Abstract
This paper presents a co-simulation methodology for analyzing the dynamic interactions between modern wind turbines and the electrical power grid. By coupling a high-fidelity structural and aerodynamic simulation tool with average-value electrical representations, it is possible to capture complex wind turbine–grid behaviors that cannot be represented using conventional models. This is enabled and made more accessible through the utilization of the Functional Mock-up Interface (FMI). This standardized interface provides access to state-of-the-art open-source libraries and software developed by the community, incorporating advanced control logic without additional implementation effort. In particular, the wind turbine controller includes the full complexity required for realistic operation, moving beyond overly simplified MPPT-based approaches.
The key contribution of this paper is a demonstration of the use of a Functional Mock-up Unit (FMU) that enables coupling between high-fidelity structural and aerodynamic modeling from OpenFAST and average-value models of the generator, DC-link, converter systems, and the grid. The grid is represented using the open-source RMS-based power system simulator TOPS. At the core of the electrical model is a direct-drive permanent magnet synchronous machine (PMSM), implemented with electric drive control schemes and fault-handling mechanisms. The framework supports two-way coupling between mechanical and electrical domains, enabling realistic simulation of electro-mechanical interactions across multiple time scales.
Key features of the combined methodology include DC-link voltage control, chopper-based overvoltage protection, and torque-limiting strategies for fault response. A grid-side converter model with PQ or PV control enables interactions with the dynamic power system. Preliminary case studies, including a curtailment event, illustrate the framework’s ability to capture coordinated transient behavior across subsystems. The proposed methodology provides a flexible and scalable approach for studying electro-mechanical interactions in converter-based wind turbines under diverse operating conditions, supporting detailed analysis of control strategies and fault responses within integrated simulation environments.
This work has been funded by the Research Council of Norway through the LowEmission (grant nr 296207) and NorthWind (grant nr 321954) centers, and by their respective industry partners.