Integral cycle mode control of the series resonant converter

Abstract

A control method for the series resonant converter (SRC) in which the device switching instants are always synchronized to the zero-crossing points of the resonant current is proposed. Output voltage is controlled by proper selection of the switch modes by varying the duty ratio of the powering mode and free resonant mode. Each switch mode is analyzed and the DC transfer function is obtained. It is also shown that the simulation results coincide well with the practical case. The SRC using the proposed control scheme shows many advantages, such as low current-switching stress, low switching loss, low electromagnetic interference, high input power factor, and wide control range. Some of these characteristics are verified experimentally.