Singular Perturbation Theory for DC-DC Converters and Application to PFC Converters
Many control schemes for dc-dc converters begin with the assertion that inductor currents are "fast" states and capacitor voltages are "slow" states. This assertion must be true for power factor correction (PFC) converters to allow independent control of current and voltage, and is important for many other applications. In the present study, singular perturbation theory is applied to two-state switching-power converters to provide rigorous justification of the timescale separation. Krylov-Bogoliubov-Mitropolsky averaging is used to include switching ripple effects. A relationship between inductance, capacitance, load resistance, and loss resistances derives from an analysis of the off-manifold dynamics of an approximate model. Similar results hold for boost, buck, and buck-boost converters. Experimental boost converters validate the results. Discrete-time analysis is also shown. Simulated PFC converters demonstrate a simple, sensorless control technique that requires timescale separation.
J. W. Kimball and P. T. Krein, "Singular Perturbation Theory for DC-DC Converters and Application to PFC Converters," IEEE Transactions on Power Electronics, vol. 23, no. 6, pp. 2970-2981, Institute of Electrical and Electronics Engineers (IEEE), Nov 2008.
The definitive version is available at http://dx.doi.org/10.1109/TPEL.2008.2004272
Electrical and Computer Engineering
National Science Foundation (U.S.)
Keywords and Phrases
Averaging; Integral Manifold; Power Factor Correction (PFC); Singular Perturbation; Stability; Capacitors; Voltage Control; Inductors; Pulse Width Modulation; Switching Converters; Sensorless Control; Current Control; Inductance; Capacitance; Switching Convertors; DC-DC Power Convertors; Discrete Time Systems; Singularly Perturbed Systems
International Standard Serial Number (ISSN)
Article - Journal
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