Inertia estimation in modern power system: A comprehensive review

The worldwide motivation to use renewable energy sources and power electronics interfaced electric drive loads has not only reduced the power system inertia constant but has resulted in fluctuations in its value over a wide range. Low and varying values of inertia might cause frequency stability problems, and hence, needs to be monitored and controlled. With the intermittent operation of grid-connected renewable energy sources, accurate inertia estimation (IE) and forecasts are challenging. Inertia estimates are crucial for robust frequency control, managing renewable energy penetration, improved system reliability through fast frequency response analysis, and market design of synthetic inertia as an ancillary service, etc. A lot of attention has been devoted to IE over the recent years. This study aims to explore the several IE methods and tries to identify the key challenges that make it one of the most popular issues in power system stability. This review attempts to discover the main difficulties in various IE algorithms along with their key features. Finally, future directions and possibilities in IE are discussed briefly.