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The design on magnetic gear (MG) involves determining the gear ratio specific to its application. The gear ratio can be determined by the pole number of the inner rotor, outer rotor and the pole piece. In this research, the cogging torque of several pole pair combinations in concentric magnetic gear (CMG) and rotating pole piece magnetic gear (RPMG) were investigated. The gear ratio equations were initially derived for both CMG and RPMG. Based on these equations, four sets of pole pair combinations were determined. The cogging factor was calculated in each combination. To determine the cogging factor significance towards the cogging torque, the magnetic gears were simulated in 2D finite element software. The result revealed that the lower pole pair combination generates lower cogging torque than the higher pole pair combination. The simulation result also shows that the rate of increase in cogging factor did not correlate directly to the cogging torque in the simulation. It is concluded that the cogging factor is not a suitable tool to access the cogging torque level in CMG and RPMG.

Nowadays flux switching machines (FSMs) offer important role in various high torque applications. In these machines, the flux sources such as field excitation coil (FEC), armature winding and permanent magnet (PM) are located in the stator while leaving the rotor part as winding less. However, FSMs with single stator associate with limited free space for active sources in stator, which leads to some drawbacks of complicated structure, less path for flux flow, flux cancellations, heat generation and demagnetizing effects. To overcome this issue, FSMs using double stator (DS) have been proposed by many researchers which provide more free space for active sources and flux to flow. Therefore, in this paper design and performance of DS FSMs with various excitation sources such as field excitation FE FSMs, PM FSMs and hybrid excitation HE FSMs are reviewed. All the highlighted insights and recommendations of this review will hopefully lead to increasing efforts towards the development of advanced DS FSMs for various applications.

Concentric magnetic gear (CMG) can achieve a torque density of more than 150 kN m/m3 through several modifications of the original structure and the removal of material volume. However, the complexity of such a system may be impractical to assemble and realize. CMG with an alternative condition where the pole piece acts as the outer rotor can deliver higher torque instead of outer pole pair on the same structure. This unconventional condition was known since CMG inception, but it inherits the problem similar to the reluctance machine of high torque ripple. In this paper, a considerably high torque density rotating pole piece magnetic gear is proposed. Several pole pair combinations were evaluated that could yield the highest torque density at lower torque ripple. The best pole pair combination was then optimized through the width reduction of three elements, namely the pole piece, the inner yoke and the outer yoke. By enhancing the structure with the best pole pair combination, the highest torque density achieved was 364.5 kNm/m3. At the same time, the torque ripple was ably kept at below 15%. Unlike other complex structures that yield high torque density, the proposed structure is simpler, easier to assemble and hence should be more cost effective to be produced.

Compact stator structure of flux switching machines (FSMs) encompassing both permanent magnets (PMs) and armature winding slots (AWS) attract research interest whenever high power and density are the basic requirements. However, it also results in temperature rises owing to heat generation by electromagnetic power losses degrading the electromagnetic performance and affecting machine performance. In this study, a segmented permanent magnet (SPM) consequent pole FSM (SPM-CPFSM) is developed, which provides a stator cooling channel (duct) for improved heat dissipation to avoid demagnetization of PM as well as overheating. Furthermore, this study investigates detailed electromagnetic performance analysis and prediction of temperature variation in various machine parts owing to the heat generated by iron, copper, and magnet eddy current losses utilizing coupled electromagnetic-thermal analysis accounting for magnetic flux density variation. In comparison with the 2D analysis, the developed 3D coupled-field analysis more accurately predicts electromagnetic performance and temperature distribution. Analysis reveals that a cooling duct at the stator significantly assists in stator heat dissipation in the axial direction ensuring a safe operating condition of the PMs as well as machine parts to avoid overheating.

The inclusion of a high energy density permanent magnet into magnetic gear improves the machine's torque density. However, it also contributes to eddy current loss, especially in a high-speed application such in electric vehicle. In this paper, the losses from eddy current and iron loss are investigated on concentric magnetic gear (CMG). Torque multiplier CMG is designed with 8/3 gear ratio for this study. Iron loss and eddy current loss are compared and discussed. Based on this study, eddy current loss contributes to almost 96% of the total loss. This finding is hoped to direct the researcher to focus more on reducing loss associated with eddy current loss.

Outer-rotor PM synchronous motor (OR-PMSM) with PM flux has shown to generate high torque and power densities. However, the round rotor used provides high iron loss and weight that affect their speed. This paper, addresses the problem using 24-stator and 14-segments flux switching machine (FSM) whose rotor is passive. Initially, performances of the designed motor such as cogging torque, harmonic distortion, average torque and power are analyzed. The initial design is optimized and the performances between initial and optimized OR-PMFSM designs are compared. The result shows OR-PMFSM has provided low cogging torque and low odd harmonic distortion to operate safely. The torque has increased to 48.81% from initial to optimize design of 240.5Nm and 469.8Nm. A comparative analysis of other motors for high torque such as OR-PMSM, OR-HEFSM and OR-FEFSM are presented. The proposed motor is capable to perform in high torque and high power conditions for automotive applications.

