N-1 Static Security Analysis For Electric-Gas-Thermal Integrated Energy System

The proposal of an integrated energy system has set off a new wave of energy reform.The integrated energy system is an important physical carrier of the energy internet,involve the conversion,distribution and organic coordination of energy.Under the integrated energy framework,the energy interaction between energy subsystems is more frequent.The multi-energy flow cooperative operation improves the operational energy efficiency,and make the traditional security analysis method for single energy subsystem difficult to apply.Focus on the static security of integrated energy systems with electricity-gas-heat,and use the static N-1 security analysis method to analyze the impact of coupling components under different working conditions on the security of integrated energy systems.The main research contents are as follows:First,study the steady-state modeling of integrated energy systems.Analyze the physical model of each subsystem of the integrated energy system from the perspective of multi-energy flow calculation,establish a steady-state model of an integrated energy system with power systems,natural gas systems,and thermal systems.Secondly,study the coupling characteristics analysis of integrated energy systems.For the coupling element,propose two control modes: the mutual control mode and the protection control mode,introduce the concept of two control methods in detail,analyze the advantages and disadvantages of the two control methods and application scenarios.Use the Newton method to decouple the multi-energy flow of the integrated energy system,get the system running status.The example analysis is performed by decoupling the multi-energy flow of the IES-4 system,it is verified that there are differences in the calculation results of the multi-energy flow in the two control modes.Finally,study the security analysis of integrated energy systems,establish an expected accident set including the coupling element and the proximal end branch of the coupling element.Static N-1 security check for each subset of the integrated energy system envisioned accidents,by analyzing the static N-1 security check results of the integrated energy system,explore the effect of the coupling element exiting operation and the coupling elements in different control modes on the operational security of the integrated energy system.The example analyze the N-1 static security result of the IES-14 system under different working conditions,verify the effectiveness of the proposed method.