Abstract
The assessment of transients in
electrical systems requires numerical solving of systems of ordinary
differential equations with the main purpose of localizing the relative extrema
of state variables and of characteristic quantities in closely correlation with
the selected state variables. Searching for relative extrema is traditionally
performed immediately after the numerical integration is accomplished by
sequentially processing a large file containing the amount of data recorded at
all steps of numerical integration. Considering that, within the available
software environments, the state variables time-related derivatives are usually
discarded during numerical integration, finding approximations for the relative
maxima and minima of each characteristic quantity could become a complex
problem related to mathematical optimization. In this context, the present
paper advances a simple procedure for real-time localizing of relative extrema
of state variables and of the various characteristic quantities correlated with
state variables by employing a high-order explicit linear multistep method.
Computer experiments will be carried out by considering the more elaborate case
of a synchronous generator subjected to sudden three-phase short circuit fault.