Distributed System Planning And Optimization Control Of Regional Energy Internet

Regional energy internet is a distributed and complex system with deep integration of energy and information.If different energy systems are planned and operated independently,it will result in the low energy utilization,weak self-healing ability,and low system reliability.Therefore,scientific reasonable planning methods and operation strategies are essential for the global efficiency and economy of distributed multi-energy systems.Because the system planning and operation optimization of a distributed multi-energy system is a large-scale mixed integer nonlinear optimization problem,it is difficult to be solved by a centralized manner.Besides,the uncertainty and randomness of renewable energy generation and load demands increase the complexity of the problem.According to the transmission loss and energy balance,the coordinated planning of multi-energy,including clustering partition and network reconfiguration,is realized based on the decomposition-coordination theory.Following that,according to the different spatiotemporal decoupling characteristics of optimization objectives,a distributed hierarchical optimization strategy is implemented to reduce the complexity and coupling of multi-energy system’s operation optimization.In order to correct the optimal dispatch deviation caused by the forecasting error of renewable energy generation and load demands,the rolling horizon optimization method is introduced.The main research and innovation work of this paper are as follows:1)Distributed energy and loads have the characteristics of large quantity,small capacity,wide distribution,and time variability.In order to realize the reasonable configuration of different energy infrastructures and reduce the long-distance transmission loss of energy,a clustering partition optimization model based on transmission loss and energy balance is proposed innovatively.Simultaneously,the traditional k-means algorithm is optimized and improved to realize the reasonable partition of large-scale distributed energy and loads,as well as the location optimization of energy hub,by the pre-determination of cluster center’s number and the optimal selection of initial cluster centers.2)On the basis of achieving reasonable partition of large-scale distributed energy and loads,as for the interconnection of distributed energy and loads within and between regional energy networks,a distributed energy network reconfiguration method based on improved minimum spanning tree algorithm is proposed to build an economical and reliable energy internet,by realizing the star-branch topology planning within regional energy networks and the mesh topology planning between regional energy networks.3)Based on the above,the operation optimization of regional energy internet is need further consideration.In order to adapt to the plug-and-play of distributed energy,and solve the multi-energy complementarity and demand response of regional energy internet under multi-source,multi-load and multi-state operation modes.A peer-to-peer autonomous distributed hierarchical control strategy is proposed,based on different spatial and temporal scales of the optimization objectives.In the day-ahead scheduling of a long time scale,a variable dispatch factor representing energy allocation is introduced to optimize the energy hub model,and to realize the economic dispatch of multi-energy.Considering the prediction error of renewable energy generation and load demands,a daily scheduling based on model predictive control is proposed,and the ability of storage to participate in the system energy balance over a long period is ensured,by introduce the weight consensus of day-ahead scheduling and daily scheduling.In the short time scale,as for the voltage deviation reflecting power quality and the power real-time optimal allocation,an SOC-based voltage/current double-compensated distributed adaptive droop control is proposed innovatively,to achieve the adjustment of voltage deviation and current allocation.Considering the spatial decoupling characteristics of optimization objectives and the information privacy of different regional energy networks,as well as the real time and asynchrony of energy transmission,a distributed energy routing control method based on market transaction is proposed innovatively.In order to achieve the end-to-end power transmission and congestion managements,a minimum loss path with no congestion is selected for the specific energy trader by the intelligent electricity router based on the shortest path algorithm.4)To verify the effectiveness of the proposed operation optimization strategy,the hardware in the loop simulation technology is used to study the operation optimization of distributed multi-energy systems,and a scaling method is proposed and applied to solve the problem that the capacity or power level of physical device does not match the simulation object.Through the established hardware-in-the-loop simulation platform,the effectiveness of the proposed optimal control strategy is verified and displayed partly.