Inertia Identification and Analysis for High-Power-Electronic-Penetrated Power System Based on Measurement Data

With the gradual increases in the use of wind power and photovoltaic generation, the penetration rate of power electronics has increased in recent years. The inertia characteristics of power-electronic-based power sources are different from those of synchronous generators, making the evaluation of inertia difficult. In this paper, the inertia characteristics of power-electronic-based power sources are analyzed. A measurement-based inertia identification method for power-electronic-based power sources, as well as for high-power-electronic-penetrated power systems, is proposed by fitting the frequency and power data. The inertia characteristics of different control strategies and corresponding control parameters are discussed in a case study. It was proven that the inertia provided by power-electronic-based power sources can be much higher than that provided by a synchronous generator of the same capacity. It was also proven that the inertia provided by power-electronic-based power sources is not a constant value, but changes along with the output power of the sources.