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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.

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.

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.

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.

This paper aims to further develop stator permanent magnet (PM) type memory machines by providing generalized design guidelines for double-stator memory machines (DSMMs) with hybrid PMs. This paper discusses the design experience of DSMMs and presents a comparative study of radial magnetization (RM) and circumferential magnetization (CM) types.

It begins with an introduction to RM and CM operating principles and magnetization mechanisms. Then, a comparative study is conducted for one of the RM-DSMM rotor pole pairs, inner and outer stator clamping angles and low coercive force PMs thickness. Finally, the two machines’ finite element simulation performance is compared. The validity of the proposed machine structure is demonstrated.

In this paper, the double-stator structure is extended to parallel hybrid PM memory machines, and two novel DSMMs with RM and CM configurations are proposed. Two types of DSMMs have PMs and magnetizing windings on the inner stator and armature windings on the outer stator. The main difference between the two is the arrangement of PMs on the inner stator.

Conventional stator PM memory machines have geometrical space conflicts between the PM and armature windings. The proposed double-stator structure can alleviate these conflicts and increase the torque density accordingly. In addition, this paper contributes to comparing the arrangement of hybrid PMs for DSMMs.

The purpose of this paper is to propose a novel type of switched flux PM machines with two separate stators.

2D-FEA is employed to analyze the electromagnetic performance of the proposed machines. Moreover, the results are validated by experiments.

The proposed machine has higher torque density, less unbalanced magnetic force on the modulating steel piece and uses less PM volume.

The proposed machine is a low-cost novel topology with different rotor pole combinations.

The purpose of this paper is to analyze electromagnetic performance and develop an analytical approach to find the suitable coil combination and no-load flux linkage of the proposed hybrid excited consequent pole flux switching machine (HECPFSM) while minimizing the drive storage and computational time which is the main problem in finite element analysis (FEA) tools.

First, a new HECPFSM based on conventional consequent pole flux switching permanent machine (FSPM) is proposed, and lumped parameter magnetic network model (LPMNM) is developed for the initial analysis like coil combination and no-load flux linkage. In LPMNM, all the parts of one-third machine are modeled which helps in reduction of drive storage, computational complexity and computational time without affecting the accuracy. Second, self and mutual inductance are calculated in the stator, and dq-axis inductance is calculated using park transformation in the rotor of the proposed machine. Furthermore, on-load performance analysis, like average torque, torque density and efficiency, is done by FEA.

The developed LPMNM is validated by FEA via JMAG v. 19.1. The results obtained show good agreement with an accuracy of 96.89%.

The proposed HECPFSM is developed for high-speed brushless AC applications like electric vehicle (EV)/hybrid electric vehicle (HEV).

The proposed HECPFSM offers better flux regulation capability with enhanced electromagnetic performance as compared to conventional consequent pole FSPM. Moreover, the developed LPMNM reduces drive storage and computational time by modeling one-third of the machine.

This paper aims to present an analytical electromagnetic model for wound rotor synchronous machines with a salient-pole rotor structure based on the two-dimensional subdomain technique.

The machine is divided into five active sub-regions: stator slots, stator slot openings, air gap, rotor slots and rotor slot openings. For each sub-region, the governing partial differential equations are derived and solved analytically.

The magnetic flux density distributions in all active sub-regions are analytically computed and other quantities such as back-emf, inductances, electromagnetic torque and unbalanced magnetic forces are also analytically calculated. The results of the analytical model are compared to those obtained from the finite element analysis to show the accuracy of the proposed model.

The two-dimensional analytical model of a wound rotor salient-pole synchronous machine using the sub-domain technique is the main contribution of the research.

The purpose of this paper is to explore the relationship of fluid flow and heat transfer inside the generator, a large hydro-generator is taken for an example and the temperature field in the generator is calculated according to computation of fluid field by using of corresponding mathematics methods based on fluid mechanical theory and heat transfer theory.

