| Integrated energy system is an effective way to promote accommodation of distributed renewable energy and strengthen coupling utilization of multi-type energy,serving as a flexible distribution-sale role in market environment.Whether it can improve the system’s electricity-gasheat multi-energy complementary optimization performance,and open up internal and external linkage transaction barrier,is directly related to economy and market operation level of integrated energy system.Combined heat and power is the core part of energy production in integrated energy system.Therefore,based on initial demand for preferential accommodation of renewable energy such as wind power,a closed-loop multi-energy complementary optimal dispatching scheme consisting of gas generation by wind power – combined heat and power by natural gas and hydrogen – power generation by waste heat recovery is proposed in this paper,aiming to improve comprehensive energy utilization rate of the system.At the same time,in view of the increasingly open market environment,a day-ahead and real-time clearing method of integrated energy system is proposed,with which energy producer,system operator and load aggregator linkage superior grid and spinning reserve provider to interact among multi-market members.After completing economic innovation at energy production side,a balanced allocation in dual market of energy and benefit will be researched.Above all,analyzing transformation mechanism of electricity – gas,gas – thermal power,and heat – electricity in integrated energy system,mainly involving economic feasibility analysis,principle discussion,and technical feasibility analysis here.Then,selecting some important variables to briefly analyze control characteristics of coupling equipment such as electrolysis cell,methane reactor,fuel cell,gas turbine and organic Rankine cycle power generation in multi-energy transformation process.Based on one-to-one correspondence between external output and internal control,building the variable efficiency mathematical model of each unit,which makes dispatching be of more credibility and adjustability.Hereafter,constructing a multi-energy complementary optimal dispatching model that includes the above transformation process.The energy loss cost of electricity-gas-heat converted into standard coal loss is introduced into objective function,and other innovative element such as comprehensive energy utilization rate that simultaneously quantify two attributes of energy "quantity" and "quality" is also introduced into constraints.Then,compiling the program in majorization software named GAMS and adopting general reduced gradient algorithm to solve the nonlinear optimization model,thereby the economy and efficiency of the proposed optimal dispatching scheme are verified through example system of coupling 6-node power grid,6-node natural gas network,and 6-node heat network.The above research is mainly aimed at internal unit optimization of energy producer,which only represents one market role in market environment,and cannot reflect the interaction with other members.Thence,this paper adds more market elements,in which discussesing market composition members and corresponding functions in integrated energy system,and analyzing the effect of market mechanisms such as competitive power supply,mutual insurance contract,spinning reserve service,and demand response on each market member.Then,based on above market elements,a day-ahead and real-time clearing process is developed,and the clearing decision models for energy producer,system operator and load aggregator are built respectively,accordingly giving the variables transmission relationship among each member and market equilibrium condition.Ultimately,choosing a thermoelectric integrated energy system that is applicable to China’s current energy market to construct example,which shows various market mechanisms have an effective role in refinement of energy distribution and benefit balance. |
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