The improvement of cascaded converter design using quadratic boosting structure with high voltage gain and low duty cycle

Two novel designs of DC-DC boost converters, one using cascaded structure and one with low duty cycle are presented in this paper. Each of them consists two boosting cells with only one switch to control the on-off state of the circuit. The main advantage of these two designs is providing high step-up output ratio. This is significantly useful for renewable energy system with low output voltage, such as solar energy systems, to boost its output voltage to higher ones for grid-connected equipment. One design works under low duty cycle (less than 36%). The operational modes are designed in continuous-current mode (CCM) and this can simplify the analysis and understanding of the converter circuit. In this paper, the theoretical analysis and simulation results will verify the potential value of two designs and the designed parameters will be listed for further research.