PWM Converters

This research has followed several directions; selected published results are summarized below.

Modeling, control, and design of PWM power converters

  1. Robert Erickson, Slobodan Cuk, and R. D. Middlebrook, "Large Signal Analysis and Design of Switching Regulators," IEEE Power Electronics Specialists Conference, 1982 Record, pp. 240-250.
    State-plane analysis of nonlinear switching regulators having state feedback. Solution for equilibrium points, and the effects of saturation and current limiting.

  2. A series of equivalent circuits models that show a second harmonic in a boost amplifier

    A series of equivalent circuits models the dc, fundamental, second harmonic, and higher harmonics in a boost amplifier.

    Robert Erickson and R. D. Middlebrook,  Proceedings Fourth Annual International PCI '82 Conference, pp. 567-582, March 1982.
    A perturbation series analysis is employed to predict harmonic distortion in switching amplifiers. This leads to a series of equivalent circuits that predict approximate magnitudes and phases of each harmonic.
  3. Robert Erickson, Bill Behen, R. D. Middlebrook, and Slobodan Cuk, "Characterization of Power MOSFET's in Switching Converters," Proceedings Seventh National Solid-State Power Conversion Conference (Powercon 7), pp. D4.1-D4.17, March 1980.
  4. Slobodan Cuk and Robert Erickson, "A Conceptually New High-Frequency Switched-Mode Amplifier Technique Eliminates Current Ripple," Proceedings Fifth National Solid-State Power Conversion Conference (Powercon 5), pp. G3.1-G3.22, May 1978.
  5. Robert Erickson,  IEEE Power Electronics Specialists Conference, 1983 Record, pp. 9-22.
    The first paper on systematic systhesis of switched-mode converter topologies. Additional papers on converter synthesis are listed on the rectifier page.
  6. I. Horowitz, M. Sidi, and R. Erickson, "Quantitative Feedback Synthesis for Nonlinear Switched-Mode Uncertain Regulators," International Journal of Electronics, Vol. 57, No. 4, pp. 461-476, Oct. 1984.
  7. I. Khan and R. W. Erickson, "Control of Switched-Mode Converter Harmonic-Free Terminal Waveforms through Internal Energy Storage," IEEE Power Electronics Specialists Conference, 1986 Record, pp. 13-26, June 1986.
  8. Yungtaek Jang and Robert Erickson,  IEEE Applied Power Electronics Conference, 1991 Record, March 1991.
  9. Yungtaek Jang and Robert Erickson, "Physical Origins of Input Filter Oscillations in Current Programmed Converters," IEEE Transactions on Power Electronics, vol 7, no. 4, pp. 725-733, October 1992.

  10. addition of an input filter to a switching power converter, where power is made into a parallel circuit with a power source on the side of the filter

    Addition of an input filter to a switching power converter.

    R. Erickson,  IEEE Applied Power Electronics Conference, March 1999.
    This paper extends Middlebrook's original work on optimum damping of input filters to several additional cases. This material was later incorporated into the textbook chapter on input filter damping.
  11. R. Erickson, “DC-DC Power Converters,” article in Wiley Encyclopedia of Electrical and Electronics Engineering, vol. 5, pp. 53-63, 1999.
  12. J. Chen, R. Erickson, and D. Maksimovic, "Averaged Switch Modeling of Boundary Conduction Mode DC-to-DC Converters," Proc. IEEE Industrial Electronics Society Annual Conference (IECON 01), Nov. 2001.
  13. A. Prodic, D. Maksimovic, and R. Erickson, "Design and Implementation of a Digital PWM Controller for a High- Frequency Switching DC-to-DC Power Converter," Proc. IEEE Industrial Electronics Society Annual Conference (IECON 01), Nov. 2001.
  14. P. Athalye, D. Maksimovic, and R. Erickson, "Averaged Switch Modeling of Active-Clamped Converters," Proc. IEEE Industrial Electronics Society Annual Conference (IECON 01), Nov. 2001.
  15. Y. Zhang, R. Zane, A. Prodic, R. Erickson, and D. Maksimovic, "Online Calibration of MOSFET On-State Resistance For Precise Current Sensing," IEEE Power Electronics Letters, vol. 2, no. 3, pp. 100-103, September 2004.
  16. P. Athalye, D. Maksimovic, and R. Erickson, "Variable-Frequency Predictive Digital Current Mode Control," IEEE Power Electronics Letters, vol. 2, no. 4, pp. 113-116, December 2004.
  17. D. Maksimović, R. Zane, R. Erickson, “Advances in practical high-performance digital control,” invited paper, Digital Power Forum, September 2005.
  18. D. Friedrichs, R. Erickson, and J. Gilbert, “A New System Architecture Improves Output Power Regulation in Electrosurgical Generators,” 33rd Annual International IEEE Engineering In Medicine and Biology Society Conference, Aug. 2011.
  19. Robert W. Erickson,  SOBRAEP/IEEE Fourth Brazilian Power Electronics Conference, December 1997, invited paper and tutorial seminar.
  20. Dragan Maksimovic and Robert Erickson,  IEEE Power Electronics Specialists Conference, 1999, tutorial seminar.
  21. Robert Erickson and Dragan Maksimovic, IEEE Applied Power Electronics Confernce, March 2003, tutorial seminar.
  22. R. White, G. Miller, B. Dudman, and R. Erickson, "Recent Developments in GaAs Power Switching Devices Including Device Modeling," IEEE Applied Power Electronics Conference, March 2014.

