Research On Distributed Synergistic Optimization Of Electric Power And Natural Gas Flows With Multiple Decision-Makers

In the future energy Internet environment,the power system and the natural gas system will be highly integrated.The coupling and interaction between the two systems is more frequent.If the impact of the intersystem interaction on the two systems will be ignored,the optimization results will be overly optimistic.Therefore,it is necessary to carry out synergistic optimization of electric power and natural gas flows with the interaction into consideration.Meanwhile,the actual optimal operation and scheduling of power and gas systems are often in their own affairs.The strong coupling of electric power and natural gas has made the dispatching management of electric power and natural gas systems more difficult.Therefore,it is necessary to study the theory and method of distributed synergistic scheduling for the integrated energy system,so as to realize the comprehensive utilization and complementary synergy of the electric power flow and the natural gas flow,and maintain the security and economic operation of the electric power and natural gas integrated energy system.The main research contents and achievements in this paper include:(1)A steady state model of a system level "coarse grained" electric power and natural gas integrated energy system is constructed with the operating characteristics of the electric power flow and the natural gas flow into consideration.And a steady state model of node level "fine grained" electric power and natural gas integrated energy system is constructed based on Energy Hub.The non convex constraint(Natural Gas Pipeline flow model and coupling element model,etc.)is converted to convex constraints for preprocessing of the steady state model of the electric power and natural gas integrated energy system based on the incremental piecewise linear(INC)and the second-order cone relaxation(SOCR)technology.(2)Based on the interaction characteristics of the boundary energy of the electric power and natural gas system and the analysis of the operation and management form of the electric power and natural gas integrated energy system,a hierarchical coordinated optimization framework which satisfies the scheduling management form of system level with regulatory center is proposed with the actual situation of the autonomous dispatching management of the electric power and natural gas two systems and only supporting a small amount of information interaction into consideration.The coordinated optimization scheduling problem of electric power system and natural gas system is managed by the superior coordinated center and the subordinate system scheduling center(power system dispatching center and natural gas system dispatching center).At the same time,the hierarchical distributed coordinated optimization scheduling model and method based on the analytical target cascading(ATC)and the master-slave alternating direction multiplier(MS-ADMM)are studied,so as to realize the decentralized autonomous and centralized coordination management of the electric power and natural gas integrated energy system.Garver6-GAS7 and IEEE118-GAS90 two electric power and natural gas integrated energy systems are selected to verify the effectiveness,rationality and scalability of the proposed hierarchical distributed coordinated optimization framework and optimal scheduling model and solving algorithm.(3)On the basis of the research of hierarchical distributed coordinated optimization scheduling,a new kind of peer-to-peer distributed coordinated optimization framework that satisfies the scheduling management form of system level without regulatory center,in which situation the third party supervision institutions is omited and power system dispatching center and natural gas dispatching center interactive directly and decentralized autonomous and coordinated,is proposed.At the same time,considering the diversity of communication modes in the peer-to-peer optimization framework,two kinds of electric power and natural gas flows distributed coordinated optimization scheduling models and methods are proposed based on the serial alternating direction method of multipliers(Gauss-Seidel mode,GS-ADMM)and parallel alternating direction method of multipliers(Proximal Jacobian mode,PJ-ADMM)to solve the optimal scheduling scheme of the electric power and natural gas integrated energy system.An example analysis is carried out on two electric power and natural gas integrated energy systems of Garver6-GAS7 and IEEE118-GAS90.(4)On the basis of system level multiple decision-makers distributed coordinated optimal scheduling of the electric power and natural gas integrated energy system,the node-level distributed coordinated optimal scheduling problem of the electric power and natural gas integrated energy system with multiple decision-makers based on the energy hub is studied.A node level electric power and natural gas flows decoupling mechanism and a node level distributed coordinated optimal scheduling framework are proposed.Meanwhlie a node level distributed coordinated optimal scheduling model and a solution algorithm with multiple decision-makers based on MS-ADMM algorithm are constructed to relize the decentralized autonomous and centralized coordination management.The optimal energy flow simulation of the node level electric power and natural gas integrated energy system,which is connected by 6 Energy Hub,verifies the correctness and effectiveness of the proposed node-level distributed coordinated optimization framework and the optimal scheduling method with multiple decision-makers.