Detection, analysis, and mitigation of voltage sag in renewable energy-rich power grids

Amongst all power quality (PQ) problems, voltage sags/dips are the most common occurring disturbances, which can cause significant failure in the customer equipment. This thesis contributes to three areas of voltage sag analysis: First, it contributes to the development of new innovative analytical formulae for the predictive analysis of the single event characteristics (SEC) of a voltage sag based on the system electrical parameter. Second, it contributes to the development of a novel time-frequency domain signal-processing tool for the automatic detection, analysis, and mitigation of time-varying PQ disturbances (PQDs). The developed method is referred to as the automatic segmented Hilbert-Huang transform (SHHT). Third, it contributes to the development of a cost-effective mitigation scheme for voltage sag events with and without the presence of distributed generations (DG)/renewable energy resources (RES).