Polyphase Induction Motors Research Articles

An interior search algorithm based on chaotic and crossover strategies for parameter extraction of polyphase induction machines

The accuracy of the extracted parameters is important for studying the polyphase induction motor performance and/or the motor control schemes. An investigated and improved interior search algorithm (IISA) is presented in this study for extracting the optimal values of estimated parameters of six-phase and three-phase induction motors. This investigation was carried out on two polyphase induction motors as experimental research cases, utilizing features of manufacturer's operation. The estimated parameters show the high capability regarding the performance of the desired IISA optimizer. The performance of the proposed IISA is compared with different modern optimization algorithms including the basic ISA, and other state-of-the-art approaches. Experimental verifications are validated on two polyphase induction motors, called six-phase and three-phase induction motors. The obtained results show that the proposed method is very competitive in extracting the unknown parameters of different induction motor models with a high degree of closeness to the experimental records. Moreover, various statistical tests, such as the Wilcoxon rank test, stability analysis, and convergence analysis, have been conducted to justify the performance of the proposed IISA. From all the analyses, it has been revealed that the proposed IISA is a competitive method compared to other popular state-of-the-art competitors and ISA variant with accurately identified parameters.

Hybrid optimization algorithm for parameter estimation of poly-phase induction motors with experimental verification

The estimated parameters accuracy of poly-phase induction motors is crucial for effective performance prediction and/or control in various manufacturing applications. This study investigates hybrid algorithm between particle swarm optimization and Jaya optimization algorithms for finding the optimal parameters estimation of poly-phase induction motors. It is carried out using the manufacturer's operation characteristics on two poly-phase induction motors. Numerical results show the capability of the proposed hybrid optimization algorithm. The proposed algorithm has competitive performance compared with conventional algorithms as well as with differential evolution and genetic algorithms. Experimental verifications are carried out on three-phase and six-phase induction motors. Also, it emulates the closeness between experimental and estimated parameters with fast convergence compared to other algorithms. Also, the results reflect the high robustness of the proposed algorithm compared with other algorithms for varied iteration numbers, population size and convergence.

Impact of Polyphase Induction Motor on Photovoltaic Water Pumping System

An improved dynamic behavior of water pumping system is presented in this paper. The system consists of a seven-phase induction motor powered by a photovoltaic generator (PVG) and a battery bank, via two static converters controlled independently. A boost converter based on fuzzy logic controller is utilized to adapt the voltage of the photovoltaic generator in order to extract maximum power. A three levels neutral point clamped inverter (NPC) is introduced to attain a low voltage harmonic distortion in the system. In addition, an improved direct field oriented control with minimizing non-sequential currents for the seven-phase induction motor using fuzzy logic filter is implemented. To verify and validate the proposed system, an optimal operating point is chosen to locate the dynamic and static operating limits of the system. Moreover, the proposed system is simulated and analyzed. The minimization of the non-sequential currents component induces a quality energy improvement with minimizing of the Joule losses, which increase the system efficiency. The use of the seven-phase machine brings a degree of additional freedom to the system, its tolerance to faults is a capital issue for the isolated places.

Kinerja Motor Induksi 1-fasa Disain 4 Kumparan dengan Kapasitansi Kapasitor Jalan Terkendali

Single phase induction motor usually has two windings. Because of that, the motor usually operated at lower efficiency than the poly-phase induction motor. A new design had been developed by using poly-phase winding to improve motor efficiency, but characteristic of the current winding at low load condition is not good. So that, this study was aimed to design a 4 phase windings construction of a single phase induction motor that using capacitance control of the run capacitor on auxiliary winding. This design was focused for capacitor-start capacitor-run induction motor that had 4 windings, one winding act as the main winding and the other three windings act as the auxiliary windings. The main and the auxiliary windings current rating of the proposed motor were 2.74A and 3.15A, respectively. The auxiliary winding current of the proposed motor was controlled by the ‘Arduino Uno’ control system. To get the best control system of the proposed motor, the performances of the proposed motor were compared to the performances of a conventional single-phase induction motor that had the same current rating, stator and rotor construction. The single-phase comparator motor used in this study was a conventional single-phase induction motor of 220V, 50 Hz, 1 HP, 8.3A, 4 poles, 1400 RPM cage rotor. The result showed that the proposed motor with capacitance control in auxiliary winding had better performances than the conventional induction motor.

