Chapter 3: Q57P (page 157)
A two-winding single-phase transformer rated has an efficiency of when operated at rated load , power factor lagging. This transformer is to be utilized as a step-down autotransformer in a power distribution system. (a) Find the permissible kVA rating of the autotransformer if the winding currents and voltages are not to exceed the ratings as a two-winding transformer. Assume an ideal transformer. (b) Determine the efficiency of the autotransformer with the kVA loading of part (a) and 0.8 power factor leading
Short Answer
(a) The kVA rating of autotransformer is .
(b) The efficiency of the autotransformer is .