Research On Optimal Power Flow Of Distribution Network With Distributed Generation

Distributed power supply access distribution network,changes the distribution network structure and operation mode,so that the original power flow distribution,node voltage,network loss is affected,proposed a second-order cone relaxation technology containing a variety of grid-connected types of distributed power distribution network optimal current method.The nonlinear output power constraint of distributed power supply is transformed into second-order cone regularization problem,and the distribution network trend of four types of distributed power supply with PQ,PV,PI and PQ(V)is solved accurately and efficiently.A large M method is used to transform the reactive power cross-boundary automatic conversion problem of PV distributed power supply into a mixed integer optimization problem.The simulation results show that the distribution network power flow calculation method based on second-order cone relaxation can effectively deal with multi-node and multi-type distributed power supply,and has higher solution accuracy than the two approximate processing methods.The optimal configuration model including DG distribution network is established with the aim of minimum active network loss and minimum voltage offset.Through a number of test scenarios,it is shown that the second-order cone relaxation method proposed in this paper has very high precision and has the ability to solve multi-type DG multi-region optimization configuration problems.It is found that the proper adjustment of the power factor of DG can significantly reduce the system loss,the use of multi-DG dispersion configuration is better than the single DG centralized configuration of the reduction effect,after increasing the voltage offset quality optimization target,the voltage distribution can be more flat,significantly improve the system voltage quality.The simulation results of IEEE33 node and PG&E69 node distribution system are used to verify the feasibility and effectiveness of the proposed method in this paper.In order to ensure the safety constraint of branch voltage and current,considering the energy storage device,the discrete reactive power compensation capacitor acts on the constraint of distribution network,the optimization goal of multi-time active network loss is optimized,and according to the prediction of DG output and load curve,the reactive power optimization under multi-time period is studied,and the simulation experiment of PG&E69 node system Verify the validity of the proposed method.The second-order cone relaxation algorithm is used to solve the optimal distribution network reconstruction with distributed power supply,introduce three kinds of acceleration constraints,reduce the search range and decrease the calculation time,and several test scenarios show that the proposed second-order cone relaxation method has the ability and very high accuracy to deal with the global optimal reconstruction of different types of DG.The paper has 33 figures,23 tables and 52 references.