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EPE 2001 - Topic 06e: Adjustable Speed Drive Systems
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2001 - Conference > EPE 2001 - Topic 06: ELECTRICAL MACHINES AND ADJUSTABLE SPEED DRIVES > EPE 2001 - Topic 06e: Adjustable Speed Drive Systems
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	A cost optimised direct drive for low-speed industrial applications   By G. Göransson; L. Sjöberg; J. Reinert	[View]   [Download]
Abstract: This paper entails the selection of a drive suited best for applications demanding variable low-speed operation at low production costs and high reliability. According to the specification, different possible drives are first compared to each other before detailed design considerations for the chosen solution, a 3-phase switched reluctance drive, is presented. Along with experimental results, considerations for a cost optimised motor and converter design are given.
	A MV AC Drive with Active Front End and Improved Performance   By N. Zargari; M. Pande; J. Wiseman; S. Rizzo	[View]   [Download]
Abstract: A new Curent Source Inverter (CSI)-based Medium Voltage ac drive with Active Front End (AFE), sensorless vector control and Symmetric Gate Commutated Thyristors (SGCTs) is presented. The paper emphasizes a PWM rectifier front end since this configuration can meet the IEEE-519 requirements without the need for an isolation or multi winding transformer. The proposed drive operates the SGCTs with minimal snubbers and at a higher switching frequency than GTOs. This results in a reduction in the size of the filter components and improved performance characteristics while maintaining minimum component count. The paper describes the direct sensorless vector control adapted for Current Source inverters and focuses on the implementation and application issues of the PWM rectifier and the control strategy. Two 4160V drives (600hp and 1250hp) are tested and the steady state and dynamic response to load/speed changes is presented and discussed.
	A Novel High Power Factor Speed Controlled Subsynchronous Cascade   By R. Fuentes	[View]   [Download]
Abstract: The subsynchronous cascade is a well known induction motor (rotor winding ) drive that is used for speed regulation in a range not much below synchronous speed. It operates regenerating active power back into the main AC lines. However, it presents a low power factor in most of the cases. In this paper a novel low cost and improved power factor subsynchronous cascade is presented. The characteristics of the proposed drive under braking operation are also discussed.
	An Improved Control Scheme for a Doubly Fed Induction Machine   By R. Ghosn; C. Asmar; M. Pietrzak-David; B. De Fornel	[View]   [Download]
Abstract: In previous works we defined a control strategy for a Doubly Fed Induction Machine (DFIM) that divides the electrical power between stator and rotor. We now study a new control method that gives better decoupling between d and q axis, and then higher performances for flux, torque and speed responses. This method is almost insensitive to the variations of the stator and rotor resistances.
	Clutch and variable gear based on the principle of an electromagnetic   By R. Surtmann	[View]   [Download]
Abstract: Usually, adjustable speed drives consist of an electrical machine being fed via a converter with the appropriate voltage, current, frequency and the power required by angular speed times torque and the losses. This new concept of an electromagnetic gearing provides speed adjustability in fine steps, includes also the function of a clutch and allows a variation of torque and speed independent of the power delivered to the electromagnetic coupling device. The mechanical coupling is accomplished by magnetical forces which can be influenced by a converter controlled excitation system consisting of a high number of individually controlled coils. This paper explains the functional principle and the test on a special test bench and presents the method of calculating the torque respectively the peak value of torque transferability with respect to the displacement between the magnetic poles. The power electronics and converter control realisation is described as well as the measuring equipment necessary for evaluation of this new principle. The first measurement results at the test bench are shown.
	Control Strategies of Induction Motor Fed by Tandem Converter   By M. Imecs; I.I. Incze; C. Szabó	[View]   [Download]
Abstract: The paper deals with vector control structures for the “tandem” frequency converter fed induction motor drives. This type of converter is composed of an amplitude-modulated current-source inverter and a PWM voltage-source one connected in parallel arrangement. In tandem operation mode the two converters require synchronization in time and in the magnitude of the currents in order to avoid energy circulation between them, otherwise the low power range PWM inverter will be uncontrolled overloaded. In comparison with an equivalent PWM converter in tandem running of the two component ones the switching losses will be smaller because the most part of the energy is transferred without modulation. Due to the voltage-source behaviour of the tandem converter it needs special control structures, where the PWM inverter will have the role of the motor actuator. Rotorfield- oriented vector control methods using “bang-bang” current-feedback modulation and voltage feedforward PWM are presented, and compared with stator-field-oriented vector control suitable only for proper stator-voltage control. Performance problems of the different control schemes related to PWM methods, control variable computation and orientation-field identification are outlined. Three characteristic control structures for induction motor drive systems were simulated using MATLABSimulink- environment.
