Rigorous model for evaluating wind power capacity credit

Abstract

How much capacity credit should be given to wind power in generation system adequacy analysis is a question of great interest around the world. Both a theoretical analysis and an accurate evaluation on the wind power capacity credit are essential for understanding its contribution to power system reliability. Current evaluation techniques usually rely on numerical calculation procedures that do not provide an analytical analysis, or are based on assumptions that are valid only for small wind penetration. This study presents a rigorous model based on the definition of the reliability function. The derivation of the model is presented and a fast and accurate method for calculating the capacity credit is developed based on this model. The proposed method does not require strong hypotheses and is thus widely applicable, especially when current evaluation techniques might cause large errors, for example, when the wind power penetration is large and the wind power and load profile are not statistically independent. The model is used to explain how the statistical characteristics of the load and wind power affect the capacity credit, from both a statistical and chronological perspective. Numerical tests demonstrate the correctness of the proposed model and its potential applicability under different circumstances. © The Institution of Engineering and Technology 2013.