Research On Hierarchical Collaborative Operation Control Technology Of New Distribution Syste

With the increasing depletion of traditional fossil energy sources and the growing demand for electricity,renewable energy generation has become mainstream.Photovoltaic(PV)power generation,as a typical renewable energy source,has become one of the widely used power generation methods because of its safety,cleanliness and efficiency.However,when more and more distributed PV is connected to the distribution system,the tidal flow of the traditional distribution system changes from one-way flow to two-way flow,which makes the system power backflow and voltage overrun problems more and more serious.In addition,the difficulty of system operation control is greatly increased due to the scattered installation,large number of distributed PVs and unstable power output.In view of the above problems,this paper focuses on the research work on the new distribution system hierarchical cooperative operation control method containing a high percentage of distributed PV,and the main work is as follows.(1)According to the working mode of PV inverter and the voltage regulation principle of PV system,a solution is proposed to solve the voltage overrun problem caused by the high proportion of distributed PV connected to the distribution system.The principle of the standard Alternating Direction Method of Multipliers(ADMM)is introduced and improved,and the mathematical model of the synchronous type alternating direction multiplier method is constructed.(2)A new distributed reactive-active co-operative operation control method is proposed for the operation control problems caused by the high proportion of distributed PV connected to the distribution system.First,the distribution system is partitioned using an improved k-means clustering algorithm;second,the operation control model of the distributed PV distribution system is constructed and convexified with the objective of minimizing network losses;then,a multi-partition distributed cooperative operation control framework based on the synchronous ADMM algorithm is constructed based on the "decomposition-coordination" principle.Finally,the effectiveness of the proposed method are verified by simulation.(3)A new distribution system hierarchical voltage cooperative control method is proposed for the increasing scale of control nodes and the limitations of the traditional partitioning algorithm in the future new distribution system,as well as the problems of the number of iterations required by the distributed algorithm and the large amount of communication data.First,the distribution system is partitioned using an improved modularity function partitioning algorithm.Secondly,a hierarchical voltage cooperative control model is constructed with the objectives of minimizing PV active reduction,network losses and node voltage deviation.Then,a two-layer voltage control method with intra-area autonomous and inter-area distributed coordination is proposed,and both of them cooperate rapidly for voltage control through hierarchical cooperation.Finally,the effectiveness of the proposed method is verified by arithmetic simulation.