• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.187-187
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• 2010

풍력을 이용한 풍력발전기의 전력변환 시스템을 연구개발하기 위해서는 바람의 특성을 실내에서 구현할 수 있는 모의시험장치인 시뮬레이터가 요구된다. 모의시험장치는 바람을 받아 회전하는 블레이드 대신 풍속 값을 입력하여 전동기가 발전기에 토오크(torque)를 공급하게 된다. POSTECH 풍력에너지연구소는 2003년 750kW급 KBP-750D 풍력발전기용 모의시험장치에 이어, 2007년 2MW Gearless형 풍력발전기(KBP-2000M)의 400:1 축소모델인 5.83kW 모의시험 장치를 제작 완료하였다. (주)플라스포사는 모의시험장치를 이용하여 고효율의 전력변환장치 설계와 인버터 시스템 제어 알고리즘을 개발하였고, (주)유니슨은 2MW 풍력발전기용 통합연동제어 시스템을 제작 완료하여 2009년부터 대관령 실증단지에 초도품을 설치하고 실증운영 중에 있다. 본 논문은 대관령 실증단지에서 실시한 2MW 풍력시스템 실증과정에서 획득한 풍향과 풍속 데이터를 시각적으로 쉽게 보고 이해할 수 있도록 3D모델 처리방안을 적용하여 모의시험 장치에 구현한 내용이다. 풍력발전기 개발은 현재 대형화 추세에 있으며 연구개발 단계에서 풍력발전기의 발전 및 제어부분의 기능적 안정성 확보와 효율성 증대를 위한 적절한 시험은 필수적이다. 그러나 풍력발전기의 특성상 타워를 건설하고 회전자 블레이드를 사용하여 시험한다는 것은 설치 공간과 비용의 제약이 따른다. KBP-2000M (2MW) 모의시험장치는 풍력발전기와 같은 대형장비를 연구 개발하는데 필수적이며, 실증을 통해 획득한 Data를 적용함으로서 재품의 문제점을 찾아내고 성능향상을 도모하는데 필요하다. 실증 Data를 시각적으로 3D로 표현함으로서 현장의 풍속/풍향 변화를 사실감 있게 느끼게 되었다. 앞으로도 풍력발전기를 연구개발하거나 성능향상을 위해서는 적절한 제어와 안전을 위한 연동장치를 갖춘 스케일 다운된 모의시험장치 구축이 요구될 것이다. 풍력발전기의 실증과정에서 획득한 데이터를 모의시험장치에 적용(Feedback)하여 지속적인 성능향상을 높여나갈 것이다.

• Journal of IKEEE
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• v.16 no.3
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• pp.235-243
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• 2012

In this study, we developed two legged multi-joint robot by using wireless servo motor that was applied by wireless sensor network technology, which is widely used recently, and performed an experiment of walking method of two legged multi-joint robot. We constructed the star network with servo motors which were used at each joint of two-legged robot. And we designed the robot for operation by transmission of joint control signal from main control system or by transmission of the status of each joint to the main control system, so it operates with continuously checking the status of joints at same time. We developed the humanoid robot by using wireless digital servo motor which is different from existing servo motor control system, and controlled it by transmitting the information of angles and speeds of robot joints to the motor(node) as a feedback through main control system after connecting power and setting up the IDs to each joint. We solved noisy problem generated from wire and wire length to connection point of the control device by construction of the wireless network instead of using existing control method of wiring, and also solved problem of poor real time response to gait motion by controlling the position with continuous transmission of control signals to each joint. And we found that the effective control of robot is able by performing the simulation on walking motion in advance with the developed control algorithm which was downloaded into installed memory. Also we performed the stable walking with two-legged robot by attaching pressure sensor to robot sole. And we examined the robot gait operated by application of calculated algorithm on robot movement to each joint. In this study, we studied the method of controlling robot gait motion by using wireless servo motors and measured the torque applied to each joint, and found that the developed wireless servo motor by ZigBee sensor network offers easier control of two legged robot gait and better circuit configuration of it than the existing wired control system could do.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.237-243
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• 2015

In this paper, we consider a cascaded type of control architecture for a multi motor-based feedback control system and propose an ADC (Analog to Digital Converter) resource allocation method to efficiently utilize the limited ADC resources. The purpose of the resource allocation method is to minimize both the motor position measurement error and the d-q current measurement error. The cascaded type of control architecture is applied in parallel to each motor to independently control the speed of a motor in the multi motor control system. All the control algorithms are implemented by software using a single microcontroller without using additional microcontrollers. It is illustrated by experiments that the speed and the torque of each motor are controlled precisely by the proposed control architecture with the efficient ADC allocation method.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.211-216
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• 2015

Large hydraulic excavator weighted 90 tons used the several pumps installed in parallel to use the hydraulic pump driving gearbox to improve fuel consumption by improving the energy efficiency of the hydraulic system. Gearbox connected to hydraulic pump supply the mechanical output to the high pressure and low pressure pump to be supplied by torque and rotation, which are the mechanical power, through a input shaft connected to large size engine of the excavator. So, gearbox connected to hydraulic pump is same as main artery in the human body and is required long life because it operates the hydraulic pump continuously during operating the engine. This study had used oil contamination analysis method to check the wear characteristics of the gearbox and frequency response characteristic analysis method to check the failure of the teeth failures of gearbox, while the test equipment adopted by the electrical feedback method to reduce the energy consumption was operating for the life assessment, in which the required power was 600 kW input power.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1808-1817
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• 2017

Duties required for naval ship such as anti-submarine, anti-ship, and supply, etc are diversified, so the ECS (Enfineering Control System) is required for executing the mission effectively. The ECS monitors and controls the propulsion system in order that naval ship can perform the mission. As the in-country development of ECS is progressed, a test system for ECS is needed, and a naval ship propulsion system simulator based on CODOG was developed on this study. The naval ship propulsion system simulator based on CODOG which is divided into gas turbine model, diesel engine model, reduction gear model and controllable pitch propeller model, simulates to feedback of control commands of ECS. As a result of the experiment, it is able to confirm speed, torque and power, etc. of the gas turbine, diesel engine and shaft according to ECS propulsion mode.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3044-3050
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• 2015

The purpose of this study is to analyze the performance of the flow control oil pump for automatic transmission. The numerical model for analysis the performance of the flow control oil pump was develop and the characteristics of the internal flow, discharge flow rate, displacement of outer ring, driving torque, generation of cavitation was investigated according to rotating speed. As a result, the cavitation generation increased as the rotating speed increased. The volumetric efficiency was 90% for 2200 rpm and it decreased rapidly, then it decreased about 81% for 5000 rpm. Besides, the cavitation generation was 20%~30% for inlet of suction part, but it reduced below 13% owing to the compression. However, it shows higher cavitation generation for high rotating speed like 5000 rpm.