Performance comparison of standalone SCIG and PMSG-based wind energy conversion systems

Off-Grid small wind turbines provide a very attractive renewable energy source for remote communities and small businesses. Due to its high reliability and efficiency, gearless-drive permanent magnet synchronous generator might currently be the most common wind turbine in such application. However, wind turbines using geared- squirrel cage induction generator are still widely accepted due to robustness, simplicity, light weight and low cost. This work develops variable-speed wind energy conversion systems using squirrel cage induction generator and permanent magnet synchronous generator. Both generators are connected to the load through a switch-mode rectifier and an inverter. The performances of both generators are examined under comparable power ratings and similar control techniques. A comparison between the two generators is presented for generator´s fault characteristics, generator´s efficiency under maximum power point tracking control, generator´s current harmonic distortion and generator´s behaviour under unbalanced load condition.