Energy storage variation ratio and power efficiency of Cuk converter in continuous mode

The amount of storage energy in comparison to the output energy for basic topologies deserves deep research which was proposed over ten years ago. It has been analyzed and demonstrated that the larger is the energy variation ratio of power devices including inductors and capacitors, the larger is power loss, thus lower efficiency. This paper extends this theory to Cuk converter and derived the energy storage variation ratio and its relationship with power loss. Simulation in conducted in PSIM platform and verified the energy ratio´s impact on efficiency via detailed calculation. Finally a sample Cuk converter is built, and experiment results further demonstrated the energy ratio´s relationship with power loss and efficiency from one perspective, which could help us understand and design a converter better.