Abstract
In this paper we propose an alternative method using a graphical approach to study the dynamic behaviour of a class of photovoltaic systems based on its bond graph. A new working environment for simulation of such PV system using the 20sim package under the windows environment was used. This PV system is composed of a PV generator, DC-DC converter and DC motor. A bond graph model taking into account the non linearity of the current-voltage (I-V) solar generator characteristic and using an averaged model of DC-DC converter, has been built. From this bond graph model we deduce the state equation of our PV system. After that, we simulate the time response and we compute the stabillity domain. The results showed the existence of non minimal phase response caused by positive real roots in the transfer function numerator. This situation leads to mechanical problems hardly bearable by electromechanical machines. A control plan was determined in order to limit the operating voltage area of PV army in which the problem quoted above is avoided.