Power System Frequency Estimation by Using a Newton-Type Technique for Smart Meters

This paper proposes a single-phase grid voltage fundamental frequency estimation technique for smart meters. The technique relies on a nonlinear Newton-type algorithm and a recursive differentiation filter (NTA-DF). It can reject the negative effects caused by dc offset, harmonics, notches, and spikes. When compared with a NTA technique based on least-squares (NTA-LS), the proposed one reduces matrix dimensions, avoids matrix inversion, and is computationally efficient, thus requiring less hardware and associated cost for real-time implementation. Moreover, unlike the NTA-LS technique, the NTA-DF shows less sensitivity to the presence of harmonics. Simulation and experimental results are presented to verify the performance of the proposed technique.