EPE Association: EPE 2009 - Subtopic 10-5 - DS: 'Induction Machines, Switched Reluctance Machines'

EPE 2009 - Subtopic 10-5 - DS: 'Induction Machines, Switched Reluctance Machines'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 10: 'Electrical Machines' > EPE 2009 - Subtopic 10-5 - DS: 'Induction Machines, Switched Reluctance Machines'

   [return to parent folder]

   A New class of Resonant Discharge Drive Topology for Switched Reluctance Motor
By EBRAHIM AFJEI, MAJID ASGAR, ALIREZA SIADATAN [View]
[Download]

Abstract: Switched Reluctance Motor (SRM) drive has a remarkable characteristic, which makes it attractive for high-speed in low voltage applications. In this paper, a new drive circuit from the bridge family which uses resonant circuit during discharge period is presented. The new topology provides faster rate of current discharge, the basic control strategy for a switched reluctance motor drive circuit is explained. New class of resonant discharge topologies for SRM drive circuit is presented. These topologies provides faster rate of fall for the phase current, which permits the motor to operate at higher speeds. In the new circuits a capacitor is connected in series with the motor winding. In addition, an energy recovery circuit, the stored magnetic energy that fall to trap on resonant capacitor in due discharge period recovered from it by the single quadrant chopper comprising of one transistor, capacitor and diode sent to the dc source. A capacitor is charged resonantly by a use of motor phase windings during the phase turn off periods and then discharged via an inductor and a diode during the next working strokes. A detailed explanation and demonstration of the converter circuits have been presented.

   A New Hybrid Two Phase Switched Reluctance Motor/Generator
By EBRAHIM AFJEI, ALIREZA SIADATAN [View]
[Download]

Abstract: The switched reluctance motor is a simple and robust machine, which has found application over a wide power and speed ranges in different shapes and geometries. This paper introduces a new configuration for a two phase unidirectional switched reluctance motor/field assisted generator. The proposed novel motor/generator consists of two magnetically independent stator and rotor sets (layers), where each stator set includes four salient poles with windings wrapped around them, while the rotor comprises of two salient poles with different arc lengths and no windings. There is a stationary reel, which has the field coils wrapped around it and is placed between the two-stator sets. In the motor mode of operation the two sets are connected independently. In this connection the stator poles in each layer can have both North and South Pole configurations. In the generator mode, the stator poles in one set can have either north or South Pole configuration while the stator poles in the other set (layer) have the opposite pole arrangements. In this format, the developed magnetic field from the stator poles travels to the rotor then to the rotor shaft and finally completes its path via the motor/ generator housing. To evaluate the motor performance, two types of analysis, namely, the numerical technique and the experimental study have been utilized. In the numerical analysis, the finite element analysis is employed, where as in the experimental study, a proto-type motor has been built and tested.

   A New Position Sensorless Control for Switched Reluctance Motor
By Yojiro MIURA [View]
[Download]

Abstract: This paper describes a new estimation method of rotor position for 3-phase SRM based on the space vector of the phase inductance at standstill and during rotating condition. The rotor position is simply obtained without magnetic characteristics of the motor and additional hardware. In this method, assuming the phase inductance waveform to be sine wave, the rotor position is obtained by computing the angle of the space vector of inductance. The space vector of inductance is calculated by the phase voltage and current. At stand still, all phase inductances are estimated by applying DC bus voltage to all phases. At low speeds, the rotor position estimation is carried out by applying DC bus voltage to the idle phases over a short time. Excited phase inductance is calculated by sum of each phase inductance. At high speeds, the inductance of the excited phase is used to estimate the rotor position. In magnetic saturation region, using simplified magnetization curves, we can obtain the rotor position without the effect of saturation. The validity of the proposed method is verified by experimental results.

