New Publications are available for Velocity, acceleration and rotation control
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New Publications are available now online for this publication.
Please follow the links to view the publication.Motion control strategy and operational behaviour of a high speed bearingless disc drive
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0297
In the last decade, bearingless drives have found their way into applications such as pumps for delicate media like blood [1] or sensitive chemicals [9] as well as drives for bioreactors [13] and chemical process chambers [3]. With all these applications running at relatively low speeds below 15.000rpm, the suitability of bearingless drives for high speed operation remained unclear. This paper will give a brief description of a high speed bearingless disc drive, designed to reach speeds beyond 100.000rpm. Aside from special requirements such as rotor material strength and low stator loss characteristics, the control system also faces new tasks arising from the combined motor - bearing unit. Eventually, the operational behaviour of the constructed prototype on the basis of phase current amplitude and resulting rotor orbit is presented. (6 pages)Motion control for short primary linear drive using induction or synchronous operation in different sections for material handling applications
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0299
The moderate thrust force and high accuracy make the short primary linear motor a good selection for material handling application with very long track and closed paths. This paper deals with the motion control of a linear drive which operates at some sections of the track as synchronous machine and for other sections as induction machine. Unlike applications with long primary linear motors, the costs can be considerably reduced by using an active vehicle on a passive track. In sections where no fast speed changes are necessary, a sensorless speed control method is used. A suitable vehicle motion control strategy is necessary especially during the transition between synchronous to induction motor operation and between sensor based to sensorless region operations. The classic MRAS (Model Reference Adaptive System) speed and flux estimators are activated in the sensorless induction motor operation mode. The transition control strategies are experimentally verified, discussed and presented. (6 pages)Improved maximum power extraction strategy for PMSG based wind energy conversion system
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0325
Even though hill climbing search (HCS) control is the simplest MPPT algorithm that does not require any prior knowledge of the system, it has the disadvantage of being slow in its response. This slowness in the response is due to the number of perturbations involved in climbing the hill and the settling time of the each perturbation. This paper proposes an improved HCS control, in which the nature of the input perturbation is changed, so as to improve the control algorithm's response speed in tracking the maximum power point of a wind turbine. (6 pages)Accurate estimation of electric vehicle speed using Kalman filtering in the presence of parameter variations
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0315
The mechanical drivetrain dynamics of electric vehicles can have a detrimental effect on the performance of the vehicle speed controller. This is mainly caused by the feedback only being available from the motor encoder, with no measurement of the actual vehicle speed. In this paper it is shown how the vehicle driveability can be greatly improved if estimates of vehicle speed and mass are obtained. This has been realised using a Kalman Filter (KF) and a Recursive Least Squares (RLS) estimator, and validated with experimental results. (6 pages)Driving a synchronous motor so that it emulates a twin-shaft gas turbine engine
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0296
This paper presents a model-based control method for using a vector controlled synchronous motor to emulate the behaviour of a twin-shaft gas turbine engine as it drives an electric generator supplying power to steady-state and dynamic loads. The aim of this approach is to provide an in-door test-bed for the generator itself, in the absence of the engine that will eventually be used as prime mover. The control method is validated on a much-smaller (benchtop-scale) hardware-in- the-loop (HIL) implementation of the engine emulator system. The motor speed controller tracks the output speed of a simulated real-time engine model in order to generate appropriate voltage and frequency demands for the variable speed inverter that drives the motor. The inertia of the synchronous motor is varied by adding inertial loading to its shaft in order to study the effect of emulating a prime mover with a higher inertia than the emulator motor. Experimental results show that the emulator motor is able to track the engine speed with excellent accuracy when its inertia is lower than the engine model. But, when the emulator motor inertia is higher than the engine model the speed tracking performance of the motor presents a dynamic lag and it requires a larger control effort. (6 pages)Modeling and speed control of permanent magnet synchronous motor at constant load torque using PSIM
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0411
