scholarly journals Theoretical Analysis and Implementation of Photovoltaic Fault Diagnosis

10.5772/62057 ◽  
2016 ◽  
Author(s):  
Yihua Hu ◽  
Wenping Cao
Keyword(s):  
Fault Diagnosis ◽  
Theoretical Analysis

INVESTIGATION ON ELECTROMAGNETIC FORCES AND EXPERIMENTAL VIBRATION CHARACTERISTICS OF STATOR END WINDINGS IN GENERATOR

2014 ◽  
Vol 38 (3) ◽  
pp. 331-345 ◽  
Author(s):  
Shuting Wan ◽  
Changgeng Zhan ◽  
Xiaofang Yao ◽  
Yanmin Deng ◽  
Guowei Zhou
Keyword(s):  
Fault Diagnosis ◽  
Theoretical Analysis ◽  
Electromagnetic Force ◽  
Calculation Model ◽  
Vibration Characteristics ◽  
Method Of Images ◽  
Electromagnetic Forces ◽  
Turbo Generator ◽  
The Relationship ◽  
Superposition Theorem

This paper investigates the electromagnetic forces acting on the stator end windings, by using the stator end windings structure of a 600 MW large-capacity turbo-generator as the analysis object. Firstly, based on the method of images, the Biot–Savart Law and superposition theorem, the calculation model of the stator end windings is proposed. Then, the average electromagnetic forces acted on the end windings and the relationship between radial and tangential electromagnetic force densities are analyzed. The result shows that the tangential electromagnetic force should be treated as radial one and should not be ignored. Finally, the radial and tangential vibrations are measured to verify the theoretical analysis. The investigation results will be beneficial to the binding and fault diagnosis of stator end windings.

Bifurcation and Chaos Research on Dry Friction System in the Spring Fault Condition

2003 ◽  
Vol 17 (22n24) ◽  
pp. 4395-4401
Author(s):  
Wenli Zhao ◽  
Xiaojun Zhou ◽  
Guanwei Luo
Keyword(s):  
Fault Diagnosis ◽  
Theoretical Analysis ◽  
Dynamic System ◽  
Periodic Solutions ◽  
Numerical Computation ◽  
Dynamic Behavior ◽  
Dry Friction ◽  
Two Dimensional ◽  
Bifurcation And Chaos

In this paper, the periodic solutions and stability in the dry friction dynamic system are researched by two-dimensional Poincaremap when the fault has happened in the system because of the spring failure. As a result of numerical computation and theoretical analysis, the bifurcation and chaos will arise when the parameters of system are changed. It is very important to analyze the dynamic behavior to conduct fault diagnosis.

scholarly journals Enhanced Threshold Point Calculation Algorithm for Switch Fault Diagnosis in Grid Connected 3-Phase AC–DC PWM Converters

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1979
Author(s):  
Geun Wan Koo ◽  
DongMyoung Joo ◽  
Byoung Kuk Lee
Keyword(s):  
Fault Diagnosis ◽  
Theoretical Analysis ◽  
Load Condition ◽  
Test Bed ◽  
Calculation Algorithm ◽  
Point Calculation ◽  
Diagnosis Algorithm ◽  
Uninterruptible Power ◽  
Time Required ◽  
Threshold Point

The resilience of systems with alternating current (AC)–direct current (DC) converters has been investigated with the aim of improving switch fault diagnosis. To satisfy this aim, this paper proposes a switch fault diagnosis algorithm for three-phase AC–DC converters. The proposed algorithm operates using the phase current instead of the average current to reduce the calculation time required for fault switch detection. Moreover, a threshold point calculation method is derived using a theoretical analysis, which was lacking in previous research. Using the calculated threshold point, a switch fault diagnosis algorithm is obtained to detect faults independent of the load condition. Using the proposed algorithm, switch faults can be detected within 4 ms, which is the recommended value for uninterruptible power supply (UPS). The theoretical analysis, the operating principle, and the experimental results on a 3-kW grid-tied AC–DC converter test-bed are presented herein, which verify the performance of the proposed algorithm.