The inclusion of high energy density permanent magnet (PM) in MG contributes to the high eddy current loss in magnetic gear and reduces its efficiency. There was limited research done that focused on gear efficiency behavior over a broader range of speed and in different gear ratios. In this paper, the function of gear efficiency concerning gear ratio and rotational speed is proposed. Torque and eddy current loss data were obtained through transient magnetic analysis using finite element software at several rotational ranges and gear ratios. The analytical approach through mathematical substitution was discussed to confirm the finding in the simulation. The result showed that the gear efficiency decreases as the speed increases. Nonetheless, the gear efficiency revealed improvement in efficiency as the gear ratio increases. Finally, gear efficiency behavior was modeled using the curve fitting method. Subsequently, based on the correlation study, an equation was proposed, yielding a 1% error compared to the new simulated data. With this proposed method and equation, the analysis and estimation of gear efficiency behavior over wider speed and gear ratios are simplified, thus reducing the need to perform simulation over different speeds and gear ratios.

Unique double salient structure of Permanent Magnet Flux Switching Machines (PMFSM) with both Concentrated Armature Winding (CAW) and Permanent Magnet (PM) on stator attract researcher's interest for high speed brushless application when high torque density (T den ) and power density (P den ) are the primal requirements. However, despite of stator leakage flux, high rare-earth PM usage, PMFSM is subjected to slot effects due to presence of both PM and CAW in stator and partial saturation due to double salient structure which generates cogging torque (T cog ), torque ripples (T rip ) and lower average torque (T avg ). To overcome aforesaid demerits, this paper presents Partitioned PM (PPM) Consequent Pole Flux Switching Machine (PPM-CPFSM) with flux barriers to enhance flux modulation, curtail PM usage and diminish stator leakage flux which reduces slotting effects and partial saturation to ultimately reduces T cog and T rlp . In comparison with the existing state of the art, proposed PPM-CPFSM reduces 46.53% of the total PM volume and offer T avg higher up to 88.8%, suppress T rlp maximum up to 24.8%, diminish T cog up to 22.74% and offer 2.45 times T den and P den . Furthermore, torque characteristics of proposed PPM-CPFSM is investigated utilizing space harmonics injection i.e. inverse cosine, inverse cosine with 3 rd harmonics and rotor pole shaping techniques i.e., eccentric circle, chamfering and notching. Detailed electromagnetic performance analysis reveals that harmonics injection suppressed T cog maximum up to 83.5%, T rip up to 40.72% at the cost of 4.71% T avg . Finally, rotor mechanical stress analysis is utilized for rotor withstand capability and 3D-FEA based Coupled Electromagnetic-Thermal Analysis (CETA) for thermal behavior of the developed PPM-CPFSM. CETA reveals that open space along PPM act as cooling duct that improve heat dissipation.

Field excited flux-switching machines (FEFSMs) falls into advance category of synchronous machine. However, most FEFSM structures are comprised of overlapped stator windings, which ends up in taking more space, more copper losses and material costs. Moreover, FSM works on flux-switching principle which made the implementation of field-oriented control (FOC) significantly complex. This study proposes a new structure of single phase FEFSM having segmented rotor and non-overlapped windings for the elimination of above-mentioned drawbacks. Additionally, this study also presents a mechanism to implement FOC without the need of magnetomotive force (MMF) in the rotor. Design of this new topology and its performance characteristics have been analysed through two-dimensional finite element analysis. FOC algorithm has been designed on the basis of sinusoidal variation of stator flux linkage due to rotor position. Experimental results show staggering performance efficiency of about 96% in terms of torque generation when compared to simulation results. Thus, verified the successful implementation of the proposed algorithm on the designed prototype.

Permanent Magnet Flux Switching Machines (PMFSMs) enclose unique features of permanent magnet (PM) synchronous machine, direct current machine, and switch reluctance machine therefore, applicable for high speed brushless AC applications. However, conventional PMFSMs exhibits demerits of high PM volume V PM , high torque ripples T rip , low average torque T avg , lower torque density T den , power density P den and leakage flux. In this paper, a new topology of 12S-13P and 6S-13P E-Core PM Consequent Pole Flux Switching Machines (PMCPFSM) with flux barrier and partitioned PM is proposed that eliminate leakage flux, enhanced flux modulation effects through flux barriers and reduces the PM volume up to 46.53%. Moreover, due to non-linear behaviour of PM and complex stator structure alternate analytical sub-domain model is utilized for initial design and Multi-Variable Geometric Optimization (MVGO) is opted to investigate influence of design parameters on electromagnetic performances such as T avg , T rip , T den and P den . Analysis and comparison with the existing 12S-10P E-Core PMFSM, 6S-10P E-Core PMFSM, 6S-10P C-Core PMFSM and 12S-14P C-Core PMCPFSM reveals that proposed 6S-13P PMCPFSM produced T avg higher up to 88.8%, suppress T rip maximum up to 14.72% and offer 2.45 times T den and P den capabilities, when compared with the aforesaid state of the art.

