High-Speed Megawatt-Scale Induction-Motor Drives: Efficiency Maps and Drivetrains

Abstract

Selection of a proper drivetrain for a certain application is an important and challenging task. To make the right choice, several factors must be considered. The performance of an electrical drive system is among the crucial factors responsible for decision making. Although the performance at rated speed and torque is usually given, to estimate the losses under various operating scenarios it is necessary to know the efficiency values at different possible combinations of torque and speed. The paper focuses on megawatt-power range applications, where high-speed rotation is required. Efficiency maps showing the efficiency as a function of load torque and rotational speed are determined for the drivetrains with a gearbox and direct drive, as well as for their constituent parts. Presented results are intended to be useful for loss determining at a certain operating point, and for making a choice between different drivetrains.