To see the other types of publications on this topic, follow the link: Induction motors.
Dissertations / Theses on the topic 'Induction motors'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Induction motors.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Zhang, Wei. "Advanced control of induction motors." Thesis, University of Liverpool, 2013. http://livrepository.liverpool.ac.uk/15033/.
Full textAbstract:
The current industrial standard for the control of the induction motor is the so called vector control (VC) or field-orientated control (FOC) which transforms and controls the induction motor as a direct current (DC) motor. Besides its many advantages, such as fast and decoupled dynamics of speed and flux, it is well known that VC depends on the detailed system model and is very sensitive to parameter uncertainties and external disturbance (load torque). To clarify further the VC is a only a partial feedback linearising control which can achieve the decoupling of speed and flux asymptotically. The coupling still exists when flux is not kept in constant, i.e. when flux is weakened in order to operate the motor at a higher speed and keep the input voltage within saturation limits, or when flux is adjusted to maximize power efficiency of the motor with light load. The thesis will summarise research of advanced control approaches of induction motors in Chapter One. The Chapter Two starts on building a fifth-order nonlinear dynamic model of an induction motor and then recalls the principal of traditional VC of induction motors. The differential-geometric technique based nonlinear control has developed for induction motors, which can convert some intractable nonlinear problems into simpler problems by familiar linear system methods. The partial decoupled dynamic of the conventional VC has been investigated via feedback linearisation control (FLC) at first. Then input-output linearisation control is applied to design a fully decoupled control of the dynamics of speed and flux. To remove the weak robustness and the requirement of an accurate model of the VC and FLC, a novel nonlinear adaptive control of induction motor is designed based on feedback linearisation control and perturbation estimation. The induction motor will be represented as a two coupled interconnected subsystems: rotor speed subsystem and rotor flux subsystem, respectively. System perturbation terms are defined to include the lumped term of system nonlinearities, uncertainties, and interactions between subsystems and are represented as a fictitious state in the state equations. Then perturbations are estimated by designing perturbation observers and the estimated perturbations are employed to cancel the real system perturbations, assumed all internal states are measured. The designed nonlinear adaptive control doesn’t require the accurate model of the induction motor and has a simpler algorithm. It can fully decouple the regulation of rotor speed and rotor flux and handle time-varying uncertainties. The parameter estimations based on nonlinear adaptive controls can only deal with unknown constant parameters and are not suitable for handling fast time-varying and functional uncertainties. Nonlinear adaptive control based on output measurements is addressed in Chapter Five, assuming that the rotor speed and the stator volatge/currents are measurable. A sliding mode rotor flux observer has been designed based on the stator voltage and current. Moreover, two third-order state and perturbation observers are designed to estimate the unmeasured states and perturbation, based on the rotor speed and the estimated rotor flux. Simulation studies have been carried out for verifying the effectiveness of the proposed advanced controllers and compared with the conventional VC and model based FLC.
2
Izguden, Mustafa. "Design Software Development For Induction Motors." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613229/index.pdf.
Full textAbstract:
The purpose of this thesis has been to convert two softwares called TPCAD (Three Phase Induction Machine Computer Aided Desing) and SPCAD (Single Phase Induction Machine Computer Aided Design) developed earlier for the design and analysis of three and single phase induction machines to meet the needs of motor manufacturing industry so that they can be run in windows environment. Furthermore, it was aimed to include features such as double cage motor analysis and design, to provide a facility designed motor lamination can be drawn for the user to see and facilitate sharing the designed lamination with other professional programs such as finite element analysis or thermal analysis etc.
As a result of this study, a user friendly design tool facilitating the design process of induction motors has been upgraded by using C++ Microsoft Visual Studio .Net programming language. TPCAD and SPCAD are tested with different commercial motors. The results show that the full load performance calculations are within the range of 5% error for both programs. However, starting performance calculation errors are within 10% for TPCAD, and 8% for SPCAD.
3
Zhang, Zaining. "Sensorless vector control for induction motors." Thesis, University of Sussex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340849.
Full text
4
Arkan, Muslum. "Stator fault diagnosis in induction motors." Thesis, University of Sussex, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310244.
Full text
5
Sevinc, Ata. "Speed sensorless control of induction motors." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364962.
Full text
6
Wijesundera, Dhammika Sarath. "Microprocessor-based controllers for induction motors." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303258.
Full text
7
Begg, Michael Colin. "Finite element analysis of induction motors." Thesis, Imperial College London, 1986. http://hdl.handle.net/10044/1/37942.
