Weak Grid Operation of A Grid-Following Current-Sourced PV Solar System

Abstract

A barrier to achieving high switching frequencies for the popular voltage-sourced inverter (VSI) topology is that the output voltage of a VSI is subject to significant changes instantaneously. The current-soured inverters (CSI) avoid such shortcoming and have been applied in grid-following inverters for photovoltaic (PV) solar. This paper presents the dynamic performance of a CSI grid-following PV solar operating with a weak grid. The simulation is carried out in MATLAB/Simulink with SimPowerSystems toolbox. The case study results illustrate the operation limits of a grid-following CSI and how those limits are associated with voltage stability and CSI's control settings.