Minimisation of voltage sags-induced financial losses in an Indian distribution system using a static VAR compensator

Abstract

A voltage sag can cause tripping of sensitive electronic equipment and cause production stops in many industries. Therefore, it can have significant economic consequences for different types of industries. Flexible AC Transmission System (FACTS) devices were originally developed for transmission networks but similar ideas are now starting to be applied in distribution systems. FACTS devices have become popular as a cost-effective solution for the protection of sensitive loads from a voltage sag. This paper, therefore, presents the modelling of the FACTS device Static VAR Compensator (SVC) to minimise voltage sag-induced financial losses. The overall system financial losses due to a voltage sag could significantly be reduced depending on the type of FACTS devices used. The short circuit analysis approach is used to incorporate the effect of these devices on financial losses. Voltage sags produced by balanced and unbalanced short circuits are analysed by means of a new analytical approach using the system impedance matrix (ZBus), which incorporates SVC. Case studies based on a real Indian distribution system are used to illustrate the modelling method and the effectiveness of these devices in voltage sag mitigation.