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The effective harmonics estimation for measuring power signals has become an important issue in the power quality assessment. By reviewing those commonly used Kahnan filter-based models, some limitations for harmonics estimation can be observed. In this paper an extended real model of Kalman filter combined with a resetting mechanism for accurately tracking time-varying harmonic components of power signals is presented. The usefulness of the proposed algorithm is demonstrated by a simple laboratory setup with LabVIEW program and the dedicated hardware for harmonics monitoring. Results show that the proposed method can achieve more accurate and robust measurement of harmonic amplitudes and phase angles for the time-varying power signals among compared methods while the uncertainty testing performances required by LEC Standard 61000-4-30 are satisfied. [ABSTRACT FROM AUTHOR]

This letter proposes a curve-fitting approach for modeling fluorescent lamp voltage--current characteristics based on measured lamp voltage and current. The fluorescent lamp conductance is considered as a series of piecewise cubic polynomials that describes the nonlinear voltage--current characteristic of the lamp. The proposed model has been tested with a 10-W conventional 60-Hz fluorescent lamp and a 20-W high-frequency energy-saving lamp. By comparing the measured and simulated results, it shows that the proposed model can accurately model the lamps for harmonic studies. [ABSTRACT FROM AUTHOR]

This letter presents a new control strategy to determine the reference compensation voltages of a series active power filter (APF) operated under nonideal supply voltages in the steady-state. By employing the proposed control strategy, the load-side voltages can be maintained as being sinusoidal and balanced. The effectiveness of the proposed control strategy is demonstrated through simulations by the use of Pspice. Results show that the expected series APF performances are achieved. [ABSTRACT FROM AUTHOR]

This paper presents an efficient approach for tracking the location of the electric utility shunt capacitor bank that generates switching transients by a limited number of power quality (PQ) meters. The approach is based on measuring the voltage-disturbance energy variations at the meter buses and phase angle changes at the connected branch current due to the reactive power supplied by the switched-on utility capacitor. Both measured energy and phase angle variations are used to identify the location of the switched capacitor through a rule-based tracking algorithm. The proposed method is then tested with the IEEE 30-bus transmission system to show its usefulness. [ABSTRACT FROM AUTHOR]