A Novel Approach for Stall Prevention and Rotation Speed Limiting in a Min–Max Controller Structure

Abstract

This paper proposes a novel approach for the implementation of limit controllers used for stall prevention and rotation speed limitation of a single-spool jet engine. In this approach, the protection requirements regarding the rotation speed are achieved through the use of a filter applied to the reference that will be sent to the power management controller of a Min–Max structure controller. The main controller variable is the turbine’s core rotation speed. The filter chooses the most appropriate reference value aiming at respecting the engine established limits, such as the stall margin and the maximum rotation speed, during transient and steady-state behaviors. The Min–Max compensators structure chosen for the implementation of the controllers is proportional–integral with Back Calculation as the anti-windup technique. Simulation model of a GE-J85-13 single-spool jet engine has been used to test the new approach and compare it to the more common Min–Max structure, where each controller is implemented individually. The simulation contemplates the case where a step function is applied to the power management controller, where the final value is the maximum allowed rotation speed value, at sea-level, static and standard-day temperature conditions. The simulation is repeated for different values of Back Calculation gains using both Min–Max structures, and the behavior of the GE-J85-13 engine is evaluated in each case for comparison proposes.