Characteristics Of Synchronous Motor Research Articles

ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ДІАГНОСТИКИ ШИХТОВАНИХ ОСЕРДЬ ТА ВИЗНАЧЕННЯ ПОТОЧНОГО СТАНУ СИНХРОННИХ ДВИГУНІВ

Topicality. Today a large number of synchronous motors with long mean-time-between-failures operate under the conditions of industrial enterprises. They are mainly characterized by difference from the published electromagnetic parameters and degraded energy and reliability indicators, increased heating of the windings and electromagnetic vibrations, which causes a reduction in power on the shaft. Among other reasons, this is due to changes in the properties of laminated stator cores, which is the main structural element that is not replaced during repairs. Purpose. Determination of the main set of independent diagnostic parameters that would reliably distinguish the main types of defects of stator cores, first of all loosening and shorting, during their local testing using induction method and features of artificial neural networks in problems of video identification of core surface and determination of the state of synchronous motors. Metodology. The research methods of theoretical calculations of nonlinear electric circuits with non-sinusoidal power supply and methods of video identification for determination of diagnostic parameters and defects of laminated cores and the theory of neural networks in determining the current state of cores and synchronous motors in general were used during the research. Results. The obtained results specify the conditions of local testing of laminated cores from the standpoint of determining the required set of diagnostic parameters sensitive to the main types of defects, using a contactless test method, reveal the features of the use of neural network analyzers to determine the defects of the tooth zone by video identification and substantiate the principles of application of artificial neural networks in problems of predicting the states of major structural units and synchronous motors in general, due to changing properties of stator cores. Originality. The obtained results allow determining the state of the stator core and taking into account the influence of its change on the current state of synchronous motors with long or intensive operation. Practical value. The research results make it possible to assess the changes in the main parameters and characteristics of synchronous motors, determined by the actual state of the laminated stator cores and take into account their impact on energy efficiency, reliability and other operating parameters of synchronous motors. References 10, figures 7.

Electromagnetic Characteristic Comparison of Superconducting Synchronous Motor Characteristics for Electric Aircraft Propulsion Systems

<div class="section abstract"><div class="htmlview paragraph">This paper describes the comparison of electromagnetic characteristics of two different superconducting-motor structures for electrified aircraft propulsion systems. Future electrified aircraft demand higher output (over 16 kW/kg) and higher efficiency (> 98%) for their motors in comparison with current ones. To satisfy the demands, two kinds of superconducting motors are dealt in this study: one is partially superconducting motors (PSCMs), made of superconducting field coils and copper armature windings; the other is the fully superconducting motors (FSCMs) made of superconducting field/armature windings. They are cooled at 20 K with liquid hydrogen. We designed these two motors with finite element method to obtain the output density of 16-20 kW/kg for future electrified propulsion systems. We selected 3.0- and 5.0 MW superconducting motors, considering the application to aircraft for almost 180 passengers and 44 MW rated power for take-off. Also, we evaluated the motor weight using two kinds of cryostat materials: stainless steel (SUS) and fiber-reinforced plastic (FRP). The results show that the 5.0 MW PSCM using FRP achieved the output density of 16.9 kW/kg and the FSCMs with FRP of 23.5 kW/kg, respectively. The values of their output density are over three times higher than those of synchronous motors using permanent magnets, whose maximum output density value is 5 kW/kg, so far. We also evaluated the motor losses and efficiency; their results described that the efficiency of the PSCM achieved around 98%, while the 5.0 MW FSCM over 99%. The obtained data shows the superconducting motors are one of the key solutions to realize future electrified aircraft propulsion systems.</div></div>

Study of the mechanical and electrical characteristics of the synchronous motor with varying resistive torque

The paper presents the mechanical and electrical characteristics of the synchronous motor for imposed moment variations at the shaft. The test setup is presented, used to determine the electrical and mechanical characteristics of the synchronous motor. Modelling the resistive torque allows the loading with different torsion vibrations. It is presented the used experimental workbench in order to determine the mechanical and electrical characteristics of synchronous motors in such conditions. The engine torque model allows the shaft to be loaded with variable resistive torque values generated by an electromechanical brake. The characteristics presented show the mechanical characteristic of the synchronous motor. Mechanical rotation speed characteristics are presented based on the variation of the resistive torque for 40 seconds, taking note of the value of the resistance when the motor exits synchronism. The determination of these characteristics are made based on the variation of the excitation current applied to the rotor winding of the synchronous motor.

