soft starter synchroniser (for a synchronous wind turbine generator

Accelerates the generator as a motor using the amortisseur windings, but reduces the stress on the grid connection in doing so.

Typically a wind turbine's blades are designed to slip off a lot of energy when standing still so as to not damage the windmill when shut down or in high winds. So it cannot create enough torque from a dead stop to accelerate it. The mill must be accelerated by using the generator as a motor, then once it gets to full speed, the wind torque takes over to keep it turning and then generating.

In a synchronous machine, the amortisseur winding is a separate winding of the stator that allows it to run as a squirrel cage motor, solely for the purpose of acceleration from a stop.