Analysis and simulation of a multiple input interleaved boost converter for renewable energy applications

With the increasing penetration of wind, solar and other renewable energy sources the demand for modular, reliable power electronic devices are necessary to accommodate the intermittent nature of these sources. Many low voltage communication systems supplied by batteries, super capacitors, and fuel cells utilizes a dc-dc boost converter. For high power applications the boost converter is not as efficient because of the high input current ripple that is added to the current flowing out of a fuel cell and the input current spans over a wide range contributing to a reduction in battery life. With the variety of photovoltaic products available commercially, each device has its own electrical characteristics and the challenge therefore is providing for an aggregate amount of devices for hybrid applications or grid integration. A multiple input converter provides improved operation because it accounts for mismatch in photovoltaic devices and provides for independent and simultaneous power flow from these sources. The interleaved boost converter provides for higher efficiency, reduced input and output ripple while maintaining high power density, thereby making it well suited for high power applications. The interleaved dc-dc boost converter consists of two parallel connected boost converters and employs an interleaving method that provides for an 180^o phase shifted switching scheme. The multiple input interleaved boost converter (MIIBC) is analyzed using the synthesis approach and is constituted by a cascade of two interleaved boost converters sharing a common output stage. The dc inputs to the multiple input interleaved boost converter is a 45V/6.5kW fuel cell device and a 50V photovoltaic module, which are modelled using the MATLAB/Simulink package. Simulation results confirm the improvements of using this new converter for renewable energy applications.