The main objective of this thesis is to compare and analyze two different high-gain dc-dc power electronic converters based on coupled inductors and capacitor-diode multiplier cells. The idea of these converters is to integrate the solar energy with a 400V DC microgrid. DC microgrids are more efficient, less expensive, and more reliable compared to AC microgrids. They also favor the integration of renewable energy sources. With the growing need for the utilization of more renewable sources of energy, photovoltaic panels have become one of the trending technologies which convert the energy from the sun to a useable electrical power. But these panels produce a low dc output voltage which cannot directly be connected to the high voltage dc distribution of the grid. They require high-gain dc-dc converters suitable for converting the output voltage of the solar panels to the dc distribution grid voltage. The topologies studied in this thesis provide a high dc voltage gain suitable for this application. The other significant advantage of these topologies is a continuous input current which increases the effective utilization of the source. These converters can also be used in applications involving high gain dc-dc conversion such as fuel cells, and energy storage applications like ultracapacitors. In this thesis, the different operating modes of the two high-gain dc-dc converters are explained in detail. Also, the voltage and current stresses seen by the components have been derived and power loss analysis is carried out for both the topologies. Recently, GaN switches have gained popularity for their higher efficiencies at higher switching frequencies, so this thesis also makes an attempt to compare Si to GaN devices in terms of efficiency improvements for the studied converters --Abstract, page iii