Analysis of Shaft Mechanical Runout Forming Mechanism and Diagnostic Technique

2013 ◽  
Vol 753-755 ◽  
pp. 1773-1778
Author(s):  
Juan Yu ◽  
Xiu Feng Wang
Keyword(s):  
Fault Diagnosis ◽  
Theoretical Analysis ◽  
Manufacturing Process ◽  
Surface Defects ◽  
Diagnostic Technique ◽  
Rotating Machinery ◽  
Lateral Vibration ◽  
Forming Mechanism ◽  
Harmonic Components ◽  
Shaft Surface

Harmonic components in holospectrum are mainly due to the lateral vibration, and they are important parameters in fault diagnosis of rotating machinery. However, defects on measuring shaft surface are also included in harmonic components in holospectrum and may lead to misdiagnosis. It’s necessary to study a method to identify the shaft surface defects. Based on the manufacturing process of outer round, this paper studies the forming mechanism of harmonic defects on outer round and their characteristics in holospectrum. An experimental example is also given to validate the theoretical analysis, and the results show that holospectrum can recognize the harmonic defects on outer round well.

Microdiffraction Patterns of Small Metallic Particles II; Theoretical Analysis

1982 ◽  
Vol 40 ◽  
pp. 668-669
Author(s):  
A. Gómez ◽  
P. Schabes-Retchkiman ◽  
M. José-Yacamán ◽  
T. Ocaña
Keyword(s):  
Experimental Data ◽  
Electron Diffraction ◽  
Theoretical Analysis ◽  
Size Range ◽  
Dynamical Theory ◽  
Metallic Particles ◽  
Splitting Effect

The splitting effect that is observed in microdiffraction pat-terns of small metallic particles in the size range 50-500 Å can be understood using the dynamical theory of electron diffraction for the case of a crystal containing a finite wedge. For the experimental data we refer to part I of this work in these proceedings.

Theoretical analysis of a monopole antenna with conducting flat disk above the earth

2001 ◽  
Vol 84 (7) ◽  
pp. 27-36
Author(s):  
Aki Yuasa ◽  
Daisuke Itatsu ◽  
Naoki Inagaki ◽  
Nobuyoshi Kikuma
Keyword(s):  
Theoretical Analysis ◽  
Monopole Antenna ◽  
The Earth ◽  
Flat Disk

Context Aversion, Pavlovian Conditioning, and the Psychological Side Effects of Chemotherapy

1997 ◽  
Vol 2 (2) ◽  
pp. 118-124
Author(s):  
Geoffrey Hall
Keyword(s):  
Animal Model ◽  
Side Effects ◽  
Theoretical Analysis ◽  
Conditioned Response ◽  
Behavioral Strategies ◽  
Contextual Cues ◽  
Anticipatory Nausea ◽  
Laboratory Rats ◽  
Anticipatory Nausea And Vomiting ◽  
Parallel Case

Patients who have undergone several sessions of chemotherapy for cancer will sometimes develop anticipatory nausea and vomiting (ANV), these unpleasant side effects occurring as the patients return to the clinic for a further session of treatment. Pavlov's analysis of learning allows that previously neutral cues, such as those that characterize a given place or context, can become associated with events that occur in that context. ANV could thus constitute an example of a conditioned response elicited by the contextual cues of the clinic. In order to investigate this proposal we have begun an experimental analysis of a parallel case in which laboratory rats are given a nausea-inducing treatment in a novel context. We have developed a robust procedure for assessing the acquisition of context aversion in rats given such training, a procedure that shows promise as a possible animal model of ANV. Theoretical analysis of the conditioning processes involved in the formation of context aversions in animals suggests possible behavioral strategies that might be used in the alleviation of ANV, and we report a preliminary experimental test of one of these.

Posttraumatic Personality Disorder: A theoretical analysis

2006 ◽  
Author(s):  
Clare Pain
Keyword(s):  
Personality Disorder ◽  
Theoretical Analysis
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