Monitoring Power Quality in Microgrids Based on Disturbances Propagation Algorithms

The paper shows how the surveying of power quality in microgrids working under unbalanced harmonic distorted operating states with possible voltage dips and voltage swells existence can be accomplished implying a small amount of time and measurement activities. The surveying methodology uses the disturbances propagation phenomenon to determine the power quality indices in all of interest nodes of the microgrid utilizing the voltages and currents characteristics in one or several strategic nodes. The disturbances propagation is based on the sequence component theory applied for all detected harmonics and for the microgrids components. The proposed surveying methodology was implemented in a virtual instrument capable to acquire the voltages and currents waveforms, to analyze them in order to identify the disturbances characteristics, to calculate the disturbances propagation and display the power quality indices in all of interest nodes of the microgrid. The virtual instrument was tested using several microgrid topologies and scenarios.