Energy-Saving Electric Drives

Electric drive should meet the technological requirements at the lowest possible energy consumption. During design or modernisation of the drive, investment and operating costs must be balanced. The operating costs are dominated by the cost of energy consumed during the year. The largest energy savings are achieved by adjusting the rotational speed, this is exemplified by a belt conveyor drive. In addition, five variants of the 40 kW tram drive are presented in the paper, rated power and efficiency of different motors designed with identical dimensions are compared. DC series motor was used in trams manufactured in 20th century, but in new and modernized trams a squirrel cage induction motor with identical dimensions is used instead.