MRAS-Type Speed and Flux Estimator with Additional Adaptation Mechanism for the Induction Motor Drive

This paper deals with a novel Model ReferenceAdaptive System (MRAS) estimator of the rotor flux andspeed reconstruction for induction motor drive. Theproposed estimator is based directly on the mathematicalmodel of the induction motor. In comparison with existingmethods the additional variable is introduced, which has toreduce partly the estimator sensitivity to the rotor timeconstant changes. Chosen simulation tests of the proposedsolution are presented

Struktura upravljanja indukcijskog motora otporna na kvarove

In this paper the Fault Tolerant (FT) vector controlled induction motor drive system is described and tested in various drive conditions. The influence of the rotor speed sensor faults on the properties of the analyzed drive are tested. Faults detection algorithms, based on different algorithms are developed and described. The results of the simulation carried out using the MATLAB/SimPowerSystem software are verified in experimental tests in MicroLabBox DS1202, in a wide range of motor speed changes. The proposed detection algorithms can be successfully applied in the Fault Tolerant Drive Systems (FTDS).U ovom radu opisan je sustav za vektorsko upravljanje indukcijskim motorom otporno na kvarove. Sustav je testiran u različitim uvjetima rada. Testiran je utjecaj kvarova rotorskog senzora brzine na svojstva analiziranog sustava. Razvijeni su i opisani različiti algoritmi za detekciju kvarova. Simulacijski rezultati u MATLAB/SimPowerSystem provjereni su eksperimentalno u MicroLabBox DS1202 za široki raspon promjena brzine motora. Predloženi algoritam se može uspješno primjeniti u sustavima upravljanja otpornima na kvarove

Analiza kvarnih stanja rotora vektorski upravljanog asinkronog stroja bez mehaničkog senzora brzine vrtnje

In the paper an analysis of the Direct Field Control of induction motor drive with broken rotor bars is presented. A drive system with and without a mechanical speed sensor is analyzed. In the sensorless induction motor (IM) drive the rotor flux and speed is reconstructed with the use of a MRASCC estimator, where the induction motor is used as a reference model. The stator current estimator and current model of the rotor flux are used as adapted models. Most of the speed estimators used in sensorless drives are sensitive to motor parameter changes, especially to the rotor resistance changes. The proposed MRASCC estimator is very robust to all motor parameter changes, hence it should work properly in a faulty rotor. In the paper simulation and experimental results of the sensorless IM drive with broken rotor bars are presented. Characteristic frequency harmonics of the IM state variables connected with the broken rotor bars are introduced. The low speed region and the dynamic properties of the IM drive with rotor faults are tested. The range of stable work of the control system is shown.U radu je prikazano izravno upravljanje poljem asinkronog motora s prekinutim rotorskim štapovima. Analiziran je elektromotorni pogon s mehaničkim senzorom brzine i bez njega. Pri upravljanju bez mehaničkog senzora brzine rotorski tok i brzina rekonstruirani su korištenjem MRASCC estimatora, pri čemu je asinkroni stroj korišten kao referentni model. Estimator statorske struje i strujni model rotorskog toka korišteni su za adaptaciju modela. Većina estimatora brzine vrtnje koji se koriste u pogonu bez mehaničkog senzora brzine osjetljivi su na promjenu parametara stroja, posebno na promjenu rotorskog otpora. Predloženi je MRASCC estimator robustan na promjene parametara motora pa je moguć rad i u kvarnom stanju rotora. U radu su prikazani simulacijski i eksperimentalni rezultati pogona bez mehaničkog senzora brzine pri prekinutim rotorskim štapovima. Uvedene su frekvencije karakterističnih harmonika varijabli stanja asinkronog motora povezane s prekinutim rotorskim štapovima. Analizirano je područje malih brzina vrtnje te dinamičke značajke pogona s asinkronim motorom s rotorom u kvarnom stanju. Prikazano je područje stabilnog rada sustava upravljanja

Universal Speed and Flux Estimator for Induction Motor

In the paper, the concept of universal speed and flux estimator with additional parameters estimators is presented. Proposed solution is based on the Model Reference Adaptive System (MRAS) type flux and speed estimator and can be used in different industrial systems (especially in the automotive applications). Induction Motor (IM) parameters are estimated using the systems based only on simple simulators and adaptive systems (voltage model and current model). Proposed system was tested in the sensorless induction motor drive with the Direct Field Oriented Control (DFOC) algorithm. Simulation and experimental results are presented in the paper

A Current Sensor Fault Tolerant Control Strategy for PMSM Drive Systems Based on Cri Markers

The paper describes a vector-controlled fault tolerant control (FTC) structure for permanent magnet synchronous motor (PMSM) drives. As a control algorithm, the classical field oriented control was applied. For the proper operation of this drive, minimum two current sensors are necessary, however, in the FTC drives additional redundant transducers are applied. Each measuring sensor, including current sensors, are susceptible to damage and can lead to unstable operation of the drive. The presented control structure, with a diagnostic and compensation system, is robust to the typical current sensor faults—lack of signal, intermittent signal, variable gain, signal noise and signal saturation. The fault detection algorithm is based on the signal method. The fault diagnostic system is tested in two control algorithms—the scalar control and vector control ones—to demonstrate the transient of the faulted signals, detection signals and detection time. After current sensor fault appearance, its influence on the control structure, especially speed transient, is compensated using non-sensitive components. The analysis is presented for all the abovementioned faults for different speed conditions

