Due to the randomness of renewable energy

high proportion of grid-connected renewable energy in the future will bring unprecedented challenges to power system operation. The insufficient flexibility resource limits the development of renewable energy. The flexible load can be used as a kind of flexible resources to participate in shifting peak load and reserve of the power system. According to the response mechanism

the flexible load can be divided into incentive-based load and price-based load. Based on the extended probabilistic sequence operation theory

this paper develops the probability models characterizing uncertainties of incentive-based load and price-based load

respectively. Then

the probability model characterizing the uncertainty of wind power is built. To response to the randomness and fluctuation of wind power

based on the theory of risk control and risk cost

this paper develops a day-ahead optimal dispatch model of power system considering the randomness of both demand response and wind power. The opportunity constraints are transformed through sequence operations

then the developed stochastic optimization problem is reduced to a deterministic optimization problem with linear constraints for solving. Finally

the model is verified by a numerical example

and the practical value of sequence operation applied in uncertainty problem is analyzed.