Networks composed of switches (S) and linear RLC elements are formulated by state-space equations in which the switches S are dealt with as the voltage sources V_s ( = 0) for closed switches and current sources i_s ( = 0) for open switches. The equation associated with the change of switching combinations (mode change) is modified. The solution of the jump of the state vector which occurs at mode change is made clear in the distribution sense. The invariance of state space under mode change is discussed, and the concept of switch controllability and observability is introduced to solve this problem.

A method for the formulation and solution of circuits composed of switches and linear RLC elements

A novel approach for power converter simulation in the electromagnetic transients program (EMTP) is presented. It is based on simultaneous interfacing of a converter simulation module with the EMTP network equations. Hybrid analysis, demonstrated to be more general than the compensation method, is used to model the nonlinear converter module network. The procedure used to formulate hybrid port equations is general and can be used for any converter module network with nonlinear branch functions. The valve model selection has no theoretical restrictions, and the particular case of valve modeling by ideal switches is simple to accommodate. The new approach is more general and efficient than the standard EMTP method for power converter simulation. Modularity permits incorporation of dedicated initialization procedures and programming of digital control schemes. >

Power converter simulation module connected to the EMTP

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.

https://hal.archives-ouvertes.fr/tel-01203184/document

Modelisation des systèmes de conversion de l'énergie électrique dans un contexte pluridisciplinaire

In recent years there has been an increase in the types and usage of AC variable speed drives. However, as the complexity of these systems has increased, so has the occurrence of problems which are...

CASED: A simulation package designed for variable speed drives

The authors discuss issues specific to power electronic simulation and formulate a simulator specification to meet these needs. To show how this specification can be met, some examples are given of the use of the present version of the Sydney University power electronics simulator (SUPES) under development at the University of Sydney, Australia. The first example is the use of ideal switch models in a situation where an analytical solution is not possible. The second is the simulation of control loops and involves a mechanical system. The final example involves a macro-model of a transistor for a fault analysis problem. All examples are simplified to give a clear demonstration of the techniques discussed, but they could be made more accurate, if required, at the expense of increased runtime. >

SUPES: Sydney University power electronic simulator

The purpose of this article is to develop an efficient model for the analysis of a three-phase converter. An algorithm for the generation of a modified proper tree and fundamental cutset matrix from a network graph is developed, which utilizes much less computer storage space and computation time compared to the classical methods. A three-phase rectifier bridge with its associated protective circuits is considered and the results obtained from the developed technique are discussed.

Topological Model for a Three-Phase Converter

A new procedure for formulating the state equations for RLC circuits without proper trees is presented. This method would force the network to have a proper tree; thus, obviating the necessity of finding the inverse of a general L, C matrix (a matrix which is not diagonal), and saving the memory and time requirements for computer implementation.

K. Sankara Rao

Papers

Topological Model for a Three-Phase Converter

Formulation of state equations for RLC networks with modified proper trees