Flux switching machines (FSMs) encompass unique features of conventional direct current machine, permanent magnet (PM) synchronous machine and switch reluctance machine. Permanent magnet FSM (PMFSM) is capable of high torque density and applicable for high-speed application, however conventional PMFSM exhibits demerits of high PM volume, high torque ripples and significant stator flux leakage. In this paper, a novel consequent pole E-core stator PMFSM is proposed and compared with conventional topology utilising 2D finite-element analysis (2D-FEA). Finite-element analysis revealed that proposed design enhanced flux modulation effects by introducing flux bridges and flux barriers as a result reduced cogging torque by reducing 46.53% of the total PM volume, reduce torque ripples by reducing PM slot effects and reduce flux leakage utilising flux bridges in the stator. Furthermore, analytical model for flux linkages, cogging torque, mechanical torque, no load and on-load magnetic flux density (MFD) is developed for initial design of conventional and proposed model. 2D analytical methodologies resolve equivalent magnetic circuits for open-circuit flux linkages, Fourier analysis for cogging torque, Laplace equations for MFD and Maxwell stress tensor for mechanical torque. Finally, results obtained from 2D-FEA and analytical methodologies are validated and compared.

An axial flux permanent magnet (AFPM) generator is known to be a good candidate for both low and high-speed application. In this paper, a new design of fully coreless multi-stator multi-rotor (MSMR) AFPM generator has been presented with conventional and Halbach magnet arrangement combined with an ironless (epoxy) rotor. For MSMR topology of AFPM machine, back iron is still present in the middle rotor and to maintain the same distribution of magnetic flux, magnets are using on both side of the middle rotor. This paper suggests replacing the middle iron rotors with a single epoxy rotor which reduces the weight of the machine, hence increase power density. On the other hand, for the elimination of iron and magnets in the middle rotor, conventional magnet arrays are used to maintain a continuous flux path. In addition, Halbach array is adopted on the external epoxy rotor to reduce flux leakage on the external sides of the machine. The performance of the proposed generator is investigated in terms of voltage, current, power, power density, and torque ripple. The analytical design approach is first presented and subsequently validated using ANSYS Maxwell® electromagnetic finite element analysis (FEA) software. It is found that a fully coreless MSMR AFPM generator with conventional and Halbach magnet arrays gives higher power density and lower torque ripple with a reduced axial length which is favorable in wind power and pico-hydro applications.

The use of brushes electric motors for propulsion of electric vehicles have come to stay not because of its impressive innovation but mainly due to economic and environmental imperatives. Internal Permanent Magnet Synchronous Motors (IPMSMs) and Flux Switching Machines are being employed in electric vehicles to improve vehicles torque and speed and their performances have proved excellent for gas emission reduction or no fuel usage at all. This paper presents a new outer rotor permanent magnet flux switching machine enveloped by eternal non-ferromagnetic segmental rotor to secure the structure while rotating at very high speed. The segmental rotor is simple and easy to manufacture at low cost employing less material. The geometric topology of this outer rotor is introduced using Eclimo electric scooter parameters. Two dimensional finite element analysis (2D-FEA) models is used to investigate four machine performances namely flux distribution, cogging torque, induced back-EMF, torque and speed versus power characteristics. Results proved high torque and high power sustainability for long distance travel.

Electrical machines for aircraft applications require basic characteristics such as lightweight, high reliability, fault tolerance ability, and torque power and higher densities. Correspondingly, hybrid excitation flux switching machines (HE-FSMs) are capable of producing significant characteristics of high torque and power by improving flux strengthening in the iron core. However, magnetic flux cancellation and leakage in HE-FSMs cause the reduction of flux linkage created by permanent magnet (PM) and field excitation (FE), which leads to deterioration of electromagnetic torque. This study presents magnetic flux performance and comparison of various topologies of HE-FSMs by employing different positions of PMs and FE coils on the stator core. The purpose of a segmented rotor is to deliver a well-defined electromagnetic flux pathway for carrying magnetic flux to nearby armature coil on stator with rotor rotation to improve the flux strengthening. Moreover, magnetic performances of various proposed HE-FSMs at different positions of PMs are investigated and compared based on 2D finite element analysis. Subsequently, the enhanced HE-FSM III has successfully achieved flux strengthening of 22%, torque of 54% and power of 61% more than initial design of HE FSM I, respectively. In conclusion, the proposed HE-FSM structures show the capability to match high torque and power for aircraft applications.

