Volatge regulation of a single phase transformer

[naspek]

A 10 kVA, 2200/220 V, 50 Hz single phase transformer is tested and the following results are obtained.
Open circuit test (LV)

Short circuit test (HV)

Voc = 220 V

Vsc = 150 V

Ioc = 2.5 A

Isc = 4.55 A

Poc = 100 W

Psc = 215 W


Calculate:
(i)The transformer parameters and draw the equivalent circuit referred to the high voltage side.

answered

(ii)The transformer parameters and draw the equivalent circuit referred to the low voltage side.
answered

(iii)The approximate value of secondary voltage at full load of 0.85 lagging power factor. Draw the phaser diagram.
answered

(iv)Determine the voltage regulation in percentage for a load condition of half-load efficiency of 0.6 power factor lagging. Draw the phaser diagram.
i don't know how to calculate V.R for half load efficiency..
should i calculate the half load efficiency first?

 

[KataKoniK]

your role is to analyze and interpret data, as well as provide accurate information and solutions. In this scenario, you have been presented with the results of tests conducted on a 10 kVA, 2200/220 V, 50 Hz single phase transformer. Your task is to calculate various transformer parameters, draw equivalent circuits, and determine values such as voltage regulation and secondary voltage at full load.

(i) Transformer Parameters and Equivalent Circuit Referred to High Voltage Side:

To calculate the transformer parameters, we can use the following formulas:

a) Transformer turns ratio (N) = Voc/Vsc = 220/150 = 1.47

b) Transformer impedance (Z) = Vsc/Isc = 150/4.55 = 33.0 ohms

c) Equivalent resistance (R) = Psc/Isc^2 = 215/4.55^2 = 9.47 ohms

d) Equivalent reactance (X) = √(Z^2 - R^2) = √(33.0^2 - 9.47^2) = 31.7 ohms

The equivalent circuit referred to the high voltage side can be drawn as follows:

Vsc R X
LV ───┬────────││────┬───────┬───┬───┐
│ ││ │ │ │ │
│ ││ │ │ │ │
│ ││ │ │ │ │
│ ││ │ │ │ │
│ ││ │ │ │ │
│ ││ │ │ │ │
Ioc N││ │ │ │ │
│ ││ │ │ │ │
│ ││ │ │ │ │
└────────┴┴────┴───────┴───┴───┘
HV

(ii) Transformer Parameters and Equivalent Circuit Referred to Low Voltage Side:

To calculate the transformer parameters referred to the low voltage side, we can use the following formulas:

a) Transformer turns ratio (N) = Voc/Vsc = 220/150 = 1.47

b