###### Abstract  
This work presents a new coordinated operation (CO) framework for electricity and natural gas networks, considering network congestions and demand response. Credit rank (CR) indicator of coupling units is introduced, and gas consumption constraints information of natural gas fired units (NGFUs) is given. Natural gas network operator (GNO) will deliver this information to an electricity network operator (ENO). A major advantage of this operation framework is that no frequent information interaction between GNO and ENO is needed. The entire framework contains two participants and three optimization problems, namely, GNO optimization sub-problem-A, GNO optimization sub-problem-B, and ENO optimization sub-problem. Decision sequence changed from traditional ENO-GNO-ENO to GNO-ENO-GNO in this novel framework. Second-order cone (SOC) relaxation is applied to ENO optimization sub-problem. The original problem is reformulated as a mixed-integer second-order cone programming (MISOCP) problem. For GNO optimization sub-problem, an improved sequential cone programming (SCP) method is applied based on SOC relaxation and the original sub-problem is converted to MISOCP problem. A benchmark 6-node natural gas system and 6-bus electricity system is used to illustrate the effectiveness of the proposed framework. Considering pipeline congestion, CO, with demand response, can reduce the total cost of an electricity network by 1.19%, as compared to \(-0.48\%\) using traditional decentralized operation with demand response. coordinated operation; natural gas network; electrical network; credit rank indicator +
Footnote †: journal: Medical  
limits pipeline operators from providing accurate guidance on gas quantities to supply gas-fired generators each hour [5]. In general, generators overschedule gas deliveries to ensure enough resources to operate. The inefficiency will only increase with the growing use of natural gas for electricity generation. While the two systems have operated for decades, closer coordination could save money, improve efficiencies, and minimize potential disruptions. Improved coordination of these networks will increase energy resiliency and reliability while reducing the cost of natural gas supply for electricity generation. Natural gas generation can reduce the use of coal-fired power, support integration of renewable resources, and reduce greenhouse gas emission. In power systems with increasing numbers of uncertain renewable sources, gas generation is taking a more important role in supplying short-term flexibility to match unexpected electricity consumption. In the electricity network, the natural gas generation units are rapid response units that overcome generation scarcity caused by sudden variations in the electricity consumption or the renewable generation dispatch. The gas turbines' flexibility relates to the gas network's flexibility [5]. The performance of the gas turbine is affected by some important parameters that consist of the compression ratio, ambient temperature, pressure, humidity, turbine inlet temperature, specific fuel consumption, and air to fuel ratio [6]. Reference [7] examined the renewable energy sources impact, including pumped-storage units and photovoltaic systems on power system security from electricity and natural gas networks perspective. With the large-scale natural gas infrastructure deployment, which leads to changes in capabilities of pipelines, operational procedures, supply, and tariffs, it is important to have coordination between the two networks to enhance future energy system reliability [8]. Natural gas volume is susceptible to price changes and influences the generation and commitment costs of generating units. Naturally, an increasing amount of natural gas usage in the electricity sector has raised difficulties for natural gas network planning and operation. Natural gas pipelines' pressure interruption or loss may contribute to the outage of several natural gas-fired generators and lead to power system security issues.