Estimating power factor of induction motors using regression technique

Abstract

Induction motors are one of the largest power consumption in electrical systems. Since induction motors are inductive loads, they produce a lot of power quality issue in the electrical systems. Solving the power quality problem, monitoring power factor of induction motors is important because at no load or light load condition power factor is low and consequently low power factor not only provide a penalty charge, but also generates a huge current and losses in the grid systems. To measure the power factor, zero crossing and instantaneous power methods can be used. Both methods require motor voltage and current waveforms at operating times. Those methods may have a huge cost in terms of requiring the motor to be out of service for connecting devices. In this research, regression analysis will be applied to estimate the power factor of induction motor at any loading condition. The results of the proposed method will be compared with the measured power factor of induction motor in order to substantiate the feasibility of the proposed method.