Читать книгу Alternative Liquid Dielectrics for High Voltage Transformer Insulation Systems - Группа авторов - Страница 4
List of Illustrations
Оглавление1 Chapter 1Figure 1.1 Basic insulation parameters for aging assessment of oil–paper ins...Figure 1.2 Conceptual illustration of degradation in oil filled apparatus....
2 Chapter 2Figure 2.1 (a) Pongamia seeds, (b) Jatropha seeds.Figure 2.2 Processing of natural esters from seeds.Figure 2.3 (a) Mechanical extraction. (b) Chemical extraction. (c) Transeste...Figure 2.4 (a) Triglyceride structure. (b) Formation of fatty acid methyl es...Figure 2.5 Comparison of ACBDV values of different oil samples.Figure 2.6 (a) Parallel representation of the insulation. (b) Phasor diagram...Figure 2.7 Comparison of (a) pour point values of different oil samples and ...Figure 2.8 Comparison of viscosity values of different oil samples.Figure 2.9 (a) Aging test setup. (b) Oil samples depicting change of color d...Figure 2.10 FTIR spectrum of (a) FR3 aged at 1000 and 2000 hours along with ...Figure 2.11 NMR analysis of (a) new FR3, (b) aged FR3 for 2000 hours, (c) ne...Figure 2.12 (a) DGA analysis of aged FR3 and JAT – ethane, ethylene, and hyd...
3 Chapter 3Figure 3.1 Different types of insulation according to manufacturing processe...Figure 3.2 Failures classified according to failure modes.Figure 3.3 (a) Hydrolysis of cellulose.(b) hydrolysis of esters and (c) ...Figure 3.4 Different mechanical properties of the paper insulation as a func...Figure 3.5 SEM of Kraft paper aged at 130 °C with (a) mineral oil for 261 ho...Figure 3.6 Transformer insulation life versus hottest‐spot temperature, desc...
4 Chapter 4Figure 4.1 Structure of natural ester.Figure 4.2 Structure of synthetic ester.Figure 4.3 Typical photographs of negative streamers in (a) synthetic ester ...Figure 4.4 Fifty percent breakdown voltage of ester fluids versus gap distan...Figure 4.5 Effect of moisture on the AC breakdown voltage of ester fluids.Figure 4.6 PDIV of ester fluids aged at different temperatures under differe...Figure 4.7 Electrical double‐layer formation and ion distribution at (a) oil...Figure 4.8 Molecular structure of cellulose.Figure 4.9 Test loop to simulate oil flow (1: pump, 2: heat regulation, 3: f...Figure 4.10 Ministatic charge tester.Figure 4.11 Couette charging apparatus with (a) front view on inner cylinder...Figure 4.12 Spinning disc system used for streaming electrification of insul...Figure 4.13 Schematic diagram of UV‐Visible spectroscopy measurement.Figure 4.14 UV‐visible absorption spectrum of ester fluid aged at (a) 90 °C,...Figure 4.15 Schematic diagram used for fluorescence measurement.Figure 4.16 EEM spectra of unaged ester fluid.Figure 4.17 EEM spectra of ester fluids aged at (a) 90 °C, (b) 140 °C and (c...Figure 4.18 Experimental setup used for dielectric response spectroscopy....Figure 4.19 Variation of dissipation factor with frequency for aged ester fl...Figure 4.20 IFT and turbidity of ester fluid during thermal aging.Figure 4.21 Viscosity of ester fluid aged at different temperatures.Figure 4.22 Surface potential measurement setup.Figure 4.23 Surface potential decay characteristics of thermally aged ester‐...Figure 4.24 Trap distribution characteristics under (a) positive corona and ...Figure 4.25 (a) Nyquist plot of thermally aged samples, (b) real part of imp...Figure 4.26 Equivalent circuit model.Figure 4.27 Relaxation time with aging temperature.Figure 4.28 (a) Electrical modulus spectrum, (b) real part of modulus with f...Figure 4.29 Variation of organic functional groups in pressboards aged at di...Figure 4.30 Experimental setup used for LIBS studies.Figure 4.31 (a) LIBS emission spectra of aged pressboard, (b) LIBS intensity...
