• diode rectifier
• Matlab/Simulink
• three-stage synchronous generator
• average model
• Amesim

The main purpose of this thesis is to model an aircraft synchronous generator feeding a diode bridge rectifier with a DC load. The system is characterized by three separate brushless synchronous alternators (permanent magnet generator, exciter and main generator) connected in cascade and mounted on the same drive shaft, each loaded with a diode rectifier. A control unit is used to guarantee a specific DC voltage on the load terminals by controlling the excitation voltage of the exciter.
Different models of increasing complexity have been developed and compared. Behavioural models, implemented in the simulative environment AMESim, are detailed models that consider the non-ideal behaviour of the diode rectifiers, a consequence of the large value of the generator impedances. Due to time- and memory consumptions of behavioural model simulations, Functional model has been implemented in Matlab/Simulink. This ‘average model’ is used to predict the dynamic system behaviour and to linearize the system, allowing a more detailed study of the controller design in future research activities.