Browsing by Author "Ergun B.E."

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    Rare-earth Magnet Free Flux-switching Generator for Wind Turbines in Micro-grids: A Review
    (China Electrotechnical Society, 2024) Ozmen T.; Ergun B.E.; Gulbahce M.O.; Onat N.
    In traditional electricity generation plants, large powerful synchronous, induction, and direct current generators were used. With the proliferation of microgrids focused on electricity generation from renewable energy sources in today’s power grids, studies have been conducted on different types of generators. Instead of the traditional generator architecture, generators with brushless structures, particularly those utilizing magnets for excitation, have found broad applications. Flux-switching generators (FSGs) are innovative types owing to their robust structure, active stator design, and high power density capabilities. However, designs have typically relied on rare-earth element magnets. Rare-earth magnets possess negative characteristics such as price uncertainty, the potential risk of scarcity in the future, and limited geographical production, leading to research on FSGs that do not depend on rare-earth magnets. This study comprehensively examines FSGs that do not use rare-earth element magnets. The study delves into the usage areas, operational mechanisms, structural diversities, and counterparts in the literature of these generators. © 2024 CES.
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    Comparison of Different Axial-Flux Induction Generator Topologies in Variable Speed Wind Turbine Applications; [Deǧişken Hizli Rüzgâr Türbini Uygulamalari İçin Farkli Eksenel Akili Asenkron Generatör Mimarilerinin Karşilaştirilmasi]
    (Institute of Electrical and Electronics Engineers Inc., 2024) Ergun B.E.; Ozmen T.; Gulbahce M.O.
    Wind energy has inevitably become widespread due to the increasing world population, sustainability problems, and the green energy standards that are increasingly coming to the forefront. Axial-flux induction generators (AFIG) are one of the significant generator topologies that can meet the expectations from wind energy systems. It is possible to derive various AFIG topologies by using different stator and rotor combinations. Each topology gains significance according to the requirements of the application. In this paper, 8 kW, 400V/50 Hz single stator-single rotor (SSSR) and double stator-single rotor (DSSR) topologies have been examined, and both analytical and finite element analysis results have been compared through the equivalent circuit design approach for these topologies. It has been demonstrated, both by finite element analyses and the outputs of the developed algorithm, that the DSSR-AFIG architecture outperforms the SSSR-AFIG in terms of both power density and efficiency. © 2024 IEEE.
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    The Effects of Rotor Delta and Embrace Parameters on the Performance of Flux-Switching Generator; [Rotor Kutup Eǧimi ve Yay-Kutup Adimi Orani Parametrelerinin Aki-Anahtarlamali Generatörün Başarimina Etkileri]
    (Institute of Electrical and Electronics Engineers Inc., 2024) Isikelekoglu T.; Ozmen T.; Ergun B.E.; Onat N.; Gulbahce M.O.
    One of the types of generators used in variable-speed wind turbine applications in microgrids is the flux-switching generator. Due to the double-salient structure of flux-switching generators, torque ripples and harmonic content are high. In addition, the magnetic flux density in the stator and rotor teeth is elevated. To overcome these issues, improvements can be made in the machine's design parameters. In this study, the effects of rotor pole skew (delta) and coil-pole pitch ratio (embrace) parameters on the machine-s output values for a 1200 min-1, 200 Hz, and 260W design were examined. It was observed that changes in the pole skew and coil-pole pitch ratio parameters affect torque, flux linkage, and induced voltage values, and can reduce magnetic stresses © 2024 IEEE.
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    The Effects of the Multi-Slice Skewing Applied to the Rotor on the Performance of a Flux Switching Generator; [Aki Anahtarlamali Generatörde Rotora Uygulanan Çok Katmanli Kaykinin Makina Başarimina Etkileri]
    (Institute of Electrical and Electronics Engineers Inc., 2024) Durmaz S.T.; Isikelekoglu T.; Ozmen T.; Ergun B.E.; Onat N.; Gulbahce M.O.
    Flux-switching generators are one of the types of generators commonly used in wind turbine applications, particularly in microgrids. The torque ripple and harmonic content of flux-switching generators are significantly high due to the salient pole structure of the stator and rotor teeth. In this study, a multi-layer skewing method was applied to the rotor of a 260 W flux-switching generator, and its effects on the generator's average torque, torque ripple, and efficiency parameters were analyzed. The obtained results indicated that, due to the dominance of the second harmonic, the skewing angle did not have a significant effect on the output parameters. Furthermore, the influence of the number of layers on the generator's output parameters and production difficulty was examined. © 2024 IEEE.