Equivalent circuit for the dynamic analysis of a PM synchronous generator/back-to-back converter drive for VAWT applications

The paper presents an equivalent circuit summing up both the dynamics of the drive kinematic train and the quasi-steady state electric behaviour of a wind generation drive based on a vertical axis wind turbine gearlessly coupled to a permanent magnet synchronous generator, interfaced to the main grid by a back-to-back converter. By the implementation of this circuit in the Simulink® environment, it is possible to analyze both the steady-state operation and the mechanical transients due the wind turbulence. In particular, a sensorless configuration for the maximum power point tracking is considered. In the example of application, the influence of different control architectures and converter structures on the system performance (i.e, effectiveness of the angular speed control, rms armature current, energy yield) is investigated.