由於天氣因素會對太陽能電池的輸出功率造成劇烈變化，為了確保電網的供電品質，因此太陽能電池與電網之間穩定的電能轉換顯得非常重要，本論文發展一太陽能發電系統之電能轉換介面，其由三埠直流電能轉換器、七階雙降壓直流-交流換流器和超級電容模組組成，能夠將太陽能電池所產生的直流功率轉換成交流功率注入電網，並通過超級電容模組的儲能與釋能以減緩天氣等環境因素對太陽能發電系統輸出功率所產生的劇烈變化，本文所提電能轉換介面採用雙降壓換流器架構，其可改善無變壓器太陽能發電系統中太陽能電池與地之間的洩漏電流問題，且七階雙降壓直流-交流換流器只利用六個電力電子開關來產生七階輸出電壓，可有效降低輸出濾波器容量及電磁干擾，並簡化電力電路，此外可避免電流流經電力電子開關之旁路二極體，因此電力電子開關可選用MOSFET來提升效率。為了驗證本論文所提電能轉換介面之功能及控制方法的可行性，本論文發展一電路雛形以驗證其功能。

關鍵字:雙降壓直流-交流換流器、多階電能轉換器、洩漏電流。

Environmental factors will cause drastic changes in the output power of solar cell array. In order to ensure the power quality of the utility system, stable power conversion between solar cell array and the utility system is very important. This thesis develops a power conversion interface for a solar power generation system, which consists of a three-port DC power converter, a seven-level dual-buck DC-AC inverter and a supercapacitor module. The power conversion interface can convert the DC power generated by the solar cell into AC power and inject it into the utility system. Besides, the power conversion interface can slow down the drastic changes in the output power of the solar cell array caused by environmental factors through the energy storage and release of the supercapacitor module. The structure of dual-buck inverter is used in the power conversion interface to solve the problem of leakage current due to the parasitic capacitance of the solar cell array in the transformerless solar power generation system. The seventh-level dual-buck DC-AC inverter can generate a seventh-level AC voltage, which can effectively reduce the capacity of output filter and electromagnetic interference, and simplify the power circuit. The seven-level dual-buck DC-AC inverter only uses six power electronic switches to simplify the power circuit. Moreover, the seven-level double-buck DC-AC inverter can avoid current flowing through the parallel diodes of the power electronic switches, so MOSFETs can be used to improve the power efficiency. In order to verify the feasibility of the proposed power conversion interface, a prototype is developed.

Keywords: dual-buck DC-AC inverter, multi-level converter, leakage current.

摘 要 i
ABSTRACT ii
誌謝 iii
圖目錄 vi
表目錄 x
第一章 緒論 1
1-1 前言 1
1-2 研究動機與目的 4
1-3 論文大綱 5
第二章 太陽能發電系統之洩漏電流 6
2-1 洩漏電流 6
2-2 全橋式直流-交流換流器 7
2-2-1 單極性脈波寬度調變 9
2-2-2 雙極性脈波寬度調變 12
2-3 降低洩漏電流之直流-交流換流器 14
2-3-1 H5直流-交流換流器 14
2-3-2 HERIC直流-交流換流器 17
2-4 雙降壓直流-交流換流器 20
2-4-1 三階雙降壓直流-交流換流器 20
2-4-2 單電感三階雙降壓直流-交流換流器 28
2-4-3 五階雙降壓直流-交流換流器 32
第三章 使用七階雙降壓直流-交流換流器之電能轉換介面 36
3-1 電能轉換介面之操作 36
3-2 七階雙降壓直流-交流換流器 39
3-2-1 電路架構 39
3-2-2 操作原理 40
3-2-3 洩漏電流 48
3-2-4 控制方塊 49
3-2-5 直流-交流換流器之比較 51
3-3 三埠直流電能轉換器 52
3-3-1 電路架構 52
3-3-2 操作原理 53
3-3-3 控制方塊 56
3-4 程式控制流程圖[25] 57
3-5 儲能模組[26] 58
第四章 模擬結果 60
4-1 模擬分析 60
4-2 功率半導體元件損失分析 63
4-2-1 IGBT之損失 64
4-2-2 MOSFET之損失 64
4-2-3 二極體之損失[28]-[30] 65
4-3 損失分析模擬 66
第五章 實驗結果與討論 74
5-1 電路元件規格 74
5-2 穩態響應 77
5-3 暫態響應 81
5-4 洩漏電流 83
5-5 最大功率追蹤 84
5-6 效率實測結果 85
5-7 輸出功率平滑化之實測結果 86
第六章 結論與未來展望 90
6-1 結論 90
6-2 未來展望 91
參考文獻 92

