Start Permanent Magnet Synchronous Motor Research Articles

Risk of irreversible demagnetisation under transient states of the line start permanent magnet synchronous motor taking into account magnet temperature

Risk of irreversible demagnetisation under transient states of the line start permanent magnet synchronous motor taking into account magnet temperature

Comparative analysis of the power parameters of a line start permanent magnet synchronous motor using professional FEM packages and in-house software

Comparative analysis of the power parameters of a line start permanent magnet synchronous motor using professional FEM packages and in-house software

A new approach to design line start permanent magnet synchronous motors

<span lang="EN-US">The article describes a new approach to line start permanent magnet synchronous motors (LSPMSM) design process. This different, novel approach is based on the modification of mass-produced induction motors. The presented method facilitates and expedites the electrical motor design process. A field-circuit model of the motor has been created to expound the methodology of the process. Then, the machine's geometry was changed to apply permanent magnets. The problems and benefits associated with the use of permanent magnets were described. The created model was tested. The authors examined the operation of the LSPMSM motor in different states, such as starting, no-load, and blocked-rotor tests. Electromechanical characteristics have been plotted. The simulation results were compared with the parameters and characteristics of the induction motor. The conducted tests proved the correctness of the design process. The operational properties of the motor have been improved. Moreover, the validity of using LSPMSM motors instead of induction motors has also been demonstrated.</span>

Experimental performance verification of radial and axial flux line start permanent magnet synchronous motors

Experimental performance verification of radial and axial flux line start permanent magnet synchronous motors

Analytical and FEM Methods for Line Start Permanent Magnet Synchronous Motor of 2.2kW

This paper has developed electromagnetic equations based an analytical model to design a three-phase line start permanent magnet synchronous motor (LSPMSM) of 2.2 kW. In order to enhance the torque and efficiency of this machine, an optimized slot shape of rotor permanent magnet is proposed. The analytical model is first presented to evaluate the magnetic characteristics, and then analytical expressions are derived under the open circuit condition. The influence of the magnet size variables on the analytical model is considered to investigate the magnetic leakage flux and flux density distribution in air gaps. Moreover, the variation of design has a significant impact on the steady-state performance characteristics of this motor. In addition, in order to check the output results from the analytical model, a finite element method is developed to evaluate these solutions. Finally, experimental and simulation results have been compared and analyzed to validate the development of method.

An observer design for the flux of line start permanent magnet synchronous motors

The permanent magnet flux is an important model parameter that determines the operation of the line start permanent magnet synchronous motor. It is degraded with operating time due to the permanent magnet demagnetization which is principally caused by the armature magnetic field interaction and operating temperature. This paper introduces an observer design study aimed at estimating the permanent magnet flux of the line start permanent magnet synchronous motor from the measurement of stator currents. Derived from the mathematical description in the dq0 reference frame, a model of the motor with state variables of stator currents, magnetic fluxes and rotor angular frequency is considered. Model analysis and with a new flux variable setting allow an estimation of the rotor flux through the open loops from the stator currents. The observer is then designed with a constant gain for the system with states of stator currents and permanent magnet flux. Simulation confirms the efficiency and robustness of the designed observer.

Analysis of a new concept of Line Start Permanent Magnet Synchronous Motor

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

Effect of Stator Slots on Electromagnetic Performance of a High-Voltage Line-Start Permanent Magnet Synchronous Motor

It is well known that the use of slotted stators in motors produces undesirable effects, such as magnetic flux distortion, additional losses, ripple torque, and vibration. However, a large number of studies pay more attention to stator slots and magnetic slot wedges (MSW) in asynchronous motors and permanent magnet motors, ignoring the same problems in large capacity high voltage line start permanent magnet synchronous motors (HVLSPMSM). In order to disclose the effect of the stator slot on HVLSPMSMs, the no-load air gap magnetic field distribution and stator leakage reactance are studied. Meanwhile, the differences in the starting torque, pull-in torque and pull-out torque of four slot models are compared, and the starting performance is more affected by stator slot. In practical manufacturing, the application of MSWs is the main way to change the electromagnetic performance of stator slots, so the influence of MSWs under different permeabilities on the performance of HVLSPMSMs is investigated. Finally, the effect of a stator slot on the motor starting performance and the rated performance are verified by prototypes and experimental tests, which provide a reference for the application of MSWs in HVLSPMSMs.