5 Chapter 5Figure 5.1 Illustration of decay particles and their influence on transforme...Figure 5.2 Illustration of the experimental and centrifuge treatment. (a). I...Figure 5.3 Visualization indicating no evidence of colloidal particles in es...Figure 5.4 UV/Vis curves for aged and treated liquids (a) at 115 °C, (b) at ...Figure 5.5 Turbidity of the aged liquids and centrifuged mineral oil.Figure 5.6 Particle count for aged liquids and centrifuged mineral oil (a) a...Figure 5.7 Illustration of the experimental and view of filtering setup. (a)...Figure 5.8 UV/Vis spectral curves for aged oils and filtered oils (a) at 115...Figure 5.9 Absorbance of aged and filtered liquids.Figure 5.10 Turbidity of aged and filtered liquids.Figure 5.11 Particle count for aged oils and filtered oils (a) at 115 °C, (b...Figure 5.12 Variations of turbidity and dissolved decay content with filtrat...Figure 5.13 Variations of turbidity and dissolved decay content with filtrat...
6 Chapter 6Figure 6.1 Dependence inception voltage (a) and inception electrical field s...Figure 6.2 Influence of radius of curvature of high‐voltage point (with d = ...Figure 6.3 Relationship between propagation velocity of the streamers in die...Figure 6.4 Relationship between propagation velocity and testing voltage for...Figure 6.5 Dependence of propagation velocity of negative streamers versus i...Figure 6.6 The sequence of shadowgraph photos of the streamers developing in...Figure 6.7 Examples of shadowgraph photos of third mode streamers developing...Figure 6.8 Examples of light oscillograms registered under positive LI volta...Figure 6.9 Shape of long, positive second mode streamers at 25 μs, shortly b...Figure 6.10 Streamer development according to the liquid phase ionization.Figure 6.11 Literature examples showing the influence of additives on propag...Figure 6.12 Streamer stopping length at various LI voltage (gap distance = 2...Figure 6.13 Examples of light and voltage waveforms registered at negative p...Figure 6.14 Schematic of the experimental setup. Tf: Transformer; D1: Capaci...Figure 6.15 Viscosity of the liquids with change in temperature.Figure 6.16 PD and BDV behavior of natural esters with change in temperature...Figure 6.17 PD behavior of esters with thermal aging. (a) PDIV for different...
7 Chapter 7Figure 7.1 Kinematic viscosity, specific heat capacity, thermal conductivity...Figure 7.2 Variation in the moisture content and saturated water content of ...Figure 7.3 Test results of degree of polymerization (DP) values during the a...Figure 7.4 PDSC and thermogravimetric decomposition characteristics of diffe...Figure 7.5 Acid values of insulation oils and acid catalyzes the hydrolysis ...Figure 7.6 Weibull distribution of AC breakdown voltage of mineral oil and t...Figure 7.7 Comparison of Weibull breakdown voltages and saturated water cont...Figure 7.8 AC breakdown voltage of insulation oil with the combined effects ...Figure 7.9 Breakdown voltage, relative permittivity, dielectric loss, and sp...Figure 7.10 Electrode structure and the transient simulation result of elect...Figure 7.11 Breakdown voltages of oil‐immersed pressboards with different oi...Figure 7.12 Transient simulation result of electric field distribution at th...Figure 7.13 Weibull distributions of surface flashover voltages and comparis...Figure 7.14 Weibull distributions of surface flashover voltages and comparis...Figure 7.15 Weibull distributions of breakdown voltages under needle‐plate a...Figure 7.16 Electric field distribution simulation result of the 3EMO‐IP und...Figure 7.17 Electric field intensity along the axis of the two electrodes fo...Figure 7.18 Distribution transformer filled by the new three‐element mixed i...Figure 7.19 Content of dissolved gases in these five gases in MO and TEMO af...Figure 7.20 Content of dissolved gases in these five gases in MO–paper and T...Figure 7.21 Percentage of H2, CH4, C2H4, C2H6 and C2H2 in these five gases o...Figure 7.22 Percentage of H2, CH4, C2H4, C2H6 and C2H2 in these five gases d...Figure 7.23 Percentage of H2, CH4, C2H4, C2H6, and C2H2 in these five gases ...Figure 7.24 Percentage of H2, CH4, C2H4, C2H6 and C2H2 in these five gases a...Figure 7.25 C2H2, H2, C2H4 triangle for diagnosing thermal and electrical fa...
