A total least squares enhanced smart DFT technique for frequency estimation of unbalanced three-phase power systems. (June 2021)

• Record Type: Journal Article
• Authors: Li, Zhe
• Is Part Of: International journal of electrical power & energy systems. Volume 128(2021)
• Publication Date: 2021-06
• Subjects: Frequency estimation -- Discrete Fourier transform (DFT) -- Unbalanced three-phase power systems -- Total least squares (TLS); Electrical engineering -- Periodicals; Electric power systems -- Periodicals; Électrotechnique -- Périodiques; Réseaux électriques (Énergie) -- Périodiques; Electric power systems; Electrical engineering; Periodicals; 621.3
• DOI: 10.1016/j.ijepes.2020.106722
• Languages: English
• ISSNs: 0142-0615

Abstract

Highlights: The recursive relationship between the fundamental components of two consecutive DFT bins introduced by the smart DFT scheme is proven to be applied in the context of unbalanced three-phase power systems. The modelling mismatch inherently overlooked in the CLS-SDFT method was rectified by the proposed TLS framework. The performance advantage of the proposed TLS-SDFT algorithm is verified over various power system conditions. Abstract: In this paper, a robust technique is proposed for the estimation of fundamental frequency in unbalanced three-phase power systems. This is achieved by firstly justifying the modelling mismatch inherently overlooked in the conventional complex-valued least squares enhanced smart discrete Fourier transform method, and then applying the total least squares framework to minimise the error vectors corresponding to both the independent and dependent consecutive voltage measurements and, eventually, to achieve higher immunity to both noise and harmonic pollution. Simulations on both synthetic and real-world noisy unbalanced power systems demonstrate the performance advantage of the proposed algorithm over other smart discrete Fourier transform based ones.