scholarly journals PEA Electromagnetic Distortion Reduction by Impedance Grounding and Pulsed Voltage Electrode Configurations

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5837
Author(s):  
Guillermo Mier Escurra ◽  
Armando Rodrigo Mor ◽  
Luis Carlos Castro ◽  
Peter Vaessen
Keyword(s):  
Experimental Testing ◽  
Test Cell ◽  
Acoustic Sensor ◽  
Direct Impact ◽  
High Voltage Direct Current ◽  
Space Charges ◽  
Two Factors ◽  
Distortion Reduction ◽  
Applied Voltage Pulse ◽  
Pulsed Voltage

Space charges are one of the main challenges facing the constantly increasing use of extruded high voltage direct current (HVDC) cables. The Pulsed Electro-Acoustic (PEA) method is one of the most common procedures for space charge measurements of insulation. One issue with the PEA method is distortion due to the crosstalk between the applied voltage pulse and the acoustic sensor. This work analyzed two factors involved in the reduction in this distortion: the influence of the exposed semiconductor distance between the injection electrodes and PEA test cell, and the influence of adding a reactance at the grounding circuit of the PEA test cell. The interaction of these two factors with the distortion was analyzed through a series of experimental testing. Moreover, the performance regarding distortion after applying a developed coaxial injection was compared with the standard non-coaxial injection configuration. It was observed that these two factors had a direct impact on distortion and can be utilized for the reduction in distortion arising from the crosstalk of the applied pulsed voltage. The results can be utilized for the consideration of practical aspects during the construction of a PEA test setup for the measurement of full-size HVDC cables.

scholarly journals Influence of the Pulsed Voltage Connection on the Electromagnetic Distortion in Full-Size HVDC Cable PEA Measurements

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3087
Author(s):  
Guillermo Mier Escurra ◽  
Armando Rodrigo Mor ◽  
Peter Vaessen
Keyword(s):  
Power Systems ◽  
Direct Current ◽  
Electromagnetic Interference ◽  
Experimental Tests ◽  
Test Cell ◽  
Full Size ◽  
High Voltage Direct Current ◽  
Space Charges ◽  
Two Factors ◽  
Pulsed Voltage

Nowadays, with the widespread use of High Voltage Direct Current (HVDC) cables in power systems, the measurements of space charges in full-size cables are becoming more relevant. One of the most common methods used for space charge measurements is the Pulsed Electro-Acoustic (PEA) method. This paper analyzes two factors that influence the electromagnetic interference on the piezoelectric signal. These factors are the connection of the injected pulsed voltage at the PEA test cell and the grounding of the PEA test cell. The influence was analyzed by means of experimental tests to compare different configurations and the electromagnetic distortion created in each one of them. It was observed that the physical location of the pulsed voltage at the electrode has a very important impact on the magnitude of the electromagnetic distortion. Moreover, it is shown that the physical connection of the grounding and the existence of a parasitic capacitance at the PEA test cell are also an important source of distortion.

Thermal breakdown in high voltage direct current cable insulations due to space charges

2018 ◽  
Vol 37 (5) ◽  
pp. 1689-1697 ◽  
Author(s):  
Christoph Jörgens ◽  
Markus Clemens
Keyword(s):  
Electric Field ◽  
Breakdown Voltage ◽  
High Voltage ◽  
Direct Current ◽  
Aging Effect ◽  
Radial Symmetry ◽  
Thermal Breakdown ◽  
Content Type ◽  
High Voltage Direct Current ◽  
Space Charges

