Energy Management for Large-Scale Grid Connected PV - Batteries System

The intermittency of solar energy is high, since it depends on both the availability of sun and real-time weather conditions. This situation is a challenge for stabilizing the production of large-scale grid connected PV system. Energy storage system (ESS) is used as a solution to control the effect of solar intermittency and as an energy buffer to a grid-connected PV plant. ESS control the energy flow and provide smooth generation to balance between the demand and generation. This paper investigates an energy management approach with energy storage system (ESS) for large-scale grid connected photovoltaic (PV) system to stabilize the produced power. The model consists of a 1 MW PV system and 1 MW lithium-ion batteries connected to the grid by DC-DC converters and DC-AC inverters. The storage batteries along with controller and bidirectional converters are to charge and discharge based on the grid demand. PV-batteries system is simulated by MATLAB-SIMULINK under different circumstances of various irradiance levels. The output results for each condition are plotted and analyzed with respect to power of PV, grid and batteries.