Modified Petri Nets for Hybrid Systems Modeling - a Case Study


In this paper we deal with the problem of modeling and simulation a DC electric drive system using a Hybrid Petri Net formalism, considering that the electric drive is a hybrid system which switches between its states under the occurrence of generic and non-generic external events. The synthesized topology is called a Modified Hybrid Petri Net and is a hybrid model that combines both differentials and discrete Petri Nets dynamic and enables us to simulate and to analyzing the behavior of DC electrical drives in different operating regimes due to the particularities imposed by the load of electrical motor. A real application case was finally considered; different scenarios were analyzed, depending on the nature of the engine load and the specific working conditions. The correctness of the initial model was verified by simulation and, also, by comparison of the results with those obtained experimentally, on a physical model. The modified Petri Nets model is carried out with an available software Visual Object Net ++, which allowed at the same time the synthesis of a hierarchical Object Petri Net structure. All models obtained through this method had been synthesized through an ascendant technique, around a central core, by adding new elements according to the studied processes. images