scholarly journals Stator Vibration Characteristic Identification of Turbogenerator among Single and Composite Faults Composed of Static Air-Gap Eccentricity and Rotor Interturn Short Circuit

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Yu-Ling He ◽  
Wei-Qi Deng ◽  
Bo Peng ◽  
Meng-Qiang Ke ◽  
Gui-Ji Tang ◽  
...  
Keyword(s):  
Unit Area ◽  
Short Circuit ◽  
Harmonic Component ◽  
Air Gap ◽  
Harmonic Vibration ◽  
Fault Identification ◽  
Magnetic Flux Density ◽  
Vibration Characteristic ◽  
Fem Simulations ◽  
The Impact

This paper investigates the radial stator vibration characteristics of turbogenerator under the static air-gap eccentricity (SAGE) fault, the rotor interturn short circuit (RISC) fault, and the composite faults (CFs) composed of SAGE and RISC, respectively. Firstly, the impact of the faulty types on the magnetic flux density (MFD) is analyzed, based on which the detailed expressions of the magnetic pull per unit area (MPPUA) on the stator under different performing conditions are deduced. Then, numerical FEM simulations based on Ansoft and an experimental study are carried out, taking the SDF-9 type fault simulating generator as the study object. It is shown that SAGE will increase the stator vibration at 2f(fis the electrical frequency) which already exists even in normal condition, while RISC and CF will bring in stator vibrations atf, 2f, 3f, and 4fat the same time. The vibration amplitudes under CF are larger than those under RISC. As SAGE increases, the vibration amplitudes of each harmonic component under CF will all be increased, while the development of RISC will decrease the 2nd harmonic vibration but meanwhile increase the 4th harmonic vibration. The achievements of this paper are beneficial for fault identification and condition monitoring of the turbogenerator.

scholarly journals Impact of Different Static Air-Gap Eccentricity Forms on Rotor UMP of Turbogenerator

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Yu-Ling He ◽  
Wei-Qi Deng ◽  
Gui-Ji Tang ◽  
Xiao-Ling Sheng ◽  
Shu-Ting Wan
Keyword(s):  
Theoretical Analysis ◽  
Magnetic Flux ◽  
Normal Condition ◽  
Harmonic Component ◽  
Air Gap ◽  
Magnetic Flux Density ◽  
Rotor Vibration ◽  
Salient Pole ◽  
The Impact ◽  
Universal Expression

Theoretical analysis and numerical FEM calculations, together with segmental experiment studies, are used to study the impact of the static air-gap eccentricity forms on the rotor unbalanced magnetic pull (UMP) of turbogenerator. The universal expression of the magnetic flux density under different forms of SAGE is firstly deduced, based on which the detailed UMP formulas for the normal condition and three SAGE cases are obtained, respectively. Then the exciting characteristics of the UMP for each SAGE form to generate vibrations are analyzed. Finally, numerical FEM calculations and segmental experiments are carried out to investigate the effect of SAGE forms on the rotor UMP, taking the SDF-9 type non-salient-pole fault simulating generator as the object. It is shown that, no matter what kind of SAGE occurs, amplitude increments at each even harmonic component of the UMP and the rotor vibration, especially the 2nd harmonic component, will be brought in. Meanwhile, the UMP keeps directing to the very position where the minimum radial air-gap is. Among the different SAGE forms, the rotor offset has the most sensitive effect on the rotor UMP and vibration, while the stator ellipse deformation has the weakest impact.

scholarly journals The Air Gap and Angle Optimization in the Axial Flux Permanent Magnet Motor

1970 ◽  
Vol 110 (4) ◽  
pp. 25-29 ◽  
Author(s):  
C. Akuner ◽  
E. Huner
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Air Gap ◽  
Magnetic Flux Density ◽  
Permanent Magnet Motor ◽  
Axial Flux ◽  
Flux Change ◽  
Torque Values ◽  
The Impact

