OLIVEIRA, J. A. R. M.; http://lattes.cnpq.br/1351708698408624; OLIVEIRA, Jonas Agápito Rodrigues de Medeiros de.
Résumé:
These days the loads are more and more non-linear and it causes load currents to be
non-sinusoidal. The main will be damanged by the pulsant power fowing, and so the other
loads.
Diferent kinds of loads have been feeded by a alternade current main, through a direct
convertion sistem (rectifiers, direct ac-ac converters) or indirect sistem (indirect ac-ac
converter). These sistems are non-linear loads, witch generates non-sinusoidal main currents,
damaging the utilization by the user. A way to minimize this bad efects is the use
of active rectifiers, making the load current to be quasi-sinusoidal and reducting reactive
power flowing on the main. And to ac loads, ca-ca converters must be used, where active
rectifires, in the first stage, must sorve de inverter, in the second stage. At this way, the
main will see always linear loads, and any load will be feeded by sinusoidal sources.
This work proposes a ca-ca converter topology where a open-loop unidirection three
level three phase reducted componenetes active rectifier is conected directly to a three
level three phase convencional inverter. The converter is mained provide sinusoidal and
THD reducted current in the rectifier entrance and THD reducted voltage provided by
the inverter. The open-loop control on the rectifier provides also simplicity and the PWM
proposes to the inverter let it free to use any conventional machine control schema.
Is shown in this document theory analysis and simulation and experimental results to
each stage of the converter operating in stand alone and to the complete converter.