Full text
8
McClay, Catherine I. "Efficiency improvement of cage induction motors." Thesis, University of Cambridge, 1996. https://www.repository.cam.ac.uk/handle/1810/272668.
Full text
9
Karacan, Cuneyt. "Comparison Of Performance Of Switched Reluctance Motors, Induction Motors And Permanent Magnet Dc Motors." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12604925/index.pdf.
Full textAbstract:
Since most of the electrical energy is consumed by the electrical motors, it is necessary to use the electrical energy as efficient as possible.
Throughout this study four different types of motors (induction motor, permanent magnet radial flux DC motor, permanent magnet axial flux DC motor, switched reluctance motor) are considered and compared based on their torque per unit volume and speed performance comparison. Torque per unit volume equations are obtained for each of the motor, related to quantities such as magnetic flux density and electric loading and the speed performances are compared by using a washing machine application, which has a wide speed range.
As a result of this study torque per unit volume and speed performance of each of these four types of motors are obtained and motors of different types are evaluated due to their torque per motor volume, torque per ampere, efficiency and etc. over a wide speed range to have an idea about the applications of these motors.
10
Zhang, Pinjia. "Active thermal protection for induction motors fed by motor control devices." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34811.
Full textAbstract:
Induction motors are widely used in industrial processes. The malfunction of a motor may not only lead to high repair costs, but also cause immense financial losses due to unexpected process downtime. Since thermal overload is one of the major root causes of stator winding insulation failure, an accurate and reliable monitoring of the stator winding temperature is crucial to increase the mean time to catastrophic motor breakdown, and to reduce the extraordinary financial losses due to unexpected process downtime.
To provide a reliable thermal protection for induction motors fed by motor control devices, a dc signal-injection method is proposed for in-service induction motors fed by soft-starter and variable-frequency drives. The stator winding temperature can be monitored based on the estimated stator winding resistance using the dc model of induction motors. In addition, a cooling capability monitoring technique is proposed to monitor the cooling capability of induction motors and to warn the user for proactive inspection and maintenance in the case of cooling capability deterioration. The proposed cooling capability monitoring technique, combined with the proposed stator winding temperature monitoring technique, can provide a complete thermal protection for in-service induction motors fed by motor control devices.
Aside from online thermal protection during a motor's normal operation, the thermal protection of de-energized motors is also essential to prolong a motor's lifetime. Moisture condensation is one of the major causes to motor degradation especially in high-humidity environments. To prevent moisture condensation, a non-intrusive motor heating technique is proposed by injecting currents into the motor stator winding using soft-starters. A motor's temperature can be kept above the ambient temperature due to the heat dissipation, so that the moisture condensation can be avoided.
To sum up, active stator winding temperature estimation techniques for induction motors under both operating and de-energization conditions are proposed in this dissertation for both thermal protection and optimizing the operation of a motor system. The importance of these proposed techniques lies in their non-intrusive nature: only the existing hardware in a motor control device is required for implementation; a motor's normal operation is not interrupted.
11
Khiyo, Sargon. "Neuro/fuzzy speed control of induction motors." Thesis, View thesis, 2002. http://handle.uws.edu.au:8081/1959.7/554.
Full textAbstract:
The thesis involved the design, implementation and testing of a second order neuro-fuzzy controller for the speed control of an AC induction motor, and a comparison of the neuro-fuzzy controller's performance with that of the PI algorithm. It was found experimentally, that the operating temperature of the AC induction motor affected the ability of the PI controller to maintain the set speed. The linear PI algorithm approximation was observed to produce transient speed responses when sudden changes in load occurred. The neuro-fuzzy design was found to be quite involved in the initial design stages. However, after the initial design, it was a simple matter of fine-tuning the algorithm, to optimize performance for any parameter variations of the motor due to temperature or due to sudden changes in load. The neuro-fuzzy algorithm can be developed utilising one of two methods. The first method utilises sensor-less control by detailed modeling of the induction motor; where all varying parameters of the motor are modeled mathematically. This involves using differential equations, and representing them in the form of system response block diagrams. When the overall plant transfer function is known, a fuzzy PI algorithm can be utilised to control the processes of the plant. The second method involves modeling the overall output response as a second order system. Raw data can then be generated in a text file format, providing control data according to the modeled second order system. Using the raw data, development software such as FuzzyTECH is utilised to perform supervised learning, so to produce the knowledge base for the overall system. This method was utilised in this thesis and compared to the conventional PI algorithm. The neuro-fuzzy algorithm implemented on a PLC was found to provide better performance than the PI algorithm implemented on the same PLC. It provided also in the added flexibility for further fine-tuning and avoided the need for rigorous mathematical manipulation of linear equations
12
Adams, Nicholas K. "Power-factor improvement in cage induction motors." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38210.
