A series reactor based converter protection scheme of doubly fed induction generator for low voltage ride through

This paper proposes a new converter protection method, primarily based on a series reactor which avoids the doubly-fed induction generator being disabled by crowbar protection during fault conditions. The series reactor shows high impedance under “fault frequency” and low impedance under “normal frequency”, which makes it limit fault current effectively. A combined robust demagnetization control scheme which doesn´t rely on system parameter is also discussed here. The analysis indicates that the induced series reactor also accelerates the damping of dc stator flux. In order to validate the proposed strategy, simulations have been carried out, and the result shows that the proposed system could survive grid fault without crowbar.