Basic Study on Loss Factor Evaluation of Concentrated Winding Permanent Magnet Synchronous Motor

SUMMARYThis paper describes the influence of pulse width modulation (PWM) inverter harmonic loss on concentrated winding interior permanent magnet synchronous motor characteristics by using finite element method (FEM) analysis and several measurements. In the measurements, the PWM inverter harmonic loss was evaluated by using a PWM inverter and a sinusoidal power supply. By using the FEM analysis, it was confirmed that the PWM inverter harmonic mainly caused an increase of eddy current losses in the magnetic steel sheet and the permanent magnet. The results indicate that higher inductance of the motor is effective in reducing the harmful effects of PWM inverter harmonics.

Effect of Different Winding Switching Methods on Regulating and Energetic Characteristics of Synchronous Motor with Permanent Magnet Excitation

The article contains evaluation of effect of different winding switching methods for synchronous motor with permanent magnet excitation (SMPM) on energetic efficiency, possibility of enlarging the ranges of working speeds and torques, adaptation of regulating characteristics with the aim of using it in particular electric drive. The evaluation is performed at similar values of relative speed and relative inductance. The conditions, which make sensible the usage of 120-degree or 180-degree switching, meanwhile all considered SMPM characteristics are not worse than those under vector control, are defined. It is proved, that there is a possibility to minimize engine's energy consumption by regulating switching angle, as well as change it's mechanical characteristics. In particular, it is possible to get mechanical SMPM characteristic, typical for direct-current motor with series excitation, suitable for usage in electric traction drive.

Comparison of Permanent Magnet Linear Synchronous Motor Characteristics Fed by SPWM Inverter and Sinusoid Voltage Source

Permanent Magnet Linear Synchronous Motor (PMLSM) characteristics are deteriorated seriously by amount of time and space harmonics, which are arisen respectively from the inverter comprised array switches, the motor teeth-slots and distributed windings. The paper presents field-circuit coupled adaptive time-stepping finite element method to comparison research on PMLSM characteristics fed by SPWM voltage inverter and sinusoid supply. The co-simulation is used with the status space functions and time-step finite element functions. The simulation results of PMLSM fed by SPWM voltage source inverter and S-VS were compared and analyzed.

Basic Study on Loss Factor Evaluation of Concentrated Winding Permanent Magnet Synchronous Motor

SUMMARY This paper describes the influence of pulse width modulation (PWM) inverter harmonic loss on concentrated winding interior permanent magnet synchronous motor characteristics by using finite element method (FEM) analysis and several measurements. In the measurements, the PWM inverter harmonic loss was evaluated by using a PWM inverter and a sinusoidal power supply. By using the FEM analysis, it was confirmed that the PWM inverter harmonic mainly caused an increase of eddy current losses in the magnetic steel sheet and the permanent magnet. The results indicate that higher inductance of the motor is effective in reducing the harmful effects of PWM inverter harmonics.

Direct Comparison of Induction Motor and Line-Start IPM Synchronous Motor Characteristics for Semi-Hermetic Compressor Drives

Motors in semi-hermetic compressor drives are mostly fed from line. Because of good cooling conditions, the motors are heavily loaded and employ a specific rotor structure with “C” bore. In the field of semi-hermetic drives, the use of induction motors (IMs) is still dominant, although different motor types with line-starting capabilities, as for example line-start interior permanent magnet synchronous motors (LSIPMSMs), can be used. This work presents the direct performance comparison of a family of commercially available three-phase four-pole IMs for semi-hermetic compressor drives with the equal size prototypes of LSIPMSMs. The motors were rated as 1, 2.5, 3.8, 5.5, 7.5, and 20 hp. The presence of “C” bore in rotor structure can degrade LSIPMSM steady-state performance; therefore, the LSIPMSM designs steady-state performances are evaluated by FEA as well by the experimental method. The motors' dynamic performance is experimentally evaluated as well. The ultimate goal of this study is to reveal the improvement of LSIPMSMs characteristics in comparison to IMs characteristics and to check the possibility for the immediate replacement of existent IMs with LSIPMSMs in the target semi-hermetic compressor application.

Permanent magnet linear synchronous motor characteristics comparison with different topology structures

Permanent magnet linear synchronous motor characteristics comparison with different topology structures

A Study on Permanent Magnet Synchronous Motor Characteristics with Rotor Eccentricity

A Study on Permanent Magnet Synchronous Motor Characteristics with Rotor Eccentricity

Dynamic characteristics of synchronous motors applying a plural sub-magnets scheme to the rotor

This paper treats the optimization of rotor construction in the permanent magnet synchronous motor (PMSM). While the field system of PMSM has generally one magnet per pole, we replace the magnet with plural sub-magnets. The dimensions of each sub-magnet are determined by the concept of pulse width modulation (PWM). By adopting the proposed rotor construction, we can not only reduce the spare harmonics of the air-gap field but also provide space for damper winding around the direct-axis. From the investigation by hybrid FE-BE (coupled finite element and boundary element) method combined with both electric circuit and motion equation, we verify that the proposed construction is effective for practical use in view of both the harmonics reduction and the damping effects.

