Improving the Performance of Induction Motors for Agricultural Pumping Applications under Variable Supply Voltage: A Design Consideration

摘要

Induction motor performance deteriorates due to electrical and mechanical reasons. As supply voltage deviates from normal so does the performance in both the directions. Increased voltage results in increased magnetizing current and core losses, whereas, reduced voltage operation results in increased stator and rotor copper loss adversely affecting the performance in terms of temperature rise and efficiency. In the present context the voltage profile in most distribution networks is poor since the system operates with excessive reactive power demand. The paper describes a consideration in designing an induction motor, which gives desired/acceptable performance at different supply voltage even when operated without protection. The objective has been achieved by modifying the classical design of three-phase induction motor partly. In modified procedure main dimensions, as obtained using classical design procedure, are retained. Only number of turns in stator winding per phase are varied and optimum performance for varying supply voltage is evaluated and optimum number of turns for stator winding are retained. The developed algorithm is implemented on a 415 V, 10 hp, 4 Pole, three-phase squirrel cage induction motor.