Direct Torque Control of Saturated Doubly-Fed Induction Generator using High Order Sliding Mode Controllers

Abstract

Abstract-The present work examines a direct torque control strategy using a high order sliding mode controllers of a doublyfed induction generator (DFIG) incorporated in a wind energy conversion system and working in saturated state. This research is carried out to reach two main objectives. Firstly, in order to introduce some accuracy for the calculation of DFIG performances, an accurate model considering magnetic saturation effect is developed. The second objective is to achieve a robust control of DFIG based wind turbine. For this purpose, a Direct Torque Control (DTC) combined with a High Order Sliding Mode Control (HOSMC) is applied to the DFIG rotor side converter. Conventionally, the direct torque control having hysteresis comparators possesses major flux and torque ripples at steady-state and moreover the switching frequency varies on a large range. The new DTC method gives a perfect decoupling between the flux and the torque. It also reduces ripples in these grandeurs. Finally, simulated results show, accurate dynamic performances, faster transient responses and more robust control are achieved.

Improved Rotor Flux and Torque Control Based on the Third-Order Sliding Mode Scheme Applied to the Asynchronous Generator for the Single-Rotor Wind Turbine

“…In order to improve the performance of the classical DFTC strategy, the standard hysteresis comparators were replaced by two TOSMC controllers and the switching table by the traditional SVM strategy. The electromagnetic torque and rotor flux estimation block keep the same shape as that established for traditional DFTC with PI controllers, as described in [66,67]. In this proposed DFTC control strategy, the electromagnetic torque and rotor flux are regulated by two proposed TOSMC controllers, while the SVM technique replaces the switching table.…”