This paper deals with modeling and speed control of a permanent magnet synchronous Motor (PMSM) drive system in PSIM. At present in drives industry only two types of permanent magnet motors are available. These are Brushless DC Motor (BLDC) drive with a trapezoidal flux distribution and PMSM drive with sinusoidal flux distribution which eliminates the torque ripple caused by the commutation. A closed loop control system with a Proportional Integral (PI) controller and Current controller to control the speed has been designed to operate in constant torque regions and its Implementation has been done in PSIM. PSIM is a software, which has user friendly approach and some basic theories, the corresponding PSIM models for the PMSM can easily be constructed.Speed control of DC motor using Modulus Hugging Approach
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0418
The speed control of separately excited DC motors by PI and PID controller is widely used in industry. A design of controller by applying a several method in analyzing controlled parameter to tune parameter in order to obtain the best process response. A design of PI and PID controller by Modulus Hugging Approach are presented in this paper for testing the performance of controllers in command following control and in disturbance rejection control. From simulation results with LABVIEW, it was found that the con troller was fast response and stable, and the effect of disturbance is fast rejected.Estimation of tip speed ratio using an adaptive perturbation and observation method for wind turbine generator systems
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0133
The main challenge associated with wind turbine generator (WTG) systems is power coefficients vary with operating tip speed ratios (TSR), which are related to wind speed variations. To keep power coefficients at its maximum value, operating TSRs must be held at its optimal value by controlling rotor speeds according to reference rotor speeds at incoming wind speeds using a maximum power point tracking (MPPT) controller. This paper presents a MPPT controller, which is based on a novel TSR observer for estimating TSRs and consequently, reference rotor speeds. It is based on a perturbation and observation (P&O) method, which employs adaptive perturbation step sizes to decrease the time required for estimating TSRs under wind speed variations. (6 pages)Control of induction motors
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0190
Induction motors have existed for many years but were always limited in their application because the supply needed for variable speed control could only be provided by rotary converters, otherwise a three-phase fixed supply could be used to give a fixed-speed control. For this reason induction motors have been used in industrial installations for some time but their use for traction systems has only recently gained widespread acceptance with the advent of cheaper, higher ratings of static inverters and cheaper microprocessors with enough processing power to handle the control.M42 active traffic management monitoring and evaluation: results from hard shoulder running up to 60 mph
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0364
Active Traffic Management (ATM) schemes (now called Managed Motorways) aim to address congestion and improve Journey Time Reliability (JTR) by utilising a set of advanced Intelligent Transport Systems applications to make as much use of the available capacity as possible. This paper presents the results obtained from the impact assessment of Hard Should Running up to 60 mph on traffic conditions over the M42-ATM section. The analysis does not cover safety data as at least 3 years worth of safety data is required for a valid safety analysis. (6 pages)Reductions in fuel consumption and CO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub> emissions with specs average speed enforcement
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0375
Data was gathered on passenger car fuel consumption at various speeds, and compared with traffic speed profiles for unenforced motorways and motorways enforced with SPECS average speed cameras to determine the potential fuel savings and CO<sub xmlns="http://pub2web.metastore.ingenta.com/ns/">2</sub> reductions that may be achieved by enforcing the national speed limit on UK motorways. (5 pages)Robust control of a wind turbine
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0906
The wind turbine is represented as an uncertain plant whose parameters depend on the wind speed. A two degree-of-freedom turbine speed controller is designed by using the technique of μ-synthesis. The frequency responses and time responses of the closed-loop system show a satisfactory performance of the linearized system. It is demonstrated that by relaxing the robustness requirements it is possible to achieve acceptable performance of the nonlinear closed-loop system as well. (5 pages)A design of multi-axis motion controller for welding robot based on DSP
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.1328
To satisfy the motion control for wielding robot, a design of multi-axis motion controller based on DSP is proposed in this paper. The hardware structure and the software structure are discussed in detail. The motion controller consists of three DSP control cards. There are two control units which can control two servo motors in one DSP control card. So the controller can control six servo motors at the same time. The motion controller can perform high accuracy and high velocity interpolation. It communicates with the upper computer through dual-port RAM. More axis controlling can be achieved by adding more DSP control cards with bus card. The absolute position is detected by motion controller. A variety of control mode can be achieved includes position control, velocity control and torque control. The interpolation algorithm is presented. The experiment data indicates that the motion controller has the advantages of good real-time performance and highly machining accuracy.Minimal configuration PI fuzzy gain scheduling speed controller in indirect vector controls scheme
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0151
