Combined modeling of supply interruptions and voltage dips in a smart grid scenario

Modeling of supply interruptions and voltage dips caused by component failures and scheme reconfigurations in an electrical distribution scheme is considered in a Smart Grid scenario. Explicit reference is made to a MV/LV transformer substation supplying an industrial load. The modeling difficulties due to the contemporaneous presence of fast switching actions together with slow repair procedures are discussed. A simple technique based on the decomposition of a complete Markov model, fully describing the system is presented. The different simplified models resulting from the decomposition are solved sequentially. The application to the MV/LV substation shows the technique suitability. The importance of accounting for voltage dips and short interruptions further than for long interruptions is also evidenced. This is a consequence of the ability of such brief duration disturbances to cause damages of longer duration such as industrial process shut-down.