Dynamic Modeling and Interaction of Hybrid Natural Gas and Electricity Supply System in Microgrid

Abstract

Natural gas (NG) network and electric network are becoming tightly integrated by microturbines in the microgrid. Interactions between these two networks are not well captured by the traditional microturbine (MT) models. To address this issue, two improved models for single-shaft MT and split-shaft MT are proposed in this paper. In addition, dynamic models of the hybrid natural gas and electricity system (HGES) are developed for the analysis of their interactions. Dynamic behaviors of natural gas in pipes are described by partial differential equations (PDEs), while the electric network is described by differential algebraic equations (DAEs). So the overall network is a typical two-time scale dynamic system. Numerical studies indicate that the two-time scale algorithm is faster and can capture the interactions between the two networks. The results also show the HGES with a single-shaft MT is a weakly coupled system in which disturbances in the two networks mainly influence the dc link voltage of the MT, while the split-shaft MT is a strongly coupled system where the impact of an event will affect both networks.Index Terms-Dynamic modeling, hybrid natural gas and electricity system (HGES), interaction, microgrid, microturbine (MT), natural gas network.

A Summary of the Main Contents and Existing Problems in the Study of Multi-Energy Coupling in Energy Internet

“…(Figure 2) The power-natural gas (electricity/gas) network as the main energy network in the integrated energy system, the interaction between it has long been concerned by the academic community, in which the literature [7] proposed a natural gas-power hybrid system dynamics model, and studied the interaction between power network and natural gas network in their transient process. In the literature [8], from the point of view of energy supply reliability, the transmission delay and compressibility of natural gas are considered, and the short time optimization operation of the electric/gas coupling system is studied.…”

Identification of microturbine model for long-term dynamic analysis of distribution networks

“…One important direction of the MT modelling is to conduct mechanism analysis, using available packages in commercial software, such as DIgSILENT, PSCAD and MATLAB/Simulink [18,22,23,24,25,26] For example, Rowen proposes a gas turbine mechanical model in [22], which describes the thermo- 40 mechanical process of the MT prime mover. In [23], the correlation between the electro-mechanical and thermo-mechanical subsystems is modelled.…”

“…Hence, natural gas flow is incorporated into the thermo-mechanical model of gas turbines in [26]. An improved MT model is developed to reflect the interactions between power and natural gas systems [18]. However, in practice, MTs may have different brands and capacities.…”

Robust Speed Tracking Control for a Micro Turbine as a Distributed Energy Resource via Feedback Domination and Disturbance Observer

“…With fast response and high efficiency feature, micro turbine (MT) is considered to be one of the most ideal candidates to be included in the hybrid renewable energy generation systems, such as maintaining the customs side power requirement by coping with peaking demand [1][2][3][4]. It is also well known that MT system employs complex dynamics, bringing about technical challenge in control design and stability analysis.…”

“…It is also well known that MT system employs complex dynamics, bringing about technical challenge in control design and stability analysis. Proportional-integral methodology is generally utilized to control the output speed of the MT system [4][5][6], with fewer novel controller designed based on the improved model constructed in work [7].…”