8 results about "Harmonic coefficient" patented technology

The invention relates to a power distribution network harmonic analysis method and system, and the method comprises the steps: constructing a digital twinborn model of a power distribution network region, and selecting transformers in the region as analysis objects one by one; for each analysis object, various working conditions are simulated by changing the transformation ratio of the analysis object in a digital twin model, and voltage and current waveforms are collected and subjected to Fourier decomposition to obtain harmonic phasors; thirdly, performing phase reduction on the phasor data, separating a real part from an imaginary part to construct a matrix, and solving a harmonic coefficient matrix by using a least square method to realize error minimization; separating linear and nonlinear parts of the harmonic current, and calculating a harmonic emission capability parameter and a harmonic current risk parameter for quantitative evaluation; according to the method, all transformers are traversed and analyzed, and systematic harmonic evaluation of the whole power distribution network area is finally realized.

This invention provides a physical data signal processing method, apparatus, computer equipment, and storage medium. The method is based on a bispectral operation-based signal reconstruction approach. It calculates the harmonic coefficients, phase angle, and number of harmonic terms of the original signal's harmonic expression, as well as the harmonic coefficients, phase angle, and number of harmonic terms of the harmonic coefficients of the original signal's harmonic expression. Then, it reconstructs the harmonic coefficients of the original signal's harmonic expression and the original signal. During the reconstruction of the harmonic coefficients of the original signal's harmonic expression, the sample spacing of the harmonic coefficients is amplified, effectively increasing the dominant frequency of the physical data signal. This invention is applied to seismic exploration, effectively increasing the dominant frequency of the seismic wavelet signal, thus creating favorable conditions for improving the resolution of seismic exploration.

This invention discloses a method, system, and storage medium for identifying the surface wind pressure aerodynamic derivative that quantifies the contribution of aerodynamic instability to geometric shapes. The method includes: simultaneously acquiring the surface wind pressure time history and vibration displacement time history of the structural cross-section; processing the displacement signal to obtain the vibration frequency, amplitude, and phase difference; processing the wind pressure signal to obtain the wind pressure coefficient amplitude and phase difference at each measuring point; based on the theory of self-excited aerodynamics, establishing an explicit analytical formula through harmonic coefficient matching, and calculating the surface wind pressure aerodynamic derivative at each measuring point; analyzing the aerodynamic derivative at each measuring point, evaluating the contribution of each surface region to the overall aerodynamic derivative, and identifying key aerodynamic regions that excite or suppress self-excited vibrations. This invention degrades traditional macroscopic aerodynamic derivatives to spatial micro-elements, establishing a spatial mapping analytical closed chain between local wind pressure and aerodynamic derivatives, realizing spatial visualization and quantitative traceability of aerodynamic stability contributions, and providing a direct basis for targeted optimization of wind resistance for complex cross-sectional structures.

The invention discloses a sound source localization method based on same-order relative circular harmonic coefficients. The method is used for solving the singular problem of an open type circular array in a Bessel zero frequency interval and a high-order low-frequency range. When a circular harmonic domain characteristic wave beam is processed, mode intensity compensation is usually adopted to eliminate dependence on array characteristics. However, the problem of singularity exists in the frequency with very small modal intensity amplitude. In combination with the same-order mode intensity consistency characteristic, a new positioning feature same-order relative circular harmonic coefficient is designed, dependence on microphone array characteristics is removed, and the influence of a singular problem on a positioning result is also solved. The positioning algorithm provided by the invention has relatively low calculation complexity, and can be efficiently deployed on a hardware platform with limited resources. On the basis of keeping low calculation complexity, the method still shows excellent positioning precision in a high-noise and high-reverberation environment.

The invention provides a Chinese lute string fundamental frequency determination method and system, and the method comprises the steps: carrying out the time-frequency conversion of an audio signal, extracting a spectrum peak value, carrying out the energy weighting of the peak value according to a preset harmonic attenuation function, setting a candidate fundamental frequency set, constructing a preliminary harmonic cluster based on an initial non-harmonic coefficient, selecting a cluster with the highest energy, and calculating a real-time non-harmonic coefficient; and reconstructing candidate harmonic clusters according to the coefficient, and evaluating each harmonic cluster from two aspects of harmonic energy continuity and time domain correlation: calculating the sum of harmonic energy and combining with missing penalty to obtain an energy continuity score, and obtaining a time correlation score through a time cross-correlation mean value of fundamental frequency and each harmonic component energy envelope; and a comprehensive score is obtained after weighted summation.

The present application relates to the technical field of transformer design, and discloses a capacity determination method, system, medium and equipment of a double anti-star type transformer, the method comprising: obtaining a load loss set of a reference transformer under fundamental working conditions of a to-be-designed transformer, and each harmonic current effective value of the reference transformer under harmonic working conditions of the to-be-designed transformer; determining a harmonic coefficient set of the reference transformer under the harmonic working conditions of the to-be-designed transformer according to the harmonic current effective value and the load loss set; determining a capacity increase coefficient for quantifying the influence of the harmonic working conditions on the capacity of the reference transformer according to the load loss set and the harmonic coefficient set; and determining the capacity of the to-be-designed transformer according to the capacity increase coefficient. The present application can accurately calculate the loss caused by harmonics based on actual harmonic working conditions on site, thereby reasonably determining the transformer capacity and ensuring the operation reliability of the transformer under harmonic working conditions.

Embodiments according to the present invention comprise a signal feature determiner, e.g. a calculator or estimator, wherein the signal feature determiner is configured to determine information on a feature of a soundfield, e.g. a direction of arrival information or a diffuseness information, based on higher order, e.g. order larger than one, spherical harmonic coefficients, also designated as SHC, of a sound pressure, e.g. p(k), and / or SHC of a particle velocity, and based on a spherical harmonic order dependent weight, e.g. a weight g of a determination matrix G, wherein p(k) may, for example, form the basis of p (k). Further embodiments of the present invention comprise a signal feature determiner configured to determine information on a feature of a soundfield based on higher order circular harmonic coefficients of a sound pressure and / or a particle velocity and based on a circular harmonic mode dependent weight. Further embodiments relate to an audio encoder, a method and a computer program.

The invention discloses a helicopter body vibration active control method under time-varying vibration load excitation, and aims to solve the problems of poor environment tracking performance, reduced control effect and the like of helicopter vibration active control under large-range time-varying rotor vibration load. And a fluctuation harmonic control algorithm for reconstructing a fluctuation harmonic primary function by identifying an excitation response harmonic coefficient is provided, so that the aim of efficiently controlling the vibration of the machine body under the condition of large-range time variation of the vibration load of the rotor wing is fulfilled. The method has an efficient vibration environment real-time tracking capability, and can realize the control effects of high efficiency, high adaptability and high vibration environment tracking performance when the vibration load is subjected to large-range time varying.