Enhancing DFIG Wind Turbine during Three Phase Fault Using Parallel Interleaved Converters and Dynamic Resistor

Abstract

This paper investigates the fault ride through (FRT) capability improvement of a doubly fed induction
generator (DFIG)-based wind turbine using a dynamic voltage restorer (DVR). Series compensation of terminal voltage
during fault conditions using DVR is carried out by injecting voltage at the point of common coupling to the grid voltage
to maintain constant DFIG stator voltage. However, the control of the DVR is crucial in order to improve the FRT
capability in the DFIG-based wind turbines. The combined feed-forward and feedback (CFFFB)-based voltage control of
the DVR verifies good transient and steady- state responses. The improvement in performance of the DVR using CFFFB
control compared with the conventional feed-forward control is observed in terms of voltage sag mitigation capability,
active and reactive power support without tripping, dc-link voltage balancing, and fault current control. The advantage of
utilizing this combined control is verified through MATLAB/Simulink-based simulation results using a 1.5-MW grid
connected DFIG-based wind turbine. The results show good transient and steady-state response and good reactive power
support during both balanced and unbalanced fault conditions.