Experimental Comparison of Performances of Grid Connected Small Wind Energy Conversion Systems

This paper presents an experimental comparative study of performances in terms of efficiency on two possible grid connected small wind turbine systems. One of the systems is based on Permanent Magnet Generator (PMG) and the other system is based on Wound Rotor Induction Generator (WRIG). The Power Conditioning System (PCS) for grid connection of the PMG-based system requires a rectifier, boost converter and a grid-tie inverter, while the WRIG-based system employs a rectifier, a switch and an external resistance in the rotor side with the stator directly connected to the grid. Experimental test benches for both systems are implemented using Wind Turbine Emulator (WTE) and Maximum Power Point Tracking (MPPT) control strategy. The procedure for calculate the PCS losses, energy capture and energy loss is presented. The expected efficiency of the systems is investigated for wind distributions at eight sites in Newfoundland and Labrador. It is shown that a WRIG-based system could provide 5% higher efficiency in contrast to a PMG-based system and could be an optimum alternative in the small wind energy domain.