Eur. Phys. J. AP 21, 107–120 (2003) DOI: 10.1051/epjap:2002118 T HE EUROPEAN P HYSICAL JOURNAL APPLIED PHYSICS Developing an advanced PWM-switch model including semiconductor device non-linearities A. Ammous 1, a , M. Ayedi 1 , Y. Ounajjar 1 , F. Sellami 1 , K. Ammous 2, b , and H. Morel 2 1 Laboratoire d’ ´ Electronique et des Technologies de l’Information (LETI), ENIS, BP W, 3038 Sfax, Tunisia 2 Centre de G´ enie ´ Electrique de Lyon (CEGELY), INSA-Lyon, Bˆat. 401, 69621 Villeurbanne, France Received: 3 October 2001 / Received in final form: 29 August 2002 / Accepted: 17 October 2002 Published online: 11 December 2002 – c  EDP Sciences Abstract. The accurate simulation of power electronic systems is possible when including accurate models of the semiconductor devices, but practically not affordable. Classical ideal averaged models of the system are not suitable either. Hence, averaged models including the non-linear effects of the power semiconductor devices appear quite efficient. The proposed non-ideal PWM-switch model is a useful method for modeling pulse width modulated converters operating in the continuous conduction mode. The main advantages of the proposed averaged model are the takes into account of the non-linear effects of power devices and the possibility to estimate the dissipated power in the different circuit devices. The proposed electrical model can be applied to bi-directional converters and allows the coupling with thermal model in the power electronic system. A simple technique to evaluate the different static and dynamic parameters of the devices, from manufacturers data sheets or experimentally, is presented. PACS. 84.30.Jc Power electronics; power supply circuits – 07.05.Tp Computer modeling and simulation – 85.30.-z Semiconductor devices 1 Introduction The accurate analysis of the power electronic system be- havior is possible using semiconductor refined models. The simulation cost of these systems is unaffordable. Hence, long time range simulations need the use of simplified models of the converter called averaged models. The classical averaged models use ideal switches in- stead of semiconductor devices models. Since 1976 differ- ent methods have been presented to compute an averaged model [1–9]. Nevertheless it remains that all the methods apply the ideal representation of a converter, when semi- conductor devices are replaced by ideal switches. Then, the obtained averaged model is limited since the semicon- ductor devices non linearities are neglected. For example the dynamical power losses, the I-V characteristics, the dead time between the driving signals. In [4] the authors present a useful PWM-switch mod- eling method for DC-DC converters. The semiconduc- tor devices are supposed to be ideal. In the present pa- per we have developed a non-ideal PWM-switch model which takes into account the semiconductor non linear- ity. However a simple switching and static characteristics of these devices are considered. The proposed technique uses the manufacturers data sheet information’s or the a e-mail: Anis.Ammous@enis.rnu.tn b e-mail: kammous@cegely.insa-lyon.fr experimental evolution of the electrical waveforms in the PWM-switch, to evaluate the different devices parameters. The developed PWM-switch model can be applied to bi-directional converters which always operates in the con- tinuous conduction mode. To evaluate the proposed aver- aged model accuracy, fine simulations, using the refined model for semiconductor devices, are performed. The proposed model can be implemented in a general purpose simulation tool like SPICE. In our case we have chosen to introduce the model in Matlab simulator [10] which is an important tool where different system models (electrical, mechanical, thermal...) can be developed. The next section treat the development of the non- ideal averaged model and the technique used to evaluate the switching and static parameter of the different semi- conductor devices. The third section covers an application of the advanced PWM-switch model. The proposed sys- tem is the one phase DC-AC converter with IGBT’s. The effect of the dead time in the load current evolution is seen. Coupling the electrical averaged model to a thermal model is made and temperatures evolution are compared to the fine model results. 2 The non-ideal averaged model The average model of a converter is a simplified repre- sentation of the converter in quasi- cyclic operation, that