In this study, the axial flux permanent magnet motor and the length range of the air gap between rotors was analyzed and the appropriate length obtained. NdFeB permanent magnets were used in this study. Permanent magnets can change the characteristics of the motor's torque. However, the distance between permanent magnets and the air gap will remain constant for each magnet. The impact of different magnet angles for the axial flux permanent magnet motor and other motor parameters was examined. To this aim, the different angles and torque values of the magnetic flux density were calculated using the finite element method of analysis with the help of Maxwell 3D software. Maximum torque was obtained with magnet angles of 21°, 26°, 31.4°, and 34.4°. Additionally, an important parameter for the axial flux permanent magnet motor in terms of the air gap flux was analyzed. Minimum flux change was obtained with a magnet angle of 26°. The magnetic flux of the magnet-to-air-gap is under 0.5 tesla. Given the height of the coil, the magnet-to-air-gap distance most suitable for the axial flux permanent magnet motor was 4 mm. Ill. 11, bibl. 4, tabl. 2 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.110.4.280

scholarly journals Impact of Single and Combined Faults Composed of Rotor Eccentricity and Stator Interturn Short Circuit on Electromagnetic Torque Ripples in Synchronous Generator

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Yu-Ling He ◽  
Zhi-Jie Zhang ◽  
Xiao-Long Wang ◽  
Peng Gao ◽  
David Gerada ◽  
...  
Keyword(s):  
Experimental Study ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Magnetic Flux Density ◽  
Electromagnetic Torque ◽  
Element Calculation ◽  
Single Fault ◽  
Torque Ripples ◽  
The Impact ◽  
Short Circuit Fault

In order to comprehensively study and identify the electromagnetic torque (EMT) difference among the single static air-gap eccentricity (SAGE) fault, the single stator interturn short circuit fault (SISC), and the combined fault composed of these two, this article investigates the EMT ripple properties due to the mentioned three faults. Different from other studies, this paper considers not only the effect of the single fault types but also the impact of the single fault combinations on the EMT ripple characteristics. Detailed EMT expressions for each fault are firstly derived on the basis of the magnetic flux density (MFD) analysis. Then, finite element calculation and experimental study on a CS-5 prototype generator with two poles at 3000 rpm, which is specifically designed and manufactured ourselves, are carried out to validate the analysis result. It is found that the three faults will induce different ripple components in EMT. The combined faults have the most intensive impact sensitivity on the EMT ripples, while the single SAGE fault ranks the last in the impact effect.

Magnetic Field Finite Element Analysis of Generator with Rotor Inter-Turn Short-Circuit Fault

2014 ◽  
Vol 707 ◽  
pp. 343-347
Author(s):  
Yong Gang Li ◽  
Bing Han
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Magnetic Flux ◽  
Flux Density ◽  
Early Stage ◽  
Short Circuit ◽  
Air Gap ◽  
Operating Conditions ◽  
Magnetic Flux Density ◽  
Short Circuit Fault

Rotor inter-turn short-circuit is a common fault in generator and it is a research hotspot to identify the fault at its early stage. Considering the disadvantage of circuit analytical method, this paper establishes a 2D transient finite element electromagnetic-circuit coupling model, and calculates the magnetic field at normal and fault situations through the powerful post-processing function of ANSOFT, then magnetic flux density cloud pictures and air-gap magnetic flux density curves of different operating conditions are got. Using MATLAB to analyze and deal with the air-gap flux density cures, we can get the differences of faults in different levels and different positions, which provide a basis for further study of rotor inter-turn short-circuit fault.

Analysis of Turbo-Generator Circulating Current Between Stator Winding Parallel-Connected Branches Under Fault Conditions

2005 ◽  
Author(s):  
Shuting Wan ◽  
Heming Li ◽  
Yonggang Li ◽  
Fanchao Meng
Keyword(s):  
Second Harmonic ◽  
Short Circuit ◽  
Air Gap ◽  
Normal Operation ◽  
Magnetic Flux Density ◽  
Stator Winding ◽  
Magnetomotive Force ◽  
Circulating Current ◽  
Turbo Generator ◽  
Rotor Winding