Paper deals with design of minimal configuration PI fuzzy gain scheduling speed controller in induction motor indirect vector control scheme. Others controllers in control scheme are not of interest. Results gained by simulations and experiments for deferent speed controllers design has been compared. Simulations are carried out via Matlab/Simulink software. Experimental results are gained via dSPACE DS1104 digital control card and experimental model. (6 pages)Integration of a mean-torque diesel engine model into a hardware-in-the-loop shipboard network simulation
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0026
This paper describes the creation of a hardware-in-the-loop demonstrator for use in evaluating network architecture and control concepts for marine electrical systems, as well as specific items of equipment. The demonstrator allows a scaled hardware network to be connected to a simulation of a multi-megawatt marine diesel prime-mover, coupled via a synchronous generator. This allows "more-electric" marine scenarios to be investigated without large-scale hardware trials. The method of closing the loop between simulation and hardware is described, with particular reference to the control of the laboratory synchronous machine which represents the simulated prime-mover. The throttle control to the laboratory machine requires two nested "PIDA" proportional-integral-derivative-acceleration controllers, to achieve tight phase matching with the simulation. The limit on simulation fidelity is the speed with which field current can be slewed, which requires more powerful field drive hardware than was used during this paper. (6 pages)Optimal flux loss model based of speed sensorless vector control induction motor
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0005
The paper presents a cheap and accurate loss model based controller to improve the efficiency and the power factor of the speed sensorless controlled induction motor. The proposed controller calculates the optimal air gap flux verifying high efficiency especially at light load, improving the power factor, and stable operation for a high load step disturbance. The proposed model is cheap where no additional hardware is required. The accuracy and the fast response of the proposed controller in comparison with an online search control method are proved by the experiment results. The efficiency, and the power factor improvements for speed sensorless induction motor by using the optimal flux compared with the rated flux are examined experimentally. (6 pages)Performance improvement of V/f induction -motor control in the low-frequency range
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1843
Open-loop V/f controlled induction-motor drive can experience undesirable sustained oscillations at low frequencies. To reduce these oscillations, this paper first synthesizes the basic V/f speed control for achieving appropriate V/f ratios and boost voltages under light and high loads in the low-frequency range. It also highlights and includes in tuning the impacts of motor parametric variations occurring during operation. The paper then optimizes a closed-loop control scheme for slip compensation with a PI (proportional-integral) controller by applying GA (genetic algorithm) for tuning its parameters. Simulation results show that the optimized closed-loop control stabilizes the operation of the motor drive at low frequencies. The optimized control achieves also near-zero steady-state speed errors for both light and high loads at frequencies above the motor minimum starting frequency. (6 pages)An instantaneous model and its implementation in speed regulator for HEV engine
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1394
In this paper, a transient dynamic model is proposed for the hybrid electric vehicle (HEV) engine for the purpose of alleviation of high frequency oscillations in engine revolutions, which is extended to develop a digital governor providing a high fidelity estimation of rotary speed oscillation for hybrid vehicle engines. To damp speed oscillation, a speed governor is implemented for HEV engine speed regulation. By comparison between measured and estimated signals, it is demonstrated that a good agreement has been achieves and the governor behaves an excellent damping speed ripple. (5 pages)Fuzzy control of the ram velocity in energy-saving servo injection molding machines
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1514
Since the injection velocity controller for the energy-saving servo drive system is essential, new type energy-saving servo system is becoming one of the hot development directions of injection molding machines. However the nonlinearity and irregular changes of load in the actual injection molding process makes injection speed control complicated. In this paper, an energy-saving servo injection control system using fuzzy control theory based on the re-establishment mathematical model of servo motor-driving fixed pump is presented, including the inputs/outputs of the system and their membership functions and the fuzzy control rule bank. The simulation results according to the parameters of Haitian plastics machinery indicated that the fuzzy controller can effectively reduce injection velocity tracking error. Additionally the system is good-robust compared with the traditional PID controller. (5 pages)Operation of brushless doubly-fed machine for drive applications
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080539
