Flexible Inertia Optimization for Single-Phase Voltage Source Inverter Based on Hold Filter

With the increasing penetration of renewable energy sources (RESs) in the power system, voltage source inverters (VSIs) are widely used as the power electronic interface of the RESs, which will decline the inertia of power system. The insufficient inertia has been becoming a big challenge for the modern power system. Synchronverter (SV) technology can operate the inverter mimic the characteristic of the synchronous generator to provide virtual inertia. However, the virtual inertia of conventional SV is associated with the frequency stability, which limits the inertia that can be provided. Taking the analysis of single-phase SV as an example, this paper proposes a flexible inertia optimization method for single-phase VSIs based on the inertial characteristic of hold filter, which gives a new degree of freedom for the optimization of single-phase VSIs inertia. In this way, the inertia of single-phase VSIs can be adjusted more freely according to system requirements without affecting the frequency stability. Furthermore, the effects of the proposed method on the system dynamic characteristics are investigated. Finally, simulation and experimental results are given to verify the feasibility and feature of the proposed inertia optimization method.