Open-Source Power System Dynamic Models and Test Cases in Modelica: an application example.

The dynamic behaviour of modern power systems has become more complex since significant changes due to inverter-interfaced technologies were introduced. The need for comprehensive analysis of complex dynamics have resulted in the emergence of open-source solutions that, in contrast to traditional commercial tools, grant power engineers full control and visibility of dynamic models and solvers that are needed for planning and operation. This paper aims to bring the attention of the power system community to the development of open-source tools based on the Modelica language. An illustrative example is presented, and simulated with OpenModelica, using the IEEE test system for voltage stability assessment which considers not only short - but also long-term dynamics that require careful consideration. It uses the Modelica library of Dyna$\omega$o, a hybrid C++ /Modelica open-source suite of power system simulation tools. The illustrative test case can be downloaded from the Dyna$\omega$o open-source GitHub repository.