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Sungsu Cha,Yujong Kim,Jinsik Ju,Youngwoo Joo,Byeong-No Lee,Soo Min Lee,Jae Hyun Kim,Pikad Buaphad,Byung Cheol Lee,Hyungki Cha,Jang Ho Ha,Hyung Dal Park,Ki Beak Song,Seung Hyun Lee,Heesoo Kim 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.6
The Korea Atomic Energy Research Institute (KAERI) has been developing a Container Inspection System (CIS) by using a dual-energy (9/6 MeV) S-band (= 2856 MHz) electron linear accelerator. The key components of the CIS are the electron linear accelerator (including an electron gun, an accelerating structure, an RF power source, cooling chillers, vacuum pumps, magnet power supplies, and two solenoid magnets with beam focusing and shielding functions), a tungsten target for X-ray generation, an X-ray collimator, a detector array, and a container moving system. Generally, in accelerators, beam focusing is mainly done by solenoids operating in the region of a few MeV to keep the shape of transverse beam symmetrically round so as to reduce the loss of electrons, which increases the beam current and the beam power. In addition, a specially-designed component is needed to protect against the radiation due to the lost electrons. In this paper, we describe the design, fabrication, and optimization of two specially- designed solenoids with focusing and radiation shielding functions for a dual-energy S-band electron linear accelerator for a CIS.
수산화물과 지지체를 이용한 객실용 이산화탄소 흡착제 연구
조영민(Youngmin Cho),최진식(Jinsik Choi),양영민(Youngmin Yang),권순박(Soon-Bark Kwon),박덕신(Duck-shin Park),이주열(Ju-Yeol Lee) 한국철도학회 2012 한국철도학회 학술발표대회논문집 Vol.2012 No.5
지하철 객실의 이산화탄소 농도는 '대중교통수단의 실내공기질 가이드라인'에 의해 첨두시간과 비첨두시간에 각각 일정 수준 이하로 유지하여야 한다. 그러나, 첨두시간에는 탑승 승객수가 많기 때문에 가이드라인 값을 초과하는 경우가 많다. 그럼에도 불구하고 지하철은 외기가 터널의 미세먼지로 오염되어 있는 경우가 많아 환기도 쉽지 않다. 이에 본 연구에서는 수산화물을 활성탄, 제올라이트, 실리카 등의 다양한 지지체와 혼합한 이산화탄소 흡착제를 만들고, 만든 흡착제의 이산화탄소 흡착성능을 알아보았다. 지지체의 종류, 이산화탄소 혼합기체의 유량, 흡착제의 양, 운반기체의 종류에 따른 흡착성능의 변화를 확인함으로써 최적의 흡착제 제조 조건을 도출하고자 하였다.
Adaptive Gain-based Stable Power Smoothing of a DFIG
Hyewon Lee,Min Hwang,Jinsik Lee,Eduard Muljadi,Hong-Ju Jung,Yong Cheol Kang 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.6
In a power system that has a high wind penetration, the output power fluctuation of a large-scale wind turbine generator (WTG) caused by the varying wind speed increases the maximum frequency deviation, which is an important metric to assess the quality of electricity, because of the reduced system inertia. This paper proposes a stable power-smoothing scheme of a doubly-fed induction generator (DFIG) that can suppress the maximum frequency deviation, particularly for a power system with a high wind penetration. To do this, the proposed scheme employs an additional control loop relying on the system frequency deviation that operates in combination with the maximum power point tracking control loop. To improve the power-smoothing capability while guaranteeing the stable operation of a DFIG, the gain of the additional loop is modified with the rotor speed and frequency deviation. The gain is set to be high if the rotor speed and/or frequency deviation is large. The simulation results based on the IEEE 14-bus system demonstrate that the proposed scheme significantly lessens the output power fluctuation of a WTG under various scenarios by modifying the gain with the rotor speed and frequency deviation, and thereby it can regulate the frequency deviation within a narrow range.
Adaptive Gain-based Stable Power Smoothing of a DFIG
Lee, Hyewon,Hwang, Min,Lee, Jinsik,Muljadi, Eduard,Jung, Hong-Ju,Kang, Yong Cheol The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.6
In a power system that has a high wind penetration, the output power fluctuation of a large-scale wind turbine generator (WTG) caused by the varying wind speed increases the maximum frequency deviation, which is an important metric to assess the quality of electricity, because of the reduced system inertia. This paper proposes a stable power-smoothing scheme of a doubly-fed induction generator (DFIG) that can suppress the maximum frequency deviation, particularly for a power system with a high wind penetration. To do this, the proposed scheme employs an additional control loop relying on the system frequency deviation that operates in combination with the maximum power point tracking control loop. To improve the power-smoothing capability while guaranteeing the stable operation of a DFIG, the gain of the additional loop is modified with the rotor speed and frequency deviation. The gain is set to be high if the rotor speed and/or frequency deviation is large. The simulation results based on the IEEE 14-bus system demonstrate that the proposed scheme significantly lessens the output power fluctuation of a WTG under various scenarios by modifying the gain with the rotor speed and frequency deviation, and thereby it can regulate the frequency deviation within a narrow range.