Optimal Dispach Strategies Of Power Flow For Distribution Network With Micro-source

With the development of distributed generation technology,renewable micro-sources in the future power grid get more and more attention.As the scale expansion of the power grid and the increasement of the voltage level,the coordinated operation of the distributed generation technology with micro-sources and large power grid is the development trend of the future power grid.When the micro-sources access to micro-grid,the topologic structure and the power flow of distribution network have a great change.On the one hand,The distribution network structure turns into a multi-micro-source weak-ring network from single-power radiation network.On the other hand,it has a great impact on power flow scheduling.Based on the stability of the system operation,it is important to dispatch the power flow reasonably and optimize the economic and environmental value in the distribution network with micro-sources,which has a great engineering value and practical significance.In this paper,the output characteristics of wind turbine,photovoltaic cell,micro gas turbine,battery and fuel cell are analyzed,their mathematical models are constructed.On this basis,the influence of these distributed genaration on power quality,power generation plan,loss and system protection are analyzed.The power flow calculation of the distribution network with micro-sources is studied based on the traditional power flow calculation when micro-sources connected distribution network according to certain principles.Also,this paper made a practical power flow analysis with the standard IEEE 33 nodes model,and compare the results whether the PV source is involved,shows the influence of micro-source access grid on voltage level is given.According to the mathematical model of each micro-source,an optimal dispatching model of distribution network including multiple micro-sources is established,which is a multi-objective optimization problem.The model has the objective function of economic cost and environmental cost and the constraint conditions with the power balance,the output of micro-sources,the spinning reserve capacity and other conditions.Finally,the non-dominated sorting genetic algorithm with elitist strategy is proposed based on the NSGA,which is used to solve the power flow scheduling model proposed in this paper.In the end of this paper,the example of IEEE-33 bus is used to verify the proposed scheduling model.A daily scheduling model is taken into the research object.the start-stop sequence and the output plan of each unit are given by the NSGA-II,and the coordination function of the micro-sources is analyzed from the aspects of power purchase consumption and total cost.