This paper presents dynamic and steady-state performance of the Brushless Doubly-Fed Machine (BDFM) operating as a variable speed drive. A simple closed-loop control system is used which only requires a speed feedback. The controller is capable of stabilising the machine when changes in speed and torque are applied. The machine starts in cascade mode and then makes a transition to the synchronous mode to reach the desired speed. This will allow a uni-directional converter to be used. The experiments included in this paper were carried out on a 180 frame size BDFM.A new fuzzy logic based adaptation mechanism for MRAS sensorless vector control induction motor drives
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080507
This paper proposes a novel adaptation mechanism to replace the classical PI controller used in model reference adaptive speed estimation schemes which are based on rotor flux. The proposed adaptation mechanism is based on a fuzzy logic strategy. A detailed experimental comparison between the new and conventional schemes is carried out in both open and closed loop sensorless modes of operation when a vector control drive is working at very low speed. Superior performance has been obtained using the new fuzzy logic adaptation mechanism in both modes of operations.E-VIVEGAM - sim card based vehicle speed control system (SIMCON)
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080147
The above words have a lot more meaning than they may seem to have. The so called globalised world of today pushed by the thirst for money has inexorably led to a hectic mechanical life. This craze of the people had made men forget the values of humanity and the very basic necessity for existence has been pathetically forgotten. 'Break the rules' the fashionable slogan of the age has been so ardently followed by the people.Rules seem to be existent only in paper and not in actual life. One of those many such violations is manifested in the form of fatal accidents induced by undisciplined road users. It is high time that the so called regulations which reside as mere documents serving the purpose of no one be enforced without compromise. So our idea is to regulate traffic smoothly by using a mechanism to make sure that the speed of the vehicle is not exceeded beyond the set speed limit.Comparison of two position and speed estimation techniques used in PMSM sensorless vector control
http://dl-live.theiet.org/content/conferences/10.1049/cp_20080597
The paper describes the comparison between two different high-performance techniques used for the sensorless estimation of the motor shaft position in Permanent Magnet Synchronous Motor Sensorless Drives. Rotor position and speed are estimated from measured terminal voltages and currents, and are used as feedback in a sensorless vector control scheme, achieving almost the same high-performance of a sensored drive. The paper point out the differences, by using experimental implementation, between an open-loop flux estimator based on the electrical model of the machine, and a reduced flux observer.A generalized approach to the design of the speed control system for inverter-driven permanent magnet synchronous motor
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070653
Different types of control schemes have been suggested for variable speed AC drives fed from static power sources. Among them, field oriented control employing vector control strategies has become quite popular in recent years. A disadvantage of the scheme when applied to synchronous motor drives is that the motor always operates at a lagging power factor.In this work, a generalized design strategy is suggested for the speed control loop of an inverter-fed synchronous motor drive, in which, its inherent flexibility to generate the same torque for different combinations of currents, is exploited that can achieve more general types of control. Existing control schemes such as unity power factor control, torque angle control, as well as field-oriented control etc can be obtained as special cases. The scheme has been validated through extensive simulations as well as laboratory experiments.Micro-controller based closed loop control of induction motor using V/F method
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070634
Recent advances in semi-conductor technology and implementation of micro-controller have made it easier to use AC Motors in speed control applications. The proposed paper, deals with variable speed drives of induction motor for constant torque using V/F ratio method. The above system is designed with closed loop where the actual speed of motor is compared with the reference speed. The difference in the speed is adjusted by changing firing angles of switching devices and there by obtaining variable speeds. The system is tested for its performance and is also recorded under various conditions. Introduction of microcontroller in performing the speed control of the induction motor makes it more flexible when compared with other traditional methods.Distributed generation based dynamic voltage restorer
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070621
Dynamic voltage restorer (DVR), either battery or rectifier supported, is proposed for compensation of voltage sag in the literature. The drawback of battery fed DVR is limited capacity. Rectifier supported DVR may not be limited, from the capacity point-of-view. But, the operation of DVR may become impractical, when the source is remotely located. One of the solutions, to overcome the above drawbacks, is distributed generation (DG). As the distributed generation (DG) sources are distributed in nature, and the capacity ranges from kilowatt (kW) to few megawatt (MW), this paper, proposes DG for energizing DVR. Modeling of DVR fed with (generator based) DG, with the main aim of voltage (injected by DVR) and speed (of the generator) control, is presented. Voltage injected by DVR (fed with a standalone generator, through a rectifier) is carried by amplitude modulation (AM). Speed control of DG, is carried by a simple PI control scheme. Simulation studies, show the (voltage sag) compensation capability of the proposed DG-fed-DVR, with faster dynamic performance.Novel topologies for identification and control of PMSM using artificial neural network