Modelling and experimental verification of temperature effects on back electromotive force waveforms in a line start permanent magnet synchronous motor

PurposeThis paper aims to elaborate the method and algorithm for the analysis of the influence of temperature on back electromotive force (BEMF) waveforms in a line start permanent magnet synchronous motor (LSPMSM).Design/methodology/approachThe paper presents a finite element analysis of temperature influence on BEMF and back electromotive coefficient in a LSPMSM. In this paper, a two-dimensional field model of coupled electromagnetic and thermal phenomena in the LSPMSM was presented. The influence of temperature on magnetic properties of the permanent magnets as well as on electric and thermal properties of the materials has been taken into account. Simulation results have been compared to measurements. The selected results have been presented and discussed.FindingsThe simulations results are compared with measurements to confirm the adequacy of this approach to the analysis of coupled electromagnetic-thermal problems.Originality/valueThe paper offers appropriate author’s software for the transient and steady-state analysis of coupled electromagnetic and thermal problems in LSPMS motor.

Experimental and Simulation Studies of Partial Demagnetization Process of Permanent Magnets in Electric Motors

For the analysis of the process of partial demagnetization of permanent magnets (PMs) in electric machines, a field model of coupled electromagnetic and thermal phenomena was proposed. In the proposed approach the non-linearity of the magnetic circuit, the effect of temperature on the magnetic, electrical and thermal properties of the materials as well as the developed method for modeling the process of partial demagnetization of the PMs were taken into account. In order to verify the usefulness and effectiveness of the developed algorithm as well as software for analyzing the impact of temperature and the process of partial demagnetization of the magnets on the operation of a PM motor, the results of calculations were compared with the results of experimental studies. The experimental tests were carried out on a specially designed and constructed measuring test stand. The results of the research on the process of partial demagnetization of magnets in the line start permanent magnet synchronous motor (LSPMSM) are presented and the conclusions resulting therefrom have been formulated.

Performance verification of novel rotor line start PMSM

In this study, 5.5-kW 1500 rpm IEC-60034-30-1:2014-IE4 super premium efficiency class Line Start Permanent Magnet Synchronous Motor (LS-PMSM) was presented with an innovative rotor design utilizing two different slot types have been used. The slots offered in two different geometries make a significant contribution to the motor in the form of a high starting torque thus increasing the synchronization ability. The prototype was manufactured for the optimal model obtained via analytical methods and Finite Element Software. Torque ripples that pose an important issue for permanent magnet motors were tried to be reduced by way of a skewed stator structure. In addition, motor frame and stator main dimensions were acquired from a standard IE2 induction motor design during the manufacturing of the prototype. Experimental studies for the suggested LS-PMSM topology put forth a 6 % higher efficiency in comparison with low efficiency IE2 standard induction motors with the same shaft power. Results for the starting performance, torque ripples and back-EMF were presented for the prototype motor under a constant load of 0-1.25 p.u. It was verified as a result of the study that LS-PMSMs can be used as an alternative to induction motors in pump and fan industrial applications.

Motor Current Signature Analysis-based Non-invasive Recognition of Mixed Eccentricity Fault in Line Start Permanent Magnet Synchronous Motor

— In this study, a cost-effective and non-invasive detection strategy is proposed for three-phase line start permanent magnet synchronous motor (LSPMSM) under mixed eccentricity fault using motor current signature analysis. In this respect, theory of air gap magnetic field in eccentric LSPMSM is presented. The detection strategy is examined through modeling and experimental studies. Two-dimensional time stepping finite element method is employed to calculate the motor parameters. Effects of mechanical load and fault severity on eccentric LSPMSM are also investigated. Different fault-related components are scrutinized and the most effective features are identified for this new type of electrical motor. The results indicate that amplitudes of fault-related components at rotor frequency are precise for early detection of mixed eccentricity in LSPMSM. Finally, an efficient frequency pattern as well as detection criterion is specified.

