A Research Code for Dynamic Power System Simulation and Analysis

This paper presents a versatile, Matlab-based simulation and analysis code for electric power systems. The code was created for basic research and designed from a control/dynamical systems perspective. Full advantage was taken of Matlab's inherent cell arrays, structures, vectorized- calculations, ODE solvers with event handling and complex arithmetic. Design features that make the code easy to use and expand as well as several example analysis tools are outlined. Keywords—power system simulation and analysis, Matlab I. I NTRODUCTION Motivated by the desire to study power system behavior, researchers and educators have developed a variety of soft- ware applications that perform power system simulation and analysis. Inspiration for many of these applications can be found in the "closed" nature of commercial packages, broad availability of computational resources and popularity of high-level scientific programming languages such as Matlab, Matlab/Simulink, and Modelica. Matlab's wide acceptance, graphing capabilities, toolboxes and vector-oriented approach have made it a common platform (1), (2), (3), Simulink's graphical interface to Matlab prompted its choice when a more intuitive interface was desired (4), (5), and the object- oriented modeling language Modelica was chosen to create a library and graphically-driven interface (6). The Matlab-based simulation and analysis code summa- rized in this paper was created to study electric power systems from a dynamic system and control theory perspec- tive. Design goals were to 1) have a versatile and evolving program accessible by researchers at the source code level to quickly and effectively add new model components, and implement and experiment with analysis tools and 2) provide numerical efficiency to allow simulation of moderately large systems on the order of hundreds of busses and thousands of states. This paper reports on the basic features and the various simulation and analysis tools that have been designed and implemented. Section 2 provides an overview of the code and its capabilities and section 3 summarizes example applications of analysis tools.