Full text
13
Khiyo, Sargon, University of Western Sydney, of Science Technology and Environment College, and School of Engineering and Industrial Design. "Neuro/fuzzy speed control of induction motors." THESIS_CSTE_EID_Khiyo_S.xml, 2002. http://handle.uws.edu.au:8081/1959.7/554.
Full textAbstract:
The thesis involved the design, implementation and testing of a second order neuro-fuzzy controller for the speed control of an AC induction motor, and a comparison of the neuro-fuzzy controller's performance with that of the PI algorithm. It was found experimentally, that the operating temperature of the AC induction motor affected the ability of the PI controller to maintain the set speed. The linear PI algorithm approximation was observed to produce transient speed responses when sudden changes in load occurred. The neuro-fuzzy design was found to be quite involved in the initial design stages. However, after the initial design, it was a simple matter of fine-tuning the algorithm, to optimize performance for any parameter variations of the motor due to temperature or due to sudden changes in load. The neuro-fuzzy algorithm can be developed utilising one of two methods. The first method utilises sensor-less control by detailed modeling of the induction motor; where all varying parameters of the motor are modeled mathematically. This involves using differential equations, and representing them in the form of system response block diagrams. When the overall plant transfer function is known, a fuzzy PI algorithm can be utilised to control the processes of the plant. The second method involves modeling the overall output response as a second order system. Raw data can then be generated in a text file format, providing control data according to the modeled second order system. Using the raw data, development software such as FuzzyTECH is utilised to perform supervised learning, so to produce the knowledge base for the overall system. This method was utilised in this thesis and compared to the conventional PI algorithm. The neuro-fuzzy algorithm implemented on a PLC was found to provide better performance than the PI algorithm implemented on the same PLC. It provided also in the added flexibility for further fine-tuning and avoided the need for rigorous mathematical manipulation of linear equationsMaster of Engineering (Hons)
14
Wong, D. "Speed control of three-phase induction motors." Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376194.
Full text
15
Poh, Chze Y. "Inter-bar currents in cage induction motors." Thesis, University of Manchester, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.679961.
Full text
16
Lüdtke, Ingo. "The direct torque control of induction motors." Thesis, University of South Wales, 1998. https://pure.southwales.ac.uk/en/studentthesis/the-direct-torque-control-of-induction-motors(5b85e666-04b6-493b-b615-c5e2144d03c6).html.
Full textAbstract:
This thesis is mainly devoted to the investigation of speed control methods of three phase, cage rotor induction motors with particular emphasis being given to vector control and direct torque control techniques. Modern control strategies such as vector control and direct torque control are investigated as well as the conventional methods such as open loop (constant V/f) operation. A number of different pulse width modulation (p.w.m.) waveform generation strategies are simulated and discussed and their application to the above speed control systems fully investigated. A 3kW, three phase induction motor drive has been designed and experimental data obtained from it in order to verify the results achieved by simulation. It is shown that direct torque control achieves decoupling of the motor torque and the motor flux without the use of a co-ordinate transform. A variation of the direct torque control algorithm has also been developed and implemented. It is shown, that by using different switching tables for the selection of voltage vectors, the performance of direct torque control can be further improved. Further insight into the nature of direct torque control has been gained from the study of the effect of the application of inverter switch settings, or the application of corresponding voltage vectors, on the motor flux and torque. It has been found that the range of torque variation of the motor drive system depends strongly on both the motor load torque and the motor speed. The results of the work reported indicate that the range of torque variation for a drive system which strongly depends on motor load torque and motor speed is considerably reduced by the novel direct torque control system resulting from the research. The control algorithms have been implemented on 32 bit micro processors which facilitate the use of parallelism in both the hardware and the software design. The resulting system is capable of controlling a three phase induction motor with variable voltage and variable frequency with control strategies such as six step operation, symmetric and asymmetric regular and natural sampled p.w.m. waveforms, sigma delta modulation methods, space vector modulation techniques, flux vector control and direct torque control.
17
van, der Toorn Gregory Theo. "Investigation of losses in cage induction motors." Thesis, University of Cambridge, 2001. https://www.repository.cam.ac.uk/handle/1810/272003.
Full text
18
Khiyo, Sargon. "Neuro/fuzzy speed control of induction motors /." View thesis, 2002. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030925.144725/index.html.
