The paper presents methods for instantaneous harmonic analysis with application to high-quality pitch, timbre, and time-scale modifications. The analysis technique is based on narrow-band filtering using special analysis filters with frequency-modulated impulse response. The main advantages of the technique are high accuracy of harmonic parameters estimation and adequate harmonic/noise separati...

The paper analyzes the effects of harmonics in wind turbines by presenting a useful technique to reduce the effects of harmonics. In this paper by using a harmonic model of wind turbine, and using a harmonic reduction technique, the power quality of network will be improved and the number of harmonics decrease. The technique is combination of wavelet analysis and active filters. The results sho...

This paper describes two harmonic detection methods used in industrial shunt Active Filters. The methods are overall harmonic compensation and selective harmonic compensation. Both methods are described and analyzed in the paper together with several practical design steps for Adjustable Speed Drives applications. The methods are compared in the case of voltage unbalance and pre-distortion, com...

Active filters have become a viable alternative for controlling harmonic levels in industrial and commercial facilities. However, there are many different filter configurations that can be employed and there is no standard method for rating the active filters. This paper describes the active filter operation characteristics and develops standard ratings that can be used for filtering different ...

In this paper, the issue of single channel speech enhancement of non-stationary voiced speech is addressed. The non-stationarity of speech is well known, but state of the art speech enhancement methods assume stationarity within frames of 20–30 ms. We derive optimal distortionless filters that take the non-stationarity nature of voiced speech into account via linear constraints. This is facilit...

The advent of power electronics and computerized equipment in recent decades has brought enhanced efficiency and improved system but at the same time also created harmonics and waveform distortion to the power system network. With high harmonic contents present in the supply network, a higher equipment component failure rate or undesirable tripping of sensitive device might be experienced. This...

It has been established that shunt active power filters are suitable for compensating harmonics in the current fed type harmonic producing loads, likewise the series active power filter (APF) are considered to be suitable for voltage fed type harmonics-producing load. This paper discusses the indirect current control approach in terms of its simplicity and effectiveness for the operation of a s...

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...

A new frequency domain method for determining the fundamental frequency of speech is presented in this paper. This method uses the information contained in the short—term phase spectrum whereas the previous methods were limited to the amplitude spectrum. The short—term spectrum is computed by DFT and it is interpreted as the output of a bank of band—pass overlapping filters. Harmonic components...

This paper describes the implementation of Distributed Active Filters (DAFs). To share the workload of harmonic filtering, several Active Filter Units (AFUs) are placed on different locations which can perform the harmonic filtering without a direct communication. Different configurations of DAFs are described and are implemented using MATLAB /Simpower system Toolbox environment to observe thei...