A new approach for determination of moisture in paper insulation of in-situ power transformers by combining polarization-depolarization current and return voltage measurement results

2013 ◽  
Vol 20 (6) ◽  
pp. 2325-2334 ◽  
Author(s):  
S. Sarkar ◽  
T. Sharma ◽  
A. Baral ◽  
B. Chatterjee ◽  
D. Dey ◽  
...  
Keyword(s):  
Power Transformers ◽  
Voltage Measurement ◽  
Depolarization Current ◽  
New Approach ◽  
Measurement Results ◽  
Paper Insulation

scholarly journals Atmospheric CO2, CH4, and CO with CRDS technique at the Izaña Global GAW station: instrumental tests, developments and first measurement results

2017 ◽  
Author(s):  
Angel J. Gomez-Pelaez ◽  
Ramon Ramos ◽  
Emilio Cuevas ◽  
Vanessa Gomez-Trueba ◽  
Enrique Reyes
Keyword(s):  
Drift Rate ◽  
Inlet Pressure ◽  
Response Functions ◽  
Measurement Results ◽  
Ambient Measurements ◽  
Acceptance Tests ◽  
Term Maintenance

Abstract. At the end of 2015, a CO2/CH4/CO Cavity Ring-Down Spectrometer (CRDS) was installed at the Izaña Global Atmosphere Watch station (Tenerife, Spain) to improve the Izaña Greenhouse gases GAW measurement programme, and to guarantee the renewal of the instrumentation and the long-term maintenance of this programme. We present the results of the CRDS acceptance tests, the processing of raw data applied through novel numerical codes, and the response functions used. Also, the calibration results, the implemented water vapour correction, the target gas injection statistics, the ambient measurements performed from December 2015 to July 2017, and their comparison with other continuous in situ measurements are described. The agreement with other in situ continuous measurements is good most of the time for CO2 and CH4, but for CO is just outside the GAW 2-ppb objective. It seems the disagreement is not produced by significant drifts in the CRDS CO WMO tertiary standards. The main novelties are: 1) determination of a slight CO2 correction that takes into account changes in the inlet pressure/flow rate; 2) detailed justification of the use of virtual tanks to monitor the response function changes in time; 3) drift rate determination for the pressure and temperature sensors located inside the CRDS cavity; 4) novelties in the determination of the H2O correction for CO; and 5) determination and discussion of the origin of the CRDS-flow inlet pressure and H2O dependences.

Effect of Switching Method in Polarization and Depolarization Current (PDC) Measurement Technique

2013 ◽  
Vol 64 (4) ◽  
Author(s):  
N. F. Kasri ◽  
M. A. M. Piah ◽  
N. A. Muhamad ◽  
N. A. M. Jamail
Keyword(s):  
Measurement Technique ◽  
Bipolar Transistor ◽  
Optimal Method ◽  
Depolarization Current ◽  
Insulated Gate Bipolar Transistor ◽  
Measurement Analysis ◽  
Measurement Results ◽  
Switching Method ◽  
Over Time

Switching method in Polarization and Depolarization Current (PDC) measurement technique is an appealing area to look at, especially in terms of its behavior over time based monitoring. Previous researches on this technique did not deliberate the effect of switching method in its measurement analysis. Most of the researchers use a conventional HV relay that acts as a switching component. This paper studies the behavior of PDC measurement results and its relationship between the types of switching methods used. It is due to the research hypothesis where different switching method produces distinctive PDC measurement results. Determination of which optimal method that suit with this technique can be made by comparing PDC measurement results; the result which analogous to the reference is considered as the finest method. Two different switching methods were applied in this research, which are HV relays and series-connected of 600V, 30A, Insulated Gate Bipolar Transistor (IGBT).

A New Approach to Quantify Spatial Distribution of Biofilm Kinetic Parameters by In Situ Determination of Oxygen Uptake Rate (OUR)

2009 ◽  
Vol 43 (3) ◽  
pp. 757-763 ◽  
Author(s):  
Xiao-Hong Zhou ◽  
Yu-Qin Qiu ◽  
Han-Chang Shi ◽  
Tong Yu ◽  
Miao He ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Oxygen Uptake ◽  
Kinetic Parameters ◽  
Uptake Rate ◽  
Oxygen Uptake Rate ◽  
New Approach

A New Approach to IDDQ Failure Fault Localization Using Single Shot Logic (SSL) Patterns

2019 ◽  
Author(s):  
Rommel Estores ◽  
Stefaan Verleye
Keyword(s):  
Fault Location ◽  
Fault Localization ◽  
Internal Node ◽  
Precise Determination ◽  
Control Individual ◽  
Single Shot ◽  
New Approach ◽  
Measurement Results ◽  
Defective Area

Abstract In this paper the authors will discuss an application of Single Shot Logic (SSL) patterns used for further localizing IDDQ failures using ATPG constraints and targeted faults. This new method provides the analyst a possibility of performing circuit analysis using IDDQ measurement results as a pass/fail criterion rather than logic mismatches. Once a defective area was partially isolated through fault localization, SSL patterns were created to control individual internal node logic states in a deterministic way. IDDQ was measured at each SSL iteration where schematic analysis can further isolate the failure to a specific location. Two case studies will be discussed to show how this technique was used on actual failing units, with detailed explanation of the steps performed that led to a more precise determination of the fault location in the suspect cell.

