| In recent years,in order to reduce the energy shortage and environmental pollution caused by excessive consumption of fossil energy,a series of policies is introduced to expand the scope of "clean substitution" and increase the support for wind energy and other clean energy in China.As a kind of clean and renewable energy,wind energy has low cost of power generation,which is highly valued by the group of fertilizer and mineral industry in the period of coal industry transformation.However,due to the fluctuation of wind speed,the output of wind turbine also has the corresponding uncertainty,which is bound to have a great impact on the operation state of the power grid in the mining area.Therefore,it is of great practical significance to study the safety of the power supply system,to find the optimal capacity and to put forward feasible control measures in the mining area.Firstly,based on the actual data of feicheng mining area,the power transmission lines and transformer parameters are calculated.The mathematical model of wind turbine output is set up,and the correctness of the model is verified by simulation.According to the engineering practice,the influence of internal box variable reactive power loss on the power system in the mining area is considered,which lays a foundation for the following work.Secondly,in order to measure the safety of the power grid,this paper firstly establishes three indexes:voltage deviation,overall load rate of the system,and weighted power flow entropy.By using analytic hierarchy process(ahp),a comprehensive index is established to evaluate the security of power grid,the simulation results verify the effectiveness of the index.By analyzing the shortcomings of the traditional particle swarm optimization(pso)algorithm,local learning and reverse learning mechanisms are introduced to improve the pso,and the advantages of the improved pso algorithm are verified by comparing the improved pso algorithm with the former one.Taking the comprehensive safety index as the objective function,the improved particle swarm optimization(pso)algorithm is used to obtain the optimal grid-connected capacity of wind power,and the state of the power grid is analyzed.Finally,after the Wind-PV power plant connecting to the grid,the overall voltage of the system is low and some lines are overloaded,in combination with the practical situation of mine power grid,two control measures of reactive power optimization and power grid structure improvement are adopted to optimize the overall system voltage and overload lines.The simulation results verify the effectiveness of the two control measures. |