Magnetics modeling

Winding geometry of four power sources that have a current running through them, where the bottom two are going into the screen, and the top two are coming out
This series of papers is concerned with modeling switching converter waveforms in multiple-winding transformers and coupled-inductors. It specifically addresses prediction of cross-regulation in multiple-output flyback converters, a problem previously considered intractable. An approach is found in which every model parameter can be directly measured in the laboratory, and that explains the observed waveforms and converter performance.

  1. Transformer of a three-output flyback converter. Top: winding geometry. Bottom: an equivalent circuit model that can be directly measured and that predicts the observed cross-regulation performance.

    Transformer of a three-output flyback converter. Top: winding geometry. Bottom: an equivalent circuit model that can be directly measured and that predicts the observed cross-regulation performance.

    K. Changtong, R. Erickson, and D. Maksimovic,  IEEE Power Electronics Specialists Conference, June 2001.
    The ladder model of multiple-winding transformers has been employed by multiple authors, based on the physical geometry of the windings. It is shown here that this model does not predict the first-order behavior of multiple-output flyback converters: regardless of the winding geometry, a full-order model is required. The extended cantilever model correctly predicts observed waveforms and gives a physical explanation of the relevant phenomena.
  2. R. Erickson and D. Maksimovic,  IEEE Applied Power Electronics Conference, March 1999, tutorial seminar.
  3. D. Maksimovic and R. Erickson,  IEEE Applied Power Electronics Conference, March 1999.
    This paper applies the multiple-winding magnetics models of other papers listed here, to the difficult problem of predicting cross-regulation in multiple-output flyback converters. These converters are notorious for exhibiting very poor cross-regulation. This paper explains how winding geometry governs cross-regulation, and it suggests solutions to improve cross regulation.
  4. R. Erickson and D. Maksimovic,  IEEE Power Electronics Specialists Conference, May 1998.
    This paper describes the modeling of the flyback transformer of a multiple-output flyback converter, with a methodology in which every model parameter is directly measured in the laboratory. The resulting model is shown to accurately predict converter waveforms and cross-regulation performance.
  5. D. Maksimovic, R. Erickson, and C. Griesbach, “Modeling of Cross-Regulation in Converters Containing Coupled Inductors,” IEEE Applied Power Electronics Conference, pp. 350-356, Feb. 1998.
  6. D. Maksimovic, R. Erickson, and C. Griesbach,  IEEE Transactions on Power Electronics, vol. 15, no. 4, pp. 607-615, July 2000.

Power conservative networks

While it has been well understood that the transformer and gyrator are the only linear power-conservative two-port networks, in the power electronics field we have found applications that require new nonlinear power-conservative systems. These papers explore the fundamentals of these networks. The dependent power source and sink are basic nonlinear elements that arise in the models of these systems whenever buffering conditions are met. The loss-free resistor is a power-conservative network that arises in a number of applications including low-harmonic rectification and DCM converters.

  1. Loss-Free Resistor power conservative network. The LFR is comprised of an effective resistor and a dependent power source.

    Properties of the ideal rectifier are modeled by the Loss-Free Resistor power conservative network. The LFR is comprised of an effective resistor and a dependent power source.

    S. Singer and R. Erickson, “On the buffering condition implied by the stabilization of the output of switched-mode converters,” IEEE Power Electronics Specialists Conference, 1992 Record, pp. 1197-1201, vol. 2, June 1992.
  2. S. Singer and R. Erickson, “Control-implied input/output buffering of power conservative two-port networks,” IEEE International Symposium on Circuits and Systems (ISCAS ’92), pp. 1911-1913, vol. 4, 1992.
  3. S. Singer and R.W. Erickson,  IEE Proceedings - Circuits Devices and Systems, vol. 141, no. 3, pp. 220-226, June 1994.
  4. S. Singer and R. Erickson,  IEEE Transactions on Power Electronics, vol. 7, no. 1, January 1992.