Multi-rate simulation of integrated electricity and gas systems: formulation of algorithm and equivalent circuit model for network simulators

Abstract

The emergence of multi-energy networks, comprising electricity and natural gas (NG), presents novel and complex challenges to the comprehensive analysis of energy systems. Energy systems based on electricity and gas adhere to distinct physical laws and mathematical representations. As attention and interest in integrated electricity and gas systems (IEGS) grow, expanding the scope of applying electrical analogies to pneumatic quantities is advantageous. The objectives of this paper are to implement the extension of this analogy and to conduct a multi-rate simulation of IEGS. It shows how the NG pipeline and gas compressor station (GCS) can be modeled using basic electric elements for the simulation of pneumatic transients. The primary objective of devising the multi-rate algorithm is to attain greater efficiency during the computational procedure. The target system is partitioned into an electrical network subsystem (ENS) and a gas network subsystem (GNS). Different time steps are adopted in the simulation of these subsystems. A novel interface model based on gas turbines is proposed to represent the interactions between ENS and GNS. A comparatively large time-step size is used in the GNS for accelerated computations. The multi-rate simulation algorithm is accompanied by validation and application to demonstrate its effectiveness in enabling efficient simulation of IEGS.