Mihail E. Popescu

Learn More
The possibility of obtaining lower space harmonic content for the fractional-slot, tooth-concentrated windings by multiplying the number of coils, leading to bigger number of layers in the armature slots is presented. By using multiple layer windings it is possible to reduce or even to cancel some space sub-harmonics having as final result lower eddy(More)
In this paper, a complete theory and analysis method for combined star-delta three-phase windings from the point of view of magnetomotive force spatial harmonics content and equivalent winding factors calculation is developed. The method allows for any spatial angle and any coils percentage distribution between star and delta balanced winding systems. It is(More)
The paper is evaluating the main performances of the low speed, multi-pole permanent magnet synchronous generator provided with fractional, tooth concentrated windings. The constructive aspects versus running characteristics as cogging torque and full load/no-load voltage are presented for surface mounted permanent magnets generators. Appreciations are made(More)
Partial-parallel-path-winding starting of three-phase induction motors is used in order to reduce the starting currents in hard-load condition, as it is the case of special compressors application. In the paper, two possibilities of winding arrangement are analysed from the point of view of air gap field, taking into account the upper space harmonics of the(More)
This paper deals with several methods for the reduction of cogging torque in case of low speed permanent magnets wind generators. The first analyzed method consists in asymmetrical spacing of the permanent magnets on the rotor outer surface. The second method consists in using close stator slots that determines a nearly isotropic magnetic stator structure.(More)
This paper deals with the finite element estimation of cogging torque oscillations that occur in multipole permanent magnets synchronous wind generators. The numerical analysis is carried out using a 2D plane-parallel finite element model of the machine and afterward a more elaborated 3D model able to take into account the skewing of the stator slots. The(More)
A new concept of three phase synchronous motor with permanent magnets and additional squirrel cage in the rotor is presented from both manufacturing and experimental point of view. The permanent magnets have ring shape with axially magnetization and are imbedded in the claw pole ferromagnetic modular pieces. The main characteristics of the manufactured(More)
This paper presents a comparison between several numerical and analytical methods used to evaluate the End-Winding Inductance (EWI) of three phase stator windings of induction or synchronous machines. A prototype of a Permanent Magnet Synchronous Machine (PMSM) is considered as a case study for the illustration of the computational and experimental(More)
Contemporary superconductor synchronous motors utilize high current density, high temperature superconductor (HTS) direct current windings that request special cooling technologies. This paper presents a preliminary study in the design phase on several aspects of the thermal stability of a small power prototype of an HTS motor. The model we developed is(More)
The paper presents the achievements of INCDIE ICPE-CA in the field of permanent magnets electric generators, having both rotating armatures, developed for wind energy conversion with systems of counter rotating turbines. The innovative design of these generators has aimed to obtain an increased speed and eliminate the speed multiplier, which introduces(More)