Research On Aircraft Power Plant Model Design And Transition Control Law

With the increasing requirement of modern aircraft to performance, stability, research cost anddevelopment period of modern aero-engines, the propulsion system simulation technology has beenmaking great progress. Aero-engine modeling and transition control law are discussed in this paper,including APU modeling, turbo-shaft engine modeling and turbo-shaft engine acceleration control.First, in the case of lack of component characteristics the APU grey model is established by thegrey modeling method with limited test data. The modeling requirement is obtained by analyzing thestructure characteristics and operation principles. After analysis of rig test data and thermo dynamicalcomputation, a grey model of APU has been carried out, and then the digital simulation platform ofAPU is developed. The digital simulation and hardware-in-loop simulation were carried out.Comparing with the rig test data, the simulation results, which achieve the steady-state error less than3%and maximum dynamic error less than5%, show that the modeling methods meet the designrequirement of aero engine control system.Secondly, startup model for turbo-shaft engine is established. The main componentscharacteristics of the turbo-shaft engine are predicted by characteristics expansion and characteristiccalculation due to unavailable characteristics, and the component-level above-idle state componentmodel is established. The component-level startup model is developed with the consideration of theinfluence of combustion efficiency variation and heat transfer. The digital simulation was carried out.Finally, the research of turbo-shaft engine acceleration control law is carried out. After analyzingthe limits of turbo-shaft engine transition state, the optimized fuel schedule was obtained using theSQP, the simulation result show the schedule is satisfying. Based on the SQP, the research on the gasturbine inlet temperature of LEC was discussed, the simulation of LEC reduces the gas turbine inlettemperature and the time on the max stay time gas turbine temperature.