This is a PhD dissertation. The work presented in this monograph was carried out at the Department of Power Electronics and Electrical Machines, Faculty of Electrical and Control Engineering at the Gdansk University of Technology. Developed during the research models of brushless synchronous generator ware verified using FEM based simulations and measurements conducted on the prototype generator. The main focus of the research was toward a brushless synchronous generator in variable frequency modern more electric aircraft power systems. The generator prototype was developed and its performance was analyzed with the focus on the higher rotational velocity of the prototype components and the generated power quality. For this FEM based and circuit models of the generator ware developed and the machine performance was measured and simulated. The proposed circuit model allowed for the inclusion of nonsinusoidal spatial distribution of the magnetic flux along the air gap which in turn allowed for simulation-based power quality analysis.