Relative Gain Array Analysis of a Solid Oxide Fuel Cell Gas Turbine Hybrid Plant

Abstract

This paper presents a relative gain array (RGA) analysis of a simulated solid oxide fuel cell/gas turbine plant, based on a multivariate empirical formulation of a 300 kW hybrid system. The HyPer test facility at the National Energy Technology Laboratory, served as the test bed for deriving frequency response data and subsequent multivariable model of a direct-fired, recuperated hybrid cycle plant. Through the modulation of various airflow bypass valves, magnitude and phase data are used to formulate transfer function (TF) equations that describe input/output system interaction. A frequency dependent RGA calculation of the empirical TF matrix provides a means of quantifying the degree of coupling between system inputs and outputs for the configuration studied. Various input/output interaction time scales are obtained to identify frequencies where fully developed system coupling occur. Analysis of the RGA matrix leads to a better understanding of the inherent properties and the hybrid configuration, and can serve as a validating tool to existing analytical RGA calculations of similar types of hybrids.