Page 547 - Basic Electrical Engineering

Figure 6.8 (a) Transformer on load; (b) simplified phasor diagram of a transformer on resistive–
inductive load

Using ampere-turns balance equation

or,

It may be noted that under load condition the primary current I is equal to
1
the sum of no-load current I and I′ , which is K times I . I′ is the additional
1
2
0
1