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070590
Rotor speed and performance of permanent magnet synchronous motor (PMSM) suffers from accuracy due to variation of motor parameters such as stator resistance, stator inductance or torque constant. The conventional linear estimators are not adaptive. Neural networks (ANN) have shown better results when estimating or controlling nonlinear systems. In this paper an artificial neural network based high performance speed control system for a PMSM with different topologies and their performance comparison is presented. The main purpose is to achieve accurate trajectory control of the speed, when the motor and load parameters are unknown. The PMSM motor was identified using three different topologies (speed, voltage and current). The unknown nonlinear dynamics of the motor and the load are captured by the ANN. The performance of the identification and control algorithm are evaluated by simulating them on a typical PMSM motor model.Fault-tolerant speed measurement for the control of a DC-motor
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070033
This paper describes a control system that has been designed to handle sensor faults and therefore could be considered as fault-tolerant control one. The fault tolerant controller is based on the output of the speed sensor and two speed observers. The first one is a suboptimal Kalman filter based on the state model of the machine. The second one is based on the estimation of the frequency of one "rotor slot harmonic" present in the DC current signal which contains speed information. The two observers guarantee the best dynamic and steady state performances required by the application and also improve the reliability in the event of sensor loss or sensor recovery. The fault tolerant controller reorganization is based on a control decision block which depends on the steady state and dynamic performances of the two observers. The results of the control system show the effectiveness of this approach in the event of speed sensor loss and recovery. (6 pages)Reliability in electromagnetic systems: the role of electrical contact resistance in maintaining automobile speed control system integrity
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070027
Electromagnetic systems depend upon the integrity of electrical connections. An intermittent speed sensor connection is shown to generate a false speed signal that may allow an automobile speed control system to engage at low speed and cause a sudden acceleration. Preventive measures are discussed. The current approach to controlling uncommanded sudden accelerations seems to rely upon the driver braking against full engine power to bring the vehicle to a halt. More effective and safer control would be achieved by cutting off the fuel supply the moment that an uncommanded wide open throttle condition was detected, thereby preventing the sudden acceleration. (6 pages)Closed loop controlled PMDC motor drive
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070632
This paper deals with the control of speed regulation of a separately excited PMDC motor fed from single phase fully controlled converter. In many industries , the PMDC motor plays a vital role for variety of control applications. The speed regulation of separately excited PMDC motor is poor in discontinuous mode when fed from single phase fully controlled converter. The aim of this work is to implement an efficient controller like PI, PD and PID for PMDC drive operating in discontinuous mode of the converter. In this work it is observed that the PI controller delivers superior performance than any other controller in the discontinuous mode of the converter, in achieving better speed regulation. Simulation results prove the effectiveness of the proposed PI controller compared with other controllers.Modeling and control of a distributed generation system
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070620
This paper presents a new mathematical model for a standalone synchronous machine based distributed generation (DG) system, with the main aim of load voltage and machine speed control. The DG system consists of a standalone synchronous generator, connected to a controlled rectifier with a resistive load. For the mathematical model developed, a control scheme has been designed for maintaining desired voltage (at the load) and generator speed, in the presence of load variations and changing reference inputs. Results obtained both through the MATLAB programming and PSCAD/EMTDC simulation are presented to validate the derived model, and to demonstrate the better performance of the control scheme in maintaining load voltage and generator speed at the desired values.Interconnection and damping assignment approach for reliable PM synchronous motor control
http://dl-live.theiet.org/content/conferences/10.1049/ic_20070036
The goal of this paper is to design a high performance speed controller for a PMSM drive. The controller is passivity based using the energy shaping technique namely interconnection and damping assignment. Under some assumptions, a linear controller is derived associated to a non linear observer to estimate the load torque which is unknown. The important point developed in this paper is the proof of the global stability, which is mandatory in a drive especially in embedded or transportation applications where reliability is a key issue. Simulation and experimental results prove the feasibility of the approach. (6 pages)Control of induction motors
http://dl-live.theiet.org/content/conferences/10.1049/ic_20060201
