| At present,the construction of renewable energy projects becomes an effective measure to adjust the energy structure and achieve green development in China.However,on account of the randomness and volatility of renewable energy sources(RES),the accuracy of its forecast power can only be satisfactory when the prediction is carried out a few minutes and hours before power generation.So the deviation between the day-ahead predicted output of RES and the intra-day actual output affects the implementation of its power generation plan.In addition to the limitation of imperfect market mechanism and the underdeveloped structure of power grid,the ability of electricity grid to consume tremendous renewable energy does not match the demand for the integration of wholesale green power.As a result of the problems mentioned above,the inevitable congestion will affect the safety and stability of system and even lead to wind and solar power curtailment,which do harm to the process of the further consumption of RES.Therefore,in order to take the security of the system,the consumption rate of RES and the economy of congestion dispatching into account,it is necessary to promote the renewable energy consumption through the intra-day market carried out when the forecast is comparatively accurate.At present,the domestic spot market and congestion management mode are not mature.It mainly takes policy measures to ensure the priority of the dispatching of RES and the unilateral competition market of the generation side usually ignores the regulatory role of users.On the contrary,the foreign countries not only establish relatively complete market-oriented congestion management modes,but also effectively absorb renewable energy through bilateral competition market and corresponding balance mechanism.However,they seldom consider promoting renewable energy consumption while solving the congestion problems and emphasizing the role of the participation of source-side and load-side resources in congestion scheduling.Therefore,based on the positive attribute of directional adjustment of the generation side and load side,this paper goes deep into the study on the optimal congestion scheduling with the key point of improving the economy of congestion dispatching and the utilization rate of RES.Firstly,the study of the congestion management methods of foreign power markets will be found,which has laid the groundwork for the subsequent establishment of intra-day market dispatching framework and optimal model.Secondly,the scheduling cost of generation-side and load-side resources with the role of directional adjustment have been calculated and the content of the model has been enriched.Thirdly,for the sake of solving the congestion problems caused by prediction deviation in time,a framework of intra-day congestion optimal dispatching is established.What’s more,this paper transforms the cost of promoting the accommodation of new energy into the cost of wind and solar power curtailment and combines it with the cost of congestion scheduling together at the same time.Then the combination is treated as the objective function of the model of intra-day market for promoting the consumption of RES.Finally,the IEEE14 bus system is taken as an example to verify the model.In order to dig up the influences of the methods that the different resources participate in the market on the congestion dispatching,three different ways are set in this case.One is the way of considering the bidirectional adjustment of the generation side,one is the bidirectional adjustment of the generation side and the reduction of the load side,the other is the bidirectional adjustments of both two sides.Based on these three ways,the results of congestion scheduling cost,the consumption of RES and the situation of congestion lines are evaluated specifically,which testifies the availability of the model for solving congestion problems,reducing congestion scheduling cost and improving the utilization level of the RES. |
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