Low Voltage Ride-Through of a Synchronous Reluctance Generator Based Variable Speed Wind Energy Conversion System

Grid codes want the wind energy conversion systems (WECS) to stay connected even when low voltage occurs at the point of common coupling (PCC) for a short-while. This paper is an attempt to propose a control strategy to achieve low voltage ride through (LVRT) for a variable speed grid-connected WECS based on Synchronous reluctance machine (SyRM) as a generator. The SyRM is controlled by field oriented control technique and grid-side-converter is controlled by grid voltage oriented control. Hill climbing algorithm is used to implement maximum power point tracking in the WECS. The LVRT capability of the system under three-phase grid fault condition is achieved using three different control techniques namely, modulation index control, de-loading and crowbar protection. These methods have been simulated in Simulink/MATLAB environment and the results obtained show that these techniques work very effectively for realizing LVRT in a SyRM based WECS.