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This paper describes the modeling and simulation of a generator system using an efficient, high-speed, high power density generator that generates up to 1 MW of high voltage DC electrical power continuously and can be used for aerospace or land applications requiring large power and compact installations. This generator system simulated comprises a brushless wound field electric machine, a generator control unit (GCU) and a bridge rectifier. The purposes of the model are: obtaining simulation results to predict the behavior of the generator system during operational transients, characterizing the power quality and selecting the filters, and tuning the control parameters of the GCU.

This paper studies the technical characteristics of a start system for aircraft engines. By using the latest improvements in power electronics and digital controls this system eliminates the conventional Air Turbine Starter (ATS) or DC starter by driving the generator installed on the engine as a motor to achieve the start. The presented start system enables a completely new architecture in today's modern and efficient aircraft using the More Electric Architecture (MEA), since bleed air is not required to start the main engines. The MEA increases the overall efficiency of the aircraft by electrically driving the Environmental Control System (ECS) and other major systems such as anti-ice, landing gear, hydraulics etc. This start system eliminates the ATS and its equipment (bleed valve, clutch) for the larger engines or the DC Starter, while providing a start where the engine is accelerated up to 80% idle speed vs. 50-60% provided by the previous Starter.

This paper describes the design and the main technical characteristics of a new Start System for an Aircraft Auxiliary Power Unit (APU). The system eliminates the one battery, dedicated for APU starting, the DC Starter and its Clutch Assembly, by driving the generator installed on the APU as a motor to achieve the start. This new system extends the APU life by providing a faster start, assisting the APU acceleration up to 8,400 rpm and maintaining lower engine temperatures during start. The battery voltage control feature and the option of using AC power for start, to save battery power and extend battery's life is another advantage over the classical DC.