Methodology for estimating the influence of voltage harmonics on efficiency and power factor of three-phase induction motors

This paper presents a methodology for quantify both induction motor efficiency and its power factor under non-sinusoidal conditions. The methodology uses an induction motor equivalent electric circuit, whose equations are solved with simulation using MATLAB and applying superposition principle to calculate its operation with harmonic frequencies. The methodology is applied on a 3 HP induction motor whose circuit parameters are determined experimentally. Results show that power factor does not vary with the harmonic distortion, while efficiency decreases when harmonic order increases.