Analysis and Prediction of Cogging Torque and ripples in output Torque of Permanent Magnet Synchronous Motor and Line Start Permanent Magnet Synchronous Motor

Permanent magnet (PM) motors are rapidly replacing the squirrel cage induction motors for its energy efficient operation, smooth control and high power density. Although PM Motors are energy efficient, they are inherently affected by cogging torque and torque ripple. Magnetic alignment between teeth of stator and permanent magnet of rotors produce cogging torque. Torque ripple is a dynamic oscillation during steady-steady operation which leads to various mechanical anomalies like vibration, noise and rotor stress. Torque ripple is produced in PM motors because of non-sinusoidal distribution of flux, saturation, improper selection of slots etc., these ill effects will deteriorate the starting and steady-state performance of motors. So it is very vital to make analysis and prediction of cogging torque and torque ripples to make the motor more effective. Now a day's minimizing the torque ripples and cogging torque are gaining importance in PM motor designs. In this proposed work, the cogging torque analysis and torque ripple analysis of permanent magnet motor and line start permanent magnet motor has been done and reported.

Analysis of rotor asymmetry fault in three-phase line start permanent magnet synchronous motor

This article proposed a detection scheme for three-phase Line start permanent magnet synchronous motor (LSPMSM) under different levels of static eccentricity fault. Finite element method is used to simulate the healthy and faulty LSPMSM with different percentages of static eccentricity. An accurate laboratory test experiment is performed to evaluate the proposed index. Effects of loading condition on LSPMSM are also investigated. The fault related signatures in the stator current are identified and an effective index for LSPMSM is proposed. The simulation and experimental results indicate that the low frequency components are an effective index for detection of the static eccentricity in LSPMSM.

Performance Enhancement of Line Start Permanent Magnet Synchronous Motor With a Special Consequent Pole Rotor

This paper presents the development of line start permanent magnet synchronous motor (LSPMSM) employing a special consequent pole rotor. The proposed rotor structure uses both circumferentially magnetized spoke shape and radially magnetized arc shape magnets. The combination of spoke and arc shape is arranged to provide consequent magnetic poles. This new rotor structure improves the motor performance and consumes less magnet volume. The time-stepping finite element analysis (FEA) is used to evaluate transient and steady state performances. Extensive simulation studies are performed to establish the supremacy of proposed rotor structure over benchmarked spoke and some other known rotor structures. For experimental validation, prototypes of machine are built using (a) proposed magnet configuration, and (b) spoke type configuration having circumferentially magnetized magnets which is used as baseline motor. Rigorous experimental studies are carried out and it is observed that the proposed structure offers 4% improvement in the full load efficiency over the benchmarked spoke rotor LSPMSM yet by saving 10% magnet volume. Further, it is observed that the performance of the proposed machine is enhanced for direct online (DOL) as well as variable frequency drive (VFD) fed supply operation.

Analysis of the Partial Demagnetization Process of Magnets in a Line Start Permanent Magnet Synchronous Motor

The paper justifies the validity of analyzing the impact of temperature and the process of partial demagnetization of magnets on the operating parameters of machines. To analyze this impact, a field model of coupled electromagnetic and thermal phenomena in a permanent magnet synchronous motor was proposed. The non-linearity of the magnetic circuit, the effect of temperature on the magnetic, electrical and thermal properties of the materials as well as the developed method of modeling the process of partial demagnetization of the magnet were taken into account. Based on this model, an algorithm and software were developed to analyze the effect of temperature and the process of partial demagnetization of magnets on the work of the line start permanent magnet synchronous motor (LSPMSM). The elaborated software was used to study the effect of temperature during the motor starting phase on the magnetization state of the magnets after the start-up process. The calculation results were compared to the results of experimental studies. The experimental tests were carried out on a specially constructed test stand. The results of the research on the process of partial demagnetization of the magnets are presented and the conclusions resulting therefrom formulated.