Induction motors have existed for many years but were always limited in their application because the supply needed for variable speed control could only be provided by rotary converters, otherwise a three-phase fixed supply could be used to give a fixed-speed control. For this reason induction motors have been used in industrial installations for some time but their use for traction systems has only recently gained widespread acceptance with the advent of cheaper, higher ratings of static inverters and cheaper microprocessors with enough processing power to handle the control. It is assumed in this paper that other authors explain the details of induction motor operation and power electronic inverters; only the aspects relevant to controlling induction motors will be dealt with here.A new fuzzy sliding-mode control for MW variable speed-variable pitch wind turbine
http://dl-live.theiet.org/content/conferences/10.1049/cp_20062102
Recently, an increasing number of larger wind turbines (1 MW and up) are being developed with a variable speed-variable pitch control mechanism. The main objective of using a variable speed-variable pitch control strategy is to improve the fast response speed and get maximum energy. But the power generated by wind turbine changes rapidly because of the continuous fluctuation of wind speed and direction. At the same time, wind energy conversion systems are of strong nonlinear characteristics because of many uncertain factors. Based on combined nonlinear sliding-mode control and fuzzy set theory, this paper presents a new kind of state controller to eliminate the steady state error, compensate the nonlinearity and have excellent robustness. (5 pages)Development of genetic-PI based controller for interior permanent magnet synchronous motor drive over wide speed range
http://dl-live.theiet.org/content/conferences/10.1049/cp_20060118
This paper develops a genetic-PI based controller for interior permanent magnet synchronous motor (IPMSM) drive. An artificial neural network (ANN) is used for on-line tuning of the PI controller. Genetic algorithm (GA) has been used in this work in order to obtain the optimized values of the PI controller parameters for precise speed control under different operating conditions over wide speed range. The performance index which has been utilized as GA objective function is zero steady-state error, minimum speed deviation, and minimum settling time of the IPMSM drive. The optimal behavior of drive can be achieved by considering two control strategics: maximum torque per ampere (MTPA) control strategy in constant torque region and flux-weakening control strategy in constant power region. In developing the proposed controller, the PI controller parameters are optimized by GA at all operating conditions, in a closed loop vector control scheme. By obtaining the parameters at a number of points in the possible operating region, a look-up table approach has been completed. Then an ANN is trained by this look-up table. Ultimately, the well-trained ANN is utilized for on-line tuning of the PI controller parameters to ensure optimum drive performance under different disturbances and operating conditions over wide speed range.Study on speed-sensorless vector control transducer based on DSP
http://dl-live.theiet.org/content/conferences/10.1049/cp_20061148
In order to improve reliability and adaptability of control system for induction motors, a speed-sensorless vector control transducer based on DSP is presented. The principle of speed-sensorless vector control system is firstly introduced. The mathematic model of the three-phase induction motor is multi-variable, non-linear and strong-coupling, which are uncoupled by coordinate conversion. The detected two phase currents of the three-phase induction motor are imported to an adaptive voltage-model rotor flux estimator. PI self-adaptive algorithm is used to estimate the speed of the induction motor. By comparing the estimated-speed and the command-speed, the adjustment instructions are generated, which control the speed by space vector pulse width modulation (SVPWM). In this paper, the hardware and software structures of speed-sensorless vector control transducer based on DSP are discussed in detail. The key parameters are confirmed by simulations based on Matlab/Simulink. Finally, the designed scheme is demonstrated feasible and effective by the experiments.Adaptive control of linear velocity and tension in winding system of dry plastic film
http://dl-live.theiet.org/content/conferences/10.1049/cp_20061081
Based on the control principle of the dry plastic film laminating machine, and the linear velocity synchronization and variable tension control in the winding process for the two-layer film laminating machinery, this paper presents the system modeling and a new winding drive system using an AC torque motor. Due to the wide range variation of the web radius, the set point of the film tension needs to be changed during the winding process. The tension algorithm is shown to render the control more robust to the radius variations, and the operating voltage of the torque motor is adjusted according to the set point of the linear velocity and the film tension. This makes the mechanical property of the AC torque motor favorable to the winding system, for the adaptive control of linear velocity and tension. The controller chooses a high-speed micro-controller and SCR as its core components. From the applications on the 600 mm and 1000 mm width dry plastic film laminating machine, it is confirmed that this adaptive control system shows a satisfactory performance.An improved servo control system for high speed flat industrial sewing machine
http://dl-live.theiet.org/content/conferences/10.1049/cp_20061077
