scholarly journals Efficiency Improvement Strategy for Multiple Operating Points in Doubly Fed Magnetic Geared Motor

2020 ◽  
Vol 10 (7) ◽  
pp. 2456 ◽  
Author(s):  
Homin Shin ◽  
Junghwan Chang
Keyword(s):  
Magnetic Flux ◽  
Frequency Control ◽  
Iron Loss ◽  
Operating Efficiency ◽  
Magnetic Flux Density ◽  
Space Harmonic ◽  
Harmonic Components ◽  
Doubly Fed ◽  
Operating Points ◽  
Multiple Operating Points

The doubly fed magnetic geared motor, which has dual AC windings, can be operated with different frequencies in the inner and outer windings. However, the inner and outer windings have different numbers of pole pairs to meet the pole combination derived by the magnetic gearing effect, and hence undesirable space harmonic components of the magnetic flux are produced at the air gaps. These space harmonics affect the iron losses at each core, and the resultant iron loss and efficiency are varied by the frequencies of the inner and outer windings. Thus, in this paper, first, the effect of the space harmonic components of the air gap magnetic flux density in the inner stator, outer stator, and the modulating pieces is separately investigated. In addition, the iron loss characteristics of each ferromagnetic material are presented according to the frequency combinations in the inner and outer windings. Secondly, the iron loss maps and the efficiency maps according to the frequency conditions of the inner and outer windings are drawn, and the causes of the characteristic differences in each map are analyzed. Thirdly, the frequency control sequence and the roles of the inner and outer windings as the armature and field parts are changed, and the analysis of the iron loss map and efficiency map is repeated. Finally, the results in the inner-armature case and the outer-armature case are compared with each other, and the possibility of improving the overall operating efficiency over the multiple operating points by using the individual frequency control and frequency combination selection is proved.

scholarly journals Characteristics Analysis of Doubly Fed Magnetic Geared Motor Considering Winding Frequency Conditions

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2564 ◽  
Author(s):  
Homin Shin ◽  
Junghwan Chang
Keyword(s):  
Frequency Control ◽  
Rotating Magnetic Fields ◽  
Frequency Condition ◽  
Space Harmonic ◽  
Torque Density ◽  
Operating Region ◽  
The Operating Mechanism ◽  
Harmonic Components ◽  
Doubly Fed ◽  
The Individual

The magnetic geared motor, which has improved torque density because of the magnetic gearing effect, has been researched. However, its narrow operating region due to the operating mechanism by the magnetic gearing effect and field flux by the PM is a challenge that needs to be overcome. Whereas, the doubly fed magnetic geared motor (DFMGM) can extend the operating region because of the double stator and double winding structure with the individual frequency control of the current fed to the inner and outer windings. However, two rotating magnetic fields, which are produced by the inner and outer winding flux, exist at the air-gap, and the large numbers of space harmonic components of the modulated flux density are produced at the air-gaps. These space harmonic components, which are produced by the winding MMF, influence not only the back-EMF of the winding but also the performances of the operating torque. Besides, the inner and outer windings affect each other in the back-EMF, and its characteristics appears differently in the inner and outer windings. Thus, in this paper, the structure, operating strategy, and basic characteristics according to the frequency condition in the inner and outer windings are presented.

scholarly journals Development of Si Gradient Steel Sheet with High Saturation Magnetic Flux Density and Low Iron Loss at High Frequency

Materia Japan ◽  
2014 ◽  
Vol 53 (3) ◽  
pp. 110-112 ◽  
Author(s):  
Tatsuhiko Hiratani ◽  
Yoshihiko Oda ◽  
Misao Namikawa ◽  
Shouji Kasai ◽  
Hironori Ninomiya
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
High Frequency ◽  
Steel Sheet ◽  
Iron Loss ◽  
Magnetic Flux Density ◽  
High Saturation

scholarly journals Analysis and identification of influential phenomena on iron losses in embedded permanent magnet synchronous machine

2017 ◽  
Vol 68 (1) ◽  
Author(s):  
Mitja Breznik ◽  
Viktor Goričan ◽  
Anton Hamler ◽  
Selma Čorović ◽  
Damijan Miljavec
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Iron Loss ◽  
Magnetic Flux Density ◽  
Iron Losses ◽  
Ipm Machine ◽  
Element Method

AbstractThis paper presents magnetic flux density behaviour in laminated electrical sheets which affects the results and precision of iron losses calculation in imbedded permanent magnet (IPM) machine. Objective of the research was to analyse all the influential phenomena that were identified through iron loss models analysis, finite element method simulations and iron loss measurements. The presence of phenomena such as harmonic content and rotational magnetic fields are confirmed with finite element method analysis of concentrated and distributed winding IPM machine. A significant magnetic flux density ripple in the rotor of concentrated winding IPM machine in comparison to distributed winding IPM machine is revealed and analysed. Behaviour that affects iron loss in the rotor of synchronous machines in the absence of first order harmonic is analysed. The DC level added to alternating magnetic flux density was used in experiment to mimic magnetic behaviour on the rotor of IPM machine and further to calculate iron losses.

Calculation and validation of iron loss in laminated core of power and distribution transformers

2013 ◽  
Vol 33 (1/2) ◽  
pp. 137-146 ◽  
Author(s):  
Xiaoyan Wang ◽  
Zhiguang Cheng ◽  
Li Lin ◽  
Jianmin Wang
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Core Loss ◽  
Iron Loss ◽  
Magnetic Flux Density ◽  
Content Type ◽  
The Core ◽  
Distribution Transformers ◽  
The Impact ◽  
Transformer Core

Purpose – The purpose of this paper is to present a simple method to analyze the iron loss in the laminated core of power and distribution transformers. Design/methodology/approach – This paper presents a practical method to calculate the no-load loss in the transformer cores. Considering the non-uniformity of the magnetic flux density in the corner areas of the Epstein frames will affect the measurement precision of the Wt-B curves then further affect the core loss calculation in FEM, a dual-Epstein frame method is used to measure the Wt-B curves with the Epstein sample stripes cutting by different angles to the rolling direction. A 2D FEM that considers the type of joints of the core and eddy current effect in the laminations is used to analyze the core loss with multi-angle Wt-B curves. Findings – The impact of lamination thickness, size of gaps and type of joint of the core are considered. Considering the no-load testing conditions, harmonics in the exciting currents are taken into account. Originality/value – Harmonic wave of magnetic flux density in the transformer core is calculated and the core loss in the joint region is calculated by the loss curve measured with dual-Epstein frame. It makes the calculation result of transformer core loss more exactly.

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