Improved Characterization of Polyphase Induction Motor Losses: Test Standards Must Be Modified to Improve Efficiency Optimization

For many years, industry standards, including IEEE Standard 112, have characterized the component losses of three-phase induction motors as primary and secondary conductor or (I2R) core, friction and windage, and stray load loss (SLL). The definition of each, as epitomized by IEEE 112, guarantees that part of the losses will be characterized as SLL. It also ensures that the secondary I2R loss will be underestimated and that the core loss associated with field distortions resulting from load current are not properly identified. This article provides the opportunity to further optimize motor efficiency by discussing issues with existing test-standard loss models and describing model methods that better characterize motor losses.

Expanded Field Data Analysis in Support of a Torque-Based Motor Bus Transfer Criterion

The ANSI/NEMA C50.41 Standard, “Polyphase Induction Motors for Power Generating Stations” states, “Induction motors are inherently capable of developing transient current and torque considerably in excess of rated current and torque when exposed to out-of-phase bus transfer.” Further, “The magnitude of this transient current and torque may range from 2 to 20 times rated.” This suggests a criterion related to a multiple of rated full load torque. Since a motor bus is comprised of an aggregate of different motors and loads, it is unrealistic to create an industry criterion for measuring the severity of the transfer of the aggregate bus based on individual motor rated torques. Data from several live motor bus transfer events at industrial facilities were analyzed with a new transfer metric based on the ratio of the aggregate peak torque at transfer to the aggregate running torque just before transfer. These torque ratio results were scrutinized based on the C50.41 range from 2 to 20 times rated and then compared with the C50.41 per-unit volts/hertz criterion, calculated at transfer, which is presently used to determine an acceptable transfer. The calculation method is presented with the theory and mathematics employed, and is verified with simulation of a representative induction motor. Analyzing field cases, calculating torque ratio (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PK</sub> /T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> ), and comparing with the per-unit volts/hertz value, demonstrate the validity of this torque ratio metric for determining an acceptable limit for transfer. The periodical version of this paper contains updated material not found in the original conference record edition.

자속밀도와 턴수 자동선정을 활용한 다상 유도전동기 기초 설계 프로세스에 관한 연구

자속밀도와 턴수 자동선정을 활용한 다상 유도전동기 기초 설계 프로세스에 관한 연구

Windings Design for Single-phase Induction Motors Base on 4-phase Induction Motor (Case study: identical windings design)

A 1-phase induction motor usually has a complicated windings design which compares to polyphase induction motor. In addition, a large capacitor start is required to operate the motor. It is an expensive way to operate the motor if it compare to polyphase induction motor. So, a new innovation method is required to make the motor more simple and cheaper. This research is purposed to study a new winding design for a single-phase capacitor motor. Winding design of the motor was conducted to a simple winding design like a 4-phase induction motor that has four identical windings. The comparator motor that use in this study was a Three-phase induction motor with data 1400 RPM, 1.5 HP, 50Hz, 380/220V, Y/Δ, 2.74/4.7A, 4 poles, that had the same current rating which the proposed method. The result showed that the motor design on this proposed method could be operated at 88.18 % power rating with power factor close to unity.

과전류 부하에서 5상 농형 유도전동기의 정수 특성

This paper propose a variable parameter estimations for variable over current load of five-phase squirrel-cage induction motor(IM) to servo control system. In order to high performance control of AC motor using a field oriented control(FOC) and direct torque control(DTC) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, torque command of current components, rotor position, speed estimation, and so on. We are suggest a analyzed estimation results of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental within variable over current load at rated input frequency. There are results of stator winding measurement, no-load test, locked-rotor test, variable over current load test, and estimated parameters of equivalent circuits using manufactured experimental apparatus by IEEE Standard Test Procedure for Polyphase Induction Motors and Generators 112-2004.

