This paper presents a new method for robust fundamental frequency (F0) estimation in the presence of background noise and spectral distortion. We define degree of dominance and a dominance spectrum based on instantaneous frequencies. The degree of dominance allows us to evaluate the magnitude of individual harmonic components of speech signals relative to background noise while eliminating the ...

This paper presents an improved method for determining the contribution of harmonic distortion generated by utility and customer at the Point of Common Coupling (PCC) in a distorted power system. For this purpose, first the magnitude and phase of voltage and current at the PCC in each frequency are estimated by adaptive Kalman filter. Then the parameters of Thevenin equivalent circuits of load ...

This paper explains a control strategy SHE-PWM and a closed loop control of the cascaded multilevel inverter based on the modulation index. The modulation index is taken as the feedback to the cascaded multilevel inverter, the proposed system reduces the total harmonic distortion by optimizing the angles of the inverter and the DC voltage sources applied to the cascaded inverter. The specific l...

In power distribution networks, nonlinear loads produce harmonic currents that can pass through other sensitive locations in the power system and eventually back to the source. Harmonic currents can produce a variety of effects that are harmful to a power system structure. Consequentially, the deployment of new cost and energy efficient passive, active and hybrid filtering techniques is importa...

The uncontrolled three-phase bridge rectifier has the least line current distortion among six-pulse rectifiers; however, its total harmonic distortion (THD) of 31.08% is unacceptable as per the contemporary power quality standards. This paper seeks to address the issue by elimination of triplen harmonics in the line currents by providing a deltawye transformer at the ac interface i.e. between t...

The effects of optical injection locking on the nonlinear distortions of directly modulated semiconductor distributed feedback (DFB) lasers are investigated experimentally. The second harmonic distortion (SHD) and third harmonic distortion (THD), as well as the third-order intermodulation distortion (IMD3), are measured as functions of modulation frequency for both the free-running and injectio...

Industrial Static Var Generator (SVG) is typically applied at or near the load center to mitigate voltage fluctuation, flicker, phase unbalance, non-sine distortion or other load-related disturbance. Special attention is paid to the influence of grid voltage quality on SVG current, the non-sine distortion and unbalance of grid voltage causes not only the AC current distortion and unbalance but ...

A model of nonlinearity of the contact between the vibrator baseplate and the ground is proposed to describe the distortion of vibroseis signals in the near-field. A thin layer between the baseplate and the soil exhibits a strong nonlinear response because of the difference in its rigidity between the compression and tension phases. The model allows for a quantitative description of the transmi...

The rapid increase of non-linear loads in the last three decades has caused electrical quantities such as voltages and currents in 3-phase distribution systems to become distorted waveforms. This paper reviews, explains and discusses some new concepts, definitions and new available theory in the unbalanced and distorted systems. The usefulness of the proposed practical definitions is investigat...

In the early days of quantum mechanics, Schrödinger noticed that oscillations of a wave packet in a one-dimensional harmonic potential well are periodic and, in contrast to those in anharmonic potential wells, do not experience distortion over time. This original idea did not find applications up to now since an exact one-dimensional harmonic resonator does not exist in nature and has not been ...