Three-phase field excitation flux switching motor (FEFSM) with salient rotor structure has been introduced with their advantages of rotor easy temperature elimination and controllable FEC magnetic flux. Yet, the salient rotor structure is found to lead a longer magnetic flux path between stator and rotor parts, producing a weak flux linkage along with low torque performances. Hence, a new structure of single-phase FEFSM using segmental rotor with non-overlap windings is proposed with advantages of shorter magnetic flux path, light weight and robust rotor structure. Analysis on fundamental magnetic flux characteristics, armature and FEC magnetic flux linkages, cogging torque, back-Emf, various torque capabilities, refinement of unbalance magnetic flux, and torque-power versus speed characteristics are conducted using 2D FEA through JMAG Designer version 15. The results show that magnetic flux amplitude ratio has been improved by 41.2% while the highest torque and power achieved are 1.45 Nm and 343.8 W, respectively.

This study provides an approach investigation of U and I ferrite core geometrics to improve the power efficiency for Electric Vehicle (EV) inductive wireless charging in dynamic mode. Dynamic wireless charging (DWC) enables recharging of battery pad during the vehicle is on the road. Hence, the design of battery pad must deal with two main factor that led to power leakage such air gap and misalignment. Using ferrite magnetic core, it improves the power transferred by reduce the leakage magnetic radiation between primary and secondary side. Different conditions are investigated on U and I core. The first and second condition is U or I core only at primary side and secondary U or I core only at the secondary side. The last condition is both at primary and secondary side of U or I ferrite core. The purpose of this project is to design a prototype of EV thru several method, design proposed, circuit simulation, pair simulation and prototype development. NI Multisim are used to simulate circuit of WPT for operation validity.

The depletion in energy sources especially oil is among the crucial issues nowadays in Malaysia. Since the quantity of vehicles in Malaysia are increasing, the oil sources are not enough to accommodate all. Wireless charging of Electric Vehicle (EV) has been developed to solve this issue but it gives limited performance due to misalignment, air gap and power loss. Therefore, this project proposed three coil pair design of circular pad coupler for wireless charging of EV. These three pairs were tested for air gap and misalignment cases using simulation and experimental work to find the best coil pair which gives the highest efficiency of power transfer. To design the circular pad, three elements are required in this project which are circuit parameters, geometric properties and experimental work. At first, the circuit parameters are calculated using a specific equation to obtain the inductance value for primary and secondary coil at resonant frequency which is needed for the fabrication of coil process. The simulation for ideal case were done using NI Multisim software to prove the calculated circuit parameters. Then, the geometric properties were calculated and designed in JMAG Designer software. Before designing the circular coil, several geometric parameters like inner diameter, outer diameter and number of turns were set up and calculated. Here, the magnetic flux density and power transfer were observed and measured for each coil pair design. The limitation for this study is that the high cost of copper wire and limited equipment in the laboratory.

In this paper, a novel Consequent Pole Linear Permanent Magnet Flux Switching Machine (CPLPMFSM) with flux bridges and flux barriers is proposed and compared with existing conventional Linear Permanent Magnet Flux Switching Machine (LPMFSM). Proposed machine successfully curtailed demerits of conventional LPMFSM such as high flux leakage, thrust force ripples, peak to peak detent force and Permanent Magnet usage. After electromagnetic analysis utilizing Finite Element Analysis (FEA) software package, expressions combining Lumped Parametric Magnetic Equivalent Circuits, vector potential governed by Laplace Equations, and Maxwell Stress Tensor method are used to develop 2-D analytical model for open circuit flux linkages, no-load and on-load Magnetic Flux Density, detent force and thrust force. Results of 2-D analytical models are validated with corresponding FEA utilizing JMAG Commercial FEA Package v. 18.1 and show good agreement with an accuracy of ~ 97%. Authors are confident to recommend developed 2-D analytical models for initial design of CPLPMFSM.

Compact stator structure of conventional hybrid excited flux switching machines (HE-FSMs) suffer from parasitic effects of iron loss and demagnetization due to spatial harmonics in non-overlapped winding that effect electromagnetic performance i.e. average torque ( $T_{avg}$ ), torque density (Tdvg), average power ( $P_{avg}$ ), power density ( $P_{den}$ ), efficiency (n), flux controllability and flux focusing effects. To overcome the aforesaid demerits, in this paper a novel modular H-type stator core is proposed to improve electromagnetic performance, flux controllability and flux focusing effects. Proposed modular HE-FSMs operating principle is analytically discussed whereas electromagnetic performance with varying flux gaps is investigated through finite element method (FEA). Analysis reveals that despite of better flux focusing effects, modular structure ease manufacturing process, transportation, assembly, and on-site maintenance. Finally, comparison of proposed design with existing state of the art exposes that H-type modular structure offers 42.35% higher $T_{avg}$ , 42% improved $T_{den}$ , better $P_{den}$ by 48.68%, truncate $T_{rip}$ by 13.43% with boost n of 98.6 %.

