Design and Analysis of Microinverter Based Solar Grid Tied Photovoltaic System

Er. Sandesh Kunwar, Dr. Prof. Laxman Poudel

This study intends to design and perform financial analysis of the solar photovoltaic (PV) microinverter for grid connected system. A micro-inverter is the portable inverter used in photovoltaics, that inverts direct current (DC) produced by a solar module to alternating current (AC). Microinverter with low frequency transformer configuration design is considered for the research. For grid connected system, microinverter needs to synchronize voltage and frequency while injecting active power to the grid, so Phase Locked Loop (PLL) has been used in microinverter control algorithm. The coordinated design of LCL filter circuit and current control algorithm is used to limit the harmonic of the system within the 5 percent and regulated the output voltage and frequency within the grid limit. About 12 PV module with capacity of 2.8 kW microinverter system and equivalent string inverter PV system is simulated in MATLAB. In the computer-based simulation, when 2 or more PV modules are shaded in the string configuration, there is drastically decrease of DC voltage causing system  to collapse unlike microinverter system where the performance of shaded microinverter doesn’t impact the output voltage of others.

https://dx.doi.org/10.31873/IJEAS/6.4.2019.27