Open-source tools for frequency-domain stability analysis of black-box and white-box AC/DC grids

The global shift toward renewable energy is accelerating the use of HVDC transmission, with today’s point-to-point links expected to evolve into meshed AC/DC grids—making stability assessment increasingly critical, especially given the need for modular methods that can accommodate black-box models. This paper addresses this need by presenting two open-source tools for black-box and white-box frequency-domain small-signal stability analysis of AC/DC power systems. Both tools are introduced with an overview of their functionalities and use cases. A methodology is then proposed that integrates the two tools to incorporate EMT black-box models into fast stability analyses with analytical models. Two case studies demonstrate the accuracy and practical value of the approach. Overall, the…