An Equivalent Dynamic Gas Network Model with Electricity–Gas Systems

Abstract

As the coupling relationship between a natural gas system and electricity system deepens, the gas generator set will cause the fluctuation of natural gas systems while meeting the variation in demand of the electricity system. In order to quantify the impact of gas demand uncertainty for gas the generator set on the natural gas systems, an equivalent dynamic natural gas network model is presented in this paper. By introducing the concept of electrical analogy, the natural gas transmission equation is established, so that the gas flow in each pipeline is coupled to be calculated simultaneously. The disturbance factor of a gas demand change in an electrical system is introduced into dynamic modeling of gas networks, and the equivalent dynamic natural gas network model is developed. The proposed model effectively expresses the explicit dynamic response relationship between the pressure at a node and the gas demand of gas-fired generators in the form of an analytical formula, which can sufficiently reflect the dynamic performance of a natural gas system under disturbance of the electricity system with the action of electricity–gas coupling, laying the foundation for dynamic analysis of the electricity–gas system. Case studies on a 5-node natural gas network and the integrated electricity–gas system consisting of a 10-node natural gas network and IEEE 14-bus system indicate that the equivalent dynamic model is capable of effectively describing the dynamic response relationship.