Full textAbstract:
Thesis (M. E. (Hons))--University of Western Sydney, 2002."A thesis submitted for Master of Engineering (Honours), School of Engineering & Industrial Design, University of Western Sydney, October 2002" Bibliography: leaves 147 - 149.
19
Göl, Özdemir. "Dynamic modelling of induction machines /." Title page, contents and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phg595.pdf.
Full text
20
Deib, Deib Ali. "Induction motor operation with series capacitance." Ohio : Ohio University, 1986. http://www.ohiolink.edu/etd/view.cgi?ohiou1183129403.
Full text
21
Arias, Pujol Antoni. "Improvements in direct torque control of induction motors." Doctoral thesis, Universitat Politècnica de Catalunya, 2001. http://hdl.handle.net/10803/6317.
Full textAbstract:
This thesis is mainly devoted to the investigation of speed control methods for three phase cage induction motors with particular emphasis being given to Direct Torque Control (DTC) improved techniques.Classical Direct Torque Control has inherent disadvantages such as: problems during starting resulting from the null states, the compulsory requirement of torque and flux estimators, and torque ripple. In the classical DTC induction motor drive a voltage vector is applied for the entire period, and this causes the stator current and electromagnetic torque exceeds its reference value early during the cycle, causing a high torque ripple. Switching cycles then follows this, in which the zero switching vectors are applied in order to reduce the electromagnetic torque to reference value. This thesis suggests a technique based on applying to the inverter the selected active states just enough time to achieve the torque and flux references values. The rest of the switching period a null state is selected which won't almost change both the torque and the flux. Therefore, a duty ratio has to be determined each switching time. By means of varying the duty ratio between its extreme values (0 up to 1) it is possible to apply any voltage to the motor. The optimum duty ratio per sampling period is a non-linear function of the electromagnetic torque error, the stator flux position and the working point, which is determined by the motor speed and the electromagnetic torque. It is obvious that it is extremely difficult to model such an expression since it is a different non-linear function per working point. Therefore, this thesis is focused on performing a fuzzy-logic-based duty-ratio controller, where the optimum duty ratio is determined every switching period. Additionally, this Fuzzy Controller is adaptive and may be applied to any induction motor.
A stator flux reference optimum controller is also designed, which not only helps to achieve a smaller torque ripple, but also reduces the reactive power consumption of the drive taken from the main supply. This is achieved by changing the stator flux reference value with reference being made to the correspondent torque reference value. Therefore, the stator flux reference value chosen is to be just of sufficient value to produce the desired torque
Simulated results are shown in order to compare the classical DTC and the Fuzzy Logic based DTC.
The control algorithms have been implemented on a PC/DSP based board that facilitates the use of parallelism in software design. A 1.5kW, three-phase induction motor drive has been designed and experimental data obtained from it in order to verify the results achieved by simulation.
22
Govindsamy, Matthew. "Sensorless speed estimation in three phase induction motors." Thesis, Port Elizabeth Technikon, 2002. http://hdl.handle.net/10948/139.
Full textAbstract:
This thesis proposes a technique to determine and improve the performance of a sensorless speed estimator for an induction motor based on Motor Current Signature Analysis (MCSA). The theoretical concepts underlying the parameter based observer are developed first and then the model of the observer is built using Simulink. The observer is developed based on Model Reference Adaptive System (MRAS). The dynamic performance of the observer and its behavior due to variation of machine parameters is studied. The error in speed estimated using this observer is shown and the ability of MCSA to retune the rotor speed from the stator current spectrum. The spectrum estimation technique has been implemented using a software routine in Matlab. Both the observer and MCSA techniques were implemented practically on an induction motor. The performance of the combined sensorless speed estimation system was tested and verified.
23
Wang, Chong Aerospace & Mechanical Engineering Australian Defence Force Academy UNSW. "Vibro-acoustic analysis of inverter driven induction motors." Awarded by:University of New South Wales - Australian Defence Force Academy. School of Aerospace and Mechanical Engineering, 1998. http://handle.unsw.edu.au/1959.4/38706.
