Integrating battery banks to wind farms for frequency support provision-capacity sizing and support algorithms

The expected high penetration levels of wind energy in power systems require robust and practical solutions to maintain typical conventional systems performance. Wind farms (WFs) positive contribution in eliminating grid frequency deviations is still a grey area, especially when they replace considerable conventional generation capacities. This paper offers a sizing algorithm to integrate storage battery banks (SBs) in WFs to provide feasible power support during frequency events. This algorithm determines the required rated power and capacity of each SB inside a WF according to several constrains, including wind speed (WS) characteristics at WF location. The size of the SB is based on a statistical study for the amounts of rejected wind power, and the events of low wind production. The offered operation algorithm controls the SB charging, discharging, and standby modes based on the acquisition of different dynamic variables, for example, WF output, load demand, and storage cells' state of charge. The operation algorithm aims to mitigate frequency drops and rejected wind power and to maintain the battery lifetime. Both algorithms are applied on a defined sector from a genuine conventional system merged with real WS chronological records at certain locations which are candidates to host WFs. Results reveal the positive influence of SB involvement on frequency excursions clearance; in addition, wasted wind energy is mitigated since wind turbines de-loading techniques are avoided and some rejected wind power is utilized to charge the installed SBs. Precise models are integrated through MATLAB and Simulink simulation environment. (C) 2015 AIP Publishing LLC.