Nonlinear Hydro Governing Model and Improved Calculation for Determining Temporary Droop

The linear governing equations of L. M. Hovey are extended to describe the major nonlinearities of a hydro electric generating set. The resultant nonlinear governing model can be used to simulate the small and large signal transient response of an isolated generating set under any loading condition, and comparisons of such simulations with test results are given. The analysis of the paper demonstrates that Hovey´s method of calculating temporary droop from a closed dashpot step response transient is inaccurate, and a corrected method is presented.