| Abstract: | This paper presents a new sensorless method the so-called harmonic impedance /admittance, for detecting speed of induction motors, which is based on the impedancemeasurement, harnonic analysis and digital signal processing. The method improves theperformance of conventional voltage-based and current-based techniques, because theimpedance or admittance harmonics is independent of input or output of motor system due to thesystem-inherent nature of impedance. It has been used successfolly in detecting the rotor speed ofthree-phase induction motors. A comparison between the proposed method and the conventionalcurrent-based method is also demonstrated |
