DocumentCode :
1048165
Title :
A Ripple-Mitigating and Energy-Efficient Fuel Cell Power-Conditioning System
Author :
Mazumder, Sudip K. ; Burra, Rajni K. ; Acharya, Kaustuva
Author_Institution :
Univ. of Illinois, Chicago
Volume :
22
Issue :
4
fYear :
2007
fDate :
7/1/2007 12:00:00 AM
Firstpage :
1437
Lastpage :
1452
Abstract :
We describe an energy-efficient, fuel-cell power-conditioning system (PCS) for stationary application, which reduces the variations in the current drawn from the fuel-cell stack and can potentially meet the $40/kW cost target. The PCS consists of a zero-ripple boost converter (ZRBC) followed by a soft-switched and multilevel high-frequency (HF) inverter and a single-phase cycloconverter. The ZRBC comprises a new zero-ripple filter (ZRF), which significantly reduces the input low- and high-frequency current ripples, thereby potentially enhancing the durability of the stack. A new phase-shifted sinewave modulation of the multilevel HF inverter is proposed, which results in the zero-voltage switching (ZVS) of all four switches without the use of any auxiliary circuit components. For such a sine wave modulation technique, >90% ZVS range is obtained per line cycle for about 70% of the rated load. Further, the line-frequency switching of the cycloconverter (at close to unity power factor) results in extremely low switching losses. The intermediate dc bus facilitates the inclusion of power systems based on other forms of alternative-energy techniques (e.g., photovoltaic/high-voltage stack). A 5 kW prototype of the proposed PCS is built, which currently achieves a peak efficiency of 92.4%. We present a detailed description of the operation of the PCS along with its key features and advantages. Finally, experimental results showing the satisfactory performance and the operation of the PCS are demonstrated.
Keywords :
cycloconvertors; fuel cell power plants; invertors; power filters; zero voltage switching; ZVS; alternative-energy techniques; fuel cell power-conditioning system; line-frequency switching; multilevel high-frequency inverter; phase-shifted sinewave modulation; power 5 kW; ripple mitigation; sine wave modulation technique; single-phase cycloconverter; zero-ripple boost converter; zero-ripple filter; zero-voltage switching; Costs; Energy efficiency; Filters; Fuel cells; Hafnium; Inverters; Personal communication networks; Phase modulation; Photovoltaic systems; Zero voltage switching; Active power filter (APF); conditioner; cycloconverter; efficiency; fuel cell; grid; inverter; modulation; multilevel; photovoltaics; power-conditioning system (PCS); ripple reduction; zero ripple filter (ZRF);
fLanguage :
English
Journal_Title :
Power Electronics, IEEE Transactions on
Publisher :
ieee
ISSN :
0885-8993
Type :
jour
DOI :
10.1109/TPEL.2007.900598
Filename :
4267769
Link To Document :
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