Effect of the Position and the Number of Broken Bars on Asynchronous Motor Stator Current Spectrum

2006 ◽  
Author(s):  
Arezki Menacer ◽  
Sandrine Moreau ◽  
Abdelhamid Benakcha ◽  
Mohamed Said Nait Said
Keyword(s):  
Asynchronous Motor ◽  
Stator Current ◽  
Current Spectrum

Wavelet Transform for Starting Characteristics of Three-Phase Cage Asynchronous Motor

2011 ◽  
Vol 347-353 ◽  
pp. 2987-2990
Author(s):  
Yuan Yuan Li ◽  
Qi Zhong Liu ◽  
Chao Gang Yu
Keyword(s):  
Wavelet Transform ◽  
Performance Test ◽  
Harmonic Wave ◽  
Asynchronous Motor ◽  
Time Frequency ◽  
First Order ◽  
Stator Current ◽  
Electric Machinery ◽  
Three Phase ◽  
Starting Characteristics

In electric machinery performance test, tooth harmonic time-frequency characters of first order of three-phase cage asynchronous motor are most important. The MATLAB software is used to make model and simulate the starting characteristic of asynchronous motor in this article, while the stator current signal of starting motor is de noised by wavelet transform. Through decomposition and reconstruction of wavelet transform, the amplitude of fundamental and harmonic wave in de noising stator current can be reduced, and then the tooth harmonic of first order of starting rotor is extracted. Using the excellent time-frequency analyzing characters of wavelet package transform, the tooth harmonic time-frequency curve is fitted.

scholarly journals Speed Sensorless Control of Six-Phase Asynchronous Motor Drive

2017 ◽  
Vol 4 (1.) ◽  
Author(s):  
Z.M.S. Elbarbary
Keyword(s):  
Induction Motor ◽  
High Performance ◽  
Asynchronous Motor ◽  
Estimation Method ◽  
Motor Drives ◽  
Operating Conditions ◽  
Speed Estimation ◽  
Speed Sensorless ◽  
Stator Current ◽  
Current Error

Multi -phase ac motor drives are nowadays considered for various applications, due to many advantages that they offer when compared to three-phase motors. Cancellation of mechanical position or speed sensors at the motor shaft have the attractions for adjustable speed drives of induction motor to reduce the cost and increase the reliability. To replace the sensor, information of the rotor speed is extracted from measured stator currents and voltages at motor terminals. This paper investigates speed estimation method using model reference adaptive system (MRAS) to improve the performance of a sensorless vector controller of six-phase induction motor (IM). In the proposed method, the stator current is used as the state variable to estimate the speed. Since the stator current error is represented as a function of the first degree for the error value in the speed estimation, the proposed method provides fast speed estimation and is also, more robust to variations in the stator resistance, compared with other MRAS methods. Consequently, this method can improve the performance of a sensorless vector controller in a low speed region and at zero-speed. The proposed method is verified by simulation using the Matlab/Simulink package. The performance of the proposed system is investigated at different operating conditions. The proposed controller is robust and suitable for high performance six-phase induction motor drives. Simulation results validate the proposed approaches.

scholarly journals Modeling of overloads of raising mechanism in metallurgical overhead cranes

2019 ◽  
Vol 62 (8) ◽  
pp. 646-651
Author(s):  
V. V. Varlamov ◽  
M. V. Kipervasser ◽  
A. V. Gerasimuk
Keyword(s):  
Electric Motor ◽  
Asynchronous Motor ◽  
Main Idea ◽  
Support Surface ◽  
Overhead Crane ◽  
Stator Current ◽  
Study Results ◽  
Sequential Solution ◽  
Load Separation ◽  
Emergency Mode

Electromechanical processes occurring when the load is lifted by an overhead crane are considered. The main idea of the work is to identify emergency mode (crane overload) by a method based on control of stator current of lift motor. To obtain stator current diagrams of electric motor, mathematical model of overhead crane (three-mass circuit) has been developed, which includes equations describing elastic properties of crane beams and its rope. A system of (α, β) coordinates, fixed relative to electric motor stator, is adopted to describe the drive asynchronous motor. Lifting cycle is considered as sequence of three steps: choice of the rope “slack”; rope tension; separation of cargo lifting. For each stage, a system of differential equations has been compiled describing motion of masses of overhead crane elements and electrical parameters of electric motor. Initial and boundary conditions for each of the stages were determined. Preliminary transformations of the system of equations to their solution by numerical methods and subsequent modeling of stages of lifting loads were carried out for different weights. Sequential solution of three boundary value problems allows obtaining values of stator currents at time of load separation. Diagrams of stator phase currents of an electric motor were obtained for loads of different mass. Simulation results indicate the presence of fixable difference in magnitudes of stator currents after the load is separated from the support surface. On basis of the developed model and the study results, a functional diagram of crane overload protection device is proposed and its principle of operation is described. It consists in controlling lifted load mass and stator current when liftingthe load. Conclusion is made about feasibility and effectiveness of monitoring electrical values of lifting motor for development of overhead crane protection against overloads. Effectiveness of the proposed system was evaluated.

Diagnostics of Stator Winding Faults in a Three-Phase Asynchronous Motor Using Park’s Vector Analysis

Vestnik MEI ◽  
2021 ◽  
pp. 69-74
Author(s):  
Muhammad Deeb ◽  
◽  
Gassan Ibragim ◽  
Talal Assaf ◽  
◽  
...  
Keyword(s):  
Induction Motor ◽  
Short Circuit ◽  
Asynchronous Motor ◽  
Vector Model ◽  
Stator Winding ◽  
Stator Windings ◽  
Stator Current ◽  
Experimental Part ◽  
Three Phase ◽  
Short Circuit Fault

The study addresses the problem of detecting a short circuit fault in the three-phase induction motor winding by monitoring the stator current Park vector (Lissajous curves). Park's vector model is implemented using the Matlab software package. The experimental part of the study was carried out on an 11 kW three-phase induction motor. The Lissajous curves obtained for a healthy motor and a motor with short-circuited turns under various load conditions were compared with each other. The obtained results have demonstrated the effectiveness of the proposed method for detecting interturn short circuit faults in the three-phase stator windings of induction motors.

scholarly journals Stator and Rotor Faults Diagnosis of Squirrel Cage Motor Based on Fundamental Component Extraction Method

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Guoqing An ◽  
Hongru Li
Keyword(s):  
Short Circuit ◽  
Broken Rotor Bars ◽  
Fundamental Component ◽  
Stator Current ◽  
Current Spectrum ◽  
Squirrel Cage ◽  
Voltage Frequency ◽  
Component Extraction ◽  
Spectrum Experiment ◽  
Stator Fault

Nowadays, stator current analysis used for detecting the incipient fault in squirrel cage motor has received much attention. However, in the case of interturn short circuit in stator, the traditional symmetrical component method has lost the precondition due to the harmonics and noise; the negative sequence component (NSC) is hard to be obtained accurately. For broken rotor bars, the new added fault feature blanked by fundamental component is also difficult to be discriminated in the current spectrum. To solve the above problems, a fundamental component extraction (FCE) method is proposed in this paper. On one hand, via the antisynchronous speed coordinate (ASC) transformation, NSC of extracted signals is transformed into the DC value. The amplitude of synthetic vector of NSC is used to evaluate the severity of stator fault. On the other hand, the extracted fundamental component can be filtered out to make the rotor fault feature emerge from the stator current spectrum. Experiment results indicate that this method is feasible and effective in both interturn short circuit and broken rotor bars fault diagnosis. Furthermore, only stator currents and voltage frequency are needed to be recorded, and this method is easy to implement.

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