Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
MODELLING A PNEUMATIC SPEED GOVERNOR USING ELECTRONIC PRESSURE VALVES AND DIRECTIONAL VALVES.
Submission Author:
Gregori Picolotto Conterato , SC
Co-Authors:
Gregori Picolotto Conterato, Talles Augusto Bragagnolo Spada, Vinícius Vigolo, Leonardo Augusto Weiss, Rafael Haisi Klita, Leonardo Lino Leoncini, Pedro de Araujo, Victor Juliano De Negri
Presenter: Gregori Picolotto Conterato
doi://10.26678/ABCM.COBEM2019.COB2019-1315
Abstract
In this paper, a mathematical model of a pneumatic system is presented as an alternative for the hydraulic systems used to control the guide vanes mechanism in francis turbines of small hydropower plants. The pneumatic technology has lower acquisition cost, good power-to-weight ratio, easy to use, low maintenance and cleaner operation (does not uses oil). The system was designed to operate with components that are widespread in industrial applications, which have a good quantity of manufacturers, reliability, and availability of replacement parts. The main components of the system are an asymmetric pneumatic actuator, an electronic pressure control valve, a standard directional control valve and a pressure reducing valve. The control of the system is made by a P.I.D. Controller that controls the electronic pressure valve and an algorithm that controls the directional control valve, commutating the last one according to the load profile. The simulation is carried out in the software Matlab Simulink, using the parameters provided by the company Reivax S/A Automation and Control of a Francis turbine that has 438 kW of generating capacity and net height of 15.5 m. To achieve the precision required by the international standards of the application, the main state variables and nonlinearities of the pneumatic system are modeled, obtaining the maximum error of 1.05 mm or 0.8 % of the actuator's stroke.
Keywords
Pneumatic Drives, Position Control, Speed Governor, Francis Turbines, dynamic modelling
