Digital LQR steady-state optimal control with feedforward for nonminimum phase boost DC-DC converter

This paper presents a perfect optimal control for nonminimum phase boost DC-DC converters by adopting a combination of feedback and feedforward controller. A linear quadratic regulator (LQR) feedback controller is firstly designed and proposed to have the following improvements. Firstly, integral control by state augmentation is adopted in order to and eliminate the steady-state errors. Secondly, feedback gain and estimator gain are calculated offline based on LQR steady-state optimal control method and steady-state Kalman filter. Then, the problems of integral wind-up protection is also handled. A feedforward controller is then proposed to eliminate the phase error caused by right half phase zero (RHPZ) emerged in nonminimum phase of boost DC-DC converters. The feedforward controller is implemented by zero phase error tracking control (ZPETC) technique because the inverse of nonminimum phase system is unstable. Finally, the proposed controller has been implemented on NI CompactRio platform for boost converter voltage control. The experimental results clearly show the proposed controller offers better performance as compared to conventional digital compensation controller.

[1]  F.H.F. Leung,et al.  The control of switching DC-DC converters-a general LWR problem , 1991 .

[2]  Abraham Pressman,et al.  Switching Power Supply Design , 1997 .

[3]  Regan,et al.  Advances in Digital Control for High-frequency Switched-mode Power Converters , 2010 .

[4]  J. Fernando A. da Silva,et al.  Digital LQR control with Kalman Estimator for DC-DC Buck converter , 2011, 2011 IEEE EUROCON - International Conference on Computer as a Tool.

[5]  J. M. Dores Costa.  Design of linear quadratic regulators for quasi-resonant DC-DC converters , 2001, PESC 2001.

[6]  J. Pou,et al.  A Linear-Quadratic Regulator with Integral Action Applied to PWM DC-DC Converters , 2006, IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics.

[7]  Teuvo Suntio,et al.  Dynamic Profile of Switched-Mode Converter , 2009 .

[8]  L.Y. Pao,et al.  Model Inversion Architectures for Settle Time Applications with Uncertainty , 2006, Proceedings of the 45th IEEE Conference on Decision and Control.

[9]  Masayoshi Tomizuka,et al.  Zero Phase Error Tracking Algorithm for Digital Control , 1987 .

[10]  Paolo Mattavelli,et al.  Digital Control in Power Electronics , 2006, Digital Control in Power Electronics.

[11]  J. Álvarez-Ramírez,et al.  A stable design of PI control for DC-DC converters with an RHS zero , 2001 .

[12]  Hebertt Sira-Ramírez,et al.  Control Design Techniques in Power Electronics Devices , 2006 .

[13]  Tore Hägglund,et al.  Advanced PID Control , 2005 .

[14]  D. Maksimovic,et al.  Small-signal Discrete-time Modeling of Digitally Controlled DC-DC Converters , 2006, 2006 IEEE Workshops on Computers in Power Electronics.

[15]  H. Jin,et al.  Digital controller design for switchmode power converters , 1999, APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285).

[16]  R. M. Bass,et al.  Control structure optimization of a boost converter: an LQR approach , 1997, PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing and Electronic Specialists Conference 1972.

[17]  T. W. Martin,et al.  Digital control for switching converters , 1995, 1995 Proceedings of the IEEE International Symposium on Industrial Electronics.

[18]  J.H. Lee,et al.  Digital State Feedback Current Control using Pole Placement Technique for the 42V/14V Bi-Directional DC-DC Converter Application , 2007, APEC 07 - Twenty-Second Annual IEEE Applied Power Electronics Conference and Exposition.

[19]  Jan Swevers,et al.  Robust Perfect Tracking Control With Discrete Sliding Mode Controller , 2003 .