Fast detection of rapid voltage change events through dynamic RMS voltage tracking

Rapid Voltage Changes (RVCs) are small, but frequent RMS voltage transitions between two steady-state conditions, which can significantly affect the Power Quality (PQ) (particularly flicker) perceived by final users. Even if the IEC Standard 61000-4-30:2015 explicitly includes a proper RVC definition as well as a detection algorithm, the characterization of this kind of PQ events is still quite unexplored in the scientific literature. In this paper, the root mean square (RMS) voltage estimator adopted in the IEC detection algorithm is compared with a weighted least square (WLS) estimator originally conceived for Phasor Measurement Units (PMUs) and able to track voltage variations within each observation intervals. Multiple simulation results show that the WLS technique generally ensures faster RVC event detection and it is accurate even in the presence of harmonic distortion.