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In contrast to conventional permanent magnet machines, integrated magnetic gears exhibit different pole pairs in the stator and the rotor. Consequently, a flux modulation of the air gap magnetic field is necessary for torque transmission, wherefore additional flux modulation poles (FMPs) are used. As the number of FMPs adopts to the pole configuration of the stator and the rotor, arbitrary combinations...
Modular design of wind turbine generators is a promising means to increase the generator availability by reducing downtimes, especially for offshore turbines. With such physically modular designs, the structural support for the generator is an important consideration as it needs to overcome the loss of rigidity in the generator yoke. This makes the structural support design of the generator an important...
Inverter open circuit faults (IOCFs) in AC drives lead to undesired effects and thus, the reconfiguration of the drive to a post-fault operation mode is desirable. In the past some authors have proposed drive topologies and operation strategies to keep the drives operating after IOCFs. However, increased losses and temperatures during these post-fault operation modes lead to a reduced performance...
The brushless doubly-fed machine (BDFM) has been under investigation in its modern forms for 50 years. The reason for this interest is the machine's ability to operate as a brushless variable speed motor or generator through the use of a partially-rated power electronic converter connected to its second stator winding. Interest has increased in the last 20 years because of greater penetration of wind...
A new and improved technique is presented for the measurement of iron loss in motor stators. The most accurate existing technique rotates dummy-test rotors, one for each field strength of interest, inside the stators to be tested and measures the reaction torque on the stators. The new technique uses a wound ‘rotor’ component that does not rotate mechanically but does rotate electrically. Therefore,...
An interior permanent magnet (IPM) machine applied in rail transportation is designed and optimized in this paper. A quasi-octagonal stator iron yoke is adopted in the machine in order to meet the requirement of the installation while the parallel slot structure is also employed due to the arrangement of the performed windings. The method of equivalent stator slot is proposed in this paper to analyze...
High-specific-power electrical machines are a key enabling technology of electric aircraft propulsion. The machine specific power (power-to-weight ratio) is usually constrained by the thermal and mechanical properties of material. To maximize machine specific power, electrical, thermal and mechanical capabilities have to be considered together. In this paper, an efficient multi-physics model of a...
Micro-hydroelectric power plants exhibit low efficiency due to the small size. For this reason, the selection of a high-efficiency electrical machine is particularly important in order to improve the performance of the generation system and to respect the energy policies. In this paper, the performance of different types of machine are computed and compared. In particular an Induction Machine (IM),...
This paper presents a partitioned stator (PS) switched flux permanent magnet (PS-SFPM) synchronous generator (PS-SFPM-SG) and its electromagnetic characteristics under different load conditions. The adopted PS structure enables the PS-SFPM-SG to achieve higher power and torque density due to enlarged slot space for the armature windings by moving PMs to an inner stator. Hence, the space conflict between...
Axial flux machines (AFMs) are used in applications that require high power and torque densities in a pancake-type form factor. There are various types of AFMs based on the configuration of the rotor/stator and magnet orientation. In this paper, a comprehensive analysis and comparison of AFMs with different rotor and stator configurations are presented. Considered topologies are: slotted AFMs with...
This paper proposes a ferrite dual-stator spoke type Vernier permanent magnet machine (DSSVPMM) using a drum rotor for low speed applications. The drum rotor offers supports on both sides of the machine, significantly improving the rotor alignment, the rotor rigidity and stability. The inner stator windings are completely removed and shifted to the outer stator so that the heat produced by the inner...
The air-gap flux in hybrid excitation machine (HEM) can be adjusted flexibly by introducing the auxiliary electric field windings. At present, almost all HEMs employ DC field current to control the flux linked with armature windings, where the bidirectional flux control capability of this structure is not symmetric. In this paper, the reasons of asymmetric problem in HEMs are analyzed, a novel flux...
Recently, flux-switching permanent-magnet (PM) (FSPM) machines have received considerable attentions recently in high reliability applications, due to its high power density, robust structure, and essential sinusoidal back-electromotive-force waveforms [1].
Permanent magnet (PM) machines have found wide applications from automotive to aerospace over the past four decades since they offer several key features, such as high torque density, high efficiency, and excellent dynamic performance [1].
The power generation industry has recently started to invest interest and focus on the single-phase operation of traditional three-phase, wound-field, synchronous generators. This is partially due to a combination of customer requirements and the need to understand the extent of flexibility in their current products. This paper deals with an in-detail analysis of a salient-pole, wound-field, three-phase...
This paper investigates the capability of both permanent magnet synchronous machine (PMSM) and permanent magnet flux switching (PMFS) machine to provide high torque to inertia ratio for applications with demanding response in terms of acceleration and fast dynamic. The PMSM has higher torque density and efficiency among different electrical machines. However, the presence of the permanent magnets...
The brushless doubly-fed induction machine (DFIM) has great potential for wind turbine applications. However, it has not yet been commercialized due to its complicated operating principle. Previously, a computationally efficient FE model has been developed. Some design guidelines for the stator pole-pair combinations and the nested-loop rotors have been gained from the previous work. This paper brings...
Due to the advantages of high efficiency and high torque density, the Permanent Magnet Synchronous Machine (PMSM) has been widely used in direct-drive applications such as all-electric propulsion system. The loss and efficiency of PMSM are the main restriction for performance improvement. This paper focuses on analyzing the influence of structure parameters on the loss and efficiency of PMSM, including...
In this paper the effects of saliency and cross-coupling in a cylindrical wound-rotor synchronous motor are evaluated within the operating region of the direct-axis, quadrature-axis and field excitations. In the calculation of the wound-rotor synchronous motor parameters, a finite element based approach (principle of frozen permeability) is followed to evaluate the inductances and flux linkages of...
Influence of design parameters of a synchronous reluctance machine, such as the pole-pair number, stator and rotor structures and winding configuration, is investigated in this paper. A comprehensive optimization of these parameters is then made to enhance the machine performance. Related design rules are thus concluded. A prototype is designed following the rules, and calculated results by finite...
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