AUTHOR=Huang Renzhi , Dong Chen , Wu Zaijun , Quan Xiangjun , Wang Zichen , Sun Tiankui , Hou Kai 

TITLE=A sigmoid-based adaptive inertia control strategy for grid-forming inverter to enhance frequency stability

JOURNAL=Frontiers in Energy Research

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2023.1095610

DOI=10.3389/fenrg.2023.1095610

ISSN=2296-598X

ABSTRACT=<p><bold>Introduction:</bold> This paper proposes a sigmoid-based adaptive inertia control strategy for grid-forming (GFM) inverter to enhance frequency stability.</p><p><bold>Methods:</bold> Firstly, the frequency response characteristics under different disturbances are analyzed theoretically. Then, to solve the problem that fixed inertia leads to a contradiction between the maximum frequency deviation and the setting time, a non-linear inertia regulator is investigated. This non-linear inertia regulator, which is based on an improved sigmoid function, is applied to achieve real-time inertia by the frequency deviation. Moreover, the full-order small-signal model of the system containing the nonlinear inertia regulator is established and thus the stability of the proposed strategy is analyzed.</p><p><bold>Result and Discussion:</bold> The proposed control strategy is implemented without derivative action, which may suffer from high-frequency noises. Finally, the hardware-inthe-loop (HIL) results verify the remarkable performance of the proposed control strategy.</p>