Experimental implementation of Super-Twisting Based High Order Sliding Mode Control for MCT driven DFIG-DC energy conversion system

Abstract

This paper develops a High Order Sliding Mode Control for energy conversion system DC-link based on DFIG. In the studied system, a bridge rectifier ensures the connection between the stator windings and the DC bus, while a PWM power converter is placed between the DC bus and the rotor windings. The proposed topology presents the most appropriate solution which allows to connect marine renewable energy farms to the High Voltage Direct Current transmission systems. Unfortunately, the major drawback of the energy conversion system DC-link based on DFIG is the highly distorted stator voltage due to the bridge rectifier on stator side. So, in order to regulate the DC voltage and the stator frequency with harmonic current suppression, this paper includes the development of super-twisting sliding mode algorithm for a stand-alone DFIG-DC system which is used in a tidal stream turbine. Indeed, to improve the quality of stator currents, reference rotor harmonic currents are calculated and injected with the fundamental d and q-axis reference rotor currents. Finally, the performances of the DFIG-DC energy conversion system are shown through digital simulation and experimental results. These results give high dynamic performances of the DC voltage regulation and the reduction capability of the harmonics.