This paper presents a permanent magnet synchronous motor (PMSM) servo drive system for high speed flat industrial sewing machine. In order to satisfy the special function of sewing machine, several approaches are applied in this servo system: using voltage feed-forward decoupling control in current loop to improve speed and position control performance; variable gain control is adopted in system to compensate incomplete decoupling caused by disturbance and inaccuracy of parameter; PMSM used in system is specially designed with concentrated winding and lean charge magnetism barrel-drain rotor, which can effectually improve motor operating and reduce torque harmonics. The experimental curves of sewing procedure show that: the speed feedback can accurately track speed reference under different sewing conditions, which proof the servo control system meet purpose of industrial sewing machines well.A new approach for speed control of a DC motor fed from AC to DC sepic converter
http://dl-live.theiet.org/content/conferences/10.1049/cp_20051219
A complete modeling and numerical simulation of a system comprising a separately excited DC motor fed from a single-phase, single-way rectifier are presented in this paper. The strategy of this approach is based on the cascade combination of a diode bridge rectifier and a sepic (single-ended primary inductance converter) circuit. Both step-up and step-down characteristics of the output voltage can be obtained. The supply current is approximately sinusoidal and its power factor is high. A good performance is achieved with a simple control circuit and only one switch for the converter. Differential equations describing the system behavior in different modes of operations are presented. Solving these equations enable the predication of the motor performance in both transient and stead-state conditions. The total harmonic distortion of the supply and motor currents are obtained using the numerical simulation of this system. Moreover, the effect of the duty ratio of the converter on the system performance is investigated. The experimental and simulation results confirm the theoretical analysis. The proposed configuration provides a useful rectifier with sinusoidal input current and a satisfactory motor speed regulation. (5 pages)Improved tracking control of industrial servo-drive system by saw torque feedback
http://dl-live.theiet.org/content/conferences/10.1049/cp_20040414
This paper provides a comparative, systematic analysis of conventional and nonconventional velocity control algorithms for a two-inertia mechanical system. The assessment criterion is based on the integral of time multiplied by absolute error performance index, normalized its it function of the mechanical parameters, allowing it direct comparison between simple proportional-integral and more complex control schemes. Tuning, methods for extended control structures are presented and performances evaluated using the dynamics of a commonly employed proportional-integral controller as a benchmark for assessment. It has been shown that the required controller complexity to provide good performance is directly related the mechanical system parameters and is most critical when the load inertia is smaller than that of the motor. Extended structures incorporating a torque feedback signal derived from a low cost, surface acoustic wave transducer are presented and shown to significantly improve the tracking performance of the classical proportional-integral controller. (6 pages)Speed and torque control of switched reluctance motors
http://dl-live.theiet.org/content/conferences/10.1049/cp_20040266
This paper shows two methods of controlling rotational speed and torque of switched reluctance motors. Both methods are based on feedback linearization. The first shows feedback linearization for rotational speed of the drive and the second shows feedback linearization for the generated torque using a modified state space model of the drive. With the modified state space model the generated torque of the drive can be represented by a first order transfer function. Simulation results with help of MATLAB/SIMULINK will be shown in the paper. (6 pages)New variable speed integrated generator for stand alone and support power generation
http://dl-live.theiet.org/content/conferences/10.1049/cp_20040416
This paper is to present a novel type of variable speed power generating system that can be implemented to supply electrical loads in the range of 5 kVA up to 100 kVA. The variable-speed-integrated-generator (VSIG) set consists of a diesel engine, an axial type permanent magnet generator and high frequency power converter. The unique feature of the control system based on a robust digital signal processor (DSP) platform with accurate mapping of engine performance characteristic. The controller is optimised for rapid system response to load application and load demand. The high quality sinusoidal output voltage from VSIG set under various load types and conditions will be presented in this paper. (5 pages)A sensorless speed control using stator ripple currents for an induction motor drive with space phasor PWM
http://dl-live.theiet.org/content/conferences/10.1049/cp_20040263
In the present paper a simple sensorless speed estimation scheme is presented, where the speed information is obtained from the motor phase current ripple. The scheme measures the stator current phasor deviation direction to determine the back EMF vector position during inverter zero vector switching states. This measurement of rotor flux position is done indirectly by computing the motor back EMF position which is orthogonal to the rotor flux position. The space vector PWM voltage output in motor phase generates a current ripple pattern, which depends upon the ripple voltage and equivalent stator leakage inductance. For high speed operation when the time duration for the zero vector switching states are small an indirect method for flux position estimation is proposed, where the effect of active voltage vectors on the stator ripple current is eliminated by creating a virtual short circuit at the motor terminals. (6 pages)Utilization development of speed sensor-less vector controlled inverter with the novel automatic tuning scheme of the induction motor parameters
