Novel Control Methods Applied to a Series Loaded Resonant Converter

Abstract

Load resonant converter topologies are very popular and used to increase circuit switching speeds, allowing the cost of circuit magnetics to be reduced, while still keeping switching losses to a minimum. In this paper a new open loop and close loop control method for 2.1 kW Series Loaded Resonant DC-DC converter operated in above resonant mode is presented. A voltage controlled oscillator (VCO) is used to regulate the DC output voltage of converter in open loop. The control circuit used to regulate the output voltage of SLR converter is frequency modulation technique in which switching frequency of the converter is varied to regulate the output voltage. The close loop variable frequency control mainly consists of feedback loop and PI regulator with VCO. VCO is a voltage-to-frequency converter used to convert error in output voltage in change of frequency to control the voltage in close loop system. The simulation results for both open loop and close loop control methods are also presented in this paper to verify the control concept.