Written Pole Motors – A few Aspects

Abstract
Electric motors are the main drives of today’s industries and consume nearly two third of total electric energy generated. The motors of capacity more than 10-15 hp range are needed for tiny commercial and agriculture loads. At present induction motors are widely deployed to meet these requirements but causes effect on the power quality and other connected loads. An attempt is made in this paper to reveal the performance of a written pole motor against that of induction motor. In written-pole technology the rotor field magnetic polarity changes. It is feasible even during the operation of the motor. Hence this technology provides flexibility to produce number of poles which has a correlation with the rotating speed of the motor. This enhances the performance of the motor throughout the operating speed range. Thus a constant frequency variable speed machine can be obtained by changing number of poles. Written-Pole motors manifest supreme starting characteristics, hence preferred to accelerate high inertia loads. It is inferential that two parameters stand out as important viz. improved efficiency and limited starting current when the written pole motors are compared with other motors.