http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Huiwen Deng (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
-
Low Frequency Current Ripple Mitigation of Two Stage Three-Phase PEMFC Generation Systems
Huiwen Deng,Qi Li,Zhixiang Liu,Lun Li,Weirong Chen 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6
This paper presents a two stage three-phase proton exchange membrane fuel cell (PEMFC) generation system. When the system is connected to a three-phase load, it is very sensitive to the characteristics and type of the load. Especially unbalanced three-phase loads, which result in a pulsating power that is twice the output frequency at the inverter output, and cause the dc-link to generate low frequency ripples. This penetrates to the fuel cell side through the front-end dc-dc converter, which makes the fuel cell work in an unsafe condition and degrades its lifespan. In this paper, the generation and propagation mechanism of low frequency ripple is analyzed and its impact on fuel cells is presented based on the PEMFC output characteristics model. Then a novel method to evaluate low frequency current ripple control capability is investigated. Moreover, a control scheme with bandpass filter inserted into the current feed-forward path, and ripple duty ratio compensation based on current mode control with notch filter is also proposed to achieve low frequency ripple suppression and dynamic characteristics improvement during load transients. Finally, different control methods are verified and compared by simulation and experimental results.
-
Low Frequency Current Ripple Mitigation of Two Stage Three-Phase PEMFC Generation Systems
Deng, Huiwen,Li, Qi,Liu, Zhixiang,Li, Lun,Chen, Weirong The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6
This paper presents a two stage three-phase proton exchange membrane fuel cell (PEMFC) generation system. When the system is connected to a three-phase load, it is very sensitive to the characteristics and type of the load. Especially unbalanced three-phase loads, which result in a pulsating power that is twice the output frequency at the inverter output, and cause the dc-link to generate low frequency ripples. This penetrates to the fuel cell side through the front-end dc-dc converter, which makes the fuel cell work in an unsafe condition and degrades its lifespan. In this paper, the generation and propagation mechanism of low frequency ripple is analyzed and its impact on fuel cells is presented based on the PEMFC output characteristics model. Then a novel method to evaluate low frequency current ripple control capability is investigated. Moreover, a control scheme with bandpass filter inserted into the current feed-forward path, and ripple duty ratio compensation based on current mode control with notch filter is also proposed to achieve low frequency ripple suppression and dynamic characteristics improvement during load transients. Finally, different control methods are verified and compared by simulation and experimental results.
-
Nonlinear Increase of Spatial Noise for Ultrashort Pulses with Different Temporal Widths
Lifu Zhang,Xiquan Fu,Jianqin Deng,Hua Yang,Youwen Wang,Shuangchun Wen,Huiwen Xu,Jinggui Zhang,Jin Zhang,Dianyuan Fan 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.2
In this paper, the dynamic evolution of the spatial noise modulation of ultrashort laser pulses in carbon disulfide (CS2) is investigated experimentally, and different temporal widths of the stretched pulse are analyzed for spatial noise gain. The spatial noise evolution (i.e., small-scale self-focusing) of ultrashort laser pulses with different temporal widths as a function of the length of the CS2 has been observed. If the spectral bandwidth is invariant, the experimental results show that a stretched pulse with a broader temporal width can postpone the small-scale self-focusing of spatial noise for longer medium length with constant input power or for greater input power with the same medium length. In this paper, the dynamic evolution of the spatial noise modulation of ultrashort laser pulses in carbon disulfide (CS2) is investigated experimentally, and different temporal widths of the stretched pulse are analyzed for spatial noise gain. The spatial noise evolution (i.e., small-scale self-focusing) of ultrashort laser pulses with different temporal widths as a function of the length of the CS2 has been observed. If the spectral bandwidth is invariant, the experimental results show that a stretched pulse with a broader temporal width can postpone the small-scale self-focusing of spatial noise for longer medium length with constant input power or for greater input power with the same medium length.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
