Loading...

Analysis of Distribution Transformer Derating Under Non-Linear Loads

Ghazizadeh, Milad | 2014

748 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 45984 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Oraee Mirzamani, Hashem; Feyz, Javad
  7. Abstract:
  8. Transformer is one of the most important equipments in power systems which its reliable performance plays a vital role in increasing of power system's reliability regarding to its importance. Traditionally, designers of transformer consider transformer's parameter under "Usual Service Conditions" but the challenge which has been brought up in contrast to this approach in recent years, is wide applications of non-linear loads in different levels of power systems, especially in its distribution level. Use of non-linear loads leads to flow of non-sinusoidal load current. Hence, Power Quality indexes have been distorted in power systems. Passing non-sinusoidal load current through transformer leads to higher losses in it. Increasing of transformer losses causes temperature rise in its different parts which eventually leads to its premature destruction. The most common method for overcoming to this challenge is derating of transformer. Therefore, this thesis by casting light onto available methods and expressing the advantages and disadvantages of any method, eventually provides a mixture derating method using analytical and Finite Elements methods. Using this novel method, winding eddy current losses are precisely estimated considering transformer's geometry specification and used material properties. With the intend of derating of distribution transformers, by adopting an innovative procedure based on hot spot concept, electromagnetic and thermal-insulation principles are employed till in addition to defining a new factor, the comprehensive and economical derating method is provided. Finally, the results of distribution transformer derating using proposed method under two different approaches with attendant IEEE standard will be compared
  9. Keywords:
  10. Nonlinear Load ; Hot Spot ; Distribution Transformers Derating ; Transformer Losses ; Nonsinusoidal Load Current ; Winding Stray Losses

 Digital Object List

 Bookmark

No TOC