This article proposes an event-triggered sliding mode control (ETSMC)-based fault ride-through (FRT) scheme for doubly fed inductor generator (DFIG)-based wind energy systems. The design aims at mitigating dynamic instabilities resulting from grid faults by properly regulating the dc-link voltage with support from a supplemental energy storage (super-capacitor). The high-density power support from the super-capacitor is efficiently facilitated by the dual active bridge converter (DABC) because of its high voltage conversion ratio and very low core loss. The event-triggered SMC approach allows updating the control input only when certain stability conditions are violated, thus reducing the computational burden and mitigating the chattering effect typically presents in the standard SMC. The ETSMC is augmented by a disturbance observer to achieve robustness against mismatched disturbances and parameter fluctuations. The design is validated using a DFIG-based wind energy system connected t
This paper proposes a novel fault ride-through (FRT) scheme for doubly fed inductor generator (DFIG)-based wind turbines. The approach combines an event-triggered sliding mode control (ETSMC) with a super-capacitor and a high-frequency magnetic linked dual active bridge converter (DABC). The design aims to mitigate grid fault induced transient instability by properly regulating the dc-link voltage to near its pre-fault level. The event-based SMC approach allows updating the control input only when certain stability conditions are violated, thus reducing the computational burden and mitigating the chattering effect typically present in standard SMC. The design is validated using a DFIG-based wind energy system connected to a feeder of a microgrid network. The obtained results confirm the performance and capability of the proposed scheme in providing necessary FRT support by effectively regulating the dc-link voltage and reducing converter loading during grid faults.
This paper proposes a control scheme based on event triggered sliding mode control (ETSMC) to improve the network stability of WECS-based microgrids during bus voltage excursions. The ETSMC scheme is designed to effectively regulate the bus voltage near its rated value with the reactive current support from a static synchronous compensator (STATCOM) such that the overall network stability of the microgrid remains unhampered. Reliance on an event triggered approach enables the control input to be updated only when certain pre-established conditions (triggering instants) are violated. Thus, the communication channel is only utilized during these instances and remains free otherwise. Thus, resulting in reduced communication channel bandwidth and computational power as well as significant reduction in the chattering phenomena that is typically associated with SMC. The proposed approach was validated using a WECS-based test microgrid subject to network instabilities and mismatched uncertain
This paper proposes an event-triggered sliding mode control (SMC)-based fault ride through (FRT) strategy for doubly-fed-induction-generator (DFIG)-based wind turbines. An event-triggered SMC (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 event-triggered SMC is only updated when certain conditions are violated, the proposed approach results in reduced computational burden and channel bandwidth. Additionally, it reduces the chattering phenomena typically associated with 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 paper utilizes high frequency isolation transformer, which dramatically reduces the costs associated with the re