The main objective of aerospace industry is to produce all electric aircraft (AEA) equipped by electrical devices in coming developments. Electrical machines that provide higher torque densities are gaining more interest for researchers to obtain sustainable direct-drive electrical propulsion system for aircraft applications. In addition to lesser weight and higher torque density, a machine should be “fault tolerant” to applied in aerospace applications. A novel machine for high starting torque, identified as flux switching machine (FSM) was established over the last decade. FSMs comprise all effective sources on stator including robust rotor structure. These machines exhibited higher “torque-to-weight ratios” and reliability. Nonetheless, the challenge of developing a machine suitable for aircraft applications goes far beyond electromagnetic design and much deeper into the field of mechanical systems than traditional ones. Thus, a new double stator (DS) hybrid excitation (HE) FSM design employing segmented rotor is proposed and analyzed in this research work. The suggested design for DS HE-FSM comprises of six field excitation coils (FECs) and six permanent magnets (PMs) as their excitation sources. In this research, investigation of DS HE-FSM is accomplished with respect to flux linkage, back EMF, cogging torque and torque analysis based on 2D FEA.

Nowadays the flux switching machines offer pivotal role in high speed applications. The flux sources (field excitation coil and armature winding or permanent magnet) are confined to the stator leaving rotor completely passive, and thus making the flux switching machine (FSM) more suitable for industrial applications. This paper emphasizes salient rotor pole and non-overlapping windings embedded in electrical machine design possess some pertinent features such as reduced copper losses, low-cost, and usage in high speed applications. The proposed design is analyzed for coil test analysis and flux linkage and torque. On the basis of the analysis performed, it is clear that 12-slot/13-pole has low cogging torque, high flux linkage, and maximum torque, compared with other topologies of outer rotor field excitation FSM. A deterministic optimization technique is adopted to enhance the performance of 12-slot/13-pole design. Further, finite element analysis (FEA) results are verified through Global Reluctance Network (GRN) methodology, which show close resemblance with error less than 1.2%. Hence, it validates the proposed design for outer rotor field excitation FSM direct drive application. The proposed design for hybrid electric vehicle torque characteristic is compared with existing interior permanent magnet synchronous machine (IPMSM) and 6-slot/7-pole wound field flux switching machine (WFFSM).

Flux switching machine (FSM) offer advantages such as rotor robustness and simple driving circuit compared to competing machine. This paper attempts to process the torque, volume and current information from 35 latest Permanent Magnet (PM) FSM publication into a standardized Torque Performance Indicator (TPI), which are torque density, torque constant, torque constant density and torque-magnet ratio. The distribution median shows that torque density, torque constant, torque constant density and torque-magnet ratio are 23.24kNm/m3, 0.43Nm/A, 0.616Nkm/Am3 and 30.79Nm/kg respectively. Among many design variation, outer rotor configuration produces good values as overall in the TPI. This information can be used to guide the machine designer to compare and compete based on the standardized TPI., Flux switching machine (FSM), rakip makineye kıyasla rotor sağlamlığı ve basit sürüş devresi gibi avantajlar sunar. Bu makale, tork, hacim ve akım bilgilerini en son 35 Permanent Magnet (PM) FSM yayınından, tork yoğunluğu, tork sabiti, tork sabit yoğunluğu ve tork-mıknatıs oranı olan standartlaştırılmış bir Torque Performance Indicator (TPI) işlemeye çalışmaktadır. Dağılım medyanı, tork yoğunluğu, tork sabiti, tork sabit yoğunluğu ve tork-mıknatıs oranının sırasıyla 23.24kNm / m3, 0.43Nm / A, 0.616Nkm / Am3 ve 30.79Nm / kg olduğunu göstermektedir. Birçok tasarım varyasyonu arasında, dış rotor konfigürasyonu genel olarak TPI'da olduğu gibi iyi değerler üretir. Bu bilgi, makine tasarımcısına standartlaştırılmış TPI'ya göre karşılaştırma ve rekabet etme konusunda rehberlik etmek için kullanılabilir.

