Single Phase Transformer

UNIT IV

Chapter 6

Single Phase Transformer

Syllabus

Construction and principle of operation, equivalent circuit, phasor diagrams, testing - polarity test, open circuit and short circuit tests, voltage regulation, losses and efficiency, all day efficiency, back-toback test, separation of core losses, parallel operation of single-phase transformers, applications of single-phase transformer.

Contents

6.1Introduction ....6-2

6.2 Principle of Working.......6-2 Dec.-13,17, May-13,14, Marks 8

6.3 Parts of Transformer... 6-3

6.4 Construction of Single Phase Transformers... 6-6Dec.-08, May-13, Marks 8

6.5 E.M.F. Equation of a Transformer......6-8 May-04,05,07,12,14,15, Nov.-07, Dec.-12,17, Marks 10

6.6 Ideal Transformer on No Load ..........6-11

6.7 Practical Transformer on No Load .........6- 12 Dec.-06,14, May-08, Marks 8

6.8 Transformer on Load(M.M.F. Balancing on Load)............ 6 – 13 May-08, Dec.-14, Marks 8

6.9 Effect of Winding Resistances..6-16 May-14, Marks 8

6.10 Effect of Leakage Reactances.. 6-18

6.11 Equivalent Impedance ..6-19 May-03, Dec.-05,19, Marks 8

6.12 Phasor Diagrams for Transformer on nolainens Load..6 21 Dec.-02,17, May-06,10,14, Marks 8

6.13 Equivalent Circuit of Transformer. . . . . . . . 6-23 May-03,04,09,10, Dec.-04,08,09,11,12, Marks 8

6.14 Voltage Regulation of Transformer.. 6-25 May-06,07,09,14,17,19, Nov.-07, April-04, Dec.-07,10,11,17,18, Marks 10

6.15 Losses in a Transformer...........6-33

6.16 Efficiency of a Transformer......6-34 Oct.-02, April-98,99,03,04, Dec.-97,03,07,08,13,15,19, May-05,07,08,12,15,19, Nov.-04, Marks 10

6.17 Polarity Test. . . . . .6- 41

6.18 Open Circuit and Short Circuit Tests..... 6-41 Dec.-06,07,08,10,15,16, 19, May-08,10,11,12,13,16, 17, Nov.-06, Oct.-02, Marks 16

6.19 Sumpner's Test (Back to Back Test) ...6 50 Dec.-16, 19, May-03, 17, Marks 8 6.20 All Day Efficiency of a Transformer....... 6-53 May-07, Dec.-09,10,18, Marks 13

6.21 Separation of Core Losses..... 6-58 May-10, 11, Dec.-13, 15, 18, 19, Marks 15

6.22 Parallel Operation of Transformers . . 6-60 Dec.-03, 05, 08

6.23 Conditions for Satisfactory Parallel alqoning ar Operation..........6-61 Dec.-02, 03, 05, 08, 19, May-07, 15, Marks 16

6.24 Parallel Operation of Two Ideal gro ov Transformers..6-62 May-15, Marks 4

6.25 Parallel Operation of Transformers with Equal Voltage Ratios . . . . ... 6-63

6.26 Parallel Operation of Transformers with inerals Unequal Voltage Ratios ... ...6-64 Dec.-05, 06, Marks 12

6.27 Current Inrush Phenomenon(Switching Transients). ...... 6-69 May-15, Marks 6

6.28 Applications of Single Phase Transformers.....6-70

6.29 Two Marks Questions and Answers...... 6-71