Time-varying effects and averaging issues in models for current-mode control

This paper investigates issues in modeling of current-mode control in converters. The effects of the current-sampling intrinsic to current-mode control are analyzed, and inadequately recognized limitations of linear time-invariant (LTI) models at high frequencies (where the system behavior is time-varying) are exposed. The paper also examines the geometric methods used to derive duty-ratio constraints in averaged models of current-mode control and points out the sources of discrepancies among various models. The conclusions are supported by simulation and experimental results.

[1]  R.D. Middlebrook,et al.  Topics in multiple-loop regulators and current-mode programming , 1985, 1985 IEEE Power Electronics Specialists Conference.

[2]  Jesse E. Chen,et al.  A refined nonlinear averaged model for constant frequency current mode controlled PWM converters , 1991 .

[3]  R. D. Middlebrook,et al.  Unified modeling and measurement of current-programmed converters , 1993, Proceedings of IEEE Power Electronics Specialist Conference - PESC '93.

[4]  F. D. Tan,et al.  A unified model for current-programmed converters , 1995 .

[5]  R. B. Ridley,et al.  A new, continuous-time model for current-mode control (power convertors) , 1991 .

[6]  R. Tymerski,et al.  State space models for current programmed pulse width modulated converters , 1992 .

[7]  G. Verghese,et al.  Averaged and sampled-data models for current mode control: a re-examination , 1989, 20th Annual IEEE Power Electronics Specialists Conference.

[8]  George C. Verghese,et al.  Principles of Power Electronics , 2023 .

[9]  R. Tymerski.  Application of the time varying transfer function for exact small-signal analysis , 1991 .

[10]  B. Anderson,et al.  Digital control of dynamic systems , 1981, IEEE Transactions on Acoustics, Speech, and Signal Processing.

[11]  George C. Verghese,et al.  Time-varying effects in models for current-mode control , 1995, Proceedings of PESC '95 - Power Electronics Specialist Conference.

[12]  R.D. Middlebrook,et al.  Modelling and analysis of switching DC-to-DC converters in constant-frequency current-programmed mode , 1979, 1979 IEEE Power Electronics Specialists Conference.