應用無ADC之FPGA控制於具零電壓零電流切換之升壓型轉換器

Applying FPGA Control Without ADC to ZVZCS Boost Converter

林志帆(Zhi-Fan Lin)

指導教授 ： 胡國英

國立臺北科技大學/電資學院/電機工程系所/碩士(2010年)

摘要

本論文係研製一具零電壓零電流切換(Zero Voltage and Zero Current Switching, ZVZCS)升壓型轉換器，加入一輔助功率開關、一共振電感及一共振電容等少量輔助元件，使得主功率開關兼具有零電壓切換(Zero Voltage Switching, ZVS)及零電流切換(Zero Current Switching, ZCS)，同時輔助功率開關亦具有零電流切換。除此之外，亦加入查表法(Look-Up Table)來實現自動調變技術(Auto-Tuning)以調控輔助功率開關的導通時間及觸發位置，以進一步提高效率，尤其是在輕載時，進而使得轉換器整體效率呈現一水平曲線。就系統控制而言，乃直接於 下來設計數位控制器。然而，數位控制須透過類比數位轉換器(Analog-to-Digital Converter, ADC)取樣回授訊號，因此提高成本。故本論文乃採用無 取樣技術於輸入電流取樣及輸出電壓取樣，並以場效邏輯閘陣列(Field Programmable Gate Array, FPGA)作為系統控制核心以實現系統之全數位化控制。最後，藉由理論推導、模擬及實驗來驗證所提架構之可行性及有效性。

關鍵字

自動調變技術升壓型轉換器 ； FPGA ； 全數位化 ； 柔性切換 ； 無ADC取樣技術 ； z-domain控制器設計 ； 零電壓零電流切換

並列摘要

In this thesis, a boost converter with zero voltage and zero current switching (ZVZCS) is developed, which is implemented only by one auxiliary switch, one resonant inductor and one resonant capacitor as compared to the traditional boost converter. In this topology, the main switch has zero voltage and zero current switching whereas the auxiliary switch has zero current switching. Aside from this, the auto-tuning technique based on a given look-up table is added to adjust the turn-on instant and time of the auxiliary switch, so that the efficiency is further upgraded, particularly at light load. Hence the curve of efficiency versus load current is made nearly flat all over the load range. Regarding the system control, the z-domain controller design is used, that is to say, the digital controller is designed directly from the z-domain. However, the analog-to-digital converter (ADC) used to transfer the analog signal to the digital signal is indispensable for the traditional digital control, and hence the accompanying cost is increased. Consequently, the one-comparator sampling technique without any ADC is utilized herein to obtain information on the input current and output voltage of the converter. Moreover, the field programmable gate array (FPGA) is used as a system control kernel to realize fully-digitalized control. Eventually, a detailed description of the behavior of the proposed topology and its mathematical deduction are presented along with some simulated and experimental results, which are employed to demonstrate its feasibility and effectiveness.

並列關鍵字

Auto-Tuning ； Boost Converter ； FPGA ； Fully-Digitalized ； Soft Switching ； Sampling Without ADC ； Z-Domain Controller Design ； Zero Voltage and Zero Current Switching

參考文獻

[60] 賈證主，VHDL數位系統設計與應用，台北：台科大圖書股份有限公司，2004。

[1] L. Brush, “Trends in digital power management: power converter and system

characteristics,” IEEE Transactions on Power Electronics, vol. PE-2, no. 1, pp. 62-71, 1987.

[3] F. C. Lee, “High-frequency quasi-resonant converter technologies,” Proceedings of the IEEE, vol. 76, no. 4, pp. 377-390, 1988.

[4] F. C. Lee, “High-frequency quasi-resonant and multi-resonant converter technologies,” IEEE IECON’88, vol. 3, pp. 509-521, 1988.