Full textAbstract:
With the advent of power electronics, inverter-driven induction motor are finding increased use in industries because of applications that demand variable speed operations and because of the potential savings in energy usage. However, these drives sometimes produce unacceptably high levels in vibration and acoustic noise. A literature survey has revealed that while there has been intensive research on the design of inverters to minimize acoustic noise radiation from these drives, the vibro-acoustic behaviour of an induction motor structure has received relatively little attention. The primary objective of this research project, therefore, is to develop a general strategy/algorithm for estimating the acoustic noise radiated from inverter-driven induction motors. By using a three-phase, 2.2 kW induction motor, the vibration modes due to various structural components (such as the rotor, the stator/casing, the endshields and the base plate) of the motor structure were analysed by experimental modal testing. Results indicate that the vibration modes due to the rotor are only important at low frequencies. It has been found that the power injection method gives more accurate measurement of the damping of a motor structure than the modal testing and the time decay methods. If a point force excitation is used, then it is more accurate to measure the sound radiation efficiency than the power conversion efficiency for motor structures. The effect of three different inverter designs (an ideal ???almost sinusoidal??? controller and two commercially available PWM inverters) on the radiated acoustic power were assessed for both no-load and load conditions using sound intensity measurements conducted in an anechoic room. The results indicate that although the sound power level due to aerodynamic and mechanical noise increases at a rate of 12 dB per doubling of the motor speed, the electromagnetic noise dominates at low motor speeds and is still a significant noise source even at high motor speeds. For inverters with low switching frequencies, the radiated sound power level is almost 15 dB higher than the ideal case at low speeds and is relatively insensitive to the motor speed. For inverters that implement the random modulation technique, the change in the total sound power level with the level of the random modulation is very small but the tonal nature of the noise is greatly reduced. The vibration behaviour of a motor structure was modeled using the finite element method (FEM) and validated using the experimental modal testing results. It has been found that it is essential to model the laminated stator as an orthotropic structure. While the details of other structural components (such as the endshields, the teeth in the stator and the windings) are not so important, it is essential that they are incorporated into the structural model as simplified structures to account for their mass, stiffness and boundary conditions imposed on the motor structure. Based on this structural model, the radiated acoustic power for various operating conditions has been predicated using the boundary element (BEM) and the electromagnetic force calculated from an electromagnetic finite element model. The predicted results agree reasonably well with experimental measurements. Despite the success of the FEM/BEM approaches, they can be prohibitively expensive (in terms of computer resources required) to apply to large motors and high frequencies. Thus the feasibility of using a statistical method, namely, the statistical energy analysis (SEA), to estimate the radiated acoustic sound power from an inverter-driven induction motor has been examined. In order to carry out this analysis, analytical expressions for calculating the natural frequencies and radiation efficiency of finite length circular cylindrical shells (which are simplified models of the stator and casing of a motor structure) were firstly derived. The internal loss factors and coupling loss factors of the motor structure were determined experimentally using the power injection method. Then by introducing an equivalent surface mobility of circular cylindrical shells for the electromagnetic force, the vibration response and the acoustic noise radiated from each part of the motor structure were estimated. Results indicate that SEA method is potentially an efficient and effective tool in estimating the noise radiated from inverter-driven induction motors.
24
Idir, Kamel. "Optimization and neural network model for induction motors." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0020/NQ46293.pdf.
Full text
25
Curley, Andrew J. "Cage induction motors with end-region conducting discs." Thesis, Imperial College London, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284562.
Full text
26
Dawe, Roger Michael. "Digitally controlled soft-starting of cage induction motors." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277301.
Full text
27
del, Toro GarciÌa Xavier. "Improvements in direct torque control of induction motors." Thesis, University of South Wales, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446106.
Full text
28
Ismail, K. S. "Speed-changing of induction motors by phase modulation." Thesis, University of Bristol, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232792.
Full text
29
Leonard, P. J. "Design and analysis of tubular linear induction motors." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37759.
Full text
30
Mushenya, John. "Energy efficiency analysis of converter-fed induction motors." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29301.
