Question

0 Rm E Es N N2 2 9 a:5

For the following single phase transformer measurements
calculate each of the equivalent circuit parameters: Rm, Xm, R1, Xf1, R2, Xf2

Given:

No load:   V_oc = 120.77V         I_oc = 116 mA         P_oc = 3.0 w          Q_oc = 13.7 VAr         pf = .217

Full load:   V_sc = 8.0V         I_sc = 430 mA         P_sc = 3.4 w          Q_sc = .371 VAr         pf = .994

Answer 1

V_oc = 120.77 v I_oc = 116 mA P_oc = 3 c Q_oc = 13.7 VAR Cos Phi_oc = 0.217 I _w = I_oc cos phi_oc = 116 times 0.217 = 25.172 mA I_mu = I_oc sin phi_oc = 113.236 mA shunt branch R_o = v_oc/I_w = 4.797 k r x_o = v_oc/I_mu = 1.066 kr v_sc = 8v I_sc = 430 mA p_SC = 3.4 w Q_sc = 0.371 VAR cos phi_sc = 0.994 series branch z_sc = v_sc/I_sc = 8/430 times 10^-3 = 18.604 ohm R_sc = P_sc/I_sc^2 = 3.4 /(430 times 10^-3)^2 = 18.388 ohm x_sc = squareroot z_sc^2 - R_sc^2 = 2.826 ohm z_o2 = 18.604 ohm P_ow = 18.388 ohm x_o2 = 2.826 ohm