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"This book presents a comprehensive introduction to design sensitivity analysis theory as applied to electromagnetic systems. It treats the subject in a unified manner, providing numerical methods and design examples. The specific focus is on continuum design sensitivity analysis, which offers significant advantages over discrete design sensitivity methods. Continuum design sensitivity formulas are derived from the material derivative in continuum mechanics and the variational form of the governing equation. Continuum sensitivity analysis is applied to Maxwell equations of electrostatic, magnetostatic and eddy-current systems, and then the sensitivity formulas for each system are derived in a closed form; an integration along the design interface.The book also introduces the recent breakthrough of the topology optimization method, which is accomplished by coupling the level set method and continuum design sensitivity. This topology optimization method enhances the possibility of the global minimum with minimised computational time, and in addition the evolving shapes during the iterative design process are easily captured in the level set equation. Moreover, since the optimization algorithm is transformed into a well-known transient analysis algorithm for differential equations, its numerical implementation becomes very simple and convenient.Despite the complex derivation processes and mathematical expressions, the obtained sensitivity formulas are very straightforward for numerical implementation. This book provides detailed explanation of the background theory and the derivation process, which will help readers understand the design method and will set the foundation for advanced research in the future."

"This book provides the basis of the design of rotating AC machines. The first chapter puts the emphasis on the air gap magnetomotive force (MMF) of Rotating AC machines and the second chapter deals with the formulation of the rotating fields that could be generated considering different technique. The third chapter of this book focuses on the arrangement of the armature winding of fractional-slot concentrated winding permanent magnet synchronous machines, which is achieved considering the star of slots approach.Each topic is explained by case studies that show how to implement the theory into real-world design of DC machines."

"This book discusses the problem of electromagnetic wave excitation in spatial regions with spherical boundaries and the accurate mathematical modeling based on numerical and analytical methods to significantly reduce the time required for developing new antenna devices. It particularly focuses on elements and systems on mobile objects of complex shape that are made of new technological materials. The experimental development of such devices and systems is an extremely time-consuming, lengthy, and expensive process. The book is intended for senior and postgraduate students and researchers working in the fields of radiophysics, radio engineering and antenna design. The authors assume that readers understand the basics of vector and tensor analysis, as well as the general theory of electrodynamics. The original results presented can be directly used in the development of spherical antennas and antenna systems for the mobile objects."

"ABSTRAKPenelitian ini didasarkan pada terjadinya distorsi torsi pada generator magnet permanen saat generator tersebut berputar yang menimbulkan getaran dan derau dan dapat menyebabkan berkurangnya usia mesin, terutama pada penggunaan penggerak langsung. Salah satu cara untuk mengurangi distorsi torsi berupa riak torsi adalah dengan mengubah rancangan konvensional dari struktur stator dan rotor mesin tersebut. Dengan demikian, metode untuk mengurangi riak torsi yang dilakukan dalam penelitian ini adalah dengan memotong ujung/tepi magnet berbentuk busur yang dinamakan magnet bertepi busur atau edge-rounded magnet ERM . Adapun tujuan dari penelitian ini adalah mengembangkan model torsi elektromagnetik dari generator magnet permanen inset dengan ERM sehingga didapatkan riak torsi minimal. Maka diterapkanlah metode tersebut pada generator magnet permanen inset 24 alur 16 kutub dan dibandingkan dengan model dasar tanpa ERM untuk mendapatkan model dengan riak minimal. Perhitungan riak torsi dengan metode torsi rata-rata mendapatkan bahwa riak terendah dicapai oleh generator magnet permanen dengan ERM 2,2 mm yaitu sebesar 2,59 , jauh lebih rendah dibandingkan model dasar 29,87 . Metode least square juga mendapatkan hasil yang sama, model ERM 2,2 mm mempunyai riak terendah sebesar 0,18 dibandingkan model dasar 46,28 . Dengan demikian, modifikasi edge-rounded magnet berhasil memperkecil riak torsi pada generator magnet permanen inset. Dengan riak torsi yang jauh lebih kecil, maka getaran pada generator tersebut juga akan ikut berkurang, walaupun hasil perhitungan mendapatkan bahwa daya keluaran dan efisiensi ERM 2,2 mm hanya sedikit lebih tinggi dibandingkan model dasar. Daya keluaran generator magnet permanen inset dengan ERM 2,2 adalah 1881,487 W, lebih tinggi 8,54 W dari model dasar 1872,948 W , sedangkan efisiensi ERM 2,2 mm adalah 94,07 hanya naik 1,42 dari model dasar 93,65 .

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ABSTRACTThis study is based on the distortion of torque on a permanent magnet generator when the generator is rotating which causes vibration and noise, and can be responsible to reduce the engine life, particularly in the use of direct drive. One alternative to reduce torque distortion in the form of torque ripple is to change the established design of the stator and the rotor structure of the machine. Therefore, the method for reducing the torque ripple carried out in this study is by cutting off an arc shaped magnetic edge called edge rounded magnet ERM . The objective of this study is to develop the model of electromagnetic torque from inset permanent magnet generator with ERM, to obtain the minimum torque ripple. Then applied the method to a permanent magnet generator inset 24 slots 16 poles and compared with the basic model without ERM to get the model with minimal ripple. The computation of torque ripple with the average torque method found that the lowest ripple was carried out by a inset permanent magnet generator with ERM 2.2 mm of 2.59 , much lower than the base model 29.87 . The least square method also got the same result, the ERM 2.2 mm model takes the lowest ripple of 0.18 being comparable to the basic model 46.28 . Therefore, edge rounded magnetic modification strongly minimizes the torque ripple on the inset permanent magnet generator. With a substantial less torque ripple, the vibrations on the generator will similarly decrease, although the calculation results show that the output power and efficiency of ERM 2.2 mm are merely slightly higher than the base model. The output power of permanent magnet generator with ERM 2.2 mm is 1881.487 W, 8.54 W higher than the base model 1872.948 W , while the efficiency of ERM 2.2 mm is 94.07 only up 1.42 from the base model 93.65 ."