Isolated high step-up switched-boost DC/DC converter with modified control method

摘要

In this study, a new isolated high-gain switched-boost DC/DC converter employing two symmetrical switched-boost networks along with a modified control algorithm based on the combination of the pulse-width modulation (PWM) and phase-shift modulation is proposed. Utilising symmetrical switched-boost networks increase the voltage gain of the proposed converter, significantly. Moreover, applying the proposed switching algorithm on the proposed isolated switched-boost DC/DC converter leads to the following advantages: (i) high-voltage gain, (ii) zero voltage switching (ZVS) turn-on of two switches, (iii) ZVS turn-off of two switches and (iv) appearing three controllable parameters (the shoot-through duty cycle, the phase shift and the transformer turns ratio) in all of the equations including the voltage gain equation, which enhances the flexibility of the converter. In this study, the steady-state analysis, design procedure of the elements, and voltage and current stress of the semiconductors are given. Then, the proposed converter and the proposed switching algorithm are compared with similar converters and modulation techniques in order to highlight their features and drawbacks. Finally, experimental results are obtained to substantiate the theoretical analysis accuracy.