Event-Triggered SMC-Based FRT Approach for DFIG-Based Wind Turbines Equipped With DVR With High-Frequency Isolation

This article proposes an event-triggered sliding mode control (ETSMC)-based fault ride-through (FRT) strategy for doubly-fed-induction-generator (DFIG)-based wind turbines. An ETSMC approach is designed for a dynamic voltage restorer (DVR) with a high-frequency isolated dc-dc converter. The aim is to regulate the stator terminal voltage by injecting appropriate voltage to regulate it near the reference point. Since the control signal in the ETSMC is only updated when certain conditions are violated, the proposed approach results in reduced computational burden and channel bandwidth. In addition, it reduces the chattering phenomena typically associated with sliding mode control (SMC) and reduces harmonic distortion. The ETSMC is augmented by a disturbance observer to further improve its robustness against mismatched uncertainties. The DVR topology considered in this article utilizes a high-frequency isolation transformer, which dramatically reduces the costs associated with the regular isolation transformer. The proposed FRT strategy is validated with a DFIG-based wind turbine connected to a test microgrid. The obtained results confirmed the effectiveness of the proposed approach in mitigating dynamic instabilities resulting from grid faults while minimizing the usage of the communication channel.

Automated summary

This article proposes an event-triggered sliding mode control (ETSMC)-based fault ride-through (FRT) strategy for doubly-fed-induction-generator (DFIG)-based wind turbines. The aim is to regulate the stator terminal voltage by injecting appropriate voltage to regulate it near the reference point. The proposed approach reduces computational burden, chattering phenomena, harmonic distortion, and utilizes a cost-effective DVR topology with a high-frequency isolation transformer. The effectiveness of the proposed approach is validated with a DFIG-based wind turbine connected to a test microgrid.