Dissertation > Excellent graduate degree dissertation topics show

Analysis on Moisture in Oil-paper Insulation Using Frequency Domain Spectroscopy

Author: LvZuo
Tutor: WuGuangNing
School: Southwest Jiaotong University
Course: High Voltage and Insulation Technology
Keywords: oil-paper insulation dielectric spectrum complex permittivity moisture content
CLC: TM855
Type: Master's thesis
Year: 2011
Downloads: 73
Quote: 2
Read: Download Dissertation

Abstract


With the rapid and steady development of Chinese economy, its power industry also developed rapidly over the past few decades. Now the number of power transformers on operation is increasing. The safe operation of power transformers is the first defense system to avoid the major accident of grid, if a large power transformer in the system run-time failure, it may lead to blackouts, and the maintenance generally takes six months or more. So it may cause large loss to the national economy, and bring a huge inconvenience to the people. At present oil-immersed transformer is the most widely used in power system, and oil-paper insulation of oil-immersed transformer directly affects the electrical performance and operational life. Water is an important factor which impact performance of oil and paper insulation, and water will reduce the breakdown voltage of the insulation system and increasing dielectric loss. When the oil in moisture content exceeds a certain threshold, the insulation performance of device will greatly reduce. Oil-paper insulation system absorbing water caused degradation, aging, increased dielectric loss, lowed the insulation resistance, and PD starting voltage was declining, leading to the operational life of the transformer be seriously affected. Therefore, testing the whole water content of oil-paper insulation system has a great significance for transformer’s safe and stable operation.The moisture content of transformer oil can be tested by collecting sample and laboratory analysis, and generally testing methods is the Karl Fischer titration—KFT. But once the transformer is operational, due to inability to obtain samples of the insulation paper, to estimate the moisture content of paper is more difficult. The traditional method is to determine water content in oil and indirect access water content values through water content distribution curve. So if we can directly analyze the oil-paper insulation system posed by paper/oil insulation, it will be very important the for analysis of water content particularly.This paper used the dielectric spectrum method (Frequency Domain Spectroscopy) which basis of the dielectric response theory, with laboratory equipment and facilities, built the experimental test platform for oil-paper dielectric response test. Simulated the oil-paper insulation system model by Ansoft12 Maxwell2D electromagnetic simulation software to study the the electromagnetic field distribution between the electrodes of dielectric plate capacitance sensor, the current density and dielectric loss distribution oil-paper insulation. Simulated the actual operation of the transformer, and accelerated thermal aging tests by laboratory simulation of transformer oil-paper insulation aging, set the oil-paper insulation system directly as a measured object, studied the dielectric spectra at different temperatures and different conditions of water content variation; analysis the dielectric properties of oil-paper insulation, got its information of the water content, so it can supply an important basis for the correct diagnosis of transformer insulation condition, assessment of transformer’s remaining life and improving power supply reliability.

Related Dissertations

  1. Studies on the Drying Modle and Technology of Tilapia by Heat Pump,TS254.4
  2. Research on New Method for Measuring Dielectric Constant of Microwave Samples,O441.6
  3. Study on Bio-drying of Paper Mill Sludge,X793
  4. Research on Overburden Motion Laws and Support Optimization in Paste Backfilling Face of Daizhuang Coal Mine,TD355
  5. Characteristics of Soil Respiration, Grain Yield and Water Use Efficiency in Crop Fields under Different Mulching Modes and Crop Conditions,S154
  6. Research on Wireless Low-power Powder Material Moisture Meter,TH83
  7. WEB-based Panzhihua Municipal Meteorological Information Management System Design and Implementation,TP311.52
  8. A Method to Measure Soil Moisture Based on Terahertz Transmission TDS Spectrum,S152.7
  9. Based on polarization and depolarisation current law status of transformer oil-paper insulation,TM855
  10. Study on the Biomass of Different Origins in Moso Bamboo Base on Fertilizer Regulation,S795
  11. Study on the Impact Characteristics of Rice Kernels,S511
  12. Application of ANN for the Prediction of Water Content in Geophysical Exploration,P641.7
  13. Study on Ionizing Radiation Treatment of Residual Sludge,X703
  14. Research on Efficiency of Sludge Sedimentation and Dewatering with Natural Freezing/thawing Treatment with Natural Freezing,X703
  15. The Research on Water Content of Wood During High Temperature Treatment Process,S781
  16. Study on Degradation Assessment of Oil-Paper Insulation and Feature Extracting of Partial Discharge of Transformer Based on Chaos Theory,TM401.2
  17. Influence of Surface Energy on Fracture Energy and Strength of Cement Based Materials,TU528
  18. Gravelly clay physical and mechanical properties and Construction Control Technology,TV221.2
  19. Laboratory Test Study on Engineering Properties of Low Liquid Limit Silt,U416.1
  20. Detection of Soil Information Based on Spectral Analysis and Digital Image Processing Technology,TP274
  21. Experimental Study on Dynamic Shear Modulus and Damping Ratio of Loess under Complex Initial Stress States,TU411.8

CLC: > Industrial Technology > Electrotechnical > High Voltage Engineering > High - voltage insulation technology > Insulation test and inspection
© 2012 www.DissertationTopic.Net  Mobile