Kevin Lee

TL;DR: The simultaneous online estimation algorithm of rotor time constant and rotor speed for a speed-sensorless induction machine is proposed and the impact of stator resistance error is severely reduced by the closed-loop structure of combined voltage and current (UI) mode flux observer.

TL;DR: In this article, the effects of the input voltage unbalance and sags on the DC bus electrolytic capacitors in adjustable-speed drives (ASDs) were analyzed to predict their impact on expected capacitor lifetime.

TL;DR: In this paper, the authors proposed a method to automatically obtain the total output voltage delay curve, which is a significant part of the inverter voltage error model, in order to improve the performance of sensorless field-oriented controlled motor drives at low speed.

TL;DR: In this paper, the authors provided an approximate closed-form analysis of the impact of line-voltage sags and unbalance on the induction-machine phase voltages, currents, and torque pulsations for a general-purpose adjustable-speed drive (ASD) consisting of a three-phase diode bridge rectifier, a dc link, and a pulsewidth modulation (PWM) inverter delivering constant volts-per-hertz excitation.

TL;DR: In this article, the theoretical power spectrum analysis as the basis for random PWM in industrial and commercial adjustable-speed drives (ASD) is presented, and five state-of-the-art PWM strategies, their voltage, current, and acoustic noise spectra characteristics are quantitatively evaluated.