Theoretical Study On Minimum Control Node Set For Controllability Of Multi-Energy Flow Network

With the development of society and technology,the structure of energy transitions from single traditional energy to multi-source clean energy.This causes the energy to be mixed and transmitted in the form of multi-energy flows in the network,forming a hybrid energy system coupled by multiple sources of energy.In order to achieve the safe and stable operation of this complex hybrid energy system,it is particularly important to have a minimum control input configuration for meeting the controllability requirements.This paper mainly studies the problems of minimum control input of multi-source power flow network,minimum control node set,and location selection of redundant controller considering actual controllability constraints based on graph theory,classical control theory and operational research theory.The specific research contents are as follows:1.Based on the state space model of the microgrid established by the droop control,the minimum control input,the corresponding simple form of the control matrix and the controller with minimum energy which satisfy the controllability conditions are configured.Recognizing that the minimum control input at the different cut-off frequency of low-pass filters is reduced by half compared to the same cut-off frequency,and when reaching the same desired state,the control energy consumed by the control matrix corresponding to this configuration is relatively low.This indicates the direction for the control design of the cut-off frequency of the real microgrid and lays the foundation for the study of the minimum control node set for a hybrid multi-energy system;2.Based on the system matrix determined by the energy flow relationship of the multi-source energy flow network,a method for identifying the minimum control node set that can control the multi-source energy flow network is proposed.In order to obtain a group of control nodes that meet the controllability of a multi-source power flow network,the algorithm of prioritized matching and adding appropriate directed edges are proposed because a minimum driving node set obtained by a random maximum matching algorithm may have partially invalid driver nodes.The proposed algorithms ensure that there is no invalid driver node in the final set of minimum control nodes.3.From the point of view of location-control path integration,the problem of expanding location selection of redundant controllers for multi-source energy flow network is studied.Under the premise of capacity constraint of the controller,the location of the control center of the new investment is optimized,and the control paths between the system state nodes and control centers(including the previously existing and newly added control centers)make the minimum total control energy,and the genetic algorithm is designed reasonably and the optimal location of control center is obtained.Finally,the paper summarizes the main research content and the need to further explore the content of the study.