Transformer Short Circuit Current Calculation （变压器短路电流计算）.pdf

Transformer Short Circuit Current Calculation and Solutions Ling Song Bachelor’s Thesis Electrical Engineering Vaasa 2013 BACHELOR’S THESIS Author: Ling Song Degree Programme: Electrical Engineering Specialization : Electrical Power Supervisor: Lars Enström Title: Transformer Short Circuit Current Calculation and Solutions Date Number of pages Appendices 14 June 2013 31 pages 0 page Summary There are three goals for the thesis. The first one is to introduce types of short-circuits. The second one is to introduce the transformer short-circuit current calculations. And the last one is to find suitable reinforcement methods for the transformers which are running now. Using a comparative approach to analytic research, the advantages and disadvantages of different reinforcement methods can be analyzed. The result shows that the neutral reactor is the best choice to reinforce the S/C withstand capability : low cost, easy maintenance, high technique maturity and so on. Language: English Key words: short-circuit, transformer calculation methods, short-circuit withstand capability Table of the contents 1 Background 1 1.1 Introduction to the short circuit phenomenon 1 1.2 Needs of transformer short-circuit current calculation 2 1.3 Symmetrical components 4 2 Different kinds of short circuits 6 2.1 DC circuits 6 2.2 AC circuits 7 2.2.1 Single-phase circuits 7 2.2.2 Three-phase circuits 8 2.2.3 Development of short-circuit current 10 3 Calculation methods for transformers 13 3.1 Single transformer mod