Grid Strength Metrics and Evaluation in Converter-Dominated Grids

Research Project, 2019 – 2020

With a lower amount of synchronous generation and growing proportion of power-electronic converter interfaced renewable generation and transmission, such as wind turbines, solar photovoltaic and HVDC links, it is problematic that the short-circuit capacity based metrics and inertia constant are directly applied to evaluate the grid voltage and frequency strength. The main aim of the project is to re-evaluate classical metrics and propose new suitable metrics for evaluating the stiffness of the grid voltage and frequency in a power-electronic converter dominated power grid. The Swedish Energy Agency makes the assessment that the project handles an important challenge for the power grid and can contribute to a functioning system and increased understanding for the grid strength.