Small-signal stability and transient analysis of an autonomous PV system

This paper proposes an approach based on both eigenvalue and eigenvalue sensitivity to determine small-signal stability of a photovoltaic (PV) system supplying an isolated load. A DC-to-DC boost converter is employed to step up the output variable DC voltage of the PV array to a higher fixed voltage level in order to supply a required voltage for a DC-to-AC single-phase inverter feeding an isolated load. The dynamic equations of the studied PV array, the DC-to-DC boost converter, and the DC-to-AC inverter are derived in detail to examine the dynamic behavior of the studied PV system under different loading conditions. Both system eigenvalues and eigenvalue sensitivities are employed for investigate stability margin of the studied isolated PV system under small perturbations. The transient responses of the studied autonomous PV system subject to a sudden disturbance are also examined. It can be concluded from the simulation results that the proposed schemes are effective to explore the small-signal stability and transient behaviors of the studied autonomous PV system feeding an isolated load under various disturbance conditions.