Influência das conexões dos transformadores de potência na propagação dos afundamentos de tensão pelo sistema elétrico

Abstract

The purpose of this work is to analyze the influence of all types of connections transformers on the propagation of voltage sags on electrical system. For analyzes the phenomenon, it was modeled on the ATP - Alternative Transient Program - a standard IEEE 14-bus system and a sags generator, which is able to generate any kind of voltage sag with any variations of the magnitude and phase angle. The influence of transformers winding connection in the propagation of voltage sags can be observed when the disturbance contains zero-sequence components and the winding connection block the flow of this sequence. In some voltage sags, the quantities of zero sequence components are not involved because the origin of the short circuits does not involve the ground. In these cases, the influence can be expected in consequence of phase shift introduced by some transformers. Finally, the influence can also occur due to the combination of these two types of transformers respectively Voltage sags propagation through the most differentiated kinds of transformers connections result in sags with very different characteristics from those that originated them.