Mid Long Term Production Cost Models And Methods In Power System Considering Renewable Energy Integration

With the increasing proportion of intermittent renewable energy integration,the power system increases the demand on operation flexibility and the traditional power system planning method based on electric power and energy balance is not applicable.It is necessary to carry out production simulation in fine time scale for a long period to reveal the details of the power system operation within the planning cycle and show the balance between supply and demand of operation flexibility,so as to provide basis and reference for the optimization of planning scheme.Mid long term production cost models have complex spatiotemporal structure and contain a lot of variables,which requires high computational performance but low computational accuracy.In order to ensure that the calculation cost can be greatly reduced under certain precision,this paper first presents a production cost model considering renewable energy integration based on security constrained unit commitment,which is suitable for mid long term production simulation.Considering the complexity of the model,the mid long term simulation is decomposed into several coupling short-term production cost models and the daily simulation of power system planning scheme is realized by the way of rolling iteration in this paper.Besides,using different optimization methods and different way of decoupling iteration in production cost models both have different effects on the simulation results.In order to evaluate this effect,this paper presents three decoupling iterative methods in time dimension.On this basis,five mid long term production cost simulation schemes are derived.Through the simulation of the RTS-96 system,the calculation speed and accuracy of different production models are compared,and the results of case study show that the coupling constraint between time periods and the coupling between running days have a great influence on the calculation accuracy and reasonable optimization model and decoupling iteration scheme can improve the solving efficiency while ensuring the accuracy of calculation.Clustered unit commitment has the characteristics of fewer variables,smaller search space and faster solution speed compared with traditional binary unit commitment.Based on this,this paper presents a production cost simulation scheme based on clustered unit commitment and daily rolling iterative calculation based on clustered unit commitment is realized by special treatment of boundary value of each iteration.Finally,through the simulation of RTS-96 system,the calculation speed and accuracy of clustered unit commitment and binary unit commitment are compared under the two conditions of whether or not network constraints are taken into account.The results show the effectiveness and applicability of the proposed model.This paper presents several mid long term production cost simulation schemes which can guarantee certain calculation accuracy and greatly reduce the calculation cost,and gives the applicable scope of different schemes,which is of great significance for the efficient development of mid long term production simulation in power system.