Low-Carbon Optimization of Electric and Heating Integrated Energy System with Flexible Resource Participation

The modern energy system is in the low-carbon transition stage. However, due to the randomness and volatility of renewable energy, it is difficult to integrate into the grid and the low-carbon process is limited. Integrated Energy Systems (IES) focus on meeting the demand for interaction between supply and demand. In recent years, increasingly resources on the load and energy storage side have begun to participate in the low-carbon operation of the system, but the resource synergy advantage has not been fully utilized, and there is a lack of analysis on the flow and transfer of carbon emissions in IES. To solve these problems, this paper proposes a low carbon optimization model of electric and heating integrated energy system considering the participation of flexible resources, analyzes the improvement effect of multiple flexible resources response on the comprehensive benefits of the system, and visually presents the flow process of electric thermal carbon emissions topologically, promoting the efficient consumption of low carbon energy in IES. First, analyze the industrial load regulation mechanism of differentiated layout in the regional power grid, and establish the model of cogeneration unit, electric heating equipment, electric/thermal energy storage and controllable load in the electric-thermal coupling system based on the urban energy grid. Then, a comprehensive benefit model is built with economic cost, wind and solar usage and carbon emissions as indicators, and a carbon emission flow topology is proposed to describe the carbon emission flow information attached to the energy flow. Finally, the electric-thermal coupling energy system is simulated to obtain the regulatory results of flexible resources and carbon emission flow information in different resource allocation scenarios. In this model, the improvement effect of flexible resource participation response on the comprehensive benefits of the system is analyzed from the perspective of economy and low carbon, and a more comprehensive evaluation model is formed by visualizing the flow process of electric and thermal carbon emissions through topology. In the IEEE 33 node distribution network and 45 node heat network coupling system, different scenarios are divided according to the flexible resource composition for simulation. The results show that under the collaborative regulation of resources on the load storage side, compared with the scenario without flexible resources, the economic cost is increased by about 8.1%, the wind and solar usage rate is increased by 7.9%, and the carbon emissions are reduced by 10.8%. Through the reasonable conversion of energy storage operation mode, the power supply burden of traditional high carbon emission power supply units is reduced. The participation of industrial controllable loads has effectively expanded the flexible resources, reducing the peak valley difference by 17%, further promoting the consumption of solar energy and reducing carbon emissions. The topology analysis of carbon flow in typical periods of the operation cycle shows that the carbon emission topology of wind and solar energy in IES can be extended to more load nodes in the system through the storage and redistribution of low carbon and excess energy, and the reasonable electricity production transfer of industrial users, thus reducing the node carbon emission intensity and the total carbon emissions in the operation cycle. The following conclusions can be drawn from the simulation analysis: (1) The flexible resource model can describe the adjustment characteristics of energy storage and the industry specific industrial load regulation characteristics, and can make policy based on the resource type. (2) By optimizing the flexible resource operation scheme, the benefits of IES in terms of economy, wind and solar usage rate and carbon emissions can be improved, and diversified optimization schemes can be provided within feasible areas. The carbon emission flow model adopted can accurately describe the carbon emission flow process of IES in the operation cycle. (3) Through flexible resource control, it can promote the penetration of low-carbon energy in IES, reduce the use of energy-intensive energy, and help achieve the economic operation of the system in a low-carbon environment. © 2023 Chinese Machine Press. All rights reserved.