Moncef Gossa

Sensorless Indirect Stator Field Orientation Speed Control for Single-Phase Induction Motor Drive

The industrial requirements for the control of an induction machine without a mechanical sensor continue to be of interest, as evidenced by the most recent publications. The focus is on improvements of control without a mechanical sensor. A new method for the implementation of a sensorless indirect stator-flux-oriented control (ISFOC) of a single-phase induction motor (SPIM) drive is proposed in this paper. The proposed method of rotor speed estimation is based only on the measurement of the main and auxiliary windings stator currents and that of a reference q-axis current generated by the control algorithm. The error of the measured q-axis current from its reference value feeds the proportional plus integral controller, the output of which is the estimated slip angular frequency. Experimental results for sensorless ISFOC speed control of a SPIM drive are presented and analyzed using a dSPACE system with DS1104 controller board based on the digital signal processor TMS320F240. Digital simulation and experimental results are presented to show the improvement in performance of the proposed sensorless algorithm.

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.

Multiple IGBTs open circuit faults diagnosis in voltage source inverter fed induction motor using modified slope method

This paper deals with multiple insulated gate bipolar transistor (IGBTs) open circuit faults detection and localization in a pulse width modulation (PWM) voltage source inverter (VSI) fed induction motor based on a modified slope method. Firstly, a detection algorithm was used to calculate the slope of the current-vector trajectory in complex plan αβ. This algorithm detects the faulty bridge. Second, the Schmitt-trigger is used for the phases currents monitoring. This circuit determines the phases currents polarity and detect whether the current in the faulty arm is positive or negative. The analysis of two combined information makes it possible to diagnose the two simultaneous IGBTs open circuit fault within inverter. The proposed technique is developed and implemented to vector control induction motor drives. An experimental setup in the laboratory is used to compare the simulation results and the experimental results and to evaluate the performances of the proposed method.

Three-stage Kalman filter for state and fault estimation of linear stochastic systems with unknown inputs

Abstract The paper studies the problem of simultaneously estimating the state and the fault of linear stochastic discrete-time varying systems with unknown inputs. The fault and the unknown inputs affect both the state and the output. However, if the dynamical evolution models of the fault and the unknown inputs are available the filtering problem will be solved by the Optimal three-stage Kalman Filter (OThSKF). The OThSKF is obtained after decoupling the covariance matrices of the Augmented state Kalman Filter (ASKF) using a three-stage U–V transformation. Nevertheless, if the fault and the unknown inputs models are not perfectly known the Robust three-stage Kalman Filter (RThSKF) will be applied to give an unbiased minimum-variance estimation. Finally, a numerical example is given in order to illustrate the proposed filters.

Real-time implementation of IRFOC for Single-Phase Induction Motor drive using dSpace DS 1104 control board

Abstract Single Phase induction Motors (SPIMs) are one of the widely used motors in the world. This explains the interest accorded by researchers on the improvement of the quality and performances of these motors. The availability of low-cost static converters makes possible the economic use of energy and improvement of the quality of the electromagnetic torque in the SPIM. Nowadays, Indirect Rotor-Field-Oriented Control (IRFOC) techniques brought on a renaissance in modern high-performance control of PWM inverter fed SPIM. In this paper, an IRFOC system is proposed for SPIMs including a relatively simple and effective decoupling scheme. This is achieved by introducing two new decoupling signals to the system. However, model asymmetry in SPIMs causes extra coupling between two stator windings. To use the field orientation control, the asymmetry must be eliminated by using an appropriate variable changing. A computer simulation of the IRFOC for Single-Phase Induction Motor drive is carried out to test the validity of the proposed method at nominal and zero speed. The design, analysis, and implementation for a 1.1-kW Single-Phase Induction Motor are completely carried out using a dSPACE DS1104 digital signal processor (DSP) based real-time data acquisition control (DAC) system, and MATLAB/Simulink environment. Digital simulation and experimental results are presented to show the improvement in performance of the proposed algorithm.

Open phase faults detection in PMSM drives based on current signature analysis

This paper deals with monitoring condition of electrical failures in variable speed of permanent magnet synchronous motor (PMSM) drives by stator current signature analysis. The objective of this study is to develop a detection method for the open phase fault in PMSM drives. The main idea consists in minimizing the number of sensors allowing the open stator phase fault of the system to study. The harmonics produced by current spectral analysis fault-related components are studied. The current waveform patterns for various modes of open phase winding are investigated. Simulation and experimental results are presented using a 1.1 kW, 6 poles three-phase PMSM. Comparison of simulation and experimental results show that the method is able to detect the open-phase fault in PMSM drive.

PWM-Switching pattern-based diagnosis scheme for single and multiple open-switch damages in VSI-fed induction motor drives

This paper deals with a fault detection technique for insulated-gate bipolar transistors (IGBTs) open-circuit faults in voltage source inverter (VSI)-fed induction motor drives. The novelty of this idea consists in analyzing the pulse-width modulation (PWM) switching signals and the line-to-line voltage levels during the switching times, under both healthy and faulty operating conditions. The proposed method requires line-to-line voltage measurement, which provides information about switching states and is not affected by the load. The fault diagnosis scheme is achieved using simple hardware and can be included in the existing inverter system without any difficulty. In addition, it allows not only accurate single and multiple faults diagnosis but also minimization of the fault detection time to a maximum of one switching period (T(c)). Simulated and experimental results on a 3-kW squirrel-cage induction motor drive are displayed to validate the feasibility and the effectiveness of the proposed strategy.

An improved diagnosis technique for IGBTs open-circuit fault in PWM-VSI-fed induction motor drive

This paper deals with an improved technique for insulated-gate bipolar transistors (IGBTs) open-circuit fault diagnoses in voltage source inverter (VSI) fed induction motors. The extraction of the fault information is based on the combining of the switching pattern and the electric drive line-to-line voltage measurements. The combined diagnosis signals make possible to detect and identify the single and multiple open-circuit faults of the inverter switches. Furthermore, only one line-to-line voltage is necessary to diagnose two inverter legs simultaneously. For simplicity and cost-effectiveness, the fault detection is carried out by a simple circuit. To avoid the false diagnosis alarms, the time delays due to turn-on and turn-off process of the power switches are compensated while acting on the switching pattern. Different from the conventional method, the proposed technique was marked by a better time delay between the fault occurrence and its detection. The Simulation results are displayed to confirm the proposal.

Novel optimal recursive filter for state and fault estimation of linear stochastic systems with unknown disturbances

Novel optimal recursive filter for state and fault estimation of linear stochastic systems with unknown disturbances This paper studies recursive optimal filtering as well as robust fault and state estimation for linear stochastic systems with unknown disturbances. It proposes a new recursive optimal filter structure with transformation of the original system. This transformation is based on the singular value decomposition of the direct feedthrough matrix distribution of the fault which is assumed to be of arbitrary rank. The resulting filter is optimal in the sense of the unbiased minimum-variance criteria. Two numerical examples are given in order to illustrate the proposed method, in particular to solve the estimation of the simultaneous actuator and sensor fault problem and to make a comparison with the existing literature results.

Doubly fed induction generator (DFIG) in wind turbine modeling and power flow control

In this work, the doubly fed induction generator (DFIG) for wind energy conversion system is studied. First, the dq model of the wound rotor induction machine in rotor reference frame and then how it can be implemented in simulink for fast simulations. In order to control the power flowing between the stator of (DFIG) and the grid, a control law is synthesized using PI controllers. Simulation results have demonstrated its excellent performances, with stator flux orientation control (SFOC).