Mohamed Boussak

Implementation and experimental investigation of sensorless speed control with initial rotor position estimation for interior permanent magnet synchronous motor drive

In this paper, a new approach to sensorless speed control and initial rotor position estimation for interior permanent magnet synchronous motor (IPMSM) drive is presented. In rotating condition, speed and rotor position estimation of IPMSM drive are obtained through an extended Kalman filter (EKF) algorithm simply by measurement of the stator line voltages and currents. The main difficulty in developing an EKF for IPMSM is the complexity of the dynamic model expressed in the stationary coordinate system. This model is more complex than that of the surface PMSM, because of the asymmetry of the magnetic circuit. The starting procedure is a problem under sensorless drives, because no information is available before starting. The initial rotor position is estimated by a suitable sequence of voltage pulses intermittently applied to the stator windings at standstill and the measurement of the peak current values of the current leads to the rotor position. Magnetic saturation effect on the saliency is used to distinguish the north magnetic pole from the south. To illustrate our work, we present experimental results for an IPMSM obtained on a floating point digital signal processor (DSP) TMS320C31/40 MHz based control system.

A high-performance sensorless indirect stator flux orientation control of induction motor drive

A new method for the implementation of a sensorless indirect stator-flux-oriented control (ISFOC) of induction motor drives with stator resistance tuning is proposed in this paper. The proposed method for the estimation of speed and stator resistance is based only on measurement of stator currents. The error of the measured q-axis current from its reference value feeds the proportional plus integral (PI) controller, the output of which is the estimated slip frequency. It is subtracted from the synchronous angular frequency, which is obtained from the output integral plus proportional (IP) rotor speed controller, to have the estimated rotor speed. For current regulation, this paper proposes a conventional PI controller with feedforward compensation terms in the synchronous frame. Owing to its advantages, an IP controller is used for rotor speed regulation. Stator resistance updating is based on the measured and reference d-axis stator current of an induction motor on d-q frame synchronously rotating with the stator flux vector. Experimental results for a 3-kW induction motor are presented and analyzed by using a dSpace system with DS1102 controller board based on the digital signal processor (DSP) TMS320C31. Digital simulation and experimental results are presented to show the improvement in performance of the proposed method.

Fail-safe digital implementation of indirect field oriented controlled induction motor drive

Abstract The aim of this paper is to present a full-digital implementation of indirect field oriented controlled (IFOC) induction motor drive with a personal computer (PC) and as much standardized hardware as possible. The complex functions required by IFOC induction motor drive have been executed by PC on line. Computer simulations of the IFOC induction motor drive with tuning rotor resistance have been carried out to test the validity of the proposed method at nominal and zero speed. For the experimental prototype, we use a current regulated-pulse width modulated-voltage source inverter (CR-PWM-VSI) fed induction motor drive. Experimental results of the IFOC induction motor drive obtained on a PC-based system are presented.

Implementation of Improved Sliding Mode Observer and Fault Tolerant Control for a PMSM Drive

This paper presents the development and experimentation of Fault-Tolerant Control (FTC) for sensorless Permanent Magnet Synchronous Motor (PMSM) drive with stator resistance tuning. In the fault-tolerant inverter, a redundant leg is added to replace the faulted leg. Consequently, the proposed inverter is a modified topology inverter with fault-tolerant capability, which can be configured as 3-phase 8-switch inverter. The detection of the faulty leg is based only on the output inverter currents measurement. To make toggle to a redundant leg in case of fault occurrence, a Fault Detection and Isolation (FDI) algorithm is proposed in this paper. Experimental results are presented using a 1.4kW, three poles three-phases PMSM. These results show that the proposed FDI algorithm is able to detect and to isolate the open-phase fault in PMSM drive.