   An Improvement to Standard Polyphase Induction Machine Efficiency Tests Utilizing Direct Online Stator Winding Resistance Measurement
By Ralph FELDMAN, keith BRADLEY, ZHANG HE, Matteo TOMASINI, Patrick WHEELER [View]
[Download]

Abstract: A direct online stator winding resistance measurement scheme is proposed as a means to improve standard efficiency tests of polyphase induction machines. To enable resistance measurement a DC current is injected online into the stator winding and response voltages are captured. In experimental tests an unequal number of anti-parallel diodes has been used to inject DC current. A bespoke temperature controlled shunt has been used to improve accuracy of DC current measurement. Experimental results from a standard efficiency test conducted to IEC 60034-2-2007 on a 15 kW 3 phase induction motor are presented.

   Comparison of Induction Motor FEM simulations fed by measured and reconstructed DTC inverter voltages
By Lassi AARNIOVUORI, Lasse LAURILA, Markku NIEMELÃ„, Juha PYRHÃ–NEN [View]
[Download]

Abstract: A coupled system simulator, based on analytical circuit equations and a finite element method (FEM) model of the motor, is used to analyze a direct-torque-controlled (DTC) frequency-converter-fed industrial 200 kW squirrel-cage induction motor. The measured stator voltage waveforms are used as inputs to the FEM motor model, and the results are compared with the measured ones. Comparison is also made for the simulation results obtained by reconstructed stator voltages. The converter switch states are solved from the measured voltage waveform, and used as inputs of the simulator inverter bridge. The performance of the FEM motor model is analyzed, and the amplitudes of the measured stator current harmonics are kept as references.

   Dynamic Modelling of the SRM using the Macromodelling Approach:Comparison of Simulation and Experiment
By Nizar KHATEEB, klaus MÃœHLBAUER, Dieter GERLING [View]
[Download]

Abstract: When an electric machine is designed, a dynamic model of the machine is advantageous in order to predict the electromagnetic, electric and mechanical behavior. In this paper a new modeling method of the dynamic behavior of the switched reluctance motor is presented. It bases on the macromodelling approach, which gives the advantages of minimum input data for the simulation and acceptable flexibility. A high accuracy of the model is proved through a comparison between simulation and experiment. Therefore the dynamic model of the switched reluctance motor is integrated in a drive simulation-platform, which contains controller and power electronic converter.

   Dynamics of Diesel-Generator-Units during Direct-on-Line Starting of Induction Motors
By Marija MIROSEVIC, Zlatko MALJKOVIC, Mato MISKOVIC [View]
[Download]

Abstract: The paper analyses dynamics of diesel-generator-unit during direct-on-line starting of induction motors. Mathematical model of integral motor drives has been developed, consisting of: diesel engine, synchronous generator and motor drives fed directly from generator unit terminals. The aim is to compare dynamics during starting loaded induction motors with different loads.

   End-winding Effect on Shaft Voltage in AC Generators
By JAFAR ADABI, Firuz ZARE, Arindam GHOSH [View]
[Download]

Abstract: This paper presents effects of end-winding on shaft voltage in AC generators. A variety of design parameters have been considered to calculate the parasitic capacitive couplings in the machine structure with Finite Elements simulations and mathematical calculations. End-winding capacitances have also been calculated to have a precise estimation of shaft voltage and its relationship with design parameters in AC generators.

   Estimation of the Leakage and Magnetizing Inductances of Induction Motors
By MARIO CACCIATO, ALFIO CONSOLI, Giuseppe SCARCELLA, GIACOMO SCELBA [View]
[Download]

Abstract: In addition to the IEEE Standard Test Procedure for Induction Motors (IM), several advanced methods have been presented to achieve higher accuracy on parameters estimation. Some of them allow to estimate with high precision only a specific parameter, while others improve the parameters estimation at the price of high computational efforts and time due to finite elements analysis or the use of recursive algorithms. After a survey of the main typologies adopted to estimate the electrical parameters in IMs, that highlights the main advantages and drawbacks of each category, this paper presents a novel procedure that can be adopted as parameters estimation. According to the proposed method the motor parameters are calculated through locked-rotor tests performed as the motor is fed by a standard inverter, by exploiting simple relationships which do not increase the computation effort. Simulation and experimental results have been performed on different motors and, comparing the proposed approach to other methods, they have confirmed its validity.

