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.

scholarly journals The Control of Squirrel-Cage Induction Electromotor with Constant Magnetization Current

2019 ◽  
Vol 4 (5) ◽  
pp. 1-4
Author(s):  
Frederic Biya Motto ◽  
Roger Tchuidjan ◽  
Benoît Ndzana ◽  
Colince Tchinda Tatsa
Keyword(s):  
Control Algorithm ◽  
Rotation Speed ◽  
Dynamic Properties ◽  
Voltage Amplitude ◽  
Stator Current ◽  
Squirrel Cage ◽  
Voltage Vector ◽  
Voltage Frequency ◽  
Magnetization Current ◽  
The Given

In this paper, we study the control algorithm of electromagnetic torque and rotation speed of squirrel-cage induction electromotor with constant magnetization current. We can ensure the constant magnetization current by acting on stator voltage vector. We distinguish two methods of construction of the given magnetization current. The first method is based on variation of stator voltage amplitude from the information just of rotor rotation speed. The second method is based on the stator voltage frequency and amplitude from the stator current information. The second method permits to influence the characteristic equation roots of the control system and to have magnetization current dynamic properties.

scholarly journals Short-Circuit Current Calculation and Harmonic Characteristic Analysis for a Doubly-Fed Induction Generator Wind Turbine under Converter Control

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2471 ◽  
Author(s):  
Jing Li ◽  
Tao Zheng ◽  
Zengping Wang
Keyword(s):  
Wind Turbine ◽  
Analytical Model ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Induction Generator ◽  
Doubly Fed Induction Generator ◽  
Stator Current ◽  
Dc Bus ◽  
Bus Voltage ◽  
Doubly Fed

An accurate calculation of short-circuit current (SCC) is very important for relay protection setting and optimization design of electrical equipment. The short-circuit current for a doubly-fed induction generator wind turbine (DFIG-WT) under excitation regulation of a converter contains the stator current and grid-side converter (GSC) current. The transient characteristics of GSC current are controlled by double closed-loops of the converter and influenced by fluctuations of direct current (DC) bus voltage, which is characterized as high order, multiple variables, and strong coupling, resulting in great difficulty with analysis. Existing studies are mainly focused on the stator current, neglecting or only considering the steady-state short-circuit current of GSC, resulting in errors in the short-circuit calculation of DFIG-WT. This paper constructs a DFIG-WT total current analytical model involving GSC current. Based on Fourier decomposition of switch functions and the frequency domain analytical method, the fluctuation of DC bus voltage is considered and described in detail. With the proposed DFIG-WT short-circuit current analytical model, the generation mechanism and evolution law of harmonic components are revealed quantitatively, especially the second harmonic component, which has a great influence on transformer protection. The accuracies of the theoretical analysis and mathematical model are verified by comparing calculation results with simulation results and low-voltage ride-through (LVRT) field test data of a real DFIG.

scholarly journals Broken Rotor Bars Fault Detection Based on Envelope Analysis Spectrum and Neural Network in Induction Motors

2018 ◽  
Vol 3 (3) ◽  
pp. 106-116
Author(s):  
Saddam BENSAOUCHA ◽  
Sid Ahmed BESSEDIK ◽  
Aissa AMEUR ◽  
Abdellatif SEGHIOUR
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Fourier Transform ◽  
Induction Motors ◽  
Current Signal ◽  
Broken Rotor Bars ◽  
Stator Current ◽  
The Neural Networks ◽  
Modulus Spectrum ◽  
Load Conditions

In this paper, a study has presented the performance of a neural networks technique to detect the broken rotor bars (BRBs) fault in induction motors (IMs). In this context, the fast Fourier transform (FFT) applied on Hilbert modulus obtained via the stator current signal has been used as a diagnostic signal to replace the FFT classic, the characteristics frequency are selected from the Hilbert modulus spectrum, in addition, the different load conditions are used as three inputs data for the neural networks. The efficiency of the proposed method is verified by simulation in MATLAB environment.

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