Research On Voltage Power Optimization Adjustment Of Distribution Network With Distributed Power Supply

With the rapid development of economy in our country,the electricity load is getting more uncertain and diverse and is more likely to lead to voltage quality problems.Distribution network as a part of the lowest voltage grade in power system is closely connected with the user side,and the quality of voltage is an important guarantee of normal operation of power system.The quality of voltage represents the level of power system operation and management,and affects the quality of industrial products and people's life.In the actual distribution network,the load develops and changes with the quick and unbalanced features on the time,as well as with the seasonal variations on the space character.The changes often make the voltage quality unqualified.To some extent,with the distributed source getting access into the grid,it could not only reduce the loss of the net,but also could solve the problem of low voltage.For example,when the load remains at peak in a day,the voltage may drop beyond the lower voltage limit in some area along with the heavy load and low power factor.If these area are connected with distributed power,then the problem of low voltage will be settled with the adjustment of reactive power.However,in some cases,the voltage of the whole grid will exceed the upper limit in the trough of the power utilization.If the grid id connected with distributed power,the access point could produce a large number of reactive power which will also make the voltage exceed the upper limit.Therefore,the distributed power and other means could coordinate the balance of the between voltage and power in distributed network.In view of the fact that the access of the distributed power into the grid will make the flow of the system change and become more complicated.In this paper,we will analyze the influence on the loss and voltage of net caused by distributed power,mainly in the type of node,capacity grade,space distribution and the permeability.The node type is divided into PI,PQ(V),PV and PQ node.The capacity level is displayed by the different type of distributed power in a same node.Spatial distribution could be reflected by the same type of distributed power with the equal capacity in some certain nodes.At last,the permeability is presented by the same type of distributed power in a few nodes in the grid.In this section,we will analyze the power flow calculation with distribution power,which is based and tested on the radiant IEEE 33 node system.In this paper,the optimal problem is a multi-object optimization problem of net loss and voltage deviation.The distributed power,the on-load voltage regulating transformer tap,and the reactive power compensation device are used to solve the problem mentioned.In general,the methods we have adopted are the quantitative optimization and vector optimization algorithm.For quantization algorithm,we could get the results of optimization,degree of convergence,computational time and other parameters by optimizing the multi-object problem with the genetic algorithm of artificial intelligence.For vector algorithm,first,we could transform the multi-object problem into the single-objective problem by normalized plane method.Then,the tracking interior point method is used to figure out the Pareto optimal solution set.Finally,we could get the comprise solution of multi-object optimization.These two methods will be stimulated on the IEEE 33 and 21 node system.Then we will also compare the computational time,the degree of convergence,optimized outcome,etc.