   Feasibility Study of Switched Reluctance Motors Made of Permendur
By Yu HASEGAWA [View]
[Download]

Abstract: This paper investigates the possibility of utilizing a switched reluctance (SR) motor made of permendur. Motor torque, iron loss, and efficiency of the SR motor are evaluated by finite element method (FEM). Furthermore, a suitable structure for the SR motor made of permendur is presented.

   Induction Motor made of Iron Powder Core
By MASAYUKI MORIMOTO [View]
[Download]

Abstract: In this paper, induction motor of which stator core is made of iron powder (Soft Magnetic Composite: SMC) is presented. The comparison of the performance of SMC induction motor and conventional laminated induction motor is shown. As the result, efficiency difference between SMC motor and conventional laminated motor is only 3.7\% in spite of the permeability of SMC is 20\% lower than conventional laminated steel iron.

   Magnetic Circuit Analysis of a Linear Switched Reluctance Motor
By Jordi G. AMORÃ“S, Pere ANDRADA [View]
[Download]

Abstract: In this paper a magnetic circuit analysis has been developed to obtain flux linkage/current characteristics in aligned and unaligned positions for a Linear Switched Reluctance Motor. The model is based on lumped parameters and it takes into account the leakage pole flux and the end effects. The proposed lumped parameter magnetic analysis can be a useful tool for designing Linear Switched Reluctance Machines. The procedure has been verified by means of two dimensional finite element analysis and experimental measurements.

   Neural Network Torque Estimator for Switched Reluctance Motor
By Constantin PAVLITOV, Hao CHEN, Yassen GORBOUNOV, Tzanko GEORGIEV, Wang XING, Xiaoshu ZAN [View]
[Download]

Abstract: The neural network torque estimator is based on the identification model of SR motors. It is derived from this model using the concept of superposition of elementary models. The estimator can be applied in SRM controllers where the limitation of dynamic torque is of importance. It is also useful for torque ripple reduction.

   On-line broken bars detection diagnosis by parameters estimation
By Imene BEN AMEUR BAZINE [View]
[Download]

Abstract: The authors propose a new diagnosis method for on-line broken bars detection by parameters estimation. For predictive detection, Kalman filtering algorithm has been adapted to take into account the on-line parameters deviations in faulty case. Within the framework of the diagnosis of the rotor defects, it is difficult to conduct experimental tests to validate the on-line identification of such default. For this reason, one propose an on-line technique to detection rotor broken bars. This technique was validated by simulation tests using an induction machine simulator. The goal of this identification is to detect a possible variation in the resistance of the bars, signature of a rotor defect. Estimation results show a good agreement and demonstrate the possibility of on-line motor barâ€™s break detection.

   Self-Tuning Approach to Optimization of Excitation Angles for Switched-Reluctance Motor Drives Using Fuzzy Adaptive Controller
By Hassan MORADI, S YARI, A.R YARI, Ebrahim AFJEI [View]
[Download]