Purpose In high voltage direct current (HVDC), power cables heat is generated inside the conductor and the insulation during operation. A higher amount of the generated heat in comparison to the dissipated one, results in a possible thermal breakdown. The accumulation of space charges inside the insulation results in an electric field that contributes to the geometric electric field, which comes from the applied voltage. The total electric field decreases in the vicinity of the conductor, while it increases near the sheath, causing a possible change of the breakdown voltage. Design/methodology/approach Here, the thermal breakdown is studied, also incorporating the presence of space charges. For a developed electro-thermal HVDC cable model, at different temperatures, the breakdown voltage is computed through numerical simulations. Findings The simulation results show a dependence of the breakdown voltage on the temperature at the location of the sheath. The results also show only limited influence of the space charges on the breakdown voltage. Research limitations/implications The study is restricted to one-dimensional problems, using radial symmetry of the cable, and does not include any aging or long-term effect of space charges. Such aging effect can locally increase the electric field, resulting in a reduced breakdown voltage. Originality/value A comparison of the breakdown voltage with and without space charges is novel. The chosen approach allows for the first time to assess the influence of space charges and field inversion on the thermal breakdown.

Strategies, Institutions, and Outcomes Under SNTV in Taiwan, 1992–2004

2010 ◽  
Vol 10 (1) ◽  
pp. 31-59 ◽  
Author(s):  
Dennis P. Patterson ◽  
Hans Stockton
Keyword(s):  
Political Party ◽  
Empirical Test ◽  
Electoral Competition ◽  
Democratic Progressive Party ◽  
Direct Impact ◽  
Two Factors ◽  
Changing Patterns ◽  
Indirect Impacts ◽  
Democratic Elections ◽  
Progressive Party

During the five democratic elections held in Taiwan from 1992 to 2004 inclusive, the formerly dominant Kuomintang Party (KMT) was temporarily supplanted by the Democratic Progressive Party (DPP) as the nation's largest political party. Most explanations for this have focused on party fragmentation and the changing patterns of electoral competition it helped create. These are important factors, but they have not been tested empirically at the level where candidates won and lost legislative seats, the level of the election district. This article offers such an empirical test, and it will show that these two factors had a direct impact on the ability of DPP and KMT candidates to obtain legislative seats. We also show that these factors carried indirect impacts by hurting the ability of the KMT and DPP to nominate in a way that they would obtain all the seats that their obtained vote shares would allow.

Slow Down You’re Moving Too Fast

2015 ◽  
Vol 27 (2) ◽  
pp. 53-63 ◽  
Author(s):  
Annie Lang ◽  
Nancy Schwartz ◽  
Sharon Mayell
Keyword(s):  
Older Adults ◽  
Cognitive Aging ◽  
Attention And Memory ◽  
Younger Adults ◽  
Media Messages ◽  
Two Factors ◽  
The Difference

The study reported here compared how younger and older adults processed the same set of media messages which were selected to vary on two factors, arousing content and valence. Results showed that older and younger adults had similar arousal responses but different patterns of attention and memory. Older adults paid more attention to all messages than did younger adults. However, this attention did not translate into greater memory. Older and younger adults had similar levels of memory for slow-paced messages, but younger adults outperformed older adults significantly as pacing increased, and the difference was larger for arousing compared with calm messages. The differences found are in line with predictions made based on the cognitive-aging literature.

Effects of an Anxiety-Specific Psychometric Factor on Fear Conditioning and Fear Generalization

2017 ◽  
Vol 225 (3) ◽  
pp. 200-213 ◽  
Author(s):  
Christian Baumann ◽  
Miriam A. Schiele ◽  
Martin J. Herrmann ◽  
Tina B. Lonsdorf ◽  
Peter Zwanzger ◽  
...  
Keyword(s):  
Risk Factor ◽  
Anxiety Disorders ◽  
Fear Conditioning ◽  
Longitudinal Design ◽  
Principal Component ◽  
Anxiety And Depression ◽  
Specific Factor ◽  
High Anxious ◽  
Two Factors ◽  
Fear Generalization

