Sensitivity Analysis of a Current-Source Inverter-Based Three-phase Grid-connected Photovoltaic System

In this paper, first, a novel accurate small-signal model of a three-phase current source inverter (CSI)-based grid-connected photovoltaic (PV) system is derived. The model takes into account the nonlinear characteristics of PV arrays, as well as the controller and grid-side dynamics. Then, the developed small-signal model is employed to investigate the impact of different parameters on the stability of the CSI-based PV system, through sensitivity analysis. The sensitivity to variations of different parameters is assessed by tracking the positions of real parts of the eigenvalues corresponding to the dominant state variables in the s-plane. Insolation level, controller gains, and grid inductance are the parameters considered to study the sensitivity of state variables.