[1]中華民國外交部:聯合國氣候變化綱要公約(UNFCCC),[Online],
https://subsite.mofa.gov.tw/igo/cl.aspx?n=7ab43476636ec0ed
[2]綠色貿易資訊網:淨零碳排專區-政策法規,[Online],
https://www.greentrade.org.tw/purchasing_info?page=1&industryID=430
[3]中小企業綠色環保資訊網:再生能源發展條例,[Online],
https://green.pidc.org.tw/detail.php?lang=tw&type=1&id=2164
leakage current
[4]M. N. H. Khan, M. Forouzesh, Y. P. Siwakoti, L. Li, T. Kerekes and F. Blaabjerg, (2019) "Transformerless Inverter Topologies for Single-Phase Photovoltaic Systems: A Comparative Review," IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 8, no. 1, pp. 805-835.
[5]T. K. S. Freddy, J. H. Lee, H. C. Moon, K. B. Lee and N. A. Rahim, (2017) "Modulation Technique for Single-Phase Transformerless Photovoltaic Inverters With Reactive Power Capability," IEEE Transactions on Industrial Electronics, vol. 64, no. 9, pp. 6989-6999.
[6]R. Gonzalez, J. Lopez, P. Sanchis and L. Marroyo, (2007) "Transformerless Inverter for Single-Phase Photovoltaic Systems," IEEE Transactions on Power Electronics, vol. 22, no. 2, pp. 693-697.
[7]洪誌翊 (2016)。「無隔離變壓器之多階太陽能發電系統」。碩士論文，國立高雄海洋科技大學微電子工程研究所。
[8]H. Li, Y. Zeng, B. Zhang, T. Q. Zheng, R. Hao and Z. Yang, (2019) "An Improved H5 Topology With Low Common-Mode Current for Transformerless PV Grid-Connected Inverter," IEEE Transactions on Power Electronics, vol. 34, no. 2, pp. 1254-1265.
[9]M. R. Islam, M. M. Hasan, F. R. Badal, S. K. Das and S. K. Ghosh, (2020) "A Blended Improved H5 Topology With ILQG Controller to Augment the Performance of Microgrid System for Grid-Connected Operations," IEEE Access, vol. 8, pp. 69639-69660.
[10]K. S. Kumar, A. Kirubakaran and N. Subrahmanyam, (2020) "Bidirectional Clamping-Based H5, HERIC, and H6 Transformerless Inverter Topologies With Reactive Power Capability," IEEE Transactions on Industry Applications, vol. 56, no. 5, pp. 5119-5128.
[11]M. Shahabadini, N. Moeini, M. Bahrami-Fard and H. Iman-Eini, (2023) "HERIC-Based Cascaded H-Bridge Inverter for Leakage Current Suppression in PV Systems," IEEE Transactions on Power Electronics, vol. 38, no. 3, pp. 4005-4014.
[12]P. Sun, C. L. Chen, J. S. Lai and C. Liu, (2012) "Cascade dual-buck full-bridge inverter with hybrid PWM technique," 2012 Twenty-Seventh Annual IEEE Applied Power Electronics Conference and Exposition (APEC), Orlando, FL, USA, 2012, pp. 113-119.
[13]Z. Yao, L. Xiao and Y. Yan, (2009) "Dual-Buck Full-Bridge Inverter With Hysteresis Current Control," IEEE Transactions on Industrial Electronics, vol. 56, no. 8, pp. 3153-3160.
[14]L. Wang, Y. Li, Q. Yan and W. Dou, (2016) "Dual buck grid-connected inverter based on GaN devices," 2016 Asian Conference on Energy, Power and Transportation Electrification (ACEPT), Singapore, 2016, pp. 1-6.
