Marius Zainea

Formal approach to compute hybrid automata models for linear physical systems with switches

This paper considers the computation of a hybrid automaton that models the behaviour of a switching linear physical system using energy considerations. The system is represented in a compositional way with bond graphs that include switches. In a first step the switches are considered from a functional point of view. This allows to determine the locations that are associated to consistent configuration of switches, the continuous activities and the jumps. In a second step elementary models of switches are introduced and allow to determine the invariants and the guards of transitions. The approach is exemplified with a simple electronics circuit

Stabilizing control for power converters connected to transmission lines

This paper proposes a switching control strategy for the set-point stabilization of a power converter connected via a transmission line to a resistive load. The strategy employs a Lyapunov function that is directly based on energy considerations of the power converter, as well as of the transmission line described by the telegraph equations. The proposed stabilizing switching control still allows a certain freedom in the choice of the control law, a comparison between a maximum descent strategy and a minimum commutation strategy being discussed on a simple example.

A double resonance generator simulation using a hybrid approach

By using a hybrid approach the authors present the modelling of a double resonant DC/DC converter. This kind of generator is used for medical imagery applications, requiring high tensions, typically 40 kV to 200 kV, associated with high powers (about 100 kW). The proposed methodology can constitute an effective method allowing a structured and systematic approach of the dynamic systems modelling

The open-loop control for the start-up of a double resonance converter using a hybrid systems approach

In the power converters area there is a growing interest in applying hybrid systems techniques for modeling, analysis and control. This paper proposes the open-loop control for the start-up of a double resonance converter using an offline nonlinear constrained optimization, where the evaluation of the cost function is obtained via simulation. In this way, difficulties related to the complexity of the system are tackled due to the exhaustive behavior modeling.

Modeling and control of building heating using wood burning boilers

This paper deals with the modeling and control of a heating production system designed to supply hot water that is afterward used for the actual heating of an office building. The modeling part emphasizes the constraints writing, based on the assumptions made for the boiler model as well as the well-posedeness conditions concerning the whole heating production model. The control part deals with finding a solution in a model predictive control framework, where, given the hybrid and nonlinear dynamics characteristics of the model previously determined, an online implementation based on the simulation model is used.

Modélisation des systèmes physiques à commutations par approche énergétique : Application à un convertisseur DC-DC

This paper deals with two formal modelling approaches of switching physical systems, based on energetic considerations. The modelling of the continuous part is first presented followed by the determination of the automaton of the non controlled system. Both approaches are based on an ideal switching model leading to a variable topologic representation. The first one uses bond graph formalism and the second one, is based on interconnection graphs and hamiltonian formalism. An application on a DC-DC converter illustrates these two approaches.

A NEWTON METHOD FOR CYCLE DETERMINATION OF LINEAR PHYSICAL SYSTEMS WITH SWITCHES

Abstract The goal of this paper is to apply a newly developed Newton method for the cycle determination in the case of linear physical systems with switches. The difficulty consists in the fact that, in the general case, the dimension of the dynamics equation is different from one configuration of the system to another. The structural properties of the considered model of linear physical systems with switches can be used to simplify the cycle computation original scheme.