Steady – State Performance of Induction and Transfer Field Motors – A Comparison

This paper presents the steady–state performance comparison between polyphase induction motor and polyphase TF motor operating in the asynchronous mode. It is shown graphically that a p-pole TF motor in operation is similar to an induction motor with 2p poles and hence its synchronous speed is limited to one-half (ω/2) of that of an induction motor. Additionally the pull-out torque of TF motor is inferior to that of an induction motor of the same dimensions, being less than ¼ of that of an equivalent induction motor on account of its higher leakage reqactance and in particular, the quadrature axis reactance. http://dx.doi.org/10.4314/njt.v34i2.24

A Novel method of Starting Induction Motor - A Comparative Study

Polyphase induction motor, when started from rest with full voltage impressed, the starting current is 5 to 8 or more times the rated current. The large line current drawn by such a motor is objectionable because of the possible sharp drop in voltage of the supply circuit and undesired effects upon other connected loads/devices. Accordingly it is customary to start such motors at reduced voltage by using auto transformers, star delta starters etc. This paper deals with a new approach to start poly phase induction motors without using any primary voltage compensators thereby limiting the inrush of starting current. The rotor of the motor is driven at suitable speed in the specified direction of rotation by using crank driving mechanism. Then te rated voltage is applied to the motor. This is enunciated using a case study on a 3- phase, 5hp, NGEF make motor with oscillographic records obtained from the experimentation and is compared with the various starting techniques. Keywords: Induction motor, starter, inrush current, voltage dip, new approach DOI: http://dx.doi.org/10.11591/ijpeds.v1i1.70

Adaptive Direct Torque Control of Induction Motors

In direct torque control (DTC), many induction motor parameters are needed, especially those that affect the values of current and flux required in the control algorithm. DTC of induction machines presents an acceptable tracking scheme for both electromagnetic torque and stator flux. This control scheme depends only on stator measurements. The measurement of the stator flux is very difficult to achieve and can be estimated by an observer. The electromagnetic torque and the stator flux (magnitude and angle) can be determined despite their direct dependence on the knowledge of the stator resistance. This resistance can change up to 180% of its nominal value. The resistance changes with the operational conditions of the motor, such as temperature and frequency. Under these circumstances, a parameter identifier is developed to account for the resistance variations, hence establishing adaptive DTC (ADTC). Moreover, load torque represents the changing tasks required from the motor. In this article, the load torque variations are coupled with stator resistance changes, and the effectiveness of ADTC is investigated. More stable motor operations of polyphase induction motors are obtained under these uncertainties using ADTC.

Diagnostics of eccentricities and bar/end-ring connector breakages in polyphase induction motors through a combination of time-series data mining and time-stepping coupled fe~state-space techniques

This paper develops the foundations of a technique for detection and categorization of dynamic/static eccentricities and bar/end-ring connector breakages in squirrel-cage induction motors that is not based on the traditional Fourier transform frequency-domain spectral analysis concepts. Hence, this approach can distinguish between the of each of the following faults: eccentricities, broken bars, and broken end-ring connectors in such induction motors. Furthermore, the techniques presented here can extensively and economically predict and characterize faults from the induction machine adjustable-speed drive design data without the need to have had actual fault data from field experience. This is done through the development of dual-track studies of fault simulations and, hence, simulated fault signature data. These studies are performed using our proven time-stepping coupled finite-element-state-space method to generate fault case performance data, which contain phase current waveforms and time-domain torque profiles. Then, from this data, the fault cases are classified by their inherent characteristics, so-called or fingerprints. These fault signatures are extracted or mined here from the fault case data using our novel time-series data mining technique. The dual track of generating fault data and mining fault signatures was tested here on dynamic and static eccentricities of 10% and 30% of air-gap height as well as cases of one, three, six, and nine broken bars and three, six, and nine broken end-ring connectors. These cases were studied for proof of principle in a 208 V 60 Hz four-pole 1.2 hp squirrel-cage three-phase induction motor. The paper presents faulty and healthy performance characteristics and their corresponding so-called phase space diagnoses that show distinct fault signatures of each of the above-mentioned motor faults.

Multi-speed polyphase induction motors

It is explained why a polyphase (m > 3) induction motor supplied separately by single consecutive symmetrical components of voltage behaves as a multi-speed motor. As an example a 9-phase 4-speed motor is considered and results of computer simulations are presented. As regards the theory of polyphase machines it is shown that the so-called diagram of decomposition of polyphase induction motor into elementary machines (the graphical representation of a motor model in αβ0 coordinates) is very convenient means for their analysis and modelling.

