An analytic method for measuring accurate fundamental frequency components

• Published in: IEEE transactions on power delivery Vol. 17; no. 2; pp. 405 - 411
• Main Authors: Nam, Soon-Ryul, Kang, Sang-Hee, Park, Jong-Keun
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2002; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Distortion; Distortion measurement; Electromagnetic measurements; EMTP; Fault currents; Fault location; Faults; Frequency estimation; Frequency measurement; Harmonics; Linear filters; Mathematical analysis; Nonlinear filters; Parameter estimation; Power harmonic filters; Prony's method; Resonant frequency; Sound; Transmission line measurements
• ISSN: 0885-8977; 1937-4208
• DOI: 10.1109/61.997907

This paper proposes an analytic method for measuring the accurate fundamental frequency component of a fault current signal distorted with a DC-offset, a characteristic frequency component, and harmonics. The proposed algorithm is composed of four stages: sine filter, linear filter, Prony's method, and measurement. The sine filter and the linear filter eliminate harmonics and the fundamental frequency component, respectively. Then Prony's method is used to estimate the parameters of the DC-offset and the characteristic frequency component. Finally, the fundamental frequency component is measured by compensating the sine-filtered signal with the estimated parameters. The performance evaluation of the proposed method is presented for a-phase to ground faults on a 345 kV 200 km overhead transmission line. The electromagnetic transient program (EMTP) is used to generate fault current signals under different fault locations and fault inception angles. It is shown that the analytic method accurately measures the fundamental frequency component regardless of the characteristic frequency component as well as the DC-offset.