Comparative analysis of the three- and six-phase fractional slot concentrated winding permanent magnet machines

2017 ◽  
Vol 36 (3) ◽  
pp. 811-823 ◽  
Author(s):  
Cezary Jedryczka
Keyword(s):  
Permanent Magnet ◽  
Computer Code ◽  
Radial Component ◽  
Radial Force ◽  
Test Machine ◽  
Magnetomotive Force ◽  
Content Type ◽  
Three Phase ◽  
Torque Ripples ◽  
Fractional Slot

Purpose The purpose of this paper is to analyse and compare the functional parameters of three- and six-phase permanent magnet synchronous motors (PMSM) with fractional-slot concentrated windings (FSCW). Design/methodology/approach The investigations are focused on the comparison of the distortions of back electromotive force (emf) and magnetomotive force (mmf) waveforms, as well as torque ripples, radial force spatial harmonics and motor performance studies. The finite element models of the test machine and a personally developed computer code have been used to calculate motor characteristics and analyse and synthesise multiphase winding layouts, respectively. Findings Compared with the traditional three-phase PMSM designs, the proposed six-phase machines are characterized by a significantly lower content of sub-harmonics in mmf waveform distribution. Moreover, the investigated six-phase machines exhibited a higher average value of electromagnetic torque, significantly lower torque ripples and a reduced value of low-order harmonics of the radial component of the electromagnetic force in the air-gap of the machine. Originality/value The analyses presented in this paper show that six-phase PMSM with FSCWs are advantageous to their counterpart three-phase machines. Specifically, they are more suited to working with multiple drives supplying a segmented winding system while simultaneously offering higher performance. This suitability to the use of a multi-drive supply for one motor offers flexibility and cost reduction while increasing the fault tolerance of a power train system.

Multiphase permanent magnet synchronous motors with fractional slot windings

2016 ◽  
Vol 35 (6) ◽  
pp. 1937-1948 ◽  
Author(s):  
Cezary Jedryczka ◽  
Wojciech Szelag ◽  
Zbigniew Jerry Piech
Keyword(s):  
Permanent Magnet ◽  
Fault Tolerant ◽  
Computer Code ◽  
Permanent Magnet Synchronous Motors ◽  
Magnetomotive Force ◽  
Content Type ◽  
Synchronous Motors ◽  
Three Phase ◽  
Torque Pulsations ◽  
Fractional Slot

Purpose The purpose of this paper is to investigate advantages of multiphase permanent magnet synchronous motors (PMSM) with fractional slot concentrated windings (FSCW). The investigation is based on comparative analysis and assessment of FSCW PMSM wound as 3, 6, 9 and 12 phase machines suited for low speed applications. Design/methodology/approach The investigations are focussed on distortions of back electromotive (emf) and magnetomotive force (mmf) with the torque ripples and motors’ performance taken into account. The finite element models with the aid of customized computer code have been adopted for motor winding design and back emf, mmf and motor performance analyses. Findings The novel multiphase winding layouts were found to offer lower content of sub-harmonics in the mmf waveforms compared with the traditional three-phase machine designs. Moreover, the investigated multiphase machines exhibited higher average value of the electromagnetic torque, while the multiphase PMSM machines with FSCW were further characterized by significantly lower torque pulsations. Originality/value The analyses presented in this paper demonstrate that PMSM with FSCW are advantageous to their counterpart three-phase machines. Specifically, they offer higher performance and are more suitable to work with multiple drives supplying segmented winding system. This ability of using multi-drive supply for one motor offers flexibility and cost reduction while increasing fault tolerant power train system.

