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K. Sankara Rao

Bio: K. Sankara Rao is an academic researcher from Concordia University. The author has contributed to research in topics: Thyristor drive & Thyristor. The author has an hindex of 1, co-authored 2 publications receiving 6 citations.

Papers
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Journal ArticleDOI
TL;DR: A digital simulator for the analysis of any thyristor converter based upon a topological method of formulation of state equations and power thyristors and diodes are modelled as inductances is developed.
Abstract: This paper deals with a digital simulator for the analysis of any thyristor converter. The analysis is based upon a topological method of formulation of state equations and power thyristors and diodes are modelled as inductances. The value of each thyristor inductance changes from a finite value equal to the di/dt limiting series inductance, while conducting, to an infinite value when blocked. The simulator takes into consideration the presence of the snubber circuits associated with each thyristor element. The simulator library which has been named ATOSEC I has been developed having in mind the creation of a tool for the design by computer aided analysis of power electronic converters. It has been presently implemented on a CDC CYBER and will be available to prospective users from the authors.

6 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe a digital simulator for the analysis of any thyristor converter, based upon a topological method of formulation of state equations, and modelled power thyristors and diodes as inductances.
Abstract: Describes a digital simulator for the analysis of any thyristor converter. The analysis is based upon a topological method of formulation of state equations. Power thyristors and diodes are modelled as inductances. The value of each thyristor inductance changes from a finite value equal to the di/dt limiting series inductance, while conducting, to an infinite value when blocked. The simulator takes into consideration the presence of the snubber circuits associated with each thyristor element. The simulator library which has been named ATOSEC I has been developed with computer aided design power electronic converters in mind. It has been implemented on a CDC CYBER and will be available from the authors.

Cited by
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Proceedings ArticleDOI
24 Jun 1985
TL;DR: This paper describes a new and efficient computeraided package program for general power-electronic systems and describes how this program can be implemented in a simple and efficient manner.
Abstract: Described is a new and efficient computeraided package program for general power-electronic systems.

27 citations

Dissertation
02 Jul 2015
TL;DR: In this paper, the authors describe the evolution of mes travaux de recherche effectues au Cours de Nantaise for 20 dernieres annees, including the transmission of donnees sur un reseau module en largeur d'impulsion (MLI).
Abstract: Ce memoire retrace mes activites d’Enseignant-Chercheur depuis ma nomination a l’IUT de Nantes en 1993. Ce document temoigne de l’evolution de mes travaux de recherche effectues au cours de ces 20 dernieres annees au gre des rapprochements des differents laboratoires de la region Nantaise. La modelisation de la chaine de conversion de l’energie electrique est la ligne directrice de mon activite. Mes premiers travaux sont lies aux thematiques developpees au sein du GE44 puis de l’IREENA. Ils concernent tout d’abord la modelisation des convertisseurs de puissance et des dispositifs d’alimentation electrique pour l’optimisation de la regulation des convertisseurs et la maitrise de la pollution des reseaux. Un parametre essentiel dans le dimensionnement des convertisseurs de puissance est la temperature des semiconducteurs. Les competences acquises durant ces premieres annees ont ete mises a profit pour elaborer un simulateur electrothermique rendant compte de l’evolution de la temperature de jonction des semiconducteurs en fonction des differentes conditions de fonctionnement. Des modeles thermiques compacts ont ete developpes pour optimiser la simulation numerique des convertisseurs statiques. Depuis une dizaine d’annees, mes activites de recherche se sont recentrees autour d’une problematique liee au transport de donnees sur les reseaux d’energie. Ce domaine fut l’occasion de developper des activites pluridisciplinaires au sein du laboratoire. Cette activite se situe a la frontiere de l’electronique de puissance et des communications numeriques. Les premiers travaux correspondent a la transmission de donnees sur un reseau module en largeur d’impulsion (MLI) au sein d’une association convertisseur-machine a des fins de commande et de monitoring. Les seconds travaux abordent la gestion des batteries Li-ion dans une application d’eclairage autonome. Le point commun aux deux dernieres activites est la transmission de donnees par une technologie du type courant porteur en ligne (CPL). Depuis 2012, cette problematique est incluse dans l’equipe Systemes de Communications Numeriques (SCN) du laboratoire IETR.

16 citations

Journal ArticleDOI
TL;DR: A new general method, the method of adjusted voltage sources, is introduced in the digital computer simulation of electric circuits containing power semiconductors (diodes and thyristors), which can be extended easily for simulating, e.g., short-circuit phenomena.
Abstract: This paper deals with the digital computer simulation of electric circuits containing power semiconductors (diodes and thyristors). The semiconductors are supposed to operate with line commutation. After surveying briefly the traditional simulating methods, a new general method is introduced: ``the method of adjusted voltage sources.'' Using this method, the semiconductors are represented by voltage sources. In the case of a conducting semiconductor, the voltage of the voltage sources corresponding to the semiconductors is zero, but, in the opposite case, it is adjusted to cause zero current through the semiconductor. This means that the simulation is performed similarly as in the case of linear circuits, but in every point of the simulation, several auxiliary computations are to be carried out in order to obtain the voltage of the nonconducting semiconductors. The operation of the program using this method was verified by numerous examples, including the computation of switching transients and quasi-stationary state. It must be noted that the program cannot be used for finding the quasistationary state. However, the method can be extended easily for simulating, e.g., short-circuit phenomena. Examples show the efficiency of the new simulation method.

5 citations

Journal ArticleDOI
TL;DR: In this article, an auxiliary impulse commutated thyristor inverter is described that is capable of providing a wide range of output ac voltage and output frequency which is useful in variable speed ac drive applications.
Abstract: A new economical auxiliary impulse commutated thyristor inverter is described that is capable of providing a wide range of output ac voltage and output frequency which is useful in variable speed ac drive applications. Output voltage control is provided by a pulse frequency modulation technique, and input dc voltage to the inverter is constant and can be provided by a diode rectifier bridge. The parameters for the various circuit elements, such as commutating inductances and capacitances, di/dt limiting series thyristor inductances, and dv/dt limiting RC snubber circuits are all calculated from a dynamic simulation of a single-phase version of the inverter circuit using a software named ATOSEC I developed at the Universitedu Quebec for a CDC 6400/IBM-370 computer. Experimental results obtained on a practical single-phase inverter are compared with those predicted from computer simulation and performance characteristics obtained in the case of a practical three-phase pulse frequency modulated inverter providing variable output voltage and variable output frequency are reported.

4 citations

Journal ArticleDOI
TL;DR: In this article, a novel antiparallel-connected thyristor scheme for feeding highly inductive loads, such as the field of dc machines, alternators, is described and the choice of the circuit element values based on this analysis is also detailed.
Abstract: A novel antiparallel-connected thyristor scheme for feeding highly inductive loads, such as the field of dc machines, alternators, is described. A simplified analysis of the power scheme is described and the choice of the circuit element values based on this analysis is also detailed. Transient analysis of the power circuit is carried out using a general-purpose power electronic converter simulation program, named ATOSEC I, and is compared with experimental waveforms. The suitability of the proposed scheme is demonstrated in the case of a reversible dc drive based on the familiar Ward-Leonard scheme. The performance specifications of an experimental reversible drive scheme are given.

2 citations