Torque and back-emf in hybrid excited claw pole generator

2018 ◽  
Vol 37 (4) ◽  
pp. 1342-1353 ◽  
Author(s):  
Marcin Wardach
Keyword(s):  
Permanent Magnets ◽  
Experimental Results ◽  
Original Design ◽  
Element Analysis ◽  
Simulation Research ◽  
Cogging Torque ◽  
Content Type ◽  
Excitation Coil ◽  
New Construction ◽  
Torque Values

Purpose The paper aims to present the hybrid excited claw pole generator design, simulation and experimental results. The prototype has claw poles on two rotor sections, between which an excitation coil is located. The innovation of this machine is permanent magnets location on claws of one part of the rotor. The paper presents construction of the machine and analysis of the current in the excitation control coil influence on the electromagnetic torque, cogging torque and back-emf values. Presented studies enabled the determination of the torque and the back-emf for both: the strengthening and the weakening of magnetic field. Design/methodology/approach In the study, finite element analysis was used to perform simulation research. Then, based on the simulation studies, an experimental model was built. The paper also presents selected experimental results. Findings Achieved results show that the proposed machine topology allows to eliminate the disadvantages mentioned in paper, i.e. necessary to introduce special areas inside the machine to limit magnetic flux leakage or its complicated construction. Research limitations/implications The obtained cogging torque values and back-emf pulsation are still relatively high. In the near future, some of known techniques for reducing these pulsations can be applied, including the use of magnetic wedges, changing shapes of rotor’s poles and/or skewing of permanent magnets. Practical implications The proposed solution can be used in wind turbines as a generator. Originality/value The paper presents an original design of a new construction of a hybrid-excited claw pole machine and also an excitation current influence on cogging torque and back-emf values.

Novel hybrid excited machine with flux barriers in rotor structure

2018 ◽  
Vol 37 (4) ◽  
pp. 1489-1499 ◽  
Author(s):  
Marcin Wardach ◽  
Ryszard Palka ◽  
Piotr Paplicki ◽  
Michal Bonislawski
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Control Method ◽  
Permanent Magnet Machines ◽  
Original Design ◽  
Element Analysis ◽  
Flux Control ◽  
Content Type ◽  
Field Weakening ◽  
Rotor Structure

Purpose Permanent magnet (PM) electrical machines are becoming one of the most popular type of the machines used in electrical vehicle drive applications. The main drawback of permanent magnet machines, despite obvious advantages, is associated with the flux control capability, which is limited at high rotor speeds of the machine. This paper aims to present a new arrangement of permanent magnets and flux barriers in the rotor structure to improve the field weakening control of hybrid excited machines. The field weakening characteristics, back-emf waveforms and efficiency maps of this novel machine have been reported. Design/methodology/approach In the study, finite element analysis was used to perform simulation research. Then, based on the simulation studies, an experimental model was built. The paper also presents selected experimental results. Findings Obtained results show that the proposed machine topology and novel control strategy can offer an effective flux control method allowing to extend the maximal rotational speed of the machine at constant power range. Practical implications The proposed solution can be used in electric vehicles drive to extend its torque and speed range. Originality/value The paper presents original design and results of research on a new solution of a hybrid excited machine with magnetic barriers in a rotor.

Analytical sub-domain model for predicting open-circuit field of permanent magnet vernier machine accounting for tooth tips

2016 ◽  
Vol 35 (2) ◽  
pp. 624-640 ◽  
Author(s):  
Y. Oner ◽  
Z.Q. Zhu ◽  
L.J. Wu ◽  
X. Ge
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Open Circuit ◽  
Air Gap ◽  
Domain Model ◽  
Direct Drive ◽  
Element Analysis ◽  
Cogging Torque ◽  
Content Type ◽  
Flux Modulation

