Planning Research And Simulation Analysis Of Distributed Generation In Distribution Network

With the rapid development of national economy and the continuous improvement of living standards,people have more and more strong awareness of energy conservation and environmental protection.As a powerful measure to solve the contradiction between energy consumption and environmental protection,clean renewable energy power generation has been widely concerned and studied by scholars at home and abroad.Distributed generation（DG）has the advantages of low carbon,environmental protection,flexible control,and low investment cost,but its output is random,which will increase the complexity and uncertainty of power grid operation after grid-connected operation.Reasonable planning in the distribution network can effectively improve the power flow distribution,improve the node voltage quality,and reduce the network loss.If the planning is not reasonable,it may also cause problems such as increased loss and decreased node voltage quality.The main work is as follows:（1）The probability models of wind and photovoltaic DG output and system load fluctuation are established.The Monte Carlo simulation method is used to calculate the power flow distribution of distribution network considering the randomness of source and load sides.PG ＆E69 node system is selected as the test example.By setting two different DG planning schemes,the influence of different configuration capacities on system voltage and network loss and other operation indexes is analyzed.（2）The distribution network DG bi-level programming model is established by hierarchical calculation of distributed generation location and sizing problem.The upper location model determines the DG installation node according to the active power loss sensitivity method.The lower configuration model takes investment benefit,system voltage and active power loss as evaluation indexes,and establishes a multi-objective optimization model,which is solved by multi-objective grey wolf optimization algorithm.At the same time,the comprehensive satisfaction evaluation index is constructed to assist decision makers to select the best planning scheme.PG ＆ E69 node system is selected as the test example to analyze the voltage exceeding limit and the change of network loss of different planning schemes from the perspective of probability.At the same time,the planning scheme under different load capacities and the change trend of system voltage and network loss are discussed.（3）On the basis of the model in the third chapter,the active management measures are introduced into the lower configuration model to improve the coordinated control ability of the system and realize the optimal control of the source-load side power generation resources.The active management measures include adjusting the tap of on-load transformer,removing the active power output of DG and adjusting the power factor of DG.PG ＆ E69 node system is selected as the test example to analyze the changes of system voltage and network loss before and after considering the active management measures from the perspective of probability.The simulation results show that the active management measures have obvious effects on improving the system operation level,and the fluctuation range of system voltage and network loss is smaller.