Solar PV Fed DC Microgrid: Applications, Converter Selection, Design and Testing

In this research article, major applications which use solar PV fed DC microgrid for either their routine operation or gain additional advantages over existing electrical power architecture are elaborated. The role of power converters in interfacing the input with the required output is highlighted. The advantages of solar PV fed DC microgrid are demonstrated by designing and testing a non-isolated high gain high power (HGHP) DC-DC converter to meet the DC distribution voltage level. The proposed converter is synthesized by using hybrid combination of three-phase interleaved boost converter (IBC) with voltage lift technique along with coupled inductors (CIs) and voltage multiplier cell (VMC). The proposed concept is practically demonstrated and the adopted design techniques are validated using simulation and experimentation. The proposed converter with 60V/1.1kV, 100kHz and 3kW rating operates at 92.3% full-load efficiency under practical conditions. Due to the gain extension techniques adopted, the switches used in the proposed converter are subjected to a voltage stress which is only 36% of the output voltage. Due to interleaving technique, the input current ripple and the current stress on the switches are only 15% and 33% of the input current respectively. Key performance parameters of this converter are thoroughly investigated and benchmarked with some state-of-the art converters to appreciate the salient features of the presented converter. The ability to yield higher voltage gain at safe duty ratio, high power handling capacity, low voltage and current stresses on the power switches are the main advantages of the proposed converter.