User defined controllers in power system stability analysis using PacDyn 8.1 simulation tool

This paper presents the small-signal stability analysis of a power system using PacDyn 8.1 simulation tool. PacDyn is a comprehensive small-signal stability analysis package which was developed by CEPEL. This software package supports built-in as well as user defined models. The user defined models are investigated and results compared to those obtained using traditional built-in models for excitation systems. A single machine equipped with an automatic voltage regulator (AVR) and a power system stabilizer (PSS) and connected to an infinite bus power system model is used as a test system. Eigensolution (Modal analysis) results, time domain as well as frequency domain simulations are compared to validate the findings of the investigations. The results showed that built-in models are computationally efficient, well-defined with fixed structures while user defined models offer unlimited model structures with additional dynamic variables that can be monitored during simulations. Results for both modal, time domain and frequency simulations showed slight variations in results when using built-in and user defined models.