Diseño y verificación de sistemas de control On-Off, PI y PID sobre el proceso de deshidratación térmica de tomate.

Abstract

The purpose of this degree work was to design and verify the control systems On-Off, PI and PID on the tomato thermal dehydration process. In the process of dehydration, it was known that tomato is dehydrated at a temperature of 60 ° C within a period of 10 hours. In thermal systems the characteristic equation of the plant makes reference to a type 1 system with a response of an exponential nature; for modeling of the plant, the classical identification method was used by applying a step signal as a signal test. In the design of the On-Off controller, a control action with hysteresis was considered to avoid excessive switching. System tuning constants with controller PI and PID were obtained by applying the Ziegler-Nichols experimental method, as well as the root locus method and Padé's approximation giving a more accurate equation characteristic for both cases. 4 parameters were raised to verify the performance of the thermal system with the different types of controllers, it was obtained as a result that the PI controller: provides a power consumption of the electrical system of 158.2W; is stable according to the analysis of the stability curve in steady, transitory and absolute state; presents the best appearance while preserving its ideal physical characteristics of a correct dehydration and a dry weight of 13g was obtained, so it was shown that this controller is the most suitable for the proposed project as well as being low cost compared to dehydrators that meet similar operating characteristics. It is recommended fine-tune the PI controller by trial and error method, in addition to implement a hybrid system with the help of renewable energy that generates greater energetic savings.