Decomposition of the compromise objective function in the permanent magnet synchronous motor optimization

2015 ◽  
Vol 34 (2) ◽  
pp. 496-504 ◽  
Author(s):  
Lech Nowak ◽  
Łukasz Knypiński ◽  
Cezary Jedryczka ◽  
Krzysztof Kowalski
Keyword(s):  
Objective Function ◽  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Computer Code ◽  
Synchronous Motor ◽  
Optimization Process ◽  
Field Equations ◽  
Cogging Torque ◽  
Content Type ◽  
Shaft Torque

Purpose – The purpose of this paper is to elaborate an algorithm and the computer code for the optimization of the permanent magnet synchronous motor (PMSM) including the shaft torque, the cogging torque, the total harmonic distortion factor of the back EMF and magnet volume into compromise objective function. Design/methodology/approach – The mathematical model of the device includes the magnetic field equations with the nonlinearity of the magnetic core taken into account. The numerical implementation is based on the finite element method (FEM) and time stepping procedure. The genetic algorithm has been applied for the optimization. The comprehensive computer code containing the FEM model and optimization procedures have been elaborated. Findings – Very important problem at formulating the optimization task is the choice of the functional parameters which constitute the objective and constraint functions. In the paper it has been shown that uncritical constructing the objective function could lead to irrational variants of the designed object. Authors pointed out (Knypiński et al., 2013) that connecting the shaft torque and the cogging torque simultaneously into the one compromise objective function generates ineffective operation of the optimization algorithm and often also leads to the non-optimal result. Originality/value – Authors proved that in case of multi-criterion objective function composed of terms which have very different impact on this function value (i.e. very diverse sensitivity of the objective function for these terms is observed) than the optimization process can be significantly distorted. Therefore, decomposition of the optimization process into two stages has been proposed. Some of the parameters (e.g. cogging torque) have been excluded from the first stage of the process. The two stage algorithm has been successfully implemented and tested on the example of PMSM machine.

scholarly journals Fault-Tolerant Control of a Three-Phase Permanent Magnet Synchronous Motor for Lightweight UAV Propellers via Central Point Drive

Actuators ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 253
Author(s):  
Aleksander Suti ◽  
Gianpietro Di Rito ◽  
Roberto Galatolo
Keyword(s):  
Permanent Magnet ◽  
Fault Tolerant ◽  
Permanent Magnet Synchronous Motor ◽  
Fault Tolerant Control ◽  
Synchronous Motor ◽  
Central Point ◽  
Fault System ◽  
Three Phase ◽  
Electrical Faults ◽  
Torque Ripples

This paper deals with the development and the performance characterization of a novel Fault-Tolerant Control (FTC) aiming to the diagnosis and accommodation of electrical faults in a three-phase Permanent Magnet Synchronous Motor (PMSM) employed for the propulsion of a modern lightweight fixed-wing UAV. To implement the fault-tolerant capabilities, a four-leg inverter is used to drive the reference PMSM, so that a system reconfiguration can be applied in case of a motor phase fault or an inverter fault, by enabling the control of the central point of the three-phase connection. A crucial design point is to develop Fault-Detection and Isolation (FDI) algorithms capable of minimizing the system failure transients, which are typically characterized by high-amplitude high-frequency torque ripples. The proposed FTC is composed of two sections: in the first, a deterministic model-based FDI algorithm is used, based the evaluation of the current phasor trajectory in the Clarke’s plane; in the second, a novel technique for fault accommodation is implemented by applying a reference frame transformation to post-fault commands. The FTC effectiveness is assessed via detailed nonlinear simulation (including sensors errors, digital signal processing, mechanical transmission compliance, propeller loads and electrical faults model), by characterizing the FDI latency and the post-fault system performances when open circuit faults are injected. Compared with reports in the literature, the proposed FTC demonstrates relevant potentialities: the FDI section of the algorithm provides the smallest ratio between latency and monitoring samples per electrical period, while the accommodation section succeeds in both eliminating post-fault torque ripples and maintaining the mechanical power output with negligible efficiency degradation.

