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This paper proposes firstly a Second Order Sliding Mode Control (SOSMC) based on a Super Twisting Algorithm (STA) (SOSMC-STA) combined with a Direct Field-Oriented Control (DFOC) strategy of a Five-Phase Induction Motor (FPIM). The SOSMC-STA is suggested for overcoming the shortcomings of the Proportional Integral Controller (PIC) and the Conventional Sliding Mode Controller (CSMC). Indeed, the main limitations of the PIC are the slower speed response, the tuning difficulty of its parameters, and the sensitivity to changes in system parameters, including variations in process dynamics, load changes, or changes in setpoint. It is also limited to linear systems. Regarding the CSMC technique, its limitation is the chattering phenomenon, characterized by the rapid switching of the control signal. This phenomenon includes high-frequency oscillations which induce wear and tear on mechanical systems, adversely affecting performance. Secondly, this paper also proposes a Loss Model Controller (LMC) for FPIM energy optimization. Thus, the suggested LMC chooses the optimal flux magnitude required by the FPIM for each applied load torque, which consequently reduces the losses and the FPIM efficiency. The performance of the optimized DFOC-SOSMC-STA based on the LMC is verified using numerical simulation under the Matlab environment. The analysis of the simulation results shows that the DFOC-SOSMC-STA guarantees a high dynamic response, chattering reduction, good precision, and robustness in case of external load or parameter disturbances. Moreover, the DFOC-SOSMC-STA, combined with the LMC, reduces losses and increases efficiency. [ABSTRACT FROM AUTHOR]

In this article, a novel sliding mode adaptation mechanism of a model reference adaptive system speed estimator and a modified sliding mode speed controller are proposed to replace the proportional-integral controller used in the adaptation mechanism of the model reference adaptive system and the proportional-integral speed controller, respectively. The suggested control strategy is designed by sensorless direct torque control with space vector modulation based on a sliding mode speed controller and a model reference adaptive system sliding mode speed estimator. The contribution of this work is the development of one control law based on a modified nonlinear component to overcome the first-order sliding mode control limitations, such as the chattering phenomenon. The performance of the suggested controller-based direct torque control with space vector modulation is verified by digital simulation with different operation conditions, like the abrupt variations in the load torque and the reference speed, using the MATLAB/SIMULINK environment. In fact, such simulation results are experimentally checked utilizing a dSPACE-1104. [ABSTRACT FROM AUTHOR]

Summary: This article is interested in a controlled three‐phased voltage source inverter (VSI) for a grid‐connected wind power generator. The objective consists of participating in auxiliary services by enhancing the grid stability. An active wind generator associated with a battery/super‐capacitor storage system composes the studied renewable generator. It is related to a power consumer (load) to form a microgrid (MG) that can work according to grid stability in two modes: standalone and grid‐tied. Thus, the principal objective of this study is to develop a robust control method for MG connection with the grid to ensure the grid voltage and frequency regulation. This control has two control tasks: First, an adaptive droop control is implemented to adjust power flows exchanged with the grid to ensure its stability. It regulates its voltage and frequency. Second, a sliding mode control (SMC) with super‐twisting algorithm is put forward for the VSI to improve the regulation of the grid voltage and frequency under uncertainties. It improves control results concerning the reduction of harmonics caused by sudden variations of the load and of powers exchanged with the grid. It allows preventing the phenomenon of chattering created by classical sliding mode technique. Extensive simulation studies are carried out under MATLAB/Simulink. They prove the effectiveness of the suggested droop and SMCs compared with the classical proportional‐integral controller. [ABSTRACT FROM AUTHOR]

A field-programmable gate array- (FPGA-) based nonlinear Direct Torque Control (DTC) associated with Space Vector Modulation (SVM), Input-Output Feedback Linearization (IOFL), and second-order super-twisting speed controller is proposed to control an induction motor drive. First, the nonlinear IOFL is proposed to achieve a decoupled flux and torque control and the SVM technique is used to control the inverter switching frequency which reduces the torque ripples and noise. Next, to enhance the speed regulation, a super-twisting speed controller is added to an SVM-DTC-IOFL scheme. The nonlinear SVM-DTC-IOFL ensures a high dynamic response, good robustness under the external load disturbances. The Lyapunov theory is used to analyze the system stability. Then, this paper presents the interest of implementing the suggested SVM-DTC-IOFL using a Field-Programmable Gate Array (FPGA) circuit. The main interest of the FPGA-implementation is the reduction of the control loop delay, which is evaluated to a few microseconds, thanks to the parallel processing offered by the FPGA. The performances of the proposed control algorithm are investigated by digital simulation using the Xilinx system generator tool and an experimental implementation utilizing an FPGA-Virtex-5-ML507. [ABSTRACT FROM AUTHOR]

This paper deals with the design and Hardware In Loop (HIL) verification of a novel intelligent Super-twisting Sliding Mode Speed Controller (STSMSC) based on a Sugeno-Takagi Fuzzy Logic System (STFLS) for an induction motor controlled by an improved Modified Direct Torque Control (MDTC) approach. Indeed, Conventional Super-twisting Sliding Mode Speed Controller (CSTSMSC) is chosen as an alternative solution for attenuating the chattering phenomenon brought on by the discontinuous control law of the First Order Sliding Mode Speed Control (FOSMSC) and maintaining its advantages like simplicity, robustness and accuracy. Moreover, the STSMSC is a type of a second order sliding mode control technique that needs only the information about the sliding surface, not its time derivative. However, the choice parameters of the CSTSMSC existing in the control law effects the tracking accuracy, the overshoot and the amplitude of the chattering. Therefore, an STSMSC based on an STFLS (STFLS-STSMSC) is proposed for online tuning of these parameters in transient and steady state operations. In fact, the STFLS is considered as an intelligent supervisor to adjust these parameter values according to the system state, which consequently provides excellent performance consisting in a higher robustness rate under disturbances and uncertainties, tracking with excellent accuracy and reduced chattering in steady state and transient operations. Numerous simulation and HIL co-simulation results are presented to demonstrate the effectiveness of the suggested STFLS-STSMSC based MDTC implemented on a Xilinx FPGA Zynq 7000 SoC ZC702. [ABSTRACT FROM AUTHOR]

The conventional direct torque control (DTC), based on the hysteresis controllers and the switching table, operates with a variable switching frequency, which decreases the conventional DTC performances, like the torque and flux ripples. Thus, the space vector modulation (SVM), used in the DTC, ensures a constant switching frequency and improves the DTC performances. The first aim of this paper is to present a comparison study between the DTC with an SVM (DTC-SVM) based on the Proportional Integral regulators (DTC-SVM-PI) and the DTC-SVM based on the sliding mode controllers (DTC-SVM-SMC). These two approaches are complex control algorithms which require faster micro-controllers; therefore the second objective of this paper is to present the implementation of the DTC-SVM-PI and the DTC-SVM-SMC on the Field Programmable Gate Array (FPGA), due to the parallel processing capability of the FPGAs. The two approaches are designed and simulated using the Xilinx System Generator (XSG) and implemented using an FPGA Virtex 5. The simulation results in the transient behavior and the steady state of the induction motor controlled by these two approaches are compared and discussed. The hardware FPGA implementation results show the effectiveness of the FPGA relative to the digital signal processor in terms of execution time. [ABSTRACT FROM AUTHOR]