Accurate sliding-mode control system modeling for buck converters
- 1 January 2007
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
Abstract
This paper shows that classical sliding mode theory fails to correctly predict the output impedance of the highly useful sliding mode PID compensated buck converter. The reason for this is identified as the assumption of the sliding variable being held at zero during sliding mode, effectively modeling the hysteretic comparator as an infinite gain. Correct prediction of output impedance is shown to be enabled by the use of a more elaborate, finite-gain model of the hysteretic comparator, which takes the effects of time delay and finite switching frequency into account. The demonstrated modeling approach also predicts the self-oscillating switching action of the sliding-mode control system correctly. Analytical findings are verified by simulation as well as experimentally in a 10-30 V/3A buck converter.Keywords
This publication has 7 references indexed in Scilit:
- Ultrafast Tracking Power Supply With Fourth-Order Output Filter and Fixed-Frequency Hysteretic ControlIEEE Transactions on Power Electronics, 2008
- Sliding-Mode Control Design of a Boost–Buck Switching Converter for AC Signal GenerationIEEE Transactions on Circuits and Systems I: Regular Papers, 2004
- Simple PWM modulator topology with excellent dynamic behaviorPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2004
- A ripple control buck regulator with fixed output frequencyIEEE Power Electronics Letters, 2003
- Generation of signals in a buck converter with sliding mode controlPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Describing-function analysis of a ripple regulator with slew-rate limits and time delaysPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Small-signal analysis of DC-DC converters with sliding mode controlIEEE Transactions on Power Electronics, 1997