• Title, Summary, Keyword: Submodule stack

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Submodule Level Distributed Maximum Power Point Tracking PV Optimizer with an Integrated Architecture

  • Wang, Feng;Zhu, Tianhua;Zhuo, Fang;Yi, Hao;Shi, Shuhuai
    • Journal of Power Electronics
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    • v.17 no.5
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    • pp.1308-1316
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    • 2017
  • The distributed maximum power point tracking (DMPPT) concept is widely adopted in photovoltaic systems to avoid mismatch loss. However, the high cost and complexity of DMPPT hinder its further promotion in practice. Based on the concept of DMPPT, this paper presents an integrated submodule level half-bridge stack structure along with an optimal current point tracking (OCPT) control algorithm. In this full power processing integrated solution, the number of power switches and passive components is greatly reduced. On the other hand, only one current sensor and its related AD unit are needed to perform the ideal maximum power generation for all of the PV submodules in any irradiance case. The proposal can totally eliminate different small-scaled mismatch effects in real-word condition and the true maximum power point of each PV submodule can be achieved. As a result, the ideal maximum power output of the whole PV system can be achieved. Compared with current solutions, the proposal further develops the integration level of submodule DMPPT solutions with a lower cost and a smaller size. Moreover, the individual MPPT tracking for all of the submodules are guaranteed.

Operation Results of a 5kW-Class SOFC System Composed of 2 Sub-Module Stacks (2 모듈 스택을 이용한 5kW급 SOFC 시스템 운전결과)

  • Lee, Tae-Hee;Choi, Mi-Hwa;Yoo, Young-Sung
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.5
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    • pp.609-615
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    • 2011
  • A 5 kW class SOFC system for cogeneration power units was consisted of a hot box part and cold BOPs. High temperature components such as a stack, a fuel reformer, a catalytic combustor, and heat exchanges are arranged in the bot box considering their operating temperatures for the system efficiency. The hot box was made of ceramic boards for the thermal insulation. A 5 kW class SOFC stack was composed of 2 sub-modules and each module had 64 cells with $15{\times}15cm^2$ area and stainless steel interconnects. The 5 kW class SOFC system was operated with a hydrogen and a city gas. With a hydrogen, the total power of the stacks was about 7.1 kWDC and electrical efficiency was about 49.3% at 80 A. With a city gas, the total power of the stacks was about 5.7 $kW_{DC}$ and electrical efficiency was about 38.8% at 60 A. Under self-sustained operating condition, the system efficiency including a power conditioning loss and a consumed power by BOPs was about 30.2%.