Comparison of Grid-Forming Converter Control Strategies

Paper in proceeding, 2021

The aim of this paper is to compare three different categories of grid-forming converter control strategies based on their structural differences, and ability to fulfill the requirements that have been recently identified by the European Network of Transmission and System Operators for Electricity (ENTSOE). Among these requirements, the ones associated with the frequency characteristics of the converter system, such as its ability to prevent the risk for adverse control interactions, and act as a sink for harmonics are in focus. These properties are assessed through the frequency-dependent input-admittance models of the converter system. In addition, robust performance of the converter system at various grid strength is paramount, which is investigated both analytically and through detailed time-domain simulations in PSCAD.