Current Controller Modeling for an Interleaved Boost with Voltage Multiplier Cells for PV Applications

Nowadays, due to the increasing interest on low voltage renewable energy sources, like those based on photovoltaic modules and fuel-cells, an intensive academic and industrial research has been focusing on high step-up ratio DC-DC converters. One simple way to implement a high gain converter is to combine a boost topology at the input stage with a number of voltage multiplier cells, in order to step-up the output voltage beyond the conventional boost capability. Since in low-voltage (renewable energy) applications the input current is typically high, interleaved topologies are employed to reduce the device stress and the current ripple by separating power into multiple phases. Current sharing in paralleled converters can be ensured by adopting current-mode control techniques. The aim of this paper is to design a current controller deriving the duty-to-input current small signal model for the interleaved boost with one voltage multiplier cell, comparing it with the conventional interleaved boost. This result is further used to estimate the current function when the number of cells increases. The derived model has been validated by PLECS simulations and by experimental measurements based on a 500 W-interleaved boost prototype with two voltage multiplier cells, digitally controlled by DSP TMS320F28377.status: publishe