DQ0 dynamics toolbox 

dq0screen

This is a free software tool for analyzing the dynamics of power systems based on dq0 signals. It is designed to simulate and analyze power systems that include several generators and loads, and possibly a large transmission network. The software provide tools for constructing dynamic models of the system components, and enables analysis in the frequency domain or the time domain. The manual and software provide simple explanations and examples that can help one get started.

The software is available here.