• Title/Summary/Keyword: High Efficiency Design

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Optimal Design of Soft-Switching Cell for High Efficiency and High Power Density for HDC of FCEVs (FCEV용 HDC 고효율 운전을 위한 소프트 스위칭 셀 최적 설계 방안)

  • Kim, So-Young;Noh, Tae-Won;Lee, Jaehyung;Ahn, Jung-Hoon;Lee, Byoung Kuk
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.3
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    • pp.217-224
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    • 2018
  • In this study, the optimal design methods of soft-switching cell for high-voltage DC-DC converter (HDC) of fuel cell electric vehicles (FCEVs) is proposed for high efficiency and high power density. The appropriate soft-switching cell for FCEVs is chosen by analyzing the losses of HDC which adopts soft-switching cell. The proposed optimal design methods for the soft-switching cell are divided into two purposes which are improvement of efficiency and power density. Two kinds of design methods enable to improve fuel efficiency and cost, respectively. The proposed design methods are validated with the experimental results based on the specification and hardware used in actual FCEVs.

Design Principles and Validation of a Human-sized Quadruped Robot Leg for High Energy Efficiency (에너지 효율적인 인간 크기 4족 보행 로봇의 설계와 검증)

  • Yeom, Hoyeon;Ba, Dang Xuan;Bae, Joonbum
    • The Journal of Korea Robotics Society
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    • v.13 no.2
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    • pp.86-91
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    • 2018
  • This paper presents about design efforts of a human-sized quadruped robot leg for high energy efficiency, and verifications. One of the representative index of the energy efficiency is the Cost of Transport (COT), but increased in the energy or work done is not calculated in COT. In this reason, the input to the output energy efficiency should be also considered as a very important term. By designing the robot with customized motor housing, small rotational inertia, and low gear ratio to reduce friction, high energy efficiency was achieved. Squatting motion of one leg was performed and simulation results were compared to the experimental results for validation. The developed 50 kg robot can lift the weight up to 200 kg, and during squatting, it showed high energy efficiency. The robot showed 71% input to output energy efficiency in positive work. Peak current during squatting only appears to be 0.3 A.

Optimization of Vane Diffuser in a Mixed-Flow Pump for High Efficiency Design

  • Kim, Jin-Hyuk;Kim, Kwang-Yong
    • International Journal of Fluid Machinery and Systems
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    • v.4 no.1
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    • pp.172-178
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    • 2011
  • This paper presents an optimization procedure for high-efficiency design of a mixed-flow pump. Optimization techniques based on a weighted-average surrogate model are used to optimize a vane diffuser of a mixed-flow pump. Validation of the numerical results is performed through experimental data for head, power and efficiency. Three-level full factorial design is used to generate nine design points within the design space. Three-dimensional Reynoldsaveraged Navier-Stokes equations with the shear stress transport turbulence model are discretized by using finite volume approximation and solved on hexahedral grids to evaluate the efficiency as the objective function. In order to reduce pressure loss in the vane diffuser, two variables defining the straight vane length ratio and the diffusion area ratio are selected as design variables in the present optimization. As the results of the design optimization, the efficiency at the design flow coefficient is improved by 7.05% and the off-design efficiencies are also improved in comparison with the reference design.

Design of High Quality Regulator with High Efficiency Based on Half-Bridge Topology (하프 브릿지 컨버터를 기반으로 한 고효율을 갖는 고역률 정류기의 설계)

  • 이준영;문건우;정영석;윤명중
    • Proceedings of the KIPE Conference
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    • 1997.07a
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    • pp.400-409
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    • 1997
  • Design of single stage AC/DC converter with high power factor and high efficiency based on half-bridge topology for low power application is proposed. To obtain design equations, modelling and detailed analysis are performed. The proposed converter gives and power factor and high efficiency by employing aynchronous rectifiers. To verify the performances of the proposed converter 90W-converter has been designed. This prototype converter meets IEC555-2 requirements with near unity power factor.

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Study of the Flow in Centrifugal Compressor

  • Xu, Cheng;Amano, Ryoichi Samuel
    • International Journal of Fluid Machinery and Systems
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    • v.3 no.3
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    • pp.260-270
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    • 2010
  • Reducing the losses of the tip clearance flow is one of the keys in an unshrouded centrifugal compressor design and development because tip clearances are large in relation to the span of the blades and also centrifugal compressors produce a sufficiently large pressure rise in single stage. This problem is more acute for a low flow high-pressure ratio impeller design. The large tip clearance would cause flow separations, and as a result it would drop both the efficiency and surge margin. Thus a design of a high efficiency and wide operation range low flow coefficient centrifugal compressor is a great challenge. This paper describes a recent development of high efficiency and wide surge margin low flow coefficient centrifugal compressor. A viscous turbomachinery optimal design method developed by the authors for axial flow machine was further extended and used in the centrifugal compressor design. The compressor has three main parts: impeller, a low solidity diffuser and volute. The tip clearance is under a special consideration in this design to allow impeller insensitiveness to the clearance. A patented three-dimensional low solidity diffuser design method is used and applied to this design. The compressor test results demonstrated to be successful to extend the low solidity diffusers to high-pressure ratio compressor. The compressor stage performance showed the total to static efficiency of the compressor being about 85% and stability range over 35%. The test results are in good agreement with the design.

