Modeling of Small Island Power Systems with Integrated PV and Battery Energy Storage using EMTP-RV

Deployment of solar photovoltaic (PV) generation is a key step toward achieving energy sustainability, especially in Small Island Developing States. However, the nature of distributed solar PV is different to conventional generation and can adversely affect load flows, as well as the voltage and frequency stability of the grid. In this paper, the Tobago power system was modelled along with solar PV generation and Battery Energy Storage System (BESS) to determine the steady state and dynamic impacts, by performing simulations in Electromagnetic Transients Program, EMTP RV 4.1. Steady state simulations were conducted using various solar PV connection points and load growths, while transient analysis was completed by increasing solar PV penetration levels and testing the system response to different fault locations. An existing load bus was the most suitable location for integrating solar PV since the step-down transformers were currently at risk of overloading. Using this configuration, it was found that the Tobago power system maintained stability up to 30% PV penetration, however the frequency response was affected due to reduction in grid inertia caused by the displacement of synchronous generator machines. The BESS mitigated this effect by providing virtual inertia and frequency regulation.