PROJECT TITLE :

Scaled Current Tracking Control for Doubly Fed Induction Generator to Ride-Through Serious Grid Faults

ABSTRACT:

For doubly fed induction generator (DFIG)-based wind turbine, the most constraint to ride-through serious grid faults is that the limited converter rating. So as to understand controllable low voltage ride through (LVRT) underneath the everyday converter rating, transient control reference typically would like to be modified to adapt to the constraint of converter's most output voltage. Usually, the generation of such reference relies on observation of stator flux and even sequence separation. This can be vulnerable to observation errors during the fault transient; moreover, it will increase the complexity of management system. For this issue, this paper proposes a scaled current tracking management for rotor-aspect converter (RSC) to boost its LVRT capability without flux observation. In this technique, rotor current is controlled to track stator current in a bound scale. Below correct tracking coefficient, each the specified rotor current and rotor voltage can be constrained inside the permissible ranges of RSC, thus it will maintain DFIG under control to suppress overcurrent and overvoltage. Moreover, throughout fault transient, electromagnetic torque oscillations will be greatly suppressed. Based on it, sure further positive-sequence item is injected into rotor current reference to produce dynamic reactive support. Simulation and experimental results demonstrate the feasibility of the proposed technique.