Adjustable speed drives supplied with unbalanced voltages: Study under complex voltage unbalance factor parameter

The different unbalance definitions applied to three-phase networks are presented shortly, and the unbalance causes and effects on induction motors and ASD are commented. The behavior of an ASD is analyzed when it is fed by an unbalanced voltage centering the attention on the characteristic and non-characteristic harmonic, rms values, K-derating factor, etc This analysis is made on an ASD simulation and on experimental results. It is concluded in the necessity to center this analysis type not only considering the amplitude relationship of the negative and positive sequence components but also considering the relationship between both phases.