Probabilistic Spinning Reserve Optimization By A Representative Contingency Constrained Unit Commitment

Due to the influence of uncertain factors existing in power source?grid or load,Reserve need to be configured reasonablely to ensure the balance between reliability and economy of system.To cope with various uncertainties,for traditional deterministic criterion of reserve configuration,it is no longer applicable to modern power system which become gradual marketization.It is a current way to establish the probabilistic reserve optimization model to seek the optimal reserve in which the probabilistic features of various uncertainties are considered.But the established probabilistic reserve optimization model is caculated intricately,especially after the renewable energy sources are considered.Therefore,it is necessary to research deeply to elabrate the model,in order to make the model calculated accurately and efficiently.Firstly,this paper summarizes the models and solutions of probabilistic reserve optimization,and point out that the effective availability of reserve configuration can't be considered in the current simplified methods to probabilistic reserve optimization models with reliability criteria constraint,which leads to the established models can't be implemented well.Summarize the reserve configuration methods which considers the unit outage and wind power uncertainty together,then point out that reserve configuring and unit commitmenting simultaneously,namely,to establish stochastic UC model conforms to the requirements of the market environment;Analyze deeply the characteristic of stochastic model and explore that covering phenomenon exists in the model,and the covering effect can be used to simplify the model and make it easy to cacaulate.Secondly,based on LOLP constrained reserve optimization model,research the way of reserve configuration in RCUC model and LCUC model through the curve analysis between LOLP and SSR,and found there are two tradeoffs exsiting in LCUC model.In RCUC model,there is the primary tradeoff between economy and reliability as reserve increases.In addition,for fixed reserve,there is another tradeoff between economy and reliability in the process of power and reserve distribution to the units.And some methods transform LCUC to RCUC to calculate,which actual ignores the second tradeoff,resulting in the effectiveness of the reserve configuration deteriorated,and leading to more serious suboptimal solution.Again,in this paper,LOLP constraints can be converted to a series of linear constraints,which correspond to unit outage contengencies that don't cause loss of load.On account of the covering effect among contengencies,a series of linear constraints can be covered with a few representative constraints,so that LCUC model can be converted to representative contengencies constrained UC(RCCUC)model.Then,constraints addition method and improved constraints addition method are proposed to solve the RCCUC model.They both add the constraints and optimize in a iteration way,and the difference is the method to search the representative contengencies.Respectively,the method and the improved method to search the representative contengencies is put forward,which needs establish COPT based on the scheduling results of each iteration,then search the representative contengencies based on COPT.The iteration will terminate unitl the prefined LOLPmax is satisfied.At last,the case studies verifies the accuracy and efficiency of the proposed method.Finally,on the basis of the previous chapter,wind power and load uncertainties are introduced,which causes scientificly distributing reserve become more complicated.In this paper,wind deviation is regarded as net load,so it can be used together with load fluctuation to form the probability distribution of net load deviation.After discretization of the probability distribution,LOLP expression is formulated combining unit outage events and net load deviation.LOLP constraint can be equivalently converted to a few representative constraints,and improved constraints addition method can be used to calculate this problem.When searching for the representative contengencies,based on the feature of the representative contengency constraints,improved method of searching the representative contengency is proposed,and its effectiveness is verified by the case studies.