A Review of Inertia Estimation in Power Systems Using Measurement-Based Approaches

Historically, the power grid has relied on conventional fossil, nuclear, and hydro-power generations, which used large rotating machines that provided ample inertia. However, as the grid transforms with the increasing penetration of inverter-based resources (IBR) like wind, solar photovoltaic, and battery storage systems, which lack inherent inertia, there is a growing need to reassess the role of inertia in the future grid. This shift raises concerns about maintaining system stability and security. In recent years, there has been a significant focus on the importance of inertia estimates in various areas such as robust frequency control, managing the integration of IBR, enhancing system reliability through fast frequency response analysis, and designing synthetic inertia as an ancillary service. This paper aims to provide insight into the impact of various measurement-based inertia estimation approaches on the evolving power grid. The estimation methods are classified into two categories: large disturbance-based methods and ambient data-based methods. This categorization highlights the strengths and weaknesses of different approaches, emphasizing the importance of the various approaches of inertia estimation.