A Novel Algorithm for Accurate Frequency Measurement Using Transformed Consecutive Points of DFT

摘要

A novel algorithm based on discrete Fourier transform (DFT) to estimate the frequency of power system is proposed. The algorithm that we called transformed discrete Fourier transform (TDFT) involves transforming consecutive points of DFT of voltage signals to reduce the leakage components. The algorithm has the following merits: It is immune to inter-harmonics as well as harmonics; it has simple and easy implementation; and it has good performance both in steady and dynamic states. What is more, it can keep high precision in a very wide frequency deviation range, for example, 40–60 Hz. Simulation experiments validate this algorithm can track power system frequency precisely.