Abstract:

Instability of photovoltaic power generation is one of main factors affecting its applications. Integration of an energy storage system (ESS) into grid-connected photovoltaic power stations not only effectively smooths the power output, but also improves power demand management, leading to the use of more renewable energy. Taking a 1MW solar PV plant as an example, the smoothing strategy was studied on the basis of the PV plant output and the time-sharing-control scheduling strategy was established by using the output power and the state of charge (SOC) of the ESS. Meanwhile, the operating characteristics of the ESS with different connection modes to photovoltaic power stations and the effect of the ESS on the load characteristics of the PV connected power grid were investigated, and an optimized solution for ESS design was proposed.

Key words: photovoltaic, energy storage, grid-connection mode