A New Flexibility Index in Real Time Operation Incorporating Wind Farms

Uncertainty and variability are two main specifications of wind generation and the ability of the power system to overcome these challenges is called the flexibility. Flexibility index is a measure to evaluate the flexibility level of the power system. This index should show a good view of the ability of power system and also easily converted to equivalent cost to be combined with the operation cost function. Through this approach a good trade-off between generation cost and needed flexibility can be done. In this paper, a conceptual flexibility index is introduced suitably for the real time operation in the presence of wind farms. Two main components of this index are up and down generation constraints and ramp rate limitations of each unit. So, by combination of the flexibility indices of all units, the system flexibility index is introduced which can be used as the main part of flexibility cost in the objective function. Economic dispatch simulation is used for the economic trade-off between the generation cost and the cost of flexibility to get the best level of system flexibility in the presence of wind farms considering units constraints and system loss.