Question

In the circuit of Figure E5.1 (same as Fig. 5.1(a)), let Vs = 150 Volts, f = 60 Hz, R = 5 Ohms, XL = oL = (21f)L = 5 Ohms. P.1 Calculate the rms output voltage (Vor), the rms output current (Ior) and the output active power (rms). Use only the first and third harmonics of the output voltage and current. P.2 Calculate the load current at the instant of commutation. P.3 Calculate the diode conduction time. P.4 Draw dimensional curves (waveforms) showing the time variation of vo, io, vdsi, iswi, VDS2 and isw2.

Answer 1

Vs=1508 f= 60Hz R = 52 Xi =L=512 to PMS output voltage Vor= Vg = 150 = 75V Q 2 V(t) = Σ 2 Vg Singu t) n=113 n IT Vlt)- 2 Vs Sin wt + 2 Vs Sinßwt) T 3 IT Vilt) &x150 sinlwt) + 2x150 sin l3wt) 31 Vft) = 95.49 Sin (wt) + 31.83 sin (3w7 on = n tant XL = in tants = n(45°) R 0,- 45° 135° Z;=5.52 Ilt) = 2X150 siniwt-45) + 2x150 Sin (3ut-135) TET 311|23) Zz - J 52+ 152 - 15.811 2,= = 70 71 lolt) = 95.49 sin(wt-459 + 31.83 sin 13wt - 1359) 7.071 15.8.11 13.5 sin(wt-459) + 9.01 sin (3wt-135) lolt) = Poloms) = (13:5).195.49) ws(us$+(3483) (0.01) (05 (135) = 433.15 W Toloms) 2 t = 9.65 A

from above wt 14+) = 13.5 sin (wt=459) + 2001 sin (3wt-135) At load of Commutatio tolth 1315 sin450 totootsin/1359) 10.96 TA ant to ta 5 4 Diode conductontime = tant X2 = tant 5 = I R wt = T Diode conduction t = U = 2.083 millisecond 4 (217 (60) (9 6 75V time K -75Y Ź ܢܙܟܐ z AS W2

V. Dsi -75 -150 Nosa - -15ort sort