Unified average and small-signal modeling of direct-on-time control

A unified and consistent method for the average and small-signal modeling of switched-mode converters under direct-on-time (DOT) or voltage mode (VM) control applicable to fixed- and variable-frequency operation in discontinuous (DCM) and continuous (CCM) modes of operation is proposed. The method is based on the direct estimation of the state-variable derivatives using their physical and circuit theoretical dependence on the corresponding circuit elements. This has been the first time that it has been explicitly recognized that the time-varying local average value of the inductor current is the state variable instead of the instantaneous current being also continuous within a cycle regardless of the operation mode. The method provides a common basis for the average modeling of VM control and leads eventually to the well-recognized results obtained using state-space averaging (SSA) in CCM or its modified version in DCM under fixed-frequency operation as well as accurate full-order models also in the variable-frequency operation. In addition, the method known as unterminated modeling is introduced, providing a useful tool for the dynamic analysis of switched-mode converters.

[1]  George C. Verghese,et al.  Modeling and simulation of power electronic converters , 2001, Proc. IEEE.

[2]  Slobodan Cuk,et al.  A general unified approach to modelling switching DC-tO-DC converters in discontinuous conduction mode , 1977, 1977 IEEE Power Electronics Specialists Conference.

[3]  Dragan Maksimovic,et al.  A unified analysis of PWM converters in discontinuous modes , 1991 .

[4]  T. Suntio,et al.  Small-signal modeling for design of robust variable-frequency flyback battery chargers for portable device applications , 2001, APEC 2001. Sixteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.01CH37181).

[5]  Sung-Soo Hong,et al.  Modeling and small-signal analysis of controlled on-time boost power factor correction circuit , 2000, Proceedings IPEMC 2000. Third International Power Electronics and Motion Control Conference (IEEE Cat. No.00EX435).

[6]  D. Tagliavia,et al.  DC-DC flyback converters in the critical conduction mode: a re-examination , 2000, Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129).

[7]  Y. Panov,et al.  Small-signal model of variable-frequency flyback converter , 2003, Eighteenth Annual IEEE Applied Power Electronics Conference and Exposition, 2003. APEC '03..

[8]  Teuvo Suntio.  Small-signal modeling of switched-mode converters under direct-on-time control-a unified approach , 2002, IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02.

[9]  V. Vorperian.  Simplified analysis of PWM converters using model of PWM switch. II. Discontinuous conduction mode , 1990 .

[10]  P. Silventoinen,et al.  Analysis and small-signal modeling of self-oscillating converters with applied switching delay , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[11]  Dragan Maksimovic,et al.  Computer-aided small-signal analysis based on impulse response of DC/DC switching power converters , 2000 .

[12]  R. D. Middlebrook.  Small-signal modeling of pulse-width modulated switched-mode power converters , 1988 .

[13]  R. D. Middlebrook,et al.  Low-frequency characterization of switched DC-DC converters , 1972 .

[14]  R. Redl,et al.  Dynamic analysis of switching-mode DC/DC converters , 1991 .

[15]  Jian Sun,et al.  Averaged modeling of PWM converters operating in discontinuous conduction mode , 2001 .

[16]  D. Maksimović,et al.  Averaged switch modeling of boundary conduction mode DC-to-DC converters , 2001, IECON'01. 27th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.37243).

[17]  R. M. Bass,et al.  On the use of averaging for the analysis of power electronic systems , 1989, 20th Annual IEEE Power Electronics Specialists Conference.

[18]  Teuvo Suntio,et al.  Use of unterminated two-port modeling technique in analysis of input filter interactions in telecom DPS systems , 2002, 24th Annual International Telecommunications Energy Conference.

[19]  Slobodan Cuk,et al.  A general unified approach to modelling switching-converter power stages , 1977 .

[20]  Robert W. Erickson,et al.  Fundamentals of Power Electronics , 2001 .