Defining the instantaneous power of alternating current during electromechanical transients

The problem of defining the instantaneous active and reactive power is relevant for improving the power system control and investigating the dynamic processes taking place in power systems. Today, there is no technique to obtain these values at a sampling rate corresponding to one of the initial measurements of current and voltage. The technique was developed for defining the instantaneous active and reactive power under steady-state conditions and during transients as well. The technique performance was analyzed in detail involving the mathematical simulation results along with the STC UPS JSC physical electrodynamic power system model measurements. The developed technique has been designed as a mean of solving the problems of the power system control and analyzing the dynamic processes taking place in power system as a whole as well as in its separate elements. It allows, for example, deriving the electrical load static and dynamic characteristics based on the digital fault recorders (DFRs) data. The technique meets the requirements to processing speed and is capable for real-time operation.