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Article
Publication date: 12 August 2021

Wasiq Ullah, Faisal Khan, Muhammad Umair and Bakhtiar Khan

This paper aims to reviewed analytical methodologies, i.e. lumped parameter magnetic equivalent circuit (LPMEC), magnetic co-energy (MCE), Laplace equations (LE), Maxwell…

Abstract

Purpose

This paper aims to reviewed analytical methodologies, i.e. lumped parameter magnetic equivalent circuit (LPMEC), magnetic co-energy (MCE), Laplace equations (LE), Maxwell stress tensor (MST) method and sub-domain modelling for design of segmented PM(SPM) consequent pole flux switching machine (SPMCPFSM). Electric machines, especially flux switching machines (FSMs), are accurately modeled using numerical-based finite element analysis (FEA) tools; however, despite of expensive hardware setup, repeated iterative process, complex stator design and permanent magnet (PM) non-linear behavior increases computational time and complexity.

Design/methodology/approach

This paper reviews various alternate analytical methodologies for electromagnetic performance calculation. In above-mentioned analytical methodologies, no-load phase flux linkage is performed using LPMEC, magnetic co-energy for cogging torque, LE for magnetic flux density (MFD) components, i.e. radial and tangential and MST for instantaneous torque. Sub-domain model solves electromagnetic performance, i.e. MFD and torque behaviour.

Findings

The reviewed analytical methodologies are validated with globally accepted FEA using JMAG Commercial FEA Package v. 18.1 which shows good agreement with accuracy. In comparison of analytical methodologies, analysis reveals that sub-domain model not only get rid of multiples techniques for validation purpose but also provide better results by accounting influence of all machine parts which helps to reduce computational complexity, computational time and drive storage with overall accuracy of ∼99%. Furthermore, authors are confident to recommend sub-domain model for initial design stage of SPMCPFSM when higher accuracy and low computational cost are primal requirements.

Practical implications

The model is developed for high-speed brushless AC applications.

Originality/value

The SPMCPFSM enhances electromagnetic performance owing to segmented PMs configuration which makes it different than conventional designs. Moreover, developed analytical methodologies for SPMCPFSM reduce computational time compared with that of FEA.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 40 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 7 July 2020

Wasiq Ullah, Faisal Khan and Muhammad Umair

The purpose of this paper is to investigate an alternative simplified analytical approach for the design of electric machines. Numerical-based finite element method (FEM…

Abstract

Purpose

The purpose of this paper is to investigate an alternative simplified analytical approach for the design of electric machines. Numerical-based finite element method (FEM) is a powerful tool for accurate modelling and electromagnetic performance analysis of electric machines. However, computational complexity, magnetic saturation, complex stator structure and time consumption compel researchers to adopt alternate analytical model for initial design of electric machine especially flux switching machines (FSMs).

Design/methodology/approach

In this paper, simplified lumped parameter magnetic equivalent circuit (LPMEC) model is presented for newly developed segmented PM consequent pole flux switching machine (SPMCPFSM). LPMEC model accounts influence of all machine parts for quarter of machine which helps to reduce computational complexity, computational time and drive storage without affecting overall accuracy. Furthermore, inductance calculation is performed in the rotor and stator frame of reference for accurate estimation of the self-inductance, mutual inductance and dq-axis inductance profile using park transformation.

Findings

The developed LPMEC model is validated with corresponding FEA using JMAG Commercial FEA Package v. 18.1 which shows good agreement with accuracy of ∼98.23%, and park transformation precisely estimates the inductance profile in rotor and stator frame of reference.

Practical implications

The model is developed for high-speed brushless AC applications.

Originality/value

The proposed SPMCPFSM enhance electromagnetic performance owing to partitioned PMs configuration which make it different than conventional designs. Moreover, the developed LPMEC model reduces computational time by solving quarter of machine.

Article
Publication date: 7 March 2016

M. Zheng, Z.Z. Wu and Z.Q. Zhu

In this paper, the partitioned stator flux reversal permanent magnet (PM) (PS-FRPM) machines with Halbach array PMs are investigated to compare with the machine having the…

Abstract

Purpose

In this paper, the partitioned stator flux reversal permanent magnet (PM) (PS-FRPM) machines with Halbach array PMs are investigated to compare with the machine having the conventional parallel magnetized PMs, and conventional FRPM machine. This paper aims to discuss these issues.

