Cascade Optimal Operation Of Electric-Heat-Hydrogen Integrated Energy System Considering Refined Modeling

With the rapid socio-economic development,demand for energy is incereasing,making the problems such as imbalances of energy supply and demand,unreasonable energy structure,and large carbon emissions in energy production and consumption become further highlighted.The integrated energy system(IES)with multi-energy coupling and coordinated supply has become a key technology to alleviate the contradiction between energy supply and demand,and promote low-carbon energy consumption.At the same time,as a clean and efficient emerging energy,hydrogen energy can realize the deep coupling of electricity,heat,gas,cold and other energy sources,and form a novel generation of IES with hydrogen as the medium,which has attracted extensive attention of domestic and foreign researchers.The electricity-heat-hydrogen IES is based on meeting the user’s electricity,heat,cooling and other load needs.By connecting to energy equipment such as gas turbines,gas boilers,electrolyzers,and methane reactors,the electricity-heat-hydrogen IES can realize the coupled operation among various energy equipment and multi-energy complementation.However,the energy conversion efficiency of each equipment is different under specific working conditions.At present,the relevant research on the optimal operation of IES has not sufficiently considered factors such as the energy efficiency characteristics of the equipment and the user’s requirements for energy supply and consumption.In order to effectively exert the utility of hydrogen in IES,reduce the carbon emission of system,enhance the system economy of running,this paper focuses on refined modeling,energy cascade utilization and low-carbon operation,and studies the IES cascade optimization operation strategy.The main work is as follows:(1)Based on the energy supply structure of the electricity-heat-hydrogen IES,the energy input and output conversion relationship of IES is analyzed,and the energy coupling model of electricity-heat-hydrogen IES is established.Secondly,considering the specific energy supply and consumption characteristics of different IES equipment,the energy conversion efficiency of equipment under specific operating conditions is analyzed,and refined models of key energy equipment are constructed,which include electricity/heat energy supply equipment,hydrogen energy utilization equipment,and energy coupling equipment.The above research provides a theoretical basis for the follow-up IES low-carbon optimization operation research.(2)The energy demand of different grades is analyzed,and according to the energy cascade utilization principle,the system cascade energy consumption relationship is studied from the overall,and the system energy forms are divided into electric load,cooling load,steam load,high heat load,medium heat load and other multi-grade loads,and the main cascade energy consumption mode of the system is planned.On this basis,combined with the refined model of key energy equipment,aiming at the optimal system energy cost and operation and maintenance cost,and considering power balance constraints,equipment output constraints,an IES cascade optimization model is constructed to achieve high-efficiency utilization of energy corresponding to the grade.(3)Taking the participation of flexible loads in the optimal operation of IES as the starting point,fully considering the characteristics of flexible loads in IES,an electric/thermal flexible load model including electric/thermal shaving loads and electric/thermal transferable loads is established.Secondly,combined with the cascade optimization method and the refined model of IES key equipment,and taking the cost of external energy,operation and maintenance cost,carbon penalty cost,and flexible load adjustment compensation cost as optimization goals,a low-carbon optimization operation method of IES considering flexible load is proposed.Finally,the electricity-heat-hydrogen IES is taken as the research object,and the simulation and comparison with the traditional cogeneration energy supply method and rigid load dispatching method are carried out.The low-carbon optimization operation method of IES considering flexible loads effectively exerts the utility of hydrogen energy,reduces the carbon emission of the system and reduces the operating cost,and can provide theoretical and technical guidance for the rational use of energy and operation management of the system.Under the background of "carbon emission peaking and carbon neutrality",in order to reduce environmental pollution and improve energy utilization efficiency,systematic research work has been carried out on the refined modeling of IES key equipment,energy cascade utilization,and flexible load.The research results can provide an effective reference for the safe and economical operation of hydrogen energy connected to the energy system,and the efficient cascade energy consumption of the energy system.