An efficient acoustic-based diagnosis of inter-turn fault in interior mount LSPMSM

This paper investigates the use of acoustic signals in diagnosing stator inter-turn faults in Line Start Permanent Magnet Synchronous Motors (LSPMSMs). Singular spectrum analysis (SSA) is proposed to analyze the acoustic signal for fault detection. The proposed methodology involves collection of experimental acoustic data using a smartphone from an interior mount LSPMSM under different loading levels, healthy as well as faulty motor cases where different number of turns are shorted to emulate different fault levels. Acoustic signal for each case is analyzed using SSA, which results in decomposition of the signal into periodic components and noise. Fast Fourier Transform (FFT) of each component is carried out to find the unique frequency representative for each case. The results with the proposed methodology show that it is capable to detect the occurrence of inter-turn fault under different loading levels with the capability of distinguishing fault severity with readily available acoustic sensor of a smart phone. In addition, it is possible to differentiate between the load and no-load modes of operation.

Recognition of Stator Winding Inter-Turn Fault in Interior-Mount LSPMSM Using Acoustic Signals

This paper presents a novel stator inter-turn fault diagnosis method for Line Start Permanent Magnet Synchronous Motors (LSPMSMs) using the frequency analysis of acoustic signals resulting from asymmetrical faults. In this method, acoustic data are experimentally collected from a 1 hp interior mount LSPMSM for different inter-turn fault cases and motor loading levels, while including the background noise. The signals are collected using a smartphone at a sampling rate of 48,000 samples per second. The signal for each case is analyzed using fast Fourier transform (FFT), which results in the decomposition of the signal into its frequency components. The results indicate that, for both no-load and full-load conditions, 39 components are observed to be affected by the faults, whereby their amplitudes increase with the fault severity. The 40-turns fault shows the highest difference in the component amplitudes compared with the healthy condition acoustic signal. Therefore, this diagnostic method is able to detect the stator inter-turn fault for interior mount LSPMSMs. Moreover, the method is simple and cheap since it uses a readily available sensor.

Life Cycle Energy Cost Assessment for Pump Units with Various Types of Line-Start Operating Motors Including Cable Losses

The paper presents a comparative analysis of life-cycle energy consumption for three different types of 4 kW line-start motors used in a pump unit with throttling: the most widely used induction motor with IE3 efficiency class, line start permanent magnet synchronous motor with IE4 efficiency class and line start synchronous reluctance motor with IE4 efficiency class. The operating cycle for pump units with constant flow is considered for the above-mentioned types of motors taking into account not only the losses in the pump and motor, but also in the power supply cable. It is shown that the line start synchronous reluctance motor without magnets has the highest efficiency over the entire considered loading range. However, its power factor is lower than that of the synchronous motor with magnets and therefore it has more significant losses in power supply cable. Despite this disadvantage, the line-start reluctance motor is a good alternative to widespread induction motor since it allows saving of approximately 4000 euro more than the latter during the 20 years life cycle. It also provides similar savings in comparison to the permanent magnet synchronous motor, but unlike it, it does not have costly rare-earth materials in the rotor.

Durum İzleme ve İstatistiksel Süreç Kontrolü Kullanarak Şebeke Kalkışlı Daimi Mıknatıslı Senkron Motorda Rulman Arızası Tespiti

Line start permanent magnet synchronous motor (LSPMSM) is used in many applications in industrial environments such as belt systems and fan systems due to its high efficiency, high power factor and self-starting features. Early detection of LSPMSM failures will eliminate production losses and high maintenance and repair costs. In this study, SCADA-based online condition monitoring and fault detection method is proposed for detecting bearing failures of LSPMSM. For this purpose, SCADA based condition monitoring automation was carried out primarily to monitor motor current and voltage data. The normal operating limits of the motor were determined by analyzing the current signals monitored under different speed and load conditions from a healthy LSPMSM with an exponential weighted moving average (EWMA) based statistical process control method. Then, fault detection was made according to the exceeding of these limits by using EWMA data of the current signals of a the LSPMSM in case of faulthy. The obtained results showed that the designed SCADA automation has the ability to collect and save data safely, and the proposed fault detection method is a successful tool for the detection of bearing failures of LSPMSM.