Online condition monitoring of electrical power system imbalance

Symmetrical components are of great importance in many applications in electrical power systems, such as power protection and condition monitoring. This paper presents a computer-based algorithm for online symmetrical components estimation. The proposed algorithm uses the samples of the phase variables (currents or voltages) to estimate the magnitude and phase angle of each phase phasor at each sampling instant, and then these estimated phase phasors are used to formulate the symmetrical components as phasors and time-domain functions as well. Then the identified symmetrical components are used for condition monitoring of the electrical power system. Test examples of different power-system unbalanced conditions are computed to validate the developed algorithm.

Keywords: unbalanced conditions, electric power systems, protection systems, digital filters, symmetrical components, online monitoring, condition monitoring