Engineering Commons^™

Comparative Study Of Winding Configurations Of A Five-Phase Flux-Switching Pm Machine, Hao Chen, Xiangdong Liu, Ayman M. El-Refaie, Jing Zhao, Nabeel Demerdash, Jiangbiao He

Electrical and Computer Engineering Faculty Research and Publications

This paper introduces a general method for determination of the most suitable winding configurations for five-phase flux-switching permanent magnet (FSPM) machines, associated with feasible stator/rotor-pole combinations. Consequently, the effect of winding configurations on the performance of a five-phase outer-rotor FSPM machine is thoroughly investigated, including non-overlapping concentrated windings (single-layer, double-layer, and multi-layer) as well as distributed winding. The electromagnetic characteristics in the low-speed region, the flux-weakening capability in the high-speed region, and the fault-tolerant capability under faulty situations are evaluated and compared in detail. This work shows that compared with the conventional single-layer or double-layer concentrated windings, the FSPM machine …

Toward A Sustainable More Electrified Future: The Role Of Electrical Machines And Drives, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

This article provided an overview of the broad range of applications in which advanced electrical machines and drives play a key role. There are many applications that require steep change in the performance of electrical machines and drives. In addition to novel topologies and design optimization, a broad range of enabling technologies, including advanced materials and thermal management, will play a key role in meeting the ever-growing requirements of the aforementioned applications. Judging by the breadth of the applications and the very demanding requirements in terms of system footprint, efficiency cost, and reliability R&D efforts in the area of advanced …

Optimal Design Of Ipm Motors With Different Cooling Systems And Winding Configurations, Alireza Fatemi, Dan M. Ionel, Nabeel Demerdash, Thomas W. Nehl

Electrical and Computer Engineering Faculty Research and Publications

Performance improvement of permanent magnet (PM) motors through optimization techniques has been widely investigated in the literature. Oftentimes the practice of design optimization leads to derivation/interpretation of optimal scaling rules of PM motors for a particular loading condition. This paper demonstrates how these derivations vary with respect to the machine ampere loading and ferrous core saturation level. A parallel sensitivity analysis using a second-order response surface methodology followed by a large-scale design optimization based on evolutionary algorithms are pursued in order to establish the variation of the relationships between the main design parameters and the performance characteristics with respect to …

Calculation Of Magnet Losses In Concentrated-Winding Permanent-Magnet Synchronous Machines Using A Computationally Efficient Finite-Element Method, Peng Zhang, Gennadi Y. Sizov, Jiangbiao He, Dan M. Ionel, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

The proposed hybrid method combines computationally efficient finite-element analysis (CE-FEA) with a new analytical formulation for eddy-current losses in the permanent magnets (PMs) of sine-wave current-regulated brushless synchronous motors. The CE-FEA only employs a reduced set of magnetostatic solutions yielding substantial reductions in the computational time, as compared with the conventional FEA. The 3-D end effects and the effect of pulsewidth-modulation switching harmonics are incorporated in the analytical calculations. The algorithms are applied to two fractional-slot concentrated-winding interior PM motors with different circumferential and axial PM block segmentation arrangements. The method is validated against 2-D and 3-D time-stepping FEA.

Modeling And Parametric Design Of Permanent-Magnet Ac Machines Using Computationally Efficient Finite-Element Analysis, Gennadi Y. Sizov, Dan M. Ionel, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

Computationally efficient finite-element analysis (FEA) (CE-FEA) fully exploits the symmetries of electric and magnetic circuits of sine-wave current-regulated synchronous machines and yields substantial savings of computational efforts. Motor performance is evaluated through Fourier analysis and a minimum number of magnetostatic solutions. The major steady-state performance indices (average torque, ripple and cogging torque, back-electromotive-force waveforms, and core losses) are satisfactorily estimated as compared with the results of detailed time-stepping (transient) FEA. In this paper, the CE-FEA method is presented and applied to a parametric design study for an interior-permanent-magnet machine. Significant reduction of simulation times is achieved (approximately two orders of …

Analysis And Diagnostics Of Adjacent And Nonadjacent Broken-Rotor-Bar Faults In Squirrel-Cage Induction Machines, Gennadi Y. Sizov, Ahmed Mohamed Sayed Ahmed, Chia-Chou Yeh, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

