輸入電壓波形失真

本小節將考慮輸入電壓波形失真的情況，對無電流感測控制架構進行實作。輸入電 壓波形失真，將會對無電流感測控制架構造成不良的影響。圖4.20 為各負載功率時的輸 入電壓及輸入電流實作波形。觀察可以發現，在輸入電壓失真時，輸入電流的波形亦變 的非常差。主要的原因為，在無電流感測控制架構中，假設輸入電壓為純弦波，且僅偵 測輸入電壓波形之相位，利用查表的方式得到開關訊號的依據。因此當輸入電壓波形失 真時，開關訊號所依據的輸入電壓波形無法同時改變，故造成了輸入電流波形不良的影 響。伴隨著輸入電流波形改變而來的，即為功率因數低落及總諧波失真增加的結果，數 據整理於表4.7 中。

10ms

vs

is

0 -5A 50V

(a)

10ms

vs

is

0 -5A 50V

(b)

10ms

vs

is

0 -10A

50V

(c)

圖4.20. 輸入電壓波形失真之輸入電壓及輸入電流波形：(a)675W；(b)450W；(c) 225W。

表4.7 輸入電壓波形失真時之量測數據 675W 450W 225W

vin

%THD 6.09% 6.03% 5.55%

iin

%THD 45.88% 58.64% 76.59%

PF 0.89 0.80 0.68

第五章 結論

本論文主要提出了一新的無電流感測控制架構，用於單相切換式整流器，並取代傳 統的多迴路控制架構。與傳統的多迴路控制架構做比較，無電流感測控制架構僅需迴授 輸入電壓及輸出電壓，並利用一 PI 控制器即可以達到輸出穩壓之效果。接著利用 PI 控 制器輸出的相角訊號即可以調整輸入電流之波形，達到功因校正的效果。

本論文除了對於單相切換式整流器之原理以及無電流感測控制架構之功能進行了 詳盡的介紹外，更利用電腦模擬軟體 PSIM 來驗證無電流感測架構理論之可行性。最後 利用 FPGA 實現無電流感測架構，在輸入 110V 的電壓的狀況下得到穩定的輸出電壓 300V 以及輸入電流波形修飾的效果。根據實作結果，若希望符合 IEC 61000-3-2 A 類規 範則可以考慮使用簡化四架構但需將操作功率低於 675W；IEC 61000-3-2 D 類規範則可 以考慮使用簡化一架構。

然而因為在數位系統有限的解析度下，無電流感測控制架構操作在較低負載功率 時，電流波形的總諧波失真將較大。此外，當輸入電壓波形失真時，由無電流感測控制 架構得到之輸入電流波形，其諧波影響將會增加。原因在於因為無電流感測控制架構是 基於輸入電壓波形為純弦波的假設下，故當輸入電壓波形失真時，則需將無電流感測控 制架構進行修正。

參考文獻

[1] S. B. Dewan, “Optimum Input and Output Filter for a Single-Phase Rectifier Power Supply,” IEEE Trans. on Industry Application, vol. 17, no. 3, pp. 282-288, May, 1981.

[2] O. Garcia, J. A. Cobos, R. Prieto, P. Alou, and J. Uceda, “Single phase Power Factor Correction: A Survey,” IEEE Trans. on Power Electronics, vol. 18, no. 3, pp. 749-754, May, 2003.

[3] J. B. Williams, “Design of Feedback Loop in Unity Power Factor AC to DC Converter,”

in Proc. PESC’89, 1989, pp. 959-967.

[4] H. C. Chen, S. H. Li, and C. M. Liaw, “Switch-Mode Rectifier with Digital Robust Ripple Compensation and Current Waveform Controls”, IEEE Trans. on Power Electronics, vol. 19, no. 2, pp. 560-566, Mar. 2004.

[5] M. Chen, and J. Sun, “Feedforward Current Control of Boost Single-Phase PFC Converters,” IEEE Trans. on Power Electronics, vol. 21, no. 2, pp. 338-345, Mar. 2006.

[6] D. M. Van de Sype, K. De Gusseme, A. P. Van den Bossche, and J. A. Melkbeek,

“Duty-Ratio Feedforward for Digitally Controlled Boost PFC Converters,” IEEE Trans.

on Industrial Electronics, vol. 52, no. 1, pp. 108-115, Feb. 2005.

[7] E. Fiqueres, J. M. Benavent, G. Garcera and M. Pascual, “Robust Control of Power-Factor-Correction Rectifiers with Fast Dynamic Response,” IEEE Trans. on Industrial Electronics, vol. 52, no. 1, pp. 66-76, Feb. 2005.

[8] J. Chen, A. Prodic, R. W. Erickson, and D. Maksimovic, “Predictive Digital Current Programmed Control,” IEEE Trans. on Power Electronics, vol. 18, no. 1, pp. 411-419, Jan. 2003.

[9] W. Zhang, G. Feng, Y. F. Liu, and B. Wu, “A Digital Power Factor Correction (PFC) Control Strategy Optimized for DSP,” J. Chen, A. Prodic, R. W. Erickson, and D.

Maksimovic, “Predictive Digital Current Programmed Control,” IEEE Trans. on Power Electronics, vol. 19, no. 6, pp. 1474-1485, Nov. 2004.

[10] S. C. Yip, D. Y. Qiu, H. S. Chung, and S. Y. R. Hui, “A Novel Voltage Sensorless Control

Technique for a Bidirectional AC/DC Converter”, IEEE Trans. on Power Electronics, vol. 18, no. 6, pp. 1346-1355, Nov. 2003.

[11] A. Pandeym B. Singh, and D. P. Kothari, “A Novel DC Bus Voltage Sensorless PFC Rectifier with Improved Voltage Dynamics”, in IEEE IECON’02, pp. 226-228, 2002.

[12] S. Sivakumar, K. Natarajan, and R. Gudelewics, “Control of Power Factor Correcting Boost Converter Without Instantaneous Measurement of Input Current”, IEEE Trans. on Power Electronics, vol. 10 no. 4, pp. 435-445, Jul. 1995.

[13] J. Sebastian, J. A. Martinez, J. M. Alonso and J. A. Cobos, “Voltage-Follower Control in Zero-Current-Switched Quasi-Resonant Power Factor Preregulators”, IEEE Trans. on Power Electronics, vol. 13, no. 4, pp. 727-738, Jul. 1998.

[14] D. Maksimovic, Y. Jang, and R. W. Erickson, “Nonlinear-Carrier Control for High-Power-Factor Boost Rectifiers”, IEEE Trans. on Power Electronics, vol. 11, no. 4, pp. 578-584, Jul. 1996.

[15] J. Rajagopalan, F. C. Lee, and P. Nora, “A General Technique for Derivation of Average Current Mode Control Laws for Single-Phase Power-Factor-Correction Circuit Without Input Voltage Sensing”, IEEE Trans. on Power Electronics, vol. 14, no. 4, pp. 663-672, Jul. 1999.

[16] H. C. Chen, “Duty Phase Control for Single-Phase Boost-Type SMR”, IEEE Trans. on Power Electronics, vol. 23, no. 4, pp. 1927-1934, Jul. 2008.

[17] E. Monmasson, M. N. Cirstea, “FPGA Design Methodology for Industrial Control Systems-A Review”, IEEE Trans. on Industrial Electronics, vol. 54, no. 4, pp.

1824-1842, Aug. 2007.

[18] Xilnx, Spartan-3 FPGA Family Data Sheet, 2008.