All-day Reactive Power Optimization Of Active Distribution Network Based On Reactive Cost Analysis

With the shortage of resources and the intensification of environmental pollution,environmentally-friendly distributed generators are increasingly being put into the operation of the distribution network.In view of the various advantages and disadvantages brought by them,people have established The concept of "active distribution network".In the active distribution network,because the characteristics of the reactive power output of various distributed power sources are different from each other,the traditional generator model cannot be generalized.Therefore,the reactive power optimization of the active distribution network must be optimized Seriously.On the other hand,in the context of deepening power market reforms,the idea of cost control is gradually gaining popularity,then reactive power can no longer be simply a subsidiary of active power,ignoring the existence of its costs unilaterally.So,in the reactive power optimization process of the distribution network,only using the active network loss as a criterion for the economic performance of the power grid,it is no longer possible to accurately measure the cost of system reactive power optimization.An accurate economic indicator should be an objective function that can include both the active network loss and the reactive power output cost.After summarizing the research status of reactive power optimization in active distribution network and in the background of power market,according to the output characteristics of various distributed generators and reactive power compensation devices in active distribution network,this paper analyzes and establishes their respective reactive cost models.Then two intelligent algorithms,harmony search algorithm and model annealing algorithm,are introduced.In view of the advantages of harmonic search algorithm,and the disadvantages of easy to fall into local optimization,the simulated annealing algorithm is used to improve it,and an improved harmonic annealing algorithm with excellent optimization ability is constructed,which is verified by standard test function and reactive power optimization examples.Finally,based on the consideration of reactive power cost,the objective function of all day reactive power optimization considering the operation economy and stability of the active distribution network is established by using the entropy weight distribution method,and the upper and lower limits of the output of each reactive power source are discussed.In the modified IEEE 33 node standard test system,the calculation example of all day reactive power optimization is verified.The results show that After calculating the reactive power cost,the optimization cost can be greatly saved while ensuring the stability.