Power System Frequency Estimation using Teager Energy operator

Abstract

Under unbalanced and harmonic conditions, this paper proposes a fundamental frequency estimation technique for three-phase voltage systems. And the technique is based on the Clark transformation, recursive discrete Fourier transform, and Teager energy operator, it is computationally effective and relatively easy to implement, making it perfect for low-cost applications. It does not require real-time estimation of the computationally challenging inverse trigonometric function. The proposed approach has no aggregation error and it is not affected even though the signal is sampled at zero or close to zero. It takes settling time less than 15ms (i.e. 75% of the one fundamental time period) for estimating the fundamental frequency step range of ±7.5Hz from the nominal value. Hence it produces a fast response under dynamic conditions. Simulation is used to verify the technique's performance.