Quasi resonant converter for autonomous power supply

Quasiresonant converters (QRCs) are increasingly being used in autonomous power supply systems. These converters are efficient, have small dimensions, and operate stably when the load changes. This study is devoted to the development of a zero-current switching QRC with improved characteristics. The main advantages of this QRC are a wide range of regulation and a low level of output voltage ripple. These advantages are achieved by the recuperation of excess energy due to a transistor shunting the primary winding of a transformer. In this work, a mathematical model of advanced QRC (AQRC) is developed, and the quantitative relationship between the parameters of the AQRC power circuit elements is established. In addition, the electromagnetic processes occurring in the AQRC are studied on the Simulink model. Moreover, the AQRC characteristics for various operating modes are studied, and the rational parameters of its components are determined. Then, an AQRC prototype is created. The tests of the prototype are in good agreement with the models. Results show that the AQRC allows for the adjustment of the output voltage ranging from 0 to 100% of the rated value and has a standard level of electromagnetic compatibility.

Automated summary

Quasiresonant converters are efficient and stable with small dimensions, with the main advantages of a wide range of regulation and low output voltage ripple achieved by energy recuperation. The development of a mathematical model and analysis on electromagnetic processes in the AQRC demonstrates adjustability in output voltage and standard electromagnetic compatibility.