A deterministic semi-infinite global optimization method to design slotless permanent magnet machines

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zahia Amrouchi ◽  
Frederic Messine ◽  
Clement Nadal ◽  
Mohand Ouanes
Keyword(s):  
Global Optimization ◽  
Permanent Magnet ◽  
Analytical Model ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Angular Position ◽  
Torque Ripple ◽  
Deterministic Global Optimization ◽  
Content Type ◽  
Torque Ripples

Purpose In this work, a method to design a slotless permanent magnet machine (SPMM) based on the joint use of an analytical model and deterministic global optimization algorithms is addressed. The purpose of this study is to propose to include torque ripples as an extra constraint in the optimization phase involving de facto the study of a semi-infinite optimization problem. Design/methodology/approach Based on the use of a well-known analytical model describing the electromagnetic behavior of an SPMM, this analytical model has been supplemented by the calculus of the dynamic torque and its ripples to carry out a more accurate optimized sizing method of such an electromechanical converter. As a consequence, the calculated torque depends on a continuous variable, namely, the rotor angular position, resulting in the definition of a semi-infinite optimization problem. The way to solve this kind of semi-infinite problem by discretizing the rotor angular position by using a deterministic global optimization solver, that is to say COUENNE, via the AMPL modeling language is addressed. Findings In this study, the proposed approach is validated on some numerical tests based on the minimization of the magnet volume. Efficient global optimal solutions with torque ripples about 5% (instead of 30%) can be so obtained. Research limitations/implications The analytical model does not use results from the solution of two-dimensional field equations. A strong assumption is put forward to approximate the distribution of the magnetic flux density in the air gap of the SPMM. Originality/value The problem to design an SPMM can be efficiently formulated as a semi-infinite global optimization problem. This kind of optimization problems are hard to solve because they involve an infinity of constraints (coming from a constraint on the torque ripple). The authors show in this paper that by using analytical models, a discretization method and a deterministic global optimization code COUENNE, this problem is efficiently tackled. Some numerical results show that the deterministic global solution of the design can be reached even if the step of discretization is small.

The influence of inter-turn short circuit fault considering loop current on the electromagnetic field of permanent magnet synchronous motor

2017 ◽  
Vol 36 (4) ◽  
pp. 1028-1042 ◽  
Author(s):  
Hongbo Qiu ◽  
Wenfei Yu ◽  
Shuai Yuan ◽  
Bingxia Tang ◽  
Cunxiang Yang
Keyword(s):  
Electromagnetic Field ◽  
Permanent Magnet ◽  
Short Circuit ◽  
Phase Lag ◽  
Field Calculation ◽  
Loop Current ◽  
Content Type ◽  
Phase Current ◽  
Three Phase ◽  
The Impact

Purpose The impact of the loop current (LC) on the motor magnetic field in the analysis of the inter-turn short circuit (ITSC) fault is always ignored. This paper made a comparative study on the electromagnetic field of permanent magnet synchronous motors (PMSM). The purpose of this study is to explore the necessary of the LC existing in the fault analysis and the electromagnetic characteristics of the PMSM with the ITSC fault when taking into account the LC. Design/methodology/approach Based on the finite element method (FEM), the fault model was established, and the magnetic density of the fault condition was analyzed. The induced electromotive force (EMF) and the LC of the short circuit ring were studied. The three-phase induced EMF and the unbalance of the three-phase current under the fault condition were studied. Finally, a prototype test platform was built to obtain the data of the fault. Findings The influence of the fault on the magnetic density was obtained. The current phase lag when the ITSC fault occurs causes the magnetic enhancement of the armature reaction. The mechanism that LC hinders the flux change was revealed. The influence of the fault on the three-phase-induced EMF symmetry, the three-phase current balance and the loss was obtained. Originality/value The value of the LC in the short circuit ring and the influence of it on the motor electromagnetic field were obtained. On the basis of the electromagnetic field calculation model, the sensitivity of the LC to the magnetic density, induced EMF, current and loss were analyzed.

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