Wind power is a new stochastic variable in the power system operation and dispatch

the correlation of wind power generation should be quantified to determine the variability of power flows

the system uncertainty and operational risk. This paper analyzes the tail dependency of wind power first

and then improves a hybrid Copula method to model the wind power dependency considering the dependency structure. The method constructs a hybrid Copula which can describe the tail characteristic by linear weight

then uses the expectation maximization (EM) algorithm to evaluate the parameter

the analysis results of two typical wind farms show that hybrid Copula can accurately describe the correlation structure of wind power

and the correlation index and tail correlation index can be easily calculated based on the correlation measure theory of Copula.