Diagnostics of bar and end-ring connector breakage faults in polyphase induction motors through a novel dual track of time-series data mining and time-stepping coupled FE-state space modeling

This paper develops the fundamental foundations of a technique for detection of faults in induction motors that is not based on the traditional Fourier transform frequency domain approach. The technique can extensively and economically characterize and predict faults from the induction machine adjustable speed drive design data. This is done through the development of dual-track proof-of-principle studies of fault simulation and identification. These studies are performed using our proven time stepping coupled finite element-state space method to generate fault case data. Then, the fault cases are classified by their inherent characteristics, so-called "signatures" or "fingerprints." These fault signatures are extracted or mined here from the fault case data using our novel time series data mining technique. The dual-track of generating fault data and mining fault signatures was tested here on three, six, and nine broken bar and broken end-ring connectors in a 208-volt, 60-Hz, 4-pole, 1.2-hp, squirrel cage 3-phase induction motor.

Diagnostics of Bar and End-Ring Connector Breakage Faults in Polyphase Induction Motors through a Novel Dual Track of Time-Series Data Mining and Time-Stepping Coupled FE-State Space Modeling

This paper develops the fundamental foundations of a technique for detection of faults in induction motors that is not based on the traditional Fourier transform frequency domain approach. The technique can extensively and economically characterize and predict faults from the induction machine adjustable speed drive design data. This is done through the development of dual-track proof-of-principle studies of fault simulation and identification. These studies are performed using our proven time stepping coupled finite element-state space method to generate fault case data. Then, the fault cases are classified by their inherent characteristics, so-called "signatures" or "fingerprints." These fault signatures are extracted or mined here from the fault case data using our novel time series data mining technique. The dual track of generating fault data and mining fault signatures was tested here on 3, 6, and 9 broken bar and broken end-ring connectors in a 208-V, 60-Hz, 4-pole, 1.2-hp, squirrel cage three-phase induction motor.

Experimental method for synthesis of generalized thermal circuit of polyphase induction motors

A new method for determining the equivalent parameters of a generalized thermal model of induction motors (IM) based on the no-load testing of IM is presented. The representation of the full thermal network of IM is reduced to a system of only three simultaneous equations. By solving these equations three equivalent thermal parameters of the generalized thermal model are obtained. The calculation is based on accurate measurements of the temperature rise in stator windings and the power absorbed by the tested motor. The thermal tests are done in the no-load running of IM (one test is like an open-circuit test and the other two are like short-circuit tests). Hence these methods of testing may be carried out without expensive equipment and their power consumption does not exceed the losses, which occur under full load conditions. With the help of this thermal model the final temperature rise at the full load run according to rated losses, can be easily estimated. Three totally enclosed IM were tested by these methods and the difference in the predicted and measured temperature rise of the stator winding was within 2-3/spl deg/C.

Simplified Measurement Method of Turn-ratios of Auxiliary Windings in Single Phase Induction Motors for General Purpose

The turn-ratio test is required in single phase induction motor to obtain the data necessary to segregate the losses. In this study, for the single phase induction motors for general purpose that are used widely as single phase induction motors it is discussed that the turn-ratio can be derived from the data obtained in the experiment similar to the locked rotor test for the determination of load characteristics in a polyphase induction motor.

Polyphase induction motor performance computed directly by finite elements

Finite element analysis is used to directly compute torques and currents of an induction motor, without need for any equivalent circuit. The AC voltages are applied by means of 0D and 1D finite elements, and the fields and related parameters are computed by nonlinear transient finite element analysis with adaptive time stepping. Equations are derived that allow balanced polyphase motors to be analyzed at any speed without rotating the rotor finite elements, and for torque to be computed directly from power loss. Computed torques and currents of a typical highly saturated polyphase motor with closed rotor bars are shown to agree quite well with measurements.

Comparison of techniques for measurement of shaft currents in rotating machines

Irregularities in the magnetic circuits of motors may result in spurious voltages that lead to shaft currents through the shaft, bearings, bearing supports and closing through the machine framework. The IEEE Standard Test Procedure for Polyphase Induction Motors and Generators discusses the shaft current and presents a measurement method for recording either the voltage across the ends of the shaft or the current. This paper discusses an alternative measurement approach and its application to the identification of shaft current in a large induction machine. Procedures were developed for measuring the shaft current. The procedures include the shunt current method and the measurement using the Rogowski coil. Only the Rogowski coil measurement yields accurate measurements of shaft currents whereas the other method either yields inaccurate measurement or may result in other problems for the machine's integrity. The theory and justification for the superiority of the Rogowski coil method is presented along with supporting test data.