Exam Question
(a) Why is it important to maintain high efficiency of operation and low values of voltages regulation for power transformers (6)
(b) A 20KVA, 2000/220V, single-phase transformers has a primary resistance of 2.1Ω and a secondary resistance of 0.026Ω. The corresponding leakage reactances are 2.5Ω and 0.03Ω. Estimate the regulation at full load under power-factor conditions of: (10)
(i) Unity
(ii) 0.5 (lagging)
(iii) 0.5 (leading)