In this paper, faults associated with the rotor of an induction machine are considered. More specifically, effects of adjacent and nonadjacent bar breakages on rotor fault diagnostics in squirrel-cage induction machines are studied. It is shown that some nonadjacent bar breakages may result in the masking of the commonly used fault indices and, hence, may lead to a possible misdiagnosis of the machine. A discussion of the possible scenarios of these breakages as well as some conclusions regarding the types of squirrel-cage induction machines (number of poles, number of squirrel-cage bars, etc.) that may be more prone to these nonadjacent …

A Reconfigurable Motor For Experimental Emulation Of Stator Winding Inter-Turn And Broken Bar Faults In Polyphase Induction Machines (Journal Article), Chia-Chou Yeh, Gennadi Y. Sizov, Ahmed Sayed-Ahmed, Nabeel Demerdash, Richard J. Povinelli, Edwin E. Yaz, Dan M. Ionel

Electrical and Computer Engineering Faculty Research and Publications

The benefits and drawbacks of a 5-hp reconfigurable induction motor, which was designed for experimental emulation of stator winding interturn and broken rotor bar faults, are presented in this paper. It was perceived that this motor had the potential of quick and easy reconfiguration to produce the desired stator and rotor faults in a variety of different fault combinations. Hence, this motor was anticipated to make a useful test bed for evaluation of the efficacy of existing and new motor fault diagnostics techniques and not the study of insulation failure mechanisms. Accordingly, it was anticipated that this reconfigurable motor would …

On Innovative Methods Of Induction Motor Interturn And Broken-Bar Fault Diagnostics, Behrooz Mirafzal, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

A fault indicator, the so-called swing angle, for broken-bar and interturn faults is investigated in this paper. This fault indicator is based on the rotating magnetic-field pendulous-oscillation concept in faulty squirrel-cage induction motors. Using the "swing-angle indicator," it will be demonstrated here that an interturn fault can be detected even in the presence of machine manufacturing imperfections. Meanwhile, a broken-bar fault can be detected under both direct-line and PWM excitations, even under the more difficult condition of partial-load levels. These two conditions of partial load and motor manufacturing imperfections, which are considered as difficult situations for fault detection, are investigated …

Effects Of Load Magnitude On Diagnosing Broken Bar Faults In Induction Motors Using The Pendulous Oscillation Of The Rotor Magnetic Field Orientation, Behrooz Mirafzal, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

The effects of load level on the ability to diagnose broken bar faults in squirrel-cage induction motors are studied in this paper. The pendulous oscillation of the rotor magnetic field orientation is implemented as a fault signature for rotor fault diagnostic purposes at steady-state operations. Moreover, the effects of load level on the low-side band component of the stator current spectrum, and associated diagnostic difficulties in this approach particularly in the presence of motor operation from pulsewidth-modulation drives, are reported as well. These investigations were performed through testing 2-hp and 5-hp induction motors over a wide range of load levels …

Condition Monitoring Of Squirrel-Cage Induction Motors Fed By Pwm-Based Drives Using A Parameter Estimation Approach, Behrooz Mirafzal, F. Fateh, Chia-Chou Yeh, Richard J. Povinelli, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

Abstract:

A rotor condition monitoring technique is presented in this paper based on a parameter estimation approach. In this technique, the stator currents, voltages and motor speed are used as the input signals, where the outputs will be the rotor's inductance, resistance and consequently rotor time constant. This approach is verified by simulation of two different induction motor cases. These simulations are buttressed by experimental data obtained for a 2-hp induction motor in the case of healthy as well as one, three and five rotor bar breakages. In these tests, the induction motor was energized from a PWM-based drive, in …

Induction Machine Broken-Bar Fault Diagnosis Using The Rotor Magnetic Field Space-Vector Orientation, Behrooz Mirafzal, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

A new technique based on rotor magnetic field space vector orientation is presented to diagnose broken-bar faults in induction machines operating at steady state. In this technique, stator currents and voltages are used as inputs to compute and subsequently observe the rotor magnetic field orientation, which has a more significant "swing-like" pendulous oscillation in case of broken-bar faults than in healthy operation. It will be shown here that the range of this "pendulous oscillation" is a function of the number of broken bars. Also in this technique, it was found that an inter-turn shorted stator-winding fault, which exhibits similar pendulous …