Abstract: This paper presents a fuzzy adaptive control scheme for Automatic Control of excitation angles in Switched-Reluctance Motor (SRM) Drives. A turn-on and Turn-off angles play important roles in developing electromagnetic torque in SRM. The value of excitation angles are usually variable and depend upon the motor speed and other parameters of the inverter that excites the SRM. As the motor speed increases the shape of the current waveform, changes in such way that limits the production of motoring torque. At high speeds, it is possible for the phase current never reaches the desired value due to motor phase inductance, therefore, the torque falls off. In order to remedy this problem, the phase turn on angle is advanced in such way that the phase commutation begins sooner. Advancing the commutation angle offers the advantages of getting the current into the phase winding while the inductance of the phase is low, and also of having a little more time to get the current out of the phase winding before the rotor reaches the negative torque region. Since the SRM drive is a variable speed motor then, the amount of advancing for the turn on and turn off angles should be accomplished automatically according to the speed of the motor. In order to optimize the timings of the Turn-on and Turn-off angles, on-line rotor position is detected and then the angular speed is calculated. The computed optimum timing of excitation angles by use of fuzzy adaptive controller are then fed into a commutation logic block. This block decides on the proper phase winding to be energized. Control of the excitation angles result in either positive net torque for motoring or negative net torque for generating which optimizes the torque at high speed. This technique is then applied to an experimental SRM drive system in speed ranging from 0 to 12000 rpm. Experimental operation shows this technique provides much higher torque production for the motor.

   Stator Faults Diagnosis of the Converter-fed Induction Motor using Symmetrical Components and Neural Networks
By Czeslaw KOWALSKI, Marcin WOLKIEWICZ [View]
[Download]

Abstract: The paper deals with the diagnostic problems of the converter-fed induction motors in the case of stator faults. For diagnostic purposes the neural detector was developed trained and tested using measurement data of negative components of the stator current and impedance, for different levels of stator failures, load torque and converter frequencies. Feedforward neural network with very simple internal structure used for the detection of fault level gave satisfactory results, what is very important in practical realization.

   SWITCHED RELUCTANCE MOTOR FOR ELECTRIC POWER-ASSISTED STEERING
By PERE ANDRADA GASCON, BalduÃ BLANQUÃ‰ MOLINA, EUSEBI MARTÃNEZ PIERA, IGNACI PERAT BENAVIDES, JOSEP ANTONI SÃNCHEZ LÃ“PEZ, MARCEL TORRENT BURGUES [View]
[Download]

Abstract: In this paper, switched reluctance motors (SRM) are proposed as an alternative for electric power assisted steering (EPAS) applications. The new 42 V power voltage system is a very attractive design for a steering electric motor, both from a cost and size perspective. A four-phase 8/6 SRM drive is designed for a rack type EPAS which should provide a maximum force of 10 kN. Two-dimension finite element analysis is used to validate the design.

   Torque-Ripple in AC Switched Reluctance Generators
By ABELARDO MARTINEZ, ESTANIS OYARBIDE, CARLOS EDUARDO MONTAÃ‘O, SYLVIA MENDEZ, EDUARDO LALOYA, JAVIER VICUÃ‘A, FRANCISCO JOSE PEREZ-CEBOLLA [View]
[Download]

Abstract: In this paper a switched reluctance machine is used as an AC switched reluctance generator. Each phase resonates with a parallel capacitor and the circuit is tuned to match the generation speed. It is shown that in each phase of the experiments energy flows from the prime mover to the machine and the opposite within each cycle. The superposition of all the phase energy flows results in unidirectional energy transfer from the prime mover to the machine. The resultant torque associated to this function shows a ripple that is reduced with the number of phases of the machine. A machine model based on Finite Element data is used to illustrate the torque involved in the generation process. An experimental set-up with a four-phase machine is used to test the simulations. The phases are star connected and the energy obtained charges a battery bank by rectifying the AC voltage. As the resonant frequency can be fitted to a specific rotor speed by changing the capacitance, the system can generate energy at variable speed. It may be suitable for small wind mills to load batteries in isolated sites.

   Using two PSO-structure approaches to estimate induction machine parameters.
By Mhamed BOUNEKHLA, Ahmed OULD-AISSA [View]
[Download]

Abstract: This work deals with a parametric identification using the least square method based on the output error. An appropriate particle swarm optimization algorithm is applied as a technique to minimize the objective function in order to obtain simultaneously the electrical and the mechanical parameters. The validation and comparison of the two algorithms used are obtained from experiments carried out on different machines.