[15]B. Chen, B. Gu, J. S. Lai, W. Yu, C. Y. Lin and C. Zheng, (2013) "Current distortion correction in dual buck photovoltaic inverter with a novel PWM modulation and control method," 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), Long Beach, CA, USA, 2013, pp. 727-731.
[16]L. Zhou and F. Gao, (2016) "Improved transformerless dual buck inverters with buffer inductors," 2016 IEEE Applied Power Electronics Conference and Exposition (APEC), Long Beach, CA, USA, 2016, pp. 2935-2941.
[17]F. Hong, J. Liu, B. Ji, Y. Zhou, J. Wang and C. Wang, (2016) "Interleaved Dual Buck Full-Bridge Three-Level Inverter," IEEE Transactions on Power Electronics, vol. 31, no. 2, pp. 964-974.
[18]L. Zhou and F. Gao, (2016) "Dual buck inverter with series connected diodes and single inductor," 2016 IEEE Applied Power Electronics Conference and Exposition (APEC), Long Beach, CA, USA, 2016, pp. 2259-2263.
[19]F. Hong, J. Liu, B. Ji, Y. Zhou, J. Wang and C. Wang, (2015) "Single Inductor Dual Buck Full-Bridge Inverter," IEEE Transactions on Industrial Electronics, vol. 62, no. 8, pp. 4869-4877.
[20]T. R. Amalraj, B. M. Jos and A. M. Kottalil, (2017) "Feed forward controlled dual buck full-bridge inverter," 2017 International Conference on Technological Advancements in Power and Energy (TAP Energy), Kollam, India, 2017, pp. 1-6.
[21]T. T. Nguyen, H. Cha, B. L. H. Nguyen and H. G. Kim, (2018) "Novel T-type Dual-Buck Inverter with Minimum Number of Inductors," 2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia), Niigata, Japan, 2018, pp. 1046-1050.
[22]L. Zhang, K. Sun, Y. Xing and J. Zhao, (2016) "A Family of Five-Level Dual-Buck Full-Bridge Inverters for Grid-Tied Applications," IEEE Transactions on Power Electronics, vol. 31, no. 10, pp. 7029-7042.
[23]N. Sun, L. Zhang, Y. Xing, M. Xu, Y. Fang, and X. Ma, (2011) "A five level dual buck full bridge inverter with neutral point clamp for grid connected PV application," IECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society, Melbourne, VIC, Australia, 2011, pp. 1041-1045.
[24]Z. Yao, (2021) "Review of Dual-Buck-Type Single-Phase Grid-Connected Inverters," IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 9, no. 4, pp. 4533-4545.
[25]張仲勛 (2021)。「具輸出功率平滑化之小容量太陽能發電系統」。碩士論文，國立高雄科技大學半導體工程系。
[26]施尚逸 (2020)。「適用於太陽能平滑化控制之新型直流耦合混合式儲能系統之研究」。碩士論文，國立高雄科技大學電機工程系。
[27]江炫樟 (2008) "電力電子學" 全華科技圖書股份有限公司, 第三版。
[28]张洪亮 (2017) "功率二极管在电源里的损耗分析和选型原则"。
[29]M. Frivaldsky and R. Sul, (2008) "Elimination of transistor’s switching losses by diode reverse recovery in dedicated application," 2008 34th Annual Conference of IEEE Industrial Electronics, Orlando, FL, USA, 2008, pp. 737-742.
[30]Microelectronics, S. T. (2017) AN5028: Calculation of turn-off power losses generated by an ultrafast diode.
[31]PSIM Thermal: Power Loss Calculation,[Online],https://powersimtech.com/products/psim/psim-modules/thermal/