Small‐signal modeling and tuning of Synchronverter‐based wind energy conversion systems

Abstract

The Synchronverter technique is an example of a virtual synchronous machine‐based control method for PWM controlled power electronic converters that enable converters to mimic the behavior of a synchronous generator (SG). It is based on the well‐established mathematical model of an SG and should equip converter connected generation with the capabilities of providing the grid with ancillary services such as frequency/voltage support due to the inherent capabilities of the SG. In this paper, the Synchronverter control method is applied to a wind energy conversion system (WECS) connected to the grid using back‐to‐back converters. The mathematical models of the control system for both the rectifier side and the inverter side are elaborated and used to derive the required transfer functions. A tuning procedure is proposed, using the transfer functions of the system, to enable a fast and easy adaption of the control method to power systems with different parameters. Simulations have been performed to validate both the functioning of the proposed tuning procedure and the ability of the WECS to provide the grid with ancillary services. The results are promising, showing the controllers yielding fast and accurate responses to contingencies and changes in power set‐points without steady‐state deviations.