EPE 2009 - Subtopic 10-5 - DS: 'Induction Machines, Switched Reluctance Machines'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 10: 'Electrical Machines' > EPE 2009 - Subtopic 10-5 - DS: 'Induction Machines, Switched Reluctance Machines'
	[return to parent folder]

	A New class of Resonant Discharge Drive Topology for Switched Reluctance Motor By EBRAHIM AFJEI, MAJID ASGAR, ALIREZA SIADATAN	[View] [Download]
Abstract: Switched Reluctance Motor (SRM) drive has a remarkable characteristic, which makes it attractive for high-speed in low voltage applications. In this paper, a new drive circuit from the bridge family which uses resonant circuit during discharge period is presented. The new topology provides faster rate of current discharge, the basic control strategy for a switched reluctance motor drive circuit is explained. New class of resonant discharge topologies for SRM drive circuit is presented. These topologies provides faster rate of fall for the phase current, which permits the motor to operate at higher speeds. In the new circuits a capacitor is connected in series with the motor winding. In addition, an energy recovery circuit, the stored magnetic energy that fall to trap on resonant capacitor in due discharge period recovered from it by the single quadrant chopper comprising of one transistor, capacitor and diode sent to the dc source. A capacitor is charged resonantly by a use of motor phase windings during the phase turn off periods and then discharged via an inductor and a diode during the next working strokes. A detailed explanation and demonstration of the converter circuits have been presented.

	A New Hybrid Two Phase Switched Reluctance Motor/Generator By EBRAHIM AFJEI, ALIREZA SIADATAN	[View] [Download]
Abstract: The switched reluctance motor is a simple and robust machine, which has found application over a wide power and speed ranges in different shapes and geometries. This paper introduces a new configuration for a two phase unidirectional switched reluctance motor/field assisted generator. The proposed novel motor/generator consists of two magnetically independent stator and rotor sets (layers), where each stator set includes four salient poles with windings wrapped around them, while the rotor comprises of two salient poles with different arc lengths and no windings. There is a stationary reel, which has the field coils wrapped around it and is placed between the two-stator sets. In the motor mode of operation the two sets are connected independently. In this connection the stator poles in each layer can have both North and South Pole configurations. In the generator mode, the stator poles in one set can have either north or South Pole configuration while the stator poles in the other set (layer) have the opposite pole arrangements. In this format, the developed magnetic field from the stator poles travels to the rotor then to the rotor shaft and finally completes its path via the motor/ generator housing. To evaluate the motor performance, two types of analysis, namely, the numerical technique and the experimental study have been utilized. In the numerical analysis, the finite element analysis is employed, where as in the experimental study, a proto-type motor has been built and tested.

	A New Position Sensorless Control for Switched Reluctance Motor By Yojiro MIURA	[View] [Download]
Abstract: This paper describes a new estimation method of rotor position for 3-phase SRM based on the space vector of the phase inductance at standstill and during rotating condition. The rotor position is simply obtained without magnetic characteristics of the motor and additional hardware. In this method, assuming the phase inductance waveform to be sine wave, the rotor position is obtained by computing the angle of the space vector of inductance. The space vector of inductance is calculated by the phase voltage and current. At stand still, all phase inductances are estimated by applying DC bus voltage to all phases. At low speeds, the rotor position estimation is carried out by applying DC bus voltage to the idle phases over a short time. Excited phase inductance is calculated by sum of each phase inductance. At high speeds, the inductance of the excited phase is used to estimate the rotor position. In magnetic saturation region, using simplified magnetization curves, we can obtain the rotor position without the effect of saturation. The validity of the proposed method is verified by experimental results.