Design/methodology/approach

The Halbach array PM machines with 2-, 3-, and 4-segment and ideal Halbach array PMs have similar topology and designed based on the PS-FRPM with parallel magnetized PMs. The open circuit analysis and electromagnetic performance has been calculated and compares with the aid of finite element (FE) method, and validated by experiments.

Findings

The PS-FRPMs with Halbach array PMs have higher back-EMF and torque performance, as well as lower cogging torque and torque ripple, all having significantly higher torque density than the FRPM machine with single stator. The experimental results and FE predicted results of the 2-segment Halbach PM prototype machine are compared and good agreement is achieved.

Originality/value

This paper introduces the new concept and design of PS-FRPMs having Halbach array PMs with different PM segments and idea PM array. The comparison with conventional FRPM and PS-FRPM with parallel magnetized PMs shows the benefits with PS-FRPMs with Halbach array PMs.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 7 March 2016

Yi Sui, Ping Zheng, Peilun Tang, Fan Wu and Pengfei Wang

The purpose of this paper is to investigate a five-phase permanent-magnet synchronous machine (PMSM) that features high-power density and high-fault-tolerant capability…

Abstract

Purpose

The purpose of this paper is to investigate a five-phase permanent-magnet synchronous machine (PMSM) that features high-power density and high-fault-tolerant capability for electric vehicles (EVs).

Design/methodology/approach

The five-phase 20-slot/18-pole PMSM is designed by finite-element method. Two typical rotor structures which include Halbach array and rotor eccentricity are compared to achieve sinusoidal back electromotive force (EMF). The influence of slot dimensions on leakage inductance and short-circuit current is analyzed. The method to reduce eddy current loss of permanent magnets (PMs) is investigated. The machine performances under both healthy and fault conditions are evaluated. Finally, thermal behavior of the machine is studied by Ansys.

Findings

With both no-load and load performances considered, rotor eccentricity is proposed to reduce the harmonic contents of EMF. Increasing slot leakage inductance is an effective way to limit the short-circuit current. By segmenting PMs in circumferential direction, the PM eddy current loss is reduced and the machine efficiency is improved. With proper fault-tolerant control strategy, acceptable torque performance can be achieved under fault conditions. The proposed machine can safely operate under Class F insulation.

Originality/value

So far, many researches focus on multiphase PMSMs used in aviation fields, such as fuel pump and electric actuator. Differing from PMSMs used in aviation applications, machines for EVs require characteristics like wide speed ranges and variable operating conditions. Hence, this paper proposes a five-phase 20-slot/18-pole PMSM for EVs. The proposed design methodology is applicable to multiphase PMSMs with different slot/pole combinations.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 4 September 2018

Lufeng Zhang and Kai Wang

The purpose of this paper is to investigate the electromagnetic performances of the permanent magnet linear synchronous machines (PMLSM) with sine and third harmonic (SIN…

Abstract

Purpose

The purpose of this paper is to investigate the electromagnetic performances of the permanent magnet linear synchronous machines (PMLSM) with sine and third harmonic (SIN + 3rd) shaping mover in comparison with the PMLSM with sine (SIN) shaping mover and conventional shaping mover.

Design/methodology/approach

The optimal amplitude of the injected third harmonic to re-shape the SIN + 3rd shaping permanent magnet (PM) for maximizing the thrust force is analytically derived and confirmed by finite element method (FEM). Furthermore, the PM edge thickness, the pole arc to pole pitch ratio and the tooth to slot ratio are optimized. It is found that the optimal amplitude of the injected third harmonic is one-sixth of the fundamental one, the optimal PM edge thickness, the pole arc to pole pitch ratio and the tooth to slot ratio are 0, 0.85 and 0.5 mm, respectively. In addition, the electromagnetic performances are analyzed and quantitatively compared for the PMLSM with SIN + 3rd shaping mover, SIN shaping mover and conventional shaping mover.

Findings

The average thrust force and efficiency of the PMLSM with SIN + 3rd shaping mover are improved significantly, while the thrust ripple is not increased, comparing to those of the PMLSM with SIN shaping mover. Meanwhile, the thrust ripple is lower than that of the conventional shaping mover.

