Estimating the dynamic power requirements for controllable energy storage on PV microgrid

This paper investigates the dynamic power requirements for controllable energy storage systems used for stabilization of standalone three-phase low-voltage microgrids with high penetration of PV energy. It uses recorded data of fluctuating Photo-voltaic (PV) sources and fluctuating loads to determine how an ideal controllable energy storage can be used to stabilize a microgrid with 100% PV energy penetration. Using the data recorded for a typical bad day in Johannesburg, the sampling time required to capture the dynamics in PV sources was found to be 2 seconds. However this report uses sampling time of 1 second to calculate the ramp rate required for the energy storage to stabilize a PV microgrid. For the case considered in this paper, the ramp rate was found to be 0.4 pu/second.