Question

a) Figure 3a shows the approximate equivalent circuit of a power transformer, where $n = \frac{N_2}{N_1}$ is the turns ratio. The equivalent circuit parameters have been determined experimentally showing the following results, including the percentage error values: n = 0.473±2% $R_c$ = 1080±2.5% $R_e$ = 0.658±3.5% Figure 3a - Approximate equivalent circuit of a power transformer. And the following results, including the percentage error values, were obtained in a test with a resistive load at full power: $V_1$ = 230V ±1% $I_1$ = 8.54A±2% $P_1$ = 1940W ±1.5% $V_2$ = 107V ±1% $I_2$ = 17.44±2% (i) Calculate the nominal value for the output power in the load test, and the percentage error. [2 marks] (ii) Calculate the nominal efficiency of the transformer from the measured input and output powers, and the percentage error. [2 marks] (iii) Determine the efficiency from the output power and the losses, with losses calculated from the equivalent circuit. [4 marks] (iv) Discuss the accuracy of the efficiency values found by the two methods. [4 marks] [Total 3a - 12 marks]

          a) Figure 3a shows the approximate equivalent circuit of a power
transformer, where $n = \frac{N_2}{N_1}$ is the turns ratio. The equivalent circuit
parameters have been determined experimentally showing the
following results, including the percentage error values:
n = 0.473±2%  $R_c$ = 1080±2.5%  $R_e$ = 0.658±3.5%

Figure 3a - Approximate equivalent circuit of a power transformer.
And the following results, including the percentage error values, were
obtained in a test with a resistive load at full power:
$V_1$ = 230V ±1%  $I_1$ = 8.54A±2%  $P_1$ = 1940W ±1.5%
$V_2$ = 107V ±1%  $I_2$ = 17.44±2%
(i) Calculate the nominal value for the output power in the load test,
and the percentage error.
[2 marks]
(ii) Calculate the nominal efficiency of the transformer from the
measured input and output powers, and the percentage error.
[2 marks]
(iii) Determine the efficiency from the output power and the losses,
with losses calculated from the equivalent circuit.
[4 marks]
(iv) Discuss the accuracy of the efficiency values found by the two
methods.
[4 marks]
[Total 3a - 12 marks]

a) Figure 3a shows the approximate equivalent circuit of a power
transformer, where n = (N2)/(N1) is the turns ratio. The equivalent circuit
parameters have been determined experimentally showing the
following results, including the percentage error values:
n = 0.473±2% $Rc$ = 1080±2.5% $Re$ = 0.658±3.5%

Figure 3a - Approximate equivalent circuit of a power transformer.
And the following results, including the percentage error values, were
obtained in a test with a resistive load at full power:
V1 = 230V ±1% $I1$ = 8.54A±2% $P1$ = 1940W ±1.5%
V2 = 107V ±1% $I2$ = 17.44±2%
(i) Calculate the nominal value for the output power in the load test,
and the percentage error.
[2 marks]
(ii) Calculate the nominal efficiency of the transformer from the
measured input and output powers, and the percentage error.
[2 marks]
(iii) Determine the efficiency from the output power and the losses,
with losses calculated from the equivalent circuit.
[4 marks]
(iv) Discuss the accuracy of the efficiency values found by the two
methods.
[4 marks]
[Total 3a - 12 marks]

Added by Bego-A R.

Question

Please give Ace some feedback