Source-grid Coordination Multi-objective Optimal Scheduling Considering The Confidence Risk Of Wind Power

In recent years,the installed capacity of wind power has grown rapidly,and the scale of wind power grid connection has continued to increase.However,the wind power output is uncertain due to the uncontrollable nature wind speed.Compared with conventional energy sources,wind power output is more intermittent and random.However,the traditional optimal scheduling model is mostly based on the certainty principle.The uncertainty brought by large-scale wind power grid connection will bring new challenges to the scheduling and operation of the power system.In order to effectively ensure that the system can operate safely and economically while making full use of wind energy,which it is necessary to establish a more strict power system optimization scheduling model.Thence,this paper discuss wind power grid-connected risk,then research the power system multi-objective optimal scheduling model and algorithm for wind power connection.The main frame of the paper have summarized as follows.1)A risk-confidence risk model is constructed.In order to more reasonably and flexibly evaluate the risk of wind power to the optimal scheduling of the power system and reduce the conservativeness of decisions,a quantitative calculation method for wind power over/under-estimation confidence risk is proposed based on the constrained probability of wind power.In the meantime,an approximate calculation method of the shortest confidence interval is proposed,which solve the problem that the weibull distribution is not accurate enough to estimate the interval.2)A multi-objective optimal power flow model for the power system that takes into account the risk cost of wind power is constructed.The confidence risk cost considered for wind power access that will cause the system to maintain stable operation is introduced into economic targets,which will bring the system's operating costs and polluted gases.Emissions are optimization goals,and constraints such as node power balance,unit power output,and branch transmission power are integrated.Aiming at solving the model,a new multi-objective compound backtracking search(MOCBS)algorithm is designed.Different mutation strategies are embedded in the backtracking algorithm to balance the speed and depth of optimization of the algorithm to a certain extent.The simulation study of the calculation example shows that the confidence risk cost calculation method can be more flexible,reasonable and accurate to quantify the risk of wind power grid connection;the MOCBS algorithm can obtain a wider,uniform and accurate Pareto front.3)A source-grid coordination optimization scheduling model that takes into account the wind power confidence risk is constructed,and the risk of wind power grid connection is characterized as the comprehensive deviation of wind power confidence risk power,and the environmental costs of conventional units are considered in the economic objective.The system's operating cost and risk power comprehensive deviation are taken as optimization objectives,and transformer tap adjustment and reactive power compensation capacity are introduced into the decision variables for more widely source-grid coordination optimization.A feasibility and non-dominated comprehensive sorting(FNSBS)algorithm is proposed.Compared with the penalty function method,the feasibility sorting method can eliminate the subjectivity in which penalty factors need to be preset.The case study of the calculation example shows that the risk power comprehensive deviation calculation method can reduce the conservativeness of the decision-making that takes into account wind power grid connection to a certain extent;the source-grid coordinated optimization scheduling model can obtain an operating scheme with lower system operating costs and lower risk power comprehensive deviation;The FNSBS algorithm can search for high-quality solutions under complex problems.