Power Quality Assessment in a Microgrid System using Signal Decomposition Techniques

In this work, a report on different signal decomposition techniques (time-frequency TF) applied to power quality (PQ) events are provided. In a system with hybrid renewable sources, nonlinear load points and capacitor bank, the operation of individual units can affect the quality of the signals while switching from one state to another or during varying operating modes. In this context, the grid operating state is another concern which cannot be neglected. Considering the different possible operating states and operating conditions of system and individual equipment, different signal decomposition techniques are selected and the responses for individual events are analyzed. The Empirical Mode Decomposition (EMD), Ensembled Empirical Mode Decomposition (EEMD) and Intrinsic Time Decomposition (ITD) techniques are selected for signal analysis. Cases such as noise, harmonics, voltage sag, and nonlinear load switching events are simulated and presented in the work.