Modelagem e simulação do sistema de controle de uma micro-turbina a gás

Abstract

Micro-turbines are distributed generation devices that have shown a notable potential in electric energy market in Brazil. This technology presents the characteristic of operating with several kinds of fuel, like kerosene, diesel, alcohol, natural gas, biodiesel and biomass gasification gas. Modeling and simulation tend to create a tool for redesign the micro-turbine project when it operates with fuel of low heat value. Acquisition data system and instrumentation were mounted in the tests laboratory to measure, store and analyze the micro-turbines control systems variables. A model found in the literature was used as initial reference, and models were validated for two operation modes: Grid Connection and Stand Alone. The model parameters were obtained using a MatLab Toolbox for Systems Identification called Ident, where three types of models were validated: ARX, ARMAX and Box-Jenkins. Ident uses Minimal Square Estimator to transform experimental data in transfer functions in z domain. Programs were developed to transform it into transfer functions in s domain using Zero Order Holder. Experimental data for models validation were obtained from a Micro-Turbine placed in the Gas Turbine and Gasification Laboratory of the NEST (Thermal Systems Excellence Group) – UNIFEI. The obtained models presented an acceptable performance if they are considered as an initial proposal subjected to improvements.