In situ determination of a rock mass modulus using a high resolution tiltmeter

1996 ◽  
Vol 33 (2) ◽  
pp. 350-355 ◽  
Author(s):  
Bassam Saleh ◽  
Abdallah I Husein Malkawi ◽  
Pierre A Blum
Keyword(s):  
Rock Mass ◽  
High Resolution ◽  
Boussinesq Model ◽  
New Approach ◽  
Structural Work ◽  
Rock Mass Modulus ◽  
Elastic Rock ◽  
The Impact

A very high resolution tiltmeter (10–8 rad, 0.002 s) developed by P.A. Blum, in 1957 was used to establish a new approach to directly evaluate the in situ average elastic rock-mass modulus. Five tiltmeters were installed on the facades of the Louvre museum to study the deformations induced by internal structural work and by the impact of the Paris metro traffic movement. The measured data from the tiltmeter were used to determine the elastic rock modulus of the museum's foundation using the Boussinesq model. The results obtained by the developed approach are consistent with the typical elastic rock-mass modulus for the rock found in the museum's foundations. Key words: rock-mass modulus, tiltmeter, deformation, Boussinesq model.

scholarly journals In-situ Measurements in Overconsolidated Clay

2015 ◽  
Vol 3 (1-2) ◽  
pp. 68-76
Author(s):  
Eszter Horvath-Kalman
Keyword(s):  
Earth Pressure ◽  
Young Modulus ◽  
In Situ Measurements ◽  
The Other ◽  
Physical Parameters ◽  
Measurement Results ◽  
Processing Of Measurement Results ◽  
Overconsolidated Soils

Abstract The study is about the general genesis process of overconsolidated soils, as well as the effects of the overconsolidated ratio to structures. It will demonstrate the possible methods for the determination of the values of overconsolidated ratio and of earth pressure at rest and of the other soil-physical parameters; further, the processing of measurement results, through which the values of OCR (Overconsolidated ratio) and of λ0 (Earth pressure at rest) and of c, E soil-physical parameters (friction angles, cohesion and Young modulus) in the Kiscelli Clay Marl have been determined by Selfboring Pressuremeter.

scholarly journals Protein adlayer thickness on colloidal nanoparticle determined by Rayleigh-Gans-Debye approximation

2019 ◽  
Author(s):  
L Yuan ◽  
Z Zhai ◽  
L Chen ◽  
X Ge ◽  
D Li ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Curve Surface ◽  
Ex Situ ◽  
Colloidal Nanoparticles ◽  
New Approach ◽  
Debye Approximation ◽  
Wide Range ◽  
Measurement Results ◽  
Important Approach

ABSTRACTReference materials (RM)-assisted Rayleigh-Gans-Debye approximation (rm-RGDA) has been developed and used to in situ determine the size and thickness of the adlayer on the particles in solution. The particle size determined by rm-RGDA is quite close to that measured by electron microscopy but significantly smaller than that measured by DLS. The BSA adlayer absorbed on PS50, PS100 and SiO2 NPs is 3.3, 0.9 and 1.2 nm, respectively, and close to those observed by SEM, which is 4.6, 1.3 and 3.8 nm, respectively. The FTIR analysis results show that the BSA absorbed on larger particles or hydroxyl-abundant surface, e.g. PS100 and SiO2 NPs can lose its secondary structure, e.g. α-helix, to a great extent and that absorbed on a more curve surface, e.g. smaller PS50 particles can largely preserve its secondary structure as its free state. The measurement results show the curvature of the NPs is closely related to the structure change of the adsorbed protein. This method provide a facile and new approach to measure the size and its adlayer change of the hybrid and core-shell structured nanoparticles in a wide range of wavelength.SIGNIFICANCEQuantitative study on the adsorption of the protein on colloidal nanoparticles is an important approach to understand the biophysical effect, compared with other ex situ methods such as TEM and SEM, where the specimen are undergone pre-processing and no longer the original state in measurement. It is, therefore, a big challenge. In order to cope with this challenge, UV-vis based RGDA has been developed and applied to in situ measure the size of the dispersed colloidal nanoparticles and their protein adlayer thickness, where the protein adlayer thickness on the colloidal nanoparticles can be easily determined. We believe this method provide a facile and sensitive way to in situ measure the dimension change of hybrid colloidal nanoparticles.

scholarly journals Fault Identification of In-Service Power Transformer using Depolarization Current Analysis

2017 ◽  
Vol 7 (2) ◽  
pp. 559
Author(s):  
M.A. Talib ◽  
N.A. Muhamad ◽  
Z.A. Malek ◽  
B.T. Phung
Keyword(s):  
Power Transformer ◽  
Diagnostic Testing ◽  
Cost Effective ◽  
Power Transformers ◽  
Depolarization Current ◽  
Significant Information ◽  
Extended Application ◽  
Catastrophic Failures ◽  
Measurement Results

Preventive diagnostic testing of in-service power transformers require system outage and expert’s knowledge and experiences in interpreting the measurement results. The chemical oil analysis may cause significant variance to measurement results due to the different practices in oil sampling, storage, handling and transportation. Thus, a cost effective measuring technique by means of a simpler method that is able provide an accurate measurement results is highly required. The extended application of Polarization and Depolarization Current (PDC) measurement for characterization of different faults conditions on in-service power transformer has been presented in this paper. The oil sample from in-service power transformers with normal and 3 different faults type conditions were sampled and tested for Dissolved Gases Analysis (DGA) and PDC measurement. The DGA results was used to confirm type of faults inside the transformer while the PDC pattern of oil with normal, partial discharge, overheating and arcing were correlated to the oil sample conditions. The analysis result shows that depolarization current provides significant information to defferenciate fault types in power transformer. Thus this finding provides a new alternative in identifying incipient faults and such knowledge can be used to avoid catastrophic failures of power transformers.

Sign in / Sign up

Export Citation Format

Share Document