stand pipe model is easy to disassemble, other stand pipe accessory structures can be replaced, and the experimental mode is flexible.

The invention discloses a progressive positioning method for a forced oscillation source of a power system considering a grid-forming type double-fed fan, and the method comprises the steps: carrying out the spectrum Granger causal analysis of the time series of the output active power of each synchronous machine which is strongly related to oscillation and the grid-forming type double-fed fan, and judging the causal relationship between power generation units; preliminarily positioning a power generation unit where the forced oscillation disturbance source is located; furthermore, an unknown input observer based on performance constraint is adopted to perform positioning verification, and the unknown input observer with the performance constraint is designed based on linear models of power generation units such as a synchronous machine with a potential forced oscillation source and a grid-forming double-fed fan. And establishing a structured residual set capable of effectively representing the forced oscillation disturbance source in the power generation unit by using the observer, and comparing each residual frequency spectrum in the residual set to realize accurate positioning of the forced oscillation disturbance source. Therefore, rapidity, convenience and accuracy required by positioning can be met.

The invention relates to a method for identifying shock wave motion frequency and growth rate, which comprises the following steps of: performing modal decomposition on airfoil profile surrounding flow field pressure data of transonic airfoil profile forced oscillation by using a single-frequency modal decomposition method to obtain frequency and modal characteristics of a surrounding flow field during transonic airfoil profile forced oscillation; the single-frequency modes are sequenced according to the energy ratio from large to small, the first-order mode is shock waves formed on the two sides of the airfoil profile under forced oscillation, and the frequency of the first-order mode is consistent with the motion frequency of the shock waves; the second-order mode reflects frequency doubling structures formed on the two sides of the airfoil profile in the swing process of shock waves on the two sides of the airfoil profile; the third-order mode reflects a slow evolution structure of the flow field from the initial state to the periodic pulsation state, and the frequency of the third-order mode is the frequency corresponding to the total physical duration of all the flow fields participating in mode decomposition; and identifying the shock wave growth rate according to the time coefficient amplitude of each order modal. The frequency and growth rate of the shock wave can be accurately captured, and the form of the shock wave is given.

This application relates to the field of marine engineering technology, and discloses a floating breakwater with a resonant cavity and its hydrodynamic performance analysis method. The method includes: constructing a floating breakwater model; determining the target length and target width of the resonant cavity, the wave-facing open-type wave-dissipating chamber, and the wave-repelling open-type wave-dissipating chamber on the leeward side; dividing the entire fluid domain of the floating breakwater into multiple regions; obtaining the velocity potential of each region; calculating the wave force of the floating breakwater; using the velocity potential of each region to express the added mass and radiation damping of the floating breakwater when it undergoes unit forced oscillation, so as to construct the motion response equation of the floating breakwater in the frequency domain under wave action; obtaining the transmission coefficient and energy dissipation coefficient of the floating breakwater through the equation set, and evaluating the shielding performance and wave-dissipating performance of the floating breakwater based on each coefficient. The synergy of the resonant cavity and the open-type wave-dissipating chamber can improve the wave-dissipating efficiency, and the analysis method can provide an efficient and reliable basis for the design of breakwaters.

Four-eccentric-wheel-driven forced oscillation device for ultra-precision lapping, comprising a frame, a four-wheel drive shaft system and an oscillation mechanism. The four-wheel drive shaft system includes an eccentric shaft, a right oscillation frame assembly, a left oscillation frame assembly, a right drive eccentric wheel pair and a left drive eccentric wheel pair, a front support bearing of the eccentric shaft and a rear support bearing of the eccentric shaft. The two eccentric wheels of the right drive eccentric wheel pair are respectively installed inside the front support bearing of the eccentric shaft and the rear support bearing of the eccentric shaft. The two eccentric wheels of the left drive eccentric wheel pair are respectively installed inside the right drive eccentric wheel pair. The two oscillation frames of the right oscillation frame assembly respectively enclose the two eccentric wheels of the right drive eccentric wheel pair therein. The two oscillation frames of the left oscillation frame assembly respectively enclose the two eccentric wheels of the left drive eccentric wheel pair therein. The present invention has excellent performances such as better oscillation linearity, stable oscillation frequency and amplitude, smoother oscillation and small driving torque, and can maintain good oscillation precision and performance for a long time.