High Step-Up DC-DC Converter Based on Multi-Cell Coupled Inductor Diode-Capacitor Network

Due to renewable energy sources output voltage is low and fluctuating,front boost DC-DC converter is indispensable in grid-tied system.High voltage conversion ratio can be realized through diode-capacitor network and cascade structure while inrush current is severe because of the directly charging through diode between the adjacent boost cells.In this article,a novel high step-up DC-DC converter based on multi-cell coupled inductor diode-capacitor network is proposed which conquers the inrush current problem and enhances the voltage boost capability remarkably.The proposed topology has the following advantages: 1)Increase the voltage gain and decrease the voltage stress of semiconductors. 2)realize the naturally switching off of all the diodes in the circuit and improve the efficiency. 3)The voltage stress of semiconductors is not related to voltage gain when cell number is even. 4)reduce turns ratio and volume of coupled inductor. 5)single switch working mode ease the control complexity and decrease the drive circuit cost.The simulation results and experiment outcome testify the validity of theoretical analysis.