電感磁性材料為一個基礎而傳統的材料，在所有電子產品的電子線路中都包含了電感，它的形狀和材料特性非常寛廣，依使用的電路範圍和應用領域而有所不同。電感成品最重要的材料之一是鐵芯，電芯這個產業中雖然是一個技術門檻不高的產業，但它却是一個不易容取代和不可缺少的產業。 台灣電子產業外移的變遷史中，電感傳統產業最先因成本和環境因素外移，但外移之後因技術門檻不高使得不斷有競爭者進入市場，整個產業毛利下降，進入完全競爭的經濟市場，陷入一個紅海領域。 如何透過有系統的整理和分析，從價格領導到差異化和聚焦策略，將黑手產業加值--電感磁性材料產業未來經營策略之個案研究。 / Inductance is one of the most essential components in electronic circuit since all of the electronic products contain it. According to different kinds of applications and the required range of impedance in electronic circuit, they vary from their shapes and properties of materials. However, inductances are basically composed of coils and cores. Cores (magnetic material) are tremendously important because they can easily affect the properties of inductances. Admittedly, manufacturing cores is not complicated in technique since it is easy to understand the principle operation of inductances, but it is still an irreplaceable and indispensible industry. Moreover, the cost of manufacturing was rapidly rising in 80/90’s due to higher and higher price of labor and the shortage of manpower in Taiwan. Gradually, traditional industry moved out to low-cost area such as China, Indonesia and Vietnam. This industry becomes more and more competitive because products are not easy to be differentiated and technical barriers in producing are easily overcome. Therefore, how to cost down and manage the process of manufacturing are the major issues for any firms in the industry. The goal of the study is to seek the appropriate strategy for the business growth in manufacturing inductances. Based on our analysis, the considered strategies include focusing and differentiating products (maximizing the additive value of products), instead of price reducing.

While the process that converts implosion into explosion in core collapse supernovae is poorly understood, their observed asphericity provides new constraints on the physics of these events. Since pulsars are rotating and magnetized neutron stars, there is no doubt that rotation and magnetic fields are inherent to the exploding engine. We have shown that magnetic field amplification is an inevitable by-product of the differential rotation that accompanies core-collapse. We performed 1D core-collapse simulations of rotating iron cores with various rotational profiles and velocities. We found that differential rotation was a generic feature of rotating iron core collapse. As a result, the magnetorotational instability (MRI) generates magnetic fields of order 10¹⁵⁻¹⁷ G in a few tens of milliseconds where the negative shear is the strongest. Although magnetic fields of order 10¹⁵⁻¹⁷ G are very strong, they are not strong enough to modify the equation of state of degenerate electron gas near the proto-neutron star. The corresponding MHD luminosity available is ~10⁵² erg s⁻¹, which can modify the explosion dynamics if the power is sustained for a fraction of a second. When rotational effects are included, we found that there is a critical iron core rotation rate that gives the most rapidly rotating proto-neutron star, faster than which the rotational velocity of the proto-neutron star decreases due to centrifugal support. This non-monotonic behavior of post-collapse core rotation suggests that the progenitor of the most rapidly rotating proto-neutron star is not the most rapidly rotating iron core, but that those iron cores with nearly the critical initial rotation rate may produce the maximum proto-neutron star rotation, the strongest magnetic fields, and the most robust supernova explosions. Even small rotation may induce non-axisymmetric instabilities, which drive magneto-acoustic flux in to the mantle, transporting enegy out of the proto-neutron star to the region near the stalled shock. Further implications for rotation and magnetic fields, pulsars and magnetars, and jet formation mechanisms are discussed. / text

In this research work detailed parallel and series equivalent circuits of a gapped iron-core shunt reactor with discretely distributed gaps are derived. The validity of the recommended equivalent circuits is verified by Finite Element Analysis and laboratory tests. Effects of fringing flux and discretely distributed gaps on inductance parameters and reactor losses are also investigated. Moving Strip Method for discretely distributed gapped shunt reactors is recommended. Two design procedures for shunt reactor with discretely distributed gaps are developed within the scope of this thesis. A simple and practical design approach is also developed which does not need any Finite Element Analysis software. This practical method is very useful for design engineers and researchers. The results of practical design approach are shown to be in good agreement with Finite Element Analysis and experimental work.

The master’s thesis introduces various types of electric motors. Overall, it is divided into 6 chapters, which the first deals with special type of electric motors, namely: permanent magnet DC motor with coreless winding, piezoelectric motor and three phase induction motor with solid rotor. For all of these motors are introduced principles, types, advantages, disadvantages and applications. The second part of thesis deals with perspective types of motors, namely: single phase induction motor and reluctance motor. For all of these motors are introduced principles, types, advantages, disadvantages and applications. The third chapter deals with analysis parameters of single phase induction motor. The analysis is performed on a borrowed motor from ATAS company by measurement and verification using simulation program Ansys Maxwell. The fourth part discusses the possibilities of increasing the effectiveness of borrowed electric motor. The following is chapter five, which deals with increasing the efficiency of the motor by changing metal sheets. Results are verified by simulations with Ansys Maxwell and measurements on sample of electric motor. The last part presents electric motor design with new selected electric sheets with lower specific losses, but also with lower magnetic induction.

The first part of this thesis deals with the study of linear motors. The introduction of the thesis deals with the brief description of the linear motor, including its accessories. This part explains principle of linear motors, their general advantages and disadvantages. The next section contains an overview and division of the currently used linear motors. The second part deals with the theoretical description of forms of heat transfer. The third part of the thesis deals with the design of an equivalent thermal circuit model of a linear iron-core linear motor with permanent magnet. Hereafter, the proposed design will be used to calculate the temperatures of the individual motor units. The temperatures are later compared with the results obtained with finite element method.

The master's thesis deals and introduces a single-phase inductions machines, the principle of operation, types of design and operating conditions. This thesis includes analysis of individual losses in the machine and reduce the possibility of different ways. After a theoretical proposal for reducing losses are measured by mass-produced single-phase induction machine. Further machine modifications proposed for reducing losses in the stator windings and designed a prototype machine with the adjustment of the magnetic circuit to reduce iron losses made by ATAS elektromotory Nachod a.s. The results are supplemented by a simulation using software Maxwell RMxprt and finite element method (FEM). Finally, they are compared to each machines modifications mainly in terms of energy consumption.

The aim of this master´s thesis is to analyze core losses of a small induction motor. Analyzed values are obtained from laboratory measurements, software analysis and 2D finite element method simulation. The theoretical part of this thesis consists of two parts. The analysis of the higher spatial harmonics presents in the induction motor and the analysis of core losses of the motor. Practical part consists of laboratory measurements according to ČSN. Measured values are used to calculate individual losses. The next part consists of creating a model for software analysis (Maxwell RMxprt). The generated model is converted into a 2D simulation environment (Maxwell 2D), where it is adapted to obtain values from the examined parts (rotor and stator teeth and rotor cage). Results of simulations at different loads are compared and analyzed from the point of view of higher harmonics.