‎Let $p(z)=z^s h(z)$ where $h(z)$ is a polynomial‎ ‎of degree at most $n-s$ having all its zeros in $|z|geq k$ or in $|z|leq k$‎. ‎In this paper we obtain some new results about the dependence of $|p(Rz)|$ on $|p(rz)| $ for $r^2leq rRleq k^2$‎, ‎$k^2 leq rRleq R^2$ and for $Rleq r leq k$‎. ‎Our results refine and generalize certain well-known polynomial inequalities‎.

A technique has been developed to actively identify the open-loop characteristics of a DC-DC converter while the unit operates. A digital controller is used to perform both the closed-loop control of the converter and to periodically identify the “plant” using a pseudo-random digital signal. Experimental results are provided for a digitally controlled 90W forward converter to demonstrate accura...

A6s t~ac t A flyback dc-dc converter is obtained from t h e conventional buck-boost converter by replacing t h e inductor with an isolation transformer. A transformer in the flyback converter is used to achieve a d c isolation between t h e input and the o u t p u t of t h e converter. This paper presents dc and small-signal circuit models for t h e flyback converter for continuous conduction m...

In this study investigation is done on an H-bridge switched inductor base cascade multilevel DC-DC boost converter. The proposed multilevel DC-DC boost converter topology improves the conversion efficiency of traditional topology. The proposed boost converter topology is differing from the traditional topology by the addition of switched inductor circuit. The switched inductor improved the conv...

In this paper, H∞ loop-shaping control is applied to improve the performance of a buckboost dc-dc power converter based on pulse-width-modulation (PWM) techniques. Here, classical control techniques (i.e., proportional-integral-derivative (PID) control) and post-modern control techniques (i.e., H∞ control), are used to design the feedback loop of a buck-boost dc-dc power converter. The results ...

This paper deals with the control scheme of the hybrid grid which lags in some important areas like smooth and fast power transfer in the grid and stable system operation under various conditions. For reliable operation of hybrid grid, the converter plays a crucial role which necessities an efficient control strategy at converter. Z inverse technique has been proposed at the converter in this p...

Single phase voltage converter structure with isolation transformer for applications in traction vehicles is presented. This paper shows simulation model of this type of converter and transformer model with modern magnetic material in OrCAD-PSpice simulation program. Two PWM control techniques are compared in order to eliminate voltage and current oscillations in primary winding of the transfor...

Was concentrated on tree phase matrix converter topology. Single-phase Matrix converter or SPMC was first implemented by Zuckerbeger4. Now presented a.Abstract. This paper presents the single phase matrix converter topology that will operate as an uninterruptible power supply circuit. A single circuit is developed.Single phase matrix converter SPMC performs a function such as frequency changer,...