Instantaneous Frequency Estimation in Unbalanced Systems Using Affine Differential Geometry

Abstract

The paper discusses the relationships between electrical and affine differential geometry quantities, establishing a link between frequency and time derivatives of voltage, through the utilization of affine geometric invariants. Based on this link, a new instantaneous frequency estimation formula is proposed, which is particularly suited for unbalanced and single-phase systems. Several examples as well as measurements based on two real-world events illustrate the findings of the paper.

Figures (5)

• Figure 1: Balanced 3-phase voltage components.
• Figure 2: Unbalanced 3-phase voltages and estimated frequencies.
• Figure 3: Estimated angular frequency.
• Figure 4: Estimated frequency, real voltage dip data from 690 V DFIG.
• Figure 5: Estimated angular frequency.