Se inicia temporada de seminarios LCDA'05.
Charla "Analysis of a Multi-Cell Converter under Unbalanced AC Source."
El señor Marcelo Perez Leiva, Msc y candidato a Doctor en Ingeniería dará una conferencia titulada "Analysis of a Multi-Cell Converter under Unbalanced AC Source" a realizarse en las dependencias del LCDA el jueves 24 de marzo a las 17:00 horas. El Msc. Marcelo Perez es autor de varias publicaciones en revistas ISI y conferencias internacionales. Este trabajo ha sido aceptado para publicación en la conferencia PESC'05.
Multi-cell converters offers very useful characteristics such as improved energy quality at the ac system and motor side, a reduced torque pulsations, fulfill the input current harmonic content recommendations and presents a high power factor even at low levels of load. They also feature a high level of modularity and present a high reliability. Moreover, this converter does not produce electromagnetic interference or common-mode voltages and therefore, it is appropriate for large volt-ampere and high voltage motor drives. However under amplitude unbalances at the AC supply, the input multi-pulse transformer gives unbalanced secondary voltages in both magnitude and phase, which added to the effect of amplification of unbalanced currents in the diode based rectifier, a deteriorated overall input current is obtained. On the other hand, the current injected by the rectifier into the DC link produces a distorted DC voltage waveform, which in turn deteriorates the motor voltage. In this work, using symmetrical components, it is possible to analyze the effect in each of these stages by quantifying the amount of unbalance and distortion produced in current and voltage waveforms. Besides, this analysis provides a design guideline to calculate the DC link capacitor size necessary to reject off the effects of unbalances in the AC supply. Simulation results confirm the theoretical considerations.
|Msc. Marcelo Perez Leiva. |