Mongi Moujahed

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.

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.

Fault-Tolerant Voltage Source Converter for Wind-Driven Doubly Fed Induction Generator Connected to a DC Load

This paper presents a fault-tolerant Voltage Source Converter (VSC) for Field Oriented Control (FOC) of a stand-alone Doubly Fed Induction Generator (DFIG) connected to a DC load. In the proposed topology, the stator of the DFIG is connected to a DC load through a diode rectifier, while the rotor is connected to the DC load through a VSC. This topology allows the integration of DFIG in the hybrid system with other sources of production and storage, such as photovoltaic system, connected to the same DC bus. The fault-tolerant VSC consists in incorporating a fourth leg to replace the faulted leg. A fault detection scheme for switch device open-circuit faults is proposed in this study. The novelty of this method consists in analyzing the rotor currents within normal and faulty operating modes. Simulation results are presented for a 3.7kW DFIG-DC system with single open-circuit faults that validate the methods presented in this study. The effectiveness of the proposed fault detection method has been validated...

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.

Sensorless DTCSVM fault tolerant of PMSM based on MRAS

This section presents a structure of a control topology of a PMSM, whose objective is to eliminate the mechanical sensor and ensure continuity of service even fault presence opening a phase. A MRAS observer is used to replace the mechanical sensor and a redundant inverter leg is used to replace the faulty leg.

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.