Modeling, simulation, and analysis of variable-speed constant frequency power conversion scheme with a permanent magnet brushless DC generator

A variable-speed, constant-frequency (VSCF) power-conversion scheme with a permanent magnet DC (PMDC) brushless generator is proposed. The scheme is completely modeled for steady state by integrating the characteristic equations of the generator, the diode rectifier bridge and the inverter, and the harmonic characteristics for steady-state performance computation. Commutation overlap effects are also included. Key performance characteristics are experimentally verified with a laboratory prototype. The excellent correlation between the predicted and experimental results confirms the validity of the model. For the purpose of filter design, harmonics of the rectified generator voltages are analytically derived. A recommendation for overcoming the low power factor on the utility side at low speeds using the forced-commutated converters is given