	Control structures for multimachine multiconverter systems   By A. Bouscayrol; B. Davat; B. de Fornel; B. François; J. P. Hautier; F. Meibody-Tabar; E. Monmasson; M. Pietrzak-David; H. Razik	[View]   [Download]
Abstract: A multi-machine multi-converter system formalism has been proposed in order to describe systems composed of several electrical machines and converters. In this paper, this formalism is extended to the control structures of some of them, which own specific couplings. An example of each coupling type is given: electrical coupling (paralleling converter), magnetic coupling (double-star induction machine), mechanical coupling (electric vehicle).
	Direct Flux Control Of Induction Motor Drives   By G.M. Asher; M. Sumner; F. Cupertino; A. Lattanzi	[View]   [Download]
Abstract: This paper introduces an original control technique for induction motor drives. The technique is based on the control of the angle between the stator and rotor fluxes. It is simpler than the standard vector control schemes with only one PI controller (for the speed controller), and it guarantees a faster torque response. To verify the effectiveness of the proposed control strategy, an experimental comparison with the indirect field orientated vector control strategy is presented.
	DTC strategy for Multi-machine Multi-inverter industrial system   By J. Belhadj; I. Belkhodja; B. De Fornel; M. Pietrzak-David	[View]   [Download]
Abstract: The basic aim of this paper is to apply the Direct Torque Control (DTC) strategy to an industrial multimachine multi-inverter system. Different functioning scenarios are analyzed to study the complexity of this system. Mechanical and electrical couplings constitute the principal operation difficulty of this system mainly when one of the machines is perturbed. Speeds and tension controls are designed and their performances are analyzed and compared with those obtained with a Flux Oriented Control (FOC).
	Effect of load on acoustic noise radiated from PWM controlled inductio   By Z.Q. Zhu; L. Xu; D. Howe	[View]   [Download]
Abstract: The paper systematically reports theoretical and experimental investigations of the effect of load conditions on the acoustic noise radiated by PWM controlled induction machines. The current and noise spectra, as well as the sound pressure level, are measured and analysed as both switching frequency and load are varied. The origins of the noise sources on load were identified, particularly those due to the interaction of permeance field harmonics and mmf field harmonics associated with current harmonics, and the measured noise frequencies are compared with theoretical predictions.
	Flux-guided control strategy for pulse pattern changes   By C. Evers; K. Wörner; F. Hoffmann; A. Steimel	[View]   [Download]
Abstract: A flux-guided regime for pulse pattern changes (PPC) of quasi-synchronous pulse patterns without unwanted transients for high power inverter drive is presented. Contrasting known timer-controlled strategies the orientation at the stator flux guarantees predictable distortions in torque and current at the PPC's too. Characteristics are explained and verified by measurements.
	High Performance Anti-Windup Control for Speed Servo System   By K. Ohishi; E. Hayasaka	[View]   [Download]
Abstract: Generally, a speed servo system of vector-controlled induction motor has a limitation of motor voltage and motor current. When the speed servo system has a large torque reference, the output of its PI controller is often saturated. In this case, the conventional servo system stops the integral calculation of its PI controller. However, this system often has a large overshoot and/or an oscillated response caused by both a windup phenomenon and phase error on vector control condition. This paper proposes a new anti-windup control method for the speed servo system of vector-controlled induction motor. The proposed method compensates the phase error on vector control condition, and always keeps the vector control condition. The experimental results show that the proposed system well regulates a motor speed and a motor secondary magnetic flux for a large torque reference without a windup phenomenon.
	Implementation of a lowcost sinusoidal supply for BLDC Motor   By F. Bonvin; Y. Perriard	[View]   [Download]
Abstract: In many applications, industry tries to develop sinusoidal supply for BLDC Motor. This paper describes a method that still keeps a simple 2 phases-ON sensorless method and achieves a sinusoidal supply, which is needed to avoid speed oscillation due to the very low mechanical constant of small motors. The method is based on back-EMF sensing. Principles, measures and extensions are proposed. The results of industrial applications are exposed and discussed.