	An Improvement to Standard Polyphase Induction Machine Efficiency Tests Utilizing Direct Online Stator Winding Resistance Measurement By Ralph FELDMAN, keith BRADLEY, ZHANG HE, Matteo TOMASINI, Patrick WHEELER	[View] [Download]
Abstract: A direct online stator winding resistance measurement scheme is proposed as a means to improve standard efficiency tests of polyphase induction machines. To enable resistance measurement a DC current is injected online into the stator winding and response voltages are captured. In experimental tests an unequal number of anti-parallel diodes has been used to inject DC current. A bespoke temperature controlled shunt has been used to improve accuracy of DC current measurement. Experimental results from a standard efficiency test conducted to IEC 60034-2-2007 on a 15 kW 3 phase induction motor are presented.

	Comparison of Induction Motor FEM simulations fed by measured and reconstructed DTC inverter voltages By Lassi AARNIOVUORI, Lasse LAURILA, Markku NIEMELÃ„, Juha PYRHÃ–NEN	[View] [Download]
Abstract: A coupled system simulator, based on analytical circuit equations and a finite element method (FEM) model of the motor, is used to analyze a direct-torque-controlled (DTC) frequency-converter-fed industrial 200 kW squirrel-cage induction motor. The measured stator voltage waveforms are used as inputs to the FEM motor model, and the results are compared with the measured ones. Comparison is also made for the simulation results obtained by reconstructed stator voltages. The converter switch states are solved from the measured voltage waveform, and used as inputs of the simulator inverter bridge. The performance of the FEM motor model is analyzed, and the amplitudes of the measured stator current harmonics are kept as references.

	Dynamic Modelling of the SRM using the Macromodelling Approach:Comparison of Simulation and Experiment By Nizar KHATEEB, klaus MÃœHLBAUER, Dieter GERLING	[View] [Download]
Abstract: When an electric machine is designed, a dynamic model of the machine is advantageous in order to predict the electromagnetic, electric and mechanical behavior. In this paper a new modeling method of the dynamic behavior of the switched reluctance motor is presented. It bases on the macromodelling approach, which gives the advantages of minimum input data for the simulation and acceptable flexibility. A high accuracy of the model is proved through a comparison between simulation and experiment. Therefore the dynamic model of the switched reluctance motor is integrated in a drive simulation-platform, which contains controller and power electronic converter.

	Dynamics of Diesel-Generator-Units during Direct-on-Line Starting of Induction Motors By Marija MIROSEVIC, Zlatko MALJKOVIC, Mato MISKOVIC	[View] [Download]
Abstract: The paper analyses dynamics of diesel-generator-unit during direct-on-line starting of induction motors. Mathematical model of integral motor drives has been developed, consisting of: diesel engine, synchronous generator and motor drives fed directly from generator unit terminals. The aim is to compare dynamics during starting loaded induction motors with different loads.

	End-winding Effect on Shaft Voltage in AC Generators By JAFAR ADABI, Firuz ZARE, Arindam GHOSH	[View] [Download]
Abstract: This paper presents effects of end-winding on shaft voltage in AC generators. A variety of design parameters have been considered to calculate the parasitic capacitive couplings in the machine structure with Finite Elements simulations and mathematical calculations. End-winding capacitances have also been calculated to have a precise estimation of shaft voltage and its relationship with design parameters in AC generators.

	Estimation of the Leakage and Magnetizing Inductances of Induction Motors By MARIO CACCIATO, ALFIO CONSOLI, Giuseppe SCARCELLA, GIACOMO SCELBA	[View] [Download]
Abstract: In addition to the IEEE Standard Test Procedure for Induction Motors (IM), several advanced methods have been presented to achieve higher accuracy on parameters estimation. Some of them allow to estimate with high precision only a specific parameter, while others improve the parameters estimation at the price of high computational efforts and time due to finite elements analysis or the use of recursive algorithms. After a survey of the main typologies adopted to estimate the electrical parameters in IMs, that highlights the main advantages and drawbacks of each category, this paper presents a novel procedure that can be adopted as parameters estimation. According to the proposed method the motor parameters are calculated through locked-rotor tests performed as the motor is fed by a standard inverter, by exploiting simple relationships which do not increase the computation effort. Simulation and experimental results have been performed on different motors and, comparing the proposed approach to other methods, they have confirmed its validity.

