BAHIA, F. A. C; http://lattes.cnpq.br/9798218730942618; BAHIA, Filipe Antônio da Costa.
Résumé:
This work focuses on the study of AC-DC converters unidirectional with reduced number
of switches controlled who use a two-phase machine functioning as generator for supplying
power to a load. In this context, In this context, six rectifiers configurations are
investigated , two topologies that employ switches of the type IGBT and and four others
who adopt bidirectional switches in current and voltage. The configurations that make
use IGBTs have four legs consist of eight diodes and four controlled switches, while the
topologies using bidirectional switches have two or three controlled switches connected
between the converter’s legs.
For all studied topologies, the dynamic models and/or analyzes of operating modes, developed
the control and PWM strategies are presented. With regard the PWM strategies,
for topologies using IGBTs, it applies once sine-triangle modulation in function of the
polarity of the phase currents, topologies that use for bidirectional switches, it employs
space vector modulation with sectors defined according to the direction of the currents.
The control system operates regulating the DC-link voltage and and it uses a synchronization
method that has the purpose to reduce distortion in the current at the zero crossing,
ensuring currents of sinusoidal machine with high power factor.
For comparison and performance evaluation of the topologies investigated are used two
main criteria: harmonic distortions analysis in the current waveforms and semiconductor
switching and conduction losses. Finally, simulation and experimental results are presented
and discussed for the validation of the studied topologies.
