Power system small-signal oscillation stability as affected by large-scale PV penetration

This paper investigates the impact of a large photovoltaic (PV) penetration on power system small signal oscillation stability. A comprehensive model of a single-machine infinite-bus power system integrated with a PV power generation power plant is established. Numerical computation of damping torque contribution from the PV power plant is carried out, which is confirmed by the results of calculation of system oscillation model and non-linear simulation. Those results indicate that power system oscillation stability can be affected either positively or negatively. There exists an operational limit of the PV power plant as far as system oscillation stability is concerned. Beyond the operational limit, the PV generation supplies negative damping torque, thus damaging system oscillation stability. Hence for the safe penetration of PV generation into power systems, the operational limit of oscillation stability of the PV power plant must be considered.