Ch - 4

Single Phase Transformer

Prepared By,Mr. Kapil P. RadadiyaAITSDS, Rajkot

Vector Diagram of 1-Φ Transformer with Resistance and Reactance (For Unity Power factor)

Voltage Regulatiion of 1-Φ Transformer

V2

I2

I2R02

I2X02

I2Z02

0V2

O A

B

C

DMN

L

Φ2Φ2

I2R02CosΦ2

I2X02SinΦ2

Φ2

Derivation of Voltage Regulation Approximate Voltage Drop

0V2 – V2 = AN = AD + DN= I2R02CosΦ2 + I2X02SinΦ2

% V. R. = 0V2 – V2 / 0V2 * 100 = I2R02CosΦ2 + I2X02SinΦ2 / 0V2 * 100

I2R02CosΦ2 = Resistive voltage drop I2X02SinΦ2 = Reactive voltage drop

For Leading Power Factor Load

% V. R. = I2R02CosΦ2 - I2X02SinΦ2 / 0V2 * 100

In General Voltage Regulation can be given by,

% V. R. = I2R02CosΦ2 ± I2X02SinΦ2 / 0V2 * 100