Single-switch ultra-high step-Up DC-DC converter for PV applications
T. Sakthi Ram, L. Yogesh, Rahul Srikanth, M. Prabhakar, S. Angalaeswari
Abstract
In this research article, a high-gain DC-DC converter that is suitable for photovoltaic (PV) applications and possesses ultra-high step-up voltage gain capability is presented. Despite using a single switch, the proposed converter yields a voltage gain value that is more than double the cubic times the output voltage obtained from a classical boost converter (CBC). In the proposed converter, two gain extension techniques viz., switched inductor (SI) networks and enhanced quadratic boost converter (EQBC) structure with classical voltage multiplier cells (VMC) are synergized to obtain a nominal voltage gain of 20. The proposed synthesis methodology is practically validated by conducting experiments on a 20 V to 400 V, 100 W prototype converter. The single switch prototype converter operates at a full-load efficiency of 94.3 % when switched at 50 kHz frequency and 0.475 duty ratio. Under dynamic conditions, when the input voltage is reduced to 16 V, the voltage gain of the proposed converter is extended safely to 25 to meet the 400 V load requirement. The salient features of the proposed converter are clearly proven by comparing it with several converters with quadratic, cubic, and quartic voltage gain functions. Waveforms depicting the operating soft-start process and setting up of closed-loop operation Radial chart portraying the key attributes used to benchmark the SSUHSDC with the converters compared in Table III