Page 591 - Basic Electrical Engineering

Substituting values regulation

Example 6.17 A 230/115 V, 5 kVA transformer has circuit parameters as
R = 0.2 Ω, X = 0.8 Ω, R = 0.1 Ω, X = 0.2 Ω. Calculate the regulation of
1
2
1
2
the transformer at 0.8 power factor lagging. At what value of power factor
will the regulation be zero? Can the value of regulation be negative for any
power factor load ?

Solution

The transformation ratio,

Referring all the circuit parameters to the secondary side,

R″ = R″ + R″ 1
2
e
2
= R + K R 1
2
2
= 0.1 + (.5) × 0.2
= 0.15 Ω

2
2
X″ = X + X″ = X + K X = 0.2 +(0.25) × 0.8 = 0.4 Ω
1
2
1
2
e
Regulation