Instantaneous Frequency Estimation in Unbalanced Systems Using Affine Differential Geometry

Abstract

The paper discusses the relationships between electrical quantities, namely voltages and frequency, and affine differential geometry ones, namely affine arc length and curvature. Moreover, it establishes a link between frequency and time derivatives of voltage, through the utilization of affine differential geometry invariants. Based on this link, a new instantaneous frequency estimation formula is proposed, which is particularly suited for unbalanced systems. An application of the proposed formula to single-phase systems is also provided. Several numerical examples based on balanced, unbalanced, as well as single-phase systems illustrate the findings of the paper