Reducing the Error in Phasor Estimates From Phasorlets in Fault Voltage and Current Signals

• Published in: IEEE transactions on instrumentation and measurement 2007-06, Vol.56 (3), p.856-866
• Main Author: de la O Serna, J. A
• Format: Article
• Language: English
• Subjects: Curve fitting; Delay estimation; digital filter; Digital filters; Electric potential; Equations; Errors; Estimates; Faults; Frequency estimation; Frequency response; least squares; Least squares approximation; Least squares method; Mathematical models; multirate estimation; nonorthogonal basis; normal equations; Numerical simulation; oblique planes; orthogonal decomposition; phasor estimation; phasorlets; Phasors; Signal analysis; Signal generators; signal projection; Voltage
• ISSN: 0018-9456; 1557-9662
• DOI: 10.1109/TIM.2007.894880

An assessment and reduction of the phasor-error infiltration in estimates from phasorlets are proposed in this paper through a generalized least-square formulation of the problem. It introduces a computationally simple and quick estimator that exploits the structure of the sinusoidal model and provides the finest stable phasor estimate, which is very useful for fault voltage signals. It also proposes an extended signal model, by including a dc component into the signal model, in order to allocate the phasor error, when an aperiodic component is present in the input signal. The numerical simulations illustrate the improvement in speed and accuracy of the estimates, which are obtained in decicycles, as well as its still wavering nature, which is considered as the persisting limitation of this technique