Application of rotor resistance identification algorithm for real-time diagnostics of induction motor

W artykule omówiono możliwość wykrywania uszkodzenia prętów klatki wirnika silnika indukcyjnego z zastosowaniem techniki opartej na identyfikacji parametrów schematu zastępczego maszyny. Metodyka ta bazuje na założeniu, że wybrane uszkodzenia mogą objawiać się zmianami parametrów silnika, a ich identyfikacja w czasie rzeczywistym i obserwowanie tych zmian pozwala na wczesną identyfikację uszkodzenia. W pracy wykorzystano fakt, że w przypadku pęknięcia prętów klatki wirnika symptomem uszkodzenia jest wzrost rezystancji schematu zastępczego wirnika. Do odtwarzania tego parametru zastosowano estymator adaptacyjny z modelem odniesienia (MRAS). Badania silnika indukcyjnego przeprowadzono w układzie bezpośredniego sterowania polowo zorientowanego (DFOC). W artykule przedstawiono wyniki badań symulacyjnych oraz eksperymentalnych.This paper deals with the broken rotor bars detection in squirrel-cage induction motor using parameter identification approach. This method is based on the assumption, that the chosen failures may result in motor parameters variations. Real-time identification and observation of parameters variation allows to incipient fault detection. Increase of the rotor resistance value may be a good fault symptom, in the case of rotor bar damage. In the paper, the rotor resistance estimator based on the model reference adaptive system (MRAS) is utilized. The induction motor is operating in the direct field-oriented control structure, under different conditions. In the paper simulation and experimental results are shown

Experimental Analysis of the Current Sensor Fault Detection Mechanism Based on Cri Markers in the PMSM Drive System

In this paper the current sensor fault detector for the permanent-magnet synchronous motor drive system has been presented. The solution is a known method used for induction motor drive systems, tested by authors in simulation for the PMSM drive system. The application is based on the current markers, which enable not only failure detection, but also the location of said failures. Detector operation is based only on the analysis of measurements from current sensors and does not require additional information about other state variables. The aim of the work is to present simulation and experimental studies in field-oriented control (FOC) for the tested current sensor fault detector for various operating conditions of the drive system—variable speed and load

Design and Analysis of Current Sensor Fault Detection Mechanisms for PMSM Drives Based on Neural Networks

This paper describes a vector-controlled Permanent Magnet Synchronous Motor (PMSM) drive system with the current sensor fault detection mechanism. In general, the control structure is based on the well-known Field Oriented Control (FOC) algorithm. The structure is equipped with an additional algorithm for current sensor fault detection based on a neural network. The presented control structure is able to detect typical current sensor faults, such as lack of signal, intermittent signal, variable gain and signal noise. The application of the NN detector guarantees a faster detection of the sensor fault than classical detectors based on algorithmic methods or logical systems. This work focuses on presenting the methodology of designing detectors and their analysis, based solely on simulation analysis. The simulation results, conducted in the Matlab/Simulink environment, are presented for the above-mentioned faults in phase A and phase B for different speed conditions

Experimental Analysis of the Current Sensor Fault Detection Mechanism Based on Cri Markers in the PMSM Drive System

In this paper the current sensor fault detector for the permanent-magnet synchronous motor drive system has been presented. The solution is a known method used for induction motor drive systems, tested by authors in simulation for the PMSM drive system. The application is based on the current markers, which enable not only failure detection, but also the location of said failures. Detector operation is based only on the analysis of measurements from current sensors and does not require additional information about other state variables. The aim of the work is to present simulation and experimental studies in field-oriented control (FOC) for the tested current sensor fault detector for various operating conditions of the drive system—variable speed and load

Modified Rotor Flux Estimators for Stator-Fault-Tolerant Vector Controlled Induction Motor Drives

This paper deals with fault-tolerant control (FTC) of an induction motor (IM) drive. An inter-turn short circuit (ITSC) of the stator windings was taken into consideration, which is one of the most common internal faults of induction machines. The sensitivity of the classic, well-known voltage and current models to the stator winding faults was analyzed. It has been shown that these classical state variable estimators are sensitive to induction motor parameter changes during stator winding failure, which results in unstable operation of the direct field-oriented control (DFOC) drive. From a safety-critical applications point of view, it is vital to guarantee stable operation of the drive even during faults of the machine. Therefore, a new FTC system has been proposed, which consists of new modified rotor flux estimators, robust to stator winding faults. A detailed description of the proposed system is presented herein, as well as the results of simulation and experimental tests. Simulation analyses were performed using MATLAB/Simulink software. Experimental tests were carried out on the experimental test bench with a dSpace DS1103 card. The proposed solution could be applied as an alternative rotor flux estimation technique for the modern FTC drive