Study on the optimal proportion of wind and solar capacity in transmission constraint area based on Copula theory

Due to the outputs of wind power and solar power have natural complementarity in time and space, and the combined power of wind and solar can reduce the random, intermittent and volatility of the output, so the establishment of their joint distribution function can improve the level of evaluation of the combined power of wind and solar. Therefore, based on the sequential output data of wind/solar power in jibei grid, this article gets the cumulative distribution function of wind/solar power by kernel density estimation, and structures the two binary joint distribution function by Copula connect function. In view of the new energy accessing area which is constrained by transmission channel, based on the above joint distribution function, this article rational deploys the capacity of wind power and solar power in order to coordinate improve the curtailment of new energy power and the utilization of transmission channel. The example analysis confirmed that the method of calculating optimal proportion of wind and solar capacity is simple and feasible, which can be practically used in the situation of the new energy power curtailment of our country.