A Morphological Filter For Estimation of Power System Harmonics

This paper presents a new method based on mathematical morphology for accurate estimation of harmonics and detection of sub-harmonics in power systems. This method, using a morphological transform as a low-pass filter, is developed based on a well-known technique: instantaneous reactive power theory. The simulation results are presented to show the accuracy and capability of the proposed method. The extraction of a sub- harmonic component, from ferroresonant voltage of a power transformer, is also discussed as an example of the sub-harmonics detection. The calculation simplicity of the morphological operators furnishes the proposed method with ease of real-time implementation.