Development of Fuel Control System for More Electric Engine

Abstract

This paper describes the experimental rig test result and an investigation into issues of system stability and pressure oscillation transmission in the MEE (More Electric Engine) fuel system. This system employs an electric motor-driven pump and directly meters the fuel flow based on the motor rotating speed. The MEE is a system architecture concept for the aircraft turbine engine that reduces fuel consumption and environmental load while improving safety, reliability and maintainability. The improvements were demonstrated by conducting a feasibility study of MEE system for small sized turbofan engine [5, 6]. The authors also conducted an experimental rig test showing capabilities in terms of fuel-metering range, accuracy and response [7]. The capability of the feedback loop control under the engine start condition was shown by the result, but meanwhile, pressure oscillation under the higher fuel flow condition was also observed. The authors repeated the rig test to investigate its root cause. This paper describes the study, which investigates the characteristics of the MEE fuel system and seeks stable control methods under conditions of higher pressure fluctuation, higher instrumentation noise or applying worn gear pump. The paper also describes the study of the pressure oscillation transmission from pump to engine combustor, which may damage the engine combustor and structures. As a result of these studies, a novel control method for the MEE fuel system is proposed, with improved oscillation stability.