Answer to Question #137475 in Electrical Engineering for Christine Genny

Question

A balanced delta connected load is supplied from a 220V, 60Hz source thru a line with impedance of 0.5 + j0.8 ohm. If the power consumed by the load is 3 KW at 0.8 power factor leading. Determine the line currents and phase currents in phasor form. CBA Sequence

Answer 1

Since it is necessary to find currents in the phase form, then to begin with we find the phase current through the ratio $I_{phasor}=\frac U z$ , where $U$ is the voltage, $z$ is the impedance, the voltage in the phase form $U = 220\times e ^ {j\times 0}$ ;

impedance in phase form $z = \sqrt {0.89 }\times e ^ {j\times atan (\frac 8 5)}$ therefore

$I_{phasor}=\frac {220\times e^{j\times 0}} {\sqrt {0.89}\times e^{j\times atan(\frac 8 5)}}=123.6-j \times 197.75$ A;

Since the phase current and the linear are related by the relation $I_{line}=I_{phasor}\times \sqrt {3}$ , then

$I_{line}=(123.6-j \times 197.75) \times \sqrt{3}$ $=214.08-j \times 342.51$ A.