Digital Control Algorithm Based on Delta-Operator for High-Frequency DC-DC Switching Converters

Authors: Renkai Wang, Tingcun Wei

Abstract:

In this paper, a digital control algorithm based on delta-operator is presented for high-frequency digitally-controlled DC-DC switching converters. The stability and the controlling accuracy of the DC-DC switching converters are improved by using the digital control algorithm based on delta-operator without increasing the hardware circuit scale. The design method of voltage compensator in delta-domain using PID (Proportion-Integration- Differentiation) control is given in this paper, and the simulation results based on Simulink platform are provided, which have verified the theoretical analysis results very well. It can be concluded that, the presented control algorithm based on delta-operator has better stability and controlling accuracy, and easier hardware implementation than the existed control algorithms based on z-operator, therefore it can be used for the voltage compensator design in high-frequency digitally- controlled DC-DC switching converters.

Keywords: Digitally-controlled DC-DC switching converter, finite word length, control algorithm based on delta-operator, high-frequency, stability.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1127354

References:

[1] C. Shi., B. C., Walker., et al., "A highly integrated power management IC for advanced mobile applications," IEEE Journal of Solid-State Circuits, vol. 42, pp. 1723-1731, 2007.
[2] Tao Zhou; Jianping Xu; Francois, B., "Analog-to-digital converter architectures for digital controller of high-frequency power converters," IEEE Industrial Electronics, IECON 2006 - 32nd Annual Conference on, pp.2471-2476, Nov. 2006.
[3] M. F. N. Tajuddin, N. A. Rahim, I. Daut, et al., "State space averaging technique of power converter with digital PID controller," in TENCON 2009 - 2009 IEEE Region 10 Conference, pp. 1-6, 2009.
[4] F. Kurokawa, Y. Maeda, Y. Shibata, et al., "A new fast digital PID control dc-dc converter," in Power Electronics and Motion Control Conference (EPE/PEMC), 2010 14th International, pp. S13-15-S13-19, 2010.
[5] Qian Long-jun, Guo Zhi, “On Satisfactory Control of Continuous Time Systems with Delta Operator induced Discrete Models”, Control and Decision, Dec. 2005.
[6] Ji Zhi-cheng, Zhao Wei-yi, Xie Lin-Bo, “Optimal Control of Networked Control System Using DOperator”, Control and Decision, Vol. 21 No. 12, Dec. 2006
[7] Hori. N, Mori. T, “A New Perspective for Discrete Time Models of a Continuous Time System,” IEEE Trans. Automat. Contr., 1992, AC-37 (7: 1013-1017).
[8] Permaratne. K, July. K. I, “tabular Method for Determining Root Distribution of Delta Operator Formulated Real Polynomials,” IEEE Tran. Automat. Contr., 1994, AC-39(2): pp. 352-355.
[9] Li Hui-guang, Wu Bo, Li Guo-you, et al. Delta operator control and its robust control theory basis (M). Beijing: National Defense Industry Press, 2005.
[10] M iddleton R H, Goodwin G C. Improved Finite Word Length Characteristics in Digital Control Using Delta Operators (J). IEEE T rans on Automatic Control, 1986, 31(11): 1015-1021.
[11] Middleton R H, Goodwin G C. Digital Control and Estimation: A Unified Approach (M). NJ: Prentice Hall, 1990