Heuristic Inertia Estimation Technique for Power Networks with High Penetration of RES

Abstract

The inertia-less renewable energy sources (RESs) are potential to replace conventional synchronous generators with their associated inertias in the power system. The increased penetration of RESs into the grid will, therefore, lead to variability and unpredictability of system inertia due to stochastic nature of RESs. This paper, therefore, presents a heuristic technique to estimate the varying inertia in the power network using normal operating conditions. In this approach, phasor measurement units (PMUs) are used to extract data from the network and hence used to estimate the dynamic model representing the network. The higher order estimated model is then decomposed to lower order model for not only easy analysis and simplified inertia estimation process but also reduced computation burden. Contrasted to other approaches using large disturbance, the suggested technique can estimate inertia constant of the network using normal operating conditions. The technique has been tested using numerical simulations of a modified IEEE 14-bus network modelled in industry accepted DIgSILENT™ PowerFactory® tool.