Page 577 - Basic Electrical Engineering

Figure 6.23

cos ϕ is the no-load power factor of the transformer. At no-load, primary
0
winding copper loss is equal to

The wattmeter reading W indicates the power loss in the core as also in the
0
winding.

Core loss, or iron loss,

Example 6.7 A 100 kVA, 2400/240 V, 50 Hz transformer has a no-load
current of 0.64 A and a core loss of 700 W, when its high-voltage side is

energized at rated voltage and frequency. Calculate the components of the no-
load current and no-load branch parameters of the equivalent circuit.

Solution:

Neglecting the small amount of copper loss at no-load,