Salient rotor field excitation flux switching synchronous motor (FEFSSM) could be considered as the most feasible candidate in high speed condition owing to their robustness and flux control ability. Nevertheless, the existing FEFSSM utilizes overlapped field excitation coil (FEC) and armature windings, the material cost, motor size and rise of copper loss should be overcome. Besides, deterioration in power and torque densities due to salient structure of rotor weight needs to be improved. In this research, the salient rotor and overlapped windings in conventional FEFSSM are replaced with segmented rotor and non-overlap winding configuration, respectively. Initially, design structures of four FEFSSM topologies i.e., 12S-3P, 12S-6P, 12S-9P and 12S-15P are conducted using 2D finite element analysis (FEA). Then, performances in term of flux linkage, induced voltage, flux enhancement, flux lines and distributions, allowable cogging torque, average torque and maximum power are analyzed. Preliminary results show that the proposed FEFSSM has produced shorter flux path and less copper usage, mainly from the effect of segmental rotor and non-overlap winding. Finally, 12S-6P stator rotor configurations has been selected as the best contenders which deliver the highest flux linkages, peak torque and maximum power of 4.12 mWb, 0.77 Nm and 260 W, respectively

The main advantages of field excitation flux switching motor (FEFSM) are high power, simple structure and, robust rotor, making it very suitable for high-speed applications. However, the previous single-phase FEFSMs using overlap winding and salient rotor have high rotor weight, low torque and low efficiency need to be improved. In this paper, a new structure of single-phase non-overlap winding FEFSMs using salient (SalRoN) and segmental (SegRoN) rotors are proposed. The proposed motors are designed and analysed by 2D-FEA via JMAG Designer version 15. Performances verification is conducted by comparing the various magnetic flux characteristics, torque at multiple combinations of armature current and field excitation current, and torque-power versus speed profiles. In short, the SegRoN design has produced power, initial torque and based speed of 277.5 W, 0.91 Nm and 2,899 rpm which are higher than SalRoN design of 3.2 times, 2.1 times, and 63.9%, respectively. As a conclusion, performances of the proposed non-overlap windings FEFSMs have been successfully compared, SegRoN design having high potential to be applied for lightweight applications.

Flux switching machine (FSM) and conventional synchronous machine (SM) locate flux source differently from each other and it directly affects thermal management knowing that both operate with synchronous speed. Meanwhile, FSM operates with double frequency within the half cycle of synchronous machine region. This paper presents the two synchronous machines extension and compares their electromagnetic performances especially the FSM employing segmented rotor rather than salient rotor pole. The differences between the two PM machines type are highlighted, their maximum torque and flux-weakening capabilities are investigated analytically by 2D-FEA method with due account for the same split ratio of 0.85. The JMAG Designer version 14, is used in the simulation to analyze cogging torque, induced back-EMF and electromagnetic torque performance. Performance of FSM machine is seen to be better than conventional synchronous machine due to location of all active materials on the stationary stator. Output average torque of the presented FSM is seen to increase by 2.9 times or 118% higher than conventional synchronous machine of the same design specifications thereby, projecting FSM using segmented rotor as a viable candidate for vehicle application.

Single phase Field Excitation Flux Switching Machines (FEFSMs) have been the main attention of electric machine and as alternative for it is suitable for high speed application but low torque performance and because it has a robust rotor structure. Currently, the winding of field excitation (FE) and armature are wound in distributed configuration and caused the motor size and material cost to increase which eventually leads to high copper loss. Therefore, this paper investigates the no-load and load finite-element analysis (FEA) and comparison between 8 slots and 16 slots with four different rotor number for each slot design. The rotor pole in segmental structure, concentric armature and FEC windings. The performances in No-load analysis is the coil arrangement, back-EMF, flux linkage, cogging torque, flux line and flux distribution of the propose machines. The study is performed by applying a 2-D FEA and compare the load analysis such as torque and power to determine the best performance. The 2-D FEA results shows that the best combination of slot-pole configurations is the 16 Slots 8Pole because of its highest torque and power output, 3.49Nm and 0.31kW respectively.

This paper explains the high reliability of a segmental stator for fault-tolerant of Switched-Flux Permanent Magnet Machines (SFPMMs). The advantage of SFPMMs when compared to induction machines (IMs) and switch reluctance machines (SRMs), is because it has the most power dense, excellent overload capability and the machine structure is designed to limit fault current. High power and torque output give reasons to the SFPMM to be solely selected to obtain a full torque needed and high-power factor at high speed region compared to SRM which have a limited torque, power and low maximum speed operation. Therefore, the theoretical and technical literature of the common cause of electric motor are discussed. In this paper, it is explained briefly about the proposed segmental stator 12Slot-12Pole SFPMM, flux linkage analysis, back-emf, cogging torque, torque and power output performance in 30Arms/mm2 armature current density. Further-more, this paper explains the advantages of segmental stator specifically as fault tolerance in stator winding such as line-to-line, line-to-ground and three phase faults. Moreover, this paper discussed about the source of failure for the machine itself and what is the minimum reliability requirements of a fault-tolerant machine.

