Small-signal modeling and control of the quasi-square-wave boostconverter

摘要

Sampled-data techniques are used to examine the dynamicncharacteristics and closed-loop performance of the quasi-square-wavenboost converter. Direct duty-ratio control and current-mode control arenconsidered. With direct duty-ratio control, the system poles remain wellndamped under all load conditions, and there is no zero in thencontrol-to-output transfer function. Good closed-loop performance isntherefore achieved. Under current-mode control, the requirement for anstabilizing ramp is seen to depend on load conditions, and thenachievable voltage control-loop bandwidth is smaller than that usingndirect duty-ratio control; however, there is a significant reduction innthe magnitude of the DC source to output-voltage frequencynresponse