http://dl-live.theiet.org/content/conferences/10.1049/cp_20040262
This paper presents a feasible development on a highly accurate quick response adjustable speed drive implementation for general purpose induction motor which operates on the basis of sensor-less slip frequency type vector controlled sine-wave PWM inverter with an automatic tuning machine parameter estimation schemes. As the Conclusion, the dynamic speed response performances for largely changed load torque disturbances as well as steady state speed vs. torque characteristics of this induction motor control implementation are illustrated and discussed from an experimental point of view. (8 pages)Sensorless torque vector speed control of a brushless DC motor
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020169
The research described in this paper was intended to evaluate a minimal-computation sensorless control technique for brushless DC motors. The motor used in the research was a cylindrical machine with surface magnets and air-gap windings. Torque vector control is a computationally economical technique for applying torque and flux control loops to electric motors. In the research described, a digital signal processor (DSP) was used to carry out position estimation and control torque and flux by controlling the drive signals to a conventional three-phase, six-switch IGBT inverter The torque vector concept operates by calculation based on a 2-phase equivalent circuit, producing values of flux magnitude and angle and torque. The torque vector control scheme demonstrated a capability for high bandwidth control, as a sampling time of only 2 μs for the inner (torque/flux) loop was achieved with a DSP which had a 50 ns single cycle execution time. The inverter switching frequency is also minimised by the strategy used.A synchronised multi-motor control system using sensorless induction motor drives
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020086
This paper outlines a high-performance induction motor sensorless control strategy engineered for high speed holding accuracy. The strategy utilises a model-based method, tuned by a speed estimate derived from rotor slot harmonic effects seen in stator quantities. Two 4 kW machines, both running the developed scheme, are speed synchronised using a bi-axial cross-coupled control method. Results are shown to be comparable to those obtained from the same synchronisation scheme, and on the same rig, using encoded indirect rotor flux oriented (IRFO) control.Permanent magnet generator options for the More Electric Aircraft
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020121
This study has shown that a permanent magnet generator coupled with a PWM voltage source converter will adequately meet the LP shaft generator requirements for a future More Electric Aircraft. It also adequately satisfies the requirements for wide speed range control and fault tolerance, although it should be noted that full fault tolerance only seems achievable with a direct drive (nongeared) generator. The direct drive machine is suitable for either oil or air cooling, the oil-cooled option being smaller and lighter, even after taking into account the additional converter and cable weight arising from its increased reactance. The geared machine offers a net weight saving of 16% (compared with oil-cooled direct drive) but its fault tolerance is limited to open circuit faults and loss of drive in the power converter only. The study has firmly established the feasibility of permanent magnet generators for the More Electric Aircraft; however further work is required, most notably the estimation of rotor stray loss and the study of power system stability and protection.Adaptive fuzzy logic control of PM brushless AC drives
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020091
The relative merits of PI and fuzzy logic speed control algorithms for a vector-controlled PM brushless AC drive system are assessed. An adaptive fuzzy logic control algorithm with dynamically adjusted membership function of the output fuzzy sets is proposed. Its implementation is very simple, and it offers excellent speed control performance and robustness to parameter variations, whilst current harmonics are reduced.Full-digital predictive hysteresis current control for switching losses minimisation in PMSM drives
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020090
In this paper a novel hysteresis current control is proposed It is based on a simplified predictive algorithm that somewhat recalls those used in the direct torque control drives. The two major features are the sensible reduction of inverter switches commutations and the full-digital implementation based on look-up tables. The proposed algorithm has been implemented as inner loop of a speed control for a permanent magnet synchronous motor (PMSM). The result has been a low-cost, efficient and reliable PMSM drive, with good overall dynamic performance. The paper reports both simulation and experimental results, carried out on a laboratory prototype.Speed, flux and torque estimation of induction motor drives with adaptive system model
http://dl-live.theiet.org/content/conferences/10.1049/cp_20020167
This paper deals with the sensorless speed control of induction motor drives. A model for speed, flux and torque estimation is proposed. Its structure is based on the extended Kalman filter theory. Experimental results are presented on a 1.5 kW induction motor drive to demonstrate the excellent system performance.