Study On Optimization Model And Method Of Generation Dispatching

Optimal generation scheduling is the basis for power system economic operation. First, aiming at day-ahead and real-time generation dispatching optimization model and method,this paper carried out a systematic and in-depth theoretical study, intended to improve the speed of generation scheduling optimization and the search for better solutions; Then, for actual needs of currently carrying out the energy saving based generation dispatching in china, this paper comprehensive studies the incremental loss calculation and analysis methods, and compensation programs caused by genertaion right trades of inter-province and trans-province.The research work has made the following key results:For further improve calculation performance and get better solutions of power generation scheduling optimization method, aiming at the mixed integer nonlinear programming problem of day-ahead unit commitment, based on the three main algorithms of the lagrange relaxation, mixed integer programming and benders decomposition, this paper designs the corresponding solving strategies. (1) Lagrange relaxation algorithm has a speed advantage for solving unit commitment, but is heavily dependent on the convergence and coordination of lagrange multiplier on master-slave issue, aiming at this problem, based on the traditional model of mixed-integer nonlinear unit commitment, this paper proposes lagrange relaxation algorithm based on modification of particle swarm optimization; Numerical example analysis shows that the algorithm achieves the optimal modification of Lagrange multiplier, the computation increased linearly with the increase of units, considers the computational speed and solution precision. (2) Mixed integer quadratic programming algorithm for solving unit commitment problem has global optimization capability, but for large-scale optimization problems, its computation speed and accuracy will be affected. Aiming at this problem, based on the model of mixed integer quadratic programming unit commitment, an improved mixed integer quadratic programming algorithm is presented;Numerical example analysis shows that the algorithm greatly reduces the complexity of solving the unit commitment, improving overall computational efficiency. (3) Mixed integer programming algorithm for solving security constrained unit commitment directly, will significantly reduce the computational efficiency, while using traditional Benders algorithm, existing algorithm shock and solution efficiency dropping because of the constrain by the size of the system. Aiming at this problem, based on security constraints unit commitment model under DC flow constraints, an improved Benders decomposition algorithm is presented. Numerical example analysis shows that in the premise of ensuring the computational accuracy, this algorithm control the searching direction of the Benders cut, reducing the optimization space of Benders algorithm, improving solving efficiency of the security constraint unit commitment optimization problem.For selecting the best realization ways of real-time dispatching, this paper establishes two real-time generation dispatch model which aim to minimum energy consumption and minimum the mount of adjustment. In accordance with the relevance of day-ahead generation schedule, four realization ways of real-time generation schedule are proposed. Through qualitative comparison in the procedure of developing generation schedule and quantitative calculation of the energy saving effect of different realization ways, this paper indicates that the choice of realization ways of real-time generation schedule aspects from the system security level, the goal of energy saving, the scheduling technology and other aspects, and intelligent generation dispatching is the best realization ways of real-time generation schedule,but it need to rely on the smart grid and dvanced automation technology.It is difficult for AC optimal power flow taking into practical use due to the constraints about the algorithm convergence and calculation efficency.Meanwhile,it is hard for the DC optimal power flow based on static loss correction to achieve the delicate balance of net loss and comprehensive energy consumption. Aiming at this this problem,in order to get more optimal solution of Practicality Real-time dispatching optimization methods, two coordinative optimization of network loss in security-constrained economic dispatching are proposed. Numerical example analysis shows that the methods have no relation to the operation patterns of power system,can retain the speed of DC optimal power flow and fully reflect the nonlinear characteristics of the power system.In accordance with annual or monthly genertaion right trades base on centralized multilater matchmaking transactions,the incremental loss calculation method is presented in this paper.The analysises of cases states that the theory calculation about incremental loss can reflect the actual effect on the loss of power system because of genertaion right trades.The loss shared with the generations who particates in the genertaion right trades is identical to the total incremental loss of power system.For the problem about how to define the responsibility for the losses caused by trans-province/regional genertaion right trades based on the centralized multilater matchmaking,the way for wheeling loss caucaltion and compensation is given in this paper. The method is proven to be reasonable and effective in view of pratical cases analysis.Morover, generation right trades under marginal clearing mechanism can't match the parties to the transaction clearly, which leads to define the responsibility for network loss compensation and transmission cost with great difficulty. This paper proposes the loss calculation and compensation methods on generation right trades under marginal clearing mechanism.Cases study indicates that the loss compensated is closer to the loss caused by physical flow of the transactions. The above research achievement has been put into application of power system in China.This paper proposes optimization method of day-ahead and real-time generation schedule,and incremental loss calculation and compensation method on generation right trade.lt not only has academic value, but also has a practical value for achieving the optimal allocation of power resources, and promote energy saving electric power industry.