Optimization Of Reactive Power Configuration In Distribution Network With Distributed Generation

A large number of distributed generation accessing to the distribution network have an effect on not only the distribution power supply quality but also the planning,design,and operation of distribution network.Reactive power allocation optimization of distribution network is an effective method to improve the quality of power supply,reduce the loss of network and improve the stability of the system.The different types of distributed generation have different output characteristics,therefore the traditional distribution network analysis algorithms needed to be improved.Thus it is important to establish the optimal reactive power configuration model with distributed generation and to find the optimized algorithm.The influence of the interconnection location and capacity of distributed generation on power flow distribution and network loss of distribution network is analyzed qualitatively.According to the interconnection and control characteristics of different DG,the DGs are divided into PQ node,PV node,PI node and PQ(V)node.On this basis,the power flow calculation of DG-containing distribution network is carried out with the improved forward-backward sweep method.Under consideration of load fluctuation and DG output,the paper establishes the mathematic model,which includes the objective function and constraint condition.The former is sum of the minimum cost about energy loss and equipment investment in three kinds of operation scenarios,and the latter includes power balance,the limit of the node voltage and the non-excess reactive power.In order to improve the search efficiency,to reduce the computational quantity and to avoid “the dimension disaster”,the reactive power optimization algorithm have been put forward which combines the following two parts.The network loss sensitivity analysis method has been used to affirm the compensation point order,and the particle swarm optimization algorithm have been used to determine the compensation capacity.The implementation process of the algorithm is given.Based on the above algorithm,the reactive power optimization program of distribution network with distributed generation isredacted.Validation of the optimized model of reactive power configuration and the algorithm is carried out with examples of IEEE33 distribution system and some real distribution network.The results show that the algorithm can effectively solve the problem of reactive power allocation optimization with distributed generation.The optimization solution concluded is reasonable and feasible.