A new method for the predetermination of the load characteristics of synchronous motors

The methods used hitherto for the determination of synchronousmotor and alternatorload-characteristics are similar, and depend on the estimation of the m.m.f.'s and fluxes underload conditions. This is, however, difficult to do with accuracy, owing to saturation, leakage and the different reluctances of the magnetic paths.The paper shows that tests can be performed at low speeds to reproduce exactly the m.m.f. and flux conditions which occur in a synchronous motor at normal speeds and loads. The errors inherent in previous methods are thereby avoided, enabling the synchronousmotor characteristics to b predetermined with a high degree of accuracy.The method described is applicable to cylindrical-rotor and salientpole machines.

Stability of Synchronous Motors<!--<xref ref-type="other" rid="fn1-10.5594_J12903">*</xref>-->

For the most part, since the advent of talking pictures, motors have been employed whose performance is excellent. The various types of motor, however, differ widely in their ability to resist load irregularities and in their tendency to oscillate when a disturbance occurs. For the more critical applications these factors deserve careful consideration when the type or design is being selected. The principal types of synchronous motor are (1) the variable-reluctance or induced-pole motor, (2) the separately excited motor, (3) the a-c-d-c motor, (4) the hysteresis motor, (5) the low-speed multi-tooth motor (of the type used for electric clocks), (6) the poly-phase, uniform-torque modification of number 5, and (7) selsyn motors. — Many of the characteristics of synchronous motors may best be understood by assuming that the poly-phase winding produces a uniformly rotating magnetic field, but estimating the stiffness and stability demands a knowledge of the manner in which the a-c input varies with mechanical displacement. Generous pole-face grids are essential for stability. A-c-d-c motors have certain elements of instability as well as stabilizing factors, which are not present in straight synchronous motors. The magnitude of these effects can to some extent be controlled by the external circuit arrangements. Selsyn motors are less readily damped than regular synchronous motors, and for this reason arrangements by which the synchronous motors can be interlocked from standstill are of interest.

Pull-in characteristics of synchronous motors

Discussion and authors' closure of a paper by D.R. Shoults, S.B. Crary, and A.H. Lauder published in the December 1935 issue, pages 1385–95, presented for oral discussion at the synchronous machines session of the winter convention, New York, N.Y., January 29, 1936.

Pull-In Characteristics of Synchronous Motors

The differential analyzer has proved its worth in solving various types of difficult problems, of which the determination of the pull-in characteristics of salient pole synchronous motors is typical; but even with the aid of this device it has been necessary in solving this problem to make several simplifying assumptions. The differential analyzer recently completed at the University of Pennsylvania, however, is sufficiently comprehensive in design so that few assumptions are necessary, and the major electrical transients and mechanical forces may be taken into account. Typical solutions obtained by means of this analyzer are presented herewith, together with practical pulling-into-step criteria.

Pull-in characteristics of synchronous motors

Pull-in characteristics of synchronous motors

Static and Dynamic Demonstrations of Harmonic Curves in Two and in Three Dimensions

Motor-driven vibrators combine simple harmonic motions in such a way as to show the complete family of Lissajous' curves on the screen. Addition of a third motion renders three dimensional harmonic figures visible as skew curves in space. These figures exhibit multiple phase changes. Mathematical properties are mentioned. Behavior characteristics of synchronous motors are demonstrated by means of the skew curves. The possibility of a simple, direct laboratory measurement of power factor is indicated.

Complete synchronous motor excitation characteristics

Synchronous motor excitation characteristics published hitherto have been incomplete. If theoretically determined, while forming closed loops, some doubt as to their accuracy has been entertained. When determined experimentally, thay have not been complete, in that the so-called unstable portions of the curves have not been obtained, and generally speaking, the upper portions of the characteristics have been missing. This paper shows complete synchronous motor characteristics, experimentally determined, differing materially from published curves determined by theory. These differences are discussed, and their cause attributed to variations in synchronous impedance. Experimental data is included showing the factors on which synchronous impedance depends, and how it varies with current, saturation and power-factor.

Complete Synchronous Motor Excitation Characteristics

Synchronous motor excitation characteristics published hitherto have been incomplete. If theoretically determined, while forming closed loops, some doubt as to their accuracy has been entertained. When determined experimentally, thay have not been complete, in that the so-called unstable portions of the curves have not been obtained, and generally speaking, the upper portions of the characteristics have been missing. This paper shows complete synchronous motor characteristics, experimentally determined, differing materially from published curves determined by theory. These differences are discussed, and their cause attributed to variations in synchronous impedance. Experimental data is included showing the factors on which synchronous impedance depends, and how it varies with current, saturation and power-factor.