Research On Optimal Allocation Of Distributed Power Supply Based On Security Boundary Of Distribution Network

In the context of a high proportion of renewable energy generation that are connected to the grid,a large number of new components will be introduced into the distribution system,which makes the system nodes and branches have bilateral power flow characteristics.The strong uncertainty caused by the multi-temporal coupling of these components and the change of system stability mechanism caused by the trend of high electrification brings new challenges to the traditional distribution system planning methods.Safety has always been an important factor in the planning and operation of distribution systems.The concept of the safety boundary of distribution systems proposed in recent years provides a new theoretical method for the future operation of distribution systems.The focus of this paper is to solve the problem of optimal allocation of the distributed power supply based on the security of the distribution system.Based on the security boundary of the system,a two-step optimal allocation method of distributed power supply was proposed.The first step of the method is to solve the safety boundary by the mathematical model of the traditional counterpart of the distribution network,to obtain the safety distance of the current working point.According to the radar image of the system feeder safety distance,the feeder screening index was established,and the feeder with weak security was configured with distributed power supply.In the second step,an improved particle swarm optimization(PSO)algorithm was used to solve the distributed power configuration scheme,taking network loss,voltage offset,and voltage stability margin as objective functions.Resulting from the original system configuration according to optimization of active power distribution system,considering the effects of distributed power supply to the system,an access to the active power distribution system after the distributed power supply security boundary mathematical model was set up,giving a safe distance from the solution method of the active power distribution system,get the results and the corresponding solutions and the security of the original system is compared and analyzed.The rationality and correctness of this method were verified by the simulation results of a standard example.Afterwards,the method was extended to an actual grid example for further verification.Through the comparison of the solutions of several examples,it could be seen that the two-step optimal configuration method proposed in this paper effectively improved the overall security,as well as the matching degree of the grid structure and capacity,and reduced the network loss and voltage offset of the system.