Adaptive control scheme based on transient stability mechanism for photovoltaic plants

Abstract

The world-wide application of photovoltaic (PV) plants is a promising solution to the energy crisis. However, PV plantsusually suffer from transient instability due to weakness in dynamical adaptability. This study, based on the transient stabilitymechanism, devises an adaptive control scheme to achieve transient stability enhancement for PV plants. The transient stabilitymechanism shows that the active droop factor is negatively associated with the transient stability whereas the reactive droopfactor is positively associated. The transient stability enhancement is implemented by increasing the reactive droop factor andreducing the active droop factor to raise the power angle curve. The proposed control scheme adjusts the droop factorsdynamically during the transient events by detecting the real-time electrical quantities. The control scheme advances in adesigned activation module which is able to judge if there exist transient events. A series of simulation cases demonstrate theeffectiveness of the control scheme in different transient events. Simulation results show that the control scheme adjusts droopfactors adaptively and possesses better transient stability than the normal droop control.