Abstract – The components of harmonics are integral multiple of the fundamental component and the components of inter-harmonics are are non integral multiple of the fundamental component. AC-DC-AC conversion systems used in variable speed drive are sources of inter-harmonics. There are several reasons for inter-harmonic generation in variable speed drives. In this paper, the generation of inter...

A rapid algorithm to superimpose macromolecular models in Fourier space is proposed and implemented (SUPALM). The method uses a normalized integrated cross-term of the scattering amplitudes as a proximity measure between two three-dimensional objects. The reciprocal-space algorithm allows for direct matching of heterogeneous objects including high- and low-resolution models represented by atomi...

In this paper a novel hybrid algorithm for harmonics estimation in power systems is proposed. The estimation of the harmonic components is a nonlinear problem due to the nonlinearity of phase of sinusoids in distorted waveforms. Most researchers implemented nonlinear methods to extract the harmonic parameters. However, nonlinear methods for amplitude estimation increase time of convergence. Hen...

Due to sensitive and important applications of free-electron laser in industry and medicine, improvement of the power and efficiency of laser has always been emphasized. Therefore, understanding the created field and examining the properties of the field in waveguides with different shapes and studying the sustainability of electrons movement are particularly important. In this study, the beh...

Face recognition under varying pose is a challenging problem, especially when illumination variations are also present. Under Lambertian model, spherical harmonics representation has proved to be effective in modelling illumination variations for a given pose. In this paper, we extend the spherical harmonics representation to encode pose information. More specifically, we show that 2D harmonic ...

Time-stepping finite element method (FEM) has become a powerful tool in solving transient electromagnetic fields. The formulation can include complex issues such as time harmonics and space harmonics, nonlinear magnetic property of iron materials, external circuit and mechanical motion in the system equations. However, as the derivatives of physical quantities are usually unknown at the initial...

Spherical microphone arrays have been used for source localization in three-dimensional space recently. In this paper, a two-stage algorithm is developed to localize mixed far-field and near-field acoustic sources in free-field environment. In the first stage, an array signal model is constructed in the spherical harmonics domain. The recurrent relation of spherical harmonics is independent of ...

Abstract: A method is proposed for reducing speed ripple of permanent magnet synchronous motors (PMSMs) controlled by space vector pulse width modulation (SVPWM). A flux graph and mathematics are used to analyze the speed ripple characteristics of the PMSM. Analysis indicates that the 6P (P refers to pole pairs of the PMSM) time harmonic of rotor mechanical speed is the main harmonic component ...

[1] It is shown that intense ion cyclotron turbulence can be induced in the near-Earth space by shaped release of neutral gas of materials such as lithium, cesium, etc. Release of 1 ton of neutral lithium gas in the Earth’s equatorial plane at L = 2 can introduce about 30 GJ of energy which can be used to excite waves around the lithium ion cyclotron harmonics that readily evolves into the turb...

A recursion procedure for the analytical generation of hyperspherical harmonics for tetraatomic systems, in terms of row-orthonormal hyperspherical coordinates, is presented. Using this approach and an algebraic Mathematica program, these harmonics were obtained for values of the hyperangular momentum quantum number up to 30 ~about 43.8 million of them!. Their properties are presented and discu...