Abstract. Conditioning and generalization of fear are assumed to play central roles in the pathogenesis of anxiety disorders. Here we investigate the influence of a psychometric anxiety-specific factor on these two processes, thus try to identify a potential risk factor for the development of anxiety disorders. To this end, 126 healthy participants were examined with questionnaires assessing symptoms of anxiety and depression and with a fear conditioning and generalization paradigm. A principal component analysis of the questionnaire data identified two factors representing the constructs anxiety and depression. Variations in fear conditioning and fear generalization were solely associated with the anxiety factor characterized by anxiety sensitivity and agoraphobic cognitions; high-anxious individuals exhibited stronger fear responses (arousal) during conditioning and stronger generalization effects for valence and UCS-expectancy ratings. Thus, the revealed psychometric factor “anxiety” was associated with enhanced fear generalization, an assumed risk factor for anxiety disorders. These results ask for replication with a longitudinal design allowing to examine their predictive validity.

Studies on the Characterization of Factor VIII and a Co-factor VIII

1974 ◽  
Vol 31 (02) ◽  
pp. 328-338
Author(s):  
M. M. P Paulssen ◽  
H. L. M. A Vandenbussche-Scheffers ◽  
P. B Spaan ◽  
T de Jong ◽  
M. C Planje
Keyword(s):  
Molecular Weight ◽  
Factor Viii ◽  
The Body ◽  
Haemophilia A ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Polysaccharide Content ◽  
Plasma Factor ◽  
Two Factors

SummaryFactor VIII occurs in the body in two different forms. In lymph factor VIII is bound to chylomicra. In plasma, factor VIII is bound to a protein.After delipidation of chylomicra we obtained a glycoprotein with a high polysaccharide content and a molecular weight of approx. 160,000.In plasma, factor VIII is attached to a protein which is present in normal concentrations in plasma of patients with haemophilia A and in serum (co-factor VIII).This factor is deficient in both the plasma and the serum of patients with von Willebrand’s disease.The binding between factor VIII and co-factor VIII is reversible.Some properties of these two factors are described.

The Fractionation Properties of Human Factor VIII (Antihaemophilic Factor)

1960 ◽  
Vol 04 (02) ◽  
pp. 253-260 ◽  
Author(s):  
Franco Gobbi
Keyword(s):  
Factor Viii ◽  
Human Factor ◽  
Maximum Yield ◽  
Factor Vii ◽  
Precipitation Method ◽  
Salting Out ◽  
Human Factor Viii ◽  
Plasma Factor ◽  
Two Factors ◽  
Thromboplastic Activity

SummaryThe fractionation properties of human Factor VIII (antihaemophilic factor, AHF, antihaemophilic globulin) have been studied using a plasma of congenital afibrinogenaemia as a starting material.From a fibrinogen-free plasma, Factor VIII does not precipitate with ethanol at a final concentration of 8%; on the contrary the maximum yield is reached at an ethanol concentration of 25%.With a precipitation method carried out by a one to ten dilution of plasma with distilled water and acidification by N/10 hydrochloric acid to a pFI 5.2, Factor VIII does not precipitate with the euglobulin fraction; when normal plasma is used, such a precipitation is almost complete.With the salting-out fractionation method by ammonium sulphate, Factor VIII precipitates at a concentration between 25 and 33% of saturation either from fibrinogen-free and from normal human plasma.A non-specific thromboplastic activity appears in the fractions prepared by every method. This activity, which is probably due to the activation of seric accelerators, is easily removed by Al(OH)s adsorption. Thus, in order to insure the specificity of Factor VIII assays, the preliminary adsorption of the fractions is indispensable before testing their antihaemophilic activity.Fibrinogen and Factor VIII have different and definite precipitation patterns. When these two factors are associated the fractionation properties of AHF appear quite modified, showing a close similarity to those of fibrinogen. This fact can explain the technical difficulties encountered in the attempt to purify the antihaemophilic factor, and the lack of reproducible procedures for removing fibrinogen without affecting Factor VII.

Sign in / Sign up

Export Citation Format

Share Document