Application of Fuzzy Systems in Power Quality: Diagnosis of Total Harmonic Distortions

This paper proposes a system which estimates the total harmonic distortions (THD) of voltages and currents and evaluates their impacts on power quality through a fuzzy system. Firstly, voltages and currents are measured by sensors and their root means square (RMS) values are calculated in the online by means of the recursive Fourier discrete transform. Therefore, instantaneous and average values of THD of voltages and currents are computed based on IEEE Standard 1459-2010. The average values of estimated THD indices are provided to the fuzzy system that accomplishes the power quality diagnosis based on several well-known power quality standards. The performance of the proposed system was evaluated in an experimental platform in laboratory considering power quality disturbances originated by linear and non-linear loads.