Unambiguous power system dynamic modeling and simulation using modelica tools

Abstract

Abstract-Dynamic modeling and time-domain simulation for power systems is inconsistent across different simulation platforms, which makes it difficult for engineers to consistently exchange models and assess model quality. Therefore, there is a clear need for unambiguous dynamic model exchange. In this article, a possible solution is proposed by using open modeling equation-based Modelica tools. The nature of the Modelica modeling language supports model exchange at the "equation-level", this allows for unambiguous model exchange between different Modelica-based simulation tools without loss of information about the model. An example of power system dynamic model exchange between two Modelica-based software Scilab/Xcos and Dymola is presented. In addition, common issues related to simulation, including the extended modeling of complex controls, the capabilities of the DAE solvers and initialization problems are discussed. In order to integrate power system Modelica models into other simulation tools (MATLAB/Simulink), the utilization of the FMI Toolbox is investigated as well.

Equation-based modeling of three-winding and regulating transformers using Modelica

“…The Modelica equation-based modeling language is objectoriented and open-source, which allows model implementation directly from mathematical equations. This is an important characteristic, which implicitly decouples the model from the mathematical solver, thus providing unambiguous simulation results among different tools [2]. The attractive features of this language have been successfully applied in different areas such as the automotive and aerospace industry [3].…”

Equation-based modeling of FACTS using Modelica

“…Modern electric power systems are one of the most complex networked systems, their role is to ensure continuous supply of electricity. For the planning and operation of this complex networks, modeling and simulation are essential to satisfy operational requirements or planning constraints [1], [2]. Power system models used in time-domain simulations can be categorized into different types: Electro-Magnetic Transient type, Phasor Time Domain type or Quasi Steady State type [3], [4].…”

“…The modeling approach may also vary depending on the kind of studies to be performed or the simulation's solver. In the later case, a particular choice of solver may influence the modeling approach, making it difficult to evaluate the quality of the model among different tools that are used for the same kind of studies [1].…”

“…This is because a Modelica model is decoupled from any mathematical solver. Taking into account this characteristic, a Modelica model accepts modifications in its equations and its parameters, and provides unambiguous simulation results among different simulations tools [1].…”

A modelica power system library for phasor time-domain simulation

“…A previous version of the library [2] was developed in Scilab/Xcos simulation environment during the European project PEGASE (see [2]). Scilab/Xcos has several limitations in the support of Modelica language specification [6]. Therefore, for the iTesla project each component block inherited from PEGASE into the Power Systems library was converted from Scilab/Xcos models to the most recent Modelica language definition by using Dymola.…”