Ruben Bufanio

This work presents the development and validation of a modular low-power wind turbine emulator (WTE) specifically designed for academic research and distributed generation applications. The primary objective is to provide a flexible and cost-effective test bench capable of replicating the aerodynamic and mechanical performance of a bladed rotor without the need for wind tunnels or specific field conditions. The emulator integrates a 4.5 kW three-phase induction machine as the motor and a 1 kW permanent magnet synchronous generator (PMSG). The system is managed by an ARM Cortex M7 microcontroller, which gives instructions to a Siemens Sinamics Variable Frequency Drive (VFD) that is used for torque vector control, offering superior dynamic response to wind speed variations. The aerodynamic characteristics were previously derived using blade element momentum (BEM) theory and validated using MATLAB/Simulink simulations. Unlike traditional steady-state emulators, this study addresses dynamic behavior through an autonomous control algorithm that reduces mechanical stress and compensates for inertia differences. Experimental tests conducted in a grid-connected scenario using a commercial on-grid inverter showed high correlation between the emulator’s output and the field data of a real EOLOCAL AG1000 turbine. The results confirm the system’s reliability as a platform for evaluating power conversion systems and for future expansions, such as blade pitch control emulation.

Small wind turbines (SWTs) have been a common option for rural electrification during recent decades. Recently, an application for connecting these devices to the grid was proposed. This requires an AC-coupled configuration, which brings the need for a power converter necessary for connection to the AC bus. This publication analyzes the requirements and commercial availability of such power converters, coming first to a conclusion on the lack of existing electronic power converters for SWTs, mainly in the lowest power range (<1 kW). As a result of this need, PV power converters were proposed, as they are both economically competitive and commercially available. The use of PV power converters for SWT AC-coupled applications is therefore analyzed as well, bringing a second conclusion: their use is possible but not straightforward, as some adaptations have to be taken into account. Finally, a suggested adaptation is proposed, in terms of hardware and software; the first field results of a prototype are presented, and they look very promising.