Sliding mode controller-based switched-capacitor-based high DC gain and low voltage stress DC-DC boost converter for photovoltaic applications

Abstract

High-gain DC-DC power boost converters blocks have been converted to the main transitional topologies for the PV applications to enhance the level of the generated voltages of these panels for grid applications. The single switched and transformer-less converters due to their higher efficiency, and cheaper and light-weighted features are the first selection for these converters design. This study presents a transformer-less DC-DC power boost converter with a switched-capacitor structure with a sliding mode controller (SMC) to increase the DC voltage gain and decrease the voltage stress on the power switch. This advantage is doing based on the preamplifier block by using an extra inductor at the input side. Also, the switched-capacitor block easily decreases the voltage stresses on the main power switch and other diodes. Presenting high voltages under the small duty cycles is one of the most important features of the proposed converter that allows longer off-time duration for power switch for Continuous Current Mode (CCM) operations. This leads to lower amounts of the dynamic losses for the power switch and higher efficiency. On the other hand, the control process of the proposed converter under the different input voltages and output powers and loads due to using only one power switch is simpler compared with multi switched topologies. All calculations for obtaining the gain, currents follow through the components, voltage ripples through the capacitors, and efficiency is presented. The hardware prototype with 300 W power is tested and the results confirm the theoretical calculations.