Performance Evaluation of Single-Phase Boost-Type Cascaded H-Bridge Inverter in the Applications of Grid-Tied Photovoltaic Systems
N. Hari Charan, A. Bandyopadhyay, Josep M. Guerrero
Abstract
In this paper, a new cascaded-H-bridge (CHB) inverter is proposed to enhance the input voltage of a renewable energy source to a desired level without any necessity of a dc-dc converter. The proposed topology consists of a pair of inductor and capacitor that serves as an input impedance network for the two full bridge inverters to boost the source voltage. An interleaved control scheme is proposed for the grid-tied inverter that independently supervises the duty cycle and the modulation index. The maximum power point tracking system commands the duty cycle whereas the dc-link voltage regulator maintains a constant voltage across the capacitors irrespective of the disturbances in the system. The proposed control scheme is primarily investigated in the MATLAB/SIMULINK platform. Different test cases are analysed to explore the performance of the proposed inverter in the applications of photovoltaic systems. An experimental prototype is designed in the laboratory to validate the simulation results.