Firstly analyzes the generator parameters of air-gap magnetomotive force, magnetic permeability, magnetic flux density, the stator winding parallel-connected branches electromotive force distribution, and gets voltage difference and circulating current expressions between stator winding parallel-connected branches. Secondly, through analyzing the parameters changing on normal operation and fault condition, the circulating current characteristics are given based on the expressions, which are that hasn’t the circulating current when generator operates normally, and second harmonic circulating current will increase when the rotor winding inter-turn short circuit fault has happened, and fundamental circulating current will increase when stator winding inter-turn short circuit or air-gap eccentricity fault has happened. Considering that different fault has different circulating current characteristic, the generator fault diagnosis method based on circulating current was developed. Finally practically acquires SDF-9 generator data on the fault, the results of verification show that analysis is correct.

scholarly journals Comparative Study of 3D Simulation and Experiment on Stator MPPUA of Generator under FWISC Faults with Different Degrees

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Yu-Ling He 1 ◽  
Qing-Fa Meng 1 ◽  
Ping Wang 2 ◽  
Ming-Xing Xu 1
Keyword(s):  
Comparative Study ◽  
Normal Condition ◽  
Quantitative Data ◽  
Unit Area ◽  
Short Circuit ◽  
Harmonic Component ◽  
Exciting Force ◽  
Increasing Trend ◽  
Simulation And Experiment ◽  
Harmonic Components

In order to study the impacts of the stator magnetic pull per unit area (MPPUA) characteristics under different field winding inter-turn short-circuit (FWISC) degrees in generator, comparative study of 3D numerical simulations and experiments are respectively taken to calculate the quantitative data of stator MPPUA by finite-element method (FEM) in this paper. Firstly, the nature exciting force of stator vibration, which is called MPPUA, is carried out. Then simulations data on MPPUA under normal condition and different short-circuit degrees are obtained. Finally, the variation rules of MPPUA characteristics by experiments under different conditions are studied. The results show that in normal condition the main harmonic components of MPPUA consist of only 6th-harmonic component. However, the occurrence of FWISC will bring in extra 1st, 2nd, 3rd, 4th and 5th-harmonic components to MPPUA. Meanwhile, with the increasing of the rotor short circuit degrees, the amplitudes of 1st, 2nd, 3rd, 4th and 5th-harmonic components will present an increasing trend. However, the amplitudes of 6th-harmonic component will present a decrease trend.

scholarly journals Impact of the Field Winding Interturn Short-Circuit Position on Rotor Vibration Properties in Synchronous Generators

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xing-Hua Yuan ◽  
Yu-Ling He ◽  
Man-Yu Liu ◽  
Hui Wang ◽  
Shu-Ting Wan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Short Circuit ◽  
Magnetic Flux Density ◽  
Synchronous Generators ◽  
Rotor Vibration ◽  
Element Analysis ◽  
Monitoring And Diagnosis ◽  
Vibration Properties ◽  
The Finite Element Analysis ◽  
The Impact

This paper investigates the effect of the field winding interturn short-circuit (FWISC) position on the rotor vibration properties in turbo generators. Different from the previous studies which focused on the influence of the short-circuit degree, this work pays much attention to the impact of the short-circuit position on the rotor unbalanced magnetic pull (UMP) properties and vibration characteristics. The theoretical UMP model is firstly deduced based on the analysis of the magnetic flux density (MFD) variation. Then, the finite element analysis (FEA) is performed to calculate the UMP data. Finally, the rotor vibrations are tested on a CS-5 prototype generator which has two poles and a rated capacity of 5 kVA. It is shown that the occurrence of FWISC will greatly increase the UMP as well as the rotor vibration. In addition to the short-circuit degree, the short-circuit position will also affect the UMP and vibration. The nearer the short-circuit position is to the big rotor teeth, the larger the UMP and vibration will be. The proposed study in this paper will be beneficial for the monitoring and diagnosis of FWISC faults.

