Analysis of DCM interleaved boost converter for PV AC-module application

An interleaved boost converter (IBC) has the advantage of the reduced current ripple, and hence minimizing the input filter size. However, conventional IBC was not used in high voltage-gain applications to avoid the extreme duty cycle. In this paper, the performance of the IBC is analysed when employed, in the discontinuous conduction mode (DCM), in a dual-stage photovoltaic (PV) AC-module system. Conventional boost converters models with 2-phase IBC and 3-phase IBC are developed and simulated using the MATLAB/SIMULINK tool in a dual-stage, grid-connected PV AC-module system. The converters were simulated under DCM, and the duty cycle, current ripple, and efficiency were analysed under different solar irradiance levels. To identify the most efficient design/ mode of operation, DCM is considered for the phase currents of the IBC while both the continuous conduction mode (CCM) and the DCM are investigated for the entire input current. The results showed that operating the IBC at DCMof the phase currents whilst keeping the total input current at CCM reduces the input current ripple and improves the efficiency and reliability of the converter.