Individual-based Modeling And Simulation For Integrated Energy System

In nowadays and future society, a variety of energies, including fossil energy, nuclear en-ergy, solar, wind and terrestrial heat, etc., will be used fully to meet the energy sustainabledevelopment of society. Considering the close relationship of different energy systems and thecoordinated complementary and integrated optimization of different forms of energy, an inte-grated energy system making up of electric power system, natural gas system, distributed ener-gy station and water heating network is put forward to deal with these questions in this paper.As a unified energy framework, the integrated energy system includes vast devices and equip-ments with their own properties, behaviours as well as different interactive activities, which israther complex to be solved with conventional approaches. Thus, this paper also develops anindividual-based complex system modeling method(IBCSMM) and is applied to the modelingand simulation of integrated energy system.As the first part of this paper, the main characteristics and two core definitions of IBCSMMare discussed detailedly, and the universal individual-based model(IBM) is described in a formallanguage. Then, the computer implementation model of individual is realised with the abstractarchitecture of an agent.In order to verify the validity and feasibility of IBCSMM, a small heating water systemis modeled with this approach. Detailedly, solar water heater, gas-fired water boiler, electricwater boiler, supply water pipe, return water pipe and heating load in the heating water systemare respectively modeled with different individuals. Furthermore, some negotiation interactionactivities between these individuals are simulated on the hybrid platform of Swarm for Java andMatlab. As a result, the optimization operating of the water heating system is achieved and thedata results are almost the same to those from conventional mathematical method.In the main part of this paper, an integrated energy system making up of electric powersystem, natural gas system, distributed energy station and water heating network is built to re-search the comprehensive utilization of different kinds of energies as well as the relationshipand interactive behaviour of the internal different energy subnets. After a detail introduction ofthe system’s physical structures, properties and operation modes, the integrated energy systemis divided into four high-level individuals and many low-level individuals, in which individu-als for electric power system, natural gas system, distributed energy system and water heatingnetwork are described clearly in the aspects of formalization expression and inner mechanisms.Finally, simulation experiments are undertaken based on the individual-based model ofthe integrated energy system. Specifically, according to the electricity, heat, gas demand ofterminal users, distributed energy station and water heating network are optimized together toachieve the minimum energy costs when taking the following into consideration: heat loss ofwater heating network, power consumption of circulating water pumps, electricity price andgas price. And then the electricity purchased from electric power system and the natural gaspurchased from natural gas system can be determined. At the same time, optimal power flowof electric power system is solved when achieving the minimum fuel costs; optimal gas flowand pressure distribution in the natural gas pipeline network are acquired when achieving itsminimum energy consumption. The simulation results reflect the great significance of cascadeutilization of energy and the capability of integrated energy system to improve the efficiency ofenergy utilization. Also, the mutual effects and interactive behaviours between different energysubnets in the integrated energy system are presented and the capability of IBCSMM is verifiedonce again.