• Title/Summary/Keyword: rotational inertia

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The Implementation of the Speed Measurement Board for the Reaction Wheel on the LEO Satellite using the T, M-Method (T-방식과 M-방식을 이용한 저궤도위성용 반작용 휠의 속도측정보드 설계)

  • Lee, Jae-Nyeung;Park, Sung-Hun;Heu, Su-Jin;Lee, Yun-Ki
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.9
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    • pp.827-832
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    • 2012
  • In this paper, we will design the speed measurement board of LEO Satellite's reaction wheel which has two speed measuring methods as M-Method type and T-Method type. therefore we can use the advantage of two methods. and we will verify the availability of design on the on-board computer at the real LEO Satellite(KOMPSAT-3). In the reaction wheels satellite that can change the satellite's attitude is one of the leading drivers by the rotational inertia of the motor will perform attitude control. Reaction methods for detecting wheel rotation speed generated during a certain period T internal reaction wheel tacho pulse counting M-Method to detect wheel speed and wheel tacho pulses are generated by measuring the time between the detection rate can be divided into T-Method. M-method is simple to implement and benefit measurement time is constant, but slow fall in the velocity measurement accuracy is a disadvantage. In contrast, the time between tacho pulses to measure the T-Method to measure the precise speed at low speed and to measure the time delay is small, has the advantage. However, this method also in the actual implementation and the complexity of the operation at different speeds depending on the speed of operation has the disadvantage.

A Study on the Determination of Slot's Number of Rotor to Reduce Noise and Vibration and Design the 3-Phase Induction Motor Considering Kinetic Energy in Flywheel Energy Storage System (운동 에너지를 고려한 Flywheel Energy Storage System 설계와 진동 저감을 위한 3상 유도기의 슬롯수 산정에 관한 연구)

  • Ryu, Jae Ho;Kim, Hui Min;Lee, Chee Woo;Park, Gwan Soo;Jeong, Dong Wook
    • Journal of the Korean Magnetics Society
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    • v.27 no.1
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    • pp.1-8
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    • 2017
  • Flywheel Energy Storage System (FESS) is composed by flywheel generating rotating potential energy and motor/generator set charging and discharging electric potential energy. The flywheel and motor/generator is connected by rotating shaft. And torque characteristics of motor/generator part can influence charging and mechanical traits of FESS. This paper analyze about motor/generator design method of 5 [kWh] FESS and torque ripple, harmonic effects by change of slots. At First, this paper proposes a method to estimate the flywheel size and the rotor size of the motor from the the rotational kinetic energy by inertia of FESS. The number of induction motor rotor slots for torque ripple reduction in the high speed operation region is selected. This paper performs to reduce the noise and vibration of the flywheel composed of coaxial with motor/generator and flywheel and realize the high efficiency.