A novel single-switch series resonant converter for low power DC/DC energy conversion applications

This work develops a novel single-switch series resonant converter for low power DC/DC energy conversion applications. The circuit topology integrates a class-D series resonant converter and class-E resonant inverter. The converter uses only one active power switch to reduce the cost of the active switches and control circuits. With a simple circuit configuration and few components, the desired highly efficient circuit performance is realized. The active switch is controlled by pulse width modulation (PWM) at a fixed switching frequency with a constant duty cycle. The operating equations of the novel single-switch series converter are analyzed, and performance characteristics are presented. With carefully designed circuit parameters, the active power switch can be operated under the zero-voltage-switching (ZVS) condition, leading to a high circuit efficiency. A prototype circuit designed for a 20Ω load is built and tested to verify the theoretical predictions. The measured maximum energy conversion efficiency of the proposed novel single-switch series resonant converter topology reaches up to 95.1%. The experimental results reveal satisfactory performance.