To calculate the temperature field of the generator more accurately, a large-scale hydro-generator is taken as an example and the mathematical model and physical model of 3D stator temperature field and fluid field are established. And the calculation results of the fluid field are applied into the physics field of generator, coupled relationship between fluid field and temperature field was calculated by using of finite volume method and finite element method, respectively. The temperature fields based on fluid fields and the effect of different fluid flow state on generator temperature were analyzed and compared.

The calculated results shows show good agreement with the measured results, meanwhile the effect of different fluid field state on the temperature field is analyzed and the relationship between temperature fields and fluid fields is achieved, which will provide a theoretical basis for ventilation structure design and calculation of synthesis physical fields.

The relationship between temperature fields and fluid fields is obtained, providing a theoretical basis for ventilation structure design and calculation of synthesis physical fields.

The purpose of this paper is to analytically predict the on-load field distribution and electromagnetic performance (induced voltage, electromagnetic torque, winding inductances and unbalanced magnetic force) of dual-stator consequent-pole permanent magnet (DSCPPM) machines using subdomain model accounting for tooth-tip effect. The finite element (FE) results are presented to validate the accuracy of this subdomain model.

During the preliminary design and optimization of DSCPPM machines, FE method requires numerous computational resources and can be especially time-consuming. Thus, a subdomain model considering the tooth-tip effect is presented in this paper. The whole field domain is divided into four different types of sub-regions, where the analytical solutions of vector potential in each sub-region can be rapidly calculated. The proposed subdomain model can accurately predict the on-load flux density distributions and electromagnetic performance of DSCPPM machines, which is verified by FE method.

The radial and tangential components of flux densities in each sub-region of DSCPPM machine can be obtained according to the vector potential distribution, which is calculated based on the boundary and interface conditions using variable separation approach. The tooth-tip effect is investigated as well. Moreover, the phase-induced voltage, winding inductances, electromagnetic torque and X-axis/Y-axis components of unbalanced magnetic forces are calculated and compared by FE analysis, where excellent agreements are consistently exhibited.

The on-load field distributions and electromagnetic performance of DSCPPM machines are analytically investigated using subdomain method, which can be beneficial in the process of initial design and optimization for such DSCPPM machines.

To improve the power density and generation efficiency of the tubular permanent magnetic linear generators (TPMLGs) under realistic sea-stator condition, a TPMLG with 120° phase belt toroidal windings (120°-TPMLG) for wave energy conversion is proposed in this paper.

First, the structure of the 120°-TPMLG is introduced and its operation principle is analyzed. Second, the design process of the 120°-TPMLG is described. Meanwhile, the finite-element models of the 120°-TPMLG and the TPMLG with traditional fractional pitch windings (T-TPMLG) are established based on the similar overall dimensions. Then, the electromagnetic characteristics of the 120°-TPMLG are analyzed, such as air gap flux density, back electromotive force and load voltage. Finally, a comparative analysis of the magnetic flux density, flux linkage, load and no-load performance of the two generators are conducted.

The result shows that the 120°-TPMLG has higher power density and generation efficiency than the T-TPMLG.

This paper proposes a TPMLG with 120° phase belt toroidal windings (120°-TPMLG) to improve the power density and generation efficiency.

This study aims to extract an analytical model for five-phase fault-tolerant permanent-magnet vernier machines (FTPMVMs) based on the analytical solution of Maxwell’s equations, which has some advantages than the finite element model.

FTPMVMs enhance the torque density by combining the vernier characteristics and the fault-tolerant feature. The principle operation of FTPMVMs is discussed based on the magnetic field modulation due to both permanent magnets and armature current. The analytical solution of the magnetic vector potential in each sub-region is obtained based on the sub-domain technique.

According to the calculated magnetic vector potential, the magnetic flux density, torque, self- and mutual inductance and back-electromotive force are calculated. The FEM is used to validate the results obtained from the proposed analytic model.

Two-dimensional analytical method is used to obtain the electromagnetic model of FTPMVMs.

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).

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.

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.

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

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.