An Integral Sliding Mode Stator Current Control for Industrial Induction Motor

An integral sliding mode control (ISMC) for stator currents of the induction motor (IM) is developed in this work. The proposed controller is developed in the d-q synchronous reference frame, by using the indirect field-oriented control (FOC) method. Robust asymptotic tracking of stator current components in the presence of model uncertainties and current coupling disturbance terms has been guaranteed by using an enhanced ISMC surface. More precisely, the stationary error of stator currents has been eliminated, and the accuracy of the regulators has been enhanced. According to the Lyapunov approach, it has been proven that the stator currents tracking happens asymptotically, and consequently, the stability of each loop has been demonstrated. Simulation and experimental results show the capability of the new controller in diminishing system chattering and increasing the robustness of the designed scheme, considering the variation of the plant parameters and current disturbance terms. It has been illustrated that compared with the conventional ISMC and PI regulators, the proposed current controllers provide smoother control actions and excellent dynamics. In addition, because of the precise control over the rotor flux, the rotor flux weakening method is employed to run the motor at a higher speed than the rated value.The University of the Basque Country (UPV/EHU) [grant number PIF 18/127] has funded the research in this paper

An improved predictive current control for IM drives

In Finite Control Set-Model Predictive Control (FCS-MPC), the model of the induction machine (IM) is expressed in the a b or d q reference frame, and then the back-EMF is estimated based on the applied voltage vectors. In this work, the d-q reference frame is used but unlike the existing method, the esti- mated back-EMF is calculated by filtering the voltage vectors. Moreover, the work studies the importance of the discretization method on the predictive control behavior of IM. It has been demonstrated that the mentioned enhancements lead to an efficient Total Harmonic Distortion value for stator current (THD i) and torque ripple reduction compared to the conventional methods. The proposed Predictive Current Controller (PCC) has been validated experimentally by using a commercial IM of 7:5½kW controlled by a dSpace 1103 real-time control board running with sample frequencies from 10½kHz to 80½kHz . The test results validate the developed controller’s ability to meet the control objectives in a whole range of speeds, loads, and sampling frequencies.The authors wish to express their gratitude to the Gipuzkoako Foru Aldundia through the project Etorkizuna Eraikiz 2022–2023, the Basque Government through the project EKOHEGAZ (ELKARTEK KK-2021/00092), the Diputacion Foral de Alava (DFA) through the project CONAVANTER, and to the UPV/EHU through the project GIU20/063 for supporting this work

An Enhanced Sliding Mode Speed Control for Induction Motor Drives

In this paper, an enhanced Integral Sliding Mode Control (ISMC) for mechanical speed of an Induction Motor (IM) is presented and experimentally validated. The design of the proposed controller has been done in the d-q synchronous reference frame and indirect Field Oriented Control (FOC). Global asymptotic speed tracking in the presence of model uncertainties and load torque variations has been guaranteed by using an enhanced ISMC surface. Moreover, this controller provides a faster speed convergence rate compared to the conventional ISMC and the Proportional Integral methods, and it eliminates the steady-state error. Furthermore, the chattering phenomenon is reduced by using a switching sigmoid function. The stability of the proposed controller under parameter uncertainties and load disturbances has been provided by using the Lyapunov stability theory. Finally, the performance of this control method is verified through numerical simulations and experimental tests, getting fast dynamics and good robustness for IM drives.The University of the Basque Country (UPV/EHU) [grant number PIF 18/127] has funded the research in this pape

Generalized Predictive Control Scheme for a Wind Turbine System

In this paper, a generalized predictive control scheme for wind energy conversion systems that consists of a wind turbine and a doubly-fed induction generator is proposed. The design is created by using the maximum power point tracking theory to maximize the extracted wind power, even when the turbine is uncertain or the wind speed varies abruptly. The suggested controller guarantees compliance with current constraints by applying them in the regulator’s conceptual design process to assure that the rotor windings are not damaged due to the over-current. This GPC speed control solves the optimization problem based on the truncated Newton minimization method. Finally, simulation results, which are obtained through the Matlab/Simulink software, show the effectiveness of the proposed speed regulator compared to the widely used Proportional-integral controller for DFIG.The University of the Basque Country (UPV/EHU) (grant number PIF 18/127) has funded the research in this paper

Modelling and advanced control design of three-phase electrical machines.

185 p.The main objective of this thesis is to control the electrical three-phase AC machines, using advanced control methods to meet the performance requirements for the plant model. Throughout this thesis, four different electrical three-phase AC machines were employed as motors or generators: the Squirrel Cage Induction Machine (SCIM), Doubly Fed Induction Machine (DFIM), Permanent Magnet Synchronous Machine (PMSM), and Permanent Magnet Vernier Machine (PMVM). When these machines are working as motors or generators, their shaft is mechanically connected to a load. In the generator regimen, two different turbine types were considered: the Wells turbine in Oscillating Water Column (OWC) and Wind Turbine System (WTS).In this thesis, different control techniques are proposed to govern different aspects of the machine. The Integral Sliding Mode Control (ISMC) and Finite Control Set-Model Predictive Control (FCS-MPC) are employed for the current regulation of electrical machines. For velocity regulation, various methods such as the ISMC method, Generalized Predictive Control (GPC) technique, and a GPC-based Proportional Integral (PI) approach were proposed. Three different GPC schemes were implemented: nonlinear, analytical, and industrial, each offering different features