Full textAbstract:
Electric motor systems are the largest consumers of industrial electrical energy. As Variable Speed Drives continue to dominate various industrial processes, there is need for stakeholders to fully understand and quantify the converter-fed motor losses over a wide range of operating conditions. Such knowledge is crucial for both manufacturers and end-users in performing energy-efficiency optimizations for motor-drive applications. Although there is an increase in legislative activities, particularly in Europe, toward classification and improvement of energy efficiency of electric motor-drive systems, the available standards for quantifying the various losses are still in their early stages of development. None of these standards have yet passed through all the required phases for them to be considered full international standards, owing to a lack of consensus on many technical issues. Therefore, the need for researchers to provide feedback to the relevant standards committees cannot be over-emphasized. One of the most challenging issues in estimating the efficiency of converter-fed motors is the accurate determination of additional harmonic losses due to the PWM voltages and currents. Although the recently introduced IEC 60034-2-3 Technical Specification has proposed a method of determining these losses through experimental testing, the approach is still undergoing validation. Moreover, it only considers the rated motor frequency and voltage whereas induction motor drives are usually operated over a wide range of speed and torque. The main emphasis of the work presented in this dissertation was to develop a thorough understanding of various converter-fed induction motor losses, and hence efficiency, when fed from a 2-level Voltage Source Inverter. In particular, the dissertation provides a healthy questioning of some concepts in the proposed IEC method, with a view to providing useful feedback for improving the standard. Comparisons are also drawn between the related standards to identify areas for improvement. This study further attempts to explain some conflicting reports cited in literature regarding the nature of additional harmonic losses. The experimental results obtained by testing three induction motors demonstrate some of the technical issues associated with the determination of additional harmonic losses. To mitigate the adverse effect of varying technical skill and competence levels on efficiency test results, an automated testing procedure was developed and implemented on the 110kW test rig in the UCT Machines Lab. The test rig, which boasts of a Genesis 7i high-speed Data Acquisition System, also provides an energy-efficient platform for investigating the steadystate and dynamic characteristics of converter-fed motors. By utilizing the capability of the Data Acquisition System to segregate the fundamental and harmonic components of measured input electrical power, it was found that a PWM power supply can be used in place of a conventional Variac to estimate the sinusoidal supply efficiency of an induction motor. This is a welcome development for both laboratory and field efficiency testing applications.
31
Jin, Changxi. "Sliding mode control and estimation of induction motors." Connect to resource, 1997. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1157659298.
Full text
32
Evangelista, Dennis J. (Dennis Jose) 1977. "Parameter estimation of induction motors using PWM inverters." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9457.
Full textAbstract:
Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 197-200).
Induction motor parameter identification algorithms utilizing the DSP controlled 3 phase PWM inverter constructed in [12] are discussed. A single stator voltage test is carried out with the machine's rotor standing still. The resulting transient is used to determine machine electrical parameters. Several algorithms for this are discussed, extending work discussed in [21], (34], and (35]. The final algorithm tested uses a radial basis function network to approximate a function mapping from a time lag space consisting of the dq transformed stator currents to a space of machine electrical parameters. This algorithm is attractive because it is very easy to perform, consisting of one nonlinear step and one linear step. The original goal for the hardware of [12] was to perform adaptive field-oriented control on small induction motors. Several observers and online flux estimation methods, as well as alternative algorithms including neural networks and genetic algorithms, were looked at over the course of this year. This background is provided in the appendix, in order to aid future work on this project.
by Dennis J. Evangelista.
S.B.and M.Eng.
33
Riehl, Rudolf Ribeiro. "Uma metodologia para determinação das capacitâncias parasitas de motores de indução trifásicos de rotor em gaiola." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260738.
Full textAbstract:
Orientador: Ernesto Ruppeert FilhoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-16T04:00:35Z (GMT). No. of bitstreams: 1 Riehl_RudolfRibeiro_D.pdf: 5043112 bytes, checksum: b6091e6e6b5591d8885535a13baae465 (MD5) Previous issue date: 2010
Resumo: O objetivo deste trabalho é o de apresentar uma nova metodologia para determinação experimental das capacitâncias parasitas do motor de indução trifásico de rotor em gaiola. As capacitâncias parasitas fazem parte do circuito equivalente do motor para estudos de interferência eletromagnética causada no motor de indução em modo comum quando ele for acionado por inversor controlado por modulação por largura de pulsos (MLP). Os procedimentos propostos para o desenvolvimento deste novo método consistem em: a) determinação dos parâmetros do circuito equivalente do motor de indução trifásico, em regime permanente, através de ensaio em laboratório; b) estabelecer configurações de ligações entre o inversor MLP e o motor para medições das grandezas de interesse que são as seguintes: tensões de modo comum e de eixo, correntes de fuga e de eixo, através de circuito de medição desenvolvido para este fim; c) calcular os valores das capacitâncias parasitas entre estator e carcaça do motor; estator e rotor; rotor e carcaça e de rolamento utilizando a expressão matemática da definição de capacitância; d) utilizar o software Pspice para simular o sistema motor de indução trifásico, alimentado por inversor MLP, com os circuitos equivalentes em baixas e altas frequências; e) obter as formas de onda características do fenômeno de modo comum
Abstract: Three-phase induction motors present stray capacitances. The aim of this thesis is to present a new methodology to experimentally determine these capacitances and also evaluates the effects of electromagnetic interference on the motors in common mode. The proposed procedures to the development of this new methodology consists in: a) identification of the motor equivalent electrical circuit parameters through characteristic tests performed in the laboratory; b) to set up configurations between PWM inverter and the motor for voltage and current measurements: common mode and shaft voltages, leakage and shaft (bearing) currents by using a dedicated measuring circuit; c) to calculate the parasitic capacitance values between stator and frame, stator and rotor, rotor and frame and bearings of the motor using the capacitance characteristic equation; d) use the dedicated software Pspice to simulate the system composed by the three-phase induction motor fed by PWM inverter with the equivalent electrical circuit parameters; e) to determine the characteristic waveforms involved in the common mode phenomenon
Doutorado
Energia Eletrica
Doutor em Engenharia Elétrica
34
Bade, Rajesh Kumar. "Analysis of incipient fault signatures in inductive loads energized by a common voltage bus." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3095.
