Font Size: a A A

Research On Island Partition Of Distribution Network With Microgrid

Posted on:2020-07-07Degree:MasterType:Thesis
Country:ChinaCandidate:H Q HuFull Text:PDF
GTID:2392330578455263Subject:Power system and its automation
Abstract/Summary:PDF Full Text Request
In the context of large-scale power outages in distribution networks,isolated islands formed by microgrids and loads can guarantee critical load power supply and improve the reliability of power supply for important users.However,the output of wind/PV and load demand fluctuate strongly during the operation of the island,which is not conducive to the safe and reliable operation of the island.In view of this problem,this paper studies the partitioning strategy of islands in the fault of distribution network in the operation scenario where the new energy output is not clear.Due to the particularity of islanding,this paper first clarifies the principle of islanding partition,that is to restore non-critical loads as much as possible under the premise of prioritizing the protection of critical load power.Aiming at the uncertainty of the wind/PV output,a method of static island partition for distribution network based on risk reserve is proposed.The method preferentially restores the power supply of the critical load,and then introduces the risk power indicator to evaluate the ability of the island to supply power to the outside,and adopts an active integration method to improve the power supply reliability of the power supply islands to restore other non-critical load power.The simulation results show that the proposed method has obvious effects on improving the reliability of power supply,load priority search ability and island operation flexibility.Aiming at the characteristics of the island's Wind/PV output and fluctuation of load demand,a multi-period dynamic island partition method based on island unbalanced power curve is proposed.By removing the controllable load and using the unbalanced power curve peak sequencing strategy,the method can reduce the energy storage backup power capacity and increase the energy storage main power capacity on a time scale.The simulation results show that the islanding scheme formed by this method has fewer changes,and it is beneficial to improve the system's ability to recover the load under the premise of ensuing the reliability of the restored load.In addition,in order to improve the degree of aadaptation between the power supply of the island and the active power of the load,the islanding operation is optimized to avoid the occurrence of load shedding.A dynamic island partition method considering transferable load is proposed.The island has the largest equivalent load,the lowest operating cost and the highest reliability as the optimization target,and solves the multi-objective problem by adaptive weight PSO and obtains the optimal islanding scheme.The simulation results show that only considering the transferable load can meet the needs of islanding,which can further improve the adaptability between the active power output of the island and the load demand,and optimize the working state of the energy storage system.
Keywords/Search Tags:island partition, distributed network, microgrid, multi period
PDF Full Text Request
Related items