Evaluation of wind power capacity value including effects of transmission system

In recent years, investigations of the effects of the intermittency and uncertainty of wind power on power system reliability have gathered significant momentum. This paper proposes a method to model large wind farms and determine their capacity values in a manner that considers both the mechanical failures of wind turbines and the effects of the transmission system. The proposed method combines the probabilistic model of wind power and mechanical failures of wind turbines by sorting wind speeds into bands. While most methods estimate the capacity value based on generation adequacy, the method presented here also captures the effects of transmission constraints by using a composite system reliability analysis approach. Wind power capacity values were evaluated and compared for different scenarios taking into account the effects of operation and transmission line constraints and mechanical failures of wind turbines. Capacity values of wind power in composite system were compared with those of using adequacy assessment. The proposed method was applied on the IEEE-RTS to calculate the reliability indices and capacity values of wind power. The obtained results demonstrated that system operation and transmission line constrains have significant impacts on capacity values of wind farms. Also, the results showed that ignoring mechanical failures of wind turbines produces conservative assessment of the reliability indices and capacity values.