Research On Multi-objective Dispatch And Decision Method For Power System With Multi-type Power Stations

The continuous expansion of hydro,wind,solar and other renewable energy power stations has promoted the diversified development process of power supply structure in China's power system.However,due to the uncertainty of natural conditions and the rapid development speed,the hydro,wind and solar power consumption of some regional power grids is seriously hindered.The construction of transmission projects such as"west to east power transmission" alleviates the power abandonment problem of hydro,wind and solar power stations to a certain extent,but how to coordinate the conflict of interests among interconnected power grids has become an urgent multi-objective optimization problem.Therefore,it is of great practical significance to carry out the research on multi-objective optimal dispatch and decision-making method of power system with multi-type power stations and seek the optimal planning and dispatch scheme for optimizing the power structure and improving the renewable energy consumption capacity.This paper takes the power system with multi-type power stations as the research object,focuses on the power planning,dispatch scheme optimization and decision-making,and the main research achievements is as follows:(1)Research on mid-long term power planning model of power system.In view of the deficiency that the traditional power planning model can only consider a single type of supplementary power station,a mid-long term power planning model which can consider multiple types of supplementary power stations at the same time is proposed.The goal of the model is to minimize the sum of the investment cost of the supplementary power station and the total fossil energy consumption cost of the system in the operation period.In the case of power shortage,hydro thermal wind and solar four types of power stations can be considered at the same time,which expands the application scope of the model.According to the characteristics of the model,a nested POA-DPSA is designed,which alleviates the dimension disaster and reduces the calculation difficulty.The application results show that the traditional power planning model is only a special case of the proposed model,and the proposed model can obtain the optimal combination of various types of supplementary power stations.(2)Research on short-term optimal dispatch of power system considering hydro wind and solar power consumed locally.The calculation method of abandoned hydro power is proposed;considering the problem of renewable energy consumption,the abandoned hydro,wind and solar power is converted into the penalty cost,which is added to the total cost objective of the traditional model,and the short-term optimal dispatch model of power system with hydro wind and solar power stations is improved;two linearization methods of typical nonlinear expressions are proposed,and the model is linearized by using this method,so that it can be converted into the standard mixed integer programming model which can obtain the optimal results by using professional linear solver.The calculation results of Yunnan regional power grid show that compared with the results of traditional model,the improved model can greatly improve the degree of renewable energy consumption under the premise of minimum total cost.(3)Research on multi-objective optimal dispatch of interconnected power systems considering hydro wind and solar power consumed outside.Considering the different stakeholders in interconnected power systems,a multi-objective optimal dispatch model for the system is established based on the minimum operation cost of each grid.In order to solve the problem that the convergence result of NMOPSO is infeasible when solving the model with complex constraints,a rolling correction strategy(RCS)is designed to correct the infeasible solution in the iterative calculation process,which makes the algorithm always search the optimal solution in the feasible region,so that RCS-NMOPSO is proposed.RCS-NMOPSO is used for example analysis,and according to the comparison results with other algorithms,it shows that the Pareto optimal solution set obtained by the improved algorithm can give consideration to both feasibility and superiority.(4)Research on the decision-making of multi-objective optimal dispatch scheme for interconnected power systems.Aiming at the decision-making failure problem of Mahalanobis distance TOPSIS when the covariance matrix of the evaluation matrix is irreversible,the regularization method is used to modify the covariance matrix,and it is proved that the modified covariance matrix must be reversible,and then the improved Mahalanobis distance TOPSIS is proposed;the evaluation index system of multi-objective optimal dispatch scheme for interconnection power systems is constructed.The decision-making of multi-objective optimal dispatch scheme for an interconnection system of three regional power grids is taken as an example,improved Mahalanobis distance TOPSIS is used to rank the evaluation schemes,and the best scheme is obtained finally.The universality of the improved method is illustrated by referring to the results of comparative analysis.