Question

Exercise 2: (Autotransformer configuration for nominated output voltages) A 600V source is available, and it is desired to use the transformer in previous exercise in two separate applications to: (a) transform 600V to 750V; and (b) transform 600V to 480V. Show on sketches how these configurations can be separately achieved without exceeding the ratings of either winding, and calculate the maximum safe output volt-amps in each case. Under maximum load, identify which (if any) of the currents in the two sections of the winding will carry their maximum permitted current.

Answer 1

sol: given 600V is a available 8009166 Designing an auto-twansformed with Goov as source Voltage g transtoom boov to 750V : beets take βουν και a general transformer with λουηδο. normal Transformers 15KVA - 1 =25A 100 A Goor 1 E 1609 ve I = 15 KVA_= 25A, IL = 15kVA 600 50 =100A 600V to Designing an Auto - Transformer with 750V 600 V. primary Voltage 750V-7 secondary Voltage

100A A DE Thoi ooo Source 600N Manimum KVA of auto-transformar a 15 KVA ke huyor = hotell MaxkVA = 15 = 5X15 1-1% Max. KVA = 75 KVA O section AB Garry's Corrent = 25 A section GD Carry's Goorrent = 100 A, @ .: 600X125 = 750X100 = 75 KVA i input KVA = Output kVA), & Transformer 6oov to ABOV beto us take a general transformer with Good as source and wood Voltage 120v.

normal Transformer : okraa 15 KVA 25 A To af load 15 KVA) 600V 18 D _ 1 I = 15 KVH = 25A, I = 15kva = 125 A 120 600 Designing an auto- Toranstormeer with I 1251 book to 490 V:- с If 100A 30-120 My load - 4807 600 V- 3 250 A3.+ THY 600 46. " Maximum KVA of auto-transformer = 15 ky KE 480 = 4 Max. kva of Auto - TIF = -15% € 60KVA 1-5% In Go KVH = 1250,- I = 60KVA = 100 All Man. KVA § 60 KVA → ☺ section AB Carry's current = 205 A,, section Go Garry's current = 125A 6 L. 600X100 = 480X125 = 60 kVA :. inport KVH = Output kVA 600