Design of Two-Degree-of-Freedom Turbofan-Power-Ratio Control System for Micro Turbojet Engine

Control of gas turbine engines is a safety critical aspect of the industry, regardless of power turbines or aviation power plants. Moreover, modern turbine control systems implement additional features that allow efficient operation throughout the widest possible range, reduction of crew workload by enabling automated sequences, furthermore it can provide sophisticated diagnostic capabilities as well. The present article focuses on an irregular combination of a micro-scale turbojet engine that is intended to be controlled via Turbofan Power Ratio, originally developed for high bypass ratio turbofans. The primary aim of this paper is to prove through measurement data that the proposed parameter is suitable for the intended control. As a secondary goal, a two-degree-of-freedom PID is designed based on identification of a particular micro turbojet with a fixed exhaust nozzle available at the Author's Department. The paper includes a comparison with previous control laws and highlights the benefits of the newly developed control system.