Analysis and Design of Function Decoupling High Voltage Gain DC/DC Converter

  • Wei, Yuqi;Luo, Quanming;Lv, Xingyu;Sun, Pengju;Du, Xiong
    • Journal of Power Electronics
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    • v.19 no.2
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    • pp.380-393
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    • 2019
  • Traditional boost converters have difficulty realizing high efficiency and high voltage gain conversion due to 1) extremely large duty cycles, 2) high voltage and current stresses on devices, and 3) low conversion efficiency. Therefore, a function decoupling high voltage gain DC/DC converter composed of a DC transformer (DCX) and an auxiliary converter is proposed. The role of DCX is to realize fixed gain conversion with high efficiency, whereas the role of the auxiliary converter is to regulate the output voltage. In this study, different forms of combined high voltage gain converters are compared and analyzed, and a structure is selected for the function decoupling high voltage gain converter. Then, topologies and control strategies for the DCX and auxiliary converter are discussed. On the basis of the discussion, an optimal design method for circuit parameters is proposed, and design procedures for the DCX are described in detail. Finally, a 400 W experimental prototype based on the proposed optimal design method is built to verify the accuracy of the theoretical analysis. The measured maximum conversion efficiency at rated power is 95.56%.

Design Methodology of 500 W Wireless Power Transfer Converter for High Power Transfer Efficiency (500 W 급 무선전력전송 컨버터의 고효율 설계 방법)

  • Kim, Mina;Park, Hwapyeong;Jung, Jee-Hoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.4
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    • pp.356-363
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    • 2016
  • The design methodology of an adequate input voltage and magnetizing inductance to minimize reactive power is suggested to design a wireless power transfer (WPT) converter for high-power transfer efficiency. To increase the magnetizing inductance, the turn number of the WPT coil is increased, thus causing high parasitic resistance in the WPT coil. Moreover, the high coil resistance produces high conduction loss in the transfer and receive coils. Therefore, the analysis of conduction loss is used in the design of the WPT coil and the operating point of the WPT converter. To verify the proposed design methodology, the mathematical analysis of the conduction loss is presented by experimental results.

A Study on the Development of High Efficiency Anti-Vibration Boring Bar (고능률 방진 보링바 개발에 관한 연구)

  • 최춘규;이우영;최성주;이동주
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.109-112
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    • 1995
  • This paper analyzes high efficiency anti-vibration boring bars which increase stability against chatter vibration in boring operations. Structural analysis and mathematical modeling with considering dynamic properties for three types of existing boring bars are performed to search for optimal design parameters. The purpose of this paper is to find out design parameters for high efficiency anti-vibration boring bar.

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A Study on Design of Linear Motor for Maglev for High Efficiency (자기부상열차 추진용 리니어모터 효율향상 설계연구)

  • Kim, Youn-Hyun;Kim, Ki-Chan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.4
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    • pp.561-566
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    • 2016
  • In this paper, effective design method of linear induction motor(LIM) for Maglev is proposed in order to maximize system efficiency of Maglev. For the high system efficiency of Maglev, it is important to minimize weight of traction motor. Light weight design by changing materials of core and winding is conducted without changing volume of LIM. For the silicon steel core of primary part for magnetic flux path, iron-cobalt alloy steel with high magnetic saturation characteristic compared to silicon steel is suggested. Moreover, aluminium winding with light weight instead of copper winding is wounded in the widen slot area due to the high magnetic saturation level. For the verification of performance of proposed model, the characteristics are analyzed by using finite element method(FEM).

Optimal Design Methodology of Zero-Voltage-Switching Full-Bridge Pulse Width Modulated Converter for Server Power Supplies Based on Self-driven Synchronous Rectifier Performance

  • Cetin, Sevilay
    • Journal of Power Electronics
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    • v.16 no.1
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    • pp.121-132
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    • 2016
  • In this paper, high-efficiency design methodology of a zero-voltage-switching full-bridge (ZVS-FB) pulse width modulation (PWM) converter for server-computer power supply is discussed based on self-driven synchronous rectifier (SR) performance. The design approach focuses on rectifier conduction loss on the secondary side because of high output current application. Various-number parallel-connected SRs are evaluated to reduce high conduction loss. For this approach, the reliability of gate control signals produced from a self-driver is analyzed in detail to determine whether the converter achieves high efficiency. A laboratory prototype that operates at 80 kHz and rated 1 kW/12 V is built for various-number parallel combination of SRs to verify the proposed theoretical analysis and evaluations. Measurement results show that the best efficiency of the converter is 95.16%.