Defining the instantaneous power of alternating currentin electromechanical transients


The problem of defining instantaneous active and reactive power is relevant for the purpose of investigating the dynamic processes taking place in power systems.


To date there is no technique allowing to obtain these values at a sampling rate corresponding to one of the initial measurements of current and voltage. Mathematical analysis and digital signal processing methods including Hilbert transform have been involved to develop the technique by our specialists.


In order to prove the effectiveness of the developed technique experiments have been carried out using mathematical simulation. The simulation has been performed by means of MATLAB software package. Initial data for the detailed research have been obtained from physical electrodynamic power system model.


The technique has been developed for defining the instantaneous active and reactive power under steady-state conditions and during transients as well. The technique performance has been analyzed in detail involving mathematical simulation results along with physical electrodynamic power system model measurements.


The developed technique is designed as a mean of analyzing dynamic processes taking place in power system as a whole as well as in its separate elements. It allows to derive 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 of real-time operation.