Sensorless Speed Control Methods for SynRM Drives Suitable for TractionApplications, An Overview

Electric motors are the most important part and one of the main consumers of traction applications.Choosing a suitable electric motor will have a significant impact on the efficiency and performanceof traction applications. In recent years, synchronous reluctance motor (SynRM) has become anattractive option and presents promising technology due to its remarkable features. Speed controland identification are one of the most important issues for SynRM. Conventionally, it is done bythe shaft encoder and mechanical sensors. However, using the speed control sensors causesmany problems and reduced the whole system reliability. Nowadays, the attention anddevelopment of sensorless speed control methods have increased and much of the researchis devoted to these methods. In the SynRM, the rotor position and speed are estimated usingmeasured stator voltages and currents. Therefore, based on accuracy, dependence onparameter variations of SynRM and required speed, various methods have been proposedfor sensorless speed control of the SynRM. This paper examines sensorless speed controlmethods to clarify which kind of these methods is more suitable for SynRM