	Implementation of Modified MRAC to Drives Control   By P. Crnošija; Z. Ban	[View]   [Download]
Abstract: Model reference adaptive control and self-tuning controller are the most frequently used adaptive methods. Model reference adaptive control with parameter adaptation and self-tuning controller need more iteration for optimal tuning of controller parameters and new tuning of controller parameters for changed plant parameters. The main advantage of a model reference adaptive control scheme with signal adaptation is that it acts optimally in the first change of reference and disturbance value and that it does not need new tuning for changed plant parameters. The implementation of reference model and signal adaptation algorithm for adaptive control of electrical drives is discussed. The basic structure of an MRAC with signal adaptation algorithm is described. The modified structure of a signal adaptation mechanism with adjustable reference model of a plant and/or adjustable observer, which eliminates high frequency oscillation from the plant is described. An MRAC with a modified signal adaptation algorithm has been implemented on a dc motor drive. The presented oscillograms show that the influence of parameter variation and load torque can be quickly and significantly reduced by using the plant reference model and modified signal adaptation algorithm.
	Instantaneous Power Control of Induction Machines   By R. E. Betz; B.J. Cock	[View]   [Download]
Abstract: High performance induction machine control is usually implemented using field oriented control (FOC) or direct torque control (DTC). These strategies both have their strengths and weaknesses. The concept of instantaneous power control (IPC) has been used previously in power compensators and to control the voltage on the DC link of drive systems, but it is a new concept for the control of induction machines. By simultaneously controlling the instantaneous real and imaginary power flowing into the machine it is possible to control the machine’s instantaneous torque and flux. The algorithm to achieve this is more robust to machine parameter inaccuracies compared to the classical field oriented control, and is capable of similar dynamic performance to field oriented and direct torque control. This paper develops the IPC algorithm, and then presents simulation results of its performance. Special emphasis is given to the effects of practical issues such as parameter accuracy and inverter dead time on the performance of the algorithm.
	Inverter ac drives with two-phase and three-phase PWM techniques   By S. Halasz; S. Pravadalioglu	[View]   [Download]
Abstract: Inverter-fed ac drives with two- and three-phase PWMs are compared from the point of view of motor harmonic losses, torque ripples and inverter losses. The skin effect in rotor bars is taken into account. The novel three-phase PWM, which can be constructed similar to the space vector method, is suggested. This method produce scarcely lower harmonic losses and considerable lower torque ripples than the space vector method. Computations are valid for two different, 3.3kHZ and 2kHz transistor switching frequencies assuming that the whole or only 2/3rd of rotor resistance is affected by skin effect. A special care was devoted to the overmodulation region. For this a novel two-phase PWM schemes are suggested. For the same transistor switching frequency the fundamental voltage - where the two-phase and three-phase PWMs produce the same losses - virtually does not depend on the skin. In the whole normal voltage region the motor torque ripples and speed oscillations for the same switching frequency are lower for the three-phase PWMs. This is true especially for the suggested three-phase PWM since in this case the first side modulation harmonics do not produce torque harmonics. The frequency converter conduction and switching losses in the case of the usually used two-phase PWM are about the same than those in the case of three-phase PWMs.
	Large Capacity High Efficiency 3-Level GCT Inverter System   By M. Koyama; Y. Shimomura; H. Yamaguchi; M. Mukunoki; H. Okayama; S. Mizoguchi	[View]   [Download]
Abstract: The number of large capacity voltage source inverters using GTO thyristors applied to steel rolling mill drives is increasing due to their advantages such as high power factor and high output frequency. Further improvement in power conversion efficiency is desired for these voltage source inverters. This paper presents a new large capacity (12MVA) high efficiency three-level inverter using GCT thyristor with world’s largest capacity of 6kV/6kA. In this paper, we describe several key techniques such as high performance GCT gate drive circuit and snubber-less main circuit developed to realize this new GCT inverter. Some experimental results are shown to demonstrate that the developed GCT inverter has enough robustness and reliability to be applied for the steel main rolling mill drives.
