New block diagrams using vector signals in the general frame of reference for AC motors with stator core losses

2001 ◽  
Vol 138 (2) ◽  
pp. 59-70 ◽  
Author(s):  
Shinji Shinnaka
Keyword(s):  
Frame Of Reference ◽  
Stator Core ◽  
General Frame ◽  
Ac Motors ◽  
Core Losses ◽  
Vector Signals

Time-stepping finite element analysis on the influence of rotational flux on local core losses of AC electrical machines

2013 ◽  
Vol 33 (1/2) ◽  
pp. 126-136
Author(s):  
Zhao Haisen ◽  
Liu Xiaofang ◽  
Cui Xueshen ◽  
Luo Yingli
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Machines ◽  
Stator Core ◽  
Element Analysis ◽  
Content Type ◽  
Time Stepping ◽  
Harmonic Field ◽  
Core Losses ◽  
Element Method

Purpose – The purpose of the paper is to study the influence of rotational flux on local core losses of the motors, which is difficult to distinguish the iron losses caused by rotational flux in certain electric machines through experiment. Therefore, time-stepping finite element method (T-S FEM) is used to consider the rotational flux and to predict the local core losses. Design/methodology/approach – Time-stepping finite element method. Findings – It is found that, in stator side, rotational flux mainly exists in tooth root and yoke area near the bottom of stator slot, those area is about 45 percent of total stator core area; in rotor side, due to slot harmonic field, the rotational flux mainly exists in the tip of tooth. Originality/value – Through analyzing the magnetization characteristics at different positions in stator and rotor cores by T-S FEM, the influence of rotational flux on local core losses of AC electric machines is studied.

The Making of a Physician — General Statement of Ideas and Problems

1955 ◽  
Vol 14 (4) ◽  
pp. 21-25 ◽  
Author(s):  
Everett Hughes
Keyword(s):  
Medical School ◽  
Frame Of Reference ◽  
Group Interview ◽  
General Statement ◽  
Social Scientists ◽  
General Frame ◽  
Medical Educators

Social scientists are being called upon more and more to study training for the various professions and to consult with those who make policy with reference to it. The following pages suggest a general frame of reference for such study. They were written for several people, both medical educators and social scientists, who were thinking of embarking on a modest study tracing the course of students through the maze of a particular medical school. There resulted a daylong discussion which was of great value in planning the study. It was more like a prolonged group interview than a formal discussion. While the ideas refer specifically to medicine, they implicitly refer to other professions as well.

A Model- Based Detection Method for Stator Core Fault in Induction Motors

2012 ◽  
Vol 588-589 ◽  
pp. 1068-1071
Author(s):  
Xu Hong Wang ◽  
Hui Zhi Liu
Keyword(s):  
Detection Method ◽  
Equivalent Circuits ◽  
Stator Core ◽  
Core Losses ◽  
Zero Sequence ◽  
On Line ◽  
Coordinate Model ◽  
Stator Fault ◽  
Negative Sequence Current ◽  
Asymmetrically Distributed

An on-line method to detect induction motor stator core fault by stator negative sequence current is proposed in this paper. New equivalent circuits including the positive, negative and zero sequence equivalent circuits are is obtained by the existing abc coordinate model. In the circuits, the stator core losses is increased and asymmetrically distributed among the three phases when a stator fault happens. Experiment results prove the effectiveness of this method.

A Discussion of Helping Theory, Christian Beliefs, and Persons with Disabilities

1998 ◽  
Vol 29 (3) ◽  
pp. 25-30 ◽  
Author(s):  
E. Keith Byrd
Keyword(s):  
Spiritual Healing ◽  
Chronic Illnesses ◽  
Physical Problem ◽  
Frame Of Reference ◽  
Persons With Disabilities ◽  
General Frame ◽  
Professional Worker ◽  
Potential Source ◽  
The Impact ◽  
Christian Beliefs

Helping theories are discussed within the general frame of reference of Christian beliefs and the impact they may have on the spiritual healing of persons with disabilities or chronic illnesses. Each helping theory is summarized, then related to generally accepted ideas about Christian beliefs and their relationship to healing and rehabilitation. Spirituality can be seen as a potential source of help for persons who experience a chronic physical problem if at least minimally nurtured by the professional worker in rehabilitation.

scholarly journals Modified Slot Opening for Reducing Shaft-to-Frame Voltage of AC Motors

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 760 ◽  
Author(s):  
Manje Yea ◽  
Ki Jin Han
Keyword(s):  
Finite Element Analysis ◽  
Electromagnetic Interference ◽  
Electrical Machines ◽  
Stator Core ◽  
Element Analysis ◽  
Ac Motors ◽  
Reference Design ◽  
Slot Opening ◽  
Bearing Current ◽  
Opening Width

This paper presents a method to reduce the winding-to-rotor capacitance of electrical machines for the purpose of suppressing shaft-to-frame voltage, which causes reliability issues, such as electromagnetic interference (EMI) and bearing current. The proposed method is based on the modification of slot opening shape of the stator core, including the variation of slot opening width and the use of oblique slot opening. For the verification of the suggested method, six different slot opening shapes, including a reference design, are analyzed and compared using finite element analysis, and the results show that the proposed method can reduce the shaft-to-frame voltage by 98%, compared to the reference design.

scholarly journals Analysis of Core Loss of Permanent Magnet Synchronous Machine for Vehicle Applications under Different Operating Conditions

2020 ◽  
Vol 10 (20) ◽  
pp. 7232
Author(s):  
Guohui Yang ◽  
Shuo Zhang ◽  
Chengning Zhang
Keyword(s):  
Permanent Magnet ◽  
Pulse Width Modulation ◽  
High Efficiency ◽  
Core Loss ◽  
Operating Conditions ◽  
Permanent Magnet Synchronous Machines ◽  
Stator Core ◽  
Core Losses ◽  
Novel Method ◽  
Maximum Torque Per Ampere

Permanent magnet synchronous machines (PMSMs) are widely used in electric vehicles due to their high power density, high efficiency, etc. Core losses account for a significant component of the total loss in PMSMs. Therefore, it is necessary to carefully consider it when designing PMSMs according to actual scientific research project applications. This paper extracts the characteristic operating points of the PMSMs under different operating conditions at different speeds. Then a harmonic analysis of air-gap flux density, phase current, core loss was completed, and detailed comparative analysis was performed. A novel method for comprehensively analyzing the stator core loss of PMSMs for vehicles is proposed, which reveals the law of the core loss of the PMSM under Maximum-Torque-Per-Ampere (MTPA) and Space Vector Pulse Width Modulation (SVPWM). The method was verified by a prototype experiment where the actual core loss of PMSMs was measured to verify the correctness of the method. This research provides a reference for accurately predicting core loss during the forward design of PMSMs and completing core loss evaluation for existing PMSMs.

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