Loss Analysis of Conventional and Three Level Boost DC-DC Converters employed for MPPT in PV Systems

Photovoltaic (PV) systems are often exposed to nonuniform insolation due to shading. Under these conditions, there exists multiple peaks in their power-voltage (P-V) characteristics and among which there is one global maximum power point (GMPP). Several GMPP tracking methods employed in the literature have focused mainly on the tracking efficiency. But, the PV system output has to include the DC-DC converter losses also to get the actual estimate of the power extracted. Hence, this paper attempts to analyze the losses incurred in the DCDC converters namely conventional boost converter (CBC) and three-level boost converter (TLBC) connected to a PV array. It is observed that the efficiency of converters depends on the location of GMPP in the (P-V) curve. Further, the impact of switching frequency on the losses of aforementioned two topologies is discussed. A detailed comparison of the loss analysis performed with simulation results obtained from MATLAB/Simulink is provided.