Self-enhancing model-based control for active transient protection and thrust response improvement of gas turbine aero-engines

Abstract

A self-enhancing active transient protection (SeATP) control approach using model-based strategies is proposed for gas turbine aero-engines, which aims at pro-actively handling surge margin limit and turbine entry temperature limit over the life cycle. The feature of SeATP is a bank of self-enhancing loops with periodically updated controller parameters for different flight cycles. This is realized by an off-line gain tuning via global optimization approach. Additionally, a sensor-based baseline controller and a model-based active transient protection (ATP) controller (with fixed gains) are developed as comparison bases. Numerical simulations for the examined controllers are carried on a validated aero-thermal turbofan engine model for idle to full-power acceleration tests in Matlab/Simulink environment. Simulation results demonstrate that ATP controller owns a considerable thrust response improvement for both the new engine and a severely degraded engine, compared with the baseline controller. Moreover, the proposed SeATP controller ensures a 65.77% recovery rate of thrust response deviation caused by the ATP controller for the degraded engine. Particularly, a low transient surge margin trajectory and a high turbine entry temperature route are fulfilled by the SeATP controller. SeATP controller also shows better robustness performance for degradation variation than ATP controller. Hence, the SeATP control performance is confirmed.