Self-sustained oscillating resonant converters operating above theresonant frequency

摘要

This paper presents a new control technique for resonantnconverters. Unlike conventional variable frequency control whichnexternally imposes the switching frequency, the proposed scheme is basednon controlling the displacement angle between one of the resonantncircuit variables, typically the current through the resonant inductor,nand the voltage at the output of the inverter. As a result, zero-voltagenswitching (ZVS) can be ensured over a wide operating range. The proposedncontrol technique cam be applied for series, parallel, andnseries-parallel resonant converters. As an example, the staticncharacteristics and dynamic model of a series-parallel resonantnconverter with the proposed controller are derived and the systemnbehaviour is investigated in detail. Experimental results are given tondemonstrate the operation of resonant converters with the proposedncontroller and to validate the analysis