An Improved Control Scheme for Grid-forming Inverters

Abstract

In order to reduce the reliance of power grids on conventional (and often non-renewable) generation, reliable and dispatchable converter-interfaced distributed generators (DGs) are required. Instead of relying on large rotating machines for frequency and voltage regulation, it becomes crucial to develop improved control schemes for grid-forming inverters. In this paper we propose a simple and effective frequency and voltage control scheme that offers desirable dynamic response and power sharing. The proposed controller is compared to the conventional hierarchical control scheme via a stability analysis of the overall system dynamics and time-domain simulation results. It is shown that the transient performance and the stability properties are significantly improved.