The complex rotor structure of the synchronous reluctance machine (SynRM ) is analyzed in this paper. Three macroscopic design parameters are introduced: insulation ratios in the d- and q -axes and the rotor slot pitch in the d-axis controller angle. These parameters are optimally linked to the microscopic and detailed SynRM rotor geometry (barriers, insulation layer and segments, magnetic layers inside the rotor) parameters (dimensions) by introducing and combining a general rotor arrangement with an analytical explanatory theory. This theory represents the anisotropic behavior of the SynRM rotor structure according to the literature. Based on these parameters, a novel, simple, fast, and systematic design procedure for a SynRM rotor with specific stator structure is developed and presented. A SynRM rotor can be competitively optimized with respect to an induction machine (IM) by a limited number of finite-element-method sensitivity analysis studies of the macroscopic design parameters. The machine torque can be maximized by finding the best insulation ratios, while the torque ripple can be minimized by determining the best rotor slot pitch in the d-axis. Both these optimizations can be defined independently of the stator structure. The method is validated by the design (using this procedure), prototype, and measurement of a specific SynRM machine with three barriers and a stator standard frame size of 160 [International Electrotechnical Commission (IEC)]. A heat-run test was done for both the SynRM and its corresponding IM with the same stator and test bench.

Novel High-Performance SynRM Design Method: An Easy Approach for A Complicated Rotor Topology

The modern synchronous reluctance motor drive is illustrated as a new incoming technology solution. High anisotropy motor design is briefly summarized. The obtainable performance in terms of torque-per-volume is then compared to that of brushless and induction motors. With reference to traditional vector current control, the peculiarities of the synchronous reluctance motor drive are shown. Moreover, the effect of some second-order control aspects are evidenced, together with the possible advantages of adoption of flux-observer based schemes. Finally, both research and industrial trends in this field are summarized. >

The synchronous reluctance solution: a new alternative in AC drives

The synchronous reluctance solution: a new alternative in A.C. drives

The aim of this paper is to investigate and compare the torque behavior of induction motors and transverse laminated synchronous reluctance motors. Each induction motor is compared with a synchronous reluctance motor, that has the same stator lamination and winding but, obviously, different rotor. The thermal analysis has been based on a fully experimental approach and the results have shown that the synchronous reluctance motor can give from 10% to 25% more torque than the corresponding induction motor, depending on motor size and importance of I.M. rotor losses. The torque comparison of the two motor types has been made at equal, measured winding temperature. In addition, the difference in power factor and efficiency is also pointed out.

Experimental comparison of induction and synchronous reluctance motors performance

This thesis is comprehensively dedicated to the theoretical and experimental reevaluation of the Synchronous Reluctance Machine (SynRM). A simple approach to derive the SynRM main characteristics and behavior is followed. An introduction to an evaluation of the different control strategies in is given. Finding suitable rotor geometry for the SynRM has been a subject for major investigation since 1923. This thesis will investigate the interior barrier rotor structure of the SynRM using the Finite Element Method (FEM) based sensitivity analysis. The Permanent Magnet assisted SynRM (PMaSynRM) is studied. The main aim here is to address accurately, qualitatively and quantitatively the main characteristics of such a machine. A heat-run test has been done on a prototyped SynRM and its corresponding IM and Interior Permanent Magnet (IPM) Machine to investigate the potential of the SynRM, under variable speed drive (VSD) supply conditions. This gives the state-ofart based on these measurements on the prototype SynRM and benchmarks its performance. The main behavior and characteristics of an anisotropic structure, suitable for high performance SynRM rotor geometry design, is distinguished and discussed. The carefully selected general rotor shape and some optimum distribution rules are used to develop a novel FEM-aided fast rotor design optimization for SynRM. Torque ripple minimization of SynRM is discussed. This is done by the development of a general method that minimizes the ripple independent of the stator structure. The torque ripple and interconnection to iron losses are briefly discussed. Based on these design tools, a design that is a compromise between the final machine?s performance and simplicity of the rotor structure is studied as the improved machine design. The fine tuned most promising design is prototyped and its performance compared with IM. Naturally, to have an anisotropic structure the q-axis flux must be blocked and simultaneously the d-axis flux must flow smoothly. One possibility is to align the barrier edges along the d-axis natural flux lines in the solid rotor. A prototype of the final optimized machine design SynRM is manufactured. The performance of this machine is measured and compared with the improved machine design. The effect of the number of poles on SynRM performance is discussed. Some of the most important secondary effects in SynRM are studied. Skew and torque quality, the possible effects of alternative voltage or current source supplies on torque and iron losses, the start-up and short-circuit locked rotor tests performed on the standard IM and the prototype SynRM and the effect of eccentricity are investigated. An overview comparison between IM and SynRM is given. For this purpose, a high performance rotor structure for SynRM with standard sizes of 3kW, 15kW and 90kW is designed. The thermal performance of the SynRM is discussed by analyzing the measured machine temperatures. A detailed picture regarding the thermal performance of the SynRM machine is presented. A full scale performance evaluation of the SynRM in comparison to its counterpart the IM is given. All IM and SynRM motors have the same standard stator for each size. The MTPA control strategy is used. Finally, all reported measurements in this thesis are summarized and analyzed.

C. Petrache

Papers

Design comparison between induction and synchronous reluctance motors

Control of high performance synchronous reluctance drives