Power system modal analysis tool developed for industry use

Common power system disturbances are characterized by oscillations that either damp out, sustain or grow. This oscillatory response can be measured and analyzed to extract modal information of the system. A previous paper by the authors examined the modal content of data with an approach motivated by the theory of normal form analysis. This paper reports on significant advancements made since that time. The primary advancement has been the inclusion of a variable projection nonlinear optimization technique. A user-friendly tool has recently been developed and tested by power industry members for analysis of real power system data. This paper details practical issues associated with this modal analysis tool, including solve-time speeds, initial condition estimation, model order selection and data-detrending.