Fault ride-through capability enhancement of DFIG-based wind turbine using novel dynamic voltage restorer based on two switches boost converter coupled with quinary multi-level inverter

Abstract

Doubly fed induction generator (DFIG)-based wind turbine includes several prominent advantages. Despite that, due to its sensitive nature to the network disturbances, it cannot follow the normal and safe operation in disturbance duration. Fault ride-through (FRT) capability is recognized as an important requirement inflicted on grid codes to confirm the stable and safe operation of DFIG. Dynamic voltage restorer (DVR) has relatively compensated the disturbed voltage so that DFIG can follow its normal and safe operation in the power system. In this paper, a novel two switches boost converter (TSBC) coupled with quinary multi-level inverter (QMLI) is proposed as AC voltage synthesizer part of DVR to enhance its performance in order to compensate the different voltage disturbances and enhance DFIG’s FRT capability. Low current ripple and low stress switches are two outstanding advantages of the suggested step-up DC/DC converter which provide the required DC voltage for QMLI. Meanwhile, QMLI provides a high level staircase sinusoidal voltage with consideration of the low number of switches. Some plausible disturbances are considered to affect the power system so that the performance of suggested DVR-based TSBC-QMLI to be verified and validated. Eventually, the simulation results show DVR-based TSBC-QMLI has accurately compensated the balanced and unbalanced voltage sag, swell, flicker and harmonic.