EFFECT OF INTERNAL POWER-ANGLE ON TURBO-GENERATOR ROTOR VIBRATION CHARACTERISTICS UNDER ECCENTRICITY FAULTS

2014 ◽  
Vol 38 (1) ◽  
pp. 63-79 ◽  
Author(s):  
Shuting Wan ◽  
Yuling He ◽  
Changgeng Zhan
Keyword(s):  
Unit Area ◽  
Air Gap ◽  
Vibration Characteristics ◽  
Magnetic Flux Density ◽  
Radial Vibration ◽  
Rotor Vibration ◽  
Magnetomotive Force ◽  
Turbo Generator ◽  
Faults Diagnosis ◽  
Theoretical Results

This paper investigates the effect of the turbo-generator internal power-angle on the rotor radial vibration characteristics under air gap eccentricity faults. Firstly the air gap magnetomotive force, the magnetic permeance and the magnetic flux density of the eccentricity faults is deduced, and the formula of the magnetic pull per unit area is obtained. Then the restrictive factors of the magnetomotive force and the internal powerangle are analyzed. The unbalanced magnetic pull (UMP) that acts on the rotor is further deduced, and the rotor vibration characteristics are given. Finally the experiments are taken on a SDF-9 non-salient fault simulating generator to verify the theoretical results. The investigation results of this paper will be beneficial to air gap eccentricity faults diagnosis of turbo-generator.

INVESTIGATION ON STATOR AND ROTOR VIBRATION CHARACTERISTICS OF TURBO-GENERATOR UNDER AIR GAP ECCENTRICITY FAULT

2011 ◽  
Vol 35 (2) ◽  
pp. 161-176 ◽  
Author(s):  
Shuting Wan ◽  
Yuling He
Keyword(s):  
Magnetic Flux ◽  
Unit Area ◽  
Air Gap ◽  
Vibration Characteristics ◽  
Magnetic Flux Density ◽  
Rotor Vibration ◽  
Turbo Generator ◽  
Dynamic Eccentricity ◽  
Static Eccentricity ◽  
Theoretical Results

This paper investigates the stator and the rotor vibration characteristics of turbo-generator under the air gap eccentricity fault. Firstly the air gap magnetic flux density of the fault is deduced, and the formula of the magnetic pull per unit area acting on the stator and the unbalanced magnetic pulls of x-axis and y-axis acting on the rotor are respectively gotten. Then the static eccentricity, the dynamic eccentricity and the mixed eccentricity are respectively studied to analyze the stator and the rotor vibration characteristics. Finally experiments are done on a SDF-9 non-salient fault simulating generator to verify the theoretical results. The investigation results of this paper will be beneficial to the air gap eccentricity fault diagnosis of turbo-generator.

EFFECT OF STATIC ECCENTRICITY AND STATOR INTER-TURN SHORT CIRCUIT COMPOSITE FAULT ON ROTOR VIBRATION CHARACTERISTICS OF GENERATOR

2015 ◽  
Vol 39 (4) ◽  
pp. 767-781 ◽  
Author(s):  
Yu-Ling He ◽  
Meng-Qiang Ke ◽  
Fa-Lin Wang ◽  
Gui-Ji Tang ◽  
Shu-Ting Wan
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Short Circuit ◽  
Air Gap ◽  
Vibration Characteristics ◽  
Magnetic Flux Density ◽  
Radial Deformation ◽  
Rotor Vibration ◽  
Harmonic Vibrations ◽  
Static Eccentricity

This paper investigates the radial rotor vibration characteristics under static air-gap eccentricity and stator inter-turn short circuit composite faults. The air-gap magnetic flux density is firstly deduced to obtain the unbalanced magnetic pull (UMP) on rotor. Then the rotor vibration characters, as well as the developing trend between the faulty parameters and the vibration amplitudes, are analyzed. Finally, the experiments are taken on a SDF-9 type simulating generator. It is shown that the radial deformation possibility, the 2nd, 4th, and 6th harmonic vibrations will be caused by the composite faults. Besides, the development of the inter-turn short circuit, the increment of the static eccentricity, and the rise of the exciting current will all get the deformation trend and the vibration amplitudes increased.

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