Malek Ghanes

On Sensorless Induction Motor Drives: Sliding-Mode Observer and Output Feedback Controller

In this paper, a sensorless output feedback controller is designed in order to drive the induction motor (IM) without the use of flux and speed sensors. First, a new sliding-mode observer that uses only the measured stator currents is synthesized to estimate the speed, flux, and load torque. Second, a current-based field-oriented sliding-mode control is developed so as to steer the estimated speed and flux magnitude to the desired references. A stability analysis based on the Lyapunov theory is also presented in order to guarantee the closed-loop stability of the proposed observer-control system. Two experimental results for a 1.5-kW IM are presented and analyzed by taking into account the unobservability phenomena of the sensorless IM.

Experimental Validation of a Sampled-Data Passivity-Based Controller for Coordination of Converters in a Fuel Cell System

This paper deals with the control of a hybrid source combining a proton exchange membrane fuel cell and supercapacitors. To achieve this objective, an interconnection and damping assignment passivity-based control in a sampled-data context is implemented. This paper first details with this new controller and shows that it ensures the stabilization of the hybrid system at its desired equilibrium point under large range of sampling periods. These considerations are followed by a detailed discussion on experimental results achieved on a 1.2-kW test bench.

Industrial Application of a Second Order Sliding Mode Observer for Speed and Flux Estimation in Sensorless Induction Motor

In this chapter, a second order sliding mode observer for the induction motor (IM) without mechanical sensor is presented for the open problem of sensorless IM drives at very low frequency. This observer converges in finite time and is robust to the variation of parameters. To illustrate the proposed observer, firstly a very simple case is presented in order to exemplified the tuning parameters. Then, to highlight the technological interest of the proposed method and also show the difficulties due to real time computation constraints when a basic microprocessors are used, an industrial application is proposed.

Sliding mode control for uncertain input delay fractional order systems

A sliding mode control is developed for robust stabilization of fractional-order input-delay linear systems in presence of uncertainties and external disturbances. First, a fractional-order state predictor is used to compensate the delay in the input control. Second, a robust sliding mode control is proposed in order to stabilize the system and to thwart the effect of model uncertainties and external disturbances. The sliding mode controller is designed by considering a sliding surface defined by fractional order integral. Conditions for the existence and finite time reaching of the sliding mode in presence on bounded uncertainties and bounded external disturbances are established. Further, the stability of the closed loop system on the sliding mode is analyzed by using recent results on Lyapunov stability theory for fractional order systems. A numerical example is given to illustrate some theoretical results.