Modellering av reserv- och nödkraftsystem i JAS 39 Gripen
Simulation is a vital tool during development of JAS 39 Gripen, since money and time can be saved.The Auxiliary and Emergency Power System, AEPS, is a subsystem of the secondary power system in Gripen. It has the function of providing the aircraft with electrical and hydraulical power before activation and after deactivation of the main engine. The system also functions as backup in case of a safety critical problem in the main power supply system. The system basically consists of a control unit and an auxiliary gearbox. The gearbox is driven by an air turbine. An auxiliary generator and a hydraulic pump are mounted on the gearbox to provide the aircraft with electrical and hydraulical power. The air?ow to the turbine is regulated by an Air Modulating Valve, AMV.This report describes a new model of the AEPS. The model encompasses the logical control unit and a physical description of AMV, air turbine, auxiliary gearbox, auxiliary generator and the auxiliary hydraulic pump. The logical model is connected to the physical model whereby simulation of the whole system is made possible. The model is implemented in Matlab/Simulink.This work provides a complete model of the AEPS which enables simulation of the dynamical processes. Veri?cation was done by comparing simulation results with measurements from the real physical system. Satisfactory results are achieved, especially for inlet pressure for the air turbine and the speed of the auxiliary generator.