Design and prototyping of control grid power supply based on resonant converter for RF amplifier

Abstract

This paper includes a detailed study of Zero Voltage Switching resonant converter based buck converter, understanding with the help of mathematical equations for various modes and simulation of DC Power source at different voltages and current level. As in conventional pulse width modulated (PWM) power converters, power switches have to cut off the load current within the turn-on and turn-off times under the hard switching conditions. The concept of resonant converter is to incorporate resonant tanks in the converters to create oscillatory (usually sinusoidal) voltage and/or current waveforms so that zero-voltage switching (ZVS) or zero-current switching (ZCS) conditions can be created for the power switches. The reduction of switching loss and the continual improvement of power switches allow the switching frequency of the resonant converters to reach hundreds of kilo-Hertz. Consequently, the size of magnetic components can be reduced and the power density of the converters increased. The underlying principle is to replace the power switch in PWM converters with the resonant switch. A simulation study in PSim software was carried out for 500V DC, 4A model. The design of resonant tank circuit is an important aspect of the converter as it forms the backbone of the complete system and basis of selection of other important parameters as well hence mathematical model analysis with the help of circuit equations for various modes have been shown as a part of selection criteria.