Research limitations/implications

The purely sinusoidal currents are applied in this analysis and the influences of harmonics in the current on electromagnetic performances are not considered.

Originality/value

This paper presents a PMLSM with SIN + 3rd shaping mover to improve the thrust force and efficiency without increasing the thrust ripple, considering the effects of the amplitude of the injected third harmonic to re-shape the SIN + 3rd shaping PM, the PM edge thickness, the pole arc to pole pitch ratio and the tooth to slot ratio.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 7 November 2016

Lidija Petkovska, Goga Vladimir Cvetkovski and Paul Lefley

In the present paper the influence of the magnetization patterns of rotor magnets on the performance characteristics of a surface permanent magnet (SPM) motor has been…

Abstract

Purpose

In the present paper the influence of the magnetization patterns of rotor magnets on the performance characteristics of a surface permanent magnet (SPM) motor has been investigated. The purpose of this paper is to show how the electromagnetic and electromechanical characteristics of this type of motor can be significantly changed by applying various magnetization patterns of permanent magnets (PM) on the rotor surface.

Design/methodology/approach

First, a survey of possible and most frequently used magnetization patterns for PM motors is presented. The research is focussed on the comparison of performance characteristics and is developed at three levels. The study starts with investigation of a conventional SPM motor having segmented PM, and two magnetization patterns are considered: parallel and radial. As there was no significant difference in motor performance at parallel and radial magnetization, for further investigation only radial magnetization, being more conventional, was considered. In the second step, the counterparts of SPM with two Halbach array configurations, under the constraint of fixed magnet volume, are studied. Finally, detailed comparative analyses of SPM at radial, Halbach 1, and Halbach 2 magnetic patterns are presented. The advantages and drawbacks of the suggested magnetic configurations are then discussed.

Findings

The authors have shown how the magnetization pattern of rotor PM can have a substantial impact on the SPM motor performance characteristics. From the analysis of magnetic field properties at various types of magnetization, it is observed that both the shape and the rates of the characteristics, for radial magnetization and Halbach 2 configuration, exhibit similar features. This is because the Halbach 2 array cancels the magnetic flux above the PM – that is, it strengthens the magnetic field in the rotor, and enhances the coupling between the rotor and stator magnetic field. It is worth emphasizing that, because of less saturation of the magnetic core and lower iron loss at Halbach 1 and Halbach 2 magnetization, it is possible to increase the armature current and consequently increase the electromagnetic torque. This finding could be an interesting for further research.

Originality/value

The paper presents an original comparative analysis of the performance characteristics of a surface permanent motor at various magnetization patterns. The novelty of the paper is seen in the introduction of two Halbach magnetization arrays for PM and improvement of the performance characteristics of the analysed motor.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 35 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 December 2021

Heshan Zhang, YanPeng Wang, Jiying Tuo, Minglei Yang, Ying Ma and Jin Xu

This study aims to accurately calculate the magnetic field distribution, which is a prerequisite for pre-design and optimization of electromagnetic performance. Accurate…

Abstract

Purpose

This study aims to accurately calculate the magnetic field distribution, which is a prerequisite for pre-design and optimization of electromagnetic performance. Accurate calculation of magnetic field distribution is a prerequisite for pre-design and optimization.

Design/methodology/approach

This paper proposes an analytical model of permanent magnet machines with segmented Halbach array (SHA-PMMs) to predict the magnetic field distribution and electromagnetic performance. The field problem is divided into four subdomains, i.e. permanent magnet, air-gap, stator slot and slot opening. The Poisson’s equation or Laplace’s equation of magnetic vector potential for each subdomain is solved. The field’s solution is obtained by applying the boundary conditions. The electromagnetic performances, such as magnetic flux density, unbalanced magnetic force, cogging torque and electromagnetic torque, are analytically predicted. Then, the influence of design parameters on the torque is explored by using the analytical model.

Findings

The finite element analysis and prototype experiments verify the analytical model’s accuracy. Adjusting the design parameters, e.g. segments per pole and air-gap length, can effectively increase the electromagnetic torque and simultaneously reduce the torque ripple.

