A comparative performance analysis of induction and synchronous reluctant motors in an adjustable-speed electric drive

Resumo

This article is concerned with comparative analysis of the energy performance of induction motors (IM) and synchronous reluctance motors (SynRM) in an adjustable electric drive. A feasibility study of an economically viable adjustable electric drive with a SynRM of improved design that is free from electric losses in rotor winding and corresponds to the highest energy-efficiency classes (IE3 and IE4 according to GOST (State Standard) R 54413-2011) is carried out. Results of the comparative analysis of operating and power characteristics of the IM and SynRM with the same stator design are presented in respect to pumps using various principles of control. It is shown that the advantage in the SynRM efficiency is achieved to the fullest extent when the electric angle between the current vector and the axis of the maximum rotor magnetic conductivity is constant. The calculations are performed on the basis of the ac-motor equivalent circuit. A calculation of equivalent circuit parameters for motors of a certain power is performed on the basis of nominal data on the IM being considered. At the same time, the SynRM parameters are calculated from the ratio of inductance parameters for a particular rotor design according to the literature. It is concluded that the SynRM efficiency can be significantly higher than that of the IM of the same power in the entire range of electric-drive speed regulation.