Simulation of a wind diesel system with a Ni-Cd battery energy storage

The subject of this paper is to present the modeling of a Wind Diesel Hybrid System (WDHS) composed by a Diesel Generator (DG), a Wind Turbine Generator (WTG), the consumer Load, a Ni-Cd Battery based Energy Storage System (BESS), a Dump Load and a Distributed Control System (DCS). All the models of the previously mentioned components are presented and the performance of the WDHS has been tested through simulation. Simulation results with graphs for the frequency, voltage and active powers for the elements of the Isolated Power System are presented for negative load and wind speed steps. The negative load step leads the system to a DG power inversion where the DG speed governor cannot control system frequency and it is shown how the DCS orders the BESS to load artificially the system until the DG power falls in a positive power interval. The negative wind step decreases the WTG produced power, returning the power system to a situation where the needed DG power returns to positive, so that the BESS is not needed to load the system.