Basikal elektrik menyediakan system pengangkutan tempatan yang selesa dan menjadi sangat popular pada masa sekarang terutamanya untuk kegunaan jarak dekat. Selaras dengan penggunaan magnet kekal di dalam basikal elektrik, “cogging torque” perlu di ambil kira. Ini kerana kewujudan “cogging torque” yang tinggi akan mengakibatkan getaran mekanikal dan bunyi bising pada motor. Keadaan yang tidak diingini tersebut muncul dengan ketara pada mesin magnet kekal. Justeru, mengurangkan “cogging torque” menjadi objektif utama di dalam projek ini. Sebelum mengurangkan “cogging torque”, ciri-ciri dan teknik-teknik untuk mengurangkan “cogging torque” perlu dikenalpasti terlebih dahulu. Selepas memahami “cogging torque”, empat jenis motor yang berbeza akan direkabentuk iaitu motor magnet kekal jenis rotor di luar “6 slot 4 pole”, “6 slot 8 pole”, “9 slot 8 pole”, dan motor “9 slot 10 pole”. Pengurangan “cogging torque” akan dilakukan secara simulasi menggunakan perisian Opera-2d. Model-model bagi motor tersebut akan dibina menggunakan perisian AutoCAD sebelum ianya diimport ke perisian Opera-2d untuk tujuan simulasi. Terdapat empat teknik yang akan digunakan di dalam projek ini iaitu teknik condongkan pemegun, teknik pegubahsuaian sudut magnet, teknik pemdwibahagian pemegun, dan teknik menggunakan bentuk magnet. Setiap teknik tersebut mempunyai kebaikan dan keburukan yang tersendiri. Oleh itu, teknik-teknik tersebut akan dibandingkan untuk menentukan teknik yang paling sesuai digunakan pada basikal elektrik.
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Electric bicycles provides convenient local transportation and become very popular nowadays especially for short distance usage. As the permanent magnet motors are used in electrical bicycle, the cogging torque must be taken account. This is because the existence of high cogging torque will result in mechanical vibration and noise in the motor. These are undesired problems that arise apparently in permanent magnet machine. Thus, minimizing cogging torque had been the main objective in this project. Before the cogging torque can be minimize, the characteristics and techniques to minimize cogging torque need to be studied first. After understanding cogging torque, four different motors will be designs which are 6 slot 4 pole, 6 slot 8 pole, 9 slot 8 pole, and 9 slot 10 pole external rotor permanent magnet motors. The minimizing of cogging torque will be computed using Opera-2d software which is by simulation. These motors will be modeled using AutoCAD software and then imported into Opera-2d for simulation purpose. There are four techniques will be used in this project which are skewing stator technique, optimize magnet pole arc technique, bifurcated stator teeth technique, and magnet shaping technique. Each of these techniques has its own advantages and disadvantages as well. Thus, all of these techniques will be compared to find the most suitable technique that can be use for electric bicycle.
Electric bicycles provides convenient local transportation and become very popular nowadays especially for short distance usage. As the permanent magnet motors are used in electrical bicycle, the cogging torque; cogging torque will be computed using Opera-2d software which is by simulation.
Minimization of cogging torque in external rotor permanent magnet motors for electric bicycle_Mohamad Razif Bin Zainudin_E3_2010_875002997_00003079898_NI