Congestion Dispatching Model Considering Real-Time Operational Risks With Large-scale Wind Power Integration

As the most used new energy resource,wind power has become an important measure for China to promote energy production,consumption revolution and energy transformation.But the uncertainty and limited schedulability of large-scale wind power integration will lead to the increase of transmission congestion probability.Part of transmission lines will reach the stability limits when adopting deterministic method for congestion management,furthermore,forecasting error of wind power will result in system’s congestion again in real-time operation.In order to eliminate transmission congestion and make the system able to withstand the case of congestion again,taking the uncertainty of wind power into account to optimize resource alocation has practical significance;furthermore,with the rapid development of active distribution network(ADN)technology.It is worth further studying on how to take ADN into transmission congestion management and then conducting congestion dispatching from both generation and demand side.Aiming at transmission congestion management with large-scale wind power integration in the competitive electricity market,the following research is carried out in this paper.Based on the probability distribution of prediction error of wind power output,wind power scenarios are obtained from Monte Carlo and heuristic synchronous calback algorithm.And then we can proceed real-time simulation based on these wind power scenarios combined with generators’ real-time adjustment strategy,so that the evaluation indicators about system congestion again can be established.These indexes are able to describe the probability of system congestion again with large-scale uncertain wind power integration,and it has guiding significance for implementation and improvement for congestion dispatching scheme.Real-time operational risk indexes about wind curtailment and load shedding are established with regard to wind power uncertainty.In order to eliminate transmission congestion and make the system able to withstand the case of congestion again,this paper proposes a novel congestion dispatch model in which the forecasting error of wind power is expressed as random variable,and chance constrained programming is introduced to simulate real-time operational uncertainties.IEEE RTS-24 bus system ilustrates that this model are able to cope with wind power uncertainty and decrease the probability of congestion again in real-time operation.Based on the feasibility analysis of ADN participating in transmission congestion management,and the above model witch adopting chance constrained programming,this paper introduces the flexible resources in ADN for active management,thus,a bi-level model about transmission congestion management with ADN participating in and considering real-time operational risks is established.The upper level model whose objective minimizes the total costs of system congestion dispatching is similar to the previous model we have built,and the level model describes each ADN’s own operation optimization problem.Case study shows that flexible resources in ADN are utilized based on the bi-level model,and it can decrease the probability of congestion again further more as well as improving the economy of the system.