Purpose – Due to high electromagnetic torque at low speed, vernier machines are suitable for direct-drive applications such as electric vehicles and wind power generators. The purpose of this paper is to present an exact sub-domain model for analytically predicting the open-circuit magnetic field of permanent magnet vernier machine (PMVM) including tooth tips. The entire field domain is divided into five regions, viz. magnets, air gap, slot openings, slots, and flux-modulation pole slots (FMPs). The model accounts for the influence of interaction between PMs, FMPs and slots, and radial/parallel magnetization. Design/methodology/approach – Magnetic field distributions for slot and air-gap, flux linkage, back-EMF and cogging torque waveforms are obtained from the analytical method and validated by finite element analysis (FEA). Findings – It is found that the developed sub-domain model including tooth tips is very accurate and is applicable to PMVM having any combination of slots/FMPs/PMs. Originality/value – The main contributions include: accurate sub-domain model for PMVM is proposed for open-circuit including tooth-tip which cannot be accounted for in literature; the model accounts the interaction between flux modulation pole (FMP) and slot; developed sub-domain model is accurate and applicable to any slot/FMP/PM combinations; and it has investigated the influence of FMP/slot opening width/height on cogging torque.

Analysis of torque ripple and fault-tolerant capability for a 16/10 segmented switched reluctance motor in HEV applications

2019 ◽  
Vol 38 (6) ◽  
pp. 1725-1737
Author(s):  
Xiaodong Sun ◽  
Jiangling Wu ◽  
Shaohua Wang ◽  
Kaikai Diao ◽  
Zebin Yang
Keyword(s):  
Fault Tolerant ◽  
Switched Reluctance Motor ◽  
Torque Ripple ◽  
Experimental Results ◽  
Element Analysis ◽  
Content Type ◽  
Switched Reluctance ◽  
Output Torque ◽  
Reluctance Motor ◽  
Lower Torque

Purpose The torque ripple and fault-tolerant capability are the two main problems for the switched reluctance motors (SRMs) in applications. The purpose of this paper, therefore, is to propose a novel 16/10 segmented SRM (SSRM) to reduce the torque ripple and improve the fault-tolerant capability in this work. Design/methodology/approach The stator of the proposed SSRM is composed of exciting and auxiliary stator poles, while the rotor consists of a series of discrete segments. The fault-tolerant and torque ripple characteristics of the proposed SSRM are studied by the finite element analysis (FEA) method. Meanwhile, the characteristics of the SSRM are compared with those of a conventional SRM with 8/6 stator/rotor poles. Finally, FEA and experimental results are provided to validate the static and dynamic characteristics of the proposed SSRM. Findings It is found that the proposed novel 16/10 SSRM for the application in the belt-driven starter generator (BSG) possesses these functions: less mutual inductance and high fault-tolerant capability. It is also found that the proposed SSRM provides lower torque ripple and higher output torque. Finally, the experimental results validate that the proposed SSRM runs with lower torque ripple, better output torque and fault-tolerant characteristics, making it an ideal candidate for the BSG and similar systems. Originality/value This paper presents the analysis of torque ripple and fault-tolerant capability for a 16/10 segmented switched reluctance motor in hybrid electric vehicles. Using FEA simulation and building a test bench to verify the proposed SSRM’s superiority in both torque ripple and fault-tolerant capability.

scholarly journals Mitigation Method of Slot Harmonic Cogging Torque Considering Unevenly Magnetized Permanent Magnets in PMSM

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3887
Author(s):  
Jeong ◽  
Lee ◽  
Hur
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Permanent Magnet Synchronous Motor ◽  
Harmonic Component ◽  
Magnetic Flux Density ◽  
Element Analysis ◽  
Cogging Torque ◽  
Maxwell Stress Tensor ◽  
The Finite Element Analysis ◽  
Harmonic Components

This paper presents a mitigation method of slot harmonic cogging torque considering unevenly magnetized magnets in a permanent magnet synchronous motor. In previous studies, it has been confirmed that non-uniformly magnetized permanent magnets cause an unexpected increase of cogging torque because of additional slot harmonic components. However, these studies did not offer a countermeasure against it. First, in this study, the relationship between the residual magnetic flux density of the permanent magnet and the cogging torque is derived from the basic form of the Maxwell stress tensor equation. Second, the principle of the slot harmonic cogging torque generation is explained qualitatively, and the mitigation method of the slot harmonic component is proposed. Finally, the proposed method is verified with the finite element analysis and experimental results.

