The large-scale grid-connection of multiple wind farms has brought a great challenge to the economic dispatch of power grid. This paper focuses on the dynamic economic dispatch of power grid with multiple wind farms. First

the Copula theory is introduced to develop the model of joint distribution for the output power of multiple wind farms. Secondly

a stochastic optimization model of the 24 hour dynamic economic dispatch is established. In order to deal with the stochastic characteristics of wind output power

a two-stage compensation algorithm is applied and the original model is transformed into a two-stage model. The first-stage model is of constraints about conventional variables

and the expected compensation value is added to the objective function. The second-stage model is constrained by random variables

and its objective function is to minimize the expected compensation value. The optimal solution is obtained by the alternating iteration of the two models. The proposed model is finally verified by the IEEE 118-bus system and an actual provincial power grid.