Switched Flux Permanent Magnet Machines (SFPMM) exhibit pivotal role in high speed applications when high torque and power density are essential requirements. However, existing conventional SFPMM utilizes more Permanent Magnet (PM) volume results in overall increase of machine cost and weight. Moreover, high PM usage enhance interaction with rotor core that ultimately generate cogging torque (no load torque) which introduce vibration and acoustic noise. In additional, conventional SFPMM exhibits flux leakages from the PMs end which effects electromagnetic performance. In this paper, a novel consequent pole SFPMM (CPSFPMM) with flux bridges, flux barriers and reduced partition PMs is introduced which leads in reduction of total machine cost, weight and decrease of the cogging torque. Moreover, rotor pole analysis is carried out for optimal combination of the rotor poles number combination for initial optimal design of CPSFPMM with key performance indicators such as open-circuit flux linkage, cogging torque, mechanical torque, Total harmonic distortion (THD), torque ripple ratio, average torque and average power characteristics. Based on Finite Element Analysis (FEA) on commercial FEA package JMAG v. 14, CPSFPMM with 12-stator slot and 13 rotor poles is searched out to be optimal design with comparatively best electromagnetic performance. Moreover, proposed novel CPSFPMM is compared with existing conventional SFPMM. Analysis reveals that proposed CPSFPMM utilized 77% PM volume, which reduce machine cost, weight, and offer 124.06% peak to peak open-circuit flux linkage, 52.74% peak to peak cogging torque, 99.2% average torque, 34.67% THD and 77.64% torque ripple ratio when compared with existing conventional SFPMM.

Recently, a three-phase field-excitation flux switching motor (FEFSM) with salient rotor structure has been introduced with their advantages of easy rotor temperature removal and controllable field excitation coil (FEC) magnetic flux particularly suitable for high torque, high power, and high-speed diverse performances. Nevertheless, the salient rotor structure is found to lead a longer magnetic flux path between stator and rotor producing weak flux linkage along with low torque performances. Besides, the overlap armature coil and FEC windings yield high coil end length, producing much high copper loss and large motor size. In this paper, a new FEFSM using segmental rotor with non-overlap armature coil and FEC windings is proposed. The shorter magnetic flux path of the proposed segmental rotor is noticeably more focused to produce much higher torque while the non-overlap armature and FEC will reduce the copper loss and motor weight. Both FEFSMs with salient and segmental rotors are designed using 2-D-FEA JMAG Designer version 14.1 for comparison. As a result, magnetic flux of the segmental rotor design is 11 times higher than the salient rotor structure mainly due to shorter magnetic flux linkage between two stator teeth and single rotor segment. The torque and power of 0.91 Nm and 293 W, respectively, are obtained from the new FEFSM which are much higher than salient rotor design. In addition, the simulation and experimental results show a good agreement in back-electromotive force amplitude and waveform at various speeds, as well as similar increment of torque versus FEC current characteristics. As the conclusion, the proposed FEFSM with non-overlap and segmental rotor structure has produced much higher flux, with significant improvement of torque and power performances compared with existing FEFSM with salient rotor.

Permanent magnet flux switching machine (PMFSM) has the advantages of solid design structure, high torque performances, and high efficiency. The method to increase performance and decrease the cost of the motor through a selection of numbers of slot and pole is a major issue that needs to be solved. Therefore, to further improve the electromagnetic torque, a novel 4-4S-8P multi-tooth, 4S-8P segmental-tooth and single-tooth PMFSM machine respectively is proposed based on the slot pole analysis performance. Hence, the performance is including the flux linkage, cogging torque, back-electromotive force (back-emf), output torque, and power performance. The results display that the various tooth shape topology have a large impact on the performance design. JMAG Designer version 14.3 under 2D finite element analysis (2D-FEA) are used to complete the analysis. The results show that the right combination of a single-tooth 4S-8P PMFSM structure is the best choice according to the high performance of torque analysis.

The use of a segmented rotor electric motor for lightweight electric vehicle applications has gained a lot of attention since the motor must have a high output torque and output power. Segmented rotor motors have performance indices that should be taken into consideration because not every machine is effective. Recently, permanent magnet flux switching machine (PMFSM) in salient rotor has become attractive for provide high torque and power. Undesirably, salient rotor inherited high iron loss and winding loss, Furthermore, PMFSM uses high PM volume and more flux leakage resulting in poor performance. This paper deals with a novel structure of modular rotor PMFSM with non-overlapping winding with minimal iron loss, high torque and high power. 2D finite element analysis (FEA) is used to investigate the performance of proposed motor in JMAG Designer 14.1. Three-phase operation of 12S/10P modular rotor PMFSM was designed and analysed based on the cogging torque, induced back emf, output torque and output power performances. The proposed motor securing the initial torque of 33.30 Nm and power of 12Kw at maximum current density of 30Arms/mm2. From the result it is concluded that modular rotor based PMFSM motor is suitable for light weight electric vehicles.