Novel switched flux machine with radial and circumferential permanent magnets

2016 ◽  
Vol 35 (2) ◽  
pp. 473-492 ◽  
Author(s):  
M.M.J. Al-ani ◽  
Z.Q. Zhu
Keyword(s):  
Permanent Magnets ◽  
Outer Region ◽  
Optimization Procedure ◽  
Design Parameters ◽  
Element Analysis ◽  
Content Type ◽  
Copper Loss ◽  
Rotor Pole ◽  
Internal Rotor ◽  
External Rotor

Purpose – The paper purposes a novel SFPM machine topology with radial and circumferential permanent magnets (PMs). The paper aims to discuss this issue. Design/methodology/approach – In order to reduce the flux leakage in the stator-outer region and consequently achieve higher magnetic material utilization in switched flux permanent magnet (SFPM) machine, a novel topology with radial and circumferential PMs is proposed. This topology (SFRCPM) has the same structure as conventional SFPM (CSFPM) machine except of the additional set of radially magnetized PMs located around the back iron and surrounded by a laminated ring frame. Using finite element analysis (FEA) the influence of the design parameters on the performance is investigated in order to obtain an effective optimization procedure. Internal and external rotor SFRCPM machines with either NdFeB or ferrite magnets are investigated, optimized and compared with the CSFPM machine having the same size, copper loss and stator/rotor pole combination. Findings – It is concluded that comparing SFRCPM with its CSFPM machine counterpart, internal rotor SFRCPM machine can achieve high PM flux-linkage per magnet volume, however reduced slot area leads to low output torque, whereas external rotor SFRCPM machine can produce higher torque and torque per magnet volume. Originality/value – This paper proposes a novel SFPM machine topology.

A new optimal design of surface mounted permanent magnet synchronous motors with integral slot per pole

2018 ◽  
Vol 37 (1) ◽  
pp. 136-152
Author(s):  
Behrooz Rezaeealam ◽  
Farhad Rezaee-Alam
Keyword(s):  
Magnetic Field ◽  
Optimal Design ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Air Gap ◽  
Permanent Magnet Synchronous Motors ◽  
Cogging Torque ◽  
Content Type ◽  
Synchronous Motors ◽  
Air Gap Magnetic Field

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.

Influence of fiber stacking sequences and matrix materials on mechanical and vibration behavior of jute/carbon hybrid composites

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sathiyamoorthy Margabandu ◽  
Senthil Kumar Subramaniam
Keyword(s):  
Tensile Strength ◽  
Hybrid Composites ◽  
Low Cost ◽  
Laminated Composite ◽  
Experimental Results ◽  
Element Analysis ◽  
Content Type ◽  
Vibration Behavior ◽  
Damping Behavior ◽  
Composite Models

Purpose The study aims to investigate the influence of fabric hybridization, stacking sequences and matrix materials on the tensile strength and damping behavior of jute/carbon reinforced hybrid composites. Design/methodology/approach The hybrid composites were fabricated with different sequences of fabric plies in epoxy and polyester matrix using a hand layup technique. The tensile and vibration characteristics were evaluated on the hybrid laminated composite models using finite element analysis (FEA), and the results were validated experimentally according to ASTM standards. The surface morphology of the fractured specimens was studied using the scanning electron microscope. Findings The experimental results revealed that the position of jute layers in the hybrid composites has a significant influence on the tensile strength and damping behavior. The hybrid composite with jute fiber at the surface sides and carbon fibers at the middle exhibited higher tensile strength with superior damping properties. Further, it is found that the experimental results are in good coherence with the FEA results. Originality/value The less weight and low-cost hybrid composites were fabricated by incorporating the jute and carbon fabrics in interply configurations. The influences of fabric hybridization, stacking arrangements and matrix materials on the tensile and vibration behavior of jute/carbon hybrid composites have been numerically evaluated and the results were experimentally validated.

