Control of a permanent-magnet synchronous generator wind turbine system during grid fault

Abstract

In this research, an enhanced control scheme for the permanent-magnet synchronous generator (PMSG) vvind turbincs under grid voltage fault condition is introduced. The machine-side converter (MSC) Controls the DC-link voltage; however, this voltage value can be still increased during the grid fault. Thus, the braking chopper (BC) added to the DC-bus will be activated to dissipate the surplur powcr between the grid and generator powers. Meanwhile, the grid active power is regulated at the grid-side converter (GSC), from which can be exploited to inject reactive current into the grid for assisting the grid voltage recovery. Also, an algorithm of positive-sequence current control in the dq-axis is implemented, based on feedback linearization theory. The validity of this control algorithm has been verified by the simulation of the 2MW-PMSG wind turbine System.