This paper analyzes the way to increase the energy efficiency of three phase converters applied to control AC motor drives, through the reduction of the total harmonic distortion (THD) of the output voltage and the reduction in the switching losses in the PWM inverter. The aim is to develop a system which selects the most adequate modulation technique required to simultaneously optimize the har...

This paper presents the comparative study of three phase twenty five level diode clamped and cascaded H-bridge multilevel inverters. The comparison is made in respect of requirement of devices, quality of output voltage and reduction of total harmonic distortion at the multilevel inverter terminals. In this work multicarrier sinusoidal pulse modulation control methods of Phase disposition (PD-P...

Increasing use of variable speed drives in industry causes harmonic proliferation in industrial power distribution supply system. Harmonic currents generated by the variable speed drives interact with power system impedance to give rise to harmonic voltage distortion. Thus it is essential to analyze, evaluate and introduce appropriate mitigation techniques for harmonic reduction in the power sy...

The Dynamic Voltage Restorer (DVR) is a commercially available, popular device to eliminate voltage sags and swells in the distribution lines. Its basic function is to inject the voltage difference (difference between the pre-sag and sag voltage) to the power line and maintains the pre-sag voltage condition in the load side. The efficiency of the DVR depends on the performance of the efficiency...

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...

Traveling Wave Tubes (TWTs) consist of different elements. The most important element of TWT is the RF circuit. RF circuits in helix TWTs need a dielectric support to hold the helix; this support also has an effect in electromagnetic properties of RF circuits. A novel dielectric support is proposed to reduce the second harmonic of helix TWTs. The dielectric support in this structure consists of...

DC underground traction systems are a powerful source of harmonic distortion, and so, suitable corrective actions have to be taken. For the design of these corrective actions simulation has proved to be a very useful tool. In this paper, the simulation of an active filter for the reduction of the current harmonic distortion of an underground traction system is presented.

This article aims to examine methods of optimizing GMM-based voice conversion systems performance in which GMM method is introduced as the basic method for improvement of voice conversion systems performance. In the current methods, due to using a single conversion function to convert all speech units and subsequent spectral smoothing arising from statistical averaging, we will observe quality ...

support and help. His precious advice and numerous discussions enhanced my knowledge and scientific inspiration. preparation of the laboratory setup is especially appreciated. Finally, I am very grateful for my wife Ann's and son Kacper's love, patience and faith. I would also like to thank my whole family, particularly my parents for their care over the years. Introduction 2 1. INTRODUCTION Me...