| With the increasingly serious energy crisis and environmental problems,distributed generation(DG)has attracted more and more attention of power companies in various countries because of its flexible generation mode,low investment cost and less pollution.Under the active management mode,combining the optimal allocation of distributed generation with its output control,the optimal allocation of reactive power compensation equipment,adjusting of on-load tap changer and interruptible load,the distributed generation can be more rationally allocated and the voltage quality of distribution network can be improved.In this paper,the location and capacity optimization of distributed generation(DG)connected to distribution network under active management strategy is studied.The main research contents are as follows:(1)In the existing optimal allocation model of distributed generation in distribution network,the different influence degrees of voltage deviation of each node on the objective function of total voltage deviation are not considered.To solve this problem,a multi-objective optimal allocation model of distributed generation in distribution network considering voltage weighting factor is proposed in this paper.The objective function of the model is total voltage deviation,total cost of installation,operation and maintenance of distributed generation and electricity purchase,as well as active power loss.By introducing a voltage weight factor into the objective function of the total voltage deviation of the model to reflect the impact of the distributed generation allocation on the voltage of each node or to reflect the evaluation of the user’s voltage quality requirements,the optimization process is conducive to the node with larger voltage deviation or the node with higher voltage score is easier to approach its expected voltage amplitude.Based on the Latin hypercube sampling,the distributed generation and load state are obtained.The proposed model is solved by the NSGA-II algorithm.The optimal scheme is optimized by the multi-objective grey target decision algorithm based on information entropy weighting.(2)In order to allocate distributed generation more reasonably,multi-scenarios are constructed based on Latin hypercube sampling and K-means clustering.Then,two optimization models are established by combining the optimal allocation of distributed generation and reactive power compensation equipment with active management measures such as output control,adjusting of on-load tap changer and interruptible load.Model 1 is a multi-objective model to realize the comprehensive optimal allocation of distributed generation and reactive power compensation equipment.It takes the total voltage deviation,the total cost of installation,operation and maintenance of distributed generation cost,purchasing electricity cost and the annual investment cost of reactive power compensation,as well as the active network loss as objective functions,and takes into account the adjustment of on-load tap changer.Model 2 is a single objective model to optimize active power output and power factor of distributed generation,and interruptible load.It takes active management cost,demand side management cost and renewable energy subsidy cost as objective functions.The two models are respectively solved by NSGA-II algorithm and optimal power flow algorithm based on interior point.The simulation example shows that the comprehensive optimization of distributed generation and reactive power compensation equipment based on active management strategy can fully play the role of distributed generation and reactive power compensation in improving voltage quality,reducing network loss,and improve the utilization of distributed generation on the premise of guaranteeing economy. |
