aged este...Table 4.14 Equivalent electrical circuit parameters.4 Chapter 6Table 6.1 Propagation velocities for different streamer modes.Table 6.2 Sequence of phenomena that occur in the point‐to‐plane electrode s...
5 Chapter 7Table 7.1 Characteristics of base oil samples.Table 7.2 Main parameters of the three base oils.Table 7.3 Viscosity and tanδ of mixed oil with different proportions of palm...Table 7.4 Results of further adjustment on the proportion.Table 7.5 IOT of mixed oil with different antioxidants.Table 7.6 IOT of mixed oil with different antioxidants.Table 7.7 Parameters of the novel three‐element mixed insulation oil.Table 7.8 Parameters of cellulose polymers.Table 7.9 Parameters of the three‐element mixed insulation oil and 25# miner...Table 7.10 Sample grouping and oil treatment.Table 7.11 Test method and standard of parameter measurement.Table 7.12 Fitting results of DP values with kinetic equation.Table 7.13 Expected life of cellulose paper in thermal aging test (130 °C).Table 7.14 Calculated and measured DP values after 90 days.Table 7.15 Addition mass ratio of H2O and H3O+ in two insulation oils (%).Table 7.16 Simulation parameters.Table 7.17 Hydrogen bonds and interaction energy in three‐element mixed insu...Table 7.18 Hydrogen bonds and interaction energy in mineral oil–paper system...Table 7.19 Dielectric loss of the new three‐element mixed insulation oil‐imp...Table 7.20 Relative permittivity of insulation materials.Table 7.21 Electric fields (kV/mm) at the middle of the oil gap and the oil‐...Table 7.22 The equivalent flashover voltages at 5% probability and average v...Table 7.23 The equivalent flashover voltages at 5% probability and average v...Table 7.24 The equivalent breakdown voltages at 5% probability and average v...Table 7.25 Magnitude of electric field intensity (Em ), the components on x‐...Table 7.26 Magnitudes of electric field intensity in oil and pressboard, 0.1...Table 7.27 Comparison the parameters of distribution transformer filled with...Table 7.28 The measurement results of the performance parameters for the new...Table 7.29 Content of dissolved gases in oil after multiple times of surface...Table 7.30 Content of dissolved gases in oil after multiple times of surface...Table 7.31 Content of dissolved gases in oil after multiply AC breakdown of ...Table 7.32 Content of dissolved gases in oil after multiply AC breakdown of ...Table 7.33 Dissolved gases in oil after multiply positive polarity lightning...Table 7.34 Dissolved gases in oil after multiply positive polarity lightning...Table 7.35 Boundary settings of C2H2, H2, C2H4 triangle.
6 Chapter 8Table 8.1 Structure of glycerol, fatty acid, and triglyceride molecules [9].Table 8.2 Properties of commonly used nanoparticles.Table 8.3 Comparison of physical properties of mineral oil and natural ester...Table 8.4 Comparison of AC breakdown voltage of mineral oil and natural este...Table 8.5 Thermal conductivity of commonly used solids and liquids [57].
7 Chapter 9Table 9.1 Literature survey on nanofluids.Table 9.2 Arrhenius parameters for synthetic ester nanofluids.Table 9.3 Slope “m” and mobility under positive and negative polarity.Table 9.4 Number of corona discharges activity per second with synthetic est...
8 Chapter 10Table 10.1 Example of fault detected by Duval's triangle.Table 10.2 Example of fault detected by Duval's PentagonTable 10.3 Liquids classification and acidity values (measured).
9 Chapter 11Table 11.1 Power transformers analyzed in this study.Table 11.2 Comparison of heat run temperatures.Table 11.3 Dissolved gas content of oil in parts per million (ppm), taken ne...Table 11.4 Fluid properties.Table 11.5 90th percentile values determined from data.
List of Illustrations
1 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
