Análisis de las defi niciones de Análisis de las defi niciones de desequilibrio desequilibrio de tensión de tensión en los sistemas de potencia

Abstract

Documents recently published by IEC and IEEE standard have adopted as a measure of voltage unbalance the relationship between negative and positive sequence components. However, other imbalance indices are usual in practice, such as voltage unbalance defined by the National Electrical Manufacturers Association, NEMA, in USA, or those based on the maximum deviations of average voltages proposed by IEEE in its publications. This article analyzes the different defi nitions of voltage unbalance introduced in several standards over the last decades. Thus, a comparative assessment of different defi nitions versus the imbalance factor adopted by IEC has been carried out. This index is considered the true imbalance in this text. To do this, several simulation and experimental setups have been designed. The results obtained have allowed the importance of adopting a definition to achieve a correct imbalance measure in the characterization of voltage asymmetry in electricity networks to be highlighted.