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 : Karshenas, Hamid Reza (검색결과 5 건)
- 무료
- 기관 내 무료
- 유료
-
A HARMONIC-FREE CURRENT-LINK AC TO AC POWER SUPPLY:DYNAMIC ANALYSIS AND DESIGN
Hamid R Karshenas,S B.Dewan 전력전자학회 1998 ICPE(ISPE)논문집 Vol.- No.-
In this paper, the dynamic analysis and design of an AC to AC power supply with DC current link is presented Despite many advantages of such a structure, its application in fixed frequency power supplies has received very little attention in the literature Different issues related to dynamic analysis of the proposed system are considered These include a simple averaging technique for modeling switching function generators, the concept of Internal Model Controllers, and necessary condition to avoid multiple crossing in ramp comparison methods Theoretical and experimental results obtained from a DSP-based laboratory type setup are presented.<br/>
-
Investigation of Instability in Multiple Grid-Connected Inverters with LCL Output Filters
Asghari, Fariba,Safavizadeh, Arash,Karshenas, Hamid Reza The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3
This paper deals with the instability and resonant phenomena in distribution systems with multiple grid-connected inverters with an LCL output filter. The penetration of roof-top and other types of small photovoltaic (PV) grid-connected systems is rapidly increasing in distribution grids due to the attractive incentives set forth by different governments. When the number of such grid-connected inverters increases, their interaction with the distribution grid may cause undesirable effects such as instability and resonance. In this paper, a grid system with several grid-connected inverters is studied. Since proportional-resonant (PR) controllers are becoming more popular, it is assumed that most inverters use this type of controller. An LCL filter is also considered at the inverters output to make the case as realistic as possible. A complete modeling of this system is presented. Consequently, it is shown that such a system is prone to instability due to the interactions of the inverter controllers. A modification of PR controllers is presented where the output capacitor is virtually decreased. As a result, the instability is avoided. Simulation results are presented and show a good agreement with the theoretical studies. Experimental results obtained on a laboratory setup show the validity of the analysis.
-
Electronic Ballast for HPS Lamps with Intrinsic Power Regulation over Lamp Life
Dehghani, Majid,Saghaiannejad, Seid Mortaza,Karshenas, Hamid Reza The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.4
This paper introduces the electronic ballast for high pressure sodium (HPS) lamps which provides power regulation during the whole lamp life without using a closed-loop power control system, in spite of large variations of lamp characteristics resulting from lamp aging. The structure of the electronic ballast and the parameters of HPS lamps are described. A mathematical model for the ballast is developed and used for the design and analysis of the ballast. A design procedure is presented to design the ballast which provides intrinsic power regulation over the whole lamp life. To improve the technical specifications of the ballast, the practical and standard constraints are considered in the design. According to the design procedure, an electronic ballast for 250-W HPS lamps is designed. All theoretical analyses are verified with the help of a semi-industrial experimental setup. The results validate that the designed ballast provides power regulation during the whole lamp life.
-
Electronic Ballast for HPS Lamps with Intrinsic Power Regulation over Lamp Life
Majid Dehghani,Seid Mortaza Saghaiannejad,Hamid Reza Karshenas 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.4
This paper introduces the electronic ballast for high pressure sodium (HPS) lamps which provides power regulation during the whole lamp life without using a closed-loop power control system, in spite of large variations of lamp characteristics resulting from lamp aging. The structure of the elcctronic ballast and the parameters of HPS lamps are described. A mathematical model for the ballast is developed and used for the design and analysis of the ballast. A design proccdure is presented to design the ballast which provides intrinsic power regulation over the whole lamp life. To improve the technical specifications of the ballast, the practical and standard constraints are considered in thc design. According to the design procedure, an electronic ballast for 250-W HPS lamps is designed. All theoretical analyses are verificd with thc help of a semi-industrial experimental setup. The results validate that the designed ballast providcs power regulation during the whole lamp life.
-
Investigation of Instability in Multiple Grid-Connected Inverters with LCL Output Filters
Fariba Asghari,Arash Safavizadeh,Hamid Reza Karshenas 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3
This paper deals with the instability and resonant phenomena in distribution systems with multiple grid-connected inverters with an LCL output filter. The penetration of roof-top and other types of small photovoltaic (PV) grid-connected systems is rapidly increasing in distribution grids due to the attractive incentives set forth by different governments. When the number of such grid-connected inverters increases, their interaction with the distribution grid may cause undesirable effects such as instability and resonance. In this paper, a grid system with several grid-connected inverters is studied. Since proportional-resonant (PR) controllers are becoming more popular, it is assumed that most inverters use this type of controller. An LCL filter is also considered at the inverters output to make the case as realistic as possible. A complete modeling of this system is presented. Consequently, it is shown that such a system is prone to instability due to the interactions of the inverter controllers. A modification of PR controllers is presented where the output capacitor is virtually decreased. As a result, the instability is avoided. Simulation results are presented and show a good agreement with the theoretical studies. Experimental results obtained on a laboratory setup show the validity of the analysis.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
