Power system nonstationarity and accurate power system identification procedures

Power system nonstationarity is the main source of errors in the system analysis and description with the use of DSP. Accurate and advanced DSP has to be used for power system identification. It is based on high resolution DFT, well known from its ideal accuracy for coherently sampled signals. As the power system is nonstationary such conditions are violated. In this paper the principal sources of errors in real power system DSP measurements are presented. The DSP methods of identification, insensitive to power system nonstationarity are proposed and verified with simulations and experiments. Few examples of results of real system identification are shown to inform the reader on actually assured identification accuracy.