Adaptive Estimation of Three-Phase Grid Voltage Parameters Under Unbalanced Faults and Harmonic Disturbances

• Published in: IEEE transactions on power electronics Vol. 32; no. 7; pp. 5613 - 5627
• Main Authors: Dai, Zhiyong, Lin, Wei
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive observer method; Amplitudes; asymptotic estimation; Computer simulation; Disturbances; Dynamic models; Electric potential; Frequency estimation; Harmonic analysis; harmonic disturbances; Observers; Parameter estimation; parameterized dynamic model; Phase locked loops; Power system harmonics; Steady-state; three-phase grid voltage parameters; unbalanced faults
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2016.2605131

In this paper, we present an adaptive observer-based, closed-loop feedback method to estimate three-phase grid voltage parameters, including frequencies, amplitudes, and phase angles under grid unbalanced faults and harmonic voltage disturbances. We treat the three-phase grid voltage signal as a solution of a parameterized dynamic system involving the unknown parameters-the fundamental and harmonic frequencies. Based on the parameterized dynamic model thus obtained, an adaptive observer is then proposed for achieving asymptotic estimation of the three-phase grid voltage parameters, that is, estimations of frequencies, amplitudes, and phase angles with zero steady-state error. This conclusion is proved rigorously by means of the Lyapunov stability theory, passivity, and La Salle's invariance principle. Both numerical simulations via MATLAB and dSPACE-based experiments are conducted to demonstrate the effectiveness and performance of the proposed estimation scheme.