Author(s)

Chen Wang, Suling Chen

Corresponding Author

Chen Wang

Abstract

The intermittence and fluctuation of wind energy have brought adverse effects to large-scale grid-connection of wind power. Installing energy storage system at the outlet of wind farm can effectively adjust the rate of change of grid-connection power and improve the stability of grid-connection operation of wind farm. This paper takes energy storage grid-connected inverter and its optimal control as the research object. Starting from considering the smoothness of grid-connected power and prolonging the service life of energy storage system, an optimal control method based on variable smoothing time constant and power limiting is proposed. The protection of battery energy storage system is realized by adjusting the smoothing time constant and power limiting in real time. Taking one day as the time scale and energy storage system electricity balance as the criterion, the problem of excessive peak valley difference in distribution network is effectively improved. At the same time, the uncertain change of battery capacity caused by other control functions of energy storage system caused by power grid disturbance is solved by online correction. The experimental results verify the effectiveness and feasibility of the proposed optimal control method, which can avoid the overcharge, overdischarge and overload of the battery energy storage system.

Keywords

Wind farm; Smoothing time constant; Battery energy storage system; Cutting Peak and Filling Valley