	Feasibility Study of Switched Reluctance Motors Made of Permendur By Yu HASEGAWA	[View] [Download]
Abstract: This paper investigates the possibility of utilizing a switched reluctance (SR) motor made of permendur. Motor torque, iron loss, and efficiency of the SR motor are evaluated by finite element method (FEM). Furthermore, a suitable structure for the SR motor made of permendur is presented.

	Induction Motor made of Iron Powder Core By MASAYUKI MORIMOTO	[View] [Download]
Abstract: In this paper, induction motor of which stator core is made of iron powder (Soft Magnetic Composite: SMC) is presented. The comparison of the performance of SMC induction motor and conventional laminated induction motor is shown. As the result, efficiency difference between SMC motor and conventional laminated motor is only 3.7\% in spite of the permeability of SMC is 20\% lower than conventional laminated steel iron.

	Magnetic Circuit Analysis of a Linear Switched Reluctance Motor By Jordi G. AMORÃ“S, Pere ANDRADA	[View] [Download]
Abstract: In this paper a magnetic circuit analysis has been developed to obtain flux linkage/current characteristics in aligned and unaligned positions for a Linear Switched Reluctance Motor. The model is based on lumped parameters and it takes into account the leakage pole flux and the end effects. The proposed lumped parameter magnetic analysis can be a useful tool for designing Linear Switched Reluctance Machines. The procedure has been verified by means of two dimensional finite element analysis and experimental measurements.

	Neural Network Torque Estimator for Switched Reluctance Motor By Constantin PAVLITOV, Hao CHEN, Yassen GORBOUNOV, Tzanko GEORGIEV, Wang XING, Xiaoshu ZAN	[View] [Download]
Abstract: The neural network torque estimator is based on the identification model of SR motors. It is derived from this model using the concept of superposition of elementary models. The estimator can be applied in SRM controllers where the limitation of dynamic torque is of importance. It is also useful for torque ripple reduction.

	On-line broken bars detection diagnosis by parameters estimation By Imene BEN AMEUR BAZINE	[View] [Download]
Abstract: The authors propose a new diagnosis method for on-line broken bars detection by parameters estimation. For predictive detection, Kalman filtering algorithm has been adapted to take into account the on-line parameters deviations in faulty case. Within the framework of the diagnosis of the rotor defects, it is difficult to conduct experimental tests to validate the on-line identification of such default. For this reason, one propose an on-line technique to detection rotor broken bars. This technique was validated by simulation tests using an induction machine simulator. The goal of this identification is to detect a possible variation in the resistance of the bars, signature of a rotor defect. Estimation results show a good agreement and demonstrate the possibility of on-line motor barâ€™s break detection.

	Self-Tuning Approach to Optimization of Excitation Angles for Switched-Reluctance Motor Drives Using Fuzzy Adaptive Controller By Hassan MORADI, S YARI, A.R YARI, Ebrahim AFJEI	[View] [Download]
Abstract: This paper presents a fuzzy adaptive control scheme for Automatic Control of excitation angles in Switched-Reluctance Motor (SRM) Drives. A turn-on and Turn-off angles play important roles in developing electromagnetic torque in SRM. The value of excitation angles are usually variable and depend upon the motor speed and other parameters of the inverter that excites the SRM. As the motor speed increases the shape of the current waveform, changes in such way that limits the production of motoring torque. At high speeds, it is possible for the phase current never reaches the desired value due to motor phase inductance, therefore, the torque falls off. In order to remedy this problem, the phase turn on angle is advanced in such way that the phase commutation begins sooner. Advancing the commutation angle offers the advantages of getting the current into the phase winding while the inductance of the phase is low, and also of having a little more time to get the current out of the phase winding before the rotor reaches the negative torque region. Since the SRM drive is a variable speed motor then, the amount of advancing for the turn on and turn off angles should be accomplished automatically according to the speed of the motor. In order to optimize the timings of the Turn-on and Turn-off angles, on-line rotor position is detected and then the angular speed is calculated. The computed optimum timing of excitation angles by use of fuzzy adaptive controller are then fed into a commutation logic block. This block decides on the proper phase winding to be energized. Control of the excitation angles result in either positive net torque for motoring or negative net torque for generating which optimizes the torque at high speed. This technique is then applied to an experimental SRM drive system in speed ranging from 0 to 12000 rpm. Experimental operation shows this technique provides much higher torque production for the motor.

