Question

1. The Y-Y three phase balanced system has the following parameters. (30pts) Vo_an/bn/cn = 12Vrms Lo=3mH Ro=5k2 RLINE =8k2, Freq = 300KHz. RLOAD =20k.2 LLOAD=9mH CLOAD =0.001uF RLINE_A RLOAD_A Roa La LLOAD_A CLOAD A N CLOAD_BY CLOAD_C Vb bn LLOAD_C LC LLOAD_B Ro C HRLOAD_C RLINE_B Ro B RLOAD_B RLINE_C

C) is this an inductive or capacitive load? why?

d) what is the power factor of the load.

Answer 1

R_load = 20 K ohm, L_load = 9mH, L_load = 0.001 mu F frequency = 300 KH_z Z_load per phase = R + j(wL-1/wc) = 20 times 10^3 + j(2 pi times 300 times 10^3 times 1 times 10^-3-1/2 pi times 300 times 1063 times 0.001 times 10^-6) = (20000 + j(16956-530.7855) = (20000 + j 16425.214) = (20 + j 16.425)4 ohm (c) As Imaginary part of Z_load is positive, it is an inductive load (d) Power factor of load implies cos(tan^-1(16.425/20)) = 0.77 lagging