Fast frequency response measurement of switched-mode Converters in the presence of nonlinear distortions

Switched-mode converters have become extensively used in powering different consumer products. The increased mass production using low-cost components with high parameter variation has set new challenges to designers. Recent studies have shown that frequency-domain characterization yields most useful information about the dynamics and quality of the converter. This has been widely recognized and fast correlation techniques have been developed to make appropriate frequency response measurement to be applied both in design and production phases. These techniques are based on appropriate broad-band excitation signal which is injected into a converter and its response is measured and analyzed. All the previous papers have used pseudo-random binary sequence (PRBS) as the excitation. The conventional binary sequence do not, however, suit well for the processes suffering from strong non-linear distortions. This paper proposes a new type of excitation signal which can be used similarly to the conventional PRBS but provides much more accurate frequency response estimates. Inverse-repeat binary sequence (IRS) is applied to minimize the effect of different nonlinearities and the frequency response is measured by means of spectrum method. The method is verified both with simulation and practical measurements and the results are compared to the conventional PRBS technique.

[1]  Teuvo Suntio,et al.  Load-imposed instability and performance degradation in a regulated converter , 2006 .

[2]  John Vanderkooy,et al.  Transfer-Function Measurement with Maximum-Length Sequences , 1989 .

[3]  Keith R. Godfrey,et al.  Perturbation signals for system identification , 1993 .

[4]  Solomon W. Golomb,et al.  Shift Register Sequences , 1981 .

[5]  D. Maksimović,et al.  Modeling of Quantization Effects in Digitally Controlled DC–DC Converters , 2007 .

[6]  D. Maksimovic,et al.  Integration of Frequency Response Measurement Capabilities in Digital Controllers for DC–DC Converters , 2008, IEEE Transactions on Power Electronics.

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

[8]  D. Maksimovic,et al.  System identification of power converters with digital control through cross-correlation methods , 2005, IEEE Transactions on Power Electronics.

[9]  George C. Verghese,et al.  Aliasing effects in PWM power converters , 1999, 30th Annual IEEE Power Electronics Specialists Conference. Record. (Cat. No.99CH36321).

[10]  Milan M. Jovanovic,et al.  Analysis and design of self-oscillating flyback converter , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[11]  Teuvo Suntio,et al.  Analysing the dynamics of regulated converters , 2006 .

[12]  D. Maksimovic,et al.  A modified cross-correlation method for system identification of power converters with digital control , 2004, 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551).

[13]  E. Santi,et al.  Improved online identification of switching converters using digital network analyzer techniques , 2008, 2008 IEEE Power Electronics Specialists Conference.

[14]  A. Sánchez.  Modern control systems, 9th edition, Richard C. Dorf and Robert H. Bishop, Prentice‐Hall, Upper Saddle River, NJ, 2001, 831 pages, ISBN 0‐13‐030660‐6 , 2006 .

[15]  David Rees,et al.  ic Signals for Measuring , 1996 .

[16]  Tomi Roinila,et al.  Circular correlation based identification of switching power converter with uncertainty analysis using fuzzy density approach , 2009, Simul. Model. Pract. Theory.

[17]  W. D. T. Davies,et al.  System identification for self-adaptive control , 1970 .

[18]  J.S. Baras,et al.  Multiple Sampling for Estimation on a Finite Horizon , 2006, Proceedings of the 45th IEEE Conference on Decision and Control.

[19]  Marian K. Kazimierczuk,et al.  Open loop small-signal control-to-output transfer function of PWM buck converter for CCM: modeling and measurements , 1996, Proceedings of 8th Mediterranean Electrotechnical Conference on Industrial Applications in Power Systems, Computer Science and Telecommunications (MELECON 96).