Dynamic Stability Analysis of Renewable Power Systems Considering Cluster Effect of Multiple Photovoltaic Generators with Same Dynamics

Dynamic stability issues posed by large-scale photovoltaic (PV) generation can jeopardize the secure operation of renewable power systems. This paper establishes a PV solar farm equivalent model that considers the cluster effect of multiple PV generators with same dynamics. Mathematical analysis indicates that the dynamic characteristics of PV generators are central to the dynamic instability of large-scale grid-connected PV solar farms. While increasing the scale of PV generators and weakening the AC transmission line connections exacerbate dynamic instability, these factors amplify the effect but are not the root cause. A case study conducted in an actual power system with high PV generation penetration highlights that the phase-locked loop parameters of PV inverters are crucial for triggering oscillations caused by the cluster effect of multiple PV generators with same dynamics. As the number of PV generators increases and the AC transmission line connections weaken, the system’s dynamic stability deteriorates in the specific power system.