Understanding Thevenin Equivalent in Impedance Circuits: A Detailed Example - Prof. Tao, Thesis of Electrical Engineering

Download Understanding Thevenin Equivalent in Impedance Circuits: A Detailed Example - Prof. Tao and more Thesis Electrical Engineering in PDF only on Docsity! CONCEPTUAL TOOLS By: Neil E. Cotter IMPEDANCE CIRCUITS ‘THEVENIN EQUIVALENT Example 3 Ex: -—_—_————O a i 30 mH * —— 25 pF va) = 100 cos(IMa) V (+ 1. 240 kQ 2 pzix ob a) Draw a frequency-domain equivalent of the above circuit. Show a numerical phasor value for vs(t), and show numerical impedance values for R, L, and C. Label the dependent source appropriately. b) Kind the Thevenin equivalent (in the frequency domain) for the above circuit. Give the numerical phasor value for Vy, and the numerical impedance value of ZTh- Solin: a) First, we find phasors and z values, Vg = 100L0°V w= IM r/s Z_ = jwl =) IMr/s-3omi = } 30k @e= 7) = -j = ~ j= -j4OkKD we IMr/3-25 pF 2B Now we can Araw the freguency domain model: By: Neil E. Cotter IMPEDANCE CIRCUITS ‘THEVENIN EQUIVALENT Example 3 cont.) CONCEPTUAL TOOLS po < 320k 1x Ve= \o020°V 2HOoka SQ {| ub b) We first find Vi, = Vay, with no load connected across ayb. In this case, I, =OA since a,b = open. ———0 4 + J 20ka I, =0 so . LL + -j4o kno dependent Vee G Veh source loco Aisappears. + ov Z40kK2 3 | <0 #0 no V-drop - Lo lll We have a V-divider: Vay = Vz ~j4oko =¥ -j4oko2 a J4OK 2+) 30KD —j loko Va, = Vs = 4 (i0ozo*v) Vin = 40040" V