Power-Hardware Design and Topologies of Converter-Based Grid Emulators for Wind Turbines

Power-electronic-based grid emulators (GEs) emerge as a favorable method for testing grid-code compliances of wind turbines (WTs), thanks to their full controllability and improved efficiency. To accommodate the increasing power and voltage levels of WTs, scalability becomes a critical requirement for the topologies of converter-based GEs. This article identifies first the power rating of future GEs based on the system architecture and the evolution of WTs, followed by evaluating converter topologies of GEs for high scalability. Design considerations of power semiconductor devices, step-up transformers, dc chopper, and dc capacitors are also discussed for existing and prospective GEs.