Rotor time constant identification in vector controlled induction motor applied flux model reference adaptive system (MRAS)

The indirect field-oriented control (IFOC) technique brought on a renaissance in modern high-performance control of PWM inverter fed induction motor drives. This method requires the actual value of the rotor time constant which is used to calculate the magnitude and the position of the rotor flux. This value varies widely with rotor temperature and flux level of the machine. So, the quality of the drive system decreases if no means for compensation or identification is applied. This paper describes a rotor time constant identification method in order to update control gains of a vector controlled induction motor. A flux model reference adaptive system (MRAS) is used to estimate the inverse rotor time constant by only using measurements of the stator voltages and currents and rotor speed of an induction motor. The estimated rotor time constant is used as feedback in a vector speed control system for voltage-controlled pulse width modulation (PWM) inverter fed induction motor. The proposed method identifies the inverse rotor time constant with a good accuracy at any load and speed references. Simulation results point out the validity of the proposed method.<<ETX>>

Sensor-less direct torque control of permanent magnet synchronous motor drive using Extended Kalman filter

This paper presents the control of the speed problem for a Sensor-less Direct Torque Control (DTC) of permanent magnet synchronous motor (PMSM), using the Extended Kalman Filter algorithm (EKF) by only measuring the phase voltages and motor currents. Also, due to an angle modification scheme with error tracking, the Sensor-less drive system is robust to parameter variations. Simulation result is provided to verify the proposed approach based on the EKF.

Induction machine parameters and state estimation using Kalman filter approach

Parameter estimation of induction machines is very important especially when indirect field oriented control (IFOC) is applied. This paper presents The application of the Kalman filter to estimate conjointly the state and parameters of a three phase induction machine.

Extended Kalman Filter for Sensorless Fault Tolerant Control of PMSM with Stator Resistance Estimation

Efficiency, reliability, high power quality and continuous operation are important aspects in electric vehicle attraction system. Therefore, quick fault detection, isolation and enhanced fault-tolerant control for open-switches faults in inverter driving systems become more and more required in this filed. However, fault detection and localization algorithms have been known to have many performance limitations due to speed variations such as wrong decision making of fault occurrence. Those weaknesses are investigated and solved in this paper using currents magnitudes fault indices, current direct component fault indices and a decision system. A simulation model and experimental setup are utilized to validate the proposed concept. Many simulation and experimental results are carried out to show the effectiveness of the proposed fault detection approach.The inverter with critical loads should be able to provide critical loads with a stable and seamless voltage during control mode change as well as clearing time. The indirect current control has been proposed for providing stable voltage with critical load during clearing time and seamless control mode transfer of inverters. However, the islanding detection is difficult since with the indirect current control the magnitude and frequency of voltage do not change when the islanding occurs. The conventional anti-islanding method based on the magnitude and frequency of voltage variation cannot apply to the indirect current control. This paper proposes an islanding detection method for the indirect current control. The proposed islanding detection method can detect the islanding using reactive power perturbation and observation when the frequency and magnitude of voltage don’t vary during clearing time. In order to verify the proposed anti-islanding method, the experimental results of a 600W three-phase inverter are provided.

Direct torque control of three-phase PMSM with one switch of inverter open fault

In this paper, direct torque control (DTC) of a three phase permanent magnet synchronous motor (PMSM) one switch open-circuit fault is described. An extra inverter leg is employed to provide the current path during the fault operation.

A Time-Varying Gain Super-Twisting Algorithm to Drive a SPIM

To acquire a performed and practical solution that is free from chattering, this study proposes the use of an adaptive super-twisting algorithm to drive a single-phase induction motor. Partial feedback linearization is applied before using a super-twisting algorithm to control the speed and stator currents. The load torque is considered an unknown but bounded disturbance. Therefore, a time-varying switching gain that does not require prior knowledge of the disturbance boundary is proposed. A simple sliding surface is formulated as the difference between the real and desired trajectories obtained from the indirect rotor flux oriented control strategy. To illustrate the effectiveness of the proposed control structure, an experimental setup around a digital signal processor (dS1104) is developed and several tests are performed.