Fixed-Frequency Boundary Control of Buck Converter With Second-Order Switching Surface

This paper presents a fixed-frequency boundary control of buck converters. The method is based on integrating the concept of variable hysteresis into the boundary control technique with second-order switching surface. The switching frequency is maintained constant over a wide range of supply voltages and output loads. The method is based on using a frequency-to-voltage converter and comparing its output voltage with a reference voltage to control the width of the hysteresis in the boundary controller. It also combines the advantages of the boundary control that the converter can reach the steady state in two switching actions after large-signal disturbances. The basic operating principles, stability analysis, and design procedures will be given. The proposed control method has been successfully applied to control a 140 W, 24 V/12 V buck converter. The steady-state characteristics, including the switching frequency and output voltage ripple, at different input voltages and output loads with and without the proposed control method have been compared. The system responses under large-signal supply voltage and load disturbances will be discussed.

[1]  Henry Shu-hung Chung,et al.  A Comparative Study of Boundary Control With First- and Second-Order Switching Surfaces for Buck Converters Operating in DCM , 2007, IEEE Transactions on Power Electronics.

[2]  Paolo Tenti,et al.  A novel hysteresis control method for current-controlled voltage-source PWM inverters with constant modulation frequency , 1990 .

[3]  M.T. Iqbal,et al.  Advanced boundary control of inverters using the natural switching surface: Normalized geometrical derivation , 2008, 2008 IEEE Power Electronics Specialists Conference.

[4]  Jiin-Chuan Wu,et al.  A ripple control buck regulator with fixed output frequency , 2003 .

[5]  George C. Verghese,et al.  Nonlinear Phenomena in Power Electronics , 2001 .

[6]  Daniel W. Hart,et al.  Power Electronics , 2010 .

[7]  H. Shu-hung Chung,et al.  High-Order Switching Surface in Boundary Control of Inverters , 2007, IEEE Transactions on Power Electronics.

[8]  Y. Cheron,et al.  Fixed-frequency sliding mode control of a single-phase voltage source inverter with input filter , 1996, Proceedings of IEEE International Symposium on Industrial Electronics.

[9]  John E. Quaicoe,et al.  Selection of a curved switching surface for buck converters , 2006, IEEE Transactions on Power Electronics.

[10]  C. K. Michael Tse,et al.  A unified approach to the design of PWM-based sliding-mode voltage controllers for basic DC-DC converters in continuous conduction mode , 2006, IEEE Transactions on Circuits and Systems I: Regular Papers.

[11]  Yan-Fei Liu,et al.  An Optimal Control Method for Buck ConvertersUsing a Practical Capacitor ChargeBalance Technique , 2008, IEEE Transactions on Power Electronics.

[12]  Paolo Tomasin,et al.  Improved constant-frequency hysteresis current control of VSI inverters with simple feed-forward bandwidth prediction , 1995, IAS '95. Conference Record of the 1995 IEEE Industry Applications Conference Thirtieth IAS Annual Meeting.

[13]  A. Prodic,et al.  Continuous-Time Digital Controller for High-Frequency DC-DC Converters , 2008, IEEE Transactions on Power Electronics.

[14]  M. Marchesoni,et al.  Experimental study of a power conditioning system using sliding mode control , 1996 .

[15]  G. Verghese,et al.  Nonlinear phenomena in power electronics : attractors, bifurcations, chaos, and nonlinear control , 2001 .

[16]  V. Yousefzadeh,et al.  Proximate Time-Optimal Digital Control for Synchronous Buck DC–DC Converters , 2008, IEEE Transactions on Power Electronics.

[17]  P. Krein,et al.  Issues in Boundary Control , 1996 .

[18]  J. M. Ruiz,et al.  Minimal UPS structure with sliding mode control and adaptive hysteresis band , 1990, [Proceedings] IECON '90: 16th Annual Conference of IEEE Industrial Electronics Society.

[19]  H. Chung,et al.  A Comparative Study of the Boundary Control of Buck Converters Using First- and Second-Order Switching Surfaces -Part I: Continuous Conduction Mode , 2005, 2005 IEEE 36th Power Electronics Specialists Conference.

[20]  C.K. Tse,et al.  A fixed-frequency pulsewidth modulation based quasi-sliding-mode controller for buck converters , 2005, IEEE Transactions on Power Electronics.

[21]  K.K.S. Leung,et al.  A Comparative Study of the Boundary Control of Buck Converters Using First- and Second-Order Switching Surfaces -Part II: Discontinuous Conduction Mode , 2005, 2005 IEEE 36th Power Electronics Specialists Conference.

[22]  K.K.S. Leung,et al.  Derivation of a second-order switching surface in the boundary control of buck converters , 2004, IEEE Power Electronics Letters.

[23]  J.F. Silva,et al.  Fixed frequency sliding mode modulator for current mode PWM inverters , 1993, Proceedings of IEEE Power Electronics Specialist Conference - PESC '93.

[24]  P. Krein,et al.  Issues in boundary control [of power convertors] , 1996, PESC Record. 27th Annual IEEE Power Electronics Specialists Conference.

[25]  B. R. Menezes,et al.  Analysis of switching frequency reduction methods applied to sliding mode controlled DC-DC converters , 1992, [Proceedings] APEC '92 Seventh Annual Applied Power Electronics Conference and Exposition.

[26]  Longya Xu,et al.  Sliding Mode Pulsewidth Modulation , 2008, IEEE Transactions on Power Electronics.

[27]  Siew-Chong Tan,et al.  Indirect Sliding Mode Control of Power Converters Via Double Integral Sliding Surface , 2008, IEEE Transactions on Power Electronics.

[28]  M. F. Greuel,et al.  Design approaches to boundary controllers , 1997, PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing and Electronic Specialists Conference 1972.

[29]  M. Castilla,et al.  Feedback Linearization of a Single-Phase Active Power Filter via Sliding Mode Control , 2008, IEEE Transactions on Power Electronics.