LnC2n-2 Network-Based High-Gain Modular DC–DC Converter for PV Applications With MPPT

Abstract

To optimize the photovoltaic (PV) sources, a power electronic interface becomes indispensable to boost the output voltage using the maximum power point tracking (MPPT) algorithm. However, existing converters suffer from either low voltage gain or a higher component count. Therefore, this article proposes a MPPT-enabled L_nC_2n-2 network-based high-gain modular dc–dc converter capable of achieving high gain and maximum power from PV by utilizing fewer components. In the proposed L_nC_2n-2 network, ncorresponds to a number of stages, and each stage of the network comprises two capacitors, one diode, and one inductor. The proposed converter is expandable by increasing the number of stages and provides higher gain at a lower duty ratio with increasing n. Basic L₃C₄ modular topology for n= 3 is formulated and is analyzed in both continuous conducting mode (CCM) and discontinuous conducting mode (DCM). Further, an incremental conductance algorithm is applied for MPPT operations to verify the integrability of the converter with PV. The converter is also evaluated against different existing converter topologies concerning voltage gain, switches, and overall component count. A 300-watt experimental prototype is developed for n= 3 to verify the proposed converter in CCM, DCM, and MPPT operation with the help of a PV emulator and TI F28335 microcontroller. The proposed topology for n= 4 has also been validated in CCM to demonstrate the converter's modularity.