Modified step-up boost converter with coupled-inductor and super-lift techniques

In this study, a modified efficient step-up boost converter is proposed. The proposed structure employs coupled-inductor and super-lift techniques to achieve high voltage gain. The super-lift stage absorbs the available energy in the leakage inductance of the coupled inductor, clamps the off-state voltage of the main switch, and reaches a moderate voltage gain. Moreover, the coupled-inductor technique offers high voltage gain, low off-state voltage for the main switch, and alleviates the reverse-recovery problem of the output diode. Hence, using these two techniques, the proposed converter achieves high step-up voltage gain and eliminates the drawbacks of the conventional boost converter. The proposed converter is analysed in details and a hardware prototype with the input voltage of 15 V, output voltage of 200 V and the nominal power of 100 W is utilised for the experimental investigation.