8 Chapter 8Figure 8.1 “Free radical” mechanism of oxidation of natural esters [9, 10]....Figure 8.2 Applications of nanofluid.Figure 8.3 Two‐step nanofluid preparation methodology.Figure 8.4 Electrical double‐layer formation in a nanofluid.Figure 8.5 Forces existing in nanofluids based on DLVO theory [34].Figure 8.6 Effect of pH on the stability of nanofluids.Figure 8.7 Stability analysis of nanofluids by (a) Sedimentation method, (b)...Figure 8.8 Polarization in nanofluids [48].Figure 8.9 The internal electric field in a polarized nanoparticle [48].Figure 8.10 Methods of thermal conductivity measurement.Figure 8.11 (a) BDV and (b) Moisture content of unfilled and nanofilled vege...Figure 8.12 (a) Moisture content and (b) DP of paper aged in unfilled and na...
9 Chapter 9Figure 9.1 Silica nanoparticles, (a) XRD pattern and (b) TEM image.Figure 9.2 (a) SEM image and (b) EDAX of SiO2 nanoparticles.Figure 9.3 Schematic representation of sample preparation of nanofluid.Figure 9.4 (a) Electrical double layer for nanoparticle in liquid, (b) chemi...Figure 9.5 Particle size analysis of synthetic ester silica nanofluids in a ...Figure 9.6 Comparison of zeta potential of synthetic ester silica nanofluid ...Figure 9.7 Absolute viscosity variation with temperature of the SEF and nano...Figure 9.8 Experimental setup for frequency domain dielectric spectroscopy....Figure 9.9 Variation in dielectric constant of SEF and nanofluids with frequ...Figure 9.10 tan δ variation with frequency of SEF, Type A, Type B meas...Figure 9.11 Variation of conductivity with respect to temperature of synthet...Figure 9.12 Typical current signals recorded in SEF at an alternating polari...Figure 9.13 Variation of peak current (IP ) with voltage in SEF, Type A, and...Figure 9.14 Variation of settled current (IS ) with voltage in SEF, Type A, ...Figure 9.15 Variation of transit time (Tt ) with voltage in SEF, Type A, and...Figure 9.16 Variation of Ionic mobility (μ) with voltage in SEF, Type A, and...Figure 9.17 Variation of conductivity with voltage in SEF, Type A, and Type ...Figure 9.18 Variation of ionic concentration with voltage in SEF, Type A, an...Figure 9.19 Variation of ionic radius with voltage in SEF, Type A, and Type ...Figure 9.20 Experimental setup for measurement of I–U characteristics.Figure 9.21 I–U characteristics of SEF, Type A, and Type B samples under pos...Figure 9.22 I–U characteristics of SEF, Type A, and Type B samples under neg...Figure 9.23 Experimental setup for corona discharge detection using UHF sens...Figure 9.24 Sensitivity of UHF sensor [57].Figure 9.25 Typical (a) UHF signal formed due to corona activity and (b) cor...Figure 9.26 Variation in corona inception of SEF (a) with variation in conce...Figure 9.27 PRPD analysis (a) 2.5% THD and (b) 40% THD, (i) third and fifth ...Figure 9.28 Variation in energy content of UHF signal formed due to corona a...
10 Chapter 10Figure 10.1 Duval's triangle 3 for natural esters.Figure 10.2 Duval's Pentagon 3 method for ester fluids.Figure 10.3 Experimental setup for the surface discharge activity [20].Figure 10.4 View of the hotspot fault setup.Figure 10.5 View of the arcing fault setup.Figure 10.6 Process for the preparation of the samples.Figure 10.7 Acidity of the oil samples at different oil classes.Figure 10.8 Illustration of dissolved gasses under fault conditions: (a) Min...Figure 10.9 Representation of fault gasses in Duval's triangle and Duval's P...Figure 10.10 Illustration of the degradation of the investigated dielectric ...
11 Chapter 11Figure 11.1 Comparison of fluid viscosity as function of temperature.Figure 11.2 Experiment to investigate bubbling at high load, (a) showing the...Figure 11.3 (a) Effect of water on AC dielectric strength, measured accordin...Figure 11.4 Increase in water content of fluid‐impregnated insulation paper....Figure 11.5 Aging investigations into long‐term aging of a natural ester (a)...Figure 11.6 (a) Changes in fluid DDF. Unit A was in service, unit B was stor...Figure 11.7 Oil quality measures as a function of transformer age (a) dielec...Figure 11.8 (a) Water content of oil, (b) oil temperature, (c) percentage sa...Figure 11.9 Dissolved gas concentrations for (a) methane, (b) ethylene, (c) ...Figure 11.10 Dissolved gas concentrations for (a) ethane and (b) hydrogen.Figure 11.11 One‐minute insulation resistance of transformer fleet.Figure 11.12 Ten‐minute insulation resistance of transformer fleet.Figure 11.13 Winding dielectric dissipation factor.
