Evaluation of the Small-Scale Wind Turbine Converter’s Efficiency Built with Various Types of Semiconducting Devices

Abstract

Research in the field of power semiconductors led to creation of the commercially available wide bandgap switching devices, like Silicon Carbide based MOSFETs and Gallium-Nitride based HEMTs. The high switching frequencies with moderate losses, reduced conduction losses and excellent parasitic parameters with respect to comparable Silicon based devices allow using of them in efficiency sensitive systems. Utilization of the wide bandgap devices for renewable energy generation, as in case for small-scale wind turbines, provide valuable changes not only in the annual energy, but also in overall regulation parameters, thermal stress and, as a result, reliability of the system. This paper presents the comparative evaluation of the small-scale wind turbine performance using 650V Si MOSFETs, Si IGBTs, SiC MOSFETs and GaN HEMTs as switching devices. The chosen topology is based on the standard 2-level converter, consisting out of 3 phase half-bridges. The converter, designed for the actual load of 3 kW PMSM based wind generator is controlled by Direct Torque Control (DTC) principles. The influence of the torque and flux regulators settings, as well as wind speed distribution, is drawn in plots, based on efficiency surfaces and relative year efficiency graphs, repeated for each device. Relating to the simulation results, a comparative analysis is performed and conclusions about using of wide bandgap devices in the small scale windmill systems are drawn.