Cogging Torque Reduction in Permanent Magnet Brushless DC Motor by using Various Design Modification Techniques

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
M. Arun Noyal Doss ◽  
A. Ananthi Christy ◽  
Aishwarya Manibala Jha ◽  
Abhishek Iyer ◽  
R. Varun
Keyword(s):  
Computer Aided Design ◽  
Brushless Dc Motor ◽  
Bldc Motor ◽  
Element Analysis ◽  
Design Modification ◽  
Cogging Torque ◽  
Brushless Dc ◽  
Permanent Magnet Brushless Dc ◽  
Torque Values ◽  
Aided Design

Cogging torque is a problem for continuous motion applications like scanning, contouring and mainly positioning applications that requires smooth and accurate motion. It degrades the performance and the life of the motor. Cogging torque cannot be completely omitted but can be reduced drastically using various design modification techniques. This paper focuses on reducing cogging torque in BLDC using three different techniques like stator slot modification, rotor magnet modification and skewing of stator slots and rotor magnets. The result obtained by combining these three techniques has yielded a new model with reduced cogging torque and trapezoidal Back Electromotive Force as compared to the conventional BLDC motor. Also, the cogging torque values for different rotor magnets and stator slots shapes are calculated and studied using Finite Element Analysis (FEA). A detailed thermal analysis of the same model presents the temperature and heat flow plots using Computer Aided Design (CAD).

Sinusoidal PWM Techniques in Rotor Pole Segmentation to Reduce Permanent Magnet Synchronous Machine Torque Ripple

2020 ◽  
Author(s):  
Khristian M. de Andrade Jr ◽  
Hugo E. Santos ◽  
Wellington M. Vilela, ◽  
Geyverson T. de Paula
Keyword(s):  
Permanent Magnets ◽  
Torque Ripple ◽  
Synchronous Machine ◽  
Element Analysis ◽  
Cogging Torque ◽  
Torque Ripple Reduction ◽  
Rotor Poles ◽  
Rotor Pole ◽  
Ripple Reduction ◽  
Torque Ripples

Torque ripples can cause mechanical stress in electrical machines, among otherproblems. The present paper proposes three methods to reduce these ripples in the permanent magnets synchronous machine considering rotor poles design. These methods consist in segmenting the rotor poles, with width and distances between segments obtained by SPWM techniques. The modulating wave is a sinwave which has the same frequency as the air gap flux density fundamental harmonic. Method 1 contemplates the unipolar SPWM technique, whereas methods 1 and 2 used the bipolar SWPM technique. Furthermore, the equations used to predict the cogging torque behavior are presented and verified by means of a finite element analysis. The torque ripple reduction is achieved due to the elimination of back-electromotive force harmonics and the decrease in the cogging torque peak. Method 1 has proved to be the most effective, reducing the torque ripple by 51.38% and 76.61% for the 4-pole and 8-pole machines, respectively. In addition, the magnet volume utilized has been reduced by 22.55% for the 4-pole machine, but the average torque value has been reduced by 18.7%. It is worth mentioning that the proposed methods do not require skewing to reduce the torque ripple.

Design technique for leakage current reduction in surge arrester using gravitational search algorithm and imperialist competitive algorithm

2018 ◽  
Vol 37 (1) ◽  
pp. 357-374 ◽  
Author(s):  
Nurul Ain Abdul Latiff ◽  
Hazlee Azil Illias ◽  
Ab Halim Abu Bakar ◽  
Syahirah Abd Halim ◽  
Sameh Ziad Dabbak
Keyword(s):  
Leakage Current ◽  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Imperialist Competitive Algorithm ◽  
Original Design ◽  
Element Analysis ◽  
Content Type ◽  
Competitive Algorithm ◽  
Surge Arresters ◽  
Gravitational Search

Purpose Leakage current is one of the factors, which can contribute towards degradation of surge arresters. Thus, the purpose of this paper is to study on leakage current within surge arresters and improvement on their design. Design/methodology/approach In this work, a three-dimensional model geometry of 11 kV zinc oxide surge arrester was designed in finite element analysis and was applied to calculate the leakage current under normal operating condition and being verified with measurement results. The optimisation methods were used to improve the arrester design by minimising the leakage current across the arrester using imperialist competitive algorithm (ICA) and gravitational search algorithm (GSA). Findings The arrester design in reducing leakage current was successfully optimised by varying the glass permittivity, silicone rubber permittivity and the width of the ground terminal of the surge arrester. It was found that the surge arrester design obtained using ICA has lower leakage current than GSA and the original design of the surge arrester. Practical implications The comparison between measurement and simulation enables factors that affect the mechanism of leakage current in surge arresters to be identified and provides the ideal design of arrester. Originality/value Surge arrester design was optimised by ICA and GSA, which has never been applied in past works in designing surge arrester with minimum leakage current.

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