| The integrated energy system(IES)is of great significance for improving energy efficiency,promoting the consumption of renewable energy,and energy saving and emission reduction,has caused widespread concern in the global energy field.However,the integrated energy system is mostly based on clean energy such as natural gas and renewable energy.The cost of energy supply is significantly higher than the cost of traditional coal-fired energy.Poor economy is a major problem faced in its initial stage.Based on this,this paper considers the flexible electric/heat load in the capacity configuration stage of the system,and considers the addition of electric-to-gas equipment to reduce the initial cost.And in the operation stage,considering the carbon transaction cost and the uncertainty of renewable energy,the operation of IES is optimized to improve the economy of the system.The main contents are as follows:(1)For IES including wind turbines,photovoltaic units,gas turbines,electric boilers,electricity storage and heat storage equipment,the capacity configuration of IES is optimized by considering flexible electric/heat loads.Consider the translational load,the transferable load and the reduced load to establish a power flexible load model;establish a thermal flexible load model according to the user's ambiguity of temperature perception.The mixed integer linear programming method is adopted to optimize the configuration of the system with the goal of the smallest economic cost and the least primary energy consumption to obtain the best capacity of each device and the output of each device in each period.Through case analysis,it is verified that comprehensive consideration of flexible electrical load and flexible thermal load to participate in system capacity optimization configuration can improve system economy,reduce primary energy consumption,and increase renewable energy penetration by flexibly dispatching flexible electrical loads and adjusting indoor temperature.(2)For the IES with electric-to-gas equipment and gas storage equipment,the capacity configuration of the system is optimized.Optimizing the configuration of IES with the lowest cost and the lowest energy consumption as the optimization goals.Using the augmented epsilon constraint method,the multi-objective optimization is transformed into a single-objective optimization,and the mixed integer linear programming method is used to solve the problem.Case analysis shows that the introduction of electricity-to-gas equipment in the integrated energy system can not only improve economy,but also convert excess renewable energy power into natural gas,promote the consumption of renewable energy,and increase the installed capacity of renewable energy.(3)In view of the uncertainty and environmental protection of renewable energy in IES,the system is optimized for operation.Considering the uncertainty of renewable energy under the carbon trading mechanism,IES is optimized for interval operation.The interval number is used to express the uncertainty of wind speed and solar radiation intensity.According to the carbon trading mechanism,the cost of carbon trading is added to the economic target.Aiming at the lowest operating cost,the IES interval operation optimization model is established.Through a case analysis,the system's operating costs,taking carbon transaction costs into account,can improve the economy of the system.Promote wind power and photovoltaic absorption,in which the effect of promoting photovoltaic absorption is better than that of promoting wind power absorption.Reduce the purchase of electricity from the grid and the purchase of natural gas.The effect of reducing the purchase of electricity from the grid is better than the effect of reducing the purchase of natural gas.The fluctuation of wind speed and solar radiation intensity has a greater impact on the power purchase of the grid and the adjustment power of the power flexible load,but has a lower impact on the purchase of natural gas. |
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