Supersession of large penetration photovoltaic power transients using storage batteries

This paper treats the impact of output fluctuations caused by cloud transients on the distribution power systems fed by large photovoltaic (PV) system by considering PHEVs to be main component of future smart grids. The PHEVs charging station is seen as bulk storage battery which acts as controllable loads and interacts with intermittent PV power generation. A control strategy for the PHEVs battery is developed in which the PV generation scheduled power is prepared based on clear sky assumption. In normal state, the storage batteries are set in charging mode. The results simulate the impact of 50% PV penetration on a 33-node radial distribution feeder during 24 hour period. PV generation plants were connected at buses 18 and 33 which display weakest voltages. The simulations are carried out for clear sky, full cloudy sky and cloud transient with different models of the PV interface inverter. The results show that the generating reactive power by PV inverter enhances the feeder voltage profiles. However, during cloud transient, application of PHEVs storage systems is required to alleviate the feeder voltage flicker. PHEVs charging stations were connected at the same buses of PV generation plants. The developed controllers can be integrated with charging station smart meter and can be extended for real time billing schemes in both charging and discharging modes.