	Stator Faults Diagnosis of the Converter-fed Induction Motor using Symmetrical Components and Neural Networks By Czeslaw KOWALSKI, Marcin WOLKIEWICZ	[View] [Download]
Abstract: The paper deals with the diagnostic problems of the converter-fed induction motors in the case of stator faults. For diagnostic purposes the neural detector was developed trained and tested using measurement data of negative components of the stator current and impedance, for different levels of stator failures, load torque and converter frequencies. Feedforward neural network with very simple internal structure used for the detection of fault level gave satisfactory results, what is very important in practical realization.

	SWITCHED RELUCTANCE MOTOR FOR ELECTRIC POWER-ASSISTED STEERING By PERE ANDRADA GASCON, BalduÃ BLANQUÃ‰ MOLINA, EUSEBI MARTÃNEZ PIERA, IGNACI PERAT BENAVIDES, JOSEP ANTONI SÃNCHEZ LÃ“PEZ, MARCEL TORRENT BURGUES	[View] [Download]
Abstract: In this paper, switched reluctance motors (SRM) are proposed as an alternative for electric power assisted steering (EPAS) applications. The new 42 V power voltage system is a very attractive design for a steering electric motor, both from a cost and size perspective. A four-phase 8/6 SRM drive is designed for a rack type EPAS which should provide a maximum force of 10 kN. Two-dimension finite element analysis is used to validate the design.

	Torque-Ripple in AC Switched Reluctance Generators By ABELARDO MARTINEZ, ESTANIS OYARBIDE, CARLOS EDUARDO MONTAÃ‘O, SYLVIA MENDEZ, EDUARDO LALOYA, JAVIER VICUÃ‘A, FRANCISCO JOSE PEREZ-CEBOLLA	[View] [Download]
Abstract: In this paper a switched reluctance machine is used as an AC switched reluctance generator. Each phase resonates with a parallel capacitor and the circuit is tuned to match the generation speed. It is shown that in each phase of the experiments energy flows from the prime mover to the machine and the opposite within each cycle. The superposition of all the phase energy flows results in unidirectional energy transfer from the prime mover to the machine. The resultant torque associated to this function shows a ripple that is reduced with the number of phases of the machine. A machine model based on Finite Element data is used to illustrate the torque involved in the generation process. An experimental set-up with a four-phase machine is used to test the simulations. The phases are star connected and the energy obtained charges a battery bank by rectifying the AC voltage. As the resonant frequency can be fitted to a specific rotor speed by changing the capacitance, the system can generate energy at variable speed. It may be suitable for small wind mills to load batteries in isolated sites.

	Using two PSO-structure approaches to estimate induction machine parameters. By Mhamed BOUNEKHLA, Ahmed OULD-AISSA	[View] [Download]
Abstract: This work deals with a parametric identification using the least square method based on the output error. An appropriate particle swarm optimization algorithm is applied as a technique to minimize the objective function in order to obtain simultaneously the electrical and the mechanical parameters. The validation and comparison of the two algorithms used are obtained from experiments carried out on different machines.