FPGA Implementation of a DTC-SVM Super-Twisting Sliding Mode Controller with Adaptive Stator Flux Observer for a Double Star Induction Motor

Fatma Zohra LATRECH, Asma BEN RHOUMA, Adel KHEDHER

Abstract

This paper presents the FPGA-based implementation of the Direct Torque Control method with Space Vector Modulation (DTC-SVM) for a Double Star Induction Motor (DSIM), enhanced by a Super-Twisting Sliding Mode Controller (STSMC) and an Adaptive Sliding Mode Stator Flux Observer (SMSFO). For improving the robustness of the control system, the conventional Proportional Integral (PI) controllers are replaced by the STSMC approach. A comparative study of the Classical DTC, of the DTC-SVM-PI and DTC-SVM-STSMC methods highlights the superior performance of the proposed approach with regard to a reduced chattering, an improved electromagnetic torque control, and an increased tolerance to system parameter variations. However, despite these improvements, the proposed system remains slightly sensitive to stator resistance variations. In order to overcome this, an adaptive SMSFO based on the Lyapunov stability theory is employed for an accurate flux and torque estimation under varying stator resistance conditions. The proposed control algorithm is developed by using a VHDL code for synthesis and deployment and implemented on a FPGA board through the Xilinx System Generator (XSG). The Hardware-in-the-Loop (HIL) tests carried out confirm the enhanced dynamic performance, robustness, and real-time applicability of the proposed strategy.

Keywords

DTC, DTC-SVM-PI, DTC-SVM-STSMC, DSIM, XSG, FPGA, Adaptive SMSFO.

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