Investigation of FRT Capability in a Grid Connected Photovoltaic Power Plant via dc-link Breaking Chopper Approach

The increased application of solar photovoltaic (PV) is a great advantage for achieving energy reliability in the existing electric power systems. However, there are challenges in the variability of solar power generation and power quality issues during the occurrences of balanced and unbalanced grid faults in the utility. To understand and propose a solution to the cited issues, this paper presents a detailed analysis in characterizing the grid-connected solar systems. A conventional dq-based current control is performed for the operation of grid grid-connected voltage source inverter. The functionality to attribute fault ride through (FRT) is done by utilizing a dc-link braking chopper which is controlled during the incidence of grid fault. The simulation and verification of the solar PV system is done in the MATLAB environment. Case studies showcasing a detailed analysis of loading variation, and occurrence of 3-phase fault are considered for the verification of breaking chopper-based fault ride through control in the considered photovoltaic power plant. The results indicate that dc-link breaking chopper-based control offers a simplified approach to providing the ride-through capability in such systems.