Reliability Assessment Of Integrated Energy System Considering Demand Response

With the development of social economy,the problem of energy shortage and environmental pollution is becoming more and more serious.It is an effective solution to develop renewable energy,improve energy utilization efficiency and realize the complementarity of various energy sources.In recent years,with the increase of user demand and the strengthening of energy coupling,it is urgent to transform the power supply,gas supply and heating/cooling systems that operate independently in the traditional sense.A variety of load resources on the demand side also bring challenges to the coordination and optimization of coupling systems.Therefore,this paper studies the dynamic characteristics of the multienergy coupling system and carries out reliability assessment of the integrated energy system considering demand response.The main research contents are as follows:Firstly,the architecture of integrated energy system is constructed and the energy flow among different energy subsystems is described.Establish the mathematical model of energy production,conversion and storage equipment,including wind power,photovoltaic,gas turbine,gas boiler,combined heat and power unit,electric refrigerator,electricity/heat storage equipment,etc.,and describe the working principle and function of each equipment.Based on the system fine modeling,the energy flow distribution and balance in power grid,natural gas network and heat/cold network are analyzed,and the delay characteristics of temperature transmission in heat/cold network are studied.Secondly,according to the dynamic characteristics of multi-energy coupling system,markov process is introduced to describe the running state of each energy equipment,and the two-state model of independent equipment and the multi-state model of coupled equipment are established.The probability and expected value of power supply shortage,which are the traditional power reliability indexes,are used as the assessment indexes,and the assessment indexes are extended to other energy supply subsystems.According to the delay characteristic of temperature transmission,the delay time of temperature load fault transmission is proposed to improve the accuracy of fault identification.On the basis of considering dynamic characteristics and time series,a Markov Chain Monte Carlo method for multi-energy coupling system is proposed.The feasibility and efficiency of the proposed method are verified by example simulation,and the reliability of the system is improved by the combined operation of multi-energy subsystems and the consideration of temperature load fault transmission delay.Finally,based on the traditional power demand side response,the integrated demand response of multi-energy coupling system is studied.The demand side load is classified,including cuttable,translatable and transferable load.On this basis,an optimization assessment model that considers integrated demand response is established,with the goal of minimizing total operating cost,and the constraints of power balance,equipment operation restrictions,and line capacity conditions.The system was solved by CPLEX+YALMIP,and the reliability of the system was evaluated after the response.The simulation results show that the integrated demand response not only has good economic and environmental benefits,it can also effectively improve the reliability of the coupling system.