Amor Khlaief

A Nonlinear Observer for High-Performance Sensorless Speed Control of IPMSM Drive

This paper aims to provide a high-performance sensorless control of interior permanent magnet synchronous motor (IPMSM) based on nonlinear position and speed observer. The proposed nonlinear observer is constructed using the flux linkage as new state variable without speed dependence. The nonlinear observer gives estimation of the rotor position using a trigonometric function and the speed estimation is obtained from estimated position using proportional-integral (PI) tracking controller. This observer is stable easy to implement and does not require a large computing time. At standstill, we used the voltage pulses method to detect the initial rotor position. Short voltage pulses are applied to the stator winding and the initial rotor position is estimated from the measured peak current. High-dynamic performance is obtained using the vector field-oriented control and the space vector pulsewidth modulation techniques. Experimental results with 1.1-kW IPMSM have validated the effectiveness of the proposed sensorless speed control using nonlinear observer. The experimental implementation is carried out on powerful dSpace DS1103 controller board based on the DSP TMS320F240.

Performance analysis of FOC and DTC for PMSM drives using SVPWM technique

The aim of this article is to present the performance of field oriented control (FOC) and direct torque control (DTC) of a permanent magnet synchronous motor (PMSM) using the technique of space vector pulse width modulation (SVPWM). First, after developing a mathematical model of PMSM we present the principle of space vector modulation technique to use in commands. Secondly, we developed a field oriented control and direct torque control strategy. Finally, we proposed a failover system between direct torque control and field oriented control in the event of default or loss of information.

A sliding-mode observer for high-performance sensorless control of PMSM with initial rotor position detection

ABSTRACTThis paper proposes a new method to detect the initial rotor position at standstill of permanent magnet synchronous motor (PMSM). To estimate rotor position and rotor speed from the back electromotive force (EMF) voltage, we apply sensorless speed control based on sliding-mode observer (SMO). The initial rotor position is detected by using a suitable high-frequency sequence of voltage pulses intermittently applied to the stator windings at standstill. With this approach, we managed to minimise the error on the estimated position to 3.75° electrical degrees without additional materials and uncomplicated calculations. The stability of the proposed SMO was verified using the Lyapunov method. Numerical simulations and experiments demonstrate that the novel SMO method can effectively estimate rotor position and speed with achievement of good static and dynamic performance. The experimental implementation is carried out on powerful dSpace DS1103 controller board based on the digital signal processor (DS...

Implementation of stator resistanceadaptation for sensorless speed control of IPMSM drive based on nonlinear position observer

This paper deals with a new method of on-line stator resistance identification based on model reference adaptive systems (MRAS) technique for high performance sensorless speed control of interior permanent magnet synchronous motor (IPMSM) drive. In order to estimate the rotor position, a nonlinear position observer algorithm based on the IPMSM fluxes is proposed. The nonlinear observer is constructed using the flux linkage as a new state variable without speed dependence. The nonlinear observer estimated the rotor position by using a trigonometric function. The reference and adjustable models, developed in the d-q synchronous reference frame, are used in the MRAS scheme to estimate the stator resistance from measured terminal voltages and currents. Finally, experimental results validate the correctness and effectiveness of the proposed sensorless speed vector control. The experimental implementation is carried out on powerful dSpace DS1103 controller board.

Position sensorless vector control of PMSM drives based on SMO

In this document, an sensorless field oriented control (FOC) for PMSM utilizing the SMO is proposed. We have building a new sliding mode observer to estimate the rotor velocity/position from the back EMF, in which a continuous function (called sigmoid) is applied instead the sign method. The stability verification of our observer was made by the Lyapunov theorem. The effectiveness of sensorless FOC was validated by the results obtained in section 4. The simulation results obtained by using Matlab/Simulink program validate the robustness of the SMO under parameter variations and external disturbance.

Fault tolerant control and reconfiguration for three-phase permanent magnet synchronous motors drive

this paper proposes a fault tolerant control (FTC) for permanent magnet synchronous motors (PMSM) using field-oriented control (FOC) and direct torque control (DTC) strategy. In order to ensure continuity of operation and without losing PMSM performance in fault, the proposed FTC allows transition from FOC to DTC. The FOC of PMSM drive needed a mechanical sensor to measure rotor position but with the second strategy this was not necessary. The simulation results confirm the effectiveness of the FTC method proposed.

A rotor initial position estimation method for sensorless field-oriented control of permanent magnet synchronous motor

In this paper, a new technique to improve initial rotor position detection at standstill of a permanent magnet synchronous motor (PMSM) is presented. Sensorless field-oriented control (FOC) of a PMSM at low speed remains a difficult task. In order to estimate the position and rotor speed, we proposed a novel structure of a full-order sliding mode observer (FO-SMO) in a sensorless FOC. At standstill, we used a voltage pulse sequence applied to the windings in order to detect the initial rotor position. With this technique, we managed to minimize the error on the estimated rotor position to 3.75° (electrical) compared with others. The validity of the proposed approach with a 1.1-kW low-speed PMSM sensorless FOC has been proved by experimental results.

Performance analysis of PMSM DTC drives under inverter fault

This paper presents an investigation of an inverter fault tolerant direct torque control (DTC) of permanent magnet synchronous motor (PMSM) with loss of one leg. In case of faulty inverter, continuous operation is necessary and thus a breakdown of the PMSM drive is unacceptable. The basic idea of this work consists in analyzing performance of a three legs inverter and two legs inverter fed PMSM drive using DTC technique. Simulation results show that the two legs inverter fed PMSM is able to operate steadily under the DTC approach proposed.

Sensorless FOC of PMSM drives based on full order SMO

This document deals with a sensorless field oriented control (FOC) for permanent magnet synchronous motor (PMSM) drives by using a full order sliding mode observer (FOSMO). We have constructed a FO-SMO to estimate the position and velocity. The Lyapunov theorem is used to verify the FO-SMO stability. The experimental findings indicate the robustness of SM observer under parametric variations.