A Novel Equivalent Circuit for Induction Motors under Voltage Fluctuation Conditions

Voltage fluctuation is one of the important types of power quality aspects originated from heavy fluctuating loads. This phenomenon can influence the behavior of induction motors, produce excessive vibration and increase the ohmic losses. In this paper a simplified model to evaluate the electrical characteristics of three phase induction motors under voltage fluctuation conditions will be presented and verified using small and large signal analysis. The model consisting of two equivalent circuits gives the total current and torque perturbations and additional loss increase when induction motors are subjected to regular sinusoidal voltage fluctuations. Furthermore, the dependency of the electrical characteristics of induction motors on the frequency and depth of voltage Fluctuations is also examined.