Promoted supercapacitor control scheme based on robust fractional-order super-twisting sliding mode control for dynamic voltage restorer to enhance FRT and PQ capabilities of DFIG-based wind turbine

• DOI: 10.1016/j.est.2021.102983
• Publication Date: 2021-08-13T14:23:40Z
• Authors: Ali Darvish Falehi; Hossein Torkaman
• Keywords: Robustness

Abstract Aside from the importance of power quality issue, fault ride-through capability is also of greater importance which must be required for doubly-fed induction generator to meet the grid code requirements. Both of these issues can be relatively enhanced using a series-connected power electronic-based compensator styled dynamic voltage restorer. This compensator can present the best compensation performance in case that both the power supply and multilevel inverter parts to be upgraded. In this regard, this paper aims to suggest two novelties: 1) New asymmetrical mutual E-type clamped X-type multilevel inverter to provide high-step staircase sinusoidal voltage containing low number of switches 2) New robust fractional-order super-twisting sliding mode control for supercapacitor-based power supply to provide steady and smooth DC voltage As for the creative structure of the proposed inverter, special geometric progression of DC voltage source and low switch count, high-step staircase sinusoidal voltage can be provided. It has been compared with the traditional and recently proposed inverters to validate its step-creation capability. As for the chattering free scheme of the proposed controller, increase of the system freedom degree and robustness against the uncertainties, nonlinearities and perturbations, steady and smooth DC voltage can be provided. It has been compared with PID, SMC and FLC controllers to validate its tracking capability. Both these suggestions have effectively enhanced the AC voltage synthesizer of DVR to accurately and promptly enhance both the FRT and PQ capabilities of DFIG-based wind turbine. The compensation capability of the proposed DVR has been evaluated under different voltage disturbances, and also compared with the conventional DVR and improved series resistive limiter along with superconducting based DC-chopper circuit. Finally, all the disturbance conditions have been perfectly compensated with trivial THD by proposed DVR, and also the DFIG-based wind turbine has been well stabilized.