Hybrid plant modeling for discrete controllers analysis: A case study

Having into account a higher complexity and, also, higher demands in what concerns dependability of Automation Systems controllers, the task of controllers design is a very hard and complex task. In order to help the automation systems designers, there are some analysis techniques that allow obtaining more robust and dependable controllers. Simulation is one of these techniques. In this paper it is intended to show, first, how the Simulation of a closed-loop system (controller and plant) allows an increasing in dependability of the controller and, second, to define conditions (because all the plant is modeled) of danger situations for the system behavior; more specifically, the parameters that can lead the system to a dangerous situation. The system is composed by a hybrid plant and a discrete controller. In this paper, also the suitability of Modelica modeling language is highlighted in order to model complex closed-loop systems, especially when the plant of these systems is composed by different technologies.