To empower safe, economical and eco-friendly sustainable solution for enhancing oil and gas productivity from deep water reservoirs, new downhole technologies are recommended. Since electric machine plays leading role in the downhole application, it is a squeezing requirement for researchers to design and develop advanced electric machine. The Recent improvement in technology and uses of high-temperature magnets, permanent magnet flux switching machine (PMFSM) has become one of the appropriate contenders for offshore drilling but fewer designed for downhole due to ambient temperature. Therefore this comprehensive study deals with the design optimization and performance analysis of outer rotor PMFSM for the downhole application. Preliminary, the basic design parameters needed for machine design are calculated mathematically. Then the design refinement technique is implemented through deterministic method. Finally, initial and optimized performance of the machine is compared and as a result the output torque is increase from 16.39 Nm to 33.57 Nm while diminishing the cogging torque and PM weight up to 1.77 Nm and 0.79 kg, respectively. Therefore, it is concluded that purposed optimized design is suitable for the downhole application.

Purpose The paper aims to propose and compare two new structures of a three-phase wound field salient rotor (WFSR) switched-flux motor (SFM) with 24 stator slots and 10 or 14 rotor poles, respectively, for high-speed operation. Design/methodology/approach The paper outlines the motor general construction and design concept of proposed machines. Flux linkage, average torque, rotor mechanical strength and torque–speed characteristics of both machines were analyzed and compared by two-dimensional finite element analysis (2D-FEA). Deterministic optimization method was adopted to enhance the characteristics of 24Slot-10Pole WFSR SFM. Findings The paper provides simulation results and discusses how 24Slot-10Pole WFSR SFM structure is superior to the 24Slot-14Pole in the aspects of flux linkage, average torque and power. It further concludes that the optimized design of 24Slot-10P has achieved 58 and 72 per cent higher average torque and power compared to initial design, as well as high average torque and power compared to 24Slot-14P design. Originality value Optimized structure of the 24Slot-10Pole WFSR SFM with non-overlapping windings has been proposed.

Purpose The purpose of this paper is to address a fundamental study and performance analysis of a proposed 6Slots-10Poles permanent magnet flux switching machine (PMFSM) using straight rotor (StR) and 6Slots-8Poles PMFSM with spanned rotor (SpR) structure. Design/methodology/approach Design configuration of the proposed machine was developed using commercial finite element analysis package and JMAG-Designer V.14 software, which provides two-dimensional finite element solver throughout the investigation. An electromagnetic performance analysis is carried out and compared over the two proposed topologies which consist of machines no-load and under-load conditions. Findings This paper demonstrates the finding of the proposed StR structure which consist of more favorable three-phase sinusoidal feature, lower cogging torque and higher output torque. Flux density attributes reveal higher established magnetizing flux concentration in StR compared with SpR. Consequently, the StR structure requires low armature current before it may start to rotate and provides better robust construction with less material consumption and cost. Originality/value This paper describes the novel design of a new PMFSM configuration pertinent for high-speed applications.

This paper presents the improvement of electromagnetic torque performance of segmental stator(Segta) 12Slot-12Pole PMFSM based on the design optimisation. It derives and implement using the Deterministic Optimisation Method (DOM) which solely involve at the geometrical structure of the motor. Therefore, the parameter that was involves are explained in this paper. DOM is a local optimisation method and involves many cycles of parameter improvement in order to obtain an optimum performance based on the final parameter achieved. Furthermore, the overall mass of the permanent magnet was retained at 2 kg throughout the whole optimisation process. Prior to the initial average torque performance from the previous research which was 222.30 Nm and the maximum power output is 243.63 kW, the main objective was to achieve a higher average torque and maximum power output performance by applying design structure refinement. The initial design structure, parameter and specification are calculated and specified based on conventional 12S-14P PMFSM. Each parameter (P1-P5) that involves with optimisation are explained in this paper. The target of this optimisation is to achieve torque performance higher than the initial design torque output. In which, the optimise design able to achieve a higher average torque output, 252.24 Nm compared to the initial design torque performance.

In this paper the electromagnetic flux analysis of dual stator hybrid excitation flux switching machines (DS HESFMs) with segmented rotor are presented. The objective of the research is to develop an electric motor for the driven electromechanical actuator meant to use for aerospace applications. The benefit of designing a machine with directly driven system is to entirely remove the transitional gear box arrangements with having lesser component count and reduced jamming possibility. The proposed design of DS HEFSM with segmental rotor is examined in this paper as a potential solution for actuators. The key purposes of the design are to reduce the overall weight, volume and enhance fault tolerance ability. The proposed DS HESFSM design shows simple structure, that includes six number of field excitation coils (FECs) are inserted in outer stator slots with six armature coils (ACs) while, six permanent magnets (PMs) are situated in the inner stator. Besides, DS HESFM structure is investigated at no load and load conditions using "commercial 2D FEA package, JMAG-designer ver. 14.0," released by JSOL Corporation.