RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • KCI등재

        Design Methodology of LLC Resonant Converters for Single-stage Power Factor Correction Application

        Zhou Yufei,Liu Shuai,Ren Jiaqi,Wu Qibin,Hong Feng,Shen Ang,Xu Wei 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5

        This paper proposes a new design methodology for LLC resonant converter with single-stage power factor correction (PFC) function. By designing the achievable gain of resonant tank at a certain point of the AC voltage higher than the required gain, its gain will satisfy the requirement of the whole AC line voltage cycle and lead to a good single-stage PFC design. By adjusting switching frequency and changing voltage gain along with the AC voltage, the converter can realize PFC with high effi ciency. The proposed converter inherits the advantages of the traditional LLC resonant converter, including soft switching of power switches across the whole load range, buck-boost power conversion ability which benefi ts the optimization of the down-stream DC-DC converter. Gain characteristic and design consideration for PFC purpose are analyzed in detail. Experimental results are presented to show its validity and feasibility.

      • KCI등재

        Evaluation of the Efficacy of a Lactobacilli-Based Teat Detergents for the Microbiota of Cows Teats Using an Untargeted Metabolomics Approach

        Yan Rui,Ji Zhongqing,Fan Jiaqi,Li Jiang,Ren Yan 한국미생물·생명공학회 2024 Journal of microbiology and biotechnology Vol.34 No.1

        Teat cleaning pre- and post-milking is important for the overall health and hygiene of dairy cows. The purpose of this research was to evaluate the effectiveness of a teat detergents based on lactic acid bacteria according to changes in somatic cell count and cow-milk metabolites. Sixty-nine raw milk samples were collected from 11 Holstein-Friesian cows in China during 12 days of teat cleaning. An ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry-based untargeted metabolomic approach was applied to detect metabolomic differences after treatment with lactic acid bacteria and chemical teat detergents in cows with subclinical mastitis. The results suggest that the lactobacilli-based teat detergents could reduce somatic cell count and improve microhabitat of cow teat apex by adjusting the composition of metabolites. Furthermore, the somatic cell count could be decreased significantly within 10 days following the cleaning protocol. Lactic acid bacteria have the potential to be applied as a substitution to teat chemical detergents before and after milking for maintenance of healthy teats and breasts. Further, larger scale validation work is required to support the findings of the current study.

      • KCI등재

        Efficiency optimization of variable‑frequency controlled power factor correction converters

        Yufei Zhou,Xueru He,Shuai Liu,Feng Hong,Jiaqi Ren,Dongdong Li 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.6

        More attention is being paid to energy effi ciency and harmonic reduction. Thus, power factor correction (PFC) is widely used in power supplies. However, under the condition of light load, the single-stage LLC PFC converter has the problems of low effi ciency and output voltage misaligned, such as other PFC topologies. Aiming at the problems that occur under light load conditions, this paper proposes a least-pulse delta (Δ)–sigma (Σ) modulation (LPΔ–Σ modulation). Under diff erent loads, the system can automatically select the appropriate pulse density and reduce the energy transfer to the secondary side by uniformly turning off the driving signals, which stabilizes the output voltage and improves the system effi ciency. Meanwhile, LPΔ–Σ modulation is more benefi cial for improving the PF value when compared with the burst mode under light load conditions. Experimental results show that LPΔ–Σ modulation based on the traditional dual-loop control can eff ectively stabilize the output voltage and improve effi ciency. When compared with the existing burst control scheme, it reduces the output voltage ripple and eff ectively improves the PF.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