Question

hot answere A 3-phase, 10kvA, 400 Vrms (line-to-line), 50 Hz synchronous gené rator has negligible stator Winding resistane and and a synchronous inductance of 10mit per phase. Determine the power angle and the excitation voltage requined to achieve a unity power bactor. Hot answered ERVICES - → Two Coils are wound on a toroidal Cove as shown below. The core a has a square cross section. The coil Currents are i, = 0.25 A robin N = 500 turns 3 N2=400 turns. The relatively permeability of the come! is 4500, Determine the flux in the core.

Answer 1

Solution Gurven dala TOKUA, 3-0, 400 yms (line to line), 50HZ Synchronous generator r. 0 , L=10mH /per phase ; pof=1 Xg = jwL = j280fl = j215x50x10-2 r llene . [XS = jt Eequivalent diagram jTj314 m > + 21 400 ELS iz 3) VI VI I2 = 10x103 I. = 1443 20 104 Njх ҷоо ELS = V+ + j' I_ * 3.14 + 3.14 x 14.43 L90 ELE = 230.94 + j45.34 | ELS = 235.34 (11.10 Hence lexuitabren Voltage = 235-34] power angle = 11-10° Given Diagram N = 500 Na = 400 i = 0.254 2 = 0.6A relative permeability Mr=4500 If Side of square = 12cm - 8cm = 4cm

Total mmt Flux in core = Reluctance of core is 10 9 (" ه ا direction and current direlhion Since Coids add up So net mmf will N,1, + N₂ Iz ا ا ا ا ا ا ا ر سا مرا را در را Molly A es Meun length of core (dotted line in figure) Radius of dotted cirde = loom { 1.e. 8 + 4 2 = loum I - 27TY - 201T X10-2m A = Square of side of square = 4x4 com? = 16810m - Mo = 41TX107, dy = 4500 Given 500 X 0-25 + 400 x 0.6 20TX 10-2 411X10-7x4500 x 16x1019 365 x 41 x 107x4500x16x204 X16X104 10-2 - 2011 ou 2-628 X10 برا، رات را با به رامبل OS 5 = 26-28x103 = 15.256 m weber core = 5-256 mili Weber Flux in "