Originality/value

The main contribution of this paper is to develop an accurate magnetic field analytical model of the SHA-PMMs. It can precisely describe complex topology, e.g. arbitrary segmented Halbach array and semi-closed slots, etc., and can quickly predict the magnetic field distribution and electromagnetic performance simultaneously.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 41 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 2 January 2018

Behrooz Rezaeealam and Farhad Rezaee-Alam

The purpose of this paper is to present a new optimal design for integral slot permanent magnet synchronous motors (PMSMs) to shape the air-gap magnetic field in…

Abstract

Purpose

The purpose of this paper is to present a new optimal design for integral slot permanent magnet synchronous motors (PMSMs) to shape the air-gap magnetic field in sinusoidal and to reduce the cogging torque, simultaneously.

Design/methodology/approach

For obtaining this new optimal design, the influence of different magnetizations of permanent magnets (PMs), including radial, parallel and halbach magnetization is investigated on the performance of one typical PMSM by using the conformal mapping (CM) method. To reduce the cogging torque even more, the technique of slot opening shift is also implemented on the stator slots of analyzed PMSM without reduction in the main performance, including the air-gap magnetic field, the average torque and back-electromotive force (back-EMF).

Findings

Finally, an optimal configuration including the Hat-type magnet poles with halbach magnetization on the rotor and shifted slot openings on the stator is obtained through the CM method, which shows the main reduction in cogging torque and the harmonic content of air-gap magnetic field.

Practical implications

The obtained optimal design is completely practical and is validated by comparing with the corresponding results obtained through finite element method.

Originality/value

This paper presents a new optimal design for integral slot PMSMs, which can include different design considerations, such as the reduction of cogging torque and the total harmonic distortion of air-gap magnetic field by using the CM method.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 20 August 2018

Athanasios Sarigiannidis, Minos Beniakar and Antonios Kladas

This paper aims to introduce a computationally efficient hybrid analytical–finite element (FE) methodology for loss evaluation in electric vehicle (EV) permanent magnet (PM

Abstract

Purpose

This paper aims to introduce a computationally efficient hybrid analytical–finite element (FE) methodology for loss evaluation in electric vehicle (EV) permanent magnet (PM) traction motor applications. In this class of problems, eddy current losses in PMs and iron laminations constitute an important part of overall drive losses, representing a key design target.

Design/methodology/approach

Both surface mounted permanent magnet (SMPM) and double-layer interior permanent magnet (IPM) motor topologies are considered. The PM eddy losses are calculated by using analytical solutions and Fourier harmonic decomposition. The boundary conditions are based on slot opening magnetic field strength tangential component in the air gap in the SMPM topology case, whereas the numerically evaluated normal flux density variation on the surface of the outer PM is implemented in the IPM case. Combined analytical–loss evaluation technique has been verified by comparing its results to a transient magnetodynamic two-dimensional FE model ones.

Findings

The proposed loss evaluation technique calculated the total power losses for various operating conditions with low computational cost, illustrating the relative advantages and drawbacks of each motor topology along a typical EV operating cycle. The accuracy of the method was comparable to transient FE loss evaluation models, particularly around nominal speed.

Originality/value

The originality of this paper is based on the development of a fast and accurate PM eddy loss model for both SMPM and IPM motor topologies for traction applications, combining effectively both analytical and FE techniques.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 7 November 2016

Carlos Guilherme da Costa Neves and Aly Ferreira Flores Filho

The purpose of this paper is to simulate a magnetic gear full integrated generator (MGFIG) to apply in wind power generation.

Abstract

Purpose

The purpose of this paper is to simulate a magnetic gear full integrated generator (MGFIG) to apply in wind power generation.

Design/methodology/approach

A 2D finite element model of the MGFIG was built. The static magnetic torque on air-gaps was obtained by Maxwell stress tensor. In order to simulate the movement of both rotors in relation to the winding and modulators two movement bands were applied.

Findings

It was proved that the MGFIG magnetized with Halbach arrays is able to eliminate the cogging torque, improve the quality of the generated voltage waveform and decrease the core losses and permanent magnet eddy current losses.

Practical implications

The loss coefficients belonging to core material were found from the measured curves provided by an electrical manufacturer.

Originality/value

The originality of this paper is to improve the good characteristics of a MGFIG, such as a simple mechanical structure, good utilization of permanents magnet (PM) materials and lower manufacturing cost, by incorporating Halbach PMs arrays to decrease core and eddy current losses, improve the voltage waveform.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 35 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

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