	Overview of Reduced Parts Converter Topologies for AC Motor Drives   By Byoung-Kuk Lee	[View]   [Download]
Abstract: THIS PAPER WAS WITHDRAWN FROM THE EPE 2001 CONFERENCE !!!
	Power Converter Filtering Techniques design for Very High Speed Drive   By M.Carpita; D. Colombo; A. Monti; A. Fradilli	[View]   [Download]
Abstract: Recently industry started to show interest on very high speed, high power drives. In designing this kind of drives several problem must be faced, both on the power converter and on the motor. ABB is now studying an experimental high power, high speed drive based on PM motor. One of the main problems in designing the drive is to supply the motor with a good voltage waveform from the harmonics point of view. One possible solution is to put a suitable passive filter between the power converter and the motor. In this paper three different solutions are described: a complete passive power filter, a decoupled control with passive filter and a sliding mode approach.
	Single Stator Double Rotor Machine with independent controlable shafts   By M. Schrödl; S. Ojak; W. Zukrigl	[View]   [Download]
Abstract: This paper introduces a machine based on the DUOMOTOR® principle, consisting of one stator and two rotors. These rotors are beared uniliteral and can be controlled independently of each other. The paper starts with a mathematical model of this new kind of machine and presents its control structure, which is based on a digital signal processor system. The processor system reads all the necessary machine parameters and controls the inverter, which switches the electrical power for the DUOMOTOR® machine.
	Speed Control of an Induction Motor with Acceleration Feedforward Cont   By J-W. Lee; S-H. Kim	[View]   [Download]
Abstract: In this paper, a novel speed control strategy using an acceleration feedforward compensation by the estimation of the system inertia is proposed. With the proposed method, the enhanced speed control performance can be achieved and the speed response against the disturbance torque can be improved for the vector-controlled induction motor drive systems in which the bandwidth of the speed controller cannot be made large enough. The simulation and experimental results confirm the validity of the proposed strategy.
	Stability Analysis of Digital Current Vector Control of AC-Machines   By M. Riese; J. Bechtler	[View]   [Download]
Abstract: Current vector control based on the discrete model of ac-machines has been shown to enable fast torque impression and decoupling of field- and quadrature axis currents. The respective controller design may however lead to an unstable disturbance response, depending on the motor parameters. A solution is presented and verified by measured results.
	The Research of Torsional Vibration Suppression of Ship Elevator   By X. Ma; Q. Jiang; B. Wang	[View]   [Download]
Abstract: Torsional vibration caused by shaft spring and mechanical gaps is one of the problems of the Yangtze-Gorges ship elevator. The reason of torsional vibration and the suppression methods are approached in this paper. To simplify analysis, a 2 motor-1 shaft (2M-1S) system is investigated first and the results of analysis are verified by simulation and experiment. Then a 4 motor-4 shaft (4M-4S) system is simulated and its results show that it is reasonable to simplify the 4M-4S system by the 2M-1S system.
	Var.-Speed Asynch. Drives Employing Structural Harmonic Elim. Techn.   By P. Bolognesi; D. Casini; L. Taponecco	[View]   [Download]
Abstract: It still exists many practical applications of induction motors whose performance requirements are limited to soft startup and gross speed adjustability with acceptable torque profile, while a low drive cost constitutes a key issue. In such cases, conventional solutions are still employed since advanced inverter drives result usually not attractive for such purposes, due to a too high cost / actual benefits ratio. This paper proposes the application of simple structural harmonic elimination methods as low-complexity modulation techniques for low-end, low-cost inverter drives for induction motors employing the scalar V/f regulation strategy. The employ of a very simple control system, a low switching frequency inverter and a standard single-winding motor should in fact permit to offer such drives with a limited overcost with respect to conventional solutions, which could be accepted considering the achievable adjustability improvements. Design considerations and simulation results are reported.
	Vector Controlled Induction Drive System for Direct Driven Elec. Vehic   By M. Khawatmi	[View]   [Download]
Abstract: The paper deals with a new method for simultaneous speed and rotor resistance estimation in vector controlled induction motor drive system, with emphasis on its’ application in Direct Driven Electrical Vehicle. The direct rotor field orientation method has been chosen as vector control strategy. In order to estimate the rotor flux components, a Robust Adaptive Flux Observer has taken into consideration [1,3]. The simultaneous speed and rotor resistance estimation is performed only using the model of the induction motor together with statistical algorithms.