Full textAbstract:
Recent research has demonstrated the use of electrical signature analysis (ESA),
that is, the use of induction motor currents and voltages, for early detection of motor
faults in the form of embedded algorithms. In the event of multiple motors energized
by a common voltage bus, the cost of installing and maintaining fault monitoring and
detection devices on each motor may be avoided, by using bus level aggregate electrical
measurements to assess the health of the entire population of motors. In this research
an approach for detecting commonly encountered induction motor mechanical faults
from bus level aggregate electrical measurements is investigated.
A mechanical fault indicator is computed processing the raw electrical measurements
through a series of signal processing algorithms. Inference of an incipient fault
is made by the percentage relative change of the fault indicator from the ÂhealthyÂ
baseline, thus defining a Fault Indicator Change (FIC).
To investigate the posed research problem, healthy and faulty motors with broken
rotor bar faults are simulated using a detailed transient motor model. The FIC
based on aggregate electrical measurements is studied through simulations of different
motor banks containing the same faulty motor. The degradation in the FIC when
using aggregate measurements, as compared to using individual motor measurements,
is investigated. For a given motor bank configuration, the variation in FIC with
increasing number of faulty motors is also studied. In addition to simulation studies
experimental results from a two-motor setup are analyzed. The FIC and degradation
in the FIC in the case of load eccentricity fault, and a combination of shaft looseness
and bearing damage is studied through staged fault experiments in the laboratory
setup.
In this research, the viability of using bus level aggregate electrical measurements
for detecting incipient faults in motors energized by a common voltage bus is
demonstrated. The proposed approach is limited in that as the power rating fraction
of faulty motors to healthy motors in a given configuration decreases, it becomes far
more difficult to detect the presence of incipient faults at very early stages.
35
Chaudhari, Subodh. "Load based energy savings in three phase squirrel cage induction motors." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3749.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2004.Title from document title page. Document formatted into pages; contains x, 147 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 117-121).
36
Bharadwaj, Aravind S. "Vector controlled induction motor drive systems." Diss., This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06062008-172143/.
Full text
37
Cox, Thomas. "Development of novel linear drive machines." Thesis, University of Bath, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500760.
Full textAbstract:
Linear induction machines currently play a relatively minor role in the industrial world. This is partly due to relatively high production costs, complexity of construction and the Inability to apply standard mass production techniques. The aim of this thesis is to investigate the design of linear machines that are cheaper and faster to produce, and that may easily be mass-produced This thesis principally concerns the use of concentrated winding linear stators. These are cheap and easy to manufacture and can be easily mass-produced. However, high levels of negative harmonics make them unsuitable for use with simple sheet rotors.
38
Stavrou, Andreas. "Analysis and simulation of faults in squirrel cage motors." Thesis, University of Aberdeen, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390266.
Full textAbstract:
Condition based maintenance of electrical machines offers significant advantages for industry. A large part of the research effort in this area is directed towards the evaluation of fault conditions. This thesis is concerned with analysing and modelling faults in induction motors. A method for evaluating the performance of induction machines with static and dynamic eccentricity is developed, using harmonic analysis of the air gap permeance. Models able to simulate eccentricity are presented. The slip ring model equations are obtained and then used to obtain the commutator models transformed to a single reference frame. A variety of effects accompanying these fault conditions are analysed, for example variation of the eccentricity level due to unbalanced magnetic pull and the possibilities of additional vibration harmonics examined. Damping of eccentricity fields due to current redistribution, saturation and slotting are discussed. Some general steady state calculations are also presented which show that the performance of the machine need not be changed over the operating range, due to such a fault. The characteristics of combined static and dynamic eccentricity are examined and it is shown that the combined asymmetry generates additional harmonic components which are not related to those which occur when the two asymmetries take place in isolation. The development of a simulation model of machines with broken rotor bars, based on the variation in rotor parameters is presented. Experimental investigations focus mainly on observable differences in the torque transient characteristics, due to such a condition. The possibilities for using current monitoring to identify inter-turn short circuits are investigated.
39
Comanescu, Mihai. "Flux and speed estimation techniques for sensorless control of induction motors." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1116338965.
Full textAbstract:
Thesis (Ph.D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xv, 109 p.; also includes graphics. Includes bibliographical references (p. 106-109). Available online via OhioLINK's ETD Center
40
Feyzi, Mohammad Reza. "Thermal modelling of deep bar induction motor at stall /." Contents and summary only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phf435.pdf.
Full text
41
Ungku, Amirulddin Ungku Anisa. "Analysis and simulation of vector controlled bearingless induction motors." Thesis, University of Nottingham, 2006. http://eprints.nottingham.ac.uk/14308/.
Full textAbstract:
The concept of bearingless motors, which combine both motoring and rotor bearing capabilities, is appealing especially in high speed and high power machine applications. Although extensive research has been carried out on permanent magnet and reluctance types of bearingless motors, studies on the induction motor type are less successful. This thesis addresses the bearingless induction motor based on the concept of dual-pole windings, one controlling the motor torque and the other the generated radial forces. A modelling approach is undertaken to investigate the effect of induction machine design on radial force generation and motor levitation under both steady state and transient conditions. The simulation is based on the dynamic reluctance mesh model embedded in vector control systems for the decoupled control of torque, flux and radial force. This is achieved through modification of a previously developed computer software for modelling induction motors in order to model the control of bearingless induction motors. Both the squirrel cage and wound rotor induction motors are investigated and their suitability for generating controlled bearing relief forces assessed. Vector control schemes for the bearingless cage and wound rotor induction motors were also designed and simulated. A mixed field oriented vector control scheme, which incorporates the simple rotor field orientation for motoring control and an airgap field orientation for rotor levitation control, is introduced and found to be advantageous in bearingless induction motor control. Apart from investigating totally bearingless conditions, the study also investigates bearing relief capabilities for a vector controlled cage and wound rotor induction motor in which the rotor movement is restricted by bearings but with the bearing load cancelled by suitably directed radial force. The effects of real winding topologies, stator and rotor slotting and iron saturation on the performance of bearing relief and bearingless induction motors are also presented. Finally, suggestions for future work is included In order to further investigate bearingless induction motors and its applications.
42
Bousbaine, Amar. "An investigation into the thermal modelling of induction motors." Thesis, University of Sheffield, 1993. http://etheses.whiterose.ac.uk/1824/.
Full textAbstract:
Electric motors are the ubiquitous workhorses of the industry, working a in wide range of conditions and applications. Modern motors, designed to exact ratings using new materials improved manufacturing techniques, are now much smaller but have higher loadings. They are being operated much nearer to the point of overload then ever before. To ensure a satisfactory life span for the motor, temperature rise must be limited to safe values. A lumped parameter thermal model has been developed, which allows rapid and accurate estimation of the temperature distribution in a machine. The lumped parameter thermal model depends on the accurate knowledge of the thermal coefficients and more importantly the loss distribution. Hence the temperature time technique was implemented to investigate the iron loss density distribution. Experimental results are discussed and loss density information throughout the volume of the machine was generated. A novel method of determining the thermal coefficients employed in the heat flow equation was investigated, using the thermal lumped parameter model of a machine. Finally a 2-D finite element method was used to corroborate, or otherwise, the use of the lumped thermal network model.
43
Calis, Hakan. "Current based detection of mechanical faults in induction motors." Thesis, University of Sussex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300597.
Full text
44
Kneebone, Nigel J. "Efficiency and speed control of three-phase induction motors." Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277167.
Full text
45
王化謙 and Huaqian Wang. "A novel sliding mode control method for induction motor drives." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31234495.
Full text
46
Wang, Huaqian. "A novel sliding mode control method for induction motor drives /." [Hong Kong] : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B15970073.
Full text
47
Bhamidi, Sarveswra Prasad. "Design of a single sided linear induction motor (SLIM) using a user interactive computer program." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4308.
Full textAbstract:
Thesis (M.S.)--University of Missouri-Columbia, 2005.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (May 26, 2006) Includes bibliographical references.
48
Schoen, Randy R. "On-line current-based condition monitoring of three-phase induction machines." Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/12952.
Full text
49
Gersh, Danielle. "Single slot models for cage rotors." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361677.
Full text
50
Perovic, Srdjan. "Diagnosis of pump faults and flow regimes." Thesis, University of Sussex, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288827.
Full text