Characterization of Voltage Sags and its Mitigation Using Custom Power Devices in Emerging Power System

Voltage sags are short duration reductions in RMS voltage caused by short circuits, overloads and starting of large motors. Voltage sag has much a global problem. For proper analysis and mitigation of voltage sag, their characterization is important to be analized. The magnitude and duration are the main characteristics of voltage sag. In this paper voltage sag and their characteristics have been presented in a comprehensive way. This paper analized how voltage sags occur, what their characteristics are and the impact on equipments behavior for different conditions. Through voltage source converter, it is possible to compensate for the drop in system voltage or even to temporarily take over the supply completely. The shunt and series controller are based on power-electronic voltage source converters. For a full compensation both reactive and active power are needed. Not only for deep voltage sags but it is also possible to compensate the drop in voltage magnitude by injecting reactive power only