Power quality analysis and system simulation on permanent magnet direct-drive wind turbine

Variable speed wind turbines yield more energy than the fixed speed wind turbines, reduce power fluctuations and improve reactive power supply. The power quality of permanent magnet wind turbine with a direct-drive generator (PMWT) has been analyzed in this paper. A simulation model of variable speed wind turbine was developed with the simulation tool of PSCAD/EMTDC. Component models and equations are addressed and their implementations in PSCAD/EMTDC are described. According to IEC61400-21, the effect of power fluctuations is quantified by measured active power, harmonics, and short term flicker severity of wind turbine. Emphasis is placed on the voltage flicker severity at various wind speed of PMWT, compared with fixed speed wind turbine. Simulation studies provide control performance and dynamic behavior of a direct-drive PMWT under varying